text:
How much light do I need?
I make videos showing myself playing guitar. I need advice on purchasing lighting. Budget: $100.
How much light do I need? I read articles about various lighting types, but they rarely give any specific watt or lumen values.
I don't want to sweat in super bright light. I can accept some shadows and I prefer a natural look. I just want my camera to function without much noise, with decent color reproduction. I also don't want to think much about the lights (e.g. adjusting position, turning on and off). I want to "set and forget" and focus on playing music.
I record indoor, in the evenings, with no sunlight. The lights I buy would be the only light source.
I presume the light shouldn't be closer than 5' from myself otherwise it will be strongly nonuniform (e.g. shining brightly on one end of my guitar only, if positioned on the side). Sometimes I also move a bit while playing (say ±1'), and I don't want to worry about moving in and out of the beam of light too much.
I found the following options within my budget:

A small softbox (20–30 inch), perhaps accompanied with another small light. Is it even large enough for my needs? If I position it farther from myself, should I compensate with a stronger light bulb? How strong? Would heating up be a concern in prolonged operation?

A pair of umbrellas. Quite some flexibility in this price range, but again I'm clueless about how strong the light bulbs should be.

A LED panel, perhaps accompanied with another small light. LEDs seem to have excellent CRI, but also seem to be dimmer (20–40W in this price range; yes I know LEDs give more lumen per watt, but it still seems low). Specifications often don't even mention wattage! Is that sufficient for the main light? How badly do I need to diffuse the light, and if I do, do I need to compensate with more power?

There are several things to consider when purchasing and setting up lights.
As for the brightness, the brighter you're lit up, the less noisy your image will be. Brighter light will also allow your camera to reduce it's aperture. The smaller aperture will make the area that is in focus bigger, giving you more room to move around in and still be in focus. There are several factors that go into how bright you will be. When I shoot video for clients, I use 1000W incandescent to light up a room that is anywhere from 5x5ft to 20x20ft. Any bigger than that and I'll probably bring in more lights for the main light source. If you are using LED, 1000 incandescent (tungsten) watts are about equal to 167 LED watts.
As for the setup, if you are moving around in your videos and trying to make sure your space is evenly lit, I suggest pointing the light at the ceiling instead of at you as long as your ceiling is white. This makes the light even and look natural. When doing this, remember that the lit up spot on the ceiling is now your light source. Make sure the light source (lit spot on the ceiling) is in front of you and (in my preference) off to one side. Play around with the positioning to your liking, but look up images of "loop lighting" (off to one side) and "butterfly lighting" (centered) to see the styles of lighting I'm talking about. The most important takeaway from those is the small nose shadow on the face. Those two style are what's used for most photography and video of people outside of mood lighting. I always diffuse the light with the ceiling, a soft-box or an umbrella when shooting, unless there is good reason to use hard/direct lighting.
If you do not want to use the ceiling method, both softboxes and umbrellas work well. The one place I see people make mistakes with the softboxes is placing the box too close the subject which ends up making the light vary too much when you move around and makes the background a bit dark compared to the subject. Being too close with the light also makes the lite seem like a light you set up for the video and not natural lighting.
Now for incandescent vs LED. Personally I never use LEDs for video. There are several reasons for this. First off, LEDs are blinking lights. If you don't believe me, put one on a rope and swing it in a circle and you'll see a dotted path. What this will end up doing is making your strumming hand (and any other decent movement) look like it's a multiple exposure, where you have several sharp images of your hand instead of a smooth motion blur. Some newer LEDs have a refresh rate fast enough to make this a non-issue but they usually cost a pretty penny. The other big issue with LEDs is the color they put out. Incandescent bulbs put out a very wide gamut of color, meaning every visible color is being put out from the bulb. LEDs only put out a single narrow color, or in the case of some LED arrays, a group of narrow colors. The lack of a full gamut, means that some colors will look muted while others are very vibrant. Skin tone can end up looking dead-like. This makes color correction extremely difficult and something many musicians do not want to deal with. Of coarse the down side to incandescent is the heat it puts off. How much of a problem the heat will be depends on your space. A small room will heat up quickly. If you're in a living-room, you probably have enough space for most of the heat to dissipate and for the air conditioning to take care of the rest. If sweating becomes a mild issue, get some colorless power from a theater makeup store to apply before videos.

LED panels are a lot better than that, these days. They're replacing the old Kino Flo 4-banks (to be phased out June 2020) on even the highest-budget productions & if they're good enough for David Yates &c they're good enough for me. They're temperature, brightness (& now full-colour)  variable & have no discernible flicker, movie or stills. I've a couple of cheaper units, about $£€ 150 each, also totally flicker-free. This article has plenty of info from beginner up, with recommendations - https://www.studiobinder.com/blog/best-led-video-light/ (no affiliation)


text:
Need help to fix a broken MP4 which lacks a MOOV atom
Please be forgiving to a video file format newbie, who has travelled far and wide all over the Web in search of a relatively simple question and hoped to get an answer (even a fairly complicated one would be fine!):

TL;DR: I have a broken MP4 which lacks a MOOV atom (neither at the beginning
  nor at the end). So, how do I create a new MOOV atom in order to fix the file?

And now for the expanded question (if you bother to read it), which shows the homework I've done so far...
What solutions I've found so far...
A quick search just here on video.stackexchange.com will get you a few dozens of similar questions and variations on the theme; do that search on Google, and you'll get a few hundreds more; even Quora has a few answers... To summarise most of them, here is what they usually say:

"MP4 files can have a MOOV atom at the end (that's the usual way) but also at the beginning; here's a selection of N solutions to move the atom from one place to the other" (no, they aren't useful if you have no MOOV atom whatsoever)
"You can use ffmpeg (or a gazillion similar utilities — most of which will use ffmpeg's library anyway — or even VLC [some versions seem to have a way to automatically fix broken videos — not my case, though]) to somehow magically extract part of your broken file, split it into bits, or even split it into individual frames, then reencode, and eventually you'll get a few sequences of frames out of the corrupted video, or even, with luck, a bit of continuous video which will play (sometimes only under VLC, sometimes only under mplayer, sometimes requiring [insert favourite video player here])" (all these suggestions are very nice, but all assume that at least there is a MOOV atom somewhere — or else all will fail)
"Some tools (or commercial applications) can deal with corrupt data on faulty disks/pen drives/memory cards, by reading sectors directly from the underlying media and bypassing the FAT or whatever filesystem layer is used by the operating system, thus at least being able to recover part of your video, even if it's (possibly) out of order, incomplete, etc." (this may all be true, but does not help in my case, where the file is pristine and there is no problem whatsoever with the hardware where it's currently stored — the file is just missing a MOOV atom, so none of these tools will help)
"A few tools, such as untrunc, may be able to repair a broken file, especially if the MOOV atom is missing at the end of the file because the video camera abruptly had its power cut (or some similar situation). There are also several commercial software solutions available which do the same (and are easier to use) or even web-based ones. Commercial applications usually have a demo/trial mode where you can at least recover some data to give you an idea if your particular file is repairable or not. Usually, such software requires a video made by the same video camera under the same circumstances, to be able to push the missing data from that video to the corrupt file." (so far, I've not managed to find the 'magic tool' which does exactly what is claimed... all I've tested will fail with a missing MOOV atom... no matter if the 'test video' has it, which could easily be copied — assuming that this will 'fix' anything, of course).

Why none of the above actually helped me out
Things may be explained a bit differently in one case or another, but after going through dozens of descriptions of 'solutions' out there, I'd say that most will fall in one of those four cases. The fourth case, of course, is the only one that may help in my case, but, so far, I've tried pretty much everything which can run on a Mac — aye, including a few commercial apps — and none will deal with the issue.
I've also found out that many of these tools — especially those that are commercial! — are little more than a GUI to ffmpeg/libav. Some even use hopelessly outdated versions of these; in some cases, they're compiled with them statically; in other cases, ffmpeg and its friends are packed with the application, which just calls it with whatever special parameters the developers have figured out that might help (or even work!) in most cases.
While I'm pretty sure that some of the tools I tried out may have non-ffmpeg/libav code, they haven't worked, either. What I seem to be able to conclude is that anything depending on ffmpeg/libav code will not work without a valid MOOV atom. Therefore, the trick — if there's one! — is to somehow 'extract' a MOOV atom from either a different file and/or re-create the MOOV atom from the existing data. While the former seems to be the most popular approach (and, as said, I've tested a dozen or so apps using that approach), none worked in my case; as to the latter approach, if it exists at all, it's not explicitly named in any of the tools I've tested out, so I cannot say if that's possible at all (i.e. it may be a very obscure and undocumented feature of ffmpeg but, so far, I have not come across an answer which mentions such feature; of course, commercial tools, for obvious reasons, may simply not document what exactly their tool is doing 'under the hood').
Whew. Wordy, I know! Let me just give you some assurance that, although I hardly understand what I'm talking about — namely, the complex structure of an MP4/MOV file — I have certainly done my best to figure out what is wrong with my file, and why all attempts I've tried out so far have utterly failed. My apologies in advance if I'm assuming wrong things about the MP4 format and/or just saying rubbish which makes no sense (such as 'reconstructing a MOOV atom out of existing frames on a movie' — perhaps such a thing is impossible to do, for reasons I don't understand).
What I know about my file...

It certainly has data in it (i.e. not just garbage). Several of those utilities correctly figure out that it's a QuickTime stream; some can even identify a few atoms.

Here is an example from mp4dump:
[ftyp] size=8+12
  major_brand = qt
  minor_version = 0
  compatible_brand = qt
[wide] size=8+0

And this is the output from mp4info:
File:
  major brand:      qt
  minor version:    0
  compatible brand: qt
  fast start:       yes

No movie found in the file

(weird that it knows about 'fast start', though...)
Here is the output of my own hacked utility (see below):
[ftyp]
        Major brand: qt
        Minor brand: 0
        Compatible brands: [qt  ]

[wide]
        Size: 8
        Start: 20

[mdat]
        Size: 2305577342
        Start: 28

But none can find a single MOOV atom. Photoshop can import 'noise' from some frames — they look like frames, though, just so noisy that they become 'random pixels', that is, it's pretty much impossible to figure out what exactly that frame is supposed to be...

I have 'similar' files, generated by the same video camera (the iPhone 8's 'selfie' camera in landscape format), so I can easily extract an existing MOOV atom (or any other) and 'glue' it elsewhere on an existing file, a procedure many of the mentioned tools consider a possible solution to a 'missing' MOOV atom — but none are actually able to do that with my video...

What I can theoretically do to fix things
(or: An attempt to start to answer my own question...)
I'm just a humble amateur programmer, which means that fully developing a new tool in order just to fix my own video is very likely out of the question (and furthermore I have no time for that). The best I can promise to do if nobody has an answer is to figure out how MP4 encoders actually generate a MOOV atom from the existing data and see if I can adapt an existing tool to 'regenerate' the MOOV atom from scratch (note: I did hack it a bit to show the contents of all atoms it can find inside the file when the MOOV atom is missing, the output of which I've given before)... alas, I think that this might be impossible if one does not know some basic things about the video file itself (after all, these 'basic things' are stored on the MOOV atom!), but I'm happy to be proven wrong on that — especially because I can 'guesstimate' many of those 'basic things' by simply reading the MOOV atom from a video file generated under similar circumstances...
Here is such an example (tracks 3 and 4 are not really fundamental):
found avc1
File:
  file Size:    16072874
  brands:   qt  , [qt  ]

Movie:
  duration: 6859 ms / 600 (00:00:11:431)
  fragments:    false
  timescale:    600

Found 4 Tracks

Track 1:
  flags:    15 ENABLED IN-MOVIE IN-PREVIEW
  id:       1
  type:     Video
  duration: 6859 ms
  language: und
  width:    1920
  height:   1080
  media:
    sample count:   184
    timescale:      600
    duration:       6859 (media timescale units)
    duration:       11431 (ms)
  display width:         1920
  display height:        1080
  frame rate (computed): 16.10

Track 2:
  flags:    15 ENABLED IN-MOVIE IN-PREVIEW
  id:       2
  type:     Sound
  duration: 6859 ms
  language: und
  width:    0
  height:   0
  media:
    sample count:   495
    timescale:      44100
    duration:       506880 (media timescale units)
    duration:       11493 (ms)

Theoretically, with a bit more hacking, I can also extract the precise position where each track begins and ends (assuming that's how the MP4 format works!) and whatever information may be needed to 'reconstruct' the MOOV atom...
What help I actually need
I do have access to the PDFs with the ISO/IEC 14496-12 standard which defines the MP4 file format but I haven't read them yet. In essence, what I need to understand is how MOOV atoms are created/generated from existing video data. I'm fine with downloading and installing any tool which I haven't mentioned previously (so long as they work either under macOS or any non-GUI Linux — I might be able to temporarily get access to a Windows 10 machine if I'm assured that there is a solution that will work under Windows). I'm also willing to change or adapt existing open-source tools, so long as I can get some pointers on how to actually 'generate' the MOOV atom from existing video data (preferably written in Go or PHP, but I'm ok with C, C++, C# or Python [in decreasing order of preference], or, well, Perl or JavaScript... I'm just not willing to install Java :-P and I'd really need a lot to get persuaded to use Ruby, Rust, or whatever language is currently fashionable...).
If you read until the end, my heartfelt thanks in advance :-)

I'm scared to ask, but curious, how did you end up in this situation, what is the video content you are recovering?

Care to share the corrupt file?

cough thanks for your questions/suggestions but let's just say that this particular video might not be safe for the workplace...

@RyanTheLeach, as far as I could figure it out, what seemed to have happened was that the video capturing app on my iPhone unexpectedly crashed, just seconds before the end of the movie... so it had already captured all the data, but still hadn't finished writing out the index. I have no idea if that makes sense or not to you guys, but it seems that this was the case. In other words: if the index had somehow 'survived' the crash, I would probably lose some video (and sound sync might be gone, too), but at least I would get something. But without a MOOV atom... no luck!

duplicate of How to recover a broken mp4 file: moov atom not found at unix.stackexchange.com - especially since you're looking for a linux/macos solution
limitation: the untrunc tool needs a working similar video file

As you said you have similar files, you may try the following:
1) any good mp4 file with the same resolution and bitrate to generate the header files:
recover_mp4.exe good.mp4 --analyze

2) recover streams from the corrupted file, for example:
recover_mp4.exe bad.mp4 recovered.h264 recovered.aac

3) join audio and video with ffmpeg:
ffmpeg.exe -r 30 -i recovered.h264 -i recovered.aac -bsf:a aac_adtstoasc -c:v copy -c:a copy recovered.mp4

recover_mp4 : https://codecpack.co/download/recover-mp4.html
ffmpeg: https://www.ffmpeg.org/
I've just covered a mp4 with the above method - although sound is still corrupted, video is all good.

Sorry for just answering today… I did, in fact, come across that tool; I just had two problems with it — there is only a Windows version for it (I have a Mac, an iPad, an iPhone, and easy access to all sorts of Linux variants, but I do not have Windows...); and allegedly the programmer behind that tool, while still offering the old version for free, has moved on to create a video recovery service. The preview mode did not fix my issue, and I wasn't keen in paying for the commercial solution, which may not have worked either...

Dear user000001
Your comment saved me - I repaired my broken mp4 file. Thanks!

The mdat box in a MP4 contains the media payload but it is freeform. It is as good as gibberish on its own. The moov box identifies how many tracks there are, which codecs and their parameters those tracks contain, which portions of the data in the mdat correspond to which tracks, what their timestamps are..etc.
What MP4 repair utilities do, is use the track and codec descriptions from the moov box of the reference file and transpose them to the repair candidate. Then they use heuristics to identify each track's data in the candidate. This relies on the codec of each track sporting some consistent & known signature to locate the start of each packet. The timestamps are however unrecoverable. So, if there's no reference moov or a way to create a similar one, the file is essentially unrecoverable.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


text:
Zoom in and out a video frame panel in Adobe Premiere
In Adobe Premiere, I need sometimes to add some small custom masks. And I need to zoom in the video frame in this case. The only option I found is to manually drug a video panel border.

Are there special hotkeys for these actions (zoom in and zoom out video frame)?

Yes, well not for zooming but for maximizing and restoring the panel. These shortcuts may look different depending on the keyboard layout. On English layouts it's ` for the active frame, which is the frame with the thin blue border drawn around, and Shift+` for the frame under the cursor. The ` character is called acute or backtick.
If you use another keyboard layout and the ` does not work or you want to change the shortcuts, go to Edit menu -> Keyboard Shortcuts... Search for Maximize and you'll get "Maximize or Restore Active Frame" and "Maximize or Restore Frame Under Cursor".
Also, you can set zoom-in/-out shortcuts for the program monitor, but it zooms into the video and doesn't make the panel larger. Those shortcuts are not set by default.

Yes, zoom-in/-out shortcuts for the program monitor is what I was looking for. Thanks!

authors: Артур Гудиев

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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How does Premiere Pro keep markers on audio files even after export?
I opened a project with video and audio, and the audio had markers done in Premiere Pro (right-click on the playhead -> Add Marker).
Then I exported the audio to AIFF. And then I imported the AIFF file into another Premiere Project.
And the Premiere Pro marker was still there.
I'd like to understand how that happened. How was it preserved through export and reimport? Was it kept in the audio file's data, like EXIF data for a photograph?

Markers are part of the XMP standard and are stored in the file. So yes, it's comparable to EXIF. You should notice, that immediately when adding a marker, the file on the disk will be changed, meaning the change date of the file should update. At least that's true on Windows. I don't know what file system a Mac uses and if that's behaving differently.
In the case of AIFF files (and probably any other file), the XMP data section is written at the end of the file. You find the markers in the XML element xmpDM:markers.
An entry for 1 marker in the marker section can look like this:
<rdf:li rdf:parseType="Resource">
   <xmpDM:startTime>839040</xmpDM:startTime>
   <xmpDM:comment>Test Comment</xmpDM:comment>
   <xmpDM:name>Test Name</xmpDM:name>
   <xmpDM:guid>8e5a3759-fe4a-4804-91e1-956c5dfc47f0</xmpDM:guid>
   <xmpDM:cuePointParams>
      <rdf:Seq>
         <rdf:li rdf:parseType="Resource">
            <xmpDM:key>marker_guid</xmpDM:key>
            <xmpDM:value>8e5a3759-fe4a-4804-91e1-956c5dfc47f0</xmpDM:value>
         </rdf:li>
         <rdf:li rdf:parseType="Resource">
            <xmpDM:key>keywordExtDVAv1_90c13ac7-d433-487b-a9bb-da6330736178</xmpDM:key>
            <xmpDM:value>{"color":4292277273,"index":0,"name":"","payload":""}</xmpDM:value>
         </rdf:li>
      </rdf:Seq>
   </xmpDM:cuePointParams>
</rdf:li>

Since the file is mostly binary you may need a special editor that shows you the last part of the file which is human readable text, if you want to see that. On Windows I've used WinMerge. I don't know what can be used on a Mac.
P.S:
This only works with the preference "Write clip markers to XMP" enabled:

Are you saying that the XMP data is written inside the AIFF file? What type of program do I need to look for (Mac user) to be able to read XMP data from an AIFF file?

Yes. You can look for Hex Editors. But chances are slim that you find a good one. Either they crash if the file is too large or just show everything in hex code and cannot interpret the last part as text. And they are awfully ugly. WinMerge is a diff tool which usually compare two files. You could search for similar diff tools and use such to compare an unchanged copy of the audio file with the changed versions, thereby seeing quickly what part is relevant. Maybe there is some kind of XMP viewer tool that would be way more comfortable. But I have no recommendation for that either.

On MacOS, if you select two files in the Finder, you can then right-click and select "Compare Files" from the contextual menu.  I think that's part of the standard OS install, if you don't see it, you might need to install XCode developer tools from the Mac App store, which is free.  It's not the best diff tool in the world, but it's convenient.  XCode also parses XML, so you might want to try it anyway.  Or Microsoft VS Code is also a popular choice.

@Matt I was actually able to parse the XML inside a .AIFF audio file with my usual Hex Editor (Hex Fiend for Mac), it was all the way at the end. And it looked like the markers were in there as well as the software used to record video / audio. Thanks!


text:
Overlay video with picture with transparent parts
In Davinci Resolve, how do I overlay video with picture so that the video can be seen in certain part of the picture?
Here's an example:
Suppose that I have a picture of living room, for example this:

Now I would like to create an effect where the video is playing in that TV. It's simple to cut pixels away in Photoshop to create a transparent part in picture but how do I do it in Davinci Resolve?

In a nutshell, it's the same as you would do in Photoshop.  Resolve has all of the same blending modes as Photoshop does.  In fact, any blending mode is just one of a limited number of ways its mathematically possible to combine one image layer with another.
The main difference between compositing images in Photoshop and Resolve is that in the latter, movement presents additional challenges.  So more accurately, yes Resolve is like Photoshopping an image, but it's like doing it 24 to 60 times every second.
The easiest way to accomplish this depends on your footage.  In the above image, yes, you could cut out the TV screen and plop something into the hole.  But it would probably look bad if that was all you did, and the same is true for Photoshop.  To get a good result in Resolve, think of how you would get a good Result in Photoshop.

You would skew the image you're trying to insert to match the
perspective of the Television's frame.

You would feather the edges of the selection to match the camera's
focus.

You would use an additive blending mode, so that it look like the TV
was emitting light, and you would balance the contribution of the
glare on the front of the TV, depending on how bright you wanted it
to appear.

You might add "spill" as if the TV were adding light to the room
(maybe not in this case, because the room is bright).

But with a moving image, especially if the camera is moving, you also need to "matchmove" or "cornerpin" the image you're inserting, so that it appears locked to the screen.
For the sake of simplicity, lets say that your camera is still and you don't need to track, matchmove, or cornerpin.  If that's the case, then 99% of what you need to do can be accomplished in the inspector panel of Resolve's Edit Page.  There are alternative methods for both the Fusion and Color pages, but the Edit Page is the most straightforward for simple tasks.  The process would go something like this:

Import both pieces of your footage into the media pool (cmd/ctrl-I)

Drag the background image (livingroom scene) onto V1 on your
timeline.  Drag the foreground image onto V2.  Think of the vertical
stack of timeline layers in Resolve like Photoshop's layers.  Like
Photoshop, Resolve "sees" the stack from the top down.

Adjust the size, position, and perspective of the foreground layer to
match the perspective of the TV frame.  In Resolve, select the
foreground "V2" clip, open the inspector panel, and adjust the zoom,
position, rotation, pan, and tilt attributes until your image lines
up.  You can also crop the image a tiny amount, and use the "soft"
slider in lieu of Photoshop's "feathering" controls.

Adjust the composite blend mode in the inspector.  "Add" or "Screen"
are usually good for this type of additive, emissive light.  Adjust
the "opacity" slider to taste.

You can also add effects, similar to Photoshop plugins, by dragging
one from the "effect" tab onto either clip in the timeline.  You
could, for example add a slight glow to V2's clip to help sell the composite.
Controls for these effects will appear in a new tab of the inspector
once you've applied one (the specifics of this tab's placement depend
on which version of Resolve you're using.)


text:
Is it possible to change shortcuts related to playback speed?
Increasing playback speed by 10% increments is achieved by pressing SHIFT + L. Can this shortcut be customized? (I want to make it simpler - pressing a single key as opposed to a combo)

Sure you can do that. Go to the Edit menu -> Keyboard Shortcuts... and search for the action you want to change (alternatively search for the keyboard shortcut itself).
Click the little x on the existing shortcut to remove it. Then click the field and type in the new shortcut. If it doesn't work, click once more, and type again.
The only problem is that many shortcuts are already in use and Premiere is immediately removing the shortcut elsewhere when it was in use, so you might want to click undo after accidentally removing a shortcut. You could use the search bar to see if the key is still free or change several shortcuts to free a key.
At the top you can change the keyboard layout profile. So you can always go back to the defaults at any time, if needed.


text:
How can I generate voice as someone elses voice?
I dont know if its possible but I would like to create voice similar to Gandalf from Lord of the rings. Is there some app or program which can help me? I know that I can use google translator but it is not same as human voice
Sorry if this question was asked before.

We don't do such app/service recommendations here. I doubt there is anything good to imitate voices of specific actors out there, anyway. I think some text-to-speech services offer a small selection of more realistic voices, if that's sufficient for you.

You could learn ho to imitate voices, record yourself and edit it, but you cannot magically turn your voice into someone else's withouth much effort. Maybe https://sound.stackexchange.com/ is more approriate for detailed voice imitation questions.

Just saw this. Nothing good can come of it.  Wondering how OP intends to use it?  Gandalf? Really? https://www.econotimes.com/Deepfake-Voice-Technology-The-Good-The-Bad-The-Future-1601278

I have used Real-time Voice Cloning for this purpose. The quality isn't great, but it works for US accented voices better than UK in my experience (Gandalf = Ian McKellen = English).  Maybe this would be better in Sound Design?


text:
Does ffmpeg concat demuxer update the position of the moov atom if present in each video file?
Years ago I asked this question on: stackoverflow about correct syntax using the ffmpeg Concat demuxer to join mp4 files together. One question I hadn't thought to ask at the time was, when joining mp4s that have been encoded by ffmpeg with -movflags +faststart what happens to each joined file's moov atom? Is there only one now? Is the moov still at the top?
Ex: file1.mp4 and file2.mp4 both encoded with ffmpeg using -movflags +faststart and then are joined together using ffmpeg concat demuxer to create all.mp4
I did some investigative work but I'm not very knowledgeable and wanted a definite answer rather than my own assumption. Using the example above I compared the output for "file1.mp4" using atomic parsley and compared it to the output of "all.mp4" and it appears to me that the .moov atom is not in the "faststart" position.
file1.mp4 output
Atom ftyp @ 0 of size: 32, ends @ 32
Atom moov @ 32 of size: 8067606, ends @ 8067638
     Atom mvhd @ 40 of size: 108, ends @ 148
     Atom trak @ 148 of size: 5898695, ends @ 5898843
         Atom tkhd @ 156 of size: 92, ends @ 248
         Atom edts @ 248 of size: 36, ends @ 284
             Atom elst @ 256 of size: 28, ends @ 284
         Atom mdia @ 284 of size: 5898559, ends @ 5898843
             Atom mdhd @ 292 of size: 32, ends @ 324
             Atom hdlr @ 324 of size: 45, ends @ 369
             Atom minf @ 369 of size: 5898474, ends @ 5898843
                 Atom vmhd @ 377 of size: 20, ends @ 397
                 Atom dinf @ 397 of size: 36, ends @ 433
                     Atom dref @ 405 of size: 28, ends @ 433
                 Atom stbl @ 433 of size: 5898410, ends @ 5898843
                     Atom stsd @ 441 of size: 150, ends @ 591
                         Atom avc1 @ 457 of size: 134, ends @ 591
                             Atom avcC @ 543 of size: 48, ends @ 591
                     Atom stts @ 591 of size: 24, ends @ 615
                     Atom stss @ 615 of size: 5584, ends @ 6199
                     Atom ctts @ 6199 of size: 2502720, ends @ 2508919
                     Atom stsc @ 2508919 of size: 1047220, ends @ 3556139
                     Atom stsz @ 3556139 of size: 1258620, ends @ 4814759
                     Atom stco @ 4814759 of size: 1084084, ends @ 5898843
     Atom trak @ 5898843 of size: 2168697, ends @ 8067540
         Atom tkhd @ 5898851 of size: 92, ends @ 5898943
         Atom edts @ 5898943 of size: 36, ends @ 5898979
             Atom elst @ 5898951 of size: 28, ends @ 5898979
         Atom mdia @ 5898979 of size: 2168561, ends @ 8067540
             Atom mdhd @ 5898987 of size: 32, ends @ 5899019
             Atom hdlr @ 5899019 of size: 45, ends @ 5899064
             Atom minf @ 5899064 of size: 2168476, ends @ 8067540
                 Atom smhd @ 5899072 of size: 16, ends @ 5899088
                 Atom dinf @ 5899088 of size: 36, ends @ 5899124
                     Atom dref @ 5899096 of size: 28, ends @ 5899124
                 Atom stbl @ 5899124 of size: 2168416, ends @ 8067540
                     Atom stsd @ 5899132 of size: 106, ends @ 5899238
                         Atom mp4a @ 5899148 of size: 90, ends @ 5899238
                             Atom esds @ 5899184 of size: 54, ends @ 5899238
                     Atom stts @ 5899238 of size: 32, ends @ 5899270
                     Atom stsc @ 5899270 of size: 40, ends @ 5899310
                     Atom stsz @ 5899310 of size: 1084092, ends @ 6983402
                     Atom stco @ 6983402 of size: 1084084, ends @ 8067486
                     Atom sgpd @ 8067486 of size: 26, ends @ 8067512                     ~
                     Atom sbgp @ 8067512 of size: 28, ends @ 8067540
     Atom udta @ 8067540 of size: 98, ends @ 8067638
         Atom meta @ 8067548 of size: 90, ends @ 8067638
             Atom hdlr @ 8067560 of size: 33, ends @ 8067593
             Atom ilst @ 8067593 of size: 45, ends @ 8067638
                 Atom ©too @ 8067601 of size: 37, ends @ 8067638
                     Atom data @ 8067609 of size: 29, ends @ 8067638
Atom free @ 8067638 of size: 8, ends @ 8067646
Atom mdat @ 8067646 of size: 403164726, ends @ 411232372

all.mp4 output
Atom ftyp @ 0 of size: 32, ends @ 32
Atom free @ 32 of size: 8, ends @ 40
Atom mdat @ 40 of size: 197417544, ends @ 197417584
Atom moov @ 197417584 of size: 5203090, ends @ 202620674
     Atom mvhd @ 197417592 of size: 108, ends @ 197417700
     Atom trak @ 197417700 of size: 3803979, ends @ 201221679
         Atom tkhd @ 197417708 of size: 92, ends @ 197417800
         Atom edts @ 197417800 of size: 48, ends @ 197417848
             Atom elst @ 197417808 of size: 40, ends @ 197417848
         Atom mdia @ 197417848 of size: 3803831, ends @ 201221679
             Atom mdhd @ 197417856 of size: 32, ends @ 197417888
             Atom hdlr @ 197417888 of size: 45, ends @ 197417933
             Atom minf @ 197417933 of size: 3803746, ends @ 201221679
                 Atom vmhd @ 197417941 of size: 20, ends @ 197417961
                 Atom dinf @ 197417961 of size: 36, ends @ 197417997
                     Atom dref @ 197417969 of size: 28, ends @ 197417997
                 Atom stbl @ 197417997 of size: 3803682, ends @ 201221679
                     Atom stsd @ 197418005 of size: 150, ends @ 197418155
                         Atom avc1 @ 197418021 of size: 134, ends @ 197418155
                             Atom avcC @ 197418107 of size: 48, ends @ 197418155
                     Atom stts @ 197418155 of size: 104, ends @ 197418259
                     Atom stss @ 197418259 of size: 3464, ends @ 197421723
                     Atom ctts @ 197421723 of size: 1613944, ends @ 199035667
                     Atom stsc @ 199035667 of size: 675328, ends @ 199710995
                     Atom stsz @ 199710995 of size: 811620, ends @ 200522615
                     Atom stco @ 200522615 of size: 699064, ends @ 201221679
     Atom trak @ 201221679 of size: 1398897, ends @ 202620576
         Atom tkhd @ 201221687 of size: 92, ends @ 201221779
         Atom edts @ 201221779 of size: 36, ends @ 201221815
             Atom elst @ 201221787 of size: 28, ends @ 201221815
         Atom mdia @ 201221815 of size: 1398761, ends @ 202620576
             Atom mdhd @ 201221823 of size: 32, ends @ 201221855
             Atom hdlr @ 201221855 of size: 45, ends @ 201221900
             Atom minf @ 201221900 of size: 1398676, ends @ 202620576
                 Atom smhd @ 201221908 of size: 16, ends @ 201221924
                 Atom dinf @ 201221924 of size: 36, ends @ 201221960
                     Atom dref @ 201221932 of size: 28, ends @ 201221960
                 Atom stbl @ 201221960 of size: 1398616, ends @ 202620576
                     Atom stsd @ 201221968 of size: 106, ends @ 201222074
                         Atom mp4a @ 201221984 of size: 90, ends @ 201222074
                             Atom esds @ 201222020 of size: 54, ends @ 201222074
                     Atom stts @ 201222074 of size: 112, ends @ 201222186
                     Atom stsc @ 201222186 of size: 160, ends @ 201222346
                     Atom stsz @ 201222346 of size: 699112, ends @ 201921458
                     Atom stco @ 201921458 of size: 699064, ends @ 202620522
                     Atom sgpd @ 202620522 of size: 26, ends @ 202620548                         ~
                     Atom sbgp @ 202620548 of size: 28, ends @ 202620576
     Atom udta @ 202620576 of size: 98, ends @ 202620674
         Atom meta @ 202620584 of size: 90, ends @ 202620674
             Atom hdlr @ 202620596 of size: 33, ends @ 202620629
             Atom ilst @ 202620629 of size: 45, ends @ 202620674
                 Atom ©too @ 202620637 of size: 37, ends @ 202620674
                     Atom data @ 202620645 of size: 29, ends @ 202620674

Can anyone with moov knowledge prove my assumption right or wrong? If I'm right and ffmpeg concat does not automatically assume to move the moov atom to the top should I change my approach and add -movflags +faststart to the concat demuxer command?

The metadata from an input file in any ffmpeg operation is used to interpret and handle the media data in that file. That metadata is not naively copied over, wholesale or piecemeal*. FFmpeg will always generate new metadata based on the specific set of media data received when generating the output. Since the output of concat operation is one file, it will have one moov box. If you want the concat output file to have moov box up front, you will have to add -movflags +faststart.
*exception is string tags such as ID3 or timecode data.

Thanks @Gyan I appreciate the response. This is good insight to know.


text:
Does recording desktop audio reduce quality?
If I record audio (say, a 320 kbps mp3) that's playing through my desktop audio (in, for example, Audacity with loopback, or OBS) is the quality going to be reduced if I compare the recording to the original file? For the sake of this hypothetical lets assume the compression level of the rendered recording is also 320kbps mp3.

Does the act of recording the audio in this manner inherently reduce the quality? (regardless of compression method e.g. .wav to .wav)
Does reencoding/compressing the audio from 320kbps mp3 to 320kbps mp3 result in a measurable quality loss?

Audacity would grab the digital data for recording in this case and since it uses a lossless format for recording you would not lose any information. I don't know about OBS but it would be surprising if they do things differently.

There will be a very slight loss of quality with 320 kbps mp3s. I doubt any human would hear a difference, though. This may become noticable at some point if you keep re-encoding the file again and again, for example for editing the audio later. If you use a low quality source, say 128 kbps mp3, the degradation will be much more pronounced.


text:
Keep the current position in the center of the timeline in Adobe Premiere
In Adobe Premiere, the current position in the Timeline panel often moves to the right end (while playing) so I can't see what is going to play next.

Is there any hotkey to fast forward the timeline (not the current position) so the current position will be at the center. Or maybe there is an option to keep the current position always in the middle of the timeline?

Hold the Shift-Key pressed and move your mouse wheel to scroll the timeline horizontally. This works when not playing as well as when playing but only if the timeline is not auto-scrolling.
If you want to keep the playhead centered, go to Edit-Menu -> Preferences -> Timeline and select "Smooth Scroll" where it says "Timeline Playback Auto-Scrolling", see also the screenshot:
One more tip: the thin blue line marking the current position is called the playhead.

Ok, thanks! I guess, there is no specific hotkey to center the playhead.
But "Smooth Scroll" solves the problem. And thanks for the tip!

authors: Артур Гудиев


text:
How do I capture a noiseprint in Vegas Pro with the Noise Reduction plugin?
When I go to capture a noiseprint, I don't get a noiseprint or the noiseprint appears around -120 dB as a flat line.

Add Event FX (not Track FX) plugin Noise Reduction by clicking on the "fx" symbol and selecting Noise Reduction.

Select a region of noise in the audio.

Select "Capture noiseprint" in the effects window.

Press play in the Preview window.

Optionally, save the captured noiseprint as a preset.


text:
How do I automate the export different layers combinations ( turning on and off ) in After Effects
I have a comp that has various layers that I would like to toggle on and off in combination. Lets say I would like to turn on and off layer to create 60 distinct combinations. I do this by hand, add to the render queue one at a time and then export, but this is a real pain.  Is there any way in after effects ( perhaps even through scripting ) to create something like "layers comps" and "layer comps to files".

Templater can do this.
https://aescripts.com/templater/
You feed it a load of google (or excel or CSV) tables, with specified values, and it can churn through a load of files to export different comps with different arrangements.


text:
Health issues concerning video lights
For a small home studio lighting setup, I have concluded that softboxes with clf bulbs or LED panels would be adequate.
But clf bulbs contain mercury, and even though it is a small amount, accidents tent to happen.
On the other hand, I have read that LED lights are bad for eyes. I don't conclude related links because I think that you all have heard of that. If so, does the quality of the bulb has to do something with that? That is because I intend to buy some Chinese ones, I can't afford anything else.
Are all these issues real or myth? Any thoughts or alternative suggestions would be appreciated.
P.S. I am interested in 5600K bulbs.

Mercury is enclosed within the bulb, and does not pose any threat to the user, unless the bulb breaks. In such case the amount of mercury released is still rather small, though it certainly makes sure to clean it properly. More important is safe disposal of the bulbs. See e.g. this article: https://earth911.com/home-garden/broken-cfl-clean-up/
LEDs can be tiring for eyes due to flickering. LEDs for photography should not flicker much, otherwise they will produce visible artifacts.


text:
What cable type (TRS or TRRS) is appropriate for connecting my Zoom H5 to my Sony A6400?
So, I have a Sony A6400 camera that I want to connect directly to my Zoom H5 audio recorder in order to record my sound directly onto the camera video without bothering to sync it up in my post production software.
Now for the connection required between my H5 to my A6400 does it need to be a TRS cable or a TRRS cable? Second question is what is best for quality- OFC or OCC cable or does it even matter really?

Use a TRS cable. Make sure you reduce the line-out level in your Zoom H5, otherwise the audio in your camera will peak all the time.
The quality/purity of the copper in the cable is irrevelant. This OFC vs. OCC is just marketing-blah-blah. Apparently no manufacturer has been able to prove any discernible difference.
A real problem is that these 3.5mm jacks and cables aren't durable in the field. They just break too easily.


text:
HTML tags in SRT files produced by ffmpeg
What I do:
$ ffmpeg -i a.mkv -c:s srt b.srt

The resulting file contains HTML tags, is there a way to avoid that?
On a side note, where can I find the list of... what do they call it... encoders? I simply tried srt for the name and it worked.

Instead of srt try to use text:
$ ffmpeg -i a.mkv -c:s text b.srt

(source)
For a list of all codecs use:
ffmpeg -encoders

You can check the documentation for more options.

Well, the documentation is apparently rather incomplete. Some things can only be learned from the code. Like, what's the difference between the srt encoders.


text:
Outline/stroke around transparent-background PNG in After Effects
I was wondering if there is a way to expand a fill, outset a shadow or something, around a PNG with transparent background.
Right now I am using Fill + Simple Choker to expand the contour + CC Composite to bring it to the bottom, and sort of works, but I can expand the outline only a few pixels, like less than 100. Ideally, I'd like to animate it, so I can't just add the outline in Photoshop!
Is there an alternative way to do that? Thank you in advance.

Try using Layer--> Auto-trace to trace around the alpha. It will generate a mask which you can then expand.
Or you could use a Layer Style to get a similar effect with a drop shadow or glow effect.


text:
Life-size building floor plan
I need to develop a life-size building plan, I will prepare a floor plan from any Autocad software and later send it to 6 different projectors to get a Life-size building floor plan so that the end customers can have a walkthrough of their house. it will be a 2D effect only.
Which software can help me send my floor plan to 6 projectors?
How will this entire thing work. Please share some views

You need to use video projection mapping software, and 3D rendering software. Mad Mapper is a well known projection mapping application.
Blender or Cinema4D would do the 3D rendering.

Thanks for your inputs. I would like to know whether the projection mapping application also helps in point correction and overlapping intensity adjustments. I would like to know more about the software and its features used to develop the life-size building floor plan as shown in this URL https://www.youtube.com/watch?v=aejn1GERcYY

There's one called Resolume that's used for concerts and live events.  Part of the software is for projection mapping images to unusually-shaped displays and projection screens, but it also includes a lot of features for timing and controlling lights via DMX, which you might not need.  https://resolume.com/software


text:
Vector graphics from Photoshop to After Effects
I want to animate an old WW1 military map in After Effects. I drew this map in vector using the Illustrator and now I need to give it a vintage look by overlaying various textures and overprints. For this kind of work, Photoshop is the ideal solution.
I'm wondering if I export my project from Illustrator to Photoshop as smart object, make all the necessary changes, and then export from Photoshop to After Effects, will I be able to work with vector graphics there?
Or is it better to export from the Illustrator directly to After Effects and try to stylize the image already there?
Thanks for the advice.

I would keep the .ai files in Illustrator. Then import them to After Effects and do any photoshop-style layering in there, unless there's anything really complex that AE can't do. Otherwise you're adding an extra step that you possibly don't need.  Each time you update the changes in Illustrator, you should see them reflected in AE after a few seconds.  Using something like Overlord can allow you to manipulate shapes in after effect directly.

If the effects and textures you add in Photoshop are raster (pixel) based, then you'll lose the advantages of vectors in the process. I'd probably do the stylisation in AE, but if you're more familiar with PS do it there, just use a high enough resolution that you won't be giving yourself headaches in AE.


text:
VHS and capture: what is the real aspect ratio?
I have captured a vhs with this script under Linux
#!/bin/sh

videodevice="/dev/video0"
alsadevice="hw:2,0"

v4l2-ctl -d /dev/video0 --set-ctrl mute=0

v4l2-ctl -d /dev/video0 -i 1

v4l2-ctl -d /dev/video0 --set-standard=PAL

gst-launch-1.0 -q v4l2src device="$videodevice" do-timestamp=true norm="PAL" pixel-aspect-ratio=1 \
    ! video/x-raw,format=YUY2,framerate=25/1,width=720,height=576 \
    ! queue max-size-buffers=0 max-size-time=0 max-size-bytes=0 \
    ! mux. \
  alsasrc device="$alsadevice" do-timestamp=true \
    ! audio/x-raw,format=S16LE,rate=48000,channels=2 \
    ! queue \
  max-size-buffers=0 max-size-time=0 max-size-bytes=0 \
    ! mux. matroskamux name=mux \
    ! queue max-size-buffers=0 max-size-time=0 max-size-bytes=0 \
    ! filesink location=vhs.mkv

The final result is a raw avi, which I had to crop and resize to correct Aspect Ratio.
The mediainfo program said is 5:4
mediainfo vhs.mkv |grep -i aspect
Display aspect ratio                     : 5:4

But as I know the vhs is an old technology and in their times(70-80-90) the standard was 4:3
I ask this because to determine the AR I usually do this
a)make a screenshot with mplayer
b)open with gimp, select rectangle and I read the a/r (1.7777,1.6666,1.3333) in the bottom of program

the screenshot result different and return different a/r if I set with mplayer the a/r
mplayer -vf rectangle,screenshot -aspect 5:4 vhs.mkv
mplayer -vf rectangle,screenshot -aspect 4:3 vhs.mkv

In your opinion I have to use 4/3 or 5/4?

I have tested a 4:3 vhs, and using 5:4 a/r making screenshot report bad final a/r(1:22)
mplayer -aspect 5:4 -vf screenshot

using 4:3 a/r report in screenshot the correct ar(1:31:1)
mplayer -aspect 4:3 -vf screenshot

So I think the correct answer is 4:3.

PAL and NTSC both use non-square pixels, so the physical image width / physical image height ≠ number of pixels wide/ number of pixels high.  https://en.wikipedia.org/wiki/Pixel_aspect_ratio


text:
Animate variable inside expression
In After Effects, I created a shape layer, added a path to that, edited the expression of it to contain
var path = thisProperty;
var cx = 100;
var cy = 200;
var r1 = 300;
var ratio =  20;
var quality = 30;
var closedPath = true;
var allPoints = new Array();

for (var a = 0; a < 360; a++) {
    var theta = degreesToRadians(a);
    x0 = Math.cos(theta);
    x = cx + r1 * x0;
    y = cy + 0.75 * r1 * (Math.sin(theta) - Math.sqrt(Math.abs(x0)));
    allPoints.push([x,y]);
}
path.createPath(allPoints, [], [], closedPath);

and added a stroke and a fill to the shape layer and set the width of the stroke to 10 and the color of the fill to light red. I got this shape as a result.

Now, I want to animate the end point of that stroke, you may see that I am looping the variable a from 0 to 360. That 360 value represents the end angle of the shape and I would like to have it animated to make an animation that "draws" the heart.
How do I animate the end value?
Is there a way to add a "dummy effect" so I can use it like
var a_max = effect("dummy")("endpoint")

Press the triangle marked "Add" next to the Contents of your shape layer.
Add a "trim path"
Add a keyframe to the "End" parameter of 0%.
Move along your timeline.
Add another keyframe of 100%.

Your path will draw on.
You probably don't want to fill it until it is drawn.

Tom's answer is a good way to do it, but if you're interested, to do it only in the expression, just add a couple of lines at the start like
myDuration = 5; // the duration of the animation in seconds
let completion = Math.min(time/myduration, 1)

and then in the for loop, substitute "360" with 360 * completion
for (var a = 0; a < (360 * completion); a++) {


text:
Premiere CC: How to select/drag clip in program window?
Running Premiere Pro 2018 on Windows. Previously, I could animate the scale and position of the clip in the program window by clicking to select it and using handles to scale, or drag it around within the program monitor. This would create keyframes and update the scale and position settings. It made it very easy to do "pan and scan" type zooms and rolls.  I'm not sure if I was using an earlier version then.
On my current project, I can't select the clip in the Program monitor. I click it with the selection tool and never see handles on the image. Selecting it in the Timeline doesn't do anything either. I can add key frames and adjust position numerically in the Effects Monitor panel, but I'd like to use the mouse in some cases. Does anybody know what I'm missing?

To answer my own question, I found a solution by clicking around finally. In the Effects Control panel, clicking the Motion property label causes handles to appear on the video in the Program Monitor. Then, with the Selection tool, you can drag the image to reposition it, or drag a corner handle to scale it. I believe I was able to do this in earlier versions without first selecting the Motion label, but at least I can do what I want easily now.


text:
How to compare the illuminance of similar light fixtures in Lux given at different distances?
I am trying to compare the brightness of these two fixtures:

Godox LEDP260C: 2050 Lux @ 0.5m

Godox LED1000Bi II: 2200 Lux @ 1m

(Both at 3300K).
How do I effectively compare these two values? The light sources are similar in shape and size (30x20cm for the first and 40x40cm for the second).
How. Do I go about comparing these two? What about cases where the size and distribution of light is not so similar?

You could do some back of the envelope calculations, if they're both the same shape and the LEDs in them have similar lenses etc., the beam will be similar, so the falloff will be similar.
Given that the area illuminated at 1m is 4 times the area illuminated at 0.5m (area of a segment of a sphere is proportional to the radius squared, so twice the distance squared is 4 times the area), the intensity of the first is going to be roughly ¼ that of the second. Which figures, going by the model number: the first is probably meant to be "equivalent" (these figures are always rubbery) to a 260W incandescent light and the second to a 1000W light, so roughly 4 times as powerful.
You could also compare the wattage to see exactly how much power each one is.
In cases where they're not similar size and distribution (BTW the first panel is less than half of the area of the second, so in no way would I say they're similar in size), then you're comparing apples with oranges. Different lights do different jobs.
TBH With cheapo lights like that I'd actually be more concerned about how good the colour was.

This is helpful, but does not completely solve my problem. You seem to be able to estimate the tunsgen equivalent of the lights I listed. I am looking for some way to do that too. Ultimately, I need some starting point so that I can know what I'm dealing with, even if very approximate. Thanks!

I'm going off the model number. Many LED manufacturers base their lights on tungsten equivalents, in order to help users switch. They always inflate the values though, so use caution. Find out how much power (will be given in Watts) the LEDs use and that will give you an idea of their output. Rule of thumb is multiply it by 4 to get the equivalent for a tungsten globe. So a 100W LED is about the same as a 400W tungsten.

Thanks. So in this case, the P260C consumes 30W, and the 1000Bi II consumes 70W. So although the model names might hint that they'd be ~300W and ~1000W equivalents, the truth is they could very well be closer to 120W and 280W respectively. From experience, I would say that the P260C is somewhere in-between those two values.

Some lighting manufacturers publish photometric data of their lights as .ies files. This is usually for architectural applications, but you could look for lights with similar specifications, and compare their .ies profiles in a 3D package that supports PBR.


text:
How to move an (overlayed) image across a video in ffmpeg?
moving crop works for video, but I could not make it work for a (jpg) image. How to move an image in the video using ffmpeg?
Here is my try that does not work ($TST is a .jpg):
ffmpeg -ss 30 -i main.mkv -i $TST -filter_complex \
    "color=c=${CG}:size=1380x1080,[0]overlay,\
    chromakey=${CG}:.031:0.025,despill[a];[1]crop=w=1920:h=1080:x='t*in_w/3':y='t*in_h/3'[b];[b][a]overlay" \
    -c:v ffv1 -map 0:a -c:a copy -t 1s tstres.mkv

An image is treated by ffmpeg as video stream with one frame. For a crop animation to be effected, you need a stream of frames.
Add loop before the image input: -loop 1 -i $TST. Normally, you would be advised to limit the duration by also adding -t, but since you limit duration on the output, it is not necessary here.


text:
How to convert video to NTSC (so it can be burned to a DVD) without losing quality?
I have a 1080p mp4 video, and I want to burn a DVD from it. It must be 'mastered' as a DVD, so it can be played back on an older DVD player (i.e. it can't be a data DVD). For the tool that I'm using to make the DVD, I need to convert the video to the correct format with the correct codec before burning. I am in America, so I know that standard is NTSC. I tried converting my video with:
ffmpeg -i input.mp4 -target ntsc-dvd output.mpg

but the result was quite fuzzy and low-res. I did some research and it seems like NTSC only supports up to 720p, but as I understand it, NTSC is still the standard today, and there are HD DVDs. So is there a a way to convert my video to NTSC so that I can burn a DVD without losing resolution?
Please forgive me if this is an ignorant question, and correct me about any false assumptions.

DVD does not support 720p. It’s only supports 480p/i.
HD DVD was a failed competitor to Blu-ray. Standard DVD players are not forward compatible.


text:
How to use the frame at 5s and replace all frames before it using ffmpeg?
I have a video file a.flv. I want to use ffmepg to edit it. As I understand, each second of the video is a series of frames. What I want is to take the first frame of the fifth second and replace all frames before it. So the result video has exactly the same video data from the beginning to the first frame of the fifth second. Is it possible to do this using ffmpeg?

You can use a combination of the trim and tpad filters for this.
ffmpeg -i in.flv -vf "trim=4,setpts=PTS-STARTPTS,tpad=start_duration=4:start_mode=clone" -c:v libx264 -c:a copy out.flv

Thank you! It works.


text:
What should I learn in order to understand ffmpeg?
I'm able use some basic ffmpeg commands to process videos, but I never fully understood them. There are too may terminologies in ffmpeg's documentation that I don't understand. What should I learn so that I can read ffmpeg's document by myself? I want to learn the video audio structure and other basic knowledge.

This resource should help you with what you need to know https://opensource.com/article/17/6/ffmpeg-convert-media-file-formats


text:
Find out video's resolution & duration
Any easy way to find out a video's resolution & duration?
I know one way is to parse the ffprobe's output. But,

I don't know how consistent the output is among different video files.
and most importantly, I hope to avoid such parsing entirely.

I've tried

ffprobe -print_format json ...
ffprobe -print_format compact ...

But neither seems to be what they are supposed to be

-print_format format  set the output printing format (available formats are: default, compact, csv, flat, ini, json, xml)

Use MediaInfo?
About:
https://mediaarea.net/en/MediaInfo
//
Downloads:
https://mediaarea.net/en/MediaInfo/Download
But you need to install it.
On Windows (haven't tested on mac), it shows up as option on rightclick


text:
ffplay -- suppress configuration information on startup
Is there a way to suppress configuration information when starting ffplay? I know I could redirect to /dev/null but I don't want to lose stderr or stdout. Thanks!

The intended way to do this is to add -hide_banner. This way, logging is still visible.


text:
Platform used for creating following video
This may be a subjective question, but I'm not sure where else to ask, so apologies in advance!
I want to know the name of the software being used to make such purple, pink blocks as shown in the video below

It is most likely simply a presentation program. The best known is PowerPoint, but you can get one free using Libre Office https://www.libreoffice.org/ or some web-based like google docs.
Libre Office has two programs that can be suitable. Impress and Draw.

Thanks Rafael I COULD DO THAT IN Google Sheets

I would do it in Adobe illustrator as it helps with lining up things


text:
How to hold the last frame when using ffmpeg
I'm cutting/converting some videos with ffmpeg.  What I'd really like is to be able to have the output hold the last frame for a few seconds (with silence for audio).  Is such a thing possible?  Or will I have to somehow get the last frame and make a new video from that?

The currently accepted answer is from 2014. The more recently added tpad filter lets you do this more easily.
ffmpeg -i in.mp4 -vf tpad=stop_mode=clone:stop_duration=2 out.mp4

This solution can be slow since it re-encodes the video. This solution is much faster: https://video.stackexchange.com/questions/10825/how-to-hold-the-last-frame-when-using-ffmpeg/36571#36571

One method is to use the overlay video filter. Assuming your video is 640x480, 30 seconds duration, 25 frame rate:
ffmpeg -f lavfi -i nullsrc=s=640x480:d=35:r=25 -i video.mp4 -i audio.wav -filter_complex \
"[0:v][1:v]overlay[video]" -map "[video]" -map 2:a -codec:a copy -shortest output.mkv

I set the duration of the nullsrc source filter to be 5 seconds longer than input.mkv.
The default behavior of overlay is to repeat the last frame of the overlaid source. See the eof_action option for other behaviors.
The audio in this example is being stream copied (re-muxed) instead of being re-encoded.
The downside is that this examples requires re-encoding since a filter is being used, but it may be simpler than other methods since it is just one command.

That sounds great - but can I do it if I'm also replacing the audio stream with a wav file?  Also, do I need to know the size of the source video?

@xorsyst Yes, you can replace the audio. I updated the example. Yes, this method requires that you know the frame size, duration, and frame rate of the source video, but all of these variables can be scripted. See FFprobe Tips.

This solution is much faster because it does not require re-encoding.
If there already is an existing audio stream:
ffmpeg -i in.mp4 -vcodec copy -af apad -t 60 out.mp4

If there is NO existing audio stream:
ffmpeg -i in.mp4 -f lavfi -i anullsrc -vcodec copy -af apad -t 60 out.mp4

Note that the -t 60 refers to the length in seconds of the final output, not the seconds to extend it by.

The reason this works is because when the video and audio are different lengths, ffmpeg will extend the shorter stream to match the longer one by default (unless you use the -shortest option).

(credit Gyan)

Great solution - Now if I could only also apply a fade-out to the audio this would be perfect.

I believe the answer to your question is "yes".  I'm not super familiar with FFMPEG, but the easiest way I can see to accomplish your goal is to first extract the last frame to an image, make a video of a few seconds and then run an encode that concatenates the main video and your newly created video in one pass.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
Using ffmpeg, can I remove the color from an area of the video
a TV station I watch has a very distracting logo, which is a semi transparent red square.

I can cover up the logo with the delogo filter like this: (Alas this introduces new distractions.)
ffmpeg -y -i input.TS -vf delogo=x=79:y=36:w=57:h=57:show=0 -t 120 -vcodec h264_qsv -b:v  12300k output.ts

Is there a way to use ffmpeg to remove only the color from the area of the logo?
Because if it was just gray, it wouldn't be that distracting and taking out the color would not introduce flickering artefacts.

I found one solution in cropping the video, turning it into black and white and then putting this as an overlay on itself.
ffmpeg -y -i "input.ts" -filter_complex "[0] crop=57:57:79:39 [cr];[cr] hue=s=0 [cr2];[0][cr2] overlay=79:39" -map "[cr2]" -vcodec h264_qsv -b:v  12300k output.ts

This is the standard way to do it.


text:
Is there a way to use nlmeans_opencl filter with a 10 bits source?
So far I have only managed to run nlmeans_opencl filter with the following settings:
ffmpeg -init_hw_device opencl=gpu:0.0 -filter_hw_device gpu -i 10bit_input.ts \
       -vf "hwupload,nlmeans_opencl,hwdownload,format=yuv420p" -an output.mp4

Pretty much every other pixel format I set to format= fails one way or another. For example
My source is yuv420p10le, so that is my first choice, but I get this error:
[hwdownload @ 0x55ab32e60c40] Invalid output format yuv420p10le for hwframe download
[Parsed_hwdownload_2 @ 0x55ab32e61c80] Failed to configure output pad on Parsed_hwdownload_2
Error reinitializing filters!
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #0:0
Conversion failed!

With yuv420p16le:
[Parsed_nlmeans_opencl_1 @ 0x563d97d93600] input format yuv420p16le not supported
Error while filtering: Invalid argument
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #0:0
Conversion failed!

With no format=... at all:
[hwdownload @ 0x5610a4653380] Invalid output format gray for hwframe download.
[Parsed_hwdownload_2 @ 0x5610a472a400] Failed to configure output pad on Parsed_hwdownload_2
Error reinitializing filters!
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #0:0
Conversion failed!

So, is there any way to make this work, without dropping component precision to 8 bits?

No, the nlmeans_opencl filter supports yuv420p, yuv444p and gbrp, all 8-bit planar formats.


text:
Benefits of component/RGB connector (vs. S-video or composite) for VHS capture?
I know it's 2020 but I still have a few VHS tapes to digitise.
I do not expect the picture quality to be necessarily good enough to worry about this question. Still, I would hate to lose any tiny little bit of the quality just because I choose my analog gear inferior to what I could have chosen. This is a one-off task and I want to be sure I could not do it any better.
That said, I do not have any VCR for this task yet. I am just about to figure out what to look for.
I have done a little bit of research to find out what analog connectors are there and which ones are capable of carrying which quality. It looks like component and RGB standards/connectors are the best ones (as opposed to S-video and composite).
Assuming that the VHS tape record is still very good (no big chances, but let's assume), would the picture quality benefit from component/RGB connectors at all? Should I be looking for a VCR that has these outputs?

Component Y/Pb/Pr is better than both S-video and composite.  It supports higher resolution, and progressive scan (480p,720p,1080p).  The Y is luminance and sync signaling, the Pb is blue minus, and the Pr is red minus.  Since its progressive, it uses more bandwidth than the former's.
It's easy to get "component" mixed up for "composite"/"rca".  Component is the Red/Blue/Green cables, composite (or RCA) is the Yellow/Red/White cables.
The S-video and composite were made for standard definition video, which is lower resolution interlaced, as opposed to progressive.  interlaced video has less bandwidth needs.
Normally you would use Component when you have it available over composite and s-video alternatives, but don't yet have HDMI capabilities.
If you can use HDMI, it is better than component, since HDMI is digital, component is not.
VCR's
The goodwill I found is one good source for VCR's.  The Time-sync ones, which you need, are about $400.  Too expensive, when you can get a scaler that has the same frame correction features in it on evil bay for cheaper.  I got one used for $45 (Extron System 7SC, uses Composite, up to 1080p).  The VCR isn't as important as its head is in good alignment (take the cover off and adjust it if not) and VCR has more than a few decent heads on it.
Logically, if you can snatch a good deal on a VCR that has component, then make sure your scaler (or cap card if not using one) has component input.  Scaler's with HDMI aren't really useful for VCR capture IMO.   Im also not sure the component ones are in fact either, since its possible that somehow they have upconverted the signal to make it component, which you can just eliminate, and run it straight into your scaler with svideo or composite.
Out of the scaler it can be scaled up 720p/1080p for raw capture.  So if your capture card has component in, then make sure the scaler has component out.  I'm still a bit yellow in the area if the RGBHV on the back of my scaler can be converted to Y/Pb/Pr easily or not, im not sure.  Im testing instead using composite out of scaler, to composite in to USB capture.  The results are maybe more low light detail than the S-video signal, so it has its benefits.
Scaler
Look for one that takes care of the frame corrections for you, so that you wont have sync issues, when you capture (VirtualDub/HuffYUV I assume?)

https://www.extron.com/article/syst7sc32pulldown
I see this one on evilbay now for $50, https://www.extron.com/product/vsc200 has an S-video output also, which i needed, for my capture card to test over composite, although I'm not sure capturing from S-video is all its chalked up to me, for this purpose.  (not sure about the outputs on this one though)
This one looks decent, has svideo https://www.ebay.com/itm/Extron-IN1508-Video-Converter-Scaling-Switcher/124668934942

I got my stuff dialed in.  ended up going out of Toshiba w614 vcr yellow composite ->  extron 7sc via bnc adapter in, set scaler to 480p 60hz output, then VGA (RGB) out -> capture card via VGA-DVI adapter.  I purchased a Datapath Vision RGB E1, which is pcie4(without backing plate yes), DVI (non digital) in. perfect for RGB capture from the upscaled extron RGB output.   You dont really want to upscale in vdub anyway, let your hardware do it on playback.  large devices, e.g. 4k tv, can upscale it from there.   I still have some capture timing issues, but they dont seem vcr frame related now.


text:
Essential Graphics - Media Replacement issue
I was trying to improve some of my work templates using Essential Graphics, which I absolutely love, for the first time I'm adding the media replacement function to it but it doesn't seem to work.
I've tried images, videos and an actual AE placeholder but it just doesn't seem to accept any of my assets.
Check this tutorial at 05:30 where she successfully achieves what I'm trying to do.
I'm wondering if anyone else has encountered the same issue, I'm probably doing something wrong but I don't seem to see where.

Even though Essential Graphics have been available for a few years now, Replace Media is available around After Effects v18.0, be sure to update your app.


text:
Can't Minimize Video Track Timeline Zoom Automation
This is a simple problem that is driving me crazy. I must have accidentally hit some button that made the track height expand to show zoom automation data in the timeline. It looks like this.

Please show me how to make this disappear.
I am using Davinci Resolve 17 on Windows 10.

The two white squares to the right of the clip name in your image - those will close the curve and keyframe viewers, respectively.


text:
How to record the voices of three people in a room?
We are planning to produce a Youtube channel, in which we interview one professor and one student at the same time, and we have very little experience with sound. A typical situation would be to have three people talking (the prof, the student, the interviewer), and we are wondering what would be a good compromise between budget and quality for recording the audio.
Lav mics seem to be the best option, but since we need three of them it seems expensive. Right? What about having a single shotgun carried by one of us over the scene? Could that work? I assume the person in question would be monitoring the sound to make sure that the mic is at the right position.
We are also planning to invest into a modest on-camera mic just for safety, in case something goes wrong with the other setup during the shootings. Any further advice?

Save the money for the on-camera mic, it is by far the worst option. Other options include:

lapel or lavalier mics. Wireless lav mics are as you say expensive, but wired lav mics might be the cheapest option. You'll need something that can take 3 inputs, either a multitrack recorder, or a simple mixer to mix it to stereo (I'd mix the two subjects into one channel and the interviewer into the other).

If you use a shotgun you can get excellent sound quality, but you'll need a boom and a boom swinger to make sure that the person talking is on-mic. For an unscripted interview with three people this is quite a tall order. If you don't have someone who can do the job of boom swinger, or if your subjects interrupt or talk over each other this is not recommended.

a surface mic or an omnidirectional mic in the center of the speakers. This won't be as good as three lapel mics, because it will be further away from all of them, and will pick up more room ambience and bg noise. This is probably be the cheapest option, but the second worst (the worst being an on-camera mic).

Thanks, we actually convinced our budget people to invest in three wireless Rode lav mics, so I think we chose the best option! And indeed we dropped the on-camera mic.


text:
Can I use ffmpeg to encode a video for Camtasia import?
I'm using ffmpeg to create screencasts.  The command looks like this:
ffmpeg -f x11grab -framerate 30 \
    $(xwininfo | gawk 'match($0, /-geometry ([0-9]+x[0-9]+).([0-9]+).([0-9]+)/, a)\
      { print "-video_size " a[1] " -i +" a[2] "," a[3] }') \
    screencast$(date +%H%M%S).mp4

When I import those into Camtasia for editing, I get a video of the correct dimensions, but it shows only blackness.  I've found that I can make the import work if I re-encode the screencasts with handbrake.
HandBrakeCLI -i screencast101253.mp4 -o screencast101253.m4v

This is what ffprobe says this about the videos that handbrake creates:
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'screencast101253.m4v':
  Metadata:
    major_brand     : mp42
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    creation_time   : 2020-12-04T17:54:49.000000Z
    title           : screencast102753
    encoder         : HandBrake 1.2.2 2019022400
  Duration: 00:01:43.93, start: 0.000000, bitrate: 81 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 1256x1080 [SAR 270:347 DAR 314:347], 77 kb/s, 30 fps, 30 tbr, 90k tbn, 180k tbc (default)
    Metadata:
      creation_time   : 2020-12-04T17:54:49.000000Z
      handler_name    : VideoHandler

My question is: how can I change the ffmpeg command so that it produces a Camtasia-compatible video in the first place--so that I don't have to wait on handbrake?

Need to see ffprobe for the ffmpeg created file, but probably as simple as adding -pix_fmt yuv420p

@Gyan is correct. add
-pix_fmt yuv420p
I was in the exact situation @MatrixManAtYrService described and the video imported into Camtasia Studio correctly after converting with -pix_fmt yuv420p


text:
How to change timeline scale in Davinci Resolve Fusion page?
I am watching a tutorial about creating an animated title. The instructor shows his time line as A, however, mine is shown as B.
How to change from B to A? I have searched for this but I could not find the proper settings on my installed Davinci Resolve 17 (the latest update, free version).

Why is mine negative?

Not sure, but if I had to guess, I'd say that Fusion is showing a point in time that's a few minutes before the clip's boundaries in Resolve.

You can change the preview scale using the numbers below the transport controls. When fusion clips come in from Resolve, Resolve determines the in and out points, based on where the clip sits in your timeline.  So changing the numbers to match a tutorial you’re following is probably not a good idea unless you’re using identical media, and have identical Resolve timelines.


text:
ffmpeg: How to cut 2 parts of a Video an Join them together in specific order
I have a vídeo where I want to cut 2 parts and join them together but I want to put a part that happens at a later time first...
For example cut seconds 23-30 and 45-50 and put the part with seconds 45-50 first.
I used this:
ffmpeg -i input.mp4 -vf "select='between(t,45,50)+between(t,23,30)',scale=720:-1" "output.avi"

But even thoug I put the 45-50 part first in the command the output.avi plays the 23-30 part first in the output.avi video.
How would I join this 2 videos and have the later part played first, I also tried it with filter_complex but I also have to scale the video and it looks like filter_complex and vf can't be used together.
If possible I want to use only 1 reencoding to not loose much quality. Thanks in advance.

Here's the thing about modern video—most formats are actually designed presuming a varying frame rate. We like to think of them like digital filmstrips, but that model rarely works when we're streaming over a network or capturing from many kinds of devices. So, every frame has what's called a Presentation Time Stamp, or PTS.
The problem here is that, while you do indeed concatenate in that order, the PTS for each frame never changes. You can actually manually set the PTS of a frame with the setpts filter, which is definitely something to look into as panning video can get much more complicated than this, and it's deliciously flexible; but may require some reading to understand all of the parameters.
The fields you'll need to know are PTS, which is the presentation timestamp before the filter is run; STARTPTS, which is the presentation timestamp of the first frame rendered, and TB, which stands for Time Base and is basically the ratio between a PTS "tick" and a second; so if you know that your first clip is going to be five seconds long, and you want your second clip to start immediately afterward, you will want to add 5.0/TB to your new PTS.
So, I suggest (PTS-STARTPTS)+(5/TB) for your second clip; but this isn't the only way to determine it and feel free to adjust it if the result doesn't feel right to you.
We're going to use a complex filter here, as we're splitting our stream into two separate streams and concatenating them at the end. (Complex streams actually aren't all that bad, but do take a little getting used to.) One of the big differences with a complex filter is that you generally start each command by specifying a stream for it to use, and end each command specifying a new stream to write to, both in square brackets. When we begin with [0:v], that means to take the first input (input number zero from file input.mp4) and grab its video stream. What comes at the end can be used to identify it later when you want to filter it again.
Lastly, it helps to use the -map tag to tell FFmpeg which stream it is writing from. It's critical, as if FFmpeg wasn't aware of which one to use you could end up with literally any stream or combination thereof in your file; and an invocation can take a while to complete.
Your final command:
ffmpeg -i input.mp4 -filter_complex " \
    [0:v]select='between(t,45,50)'[v1], \
    [0:v]select='between(t,23,30)'[v2], \
    [v2]setpts='(PTS-STARTPTS)+(5/TB)'[v2], \
    [v1][v2]concat[outv], \
    [outv]scale=720:-1[outv]" \
    -map [outv] output.avi

Remember that if you want to use this for any other file, you will need to adjust the (5/TB) part to match the end of your first clip.
While I'm a very experienced programmer, I'm relatively new to FFmpeg in-depth; so it's possible that someone else here will have more details for you to consider.

Thank you very much. I tried this and I'm reporting my results:
The output video starts with the first frame of the second video and gets stuck there until it reaches the original time of the second vídeo 45 sec, than it starts playing the second video and after that the first, so after 45 everything starts playing as intended but how I get rid of that 45 useless seconds in the beginning of the video where it shows the first frame of the second vídeo? Thanks.

Something else, when I save the output video as gif than there are no 45 seconds with stuck frame in the beginning. But when I save it as avi or mp4 there is...

There was also a gap of a couple of seconds from the second to the first video to start playing but then I remembered something from another topic here in this site and I changed setpts='(PTS-STARTPTS)+(5/TB)'  to setpts='N/FRAME_RATE/TB and that fixed the gap...

Yeah, we've gone a pretty long way from taping film together in a darkroom; it's all about those PTS timestamps now. Think of it as how far along the strip the frame is; whereas N is the frame number, and TB is closer to the speed of the film. If you bump into an issue with gaps between frames, and your video twiddling its thumbs, the problem is almost certainly in the PTS. You need to set it to the exact time for that frame. Admittedly, as capable as FFmpeg is, it's pretty advanced stuff and the parameter names tend to throw people.

@RicardoBohner Politely, if this does solve it for you, could you accept it as an answer? Others in the future are going to have the same problem, which is most of what Stack Exchange exists to address. Accepting the answer will make it easier to find this with a simple search, and will hopefully save them some time.

What is the -map switch for?

-map tells which output stream to add to the final render. With filter_complex you can literally have dozens, and FFmpeg won't assume anything. So, -map tells it to map that resultant stream to the actual file instead of throwing it out.

Ah ok, thanks a lot

After playing around with @Michael Macha's answer I figured out a way to do what I wanted without having stuck frames and extra seconds on the beginning of the video:
ffmpeg -i "Input.mp4" -filter_complex \
"[0:v]select='between(t,45,50)'[v1], \
[0:v]select='between(t,23,30)'[v2], \
[v1][v2]concat[outv],[outv]scale=720:-1[outv], \
[outv]setpts=N/FRAME_RATE/TB[outv]" -map [outv] output.avi


text:
How to create a video that can be uploaded to Twitter in Mac?
I'm using Mac to make videos.
I have iMovie and Final Cut Pro.
It seems that the videos that can be uploaded to Twitter have a specific formats.
Does anyone know what's the easiest way to make such a video in Mac?

From Twitter's support page:

We currently support MP4 and MOV video formats on mobile apps.
On the web, we support the MP4 video format with H264 format with AAC
audio. You can upload videos up to 512MB, however you will be prompted
to edit videos to 2 minutes and 20 seconds or less in length.

You can export an h264 format video directly from Final Cut.


text:
What cable for 200' run between camera (video/audio) and ATEM switcher
I am running a video/audio signal from a camera in a lobby to a Blackmagicdesign ATEM switcher that are about 150' apart but cable run will be closer to 200'. The video/audio from the camera in the lobby will be streamed online.
My initial design for your feedback...
Lobby will have camera with a Hollyland Mars 400S SDI/HDMI Wireless Video Transmission System. Once the signal is at the HDMI rx in the lobby it will output on an SDI port and make a 200' cable run to the Blackmagicdesign 8 port ATEM switcher.
Lobby Camera <--HDMI cable--> HDMI tx <--wireless--> HDMI rx with SDI output <--cable?--> Blackmagicdesign ATEM switcher to the live stream.
Will RG59 75ohm cable work for that 200' run or does it need to be a special "SDI" rated cable? Again, it needs to transmit both the video and audio.
Thanks.

You need to use cable specifically designed for SDI. RG59 essentially only defines the impedance and capacitance of the cable, not the return loss and attenuation characteristics. You can use reference charts from cable manufacturers like Belden and Gepco to select the right cable for your situation.

Thank you for the response and pointing me to the manufacturer charts. That is what I needed.

Make sure you choose a cable with the right jacket, in case code in your area requires plenum or riser rated cable in the spaces you will be running it through.

Great point. I'll make sure that is part of the cable selection process. Thank you.


text:
phone vs dslr vs webcam for making videos
I'm using OBS to record some videos for youtube with a webcam. Right now I'm using the Logitech BRIO Ultra HD. It's alright... but definitely could be better. I'm looking to upgrade to something high quality but before I shell out for a $2000 Sony A7 III which I don't feel like I can really afford, is an iPhone camera also a possibility for this usecase?
I have an iPhone 7 atm, is it already better than the Brio? If I get the iPhone 12/Galaxy S21 would it be what I need?
I'm just looking to vastly improve the quality of my videos. Thanks.

Maybe describe what you don't like about the current quality, or even provide a link to an example. Better lighting / filming environment will almost always improve visual quality more than changing camera (for what you are describing), unless your current camera is indeed exceptionally poor for some reason (I'm not familiar with it).

You’re forgetting mirrorless; cheaper than dslr because the optics are simpler, but just as good image quality. Sony just announced they’re no longer making dslrs.

videos for youtube

This does not describe your projects. Youtube is a place to publish your videos, does not tell the content of them.

but definitely could be better

What could be better? This is the point. You need to know what do you want to imporve.
Are your videos about gaming, where you are on a little corner on a green screen?
Are your videos about you talking to the camera on your room? Do you need to use the bathroom because it is the only place you have? Or you do outdoor videos. Do you really need to actually improve the image quality?

Let me narrow this a bit. Let me asume you are on a bedroom infront of a fixed setup, your computer and your camera. Here is a list of what would I check before getting a new camera.

Light.

Not only the ammount of it, but how does it look. Find a video where you like the light. Is it rim light or a big diffuse light? Is it lateral or on top of the subject?

Background.

Leave a good space behind you. You do not want a mug shot. Put context on it, remove yourself from the shoot and see it as the main subject, and see if you like it.

Sound.

Good sound is probably more important than excelent video quality.

If you still need better video, and you already tested your current phone. (Yes one first section on this answer is, test your phone, and find out if it is better for you) what you want to have on a new camera is

Looks

Flexibility. Duration of the shoot without heating, focus options (manual or good auto focus) conection, etc.

And I leave the looks to the last. A mirrorless or dslr camera have its limitations but have specific lenses that will actually make the image look good. The main things to consider are focal length and aperture.

A focal length of 35mm or more on a cropped sensor.
A wide aperture, a typical recommendation is 1.8 but needs a fixed distance or a superb auto focus system.

All this answer is not to tell you what you need, it is what you need to investigate to find out what you really need.


text:
Change color to look as how a color blind person sees
I use DaVince Resolve and I want to color modify a video in order to show how a person with protanopia sees (protanopia is a form of color blindness). For that purpose I need to change these colors:

to these:

I believe that this is possible in the RGB Mixer menu of the DaVinci Resolve:

yet, I haven't yet found the right combination of the RGB values. Also I don't care about the exact values of the green-olive and the purple as long as the look like green-olive or purple..
Any suggestions on how to modify the colors, would be appreciated.

With these values, I get the results shown below.  Note that your color management settings in Resolve will affect your result, and so will the input color space of your source.  To avoid misinterpreting the color space of an unknown source, I'd recommend using the EBU color bar generator, wrapped in a Compound Clip as a test source.  Wrapping the Generator in a Compound Clip allows you to apply the RGB Mixer, whereas Resolve normally protects test patterns from manipulation.
The values I used were:

R Output:
R=0.5, G=0.5, B=0.0
G Output:
R=0.5, G=0.5, B=0.0
B Output: R=0.0, G=0.0, B=1.0

I also found that unchecking the "preserve luminance" checkbox gave me better results, when I tested against other protanopia images I found on the web.
For this example, I used DaVinci YRGB Color Managed as my color science, with the default rec.709 settings, and set the input color space of your example .jpg to sRGB.  However, when you apply this effect to a video, you should use whatever input space the video happens to be.  Using Resolve YRGB color managed with a known input space will ensure that the transformation is applied linearly (correctly), before being transformed into your desired output space.


text:
How to realistically add planet in the sky using 3d camera tracker and avoid overlapping with objects in the foreground?
Quick summary of what I want to create with AE:
I have a drone shot and I want to add a realistic planet in the sky/horizon by using 3d Camera Tracker in After Effects.
What I want:
While flying past a wind turbine I want to create depth by showing the turbine in front of the planet in the horizon to create some kind of realistic depth.
The Problem:
Currently the planet in the horizon is in the foreground and covers the wind turbine and its moving rotos etc.
What I tried so far:
I know I have to use the masking tool but I am not sure about the order of the procedures of how to get to my results. I've created a mask and tried subtracting but this didn't go as expected. I also readjusted the mask shape and keyframed the mask path for the relevant frames where the turbine should be in the foreground. But this didn't go out as expeted.
Can someone please guide me through the the procedure to get to my final result?
I attached an image which shows the end result I want to achieve in my video:

Thank you

If the blades are rotating, and the camera is moving, you need to create a good foreground layer with anything the planet is supposed to be obscured by.
So from the image it looks like it will be obscured by the spinning rotors.
You need to find a good way to make a layer containing only the rotors.
You could make a mask and move it frame by frame, but if you have more than a few frames this method will take a long time.
You could try using a key - isolating your foreground based on hue (colour), brightness or saturation (how much colour is present).  The blades look like the whitest thing in the image, so this might work, but probably won't give you the result you're looking for...
Or you could rotoscope the blades.  This will take a while, but will probably give the best result. The new rotoscope v2 in the latest versions of After Effects is really amazing, and combined with some careful feathering / motion blur settings will probably work perfectly.  It will still take a while though.
To get the planet in the right position in the sky, you need to make a camera track of the scene, then place the planet as a 3D layer at the right distance and scale.

Thank you for your reply. I'm going to give it a try with the new rotoscope tool. But just in case I'll have to do it manually frame by frame, what are the concrete order of procedures? First let 3d Camera Tracker analyse the footage and create a camera. Then position the planet where I want it to be and see what objects obscuring it. Then I have to create a mask in my sequence and move it frame by frame. What options do I use (Add, subtract or invert mask). When I tried that I only got a black spot.

You need to add a copy of your video (so you have two layers, only the bottom one needs the planet on it). Rotoscope the top layer - when you create your mask the only thing you will see is the bit of video inside the mask, the blade in this case and it will sit above the planet because it is the top layer. If you use more than one mask you will need to set it/them to "Add".
You'll have to add 3d Camera Tracker only to the bottom video where the planet is. Also be aware that you only need to mask the areas that go over the planet when they go over the planet.


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FFmpeg: Getting this error while trying to add a logo to video (Unable to find a suitable output format for ..)
Hey guys I want to add a logo to my video with ffmpeg but I am getting this error while running the below command. What is the reason? Please do help.
`Unable to find a suitable output format for 'overlay=x=main_w-overlay_w-(main_w*0.01):y=main_h-overlay_h-(main_h*0.01)' overlay=x=main_w-overlay_w-(main_w*0.01):y=main_h-overlay_h-(main_h*0.01): Invalid argument.`

I am using python subprocess to run ffmpeg commands.
subprocess.call([settings.VIDEO_ENCODING_FFMPEG_PATH, '-i', input_file_path,
                '-i', logo_path, '-filter_complex','scale=1920:1080',
                'overlay=x=main_w-overlay_w-(main_w*0.01):y=main_h-overlay_h-(main_h*0.01)',
                '-codec:v', 'libx264','-crf', '18',
                '-preset', 'slow', '-b:v', '1000k', '-maxrate', '2000k', '-bufsize', '2000k',
                "-pix_fmt", "yuv420p",
                '-codec:a', 'aac', '-b:a', '128k', '-strict', '-2', output_file_path])

Thanks

The entire filtergraph should be one argument.
'-filter_complex','scale=1920:1080[main];[main][1]overlay=x=main_w-overlay_w-(main_w*0.01):y=main_h-overlay_h-(main_h*0.01)',

Hey, thanks a lot for the response, it works well now. Is [main] a keyword like variable or just a naming one? Could you also tell me how can I decrease the size of the logo image?
Thanks.

It's a linklabel. See last para at https://superuser.com/a/1172501/


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Making a collage of several videos
I am trying to make a video showing me playing various instruments arranged together in a song. The effect that I want to achieve is exactly like this.
The person in the video is a friend of mine, and he told me he created the video using iMovie. But he was only able to mix two videos at once, so he resorted to mixing two videos, exporting, mixing together with another one and so on.
I already have the various snippets filmed, and I would like to put them together in a collage, but using a software that allows superimposing many videos at once ( at certain points I have eight). What kind of software allows this?
Ideally I would use a Mac, but Linux is also fine (as long as it does not need enormous amounts of resources, since it is an older machine)

Blackmagic Design’s DaVinci Resolve offers a free version, is available on Mac, Linux, and Windows, and is well-suited to creating video collages. One of the effects added in version 17 is actually called “video collage” and greatly simplifies the process over past versions.  Additionally, if you synchronize the timecode of all cameras before you start shooting a multi-camera event, it offers features like “live overwrite” and “sync bins” which simplify typical multicam edits.
Adobe Premiere is a viable alternative, but does not run on Linux, and is not free.
Final Cut Pro X is a Mac-only alternative, and also does not offer a free version.
Avid Media Composer is the other big-name player in the NLE space.

Thank you, DaVinci resolve seems exactly the tool I was looking for!


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Animating a sequence of still frames
I am taking a picture a day of someone, with the aim of obtaining an animation in a few months. The person is more or less always in the same pose, but of course there are minor variations day by day.
What I would like to do is to mark some reference points in each picture in order to help some software animate smoothly.
I am thinking of using a morph editor, but I wonder whether the morphing will create an uncanny valley effect. Maybe that would be less apparent if each picture only lasts a fraction of a second. In any case, I would need an editor that allows morphing hundreds of pictures, instead of just two.
Or maybe I should look into some video editor, put the frames and do some manual adjustments? I am a programmer, so the option of writing some custom code is also fine. Every suggestion on how to create this short animation is welcome.
Ideally, I would like to use some software available on Mac, but also using Linux (desktop) or Android is fine.

The key thing is controlled lighting, and a camera positioned so that it never moves (locked off on a tripod).  It really helps to use a plain background - a solid colour is good.
Beyond that, you could assemble the images in After Effects, or as an Image Sequence in QuickTime Player, Screenflow, or many other packages.
After Effects is useful for things like this as you could overlap the images and make them semi-opaque, to see whether you need to tweak their positions very slightly.
If the lighting matches on each shot and the camera is in the same position, and the model stands at the same point each time, you may not need to morph the shots, but if you do, the built-in Liquify plugin can help with this.