text:
Marker animation trigger from parent composition
Is it possible to trigger animation from parent comp layer? I have been trying this expression with my basic coding skills but couldn't make it work.
n = comp("myparentComp").layer("myLayer").marker.key(time);
if(time < marker.key(n).time){ n=n-1;
}
if(n==0){ n=1
}
t=time-marker.key(n).time;
thisProperty.valueAtTime(t)

Sounds definitely doable but I need some more data. What are you trying to "trigger"?

Totally possible, but there are some problems with your expression.
n = comp("myparentComp").layer("myLayer").marker.key(time);

In this line n is going to return a marker key object. However the last part of the line uses the current time in the method marker.key(time). This won't work. The marker.key() function expects an int referring to the number of the marker (1-indexed, so the first marker is marker.key(1), because WTF adobe). A marker key has a time property, which is probably where you're getting confused. Also then you're treating n as if it's an integer, and you use a variable marker without declaring it or giving it a value.
If you want the animation to trigger on the first marker, it should look like this:
var marker1time = comp("myparentComp").layer("myLayer").marker.key(1).time;
if(time < marker1time){
  t = 0; //hold the animation until the first marker
} else {
    t=time-marker1time; //will start at 0 at the point where time == marker1time
}
thisProperty.valueAtTime(t);

Some basic JS tutorials would probably help. I recommend the w3Schools ones, they're web-design focused, but almost all JS tutes are.

Nice thanks, it worked. I got another question, would that be possible to have this expression for the animation to react to every markers of comp("myparentComp").layer("myLayer") ?
This one works for the markers on the layer but I can't make it work with the one you wrote.
n = marker.nearestKey(time).index;  if(time < marker.key(n).time){ n=n-1; } if(n==0){ n=1 } t=time-marker.key(n).time; thisProperty.valueAtTime(t)

I don't quite understand what you're trying to do. What do you mean "have the animation react"?


text:
How would I produce unevenly colored subtitles with aegisub
I would like to put text on screen that would have non-even colour. I.e. if the text were "subtitle", "s" would be in say white and "e" in gray. Is there a way to accomplish this using Aegisub/ASS subtitle format? So far, it let me do anything I needed with graphical subtitles, but I cannot figure how to do this one.
(On a related note - what is the best way to ask ASS-related questions since the aegisub forum is down?)

One can use the Hydra Aegisub plugin from here: https://unanimated.github.io/ts/scripts-manuals.htm#hydra
And it all works.

source: Stack Exchange

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

sort: votes


text:
ffmpeg quadruple video and audio play speed
I have a video file and I want to quadruple the video and audio play speed. I followed the instructions here
https://trac.ffmpeg.org/wiki/How%20to%20speed%20up%20/%20slow%20down%20a%20video
So I tried these commands:
ffmpeg -i 02.mp4 -strict -2 -filter_complex "[0:v]setpts=0.25*PTS[v];[0:a]atempo=2.0[a];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" -map "[a]" 02ff.mp4

This command quadrupled the video play speed but only doubled the audio play speed.
So then I tried this:
ffmpeg -i 02.mp4 -strict -2 -filter_complex "[0:v]setpts=0.25*PTS[v];[0:a]atempo=2.0[a];[0:a]atempo=2.0,atempo=2.0[a]" -map "[v]" -map "[a]" -map "[a]" 02ff.mp4

But still the same issue.  I've tried a few other variations of this command but I just get errors.
What's the correct command to quadruple video play spdd and audio play speed?

The audio filters should be chained one after the another. Your syntax generates two audio tracks, each doubled in speed. Also, since you're dealing with one input and one output, you can just use simple filters.
ffmpeg -i 02.mp4 -vf "setpts=0.25*PTS" -af "atempo=2.0,atempo=2.0" 02ff.mp4

Thanks, I added the -strict -2 filter just after the 02.mp4 to get rid of the error  The encoder 'aac' is experimental but experimental codecs.  Then everything worked

That message is for pre-2016 builds of ffmpeg, so you should upgrade.

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


text:
I have a .mkv video file I need to use but it is apparently infinite
So I'm trying to make a YouTube video and I have recorded some gameplay and some facecam footage. When I went over to edit in Kdenlive (my video editor of choice) I tried to import my facecam footage (.mkv formatted) which was shot using the default camera app on my Chromebook. It crashed Kdenlive but before it crashed I looked at the time it predicted to be the end of the video which seemed to be extraordinarily long! Just dragging the clip to my timeline caused my computer to freeze up and then the program to eventually crash. I opened the clip in VLC and the playhead doesn't even move. In fact, VLC says that the video is 0 minutes and 0 seconds long even though I know for a fact that it is 42 minutes long. Attempting to move the playhead makes strange artifacts appear on my video clip and then the playhead jumps to 0:00 and it plays fine. This is extremely frustrating because I don't know how I can convert this so that it has a correct start and end time. I cannot edit the video of course because my video editor tries to import an infinite (or at least really massive) video. Strangely enough it plays fine in the Google Drive video player and I believe the native Chrome OS video player.

So I've found the issue to be related to inconsistent framerates. I found that running the video through ffmpeg with ffmpeg -i yourfile.mkv -c:v copy -c:a copy -r 30 newfile.mkv actually fixed the issue entirely. Now I can open the file correctly and it appears to be 42 minutes as expected. More information here.

Exactly what I would suggest. Time code issues are almost always fixed by rewrapping the container. That's exactly what this ffmpeg command does.


text:
How do I darken a video smoothly halfway through?
I have a 10 second video clip. At about the 5 second mark, I'm showing a text overlay. I want the video to keep on playing, but I'd like it to be darker when the text is showing.
I don't want an abrupt transition of:

0:00: normal video (100% bright), no text
0:05: darkened video (50% bright) w/ text overlay

I want a more smooth transition such as:

0:00: normal video (100% bright), no text
0:04: begin darkening the video
0:05: darkened video (50% bright) w/ text overlay

How do I do this in iMovie?

As Naved mentioned, you need to split the clip. The most important part, however, is using a Cross Dissolve, which smoothly transitions from one clip to another.

Split the two clips in half so you go from [clipA] to [clipA1][clipA2].
Modify clipA2 to have whatever effects you want such as darkening the video.
Add a Cross Dissolve between the two clips
(The cross dissolve is so common it has a keyboard shortcut,
⌘T, to add it to both sides.)

In fact these three steps are so common, you can find a one-click solution for doing the same with these effects via the Modify > Fade to menu:

Black and White
Sepia
Dream

A third and final shortcut/tip is even if you want to darken the video, you could use the "Fade to Black and White" feature, then remove the Black and White effect and apply whatever other transformations you want to the video.

First of all the transition that you are willing to do is according to my knowledge an abrupt transition and according to me dimming 50% of brightness in just 1 second will look less smooth and more immediate than the dimming/reduction of brightness in 5 seconds.
Preferably, I would like you to use Adobe Premiere Pro and/or Adobe After Effects, if you like such transitions, in which "keyframes" do a nice job.
But, in iMovie, you don't have a good keyframe feature. So, what you can do here is answered by AppleMan1958 (quoting it in his own words below):-

Mar 9, 2012, 5:07 AM AppleMan1958 in response to Penfold941
iMovie does not contain keyframes like FCP, but you can simulate it quite a bit. Just drag your mouse from your first "keyframe" to the end "keyframe" within a clip so that you have selected a range of clips. Then right-click within the range and select "Split Clip". Now you can apply a Ken Burns zoom to this section. This works for many effects.
What you cannot do is keyframe the location of a motion graphic to simulate movement, for example.

You may read the full thread here
So, you might have got your answer, if there remains any other confusion, you may ask in the comment section below. But, try this solution out before asking or assuming any confusion. Hopefully, you might get rid of your problem yourself.


text:
Can't set ffmpeg request header when using file for input
I'm attempting to set headers (as suggested here) for my ffmpeg concat command like so:
ffmpeg \
    -f concat \
    -safe 0 \
    -protocol_whitelist file,http,https,tcp,tls \
    -headers $'Content-Type: audio/wav\r\n' \
    -i 'inputs.txt' \
    -c 'copy' 'output.wav' \
    -v trace

where my input file is structured as such:
file 'https://path/to/file1'
file 'https://path/to/file2'
file 'https://path/to/file3'

However, when I run the command, ffmpeg doesn't set the headers, as seen by the output of -v:
[http @ 0x7fa133d01080] request: GET / HTTP/1.1
User-Agent: Lavf/58.20.100
Accept: */*
Range: bytes=0-
Connection: close
Host: localhost:3001
Icy-MetaData: 1

What's strange is if I set my input not through an input txt and just through  -i /path/to file (as seen below) it works just fine.
ffmpeg \
    -f concat \
    -safe 0 \
    -protocol_whitelist file,http,https,tcp,tls \
    -headers $'Content-Type: audio/wav\r\n' \
    -i 'https://google.com' \
    -c 'copy' 'output.wav' \
    -v trace

Output of -v:
[https @ 0x7fed3ac03940] request: GET / HTTP/1.1
User-Agent: Lavf/58.20.100
Accept: */*
Range: bytes=0-
Connection: close
Host: google.com
Icy-MetaData: 1
Content-Type: audio/wav

Not sure why reading the inputs through a file would affect the headers getting sent. For now the workaround is to use a string concatenating all of the inputs (a bit messier than I'd like), but I'm curious if anyone might know why this is happening.
UPDATE: According to this post I have to read inputs through a text file, so I'm back to square one....

When a single input is directed fed to ffmpeg (-i), various options can be set on it, depending on what the input reader allows and recognizes.
However, FFmpeg does not natively read an input list from a text file. There's a bespoke module called the concat demuxer, invoked by -f concat, which parses the input list, opens each file and concatenates them. To the main ffmpeg pipeline, this is presented as a single input, generated by the concat module. And the concat module does not recognize or carry over options meant for the individual files listed within the text file. All listed files can only be opened with default parameters of their respective demuxers/decoders/protocols..etc. This is a limitation. You may open a feature request at trac.ffmpeg.org to change this.
What you could do is read all inputs directly.
ffmpeg \
    -headers $'Content-Type: audio/wav\r\n' \
    -i 'https://google1.com' \
    -headers $'Content-Type: audio/wav\r\n' \
    -i 'https://google2.com' \
    -headers $'Content-Type: audio/wav\r\n' \
    -i 'https://google3.com' \
    -headers $'Content-Type: audio/wav\r\n' \
    -i 'https://google4.com' \
    -filter_complex "[0][1][2][3]concat=n=4:v=0:a=1" \
    'output.wav'

For WAV inputs, re-encoding to WAV won't lose quality.


text:
Text Animations - Range Selector Not Moving - After Effects
I am trying to animate the position of my text to create a text animation (as seen here) and I have followed these exact steps:

Created a text layer Clicked "animate" and chose "position"
Renamed my Range Selector to "initial position"
Added a keyframe with the End set to 100
Moved forward a few frames
Added another keyframe with the End set to 0

When I play the animation, nothing is happening. The text remains on screen without any movement.
What am I missing? I followed the YouTube tutorial step-by-step so I'm lost as to why it doesn't work for me.

Have you adjusted the Transform Position, to make the letters move downwards? The Range Selector only tells AE which letters you want to affect. The transform position tells it how far and which way you want the lettters to move.


text:
What is the name of the effect where every other frame is dropped and the remaining frames are duplicated?
What is the name of the effect where every other frame is dropped and the remaining frames are duplicated?
Like this...
ABCDEFG   // 1: original
ACEG      // 2: every other frame deleted
AACCEEGG  // 3: remaining frames duplicated

Does Final Cut have this feature?
If not, how do I do this?

Thank you. I found some nice tutorials on the subject when searching for "strobe effect"/"strobe filter". Please create an answer with this in it (rather than a comment) so that I can accept it as the correct answer. Thanks again.

In After Effects it's called posterize time

Back in the days of analog video, TBCs used to call that a strobe effect. It looks like Premiere has a strobe filter, but I don't know if it can be configured to do the freezing, instead of flashes.


text:
How do I open only one library in iMovie?
I'm creating different libraries for each of my projects. When I attempt to open a new library via File > Open Library, it has both the old library open and the new one open.
I want to close the old one so I don't accidentally create projects within the old library.
File > Close Library is disabled. If I try to close iMovie and re-open it, it remembers the last library that was opened.
How do I open just a new iMovie Library?

I was able to right-click on the library name and choose 'Close library ...'. I had to make sure the library I was trying to close wasn't the active library. When I had the editing windows up for the library I was trying to close, the 'Close library' option was greyed out. -- Thanks for your insightful solutions! Three of your posts have helped me now :)

Find the Library in finder (e.g. ~/Movies), and double click it.
You can be sure that it's the only open Library by using the drop down menu in Projects:


text:
FFMPEG demux .264 for burning in scenarist
I have a very specific pipeline I need to set up, it starts with an mov file from Avid which gets transcoded to mkv for internal review and .264 for burning to Blu-ray in Scenarist. It goes:
.mov (DNxHD) -> .mkv (h264) -> .264
For purposes of quality and speed I transcode to .mkv in FFMPEG and then when the time comes to make a Blu-ray I demux the mkv to the .264, however I'm told this is throwing a very ambiguous error in scenarist and I can't figure out what I'm doing wrong. Interestingly if I transcode directly to .264 instead of demuxing it there is no problem, so this appears to be a metadata issue. Here's the demux recipe I'm using:
-i input.mkv -codec copy -bsf:v h264_mp4toannexb output.264
Here's the transcode recipe if that is useful:
-i input -c:v libx264 -preset fast -tune film -b:v 20000k -maxrate 35000k -bufsize 30000k -level 4.1 -pix_fmt yuv420p -x264opts bluray-compat=1:open-gop=1:slices=4:keyint=24 -r fps outfile.mkv

Add -bsf:v dump_extra=k and check. Annex B bsf is auto-inserted since v3.2

@Gyan Just tried that and Scenarist says "Media file invalid". If I inspect the file it seems almost all metadata is now gone, and if I check it in FFPROBE I get a massive stream of PPS and SPS errors. Tried dump_extra=all and got a 0kb file...

What was the original Scenarist error? Workaround is to transcode to .264 and mux that into MKV.

@Gyan The error says "Parse error: The garbage data exists in ES. offset=0, size=773". I am also re-evaluating if we really need to go to .264. If some other format works then I believe I can change this requirement, though I did just try an m4v and it did not work. (though encoding an m4v from Adobe Media Encoder did work...)

Contacted Scenarist and they gave us a 46 page white paper on Blu-Ray specifications! Wasn't quite able to glean anything useful out of it yet, except that "Video streams shall be...MPEG-4 AVC video format (ISO/IEC 14496-10) compliant...". Don't know if anyone can decypher what that means or not...

The error msg is helpful. Can you generate and share a 5 second sample of both methods - direct to .264 and via mkv, using your original commands?

@Gyan for various reason sadly no, I cannot upload a file. However if you just take the above recipe that is exactly what I'm using - I only change the output file name from .mkv to .264 respectively. I'm on version 4.0.2 win64.

@Gyan One other interesting thing to note is that if I compare a file encoded .mov->.264 vs .mov->.mkv->.264 with FFPROBE the latter gives me some PPS and SPS errors. Otherwise everything else is exactly the same, so that appears to have something to do with the problem.

@Gyan I'm willing to pay some bounty to figure this one out! I'm at a dead end, not sure what else to do. If you can figure this out I'll put up a bounty tomorrow and sacrifice a few reputation.

I'll look at this today or tomorrow, time permitting.

@Gyan Thanks! Just tried encoding to 264 then muxing to mkv as you suggested and got the following error: Cant write packet with unknown timestamp. Adding -fflags -genpts as some other users suggested did not fix it...

The demuxed H264 stream has the same metadata content, however it is rearranged, compared to the directly produced .264 stream. So far, I don't see a way to rearrange it to match.
So, transcode directly to 264 and use mp4box to generate a stream inside a container
mp4box -add direct.264 -new muxed.mp4

You can then use ffmpeg to mux to MKV.
ffmpeg -i muxed.mp4 -c copy muxed.mkv

mp4box is part of the GPAC project. Get a nightly build from https://gpac.wp.imt.fr/downloads/gpac-nightly-builds/

To do this entirely within ffmpeg, you can use the tee muxer to pipe a AVI mux to another ffmpeg instance
ffmpeg -i input.mov -map 0:v -vsync cfr -r fps -pix_fmt yuv420p -c:v libx264 -preset fast -tune film -b:v 20000k -maxrate 35000k -bufsize 30000k -level 4.1 -x264opts bluray-compat=1:open-gop=1:slices=4:keyint=24 -f tee "scenarist.264|[f=avi]pipe:1" | ffmpeg -f avi -i - -c copy -y playback.mkv
Verify the

Thanks Gyan, but unfortunately this is the backend for an application I built and I need it to be portable so GPAC does not work. However I did just figure out a ridiculous but workable solution. I cannot mux .264 directly to .mkv, however this is the only workflow I've found that does the trick: mov -> 264 -> avi -> mkv. For whatever reason the avi muxer seems to regenerate whatever metadata is needed for the mkv... Because they're all just stream copies it isn't too slow. Do you know of a way to go 264 -> avi -> mkv in one process?

Added workaround. There are bugs with the method you've used. In H264 streams with hierarichical B-frames, ffmpeg may reorder B-frames presentation order. However, Blu-ray limits the B-frame count, so you may be OK. Test a few MKVs, though.

What's the barrier with GPAC? It's FOSS and cross-platform. Installation is not needed.

Thanks for all of your help! I couldn't find a portable version of GPAC, just an exe? Your tee mux recipe gave me a better idea, why not just transcode a .264 and .mkv at the same time? Then I don't need to mux the .264 later, that can just go straight to scenarist and I can mux the mkv with chapters and audio later. Don't know why I didn't think of it before!

why not just transcode a .264 and .mkv at the same time? --> that's double CPU + RAM.

Even with the tee muxer?

The bitstream format demanded by a container like MP4/MKV requires a global_header, which has to be implemented by the encoder. .264 requires in-band headers, which is the direct opposite. The tee muxer is meant for when identical streams have multiple recipients.

I see, I'm not very familiar with headers. It did seem to work though without a problem, does that make sense? I didn't benchmark it or test it very thoroughly beyond running out a 10 second test video (which seemed to work okay, and scenarist at least imported)


text:
FFmpeg encode variable input framerate
I have a Qt application running, i hijack the openGL frameBuffer when a new frame has been rendered. A new frame is drawned when only some changes appear in the scene, so no constant frameRate.
Now i want to send those raw rgba pixels value to ffmpeg, I use this wonderfull link http://blog.mmacklin.com/2013/06/11/real-time-video-capture-with-ffmpeg/ to encode my input stream, but in the end i have a video where each frame has been concatenate with a constant time between each.
To clarify, if i am not updating my application for 1 sec, this halt won't appear in the final video.
I use this command line to encode:
ffmpeg.exe -f rawvideo -vsync 1 -pix_fmt rgba -s 1172x768 -i - -threads 0 -y -pix_fmt yuv420p -b:v 8000K -vf vflip output.mp4

and i write in to my stream with:
uchar* buffer = (uchar*)malloc(count);
fwrite(buffer, sizeof(char), count, m_ffmpeg);
fflush(m_ffmpeg);

I saw the vsync option, i use it with different values as output and input options, but it seems to have no effect.
I might be able to store the delta time in a .txt file if it can help.

Add -use_wallclock_as_timestamps 1 before -i

work as a charm, thank you ! Is there some parameter of  -vsync to complete the gap we should take in to account ?

some parameter of -vsync to complete the gap? You mean, make a CFR video.

By default i think frame are dupplicated to fill the gap between 2 of my acquisitions. I don't know what would be the effect of setting -vsync 0 and if it's relevant or not.

Hi @Gyan - I know this one is a really simple one, but if you post as an answer we can properly upvote your post and the OP can accept. That would really help. Thanks.

When receiving frames from a raw input i.e. one without embedded timestamps, ffmpeg will assign timestamps in serial order, thus losing the temporal relation between the incoming frames.
When the difference in times is important, you can add -use_wallclock_as_timestamps 1 before the input -i. This will assign the system time at time of receipt as the timestamp. Not perfect, as there may be jitter during the transport of the input, but better than the default behaviour.
vsync is somewhat of a misnomer. It takes effect after filtering and is generally used to select between generating a constant (cfr) or variable frame rate (vfr) stream.

On some systems, I think i have some delay between the moment I send my data and ffmpeg receive it. Is there a way to use a txt file where I note the acquisition time from each of my frame and then reorder a video based on thoose new timeStamps ?


text:
Flickering when doubling shutter speed
I have a Nikon D750 and cannot figure out the logic behind video (or still photos in live view) and flickering. I live in Norway, so the electricity is 50 Hz. If I shoot video at 1/50 or 1/100 second I get no flickering when using indoors (1080p 24 fps). However, if my shutter speed is increased to 1/200, 1/400 and so on I get flickering again. Does anyone know why this is happening? I also tried to record video at 1/200 and play back (to ensure that it is "real" flickering and not just an issue with the live view preview) and the issue persists. I though any multiplier of 50 should provide a flicker free video, but this appears to just be the case for 1/50 and 1/100 second. Does it have anything to do with the readout time of the sensor/rolling shutter somehow?

Sadly this isn't how it works.
It could work with 25FPS and 1/200 if the shutter is precisly on the light impulse.
Also keep in mind that even if the electricity is 50Hz, the light could have a refresh of 100Hz.
Or you were just lucky that the shutter allways was on the light impulse.
Solution:
Well, sadly you don't really have a direcr solution for this one. But youbhave two Options:
1. Buy yourself some Video Lights (Sometimes also normal lights have a label "Flicker free" those should work too)
2. Do not shoot with such high shutter speeds.
If you know 180° rule and just do it for artistic reasons, skip this part:
You should allways record with dpuble the shutter of your FPS: 25FPS=>1/50 50FPS=>1/100
This will give you the most natural look.
If you choose a higher Shutterspeed, the footage will kinda look robot-erisch and unnatural.
If you choose a lower shutterspeed, it will have more motion blur and feel almost dreamy.
But you may want to use this for artistic reasons, a slow shutter for a dream sequence or a faster shutter for sport video where you wsnt to see everything and stop the video.

Thanks for the clarification. Btw, the reason I need the higher shutter speed is because I want a shallow depth of field and at base ISO the 180° rule overexposed my video. I also don’t have an appropriate ND filter and since the videos have limited motion increasing the shutter speed is a cheap solution.

If you don't have much motion it can work. But normally lowering/highering the shutter is just a bad solution. Yous hould allways try to use NDs or more light. BUT: learn the rules like a professional and break them like an artist

Lag. The time between shutter close and shutter open, when the cam is processing and saving the image, is real and adds up. Just guessing, but I'm pretty sure I'm right. If you can set exact shutter speeds, try just a bit higher than 1/200, like 1/205, and see what happens.


text:
How to avoid audio border magnetics on Final Cut Pro X?
This might be an easy question, but I'm not able to find the answer.
Sometimes the audio clip is slightly small than the video clip. I need to move the audio just a little bit (like less than 1 second), however final cut moves it to the opposite border straight away.

Is Snapping (N) off?

It looks like Snapping is turn on. Toggle it with N or use the snapping icon (next to clip view options and transitions etc).

Zoom in for more precise placements and turn snapping off.


text:
How to retroactively extract media out of a Final Cut Pro library?
I see that in Final Cut Pro, I can go to File > Library Properties > Storage Locations > Modify Settings and see the following screen:

Set storage locations for the library...
Newly imported or generated media, custom Motion content, cache files, and library backups will be stored in the locations you choose. Existing media, Motion content, and backup files remain in their original locations.

This seems like a great way to create a lightweight backup (e.g. similar to how I had to manually do it in iMovie).
However, I accidentally started editing my project before having this setting enabled. My Final Cut Pro contains duplicates of all the media I imported, and is now Gigabytes larger than I'd like it to be. (Since I already have the original media saved in another location.)
How do I retroactively extract my media from my Final Cut Pro library, in such a way that preserves all the editing I've done?

Update: In Preferences, there also seems to be a setting that affects how media is imported:

Import
Files: Leave files in place (instead of Copy to library storage location)

However, this also appears to only work for new media that is imported rather than retroactively applying to existing media.

I think the best way would be to create a new library with a new project, then select the entire timeline in the old project, then drag all into the new project in the new library. That should give only the media used. Make sure that in the settings the leave file is selected.


text:
Automatically scale video on import to sequence resolution
I have a multicam setup mixed with 1080p cameras and 2160p cameras (So I can zoom in on them)
But when I import the 4k clips into my 1080p sequence, they are "zoomed in 200%".
Is there a way to automatically set UHD clips to 50% size on import?

You can achieve this by the using Default Media Scaling preference, which takes effect when you subsequently import media and/or add to the timeline.
Edit > Preferences > Media > Default Media Scaling and choose "None", "Scale to Frame size" or "Set to Frame size"
Scale to Frame size: Will resize the media clip virtually at import - such that when added to the timeline at 100% it fits the frame.
Set to Frame size: Will set the media scaling dynamically using the effects control, such that at 50% (in your example) it fits the frame. Importantly - you can then rescale the media up on the timeline without loosing the original quality.
You can also use Clip > Video Options > Scale/Set ... (with clips selected in the Media Library or Timeline) to rescale clips in the manner stated above.


text:
How to duplicate composition and subcompositions?
I have a composition "A" with subcomposition "B". When one duplicates composition "A" to "A2", then both reference to the same subcomposition "B". I need that they reference independent subcompositions. How can I achive this?

This is what I tried

I followed the instructions from

clicked Ctrl+D to duplicate Layer A and B
selected copy B2 and reference B from A2, clicked Ctrl+Alt+/ to replace, but didnt work ( I have a german keyboard, maybe this shortcut doesn't work, because nothing happend.)

Also I simply tried to follow Copying All Settings Of One Composition in AE by just duplicating "B" to "B2" and inserting "B2" in "A2". However I also need that "B2" has the same transform and masksettings as "B" in composition "A2". If I select the transform settings, press Ctrl+C, click on reference "B2" and press Ctrl+V nothing happens. It seems that I can't copy the settings.
I am using Adobe After Effect 2015 CC

Make all your duplications in the Project Panel, not in the Layer/Timeline panels.
Duplicate Comp A
Duplicate Comp B
Double click Comp A2 to open it in the timeline.  It will still contain Comp B. We need to fix this.
Make sure Comp A2 is still open and visible in the timeline
Select Comp B 2 in the Project Panel
Select the Comp B layer in your Comp A 2 timeline
Hold down the option key on a mac (alt on a PC)
Drag Comp B 2 from your Project Panel over the top of Comp B in your timeline panel.
Let go of the dragging.
Comp B in your timeline panel should now be replaced with Comp B 2.
This is a bit of a faff, but gets easier after you've done it a few times.

Thank you. I think you mean "Select the Comp B layer in your Comp A2 timeline", right?

You’re absolutely right. Fixed it.

It's actually alt on a PC, it's option on a mac.

Fixed - thanks. Always get that confused

I wrote a script to do this automagically, with the option of recursing into all the sources of the precomps, to enable totally independent versions.
Available free on my blog here. Full disclosure: the software is completely free and open source, I wrote it for my own use and don't get anything whether or not you choose to install it.

Unfortunately it's broken... Doesn't work in newer version. Unable to execute script at line 9. scriptName is undefined


text:
How to slice a video at camera angle changes
I have a long live feed recorded.
It has different camera angles switching after one another but unpredictable timing.
The cameras do not zoom or move so what is recorded has parts that don't change that could be used to identify camera angles. There should be a way to cut the film into small segments and group them by angle.
I could do this using iMovie by hand but that would take forever as I would like to do this for many hours of this live feed.
Is there a way to do this using some free software?

https://pyscenedetect.readthedocs.io/en/latest/ seems like a free option, if it works ill write it as an answer...

It works but doesn't seem to correctly slice it

To almost perfectly slice it I used davinci resolve but that makes exporting the small individual scenes not viable. I think from there I will somehow copy the time of the scene changes and use another program to cut it.

To correctly detect the scene changes (almost correctly some changes were still not detected) I used Davinci Resolve. Then I had to type the wanted scene's start frame and end frame into a program that automatically cut it.
From Davinci Resolve it was extremely hard to copy the frame numbers as they could not be selected. I am sure there is a better way of getting the start frames and end frames from Davinci Resolve but I couldn't find it.
The cutting can be done using ffmpeg:
ffmpeg -i example.mp4 -vf trim=start_frame=10:end_frame=50 -an -fflags +genpts output.mp4
But it takes really long to get a clip from the end of a long movie for example.
It can also be done using applescript and that is much faster:
tell application "QuickTime Player"
    activate

    set startFrame to 84361
    set endFrame to 84452

    set fps to 23.976

    set startTime to startFrame / fps
    set endTime to endFrame / fps

    set inFile to "Users:me:Documents:folder:infile.mov"
    set outFile to "Users:me:Documents:folder:outfile.mov"

    try
        set theOpenedFile to open for access file outFile with write permission
        set eof of theOpenedFile to 0
    end try

    open file inFile
    trim front document from startTime to endTime
    export front document in outFile using settings preset "1080p"

    try
        close access theOpenedFile
    end try

    close every document saving no
end tell


text:
GoPro Fusion extended recording?
The Goal
I am looking at purchasing a GoPro Fusion in order to record a group of people gaming. The games will last for between 3 and 6 hours. I'm looking at the fusion because of how very unobtrusive it can feel relative to something like a multi-cam setup.
The Question
Is it possible to create a setup for the GoPro Fusion or a competitor that will record for that kind of duration?
Additional Notes
We will be in my home. I will therefore have access to pretty much anything I can afford: wall power, computers, wifi control, etc.

This is very straightforward to set up, yes. Because you can fill up SD cards very quickly with the resolutions these are capable of, you could run one at 1080p for longer duration, but that's still not going to stretch to 6 hours.
For that length of game you will want to have it connected via USB to a PC of some kind recording the video feed directly to disk, and providing power.
Relatively simple - and in fact using the default software that comes with the GoPro Fusion, you can pretty much do that out of the box.
As the Fusion has voice commands, that can also make for a very unobtrusive recording station.

OMG squee! Thanks! I felt like that sort of feature should be possible, but after reading waaaay too much documentation I still hadn't found that feature listed. Thanks!

Initially when I was looking at GoPros for long recording sessions, I went down the route of low resolution, and then low frame rate (which potentially is something you could look at, depending on the kind of game), but connecting to a PC and using it to record solves your data capacity issue.


text:
Does rule of thirds apply to videos?
I recently learned about rule of thirds in my photography class and it's really cool. But how can I take this technique and apply it to a video?

There are no hard rules, there are conventions. Whether to use them is totally up to you.

It is basically the same.
In a movie, you should have a motivated camera.
Meaning that the camera itself has or delivers an emotion.
A simple example:
Place someone really small into a corner of the screen, darken the lights. The person will look depressed and pushed to the edge from society.
Place someone in the entire frame into the middle and film them slightly from below and they will look powerfull and important.
You don't need to allways use rule of thirds in film, but you should consider it.
For example bringin an emotion into walking scene:
Person in right thirds, walking to left; Looks like the person walks into an open world
Person in right thirds, walking to right; Wlaking against a wall, not comming further...
There can be much meaning hidden inside a camera framing/move

Agree.  Yes, rule of thirds applies, but it's far from the only "rule" when it comes to video.  See also 30º rule and 180º rule which have less to do with framing and more to do with how a camera's position affects temporal edits.  Also, shooting for mixed aspect ratios is a big consideration in video.  "Every Frame a Painting" has some good videos on youtube about film composition.


text:
Are most scenes in movies voiced over in post production?
In this B roll of Harry Potter, one can see how the same scene (how they walk out of the water and up a hill) is filmed multiple times.
I guess that the final scene will be made up by several of these takes, and they will be cut (for example, the first part of the scene is made from take #1, and the second part is made from take #3).
If they cut within a scene, the audio will be cut, too.
How do movies deal with such situations?
Is the final (cut / edited) scene voiced over by the actors?

It's generally preferred to use the actual dialog audio from the take.  It matches the movement of the lips, it sounds right for the environment, the actor is giving an authentic performance, etc.  And, you don't have to pay the actor to come back for an extra day re-recording audio in a rented sound booth.
"Looping" in audio after a scene is shot is certainly not unheard of.  If a line needs to be changed, or there was an error on set, or there was some unavoidable noise going on during filming.  It'll also happen in very wide shots where it's hard to get a microphone close to an actor.  If this happens, it's called ADR -- Additional Dialog Recording, or sometimes Automatic Dialog Replacement.  Though as common as that latter definition of the acronym seems to be, the process really isn't particularly automated.
As for how to avoid needing it, you want to record clean sound from the start.  This is why you'll have a boom operator pointing a boom mic on a pole as close to the actor as possible -- even at the risk of accidentally getting the microphone in the shot.  If they kept the microphone far away, the actor would be quieter relative to all the other sounds going on in the room, so you'd have to crank up the gain and get more of those other sounds.  You can also have the actor wear a hidden lavalier microphone.  It's usually poking out near the collar close to their mouth, and then the wire runs inside the costume shirt so you can't see it.  Occasionally if the character has a big hat or helmet, a lav mic can be hidden in there instead of by their neck.
While you are in the location, you also record some "room tone."  Whatever the room sounds like when it's quiet -- because no place is actually 100% quiet.  There's some wind, or the neighbor's air conditioner or the house creaks slightly.  Whatever.  Get a few minutes of that.  And, if you have any crowd or whatever, you can get some of them talking or walking, or whatever it is that the other people are doing while the main characters are talking about the plot.
Then, when you get to editing the scene, you have a track of that "silent" room tone as a background noise.  And you have you crowd noise.  Maybe you use some actual recordings of the crowd from the set, maybe you just wind up using some stock sound, or do a separate audio recording session.  If it's a cafe or something, you'll have some clinking cups and dishes and silverware, and some babble of people "talking" but you want to make sure that it's not any recognizable words that would catch your ear while you are supposed to be paying attention to what the main characters are saying.  That can be just two or three tracks, or a whole bunch of tracks.  If you are on a space ship, you may have a bunch of tracks of engine sounds and beeping sensors and whatnot.  This bed of sound is constant through your scene, and is pretty much independent of the main character dialog that you get from the actual editing.  (Unless the sensors need to beep extra loud when the aliens approach or whatever, that sort of thing obviously needs to be in sync with the video.)
With that quiet but consistent bed of audio, you can cut the scene and get the best takes, and use the dialog audio from the relevant takes without to much trouble.  You don't notice any slight shifts in the audio from cut to cut because there is enough other audio that's consistent in that quiet background noise that it doesn't matter.

Thank you. Can you still take a look at the youtube scene that I mentioned? I don't see a microphone there. Can you tell me what you think how they did it?

They may have been using lavalier (lapel) mics.


text:
How to range-check luma in After Effects?
Where do I find the luma range clip indicator that I have in Final Cut?

You can add a new adjustment layer at the top of your composition, with the Levels effect set to the following:

Input Black: 254
Input White: 255

This will have the result of causing any luma values that were below 254 to become black, while anything above it becomes white. Here is an example of it over a fractal noise pattern:
Before

After

I don’t think there’s a way to get zebras on your output, but the Lumetri Scopes will give you a video signal that will show you whether your luma is too high.
https://www.premiumbeat.com/blog/color-correcting-video-lumetri-scopes/

Unfortunately, they're not helping. I need to know exactly where in the image the luma is clipping. I have demonstration-videos shot on white background and I need to make that background be absolute white (255,255,255).

I would adjust the levels on the shot until I can see that the Luma levels are at absolute white on the scopes.


text:
Sony Vegas VS After Effects for graphic / Keyframe editing
I want to animate "drawings" on people's faces like " X "'s and other lines and I am aware, as far as I know, that in sony vegas that is done via individual frames.
Is there another way? Does AE do it more easily?
As a general question which software is best used for editing or should a combination of software be used e.g Sony Vegas for final cut edits and then AE for post and graphic editing?

After Effects is definitely the right tool to use rather than Vegas for motion tracking / drawing on moving footage. Here is a classic tutorial that you can watch to get a sense for how to achieve face tracking & replacement.
Vegas is much better suited for editing. After Effects can often struggle to achieve real-time playback over extended periods of time and doesn't have the tools built in the same way as a NLE like Vegas, Premiere, or Avid.


text:
Premiere Pro sequence to Audition. Apply effect to all clips originating from one native video file
:)
I have a Premiere Project with several clips (interview) that originate from 1 video file. The clips are on different tracks (because messy workflow). However, in that clip is a noise air conditioner, I want to apply a multi-compressor to. I exported the sequence to Audition.
How can I tell Audition to apply the effects for CLIP1 to all CLIPn, since the AC is in all of the partial clips across the entire sequence and in different tracks. Basically find all clips that originate from the video file and apply effects to all of them.
Thank you!

Don't apply the effect to the clip. That way lies madness. If all the clips were on the same track then you'd add the effect to that track, but since as you've said the clips are on separate tracks you need to send those tracks to a bus, and then apply the effect to the bus before sending that bus to the master track.
A bus is like a pre-mix, it's useful for grouping tracks with similar audio or audio that needs to be controlled together, or have the same effect applied, e.g. you might have one for all the dialogue, fx, or music. The ouput of a bus will go to your master track by default, but you could send it to another bus if you want and so on.
To make a new bus:
In the track editor window make sure that the inputs / outputs icon is highlighted

On one of the tracks, set the output to a new bus by clicking on the dropdown for the output (I always feel those arrows point the wrong way, but that's just me. It's the bottom one that says Master by default). Then set the output for all the tracks that have the problem to this bus.

You can also add a bus in the mixer panel.

To add effects to a bus / track
in the track editor window, make sure the fx icon is highlighted (next to the inputs/outputs one).
Click on the triangle in the effects rack for the track and choose your effect from the drop down (your list of effects will look different to mine, mine is full of every free VST plugin that money can't buy).

Similarly you can also do this in your mixer window, the UI is the same:


text:
increasing sequence resolution in premier pro
I am editing footage with a resolution of 1228x690 in Premiere Pro 2020. When I tried to upload it to youtube, it automatically got bumped down to 480p, significantly lowering the quality. I tried to increase the video preview width x height settings but it is capped at 690p. Is there a way to force the video to a "higher resolution" so it won't get lowered to 480p? Am I just trying to change the wrong settings? Thank you for helping.

Is the file you uploaded to youtube 480p on your machine? If not, the problem is at YouTube's end, not yours.

First variant. You can change "Frame size" in "Sequence Settings" (Sequence -> Sequence Settings) to more higher. You need to change them with saving proportions of your video frame.
To save 720p quality on youtube you should set amount of vertical pixels to 720 or more. With 1080p it should be 1080p or more.

Second variant. You can change resolution of your video file on the render stage.
Move to Basic video settings, then uncheck checkbox for changing resolution. And then you can change it to needed. With height to 720p or more.
Also you can save proportions of frame.


text:
Tool to make a short youtube video
I'm a total newbie into developing videos..:) But I would like to create an animated video which is about 5-7 minutes long. The kind of ones we find on youtube.
I did some research to find a tool. I came across online tools like moovly and Animaker. They're easy to use..but their free version has limited features and with the free version you can only have a video length of 2 minutes.
I also stumbled upon the free tool called Blender. But unlike Moovly or Animaker, it seems it requires quite some knowledge in animation to make animation videos in Blender(don't know if I'm right. Just that I feel so..)
Is there a free online tool like Moovly or a software to download like Blender that will help me to easily make an animated video of about 5-7 minutes length which will also allow me to include voiceover and also facilitate adding of some of my custom images (from my desktop) into that animated video..?

The kind of ones we find on youtube

Well, youtube is a pretty big place, so you can find a lot of different animations, with different levels of complexity... really different levels in complexity.
Even the two online tools you posted are quite different. One is for 2d animations, and the other is more like a video editor. But the most important thing is that those tools have assets, one has animated toons, the other has a library of video clips.
This means that if you use another tool, which I will put a link to, you need to either create your own assets or get them from somewhere else. Video Clips, Music, still photos, cartoons, or even animated cartoons.
Sayed that, two great and free tools are:
HitFilm Express which is a video editor and a compositor (the compositor is the tool to make basic animations)
And NHC Express animate.
Here is a link to the graphic design forum post I made some days ago, explaining a bit more about them:
https://graphicdesign.stackexchange.com/questions/136912/free-and-easy-to-use-tool-for-easy-2d-animations/136917#136917

But you can not go as blindly as I feel you are going. You need to define what you really need. Video editing, 2D animation, a slideshow converted into a video...

Thanks a lot for the answer @Rafael...and thank you so much for the links to the free tools also...:) Being a beginner into this whole subject, I have a doubt...there is also this free online tool called Headliner. Is HitFilm Express a tool like that..?

On HF you can add text, photos, audio or video. "Like that" is again too board, define specific tasks you need.

Ok..@Rafael..Thanks...

Actually what I wanted was to add some images or animations to my voice..


text:
Is there any way to make text transparent when it is in a shape and make non-transparent when it is outside the shape?
I am a beginner in After Effects. I came to know the TrkMat - Alpha Inverted Matte "Text" option to make the text transparent within a shape like the below image.

But when I move the text outside of the shape, it will stay as transparent.
Is there any way to make the text non-transparent when moving out of the shape like the below image?

So that when an animation occurs, the text will be non-transparent at first and the portion going inside the shape will become transparent immediately. Please help me to know if I can do this. I couldn't find any solution from the internet.

It's harder to do than it should be, I guess because AE is layer-based rather than node-based like Fusion etc.
You're going to have to make a copy of both of your layers, parent each copy to the original layer – so you only have to move one of each – and arrange them so that your layer stack looks like
text
solid
solid
text

(or vice versa). Now make the bottom solid a track matte for the text layer, using alpha-inverted, so that the text is only visible where the solid isn't, and make the top text the track matte for the top solid, once again using alpha -inverted, so that it punches a hole in the top solid layer. The top solid will form the left hand part of the design and the bottom text the right side.
You could also use just the original layers and have one of them use difference mode, pre-comp them both and then use a extract effect to turn the black parts into transparency, but you'll then have to do the animating in a separate comp, which can make it harder to work with.
There is also the Set Matte effect. A lot of people struggle with this effect, it's a lot less intuitive than the slightly more complicated solutions above, so you'll have to do some research. A good explainer video here.

Thanks a lot and that worked like a charm.


text:
Fill a shape layer with a pattern (repeating image) in After Effects
In a Shape Layer I have managed to build myself the following shape, which is basically a circle and a rectangle:

I wish to fill that shape with folk-attern.png (repeating) so that it covers the whole thing. Is that doable?
I can't see an option that would allow me to fill the shape with an image!

Shape layers don't have the ability to use a bitmapped fill. What you need to do is use the shape layer as a matte for the fill pattern.
To make a repeating pattern from your image, bring it into the comp as an image layer. Now apply the CC RepeTile effect (it's an included effect with AE in the Stylize folder).

Increase the numbers in the expand right, expand lef, expand up, and expand down sliders until the pattern fills the space you want it to occupy. You don't have to worry if the original layer is too small, this effect will increase the bounds of the layer beyond its original size.
Make sure the image layer is below your shape layer and set its matte to alpha matte "Shape Layer 1" (or whatever your shape layer is called). If you can't see the matte column hit f4.

If you want the pattern to transform with the shape layer, set it as the parent of the fill layer (or vice versa), so that when you move, scale, or rotate one, the other will follow.

Thank you very much, that worked!

is there a way to change the opacity of the pattern?

Use the opacity control on the opacity layer. Or the matte layer for that matter. Hit 't' to bring it up.


text:
After Effects What does this Icon mean
Thanks in Advance,
Can someone help with explaining what this Icon mean couldn't find any reference,
cheers

It's called a slip-edit (see Adobe's explanation here).
If you have the Pan-Behind tool selected, when you see this icon over a clip, it means you can drag the clip left or right in time, and the start and end points of the clip will change, but the position and duration in your timeline will stay in the same place.  It's just like doing a slip edit in Premiere.

Thank you so much appreciate the help cheers


text:
Remuxing a TS file to MP4 results in a less fluid video
I'm trying to convert a .ts file to an .mp4. I'm using the following ffmpeg command:
ffmpeg -i all.ts -c copy all.mp4

This results in a noticeable loss in the fluidity of the video, which looks much more fluid in the original .ts format when viewed in VLC.
Output of ffmpeg:
Input #0, mpegts, from 'all.ts':
  Duration: 00:00:25.00, start: 235.000000, bitrate: 804 kb/s
  Program 16727
    Stream #0:0[0x22]: Audio: aac (LC) ([15][0][0][0] / 0x000F), 44100 Hz, stereo, fltp, 124 kb/s
    Stream #0:1[0x21]: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(progressive), 960x540 [SAR 1:1 DAR 16:9], 25 fps, 25 t
br, 90k tbn, 50 tbc
File 'all.mp4' already exists. Overwrite ? [y/N] y
Output #0, mp4, to 'all.mp4':
  Metadata:
    encoder         : Lavf58.29.100
    Stream #0:0: Video: h264 (Main) (avc1 / 0x31637661), yuv420p(progressive), 960x540 [SAR 1:1 DAR 16:9], q=2-31, 25 fps, 25 tbr,
 90k tbn, 90k tbc
    Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 124 kb/s
Stream mapping:
  Stream #0:1 -> #0:0 (copy)
  Stream #0:0 -> #0:1 (copy)
Press [q] to stop, [?] for help
[mpegts @ 0x7fabfe802a00] Invalid timestamps stream=1, pts=21153600, dts=21160800, size=1936
[mpegts @ 0x7fabfe802a00] Invalid timestamps stream=1, pts=21160800, dts=21164400, size=2827
[mp4 @ 0x7fabff005000] Invalid DTS: 10800 PTS: 3600 in output stream 0:0, replacing by guess
[mp4 @ 0x7fabff005000] Invalid DTS: 14400 PTS: 10800 in output stream 0:0, replacing by guess
...
frame=  625 fps=0.0 q=-1.0 Lsize=    2330kB time=00:00:24.98 bitrate= 764.0kbits/s speed= 614x
video:1908kB audio:398kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.070788%

There's lots of Invalid timestamps and Invalid DTS errors, but I'm not sure they're related to the problem.
I've uploaded a small sample to demonstrate the error: here is the original TS file, and here the not-so-fluid MP4 result.
Any idea of how to fix this? I have noticed that the problem does not occur if I re-encode the video track with h264, but I'd really like to just remux as the original TS looks just fine.
Thanks!

There's lots of Invalid timestamps and Invalid DTS errors, but I'm not sure they're related to the problem.
They are, frames in video streams with B-frames are not encoded or stored in presentation order, so the presentation timestamps have to be correctly offset for fluid playback. In this TS sample, you have presentation timestamps earlier than decoding timestamps, which are invalid, and ffmpeg defaults to assigning the DTS as the new PTS.
Instead, use existing PTS as the reference.
ffmpeg -fflags +igndts -i all.ts -c copy all.mp4

Sorry to butt in, but is there a way to ignore/hide the [mpegts @ [...]] Invalid timestamps [...] messages as well? That way, while downloading a HLS videostream, I'll only get to see the desired [https @ [...]] Opening 'https://[...].ts' for reading.

No, warnings and errors have more priority than informational messages.


text:
How do I change the length of the timeline of the composition to only be as long as my video footage?

How do I reduce the length on the Time Ruler in order to make the composition shorter in duration?

You can do what @stib said. Use the B and N shortcuts to set the beginning and end of the work area to match your footage. Another good shortcut is  Shift and X to cut the timeline to the current work area.

There's no built - in function that does it, but there's a script for that. I wrote one called first-n-last, it's available (free, open source) here https://blob.pureandapplied.com.au/
Alternatively, park your playhead at the beginning of the first layer (select that layer and hit i), then set the start of the work area to that frame by hitting b then select the last layer and hit go to the last frame (hit o) and set the end of the work area to that frame by hitting n. Now right click the work area and choose trim comp to work area from the contextual menu. This doesn't work for layers that extend beyond the beginning or end of the comp, but my srcipt does.

You have a really nice website! I'll try it out and get back.


text:
How do I record video on my computer using a (mirrorless) camera as the video source?
I want to record video on my computer using my Canon M50 as the video source. It's similar to how one might use a webcam instead of the camera integrated into their computer. The only difference is that I want to create videos, not stream.
Any ideas?

There are some options, but I am not sure what would work on your specific camera.
If your camera has an HDMI direct output you could use one HDMI to USB converter, one I know that works well is ElGato.
But here is the issue, you need to test if your camera sends a clean HDMI signal, this is without any menu, timestamp, configuration, etc. Test this connecting the camera to any TV.
Another thing to consider is the time the camera remains transmitting, for example, if it is not recording. It could just turn off in the middle of the transmission.
You can also try a tethered software that can use live view mode. The problem here is that the camera will transmit a Still Image size, for example, an 6000x4000, so the the result could be at an extremely low frame rate.


text:
Does any software have the capability to create a mask/alpha value based on the volume of an audio channel
I'm looking for an automagical way to create a Google Hangouts effect, ie.
 1. I have a number of files that are recordings of individual conversation members.
 2. I want to put together the video tracks into one project, and mask each one when the corresponding audio is silent (below some threshold), and to make it visible when there is audio from that audio track (so basically how Skype/Hangouts looks -> someone is talking, you see their webcam)
I haven't been able to find something like this using Google, or poking around in Premiere and Lightworks, but if it's available in another program, that would be great to know.
The mask doesn't need any motion tracking - either the entire screen is entirely transparent (audio), or entirely opaque (no audio).
Is there any way to do this automatically, or is it something that has to be manually put together?

You could certainly do it in After Effects. If you convert the audio levels to keyframes you can then use expressions / the pickwhip to drive the opacity of the layers. After Effects is not free. I wouldn't be surprised if it was possible in Fusion (freemium) and certainly other compositing tools like Nuke or Apple Motion. Natron, (free) may have the capability. There was an audio to ascii plugin, I don't think it still works though.
You could do it in Blender, because of course you could do it in Blender. Blender is free.
For a more programmatic approach you could use something like Processing or OpenFrameworks (free). You need Java or C++ knowledge to use these.
It is definitely possible in all of these programs, though in none of them is it a beginner-level operation. The simplest workflow would probably be After Effects, though that might be my bias because it's the one I know best.

Perfect, I was missing the step to first go to keyframes when I was googling this. Thank you!


text:
ffmpeg conversions lead to incorrect time on vlc
I am converting a video using the following:
$ ffmpeg -y -analyzeduration 2147483647 -probesize 2147483647 -i /home/michael/Desktop/transcodingtemp/output.mkv -max_interleave_delta 0 -filter_complex "[0:v][0:s:0]overlay[v1];[v1]scale=w=-2:h=720:flags=gauss[v2]" -max_muxing_queue_size 1024 -map "[v2]" -map 0:1? -map 0:2? -map 0:3? -map 0:4? -max_muxing_queue_size 9999 -codec:v:0 libx264 -crf 23 -c:a aac -b:a 320k -sn /home/michael/Desktop/transcodingtemp/output.mkv_transcoded.mkv
ffmpeg version 4.2.2-1ubuntu1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-3ubuntu1)
  configuration: --prefix=/usr --extra-version=1ubuntu1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, matroska,webm, from '/home/michael/Desktop/transcodingtemp/output.mkv':
  Metadata:
    ENCODER         : Lavf58.29.100
  Duration: 00:05:00.11, start: 0.000000, bitrate: 3243 kb/s
    Chapter #0:0: start 0.000000, end 159.493000
    Metadata:
      title           : Chapter 01
    Chapter #0:1: start 159.493000, end 300.000000
    Metadata:
      title           : Chapter 02
    Stream #0:0: Video: h264 (High), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
    Metadata:
      BPS-eng         : 1368113
      DURATION-eng    : 01:38:24.941000000
      NUMBER_OF_FRAMES-eng: 141577
      NUMBER_OF_BYTES-eng: 1009828723
      _STATISTICS_WRITING_APP-eng: mkvmerge v34.0.0 ('Sight and Seen') 64-bit
      _STATISTICS_WRITING_DATE_UTC-eng: 2019-06-07 05:38:49
      _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
      ENCODER         : Lavc57.107.100 h264_vaapi
      DURATION        : 00:05:00.112000000
    Stream #0:1(jpn): Audio: aac (LC), 48000 Hz, 5.1, fltp (default)
    Metadata:
      BPS-eng         : 310439
      DURATION-eng    : 01:38:24.938000000
      NUMBER_OF_FRAMES-eng: 276794
      NUMBER_OF_BYTES-eng: 229141045
      _STATISTICS_WRITING_APP-eng: mkvmerge v34.0.0 ('Sight and Seen') 64-bit
      _STATISTICS_WRITING_DATE_UTC-eng: 2019-06-07 05:38:49
      _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
      ENCODER         : Lavc57.107.100 aac
      DURATION        : 00:05:00.010000000
    Stream #0:2(eng): Subtitle: hdmv_pgs_subtitle, 1920x1080 (default)
    Metadata:
      title           : English Sub (Translated from Japanese)
      BPS-eng         : 17619
      DURATION-eng    : 01:35:43.029000000
      NUMBER_OF_FRAMES-eng: 2298
      NUMBER_OF_BYTES-eng: 12648785
      _STATISTICS_WRITING_APP-eng: mkvmerge v34.0.0 ('Sight and Seen') 64-bit
      _STATISTICS_WRITING_DATE_UTC-eng: 2019-06-07 05:38:49
      _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
      DURATION        : 00:04:54.440000000
Stream mapping:
  Stream #0:0 (h264) -> overlay:main (graph 0)
  Stream #0:2 (pgssub) -> overlay:overlay (graph 0)
  scale (graph 0) -> Stream #0:0 (libx264)
  Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[matroska,webm @ 0x5571480cfb80] sub2video: using 1920x1080 canvas
[libx264 @ 0x5571480fdf40] using SAR=1/1
[libx264 @ 0x5571480fdf40] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0x5571480fdf40] profile High, level 3.1
[libx264 @ 0x5571480fdf40] 264 - core 155 r2917 0a84d98 - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=23 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, matroska, to '/home/michael/Desktop/transcodingtemp/output.mkv_transcoded.mkv':
  Metadata:
    encoder         : Lavf58.29.100
    Chapter #0:0: start 0.000000, end 159.493000
    Metadata:
      title           : Chapter 01
    Chapter #0:1: start 159.493000, end 300.000000
    Metadata:
      title           : Chapter 02
    Stream #0:0: Video: h264 (libx264) (H264 / 0x34363248), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 23.98 fps, 1k tbn, 23.98 tbc (default)
    Metadata:
      encoder         : Lavc58.54.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1(jpn): Audio: aac (LC) ([255][0][0][0] / 0x00FF), 48000 Hz, 5.1, fltp, 320 kb/s (default)
    Metadata:
      BPS-eng         : 310439
      DURATION-eng    : 01:38:24.938000000
      NUMBER_OF_FRAMES-eng: 276794
      NUMBER_OF_BYTES-eng: 229141045
      _STATISTICS_WRITING_APP-eng: mkvmerge v34.0.0 ('Sight and Seen') 64-bit
      _STATISTICS_WRITING_DATE_UTC-eng: 2019-06-07 05:38:49
      _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
      DURATION        : 00:05:00.010000000
      encoder         : Lavc58.54.100 aac
[matroska @ 0x5571480fc080] Starting new cluster due to timestampte=1026.8kbits/s speed=2.92x
    Last message repeated 1 times
frame= 7075 fps= 69 q=-1.0 Lsize=   38040kB time=00:05:00.01 bitrate=1038.7kbits/s speed=2.91x
video:26400kB audio:11493kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.388885%
[libx264 @ 0x5571480fdf40] frame I:57    Avg QP:14.50  size: 67869
[libx264 @ 0x5571480fdf40] frame P:1978  Avg QP:18.64  size:  8377
[libx264 @ 0x5571480fdf40] frame B:5040  Avg QP:24.34  size:  1308
[libx264 @ 0x5571480fdf40] consecutive B-frames:  3.2%  3.8%  5.1% 87.9%
[libx264 @ 0x5571480fdf40] mb I  I16..4: 32.8% 45.8% 21.5%
[libx264 @ 0x5571480fdf40] mb P  I16..4:  2.5%  5.9%  0.9%  P16..4: 16.6%  7.0%  4.4%  0.0%  0.0%    skip:62.7%
[libx264 @ 0x5571480fdf40] mb B  I16..4:  0.2%  0.3%  0.1%  B16..8: 14.6%  1.0%  0.1%  direct: 0.7%  skip:83.0%  L0:42.8% L1:52.9% BI: 4.4%
[libx264 @ 0x5571480fdf40] 8x8 transform intra:58.7% inter:71.8%
[libx264 @ 0x5571480fdf40] coded y,uvDC,uvAC intra: 36.5% 56.5% 28.2% inter: 3.8% 5.5% 0.4%
[libx264 @ 0x5571480fdf40] i16 v,h,dc,p: 46% 30%  5% 20%
[libx264 @ 0x5571480fdf40] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 26% 19% 25%  4%  6%  5%  6%  4%  4%
[libx264 @ 0x5571480fdf40] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 25% 23% 16%  5%  7%  7%  7%  5%  5%
[libx264 @ 0x5571480fdf40] i8c dc,h,v,p: 52% 23% 19%  6%
[libx264 @ 0x5571480fdf40] Weighted P-Frames: Y:9.3% UV:5.3%
[libx264 @ 0x5571480fdf40] ref P L0: 71.0% 14.0% 11.2%  3.7%  0.1%
[libx264 @ 0x5571480fdf40] ref B L0: 91.6%  6.8%  1.6%
[libx264 @ 0x5571480fdf40] ref B L1: 96.6%  3.4%
[libx264 @ 0x5571480fdf40] kb/s:0.03
[aac @ 0x55714810e580] Qavg: 3812.204

The problem is that when I check the video, I get on VLC an incorrect max time 1197 hours. I know the problem is caused by the overlay (filter_complex) but don't know why. I also tried just "-filter_complex "[0:v][0:s:0]overlay[v1]" but even produces the same result.

2 Things:
1. why do you only convert the 0 stream? you could just do -c:v libx264 (instead of -codec:v:0 libx264)
2. you could try to use the shortest statement in your overlay-statement. Like this [0:v][0:s:0]overlay=shortest[v1],
See here for more:
https://ffmpeg.org/ffmpeg-filters.html#overlay-1
https://ffmpeg.org/ffmpeg-filters.html#framesync
You could also try reencoding your transcoded video without filters and see if you get errors or if the time is fixed after that.
Greetings
(This is posted as an answer and not a comment, because I can't comment)

Shortest solved it. I set it to shortest=1. But I am not sure why shortest fixes it.

Probably one your videos is extremely long, or the overlay filter has issues with overlaying the subtitle stream and keeping the timestamps intact. Eitherway usually in an overlay you don't want to run one stream, while the other already ended. The shortest flag just tells the filter to stop when the first stream ends and discard the remainder of the other streams.


text:
Do I need to configure CUDA in my graphics card for using CUDA support in Pinnacle studio?
The title explains a lot. Still, I wanted to ask in order to use

If CUDA is supported by your graphics card it should be enabled by default.
To confirm:

Open NVIDIA Control Panel.
Check that CUDA is enabled in global settings.

Check Application specific settings. Make sure that Pinnacle Studio is selected in the drop down list (where I have Chrome in my example screenshot)
Then make sure Pinncale uses global settings, or directly enable CUDA
finally check if Pinnacle has it's own CUDA settings (I don't know about that.)
if you have still problems, you should contact Pinnacle support


text:
Compressing video recording- file gets bigger!
i have recorded a part of my screen (2624x1714, 8 hours, ca. 30 GB), then trim and cut in final cut pro. Now I want to compress it with Compressor. I set the output to HD 1080p but the file doesn't get smaller but bigger (36GB). Why? How should I proceed?
Thanks
L

What are the codecs, bit rates and frame rates of the original and the final videos? The end format will have half the pixels of the original, so if it's larger in file size its bit rate must be twice as high (simplifying).

okay i solved it by reducing the bit rate thank you

I solved it by reducing the bitrate
thank you


text:
Preview Aspect Ratio on Camera LCD Screen
I am planning on shooting a short film with my DSLR (Nikon D5300). I want the film to be in 2.39:1 (1920x800), but my camera is recording in 16:9 (1920x1080).
I wondered if there is any way to preview the final aspect ratio on the camera's LCD screen so that I better see what will be in the frame (since the cropping will be done in post-production and I don't want unhappy surprises like being to close to my actor and then half of their head gets chopped off). I thought about building some sort of box thing with the corresponding bars on top and bottom of the frame that I can put on the screen, but this would be rather bulky.
Are there any solutions to preview the aspect ratio on the camera's LCD screen?

Apply a screen protector to the LCD and use a permanent marker to draw the aspect ratio you want to frame for. Relatively inexpensive, easy to add, and completely safe for your screen. You may want to just draw a fairly thin line to mark the safe area; it can sometimes be useful to see the full frame.

I assume you already checked the manual and there's no firmware option.
Well, the easiest way is to hide the excess areas with black electrical tape that you put directly on the screen after measuring the frame height. If needed the tape can be pulled partly off and put back on.
The pricy alternative is a suitable external monitor, called "field monitor".

Literally masking the display with tape is a good suggestion, but you might want to use something other than electrical tape. Electrical tape tends to leave adhesive residue when removed. Definitely don't use duct tape. While it probably comes off cleaner, the adhesive on gaffer's tape is a bit too aggressive for me to put on my own LCD. Maybe a paper tape of some kind?

Good point. Tapes vary, sometimes residues will only remain if the tape has been sticking for many hours, sometimes it's there immediately. Paper tape might be safer indeed. Sticky residues can be cleaned with isopropanol if the LCD screen is waterproof.


text:
Resolve - Blur the edges of an inserted clip
I am totally new to DaVinci Resolve. I have included a small video on top of another footage, in the bottom right corner. How can I blur the edges of this inserted video?
I am able to blur the content of the video, what is inside, but I would like to blur the edges/border of the small video, so it blends better on top of the other one.

I found the answer:

Go to Color at the bottom.
Select the clip you want to modify (the small video on top).
Add your usual nodes as needed.
Right click and Add Alpha Output. This will create a new blue terminator.
Right click and add a new Corrector node and use the rectangle, ellipse, or whatever shape you need to define the transparent/opaque regions.
Connect the previous nodes to the recently created node. Now link the green and blue points. This will make an alpha channel, making the region you marked as transparent/opaque.
If you need to use the same ALPHA node in other clips, you can create a Shared node that can be reused in other clips. Instead of adding a Corrector node this time, use your shared node.

See the image below for a clarification:

Source:


text:
Can I export keyframe settings in OBS?
I exported my settings and got a file like this:
[General]
Name=Adobe RTMP

[Video]
BaseCX=1920
BaseCY=1080
OutputCX=1920
OutputCY=1080
ColorSpace=601
ColorRange=Partial

[Panels]
CookieId=CB44DC4848BD02DB

[Output]
Mode=Advanced

[SimpleOutput]
VBitrate=4000

[AdvOut]
VBitrate=4000
TrackIndex=1
RecType=Standard
RecTracks=1
FFOutputToFile=true
FFFormat=
FFFormatMimeType=
FFVEncoderId=0
FFVEncoder=
FFAEncoderId=0
FFAEncoder=
FFAudioMixes=1
RescaleRes=1680x1050
RecRescaleRes=1680x1050
FFRescaleRes=1680x1050

I know I had to add [SimpleOutput] myself, to ensure 4K bitrate for people using advanced or simple UI. I am wondering how I might be able to add a specific setting for Keyframe Interval. I want people to download my settings to have keyframe interval of 2, rather than auto (which is 8.3).

Yes, you can! In your streamEncoder.json add the following.
{
...
      "keyint_sec": 2
...
}


text:
How to mask a mp4 video with another alpha mp4 video
A noob question. I have two mp4 video files. The first one is ordinary color video (right side).
The second one is transparency mask video (alpha), it's a mp4 video not an image (left side).
This second video has gray-scale colors, and it changes frame by frame. This second video has no alpha channel.

What video editor is able to mask the first color video with the second alpha video, so that the first video is rendered with its transparency changing frame by frame according to the second alpha video? And please a short explanation on how to do it?
I prefer a free editor, but if there isn't one, a proprietary editor doesn't matter.
Thank you.

Are you using a Mac or a PC?

@tomh I'm using a PC

If you prefer a free editor, Blender could achieve something like this. You need to look at the luma key nodes.
Blender is free but has a steep learning curve. Adobe Premiere could do this quickly using a track matte, but it's not free.
After Effects is also paid-software, and has a steeper learning curve than Premiere, but can also use track mattes - see the other answer for details.

Thank you, I'll give Blender a try.

This would be easy to do with After-Effects. Do the following:
Create a new composition with the settings of the mp4. You can drag it on the composition symbol to automatically create it.
Then, drag your alpha-mp4 above the color-mp4. Now, set the "track matte" to "Luma-Mask" from the alpha-mp4. This should be all.

Thank you, I'll try it out once I have the After Effect.


text:
ffmpeg - Apply padding to input images while combining multiple images and audio track
I am using below command to create a slideshow using ffmpeg:
ffmpeg -r 1 -i IMG_%04d.jpeg -i audio.mp3 -c:v libx264 -c:a aac -pix_fmt yuv420p -r 24 -y output.mp4 -vf pad=ceil(iw/2)*2:ceil(ih/2)*2

I had to add pad=ceil(iw/2)*2:ceil(ih/2)*2 to make width or height even number because if one of the input image width/height is odd, ffmpeg throws error. Now my problem is; input images can be of different resolution and aspect ratio. I want to add padding (left/right or top/bottom) to all images to make them of equal size before they are converted into video frames. How can I achieve this in efficient way?
Edit:
It would be nice if I can specify output resolution and all images are either scaled down or up keeping their aspect ratio intact according to that resolution.

I have got it working through this way:
ffmpeg -r 1 -i image%4d.png -i audio.mp3 -filter_complex scale=w=%d:h=%d:force_original_aspect_ratio=1,pad=%d:%d:(ow-iw)/2:(oh-ih)/2 -c:v libx264 -c:a aac -pix_fmt yuv420p -r 1 -y output.mp4

This way aspect ratio of input images remain intact and also it solves odd image width/height issue. I hope this answer would help other users facing same issue.

If your output resolution is AxB, then your filters would be
-vf "scale=A:B:force_original_aspect_ratio=decrease,pad=A:B:-1:-1"

Getting this error in logs:
Getting Negative values are not acceptable. Failed to configure input pad on Parsed_pad_1. Error reinitializing filters! Failed to inject frame into filter network: Invalid argument. rror while processing the decoded data for stream #0:0

Are A or B odd values?

no, both are even like 720 | 1280

Add -report and share report.

Gyan, I have found the solution. You can review my answer.

It does the same thing as my answer.


text:
Changing duration of multiple After Effects layers at once
Can I set duration of multiple After Effects (freezed frame) layers to a fixes value (e.g. 4 seconds each) at once?

Yes.
Select all of the layers.  Move the time cursor to where you want the layers duration to end.  Press alt + ]. This will extend your layer to that position (if it is able to be extended).
Pressing alt + [ would adjust the in point
Pressing Press [ or ] on their own would move the in or out point of the layer to your current time position.

also if you're shifting layers around https://aescripts.com/pt_shiftlayers/ is v useful

Those freezed frame layers are distributed around my composition between non-freezed layers which I dont want to modify.

Perfect, thanks! I aligned all the freezed frame layers to the cursor using [, moved the cursor 4 seconds forward and used alt+[ to apply a single out point to all (and finally sequnced them using animation>keyframe assistant).


text:
After Effects melting film strip in the old projector
I want to make the effect of a melting film strip in the old projector. Please tell me how this can be done with After Effects? I have all the necessary footages, but after blending it does not look realistic. I want the film strip  to start melting from below, and then the fire gradually destroyed the frame and burst out.

I would try using a displacement map. You can use a solid with turbulent noise on it and use it as your map, then animate the evolution, contrast and brightness so it displaces the film accordingly. If your burn is a separate layer, you can also use this as the matte for the solid with turbulent-noise in it with the effect "set matte".
Also, you might want to try to using a similar turbulent noise layer as a matte for the whole comp, meaning that the spreading bubbles from the noise (you can spread it out by pulling up a mask and keyframing the mask expansion) effectively get shuffled into your alpha-layer. If you then duplicate all this, move it one layer below, shift it to the right in the timeline (so the lower layer is about 10 frames later than the upper) and then drastically increase the contrast and lower the brightness, you will achieve some dark edges to the burnt parts.

Thanks for the tip. A displacement map is a great solution, but I can't figure out how to move displacement along Z axis. I want the film strip to swell in the shape of a bulb before the flame appears.


text:
Help achieving a specifc effect in DaVinci Resolve - glowing floating head fades in and then out
Disclaimer:  I'm a total video newbie.  Until 4 days ago I had never used an NLE before or even heard the acronym.
I'm an experienced musician, and with much of the country shut down, an ex-bandmate and I have started making music together again.  We're working on a video for a rather silly cover.  The music is good, the song is silly, and we want the video to be silly too.  We are working with DaVinci Resolve, and I've spent a fair amount of time on the tutorials.  I think I have a decent command of how to use the tool, I just don't have the necessary familiarity with the many many many features to know how to do what I want...
What I want to do is to use a clip of my friend singing the lead vocal part, and then when his backup vocal part comes in, have just his head come into the scene, mouth the words "I love you", and then disappear.  Ideally it would fade in somehow and then fade out, and maybe even have a glow around it, as if it were some floating angelic being.  It could stay somewhat transparent and ghostly.
I did work through the Resolve tutorial on how to do basic effects work.  I was able to draw a shape around his head in the backing vocal clip and make the rest of the clip transparent.  Step 1 accomplished.  I'm sure I did it in a terribly inefficient way, based on the one effect that was introduced in the Resolve tutorial (delta keying, plus a mask that I drew, and then pulling wildly on controls until it did what I wanted...I'd love to know a way to just draw a shape and make everything outside of it transparent).  But in any case, step 1 done.  I have a floating head.
Step 2:  Change the position of that floating head.  I can't seem to do this though I could swear I've done it in the tutorial.  Would probably find this with enough time.
Step 3:  Give it a halo.  No idea how to do this.
Step 4: Make it fade into being and then fade out.  No idea how to do this.
It doesn't need to look perfect.  I'm not looking for complete answers.  But some guidance would be wonderful.
Thanks so much!

I found this helpful tutorial on basic compositing:

With this I was able to easily do additive compositing with a mask and I can easily adjust the position, opacity, etc.
I wanted a white glow, and as luck would have it the video was filmed in front of a white brick wall. It works great now.

While it seems quite handy to insert a video URL, it's obvious what the disadvantages are: The video is gone now! A better answer would be to summarize what you've learned from the video. Also on can search test easily, but you cannot search test in a video.


text:
Best strategy to keep aspect ratio consistent for all videos having any resolution
I am using the following ffmpeg command to create multiple resolutions for the same video content.
ffmpeg -i ${f} -c:v libx264 -keyint_min 150 \
-g 150 -profile:v main -f h264 -dash 1 \
-an -vf scale=640:360 -b:v 750k ${streamsdirectory}/${filename}_640x360_750k.mp4 \
-an -vf scale=1280:720 -b:v 2000k ${streamsdirectory}/${filename}_1280x720_2000k.mp4 \
-an -vf scale=1920:1080 -b:v 4000k ${streamsdirectory}/${filename}_1920x1080_4000k.mp4

What is the best strategy to keep respect for the aspect ratio for any video content ?

If you want the output resolution to be 1280x720 and the video keeps its original ratio aspect as well:
ffmpeg  -v error -stats -i input -vf
"scale=1280:720:force_original_aspect_ratio=1,pad=1280:720:(ow-iw)/2:(oh-ih)/2"
output

To keep aspect ratio change:
-vf scale=640:360
-vf scale=1280:720
-vf scale=1920:1080

to:
-vf scale=-2:360
-vf scale=-2:720
-vf scale=-2:1080

See scale filter documentation for more info.

How can I support both horizontal and vertical videos at the same time, say 1920x1080 and 1080x1920 ?

@UtkuBulkan See Resizing videos to fit into specific size.


text:
Are the EV principles that are used in photography the same in video production?
I am new to photography. I have been reading about the EV values and how to calculate them, with the f-stops, the shutter speed and ISO. However, I want to know if those same principles, tables and values apply not only for still photography, but for video shooting.
In summary, can I use the same tables that are used to calculate the EV (for still photography) for video shooting? Or do I have to take other variables into consideration (FPS etc.)
Thanks in advance
Marios
P.S. This is the original question I asked in the Photography forum of the site, I am reposting it here since a member of the other forum told me to post here.

Yes.  For things like exposure time, EV, f-stops, video is just the same as still photographs.  You just happen to be taking 24 or more of them per second.
The one difference in actually exposing a frame would be that still photography typically uses a mechanical shutter.  (You can hear it k'thwap when you take a picture on many cameras.)  But video uses an electronic shutter.  This could very slightly effect things like how motion blur looks, or how parts of the image are exposed over the course of the exposure time.  But that 99% doesn't matter, especially if you are just getting up to speed on the basics of things like f-stops.

Thanks for the answer!


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"Flashbacky" transition in Hitfilm
I have a small movie I'm making that is just a bunch of discussions and flashbacks to the past, I wanted to find an appropriate transition, that's like a flash transition. I saw a few ways to do that but they're hard to recreate all over again. Please, give me ideas for a transition like that that is easy to replicate, because i need to use it very often. Thanks!

The question is clear, but I'm missing a lot of context information. What do you mean with "Hitfilm"? What video editor do you use? You are probably using the wrong tool if a flash transition is too much work. Are you sure your concept has a chance to work? I mean if a short movie has so many flashback that transitions are too much work, it probably means you have planned way too many flashbacks.  How many flashbacks are there approximately? Maybe your telling your story wrong: think of your audience - don't you think that many flashbacks will confuse them? What kind of movie is that anyway?

@Matt, Hitfilm Express is a semi-popular NLE that, I think, predates Resolve being available for free. But, I agree, a flashback transition is probably a trope to be avoided.

I use Hitfilm Express, it's very similar to Premiere. And I can't really avoid the flashback, that's the whole point tand that's why asked the question.

Ah, sorry, I didn't know that editor. Well,it's your movie, your decision. I am sceptical but in no position to criticize your decision without seeing the result. It's just that I have my doubts.

A very simple one you can do is a transition that is dipping to white. If your editor doesn't offer this kind of transition you can do the following: add a still image which is all white, do a cross dissolve from scene A to the white still, then a cross dissolve from the white still to scene B. Ideally the first time you use it is when audience can infer clearly from context that scene B is a flashback, so that they recognize that this type of transition represents a flashback. Also you may add a subtle, short sound effect.
It does not look that fancy, but should be easy to do and many would argue anyway to keep your transitions clean and simple anyway.

Thank you very much! I oped for something similar, but with a circular iris instead of a cross dissolve.


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Windows not finding Kdenlive files
Recently I started creating videos for work, by using OBS Studio to record my screen. Today I downloaded Kdenlive (I run a Windows machine), and followed this tutorial.
Long story short, I am able to edit and render videos inside Kdenlive, I have also saved the project. However, when I try to find anything Kdenlive has produced, Windows cannot locate it.
A specific example:

I open directory X from Kdenlive, for example so as to open a project or add a video. There, I see the project (.kdenlive) and the video (.mp4). Video is playable (right click => Open with VLC...)
I navigate to and open the same directory from Windows. There is neither a .kdenlive project, nor a .mp4 video.

Even viewing the directory's Properties from Kdenlive and from Windows shows differences in size and file number. The same happens from e.g. GitBash (ls and du).
I've also tried to move the .mp4 (accessing it from Kdenlive) to another directory, which is also a Git project. The Git GUI does not find it either.
I could not find anything related in any forum (including this SE). My Kdenlive version is 20.04, and my Windows is set up to show hidden files and directories. Any help is appreciated, I can add images if needed.
Thanks in advance!

If anyone happens to have this problem:

from inside kdenlive, copy the video (even better: make a .zip and copy it)
also from there, navigate to a folder which is inside a Git project
paste the video or the archive there
still from inside kdenlive, open a Git Bash, then commit and push the pasted file
exit the file explorer and kdenlive
navigate to the same folder normally and open a Git Bash
git pull
your file will be there.


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FFMpeg Force Codec
I am dealing with a video that as a codec tag of none, but the actual codec is GHEC.  I am aware this is a proprietary codec from GeoVision.  The video will not play unless I use ffplay with the -vcodec hevc argument.  Since GHEC codec will play via hevc codec, is there any way I can force the codec to be hevc on this video so I can watch it in other media players like VLC?
Here are the streams from ffprobe:
    Stream #0:0: Video: none (GHEC / 0x43454847), none, 1920x1080, 451 kb/s, 30 fps, 30 tbr, 30 tbn, 30 tbc
    Stream #0:1: Subtitle: none, 3 kb/s
    Stream #0:2: Subtitle: none

Remux via ffmpeg with the decoder specified.

@Gyan anything I try keeps giving me this error: Output file #0 does not contain any stream.  I have tried ffmpeg -i in.avi -vcodec:hevc out.avi, ffmpeg -i in.avi -vcodec hevc out.avi, and ffmpeg -i -c:v codec hevc out.avi.  Are my commands correct?

Got it, looks like it -c:v hevc must come before the -i argument.

@Gyan If you want to answer my question I can accept the answer

If you know the compatible codec in ffmpeg, you can remux the file to generate a standard file, e.g.
ffmpeg -c:v hevc -i in.avi -c copy out.avi

Just an FYI - you can't just force a codec if the moov atom or headers are missing.
For that you need to repair the file by copying valid headers and atoms from another functional file created the same way.
The only utility that worked for me was https://codecpack.co/download/recover-mp4.html - which gives instructions when run without arguments, runs fine on wine, and worked, unlike untrunc and a bunch of other ffpmeg-based utilities.
(The file is archived here: http://web.archive.org/web/20220320003709/https://download1491.mediafire.com/u39upc91ggmg/yf8ct3b58ipbc3l/recover_mp4.zip)


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Is video output in YUY2 color space lossless if the input is sRGB?
I am considering purchasing one of these:
https://static.cloner-alliance.com/manual/ca-1080fl_user_manual_v1.1.pdf
It claims to be able to capture "uncompressed video", but in the list of output formats in the document above (page 67), it lists "MJPEG,YUY2". I know MJPEG is a compressed format, but I'm less certain about YUY2.
The source I'm considering is a Surface Pro 7 which outputs HDMI via a USB-C port. I am under the impression that the Surface is likely to output sRGB by default. My reading of the Wikipedia article on YUV leads me to believe that if the capture device receives an HDMI signal using the sRGB color space, and outputs a stream using the YUY2 color space, information must be lost (some discussion here seems to support this theory).
Is there any sense in which this device can claim to support "uncompressed" video or is that misleading?

It's a bit of a semantics game.  The YUY2 video mode is not "compressed," but it won't result in a bit-exact copy of RGB input.  The luminance is full resolution in that mode, but the chrominance is sampled at a lower resolution.  This is technically decimation rather than compression, but some information is indeed lost.
That said, if you are going to wind up posting your video online or something, it'll be even more decimated, and also subject to lossy compression.  So in most use cases, the loss of information from going into that YUY2 colorspace wouldn't be anything to really worry about one way or another.  You probably need to use some lossy compression to be able to reliably record it in real time unless you have very fast storage or are having the device output a low resolution.  If you really care about truly perfectly exact output for some sort of scientific image analysis process, you'd need more specialized hardware.


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Raising volume of one mic in an audio track to meet others' mics volumes
I have a long video where I and other people talk. Whereas the voices of others sound good, my mic captured mine with a very low volume. The problem is that the video is long and voices alternate, so I cannot go looking for every piece of audio where I talk and raising the volume one by one.

Is there a way to automatically raise my voice while keeping others' voices in a good level as they currently are?
I think I have to use some "compression" and "normalization" but I don't really know how they work, so if you provide specific steps it will be highly appreciated. I already played with normalization without much success. I attempted to increase the volume of the whole piece, so my voice reaches a good volume, and then "normalise" the volume to see if that will lower the voices of others to their initial state, but it didn't work (I probably did something wrong).

For it to sound good, you would certainly have to raise and lower the volume by hand using keyframes. If you want a quick and dirty solution, you can use a limiter or compressor. A limiter sets a ceiling of volume that cannot be surpassed. This way, you can turn up the volume significantly, which would make your voice touch this ceiling while others would be crashing through that ceiling. The limiter than lowers the volume of the parts that would crash through the ceiling, effectively putting loud and quiet parts closer together in volume.
However, you will also hear an extreme limiter / compression like this. Quiet sounds when nobody talks will be awkwardly loud, breaths sound like from an asmr video and you will most likely have a problem with background noise, which will be more audible aswell.
To avoid this problem in the first place, I would recommend you use microphones for each person that's speaking, so you can adjust the volume easily in post-production.

Do you have any advise about what parameters to use in the "Limiter" and "Multiband Compressor" in Resolve?

I have no idea about how to use the compressor... I did a small "patch" by raising the Volume and using the Limiter and there are some negative side effects but at least my voice can be heard. I will accept the answer, but if you are able to give advise on compressor parameters, I'll appreciate if you complete your answer with such details

@user1156544 Are you on a Mac or PC? (I ask because on the Mac, the AUDynamicsProcessor might more clearly show you what's happening than a multi-band compressor.)

I am on a PC...