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How is 29.97 timecode generated over a full day without frame errors?
A quick primer:American television was originally broadcast at 30 frames per second. In order to accommodate color information without losing backward-compatibility with B&W televisions, the framerate was slowed by a factor of 1000/1001, to approximately 29.97 FPS.
29.97 footage was still labeled as 30 FPS; however, the difference in framerate caused the timecode to be off by a minute-and-a-half per day, causing sync issues for broadcasters. To counteract this, "dropframe" timecode was developed. At 30 FPS, there are 18000 frames per ten minutes; at 29.97 exactly, there are 17982 frames per ten minutes. To account for the eighteen-frame difference, we "skip" two frames on every minute not divisible by 10. For example:
30 FPS
00:00:59:29 + 1 frame = 00:01:00:00
00:04:59:29 + 1 frame = 00:05:00:00
00:09:59:29 + 1 frame = 00:10:00:00

29.97 FPS, dropframe
00:00:59;29 + 1 frame = 00:01:00;02
00:04:59;29 + 1 frame = 00:05:00;02
00:09:59;29 + 1 frame = 00:10:00;00

The question:The math works out at exactly 29.97, but the framerate is slightly faster -- 30*(1000/1001) works out to 29.97002997002... The difference is negligible for any single piece of footage; the error here only works about to about two-and-a-half frames per twenty-four hours. But how does a master sync generator account for these extra frames? There's no labeling scheme for them, and midnight will not occur on a clean frame.

Interesting. Certainly, apps like FFmpeg don't account for the discrepancy. And the impression from search suggests neither do most other s/w or appliances.

As per the Broadcast Engineer's Reference Book, p. 203

This correction will match DF time to real time to within
  approximately 2.6 frames per day; to eliminate the residual error the
  timecode generator can be reset each midnight.

So, apparently nothing.
As far as the "extra" frames, Charles Poynton says,

If a timecode sequence is to be maintained longer than 24 hours,
  timecode should be jammed daily to reference clock time at an
  innocuous moment. No standard recommends when this should take place;
  however, the usual technique is to insert duplicate timecode numbers
  00:00:00;00 and 00:00:00;01. Editing equipment treats the duplicate
  codes as a timecode interruption.

This (very helpfully!) explains how the error is removed each day, but doesn't explain how the "extra" frames are handled.

I'm assuming they aren't handled. If they were, there would be no residual error to reset.

I don't mean "handled" as in "corrected"; I agree the error needs to be reset after every 24-hour periods. That said, 29.97 dropframe gives us 2,589,407 frame labels for a given 24-hour period, but the actual framerate requires labels for 2,589,409.6 frames -- unless the reset includes ignoring two frames each night, which seems to introduce a new sync issue.

@ErikD.  What issues do you see here, and where would they arise? Is there anything in your experience that indicates that this causes real-world problems, and for whom?

@JimMack I'm dealing with a CMS that stores timecode values as millisecond offsets from midnight. Assuming I'm using time-of-day timecode, I'm frame-inaccurate for any footage captured after about 2pm if I'm calculating at exactly 29.97 fps. If I use the correct 30 fps * (1000/1001), I have two and a half unlabelable frames for footage spanning midnight.

Can you customize the timecode function? Basically, you need to skip one of the two timecode frame drops at 9h16m6s and 18h32m13s.

The information so far: you're acquiring video content continuously at exactly 29.97 with no breaks ever, forever. Plus A) each video frame must have a unique label and B) these labels must always exactly match true time of day, within a small epsilon that averages to zero.
Given those conditions, there's no solution using only standard video sync and time code. You must compromise / customize something.
Some possibilities are:
1 - Resynchronize TC to TOD at every break in recording. I know we assumed no breaks, but no recording medium has infinite length. Scheduled breaks or resync points might be possible.
2 - Jam the TCG to TOD every "n" hours and live with the consequences.
3 - Store both the mSec-exact TOD and the TC (or the accumulated delta) in the CMS, and use them both on retrieval of a given frame. Couple this with a reset to 0 whenever possible.
4 - Use the user bits of the TC to encode the mSec-exact TOD, instead of storing it in the CMS database. However, the delta won't survive dubbing / editing.
5 - Similar to what @Mulvya suggests, customize the TC generation to not drop three normally-skipped frame labels each day. That would change the drift from -2.589 frames/day to +0.411 fr/day. This can be further corrected by skipping one of the not-drops every 2 days, making the average error term -0.02 fr/day, etc. You can continue this to any desired accuracy. This is only possible if your TC doesn't have to be used outside your own context. "Normal" systems for editing etc won't understand it.


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istockphoto for videos
I am thinking about make some story video and I would leverage some general footage -- timelapses, cars passing streets, etc. Is there some service which provides such assets? I think I saw something like "video building block" service or something like that. I don't need this service specifically, but just something where could I download/buy such video assets shoot by somebody else.

All the replies are cool. Which should I mark as the correct answer?! :)

I've used the following services:
Video Blocks - perhaps this is the one you were thinking of?
iStockPhoto
ShutterStock

Well, I think your best source to tell stories with would be public domain videoes.
Either videos placed directly into the public domain or those whose copyright has expired and are now in the public domain
see (a good resource):
http://www.pond5.com/free
For example, the charlie chaplin videos, all the silent movies, unfortunately all movies including the 70's should have been in the public domain by now if it wasn't for the walt disney copyright extension law. Oh well, we take things as they are. Lots of great resources to be found in the public domain.
other sites:
(Public domain films)
https://www.loc.gov/rr/mopic/pubdomain.html
https://archive.org/details/stock_footage

http://www.gettyimages.de/footage
https://www.shutterstock.com/video/
http://www.dissolve.com/
http://videohive.net/

to name a few, probably there are much much more.

source: Stack Exchange

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

sort: votes


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UHD video sample in 4:4:4
For my project I need to find or short video (1 min) of a UHD video in 4:4:4
I coudn't find any thanks to google.
I am now considering making one from 4 full HD stream in 4:4:4 but I don't know what tools I could use.
And by the way, although I read it's possible to make a full HD 4:4:4 stream from a 4K 4:2:0 I didn't find any sample available.
Any advice?

What's the use case for the sample?

Encoding evaluation

Will a synthetic video do, like an animated mandelbrot fractal?

So is the problem finding a Ffmpeg command-line to create uhd 444 video or finding a hi-res video sample? There is a lot of sample footage of all different cameras floating around on the Web I.e. Arri Alexa:https://www.arri.com/DE/camera/alexa/learn/alexa_sample_footage/

@Mulvya yes a synthetic video will be fine

@HansMeiser The problem is finding a uhd 444 video to test encoders performances. So, either creating a synthetic one, or just downloading it is fine.

You can use ffmpeg, a free command-line tool, to generate some synthetic videos in the required size and pixel format:
Mandelbrot fractal
ffmpeg -f lavfi -i "mandelbrot=s=3840x2160:r=24" -c:v libx264 -pix_fmt yuv444p -t 5 mb444.mov

This will generate a 5 second UHD video @ 24 fps. You can experiment with the various parameters detailed here, such as coloring methods or amount of zoom.
There's also filters to generate patterns as per Conway's Game of Life or a custom cellular automaton, although those will be very 'noisy' with default settings.
You can also use a test pattern as a source:
ffmpeg -f lavfi -i "testsrc=s=3840x2160:r=24" -c:v libx264 -pix_fmt yuv444p -t 5 test444.mov

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


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can we use "GoPro Hero 4" camera to shoot video tutorials or elearning courses or moocs?
Hello video stackexchange experts.
I need your help to know that is it good idea to use GoPro Hero 4 to shoot MOOCs or video tutorials?
I have listed out few of the sample videos here.
Clay Animation Set Design

Lecture 1 | Programming Methodology (Stanford)

Justice: What's The Right Thing To Do? Episode 01 "THE MORAL SIDE OF MURDER"

Learn Malayalam quick to read,write and speak in 7 days Part 1

BALL IN AIR

Oyster Mushroom cultivation Jeevika Bihar

Azure Backup for Windows Client

Mould making,casting & firing casting mould-Ceramics

Thanks

Closed - I see you have asked the same question in various ways. Please use one question rather than ask it for each type of camera.

sorry if you feel that this is duplicate. but it's not same question.

A GoPro may not be your best tool for this - it has a very wide angle lens, and is targeted at action and sports, mostly.
That said, you can still use them effectively if your scenes can cope with the distortion a wide angle camera brings. They are cheap and convenient. They cope well with various light levels, but the sound quality is possibly not as good as you'd like for interviews, for example.


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Convert variable input formats to black and white MP4
I am currently using an FFMPEG command like:
ffmpeg -i input.mov -vf scale=1920:1080 output.mp4
to convert varying input format file to a fixed resolution MP4 output file.  One final step I need is to make the output Black and White (the input files will be full color).
I have tried both
    -pix_fmt gray
and
    -vf format=gray,format=yuv422p
but both just result in a black output video.
After much trawling of google, it looks like the FFMPEG exe I downloaded (for windows) wasn't compiled with the "-enable-gray" option, but I don't know if this makes any difference and don't know how to obtain a windows FFMPEG with this option enabled (building FFMPEG myself looks like a lot of hard work).
Any advice welcome!  Thanks.
PS I should add that the conversion I'm currently doing and any grayscale conversion could be separate steps if required.

Yes, you do need a ffmpeg build with gray pixel format enabled. You should get your binary from the Windows link at ffmpeg. Download the latest 32-bit static build.
You can check if your build has gray enabled by running
ffmpeg -pix_fmts | findstr /r gray

It should list an entry for gray.
And use format=gray in your vf chain and -pix_fmt yuv420p together for broad compatibility.

The command below is for linux. grep will work as findstr!
ffmpeg -pix_fmts | grep -i gray

Running your command on my current FFMPEG results in
IO... gray                   1             8
IO... gray16be               1            16
IO... gray16le               1            16
Does this mean it has gray enabled?

Ok, just follow the last line of my answer. Should work with your current build.

Running the command
ffmpeg -i input.mov -vf format=gray -pix_fmt yuv420p output.mp4
results in a black screen.  I wonder if trying to do the conversion from .mov to mp4 at the same time is the problem? Now I think of it I'll try separate commands

Separating out the conversion from .mov -> .mp4 and the conversion to grayscale (using your commands) worked. Thanks :)

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


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Softwares for GPU accelerated rendering
I'm a YouTuber and I spend quite a lot of time solely to render my video (editing is sparse, mainly cutting boring scenes to keep the highlights of the episode) that I believe could be accelerated using GPU to render.
I've seen that most softwares use CPU to encode the video, however I was wondering if some of these softwares (such as Premiere which I haven't used yet) could accelerate the render process using both CPU and GPU.
I am currently using Sony Vegas, and during render while using CUDA, GPU load is around 20% which is a pitty I believe.

Adobe's CC suite will use the GPU, but the benefit you see from it depends on the power of your GPU compared to your CPU. This feature set is called the "Mercury Playback Engine" and contains, among other optimizations, CUDA support for certain realtime effects (scaling, crop, etc) as well as encoding/decoding.
However, most integrated or mobile GPU's aren't powerful enough to make it worth using CUDA acceleration. Fortunately Adobe is smart enough to transition back to CPU rendering when it detects wimpiness in the GPU department.
With a dedicated graphics card like a GTX970 you'll see a significant decrease in render time - perhaps as much as 50% (so I've heard, anecdotally, from other youtubers like yourself).

That's precisely the graphics card I bought. So you'd advise me to switch to Premiere ? Any information about such feature on Sony Vegas, which I'm used to ?

I haven't used Vegas since version 6 so I don't know what strides they've made in GPU acceleration since then.
I think you would be happy with the results you get in Premiere; the learning curve is a little tricky right out of the gate but it doesn't take long to figure out and is so very, very much more powerful.
Now that Creative Cloud is available, you can try it on a month-to-month basis and only be out $30 or so if you decide it doesn't live up to your expectations.

You can get Cuda and OpenCL acceleration for FFMPeg nowadays:

https://developer.nvidia.com/ffmpeg
https://trac.ffmpeg.org/wiki/HWAccelIntro


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Why does HDMI out on my Canon 5D Mark III work with my TV but not my Lilliput monitor or BlackMagic Design Shuttle 2?
Facts as I observe them:

I can use a mini-HDMI to HDMI cord to mirror my Canon 5D Mark III on my consumer Samsung television
I can use a consumer HDMI device such as an Apple TV to power my Lilliput monitor and capture over my BlackMagic Design Shuttle 2 -> UltraStudio Mini Recorder setup
I cannot use my Canon 5D Mark III to run HDMI over the  Shuttle 2 -> Mini Recorder

The video is set to 1920x1080 with 30fps. I know the BlackMagic devices like 720p59.94 and  and 1080p59.94.  I have up-to-date 1.3.3 Canon firmware and have default settings except for HDMI output + LCD setting which is set to Mirroring. I am set to P mode.
I've established a Computer<->Mini Recorder setup in multiple applications using the working input so I believe the issue to be between the camera and the devices receiving its HDMI out. The behavior of the camera seems to change when I plug its output into one of the non-working sources, apparently leaving movie mode. When connected to the monitor and I turn it off, the display returns from black.
My guess here is that the TV is capable of some wildly varying HDMI standards while my camera and/or BlackMagic gear is not. It may not be capable of handling whatever 1920x1080 30fps IPB output ends up being.  This seems relevant:

-Has nothing to do with HDCP compliance, not required, so that is good.
-If you have a display that does not work at 1080 in the live view mode with the Canon 5D Mark II it is probably attributable to one of
  two things: Native preferred timing not set to 1920x1080i in monitor's
  EDID or that the display type is listed as RGB color and default color
  space is listed as sRGB in the monitor's EDID.

Can anyone tell me what may be causing this apparently flippant behavior and for bonus karma suggest a workaround?

Which Lilliput monitor do you have and what exactly is the output format of the 5d Mkiii?
Not all Lilliput screens can display progressive resolutions. Sometimes cameras provide "fake" interlaced on the monitor out (PsF) even if recording progressive to avoid that problem. It is a common problem with the BM Pocket Cinema Camera and (some) Lilliput screens since the BMPCC only outputs 24p/25p/30p.
Here is a list of hdmi modes the different Lilliput models support: http://lilliputdirect.com/index.php?route=supported-hdmi-modes
There is no quick workaround to that problem since the hyperdeck shuttle does simple hdmi pass-through and no image conversion.

Some DSLRs output HDMI video that does not meet full HDMI specifications. It is not unusual to find combinations of source and destination gear that is incompatible.  The HDMI can be viewed on permissive screens (consumer TV receivers, etc.) but not on more professional gear that strictly adheres to the HDMI standard protocols.

As far as I know, this has nothing to do with the HDMI specs. Progressive resolutions are definitely part of the hdmi specs. I think the reason why a lot of cheap monitors cannot display certain resolutions is because they use a certain, fairly cheap hdmi display driver by realtek which simply cannot handle progressive resolutions.


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Thunderbolt 3 & eGPU viable for Video Processing?
I am pondering about getting a (new) notebook at some point. Apparently TB3 (officially) supports external GPU's now. The problem is that the speed of TB3 is still much lower than Pci-x... So I was wondering - and maybe someone knowledgeable can give some insight - if a notebook with TB3 and an eGPU will be a viable solution for video processing with davinci resolve and other gpu accelerated software, or how important is the "low" IO speed of TB3 vs PCI in that context?

I've looked into this recently myself, given that the MBP line is not exactly a workhorse when it comes to GPU processing.
eGPUs are actually being done now over TB2, with great success. I have a friend who purchased a similar unit to the Akitio Thunder2 (the Bizon-Tech version), put a decent GPU in it (I think it was the GTX960 or similar), and experienced almost 50% faster render time in Premiere (the latest versions of CC support GPU acceleration for encode/decode with some codecs).
The math gets a little funky, but actually this Tested article comparing PCI Express to Thunderbolt indicates that the Thunderbolt2 spec, in practice, provides almost the equivalent of a PCIe3.0 interface. The bandwidth speed lost will be minimal. Further, the article indicates that performance of the graphics card that is lost by a slower transfer speed is, for all practical intents and purposes, negligible (as little as 5% in most cases).
I'm certain that the performance gained by an eGPU box, even over TB2 on current-gen hardware, would vastly outstrip the current performance you're getting on a CPU-accellerated-only laptop.
And, the best part is, you're out only around $1500 for a box and a good graphics card.
For the record:
I don't know what notebook you're using, but I'll assume a relatively recent MBP. I'm working here from a 2014 15" Retina which happens to have dual GPUs (integrated Intel Iris and discrete GeForce GT 750M), and based strictly on CUDA cores, you'll have to pick up something in the K1200+ range if you want to see a significant improvement (the GT750M has 384 cores). However, it's relatively weak at only 2GB GDDR5 (roughly comparable to a K620 in terms of cuda cores and memory).
Improving both specs is important, particularly for 4K or RAW video. I would recommend something like a K2200 or K5000, or if you've had a good year, any of the Maxwell-class cards would be a beautiful, beautiful thing.

TechInferno - 2015 MBP + GTX970 + Akitio Thunder2 via TB2
LinusTechTips - 2012 MBP + GTX760 + Akitio Thunder2 via TB1
Bizon-Tech - Akitio-based custom enclosure for high-wattage GPUs
A useful comparison of top-end Kepler vs Maxwell NVIDIA architecture
Anecdotally, in 2014 I saw a live demo in NVIDIA's booth at NAB of what the K6000 card is capable of - at the time, mindblowing performance. They put dual K6000's in a Z820 workstation and did realtime 4k debayering of RED Raw, with scale and blur effects, in Premiere. So yeah, duh - it's a powerful card, right? Point is, you don't have to look at the latest Maxwell cards to get performance improvements in an eGPU setup - even a single quality card will provide much more efficient and expedient results than CPU-only.

I looked into that option a long time ago and it involved some crude driver hacking at that time... TB2 didn't officially support eGPU while TB3 does... That's why I would hope the whole Ecosystem would get more user friendly and probably also cheaper.

Yes and yes. You're right, it's not very userfriendly.

That being said, I'm told that on Windows it's almost plug-and-play once you get Thunderbolt to play nice. Nvidia does all the heavy lifting of making the integrated and offboard GPUs play nicely.
Using windows in bootcamp mode is no joke, but a 50% performance boost - especially over a comparatively light card like the GTX970 - almost makes one want to implement the system just for rendering, although admittedly running Resolve without GPU acceleration is not pleasant.

As for the notebook, I have two ancient mbp, 2008 and 2009... That's why have to do this research... As you mentioned the top MBP does not only have a "not to great" gpu, also I find the price of 2500€ ridiculous for what you would get in Windows notebooks nowadays. Actually I considered changing to Windows because of that which would be a huge pita, or trying to run some sort of hackintosh notebook.

The limitations of Macbook GPUs is a pretty widely known deal, and so I can easily imagine that once TB3 becomes a real thing, it won't take long for eGPU TB3 enclosures to appear. That being said, staying on the Apple platform is an expensive brand commitment, haha! Not to mention that Apple is clearly transitioning to AMD cards, which don't support CUDA, which are therefore useless for many GPU-accelerated applications. Resolve, in particular, does support OpenCL, but perhaps not as thoroughly. Adobe's products are not OpenCL compatible at all, at this time.

I think this is not valid for recent resolve versions which do seem to support OpenCL. I am also not keen on either doing as switch from osx to Windows, neither from CUDA to OpenCL but apple seems not to bother about their pro users at all anymore since iPhone an ipad became the 90% source of their revenue.

For completeness, and in the interest of non-Mac users who may see this question in the future, I should share links to a couple other eGPU products that are commercially available today (April 2016, this will change and probably as soon as the end of the month after the NAB show in Vegas):
Alienware Graphics Amplifier - this is a fully proprietary box (with a proprietary AW connector) that performs essentially the same functionality as the Akitio or Bizon box, albeit way cooler and awesomer. And not expensive by comparison - only $200, without a graphics card.
Razer Blade Stealth + Core - this is a TB3/USB-C protocol in a sleek little enclosure for $500 empty. Compatible with laptops sporting the USB-C protocol, this is a great option going forward for many laptop users. Polygon did a great writeup about it.
All in all, you're still out at least $1500 for a solid external GPU solution, but there are some nice options out there.


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Cropping a Video based on a motion track
I have some raw footage from a lacrosse game that I filmed and the coach told me to make a video for a collage about a player.  Is there a way to crop a video relative to a motion track.
I would want to track the player and crop the video so the player stays in the center of the frame rather than giving the coach general footage with the player in it. I understand that I will be giving up a lot of quality cropping the video to a small size but just having the ability of doing such a thing would be nice.
Programs to use:
- Blender
- After Effects CC
- Premiere Pro CC
- Any of the programs in Adobe CC

Here's one way to do it. I'll assume you have basic motion tracking knowledge already for the sake of brevity.
AfterEffects

Turn on 3D space for your footage layer.
Track the player in your footage. I'm going to guess that you'll have to do a lot of this by hand, but there's not really a faster way to track a player like this.
Apply the track to a Null, including both X + Y values of course. Turn on 3D space for the null as well.
Create a Camera. Default values are fine. They will match your footage, so you initially won't see any change.
Select the Null and press P to open the position parameter.
Here's the tricky part. Alt+Click on the Position stopwatch for your Camera. This will turn the position numbers red, open up an Expression text box, and reveal some new buttons. Click and drag the Pickwhip onto the Null's position parameter.

Your comp should go black. Good, it's working!
Open up the Position twirly for your footage layer (in my comp it's A037C006_160309CZ.MXF). The third value is the Z-depth. Adjust this to taste - the larger the number, the larger the resulting "crop" of your footage. Here I've set it to 1700 for a pretty extreme crop (and this is also 4K footage) - a more reasonable look, in my case, might be more like 2500. For you it will vary depending on the footage.
As you scrub through the timeline you should be perfectly locked onto the player. Unfortunately, depending on how close they get to the edge of the shot, you may see black appearing at the edge. This means you've "cropped" in far enough that you've hit the edge of the frame. You can reduce the crop (move the footage layer closer to the camera, a smaller number) as necessary to fix this.

You may find that your track is a bit choppy. You can smooth it out a bit non-destructively using some of the techniques detailed here.

Worked for me! But i had to specify to create a single node camera.


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Playing in time line stops when the bar touches the mark out point
Basically my questions is: what is this orange bar attached to the playing cursor and how can I remove it to make the cursor stop at the marker when I'm playing selection. Many thanks!

In your screenshot it is difficult to see if you are talking about the render status as described here, maybe you can check that:
http://blogs.adobe.com/premierepro/2011/02/red-yellow-and-green-render-bars.html

The orange bar is the frame indicator. In the screenshot, the playhead is displaying the last frame of your in/out range.
If the playhead stopped one frame further, as you suggest, it would be showing the next frame AFTER your in/out range (and could be confusing, although obviously this method is too!).

Still, just pressing regular "play" shouldn't stop at the out point, or did i misunderstand something? In Avid Mediacomposer there was a function called "play to out" but i have never seen such a thing in premiere.

It is frame indicator.
Your timeline is really zoomed in. So you see every frame. Your out point is standing in one place, and that mean, that you want video-editor to play till that point in video. To show you that point in the video video-editor shall show you previous frame. If it will show you next frame, that will be after your out point, since next frame will start in that point and last for about 1/30 of a second (depends on your framerate)

The orange bar is an out point, meaning "if you are playing or rendering video, anything that sequentially moves through frames, stop now."
You can clear the out point by clicking RMB (right mouse button) in the timeline area just above the horizontal red line and choosing the option "Clear Out Point" (or "Clear out").

As mentioned in my other comment, I am not aware that play stops on out-points. Is this a new behaviour in premiere?

Just tried it: playback does not stop on out points unless there is something equivalent as avid mediacomposers "play to out" function.


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Why does 8K have 16 times the pixels compared to 1080p?
Considering 2K = 1440p, has twice the pixels compared to 1080p, 4k has four times as many, why does 8k not follow this trend?

First off, 2K is not 1440p, it is 2048 x 1080p.  4K is 4096 x 2160p.  (Note that UHD = 3840 x 2160p...4K and UHD are like US and Canadian dollars--they are both dollars, but they have different values.)
It's simple math: when you have a straight line and you make it twice as long, the new length is 2x the original length.  When you have a rectangular area and you double both the length and the width in order to keep the same aspect ratio, the new area = (2L) * (2W) = 4 * (L*W)
When you double something twice, you do it again:
2*(2L) * 2*(2W) = 4 * 4 * (L*W) = 16 * (L * W)

Ah, I get that now. 2k 4k are based on horizontal length only, rather than number if pixels. This had me confused, as I had assumed 8k would be 1080p *sqrt(8). Thanks

8K = 8000 x 8000, if 1:1. But you normaly have 16:9 for videos which is 7680 * 4320, since 7680 ≈ 8000, the width is rounded to 8K, if 9:16 aspect ratio, then the height is rounded to 8K.

7680 * 4320 = 33177600 which is 33MegaPixels, since 33177600 ≈ 33 Million Pixels.

33 / 4 ≈ 8. 8MP is 4K when 16:9 aspect ratio. Since 3840×2160 = 8294400 ≈ 8 Million pixels. The reason it's Mega is because Mega is a greek word and means 10^6 which is Million.

So 1080p is easy since 1920 x 1080 ≈ 2MP. Since 2 073 600 is ≈ 2 Million.

What is then 2MP x 16? It's 32MP. 8K on an 16:9 Aspect ratio is ≈ 33MP, but on an 2:1 Aspect ratio it would be 32MP, since 8K x 4K would be 32 Million.

Let's do a final calculation.
8K x 4K (8K) = 32MP.
4K x 2K (4K) = 8MP.
2K x 1K (2K, at 16:9 it's called 1080p) = 2MP.
2 x 4 = 8
8 x 4 = 32.
4 x 4 = 16.
So 16 times since you multiply the width with 4 and the height with 4.
(x4) * (y4).
at 2K with aspect ratio of 16:9:
x would be width, so x is 1920,
y would be height, so y is 1080.
(1920 * 4) * (1080 * 4)= 7680 * 4320 = 33177600 ≈ 33MP
So as you can see 7680 * 4320 is called 8K.

https://en.wikipedia.org/wiki/8K_resolution


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PC instead of external recorder
I have a camera which outputs uncompressed HDMI. I understand that I can buy an external recorder (e.g., Atomos) to record the video, but is it possible to use an ordinary laptop (or desktop) computer instead?

In the end, I found out that you can buy a dongle (in my case an INOGENI 4K USB) that will connect the camera to the computer via USB (amazingly, USB 3 is fast enough) or, in the case of BlackMagic Mini Recorder (which does 1080p only), thunderbolt.
The next challenge is, of course, to encode 4K fast enough on a laptop.

Blackmagic Design's Decklink cards are a starting place for desktop computers: https://www.blackmagicdesign.com/products/decklink
For laptops there's both Intensity: https://www.blackmagicdesign.com/products/intensity
And UltraStudio: https://www.blackmagicdesign.com/products/ultrastudiousb3
Other companies also make such products (and even Blackmagic Design offer yet more options), but the above provides a range of answers to your question.


text:
Second a day video "counter"
I'm trying to edit my 1 Second a day type of video and I'm unsure how to put a date below which increases every second?
The text would look something like this: "April 6 2016",
then after a second it would change to: "April 7 2016".
Any idea how I could do it?

In Sony Vegas you can use Text Wizard from Vegasaur Toolkit. It can easily create various counters. Vegasaur has free 30-day trial, so just install it and go to menu View > Extensions > Vegasaur > Timeline > Text Generation Wizard.
Please note that the appearance of the text (font, color, size, etc.) is determined by the selected preset.


text:
Surroundings moves faster than the subject?
How to edit/shoot a scene where the person(subject) in center moves normally while the surroundings(background) moves faster?
Example:
I'm walking in the street but the cars and other people that passes me are faster than me.
P.S. I can't find it in youtube or other blogs because I don't know the term of this kind of technique yet.
BTW, I am a newbie.

If you are talking about I.e. the effect used in this video by orbital: https://youtu.be/ymu_ogcXigg...  this is done by letting run the camera in time lapse mode and moving very slowly, making the surrounding appear very fast.

Actually I already thought about that but I saw a lot of scene where the subject moves normally (not moving slowly then time lapse the surrounding)..
I will look like not moving normally when I will do that technique. But if that's the only way, then I'll try my best to move slowly but looks like natural in output.
Thanks.


text:
How can I rotate a video by a few degrees?
I've taken a fairly tilted video and want to rotate it to be level, how can I do this? I'm open to any third-party apps but purely apple solutions are better.
Thanks for you help!

Using FCPX, a Transform effect will do the trick.
Using FCP 7, you can access rotation along with scale and position in the Motion tab of the Viewer.


text:
Canon Vixia HF R600 - MP4 vs AVCHD
I just bought a Canon Vixia HF R600. It's giving me the option to save files as AVCHD or MP4. I will be importing them to my PC and editing them in Adobe Premiere CC.  I'd heard that AVCHD has a better picture quality, but I also heard that AVCHD requires multiple files (???). My questions are:

Can Adobe Premiere CC work equally well with both file types?
Which file type will give better image quality?
Does a single AVCHD clip really comprise multiple files that I'll have to import?

Thanks!

Generally, MP4 is better for compatibility, whereas AVCHD provides the better quality. MP4 (which by the way can mean a million different things, in this case it probably refers to MPEG-4 Part 14) files will be compatible with most devices and media players as is, and will be smaller in size compared to AVCHD. This is the option I'd recommend if you wanted to film your vacation and show the recordings as is, without further editing.
If you want the best quality, go with AVCHD. Files will be bigger in size and won't play back on most devices, but you can import them into Premiere Pro and export your edited video to every format you want anyway. Chosing the AVCHD will also open up other recording options on your camera. According to the manual, the highest bitrate avaiable for MP4 is 35Mbps. For AVCHD, the highest possible bitrate should be even higher, though I couldn't find an exact value.

Can Adobe Premiere CC work equally well with both file types?

Yes. MP4 will record, well .mp4 files. AVHCD will probably come as .mts or .m2t/.m2ts files, both of which Premiere Pro can handle.

Which file type will give better image quality?

AVCHD with the highest recording quality settings. Keep in mind that this will fill up your SD card pretty quickly, according to the manual at about 4 GB per 20 minutes of recording. If this is a problem for you, MP4 might be the better solution, as it offers the better quality/filesize-ratio.

Does a single AVCHD clip really comprise multiple files that I'll have to import?

Not really sure about that. Normally, it should produce one container file every time you press record. Many cameras will split the file at 4 GB or stop the recording when a continuous recording reaches that size. Since you already bought the camera, just try out both options and see what files you get. But Premiere pro should be able to handle whatever you throw at it.

I have Lumix G6 with same options (MP4 and AVCHD).
Some things about AVCHD:

It brake video into multiple files, but since you gonna edit them in Premiere, you can handle this.
Sometimes Adobe Premiere have problems with audio at AVCHD. If Premiere don't see audio in AVCHD files, that mean you have problems with your license. You shall reactivate it. And no crack will help with that, only payed license will work. Even demo version of Adobe Premiere will not.
In my camera you can record about 4 time more in AVCHD, so I always choose it.


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Techniques for compressing a slideshow presentation video?
I often do QuickTime screen recordings of slideshow presentations (e.g. Keynote).
These videos are 1080p 60fps and mostly text. They can go for minutes at a time with the same exact frame on-screen (static slide) yet have 60fps transitions between slides.
What are some compression tools or techniques that work best for this kind of video? I’m looking for something that keeps the text sharp while maintaining the 60fps animation transitions, without the file size being insane.
I’m not looking for answers like “use the Export for 1080p menu in QuickTime”. The best answer will have a solution that’s customized for the specific needs of a slideshow presentation video, perhaps using variable frame rate compression techniques.

-tune stillimage is, strictly speaking, meant for one static image for the span of the video, and will impact the slide turnover parts if those aren't simple cuts. And in my experience, I've gotten smaller files without it.

x264 is the best-in-class encoder for generating H.264 video streams and you can use it via ffmpeg, a command-line tool, to encode to a small-sized file. Get a binary from here - opt for the latest nightly/snapshot release - and run
ffmpeg -i input.mov -c:v libx264 -crf 23 output.mov

The output will be the same constant frame rate as the input but x264 is very good at minimizing space consumed by frames which are the same as preceding ones. Lower CRF values produce better quality files at the cost of larger file sizes. 18 to 28 is a decent range to stick within.

This worked beautifully. I had a 17 minute 1080p screen capture of a Keynote presentation. Using this command, I was able to compress it from 278 MB to 38 MB, which is exactly what I wanted.

I would update this answer to include x265. My experience with a 61 minute recording of a slideshow presentation was the following. Original: AVC/AAC = 1.13 GB , x264/AAC (CRF=28) = 154 MB, x265/AAC (CRF=28) = 127 MB

I would consider that a marginal improvement considering heavier resource use for s/w HEVC decoding.

@Gyan Not to mention the significant increase in encoding time as well (when bulk converting videos)!

@Gyan Shaving 17.5% off of the file size of x264 is not a "marginal" improvement, and while often notoriously slow with motion content, x265 encoding time is extremely fast with videos composed almost entirely of static frames like a slideshow. I just encoded a 1280x720 5-minute greentext reading video with x265 Faster RF27.5 on a Ryzen 7 3700X in 43 seconds, for example; non-slideshow videos take 2-3 minutes on the same machine even if downscaling to 960x540.

From what I understand, x265 hardware decoders are now included as parts of the modern CPUs, so the resource usage is less of a reason not to use x265 now.


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After Effects Mask is cropping down resolution
I have two videos, from one I create a mask.
In preview I have output fine.
Preview:

In RAM preview and render queue, output is weird:

I am a beginner ,using After Effects CS6 trial.
I have followed several masks tutorials, not a single tutorial has addressed this issue. I am using no effects at all, there are only 2 videos.

Set the RAM preview resolution to full.


text:
Reveal entire layer in after effects with mask partial overlap
I'm looking for a way to reveal my entire layer when a portion of my mask covers the layer. I have a composition with multiple individual layers, that I want to reveal with a set matte. However lets say when 30 percent of the layer is covered I would like the entire layer to appear. When it's less than 30 percent the layer does not need to appear.
Another option may be a correlation between opacity and area covered. Like 20 percent covered 20 percent opacity, 60 percent covered 60 percent opacity, etc

As far as i see, the way to go for this would be through expressions. Unfortunately AE "Expressions" don't seem to have a parameter to query individual mask points and thereby gather data to calculate the size they cover. I think it could be helpful if you described what you are trying to achieve, to enable others to think if there is another way than you are envisioning it.

For example i didnt quite understand how (and why) the mask is changing its size, what the shape is (square, round, elliptic, complex) etc.pp.

Sure! I am making a project that attempts to combine an art and music work. There are columns of pictures in the artwork. The masks key points are extracted from the audio of the music so that it becomes bigger at louder points. The mask I created is a rectangle placed in the center of the artwork. Since the artwork is a grouping of separate compositions, I would prefer for the pieces to appear together.

To make an analogy, it would be like revealing lego blocks with a mask. You want them to be revealed with a mask, but the lego block is seen to appear as a single unit instead of partial pieces

Ok, so just an idea: audio levels are relatively equivalent to mask size, right? So if you cannot query mask size, you could use the audio level values to additionally set opacity by using an expression, which would be fairly easy...

http://www.motionscript.com/design-guide/basic-audio.html
which is probably what you are doing already, if mask size responds to audio level... just additionally add it to opacity as well! (unless i misunderstood what you want to do ;)

Right! I think I know what you mean, but I think I'm trying to do something a little different. I'll put more detail in lego terms to see. There is a wall of legos in the composition. I am revealing these separate layers (one for each block) with a mask (set matte) rectangle in the center whose scale is dictated by an audio file. So the louder the audio the more blocks are revealed. However what I want to change is that I want either a lego to appear or not. I do not want the mask to reveal parts of the block like it cuts into right now. Is that different from what it sounded like before?

I think your description of what you want would be much simpler with a few pictures/sketches/screenshots - it's a bit tricky to understand as text!

So, if we will continue analogy with Lego blocks:

First you need add On & Off effect for your blocks. You can find here how.
Then you shall add Collision detection. You can find about it here.
Now you need to trigger On & Off effect when your object (mask?) collide with block.

I never tried it myself, but now really want to test it!

Thank you so much! This is great thank you!! to clarify the way you are suggesting would mean I am copying the code from the collision detection into the on/off effect? It seems the code may be used in itself to have an on/off effect, by saying its on (100% opacity) when it detects collision and off (30% opacity) otherwise. If this is possible, where in the layer would you put the collision code if you did not use the on off effect?

Once again, I don't have experience in doing it myself. You shall try it couple different ways on 2-3 objects, and when you will find correct way, just do it for whole project.


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Trimming audio source in Adobe Premiere
I want to actually trim out part of my audio in source window. I don't want a sub-clip which seems to be linked to actual full source audio, but rather to modify the source buy cutting out unnecessary part of it. Cannot find the tool to do that.

Adobe Premiere is Non-linear editing application. Any changes made in it don't have any influence on footage on your hard drive. Not audio, not video.
It is feature, which prevent damaging footage files.
It is based on trimming, not cutting. However, if you really want it, you can trim your audio, export it from Premiere, and then import back. But I can't find any reason, why you can need that.


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Easiest workflow to get better audio when using a DSLR
I'm looking for some information (note: not a product recommendation) for getting better audio when using a DSLR. Generally, the built-in microphones on DSLRs leave a lot to be desired, so professionals will have a separate sound guy who holds a boom mic or sets up subjects with lavalier microphones or something like that. Let's assume that neither of those are options - I'm just a guy with a camera that likes shooting videos, but I don't like the way the audio sounds.
I'm trying to enumerate my possibilities in terms of getting better audio. I've only come across two so far, with some of the pros and cons I've determined, purely from research. Please let me know what you think, if I've misunderstood or overlooked something.

Improved mic on the camera, recording into camera

Shotgun mic can be placed on top of the camera shoe, with a 3.5mm jack recording directly in to the video file on the camera's memory card
Pros: Super easy, no constant set up, possibly adjusting levels on the mic if that's an option it offers. Audio is already synced up.
Cons: Only one audio source (it replaces the camera's source), mic requires its own batteries (won't pull from the camera's battery)

Improved mic on camera, recording to a separate source

Same idea, put a microphone on the camera's shoe, but either record to an SD card inside the microphone, or buy a separate audio recorder
Pros: Multiple audio sources, more control over audio with the second recorder
Cons: Lots of gear to manage, lots of batteries to manage, have to hit record in two places as opposed to one and then sync up the audio in post

I'm leaning towards the first option purely because it's easier. What do you think? Is there another method to getting better audio?

Depending on the level of quality you want to operate at, these two recording options you mentioned are pretty much it: record externally or internally.
The reason to record externally are more than you mention, I.e if shooting an interview, you can leave the sound running but turn off the camera for the moments that are not so interesting.
Also, the "cons" are not so big: syncing can be done by audio fingerprinting automatically in premiere or using an external software like pluraleyes. You can even record smpte timecode with a device like tentaclesync and synchronize audio and video automatically by timecode.
Additionally you will often encounter situations where it is desirable that the microphone is not tethered to the camera, I.e. When shooting a distant wide shot but wanting the mic to be closer.
Also, dlsr cameras internal recording quality is not great in comparison to a proper sound recorder.
While the other cons you mentioned of "dual sound" recordings are valid, I think it is something you will get used to pretty quickly. So, waging your options I think you have to decide between slightly more work but better sound and less work but worse sound.

Thank you very much for your answer - it's made me reconsider the "dual sound" idea. I looked into some syncing software, and even the built-in abilities of Premiere seem like they'd probably be good, plus Pluraleyes like you mentioned can provide additional functionality for some more money. If you don't mind me asking a followup question (not about the products themselves, but about the type of product) - would you suggest something like this, with on-microphone recording http://www.bhphotovideo.com/c/product/966010-REG/shure_vp83f_condenser_shotgun_mic.html, or (sorry, character limit...)

Or something like this - http://www.bhphotovideo.com/c/product/929347-REG/tascam_dr_60d_4_ch_track_linear_pcm.html/www.bhphotovideo.com/c/product/929347-REG/tascam_dr_60d_4_ch_track_linear_pcm.html, with much more control? I imagine the audio geek would prefer the second one, but I'm leaning towards the first because it's more set-it-and-forget-it, knowing full-well that more control will lead to better audio. I'd prefer at this point to focus on the video, but just improve the audio slightly, rather than give myself a dozen new dials to adjust with every new situation.

I personally use a Fostex fr2-le in conjunction with a Sennheiser ME66/K6 microphone. The only advice I can give you in terms of choosing a recorder and a mic: try them hands on. There are a couple of Shotgun mic comparisons on the Internet which will give you an idea of how a entry level mic sounds in comparison to a medium or high end level mic. In terms of sound recorders, the most important part is the usability (how well can you adjust sound levels while shooting, see the meters etc.) and, how good are the preamp.

The difference between good and bad preamps will show when you record some very soft sounds and crank up the preamp / volume to get a decent level. With shitty preamps you will get a lot of noise, with good ones not. Another important piece of gear to get better sound during recording is to actually have a clear idea WHAT exactly you are recording. Mostly people use closed headphones for that purpose (to block out ambient noise and prevent feedback when using recording volume cranked up..

The Sennheiser hd25 headphones are a lot used by sound recordists, while not cheap, they sound much better than your average "beats" by Dr.dre crap, which are ridiculously expensive

The zoom series of recorders have the advantage that the built in mics can be used to record decent quality ambient recordings / room tones as well. Also useful when recording stage events like concerts, theatre plays, etc is to have 4 tracks, so you can record the ambient (noises of dancers actors on stage, audience etc) but additionally record the output of a sound mixing desk on the other tracks.

Wonderful advice - looks like I have a lot more research to do, but I really appreciate it! Thank you!

Imagine using a point-and-shoot camera where you point the camera at something but instead of actually looking through the viewfinder, you only pay attention to whether or not you see an exposure warning light.  You don't validate focus.  You don't validate composition.  You only validate that the sensor is receiving signal not blocked by the lens cap.  That is kinda how people treat audio, whether using internal microphones or shotguns strapped on to their cameras.  When they listen, rather than just looking at the meters, they are still mostly validating that signal is passing through the microphone.
What you can learn by listening to the microphone as carefully as you might look at framing, composition, balance, focus, perspective, etc., is that many audio environments are a mess.  Many audio environments mess up sounds that can only be recognized/understood because we have a really good stereo imaging system (our ears) and a very powerful noise rejection / signal enhancement system (our brain).  Randomly locating a microphone in such an environment can sufficiently compromise the signal that our ears and our brain cannot properly (or will not happily) decode it.  The solution to that problem is to place the microphone where it is not overwhelmed with flutter echo, modal resonances and cancellations, etc.  Usually, that means placing the microphone 3x closer to the source than to any source of confusion, which means keeping it within 6"-36" of the source source (depending on microphone type, source type, room behavior, etc).  The reason that pro sound guys boom their mics is because there is absolutely no substitute for putting the microphone in the right place.  The reason they use $1000 microphones is because if you are going to go to the trouble of getting good sound, you might as well get excellent sound.
There is essentially no microphone you can buy and attach to your camera that will give you good sound in a variety of circumstances.  There are many mics you can buy and attach to your camera that will give you good sound in one particular circumstance: your talent is approximately 2' in front of the camera, and there's no terrible acoustically reflective surface too close to either the talent or the camera.
DSLRs often add insult to injury by also having poor quality preamps that compromise both good and poor microphone outputs.  But the most important factor in audio quality is location, then an appropriate microphone type (omni, cardiod, super-cardiod, figure-8, etc) for the location, then the quality of implementation of that microphone, then the quality of implementation of the preamp and finally the digital recording format.

You're absolutely right with regards to how important sound is to video, in addition to why the professionals hire actual sound guys to do nothing but sound. Unfortunately, I'm not in the film industry, I just want better audio from my DSLR - so while it certainly won't be professional sound, it could definitely be better than what I have on my DSLR, I'm sure

Michael, that's a pretty good description of how audio is usually treated! There is also a significant amount of people on the Web that have a 10.000$ camera setup, but then think a 30€ lavalier from eBay will do wonders in terms of sound.


text:
Fix bad files and streams with ffmpeg so VLC and other players would not crash
It happened me many times that I could end up in corrupted video files:

video downloaded from official sources but with torrent and for some reason not all the pieces are there in .mkv, .ts or .mp4
records in .ts format where at a certain point the data is missing
copied videos from an old hard drive with damaged sectors

When I play this videos with VLC or other players they plays till a certain point and then instantly exits. Sometimes I can try to skip the bad part but I could meet another bad sector and have an insta-quit again.
Question is:
Can I fix this problems (I suppose stream and keyframes related) with ffmpeg and maybe in a -c copy fashion so I haven't to recompress everything?
What I want to achieve is a full lenght video where the missing parts are skipped, I prefer a glitch rather than having my videos crash.

See also: https://superuser.com/questions/538829/repairing-corrupt-mp4

If parts of the file reside on physically bad sectors, or for whatever reason, the OS cannot serve the whole file to FFmpeg, then naturally FFmpeg can't do anything about that. You should get a utility which can ignore those portions and write the salvageable parts to a new file, like ddrescue.
Now, if the file protocol is not the cause of errors, you can try
ffmpeg -err_detect ignore_err -i video.mkv -c copy video_fixed.mkv

This works, but fails without -c copy.  Surprising that it doesn't work during recode.

Even with that, I'm still getting Invalid data found when processing input -- and ffmpeg gives up.

Nice solution... if the moov atom (on a MP4 file) is still present somewhere. What if it's not even there?

It works at my end with surprising goodness :)

Not worked:
moov atom not found video.mp4: Invalid data found when processing input

This unfortunately consistently destroys any video file for me that I originally created with either OBS or ffmpeg

@aggregate1166877 it creates a new file, so it can't destroy anything...

@user924 I don't mean that it deletes the old file, I mean that the new file is completely broken. English is not my first language, maybe I used phrasing not valid in English.

In the search of a better answer a possible way could be:
ffmpeg -i video.mkv -c copy video_fixed.mkv

However I'm pretty sure there are some extra options that can make the result even better..

Works for me every time I have some kind of issue with the meta data, timestamps, or container info. And it's very fast, usually faster than 400x playspeed.

This command saved my butt, to be frankly.

What does it even do it looks like a copy | paste to me?

@RicardoBohner do you mean the answer or the command? in case of the answer it was originally posted by me 1 day before the selected one, regarding the command instead it does a copy but also reading the data and checking for integrity fixes the stream.

I meant the command, and I didn't know that ffmpeg did integrity fixes when using the copy codec...thanks for clarification.

I've tested lot of solutions and software. I love cli commands, so using ffmpeg you can fix your video file with no hassle. Try the next command if you came here searching some useful fix:
ffmpeg -vcodec mpeg4 -b:v 7561k -qscale:v 2 -acodec aac -ac 2 -async 1 -strict experimental ./video_fixed.mp4 -threads 0 -i damage_file.mp4

Good luck !

This will probably work, but the file will be HUGE! Better so just use H264 again, like: ffmpeg.exe -i "input.mp4" -c:v libx264 -crf 22 -preset slow output.mp4

this is the only thing that worked. Can you please explain the flags? why does it work and how can it be optimized

I had a video which I composed of 3 separate videos with -f concat and -safe 0, however, while the result played in VLC, in Davinci I could only see the video up to the first merge point (audio was still fine, though). After that Davinci showed a red media offline message. I first tried simply ffmpeg -c copy to fix the video but that did not work, however this re-encoding worked.

I had an mp4 that didn't have a thumbnail and claimed wrong resolution in properties. Doing ffmpeg -i input.mp4 output.mp4 didn't fix it, but converting to avi did, showing thumbnail and correct resolution. Instead of avi we can change the codec with -c:v mpeg4 to fix it also. I tried -c:v libx264 but didn't work since it already was that codec. So it seems the only way to fix it is to switch codec/format then switch back. Also when first converting we have to use -q:v 0 to not lose quality. ffmpeg -i input.mp4 -c:v mpeg4 -q:v 0 output1.mp4 then ffmpeg -i output1.mp4 output2.mp4.

Also if you do the avi way ffmpeg -i input.mp4 -q:v 0 output1.avi then ffmpeg -i output1.avi output2.mp4, you get the same output2.mp4. They generate the same md5 hash.


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adobe premiere playback lag
Having some trouble with video playback. Was wondering if anyone has settings suggestions to help solve the problem. Just trying to play the project in premiere lags even with the resolution downgraded. Any suggestions would be great.
Computer specs:

Intel Core i7-5820K running @ 4,124 MHz, logical processors 12
2x GeForce GTX 980 cards 4,096 MB in SLI
Memory 32,768 MB @ 2,332 MHz
64-bit Windows 10
M.2 512GB

Video files: 60 fps @ 4096x2048 uncompressed
Nothing spikes, memory runs low and has about 28.9 gigs allocated, processors run low, video cards run low in mem and processors, using mercury. I'm guessing it's some settings that are causing it. I know I'm not using a quarto card which has better drivers for this type if thing ( video drivers are updated ).
Any advice is appreciated,
Thanks!

Uncompressed 4K video at 60fps requires your playback system to deliver approximately 2GB/sec (or more than 15 Gbps).  You can use Blackmagic Design's Disk Speed Test (part of the Desktop Video bundle you can find here) to see whether your system meets this criteria.  If it does not, then you'll need to compress your video until you have a bitrate that your IO system can actually support.

Or get a disk array that is fast enough. Multiple striped ssd should sustain that data rate I guess.

Even the Samsung evo 950 pro m.2 drive, with a read speed of 2200mb/s is dangerously close to the required speed, so I think a 5xsata ssd raid 0 or a 2x m.2 configuration would be safe, speed wise. That is, if you have 5 sata ports (or two m.2 slots)

That is for simple playback only though. If you want to edit that footage in realtime, a simple dissolve will require two streams to be read simultaneously, so 4gb/s.

Thanks! This helped a lot. I'm not on skylake so I'm unable to raid m.2, but I will be needing more space anyways. I ran some test on my internal raid setup and the m.2, they are no where near fast enough. I'm going to look into an external raid 0 ssd array. It seems like then the bottle neck will be data transfer speed. Maybe I can find a usb 3.1 external raid array. Any recommendations for a unit, or experience with solid speedy ssd I usually go with the Samsung 850 Evo ?

I thought I should post some benchmarks encase anyone else comes across the post. This shows my m.2 vs. a 6x HDD Raid 0 speeds. This was not tested properly, I had a lot going on during the test.
https://stlz.s3.amazonaws.com/storage-drive.jpg


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final cut pro x - 1440 x 1080 prevent video stretched to fill in timeline
I have created a FCPx project that is by default 1920 x 1080 however i have some video sources that are 1440 x 1080 the problem becomes when i import the video into the timeline and it stretches the 1440 to 1920 distorting it.
it's similar to this example

 but even in this video it doesn't seem to fix the issue of the video being stretched.
how do i prevent such a thing in FCPx it does seem to not stretch it if the video isn't 1080..
thanks.

I did a test for you and Larry is right ... Normally if the footage or file was anything other than 1440x1080, all you would need to do it set your Spatial Conform to none. However, in this instance FCPX is forcing a size based on the magic 1440 number. To correct this, select your clip and click the drill down triangle under scale in transform. Change just the X: scale to 75% because 1440 is 75% of 1920. That should do it!

Awesome! Keep up the editing!

I was about to post mentioning the Spatial Conform.  I couldn't get it to automatically set the 1440 video back to its original size, without this workaround though.  I was wondering why...

It is just that magic number. It works with every other dimension though (Larry Jordan said something similar, too, in the video posted above).


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What's the difference between 3G-A SDI and 3G-B SDI?
Can someone point me at a description of the difference between a 3G-A SDI signal and a 3G-B SDI signal.
I have a rack with a BlackMagic ATEM 2 M/E Production Studio 4K and a bank of 3 SWT Pro-HD monitors.  The ATEM is set up to run 1080p59.94. The monitors show "No-sync" when fed from the Aux outputs of the ATEM.
If I insert a Decimator MD-HX between the Aux output and the monitor's SDI input, it shows the SDI input to the MD-HX running 3G-B 1920x1080p59.94.
The SDI output of the MD-HX is switchable between 3G-A SDI and 3G-B SDI. Switching he output to 3G-A makes the signal appear on the monitor.
The problem does not appear if I run the ATEM at 720p59.94.
Wikipedia's article on SDI does not mention the A and B variants of SDI.

Wikipedia does mention it - with a reference link included:

Within this standard there are three formats known as Level A, Level B
  Dual Link (B-DL) and Level B Dual Stream (B-DS). The Level A format is
  the direct mapping of uncompressed 1080p (up to 60 fps) video into a
  serial digital interface at the nominal 3 Gbit/s. The Level B-DL
  format is the mapping of dual-link HD-SDI/SMPTE 372M (i.e.: 1080p up
  to 60 fps) in a single serial digital interface at the nominal 3
  Gbit/s. The Level B-DS format is the dual-stream carriage of two
  independent HD-SDI/SMPTE 292M signals (720p up to 60 fps or
  1080i/1080p up to 30 fps) in a single serial digital interface at the
  nominal 3 Gbit/s

The PDF reference has the descriptions starting on pg. 17.


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What is the most appropriate approach/tool in the Adobe CC suite for creating animated diagrams for use in a technical video?
I'm working on a technical video (in Premiere Pro) describing some work we've done in an academic setting, akin to a presentation one might give at a conference. There are recorded video elements that I'd like to overlay with animated diagrams describing how things work.
What's the best way to achieve this kind of thing? I ran across a video tutorial that creates a simple animation using the title creation features of Premiere Pro, but that seems like the wrong tool.
I've got an active CC membership to work with. Maybe I could create a diagram and animation in Animate (previously Flash) and export it as a video, with alpha channel, to overlay. I have limited experience with Flash from years ago. I assume After Effects can do this sort of thing, but I've never worked with it myself. I'm very comfortable in Photoshop and Illustrator since most of my work in CC involves photography and still technical drawing/writing.

After Effects is probably your best bet, as it integrates seamlessly with Premiere and Illustrator.
Create your diagrams in Illustrator, import them into After Effects, and convert them to shape layers. You can then animate them, and add the AE compositions to the Premiere project.


text:
Why is ffmpeg outputting a 600fps video from a 120fps video input?
I have a very short 120fps video.
ffprobe input.mp4 shows 118.99fps:
ffprobe version 3.0 Copyright (c) 2007-2016 the FFmpeg developers
  built with Apple LLVM version 7.3.0 (clang-703.0.29)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/3.0 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --enable-ffplay --enable-vda
  libavutil      55. 17.103 / 55. 17.103
  libavcodec     57. 24.102 / 57. 24.102
  libavformat    57. 25.100 / 57. 25.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 31.100 /  6. 31.100
  libavresample   3.  0.  0 /  3.  0.  0
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
[h264 @ 0x7f8262009600] Increasing reorder buffer to 1
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 1
    compatible_brands: mp41mp42isom
    creation_time   : 2016-04-27 10:43:14
  Duration: 00:00:02.76, start: 0.000000, bitrate: 10318 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 720x1280, 10272 kb/s, 118.99 fps, 600 tbr, 600 tbn, 1200 tbc (default)
    Metadata:
      creation_time   : 2016-04-27 10:43:14
      handler_name    : Core Media Video

I'm running a square crop and resize operation:
ffmpeg -i input.mp4 -vf "crop='if(gte(iw,ih),ih,iw):if(gte(ih,iw),iw,ih)', scale=640x640" -an -c:v libx264 -profile:v high -level 4.1 -preset veryslow -crf 20 output.mp4

This gives:
....
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 1
    compatible_brands: mp41mp42isom
    creation_time   : 2016-04-27 10:43:14
  Duration: 00:00:02.76, start: 0.000000, bitrate: 10318 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 720x1280, 10272 kb/s, 118.99 fps, 600 tbr, 600 tbn, 1200 tbc (default)
....
Output #0, mp4, to 'output.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 1
    compatible_brands: mp41mp42isom
    encoder         : Lavf57.25.100
    Stream #0:0(und): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 640x640, q=-1--1, 600 fps, 19200 tbn, 600 tbc (default)
....

And sure enough, ffprobe output.mp4 confirms that output.mp4 is at 600fps, as does VLC.
How can I ensure that ffmpeg will encode my video using the same framerate as the input (be that 30, 60, 120, or 240fps)?

Update: The PTS entries of the input and output for the command below are identical in version N-79630-g9ac154d. Looks like the file is falsely flagged as VFR. But this single-step command below works for the sample video.
Use
ffmpeg -i input.mp4 -vf "crop='if(gte(iw,ih),ih,iw):if(gte(ih,iw),iw,ih)', scale=640x640" \
   -an -c:v libx264 -profile:v high -level 4.1 -preset veryslow -crf 20 -vsync 0 output.mp4

The framerate stored in the container (tbr) is 600, whereas the reported fps of 118.99 is arrived at by counting the number of video packets and dividing by the total duration. If this is not a variable frame rate stream, then add -r 118.99 as an output option.

For older versions,
Alternatively, output to MKV i.e.
ffmpeg -i input.mp4 -vf "crop='if(gte(iw,ih),ih,iw):if(gte(ih,iw),iw,ih)', scale=640x640" \
   -vsync 0 -an -c:v libx264 -profile:v high -level 4.1 -preset veryslow -crf 20 output.mkv

If you then mux the MKV to MP4,
ffmpeg -i output.mkv -c copy output.mp4

The resulting MP4 will show (close to) the source framerate.
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'no-rc.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.34.103
  Duration: 00:00:02.75, start: 0.000000, bitrate: 2462 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 640x640, 2444 kb/s, 119.88 fps, 600 tbr, 16k tbn (default)

Thanks - the issue with using -r 118.99 is that the input can be at different framerates. Is there a way to make it dynamic so that -r <value> matches the input fps?

Not directly, but yes, if you go through the MKV method as edited.

Cool workaround - it works. I'm going to leave the question open for a couple of days to see if anyone comes up with a one-step process - if not then I'll accept!

If there's a bug, please file one at trac.ffmpeg.org ...


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Issues looping a stream with FFMpeg
I'm trying to overlay a video on top of an image. The problem that I'm facing is that the video duration that I want is longer than my input video's duration.
To solve this issue, I try to generate a streaming loop and hardcode the duration that I want using the parameter "t".
I'm using the setpts filter to make sure that my container format (.mp4) accepts past frames by rewriting their timestamps:
ffmpeg -loop 1 -i image.jpg -stream_loop -1 -i video.mov  -filter_complex "[1:v]setpts=N/(FRAME_RATE*TB)[1v];[0:v][1v]overlay=x=main_w*0.44:y=main_h*0.33[out]" -map [out] -t 00:00:15  out.mp4

So the command reads as follows:

take one infinite input where each frame is image.jpg
take another infinite input (video.mov) by looping (-stream_loop -1)

Each frame will go through the filter:

setpts will re-write the timestamps for source 1 (video.mov)
overlay will put each setpts-ed frame from video.mov on top of each frame from the initial input (image.jpg - 0:v)

This should continue until a file with 00:00:15 seconds is created.
This command does generate that file but the video.mov isn't looped, once the first loop finishes the last frame is repeated until the output movie ends.
FYI: I made a couple more tests:
ffmpeg -stream_loop -1 -i movie.mov -filter_complex "[0:v]setpts=N/(FRAME_RATE*TB)[out]" -map [out] -t 00:00:30 output.mp4

This works fine, it generates a movie with 30 seconds duration with the input movie looped to fill the output movie
on the other hard, if I add one more input file:
ffmpeg -stream_loop -1 -i movie.mov -loop 1 -i image.jpg -filter_complex "[0:v]setpts=N/(FRAME_RATE*TB)[out]" -map [out] -t 00:00:30 output.mp4

This will not create a movie with 30 seconds, although one of the inputs is never used, ffmpeg creates a movie file with just one loop of movie.mov and the same length of movie.mov.
Any advices please ?
Thank you very much!
Ze

Try with the movie filter instead
ffmpeg -loop 1 -i image.jpg -filter_complex \
        "movie=video.mov:loop=999,setpts=N/(FRAME_RATE*TB)[1v]; \
        [0:v][1v]overlay=x=main_w*0.44:y=main_h*0.33[out]" \
       -map [out] -t 00:00:15  out.mp4

Works like a charm! Any idea why stream_loop doesn't work ?

I'm speculating here, but stream_loop value will be registered in the same shared variable as the image demuxer's loop argument, and does not actually get successfully registered. The movie filter creates its own local context. But this is just a guess.


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Transcoding vertical video to an intermediate codec
I used the Android SDK to record some steps for a tutorial video and am having some difficulty working with the footage. First of all, it's of a variable framerate and secondly it's in 1080:1920 - vertical 1080p.
I had hoped to use ffmpeg to transcode to DNxHD but I can't find the right video filter (scale? hflip?) to squeeze it into a resolution that DNxHD supports while retaining the aspect ratio.
I've tried:
ffmpeg -i "recording6.mp4" -vf "scale=-1:1080" -vcodec dnxhd -r 60 -b:v 36M "recording6_DNxHD.mov"

ffmpeg -i "recording6.mp4" -vf "scale=1920:1080" -vcodec dnxhd -r 60 -b:v 36M "recording6_DNxHD.mov"

ffmpeg -i "recording6.mp4" -vf hflip -vcodec dnxhd -r 60 -b:v 36M "recording6_DNxHD.mov"

ffmpeg -i "recording6.mp4" -vf vflip -vcodec dnxhd -r 60 -b:v 36M "recording6_DNxHD.mov"

The first fails because of an unsupported resolution, the second works but changes the aspect ratio, and the third and fourth also fail due to unsupported resolutions.
I realize there are other codecs which are more forgiving than dnxhd in terms of resolution, but I really don't want to lose any detail at this step. So if anyone knows of one which is similarly visually-lossless I'm open to trying it.
Any help you can offer would be much appreciated.

Assuming your editor can rotate videos, use
ffmpeg -i "recording6.mp4" -vf "transpose=1" -vcodec dnxhd -r 60 -b:v 36M "recording6.mov"

This will rotate the video, so the 1080x1920 video becomes 1920x1080.

Hey thanks for your suggestion. Ffmpeg was quite happy to do that conversion, but both Premiere and After Effects (CC with all updates installed) failed to import the newly created file. They both work with other DNxHD files in a quicktime container, so it's probably not a codec issue

What does ffprobe say for the created file?

Not used ffprobe before, so hopefully this is the output you need:
Metadata:
    major_brand: qt
    minor_version: 512
    compatible_brands: qt
    encoder: Lavf57.34.103
Duration: 00:00:25.48, start: 0.000000, bitrate: 90437 kb/s
    Stream #0:0(eng): Video: dnxhd (AVdn / 0x6E645641), yuv422p(tv, bt709/unkown/unknown), 1920x1080, 90439 kb/s, 60 fps, 60tbr, 15360 tbp (default)
Metadata:
    handler_name: DataHandler
    encoder : Lavc57.38.100 dnxhd

I just ran my command on a rotated MP4 I had, and the MOV opened fine in Premiere CC 2015.2 - 9.2.0 (41) and AE CC 2015.2 13.7.0 124 - does your converted file play ok in VLC or QT?

I am an idiot, I was trying to import one of the failed files from Friday in Premiere. The new file created with the transpose filter works perfectly!


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How to record HDMI video output?
How to record HDMI video, which is being sent from a notebook to a projector without interrupting it?
The HDMI signal shows desktop activity and/or video game gameplay on different devices that run Windows, Mac OS X or Linux.

Is it possible to use an HD camcorder with HDMI in and out (example device: Sony HDR PJ620)?
Are there devices with built-in storage or that can write to SATA, USB or SD storage?
Are there devices which can be connected to a second laptop which then records the video?

Hardware/Software solutions that run on/in the computer which outputs the HDMI signal are not relevant. The video-outputting computers can not be manipulated.

I would use three pieces of hardware for this task.

A recording laptop.
A device that allows you to input the HDMI to the recording laptop, aka, a frame grabber.
An HDMI spliter.

A recording laptop
Any old laptop will do, really. It doesn't need super specs, like dedicated graphics, but you certainly want at least a mid-range machine. Like an Intel i5 or better, 8 Gig's RAM, fast HDD (SSD would be great, but not necessary). Software wise, anything that can see the generic devices will work. Pro software like Vegas Pro or Adobe Primere if you have it works great. There's also Wirecast and vMix if you have webcast requirements.
A video frame grabber
I've had pretty good success with the DVI2USB3.0 Frame Grabber by Epiphan. Use that with a DVI to HDMI converter and it will work just fine. It also allows audio capture. I especially like its very small size, solid construction, and that it's USB powered. It will work on USB 2.0, but you will get limited bandwidth in the form of limited framerates per the source resolution (I often get about 45 fps at 1024x768 on USB 2.0). It's a bit on the pricey side, but Epiphan has very good customer service. I know other options are available, but I have no experience with them. About 5 years ago I decided against Black Magic products because of the mixed reviews on Amazon, but that may have gotten better. Other items that are like $10,000 are not the kind of equipment you are looking for. I've never actually seen one of those being used for more than what a $1,000 in hardware can do. Basically, if you don't know why it costs so much, you don't need it.
HDMI video splitter
There are plenty available on the market (Google image search). They're pretty simple. They have a single HDMI input and at least two HDMI outputs, which are both exact duplicates of the input signal. Make sure you get one that is powered because the ones that aren't reduce signal strength and it often shows, especially on projectors (at least, this is true for the VGA splitters). If you intend to audio record over HDMI make sure the splitter you get can handle that.
Setup

Take your source HDMI and run it to the video splitter.
Run an HDMI from an output on the splitter to the projector.
Run an HDMI from an output on the splitter to the Epiphan frame grabber via a DVI to HDMI converter.
Plug the Epiphan USB into the recording laptop.

Alternative, VGA-based setup
I would actually recommend this setup if this is in a professional conference setting and there is a professional audio/visual crew working it. I also recommend this setup if any of the HDMI runs are farther than 30 feet. HDMI just can't push very far and VGA can easily do 100 feet.
If this is a professional setup and you're just hooking in to what they already have, then the projector is not yours and you don't know what to expect. Chances are very high that projector will be gathering it's feed via VGA, not HDMI (you really should call the AV company to find out though).
So instead of using HDMI from the source laptop, use the VGA out (if it has one) or convert it to VGA with an HDMI to VGA dongle. The setup is exactly the same as above except everything HDMI is VGA now, including the VGA video splitter and the DVI to VGA adapter. For audio, just plug into the recording laptop's mic input port. As a warning, you might need some kind of audio cleanup when gathering audio this way. I regularly use the Whirlwind line isolator and the Dsan laptop sound port.
Source
I work for a company that does this all the time. If you need professional help with content production you can find information in my profile.

In the last year, many pros have made the stitch to HDMI and wire tech has gotten very good, allowing for 100 foot runs (longer with extenders), so chances are good now that a professional setting is using all HDMI now. You should still call to check if it's not your set.

I've been seeing sdi lately, converted to hdmi at the source and outputs. Seems over-complicated to me, unless you have to run longer than 100 feet. Regardless, might be worth investing in some hdmi-sdi converters. I like Decimator MD-LX. Black Magic is cheaper, but again, mixed reviews.

This should work:
Hauppauge HD Personal Video Recorder 2 Gaming Edition
Description

The HD Personal Video Recorder 2 Gaming Edition from Hauppauge! allows
  you to record gameplay from your preferred gaming console in Full HD
  1080p video. With HDMI input and output ports as well a component
  video input port, this personal video recorder supports the Xbox 360,
  the Playstation 3 as well as the PC. Also, the no-delay HDMI video
  passthrough allows you to record and play in real time.

You have to connect another computer via USB with a S/W that does the recording. To find similar devices, search for HDMI recorder with passthrough.

Looks like a fun toy. I like that it sends record data over USB, instead of it being internal.

By late 2018, the category "HDMI recorder" (#2 of your 3 questions) has become a commodity.  Passthrough is taken for granted.  Online retailers and auction websites have dozens of models for around USD 100, with new clones appearing every month at half that price.

I personally never had great results with the Hauppage line of products. I would rather; recommend going with a BlackMagic converter box. They make every type imaginable. The BlackMagic H.264 ProRecorder is a fantastic device for the price (under $500); and also does live transcoding to H264, fully adjustable VBR, CBR, and even multiple bitrates. Plus it does live webcasting over livestream and other stream services.  The Hauppage products I've looked at... are toys. Other than the ProRecorder in the 500ish price range, theres nothing that will beat it direct line in to the computer.
Other options would be a KiPro, a Atamos ($2000+ range), or go to an ImagePro III; but you're looking at $15,000.
The BM ProRecorder is fantastic.

About 5 years ago when I was looking into new equipment, I looked at Black Magic. I eventually decided against them because of the mixed reviews on Amazon. Maybe that's changed.

B&H comments for the ProRecorder are a little concerning. Asynchronous audio, won't work with Primere, easily corrupted files, short life ... I couldn't feel good about buying this, but I'm in a professional setting. The content I record represents thousands of dollars.

When you read comments/reviews on B&H, Amazon, etc. consider the fact that the negative reviews are almost all submitted by people who don't know what they are doing or don't know what they are talking about. I own and use many BlackMagic products from small converter gadgets to large video production switchers and 40x40 matrix switchers. With very few exceptions BMD makes cutting-edge products with exceptionally high price/performance ratios.
The H.264 recorder is quite dependent on having a compatible computer configuration and installation to complete the process.

@Richard I personally see a high dependence on computer configuration a pretty big con. If you can control everything and have virtually unlimited prep time, it's no problem, but that's just not usually an option. I can't say I haven't been tempted to buy black magic, and I still might one day. The price is very attractive.

@fredsbend, I agree. My main recorder is an AJA KiPro, and backup recorder is a BlackMagic HyperDeck Studio. Which is why I posted an additional "Answer" about the completely standalone AVerMedia Live Gamer Portable

Based on the experience of Dave Jones (EEVblog) I am ordering an AVerMedia Live Gamer Portable.  It is a small, simple box that records HDMI video up to 1080p directly to an SDHC card.
Ref: http://www.amazon.com/AVerMedia-Recording-Definition-Streaming-C875/dp/B00B2IZ3B0
Ref: https://www.eevblog.com/2014/05/20/tagarno-microscope-recording-success/

You can take a VGA output & convert VGA signal to HDMI by using Kramer VP425, & Record this signal in Atomos Ninja 2 in HD Format. This will give you good quality of audio & video both as Kramer VP435 has sound input.


text:
Does repeatedly saving a video degrade its quality?
I take a video file, let's say an mp4, and use, let's say Windows Movie Maker, to repeatedly just save it, with no edits. Every time, the software has to convert the video into a format it can edit, and then convert it back to an mp4. Will the repeated conversions begin to degrade the video's quality if I do this over and over?

MP4 isn't an ideal format for intermediate saves. If you know you'll be re-opening the file, save it as losslessly as practicable, and use MP4 only for the final output.
That said, depending on the encoder and settings you probably don't lose much if anything on subsequent saves. MP4 and similar codecs work by decimating the higher frequencies (details, resolution) in a predictable way. Once you've saved an MP4 at a particular quality setting you've already discarded the information. If you save again using the same settings, there's no information to lose in the areas that have already lost it.

"If you save again using the same settings, there's no information to lose in the areas that have already lost it." --> Empirically, it doesn't work out this way. If a video is re-encoded at CRF 18 using x264 for 5 cycles, the 1st generation shows a SSIM score of ~99% and the 5th gen, ~98.5%. But for a CRF 23 cycle, 1st gen is ~98.7% and 5th gen is ~97.5%. So more aggressive the compression, faster the drop-off for subsequent encodes.

@Mulvya  Yes, that's why I said "depending on the encoder and settings". Presumably when saving from an NLE for later reopening you're not using a CRF, and you're saving with reasonable quality. Your point is valid, but in practical terms you have to make a lot of passes, and bad decisions, before you actually see any degradation beyond the first loss.

If the codec is not lossless, such as Quicktime Animation Codec; true lossless, then yes.
But if you are using a good encoder, I would gather even after 100 generations of degredation would you be able to even visually see the difference if you continually re-encoded the file outputs using MP4  at a high bitrate- say 30mbps for 1080p.
Lower bitrates, yes.

Yes. By definition, any time you save an audio or video file using a LOSSY compression scheme, you will lose something (by definition).
Now, modern codecs have been getting better at minimizing perceptible losses. But it is always preferable to avoid ANY extra compression steps. Until the project is completely finished and ready for distribution, it is best to keep it in an UNcompressed state.

Yes. Every time you "save" video in video-editor, you will re-render it with codec. Most codecs lose some video information for compression. So, every time you will lose some more information.

All codecs, unless they are truly lossless, suffer from concatenation errors. Every time you encode with a codec, decode, and re-encode with the same or a different codec you will degrade the quality of the video. It isn't as precise to figure out just how bad it will be as when you could count the generational loss of re-recording to tape as the source and destination codecs affect the number of cycles before the artifacts become noticeable.
When you perform an export from most editing software, even if you don't change anything, you go through a full codec cycle. The software internally decodes to its native format and then re-encodes to export. This means that it will interpolate the discarded information.
In my experience, H.264 (the codec used in an MP4 and that is used Windows Movie Maker) exhibits noticeable to the untrained eye concatenation errors after just one codec cycle.

Definitely, it will degrade the video quality after many times of converting. I advise you to convert the file to the one with original settings. The best choice is to use a video editor which allows you to edit and convert files to desired ones.


text:
After Effects - Shape layer obscures graphics layer unless positioned at bottom
I am following an AE tutorial.  As part of its exercise files, the tutorial provides an .ai file that has two layers: a rocket and a black background. The .ai file is then imported into AE as a composition, thereby retaining the two layers.
The tutorial then creates a circle as a shape layer.  It places the shape layer below the rocket but above the background:

and the following is displayed:

When I do the same, the circle obstructs the rocket layer:

The only way I can get the rocket layer to be visible is by moving the circle layer all the way to the vertical bottom:

It's as if the two layers of the original .ai file are behaving as one.  What could be the problem?

Probably a dumb question, but is your circle the same colour as the rocket?
Then it would appear to obscure the rocket...
Alternatively -
There could be some kind of matte on one of the layers?
Click on the Toggle Switches/Modes button at the bottom of the list of layers in the timeline, and see whether any mattes are switched on.

That was it - white on white!  Thank you so much.  Wish I could upvote x10!

No worries at all - if you're ever not sure about something like that, switching the "Mask and Shape Visiblity" button on and off can help to see what's going on.  It's Cmd + Shift + H on a mac (ctrl + shift + H on a PC I assume).

I switched back to white on white to see the effects of toggling "Mask/Shape Visibility".  It did not help.  Sometimes only knowledge from someone experienced as yourself works.  Thank you again. (No wonder BBC production values are high!)


text:
Updrade to Windows 10 34 bit
I want to upgrade Windows 10 32 bit TO Windows 10 64 bit for install Premier Pro CS6 .
How do I upgrade that OS ?

Off-topic here; belongs on Super User.

Off topic but ill chuck in some pointers
1: Backup ALL your data
2: Make sure all your Data is backed up and unplug the external device
3: Reload Windows 10 x64 from the install disk or USB
4: install all your apps again
5: put your data back
6: start editing on your new Windows 10 x64 system


text:
Differences of h.264 and h.265?
What are the main differences between h.264 and h.265?

HEVC (High Efficiency Video Coding),  the new video coding standard brings promise of huge bandwidth savings of approx. 40-45% over H.264 encoded content

More info here

awesome! thanks a lot for this comprehensive comparison! Lots of things make sense to me now; however something that is odd though is that h.264 is actually capable of 4K! Every time I see people talking about 4K it's on the h.265 context even if it requires more computing power; I guess the bandwidth saving makes up for that!

@Raj Is this table something you made yourself, or does it come from somewhere else? If it's the latter maybe you could provide a link.

Sure i will provide a link.

Cheers, useful info. One thing though, can you add some detail on which supports 8-bit vs 10-bit vs 12-bit? As well as colour gamuts supported?

h.265 is obviously more compressed than h.264 and was built for UHD and 4K. Though 1080 files still look great and are even smaller when encoded with h.265 than h.264. Some computers may have trouble with the new codec since it is so new. But, without being too technical, you can think of h.265 and being the new h.264.

Do you expect 265 replacing 264 in the future, as far as web video goes?

I think that's absolutely where the tech is heading, it's just in its infancy now so it will just take a bit longer for everything to catch up.

Basically h.265 uses the same techniques to compress video, it just does it better. The tradeoff for this is that it needs more computing power, especially to compress. So some older machines may struggle with it.


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Using AAC-HE for 5.1 audio?
A couple of questions when thinking about 5.1 audio encoding:

What are the limitations of AAC-HE codec while doing 5.1 audio ?
Why is AC3 preferred when compared to AAC-HE ?

What are the limitations of AAC-HE codec while doing 5.1 audio ?

HE-AAC v2 can only encode stereo from my experience with Nero AAC and the article in Wikipedia about Parametric Stereo.

Why is AC3 preferred when compared to AAC-HE ?

Which case are you actually talking about? Are you sure it's HE-AAC not AAC-LC? Dolby Digital / A/52 / AC-3 was the standard for video DVDs which makes it the most common digital audio format for video. It achieves acceptable quality at significantly less bitrates than the competitor DTS and newer formats developed for video on physical media. AAC-LC is usually offered for official downloads and streaming and is part of the MPEG4 specification.
To add some perspective, HE-AAC was one of the early efforts to develop a codec suitable for low bitrates providing high quality audio compared to earlier speech only audio codecs. Opus is a successor with many improvements in this field and which also offers multichannel capability. Some podcasts offer it as an additional option to Vorbis. It's part of later WebM revisions and can be decoded on recent Android devices but its adoption seems to be very slow. If you are looking for a solution to high quality multichannel audio at low bitrates you should be looking into the state of the art Opus, not old AAC with extentions.
The general recommendation has been to use AAC-LC and to avoid HE features which may cause playback issues on some devices.

on the AC3 prefered to AAC-HE was on the context of 5.1 audio; you answered with the first paragraph as well. Your answer helped clear out some of my doubts thanks!


text:
ffmpeg: can I crop using vf while also using filter_complex at the same time?
I have an ffmpeg command using -vf to square crop a video:
ffmpeg -i input.mp4 -vf \
"crop='if(gte(iw,ih),ih,iw):if(gte(ih,iw),iw,ih)', scale=720x720" \
-an -c:v libx264 -profile:v high -level 4.1 \
-preset superfast -crf 20 output.mp4

I also have a separate ffmpeg command using -filter_complex to apply a slow motion "profile" (normal speed, then slow, then normal speed) to a video:
ffmpeg -i input.mp4 -filter_complex \
"[0:v]trim=0:4.95,setpts=PTS-STARTPTS[v1]; \
 [0:v]trim=4.95:6.75,setpts=PTS-STARTPTS[v2]; \
 [0:v]trim=6.75:8,setpts=PTS-STARTPTS[v3]; \
 [v2]setpts=PTS/0.1[vslow2]; \
 [v1][vslow2][v3]concat=n=3:v=1:a=0[out]" \
-map [out] -an -c:v libx264 -profile:v high -level 4.1 \
-preset superfast -crf 20 -r 30 output.mp4

If I try and put them together:
ffmpeg -i input.mp4 -vf "crop='if(gte(iw,ih),ih,iw):if(gte(ih,iw),iw,ih)', scale=720x720" \
-filter_complex \
"[0:v]trim=0:4.95,setpts=PTS-STARTPTS[v1]; \
 [0:v]trim=4.95:6.75,setpts=PTS-STARTPTS[v2]; \
 [0:v]trim=6.75:8,setpts=PTS-STARTPTS[v3]; \
 [v2]setpts=PTS/0.1[vslow2]; \
 [v1][vslow2][v3]concat=n=3:v=1:a=0[out]" \
-map [out] -an -c:v libx264 -profile:v high -level 4.1 \
-preset superfast -crf 20 -r 30 output.mp4

I then get:
-vf/-af/-filter and -filter_complex cannot be used together for the same stream.

Is there a way of applying the crop filter to the entire stream, or will I have to apply it to each of the [v1], [v2], etc. streams?

Use this:
ffmpeg -i input.mp4  -filter_complex \
"[0:v]crop='if(gte(iw,ih),ih,iw):if(gte(ih,iw),iw,ih)',scale=720x720,split=3[1v][2v][3v]; \
 [1v]trim=0:4.95,setpts=PTS-STARTPTS[v1]; \
 [2v]trim=4.95:6.75,setpts=(PTS-STARTPTS)/0.1[v2]; \
 [3v]trim=6.75:8,setpts=PTS-STARTPTS[v3]; \
 [v1][v2][v3]concat=n=3:v=1:a=0[out]" \
-map [out] -an -c:v libx264 -profile:v high -level 4.1 \
-preset superfast -crf 20 -r 30 output.mp4


text:
How to export a video in expecific ratio
When exporting this video, I get all the content inside the red box. But, I want the content inside green box.
How can I do it in Adobe Premiere?

Go to your sequence settings Sequence>Settings and change the resolution to match the size of the rectangle you want.

When you want to export the media, in the export settings click the button in the video tab that says Match Source, this will set the export resolution to match your timeline. Some codecs (e.g. avid DNxHD) will not allow non-standard resolutions, and most will only allow even numbers of pixels in either dimension (e.g. h.264) so you may have to change codec.


text:
how can we shoot tv show so "tarak mehta ka ulta chasma" it will look like "house of card"?
Hi stackexchange folks.
I need your help.
I want to know that if we want to shoot TV show as following like "house of card" TV show video quality. then what are the changes or steps we need to take. we need to make changes in cameras or video editing ?

Thanks in advance.

Tell us what you are using now. Cameras and your editing process and what programs.

I see four basic differences (in what I believe is the correct priority order):

Lighting.  The lighting on Kevin Spacey is classic three-point lighting with warm fronts, a 2:1 key/fill ratio, and cold back/rim/hair light.  Proper 3-point lighting is the biggest difference between the pro look of episodic television and the amateur look of most YouTube videos.

Resolution.  House of Cards is shot in 5K and mastered in 4K resolution.  You can see it even in greatly scaled down images.
Sensor size/shallow depth of field.  With a large enough image sensor and a large enough lens aperture, it's possible to get crisp focus on the subject and beautiful blur in the background, which as you rightly observe, make you really pay attention to the subject instead of all the many distractions surrounding them.
Set design and wardrobe.  The muted colors (and lower light levels) of the background and the dark suit again focus the viewer on the face and hands (key dramatic communicators) of the actor.  Contrast that with loud colored clothing and bright walls, the eye is overwhelmed with too many subjects to deal with.

Slumdog Millionaire got all this right.  You can, too!


text:
How to remove transitions from title motion adjustments in Premiere Pro?
I am using some motion adjustments (Effect Controls) on title clips placed on top of my video layer in Premiere Pro CC 2015. I change the position of the clips (names) and also change the scaling per 5 frames. But I want a jump effect from one keyframe (of position and scale) to another (after the 5 frames). I don't need a smooth transition.
In other words, I don't need animation but something like different title clips without the need to make them. Can this be done with the motion adjustments or will they always animate between the keyframes?

Set temporal interpolation to Hold as seen below:

You have no idea how helpful it was. I'm new to video editing and this... you just saved my life man... I was thinking of making new titles for all positions, and for all places where I use names. Thanks a bunch!