Differences in color between video and saved image from video?

[DavidS]

I have a video that I'm editing for YouTube and the color in the video looks a little off. However, when I do a screengrab from the video or save an image from the video using VirtualDub or AviDemux, the colors look perfect when viewing the still image.

I want the colors in the video itself to match the colors I get from a screengrab of the video.

Why are the colors in the saved image from the video being interpreted differently than the way the video players play the video and what changes should I make to the video to make the colors match up?

I hope the way I phrased this makes sense. I can post some samples if needed to better understand the situation.

Thanks

[jagabo]

Saving a video involves converting YUV video data to RGB image data. There are different ways of doing that. Read up on color matrices:

https://en.wikipedia.org/wiki/Rec._601
https://en.wikipedia.org/wiki/Rec._709

See samples of incorrect conversions here:

https://forum.videohelp.com/threads/329866-incorrect-collor-display-in-video-playback#post2045830

VirtualDub usually uses rec.601. Generally high definition video uses rec.709 and standard definition video rec.601. Youtube assumes rec.709 for both.

Beyond that you have full range and limited range matrices. Digital video mostly uses limited range UV. Computer monitors use full range RGB. Converting between them requires that the matrix convert the range.

Check your graphics card's settings for these options. Also check your media players.

[DavidS]

Saving a video involves converting YUV video data to RGB image data. There are different ways of doing that. Read up on color matrices:

https://en.wikipedia.org/wiki/Rec._601
https://en.wikipedia.org/wiki/Rec._709

See samples of incorrect conversions here:

https://forum.videohelp.com/threads/329866-incorrect-collor-display-in-video-playback#post2045830

VirtualDub usually uses rec.601. Generally high definition video uses rec.709 and standard definition video rec.601. Youtube assumes rec.709 for both.

Beyond that you have full range and limited range matrices. Digital video mostly uses limited range UV. Computer monitors use full range RGB. Converting between them requires that the matrix convert the range.

Check your graphics card's settings for these options. Also check your media players.

It looks like my video is Rec 709 but, by happenstance, I just prefer the colors when decoded using Rec 601. I want to keep my video Rec 709 but emulate the colors that VD displays when decoding using Rec 601.

I'm wondering if there's some simple conversion for my video rather than meticulously tinkering with the colors to try to achieve the same look.

In other words I want to keep my video Rec 709 and decoded using Rec 709, but have YouTube display it with similar or identical colors to the way VD displays it when decoding it using Rec 601.

Thanks

[poisondeathray]

in vdub2 you should be able to use the alias format filter, set it to Rec.601(SD)

In the x264 configuration options (bundled with vdub2 under video=>compression), you can flag the file as 709 by entering in the extra commandline box.

--colorprim bt709 --transfer bt709 --colormatrix bt709

In mediainfo , the flags will show up as

Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

The flags do not affect YT behaviour, but it can help some software and hardware players choose "709", and it doesn't hurt

vdub2 can save as mp4/mkv/mov/avi under file=>save video "save as type"

[DavidS]

in vdub2 you should be able to use the alias format filter, set it to Rec.601(SD)

In the x264 configuration options (bundled with vdub2 under video=>compression), you can flag the file as 709 by entering in the extra commandline box.

--colorprim bt709 --transfer bt709 --colormatrix bt709

In mediainfo , the flags will show up as

Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

The flags do not affect YT behaviour, but it can help some software and hardware players choose "709", and it doesn't hurt

vdub2 can save as mp4/mkv/mov/avi under file=>save video "save as type"

When I select "601" under the alias format filter, it shows up as "alias format (601,same)". When I save the video, I don't notice any difference in the colors from the original video.. I'm guessing the "same" means that no change is being made?

When I choose "709", it also shows "alias format (709,same)". So, I'm not sure what "same" means here.

Thanks

[poisondeathray]

How are you checking the colors ?

The second entry "same" refers to the component range, full vs limited . Most videos will be limited range, so it should be "same"

It makes an immediate difference in the preview for me, and the encoded video has colors shifted

[poisondeathray]

I made a video from the "worse" image in this thread, using 709 to convert back to YUV . It's attached below as "worse.mp4"
https://forum.videohelp.com/threads/408373-Differences-in-color-between-video-and-save...eo#post2679289

I went through the vdub2 aliasformat filter to convert in YUV to 601 , and flagged it as 709

This is what it looks like when it's converted to RGB for display using 709 (it should look like that in a media player, or YT in firefox; but it should look "wrong" in vdub classic or the way you have edge setup for YT)

[Attachment 68895 - Click to enlarge]

[DavidS]

I made a video from the "worse" image in this thread, using 709 to convert back to YUV . It's attached below as "worse.mp4"
https://forum.videohelp.com/threads/408373-Differences-in-color-between-video-and-save...eo#post2679289

I went through the vdub2 aliasformat filter to convert in YUV to 601 , and flagged it as 709

This is what it looks like when it's converted to RGB for display using 709 (it should look like that in a media player, or YT in firefox; but it should look "wrong" in vdub classic or the way you have edge setup for YT)

[Attachment 68895 - Click to enlarge]

It worked. Thank you. The problem was that I forgot to set VD to decode the video using Rec 709. Since it defaults to decoding in Rec 601, when I added the alias filter it didn't change anything. After I set it to decode in Rec 709, then the proper conversion was done.

Thanks again.