DxDiag.txt (98.0 KB)
I have noticed, on several occassions, that there’s a shift in color between the source (Blu-Ray) and what TVAI makes of it. To wit:
And:
The output goes to ProRes 422 HQ.
While the difference is not huge, it’s definitely noticeable.
I think the color conversion error between BT601 and BT709 is recurring.
I made a sample batch file, so if what is 4K_601.mov outputs the same tint, then it is a color conversion error.
BT601BT709Test.ZIP (497 Bytes)
Original(BT709)
TVAI 2x Scale(BT709 → rgb → BT709)
TVAI 2x Scale(BT709 → rgb → BT601) error
Hey y’all,
These color issues are something our developers are aware of, we’re investigating right now. Thanks for uploading your screenshots!
@TicoRodriguez & @meimeiriver Can you both share the input and output file with me via DropBox?
You can securely submit your files(s) to our Dropbox using the link below. Please be sure to send me a note to let me know you sent something.
I just checked a recent output .mov file; it’s encoded as BT.709 (as it should be). Far as I see it, nothing TVAI does should ever be converted to BT.601, as that is just for SD material.
If this is the same bug that was happening before, then the following is happening
TVAI is processed within the rgb48 (R:G:B 16bit) color format.
Since general videos are made in YUV, the processing is YUV(input) → RGB(TVAI) → YUV(output).
YUV(601 or 709…) ->RGB is done properly, but for RGB->YUV, 601 is applied unless you explicitly set it in the options. As the meta tag is 701, the decoding will be wrong.
https://trac.ffmpeg.org/wiki/colorspace
The following is the portion of the sample batch file uploaded last time that relates to the BT709 conversion.
tvai_up=device=-2:model=prob-3:scale=2:compression=0.24:details=0.24:blur=0:noise=0.12:halo=0:preblur=0,scale=w=3840:h=2160:out_color_matrix=bt709
Another example (from 2010 – The Year We Make Contact)
I dropped a sample of the movie into your dropbox.
What title did you upload the file with?
I already deleted the sample, but the file had ‘2010’ in the name.
We are close to a solution and I appreciate you all taking the time to share files with me that allow us to reproduce this issue. If you have other examples, please label them as color shift issue and your name and upload them using the link below.
You can securely submit your files(s) to our Dropbox using the link below. Please be sure to send me a note to let me know you sent something.
I tested VEAI for color fidelity.
I used the Avisynth script, which created RGB, RGB64, YUV420, etc. clips from a standard MP4 file with basic colors.
I used Chronos filter 30->60fps. ProRes output.
Each resulting file had slightly changed colors, the worst in the case of RGB.
Why is this happening? I understand a slight color change, but here the result was different depending on the color space used, even though the colors were the same.
Hello and thank you for this detailed bug report.
Our dev team is aware of some situations where the app is creating a colorspace transformation between the input and output files, and we are actively looking into an internal change which will resolve this issue. If you have any sample files you’d like me to pass along to the team working on this you can securely submit your file(s) to our Dropbox using the link below. Please be sure to send me a note to let me know you sent something.
Hello Tony,
could you give us an update on this issue and information when can we expect this to be resolved?
This is a major dealbreaker for our workflow and we don’t feel good about this major issue being known to your team and not addressed yet.
We don’t have a timeline for when an update will be released to address colorspace transformation issues in the app but our developers are prioritizing this issue and looking into options for supporting more color format in future versions of Video AI.
I looked through our Dropbox and could not find a sample file from this thread, could you link it directly here? Thanks
Thank you for responding so quickly Tony. I’ll follow with some more information about the issue, perhaps helpful for others in this thread and for your team.
In our workflow we export Prores 422 files from AE (PC/MAC), then enhance them in Topaz (PC) and export to Prores 422 HQ again, and then import them again to AE.
What we’ve noticed is that after importing the Topaz mov into AE on PC, the colors are shifted, however on AE MAC the colors are the same.
When we checked the detailed info about Topaz mov against the original mov from AE we noticed that some elements got changed and that Topaz removed last frame in the file. It seems that PCs have problem with properly interpreting movs from Topaz, while Macs interpret them correctly. I’ll attach the screenshot from the MediaInfo app here and on Dropbox.
