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.
