New issue 114 by thomasur...@thelooklondon.com: RGB DPX frame to Prores  
422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

What steps will reproduce the problem?
1. DPX frame with full RGB values to Prores HQ 422 or 444 encode with ffmbc  
command
2.
3.

What is the expected output? What do you see instead?
I wouldnt expect any colour shift from RGB to YUV or from DPX RGB to Prores  
RGB

What version of the product are you using? On what operating system?
FFmbc 0.7rc7 for Windows (64-bit) 5-Jul-2012
Windows 7 64bit

Please provide any additional information below:

C:\Users\User\Desktop\ffmpeg-PRORES_ENCODING>ffmbc -f image2 -r 25 -i  
JUNK_DPX_TEST\%06d.dpx -vcodec prores -profile hq  
N:\ffmpeg_encodes\output.mov
FFmbc version 0.7-rc7
Copyright (c) 2008-2012 Baptiste Coudurier and the FFmpeg developers
Input #0, image2, from 'JUNK_DPX_TEST\%06d.dpx':
   Duration: 00:00:40.04, start: 0.000000, bitrate: N/A
     Stream #0.0(und): Video: dpx, rgb48le, 1920x1080p [PAR 65536:65536 DAR  
16:9], 25.00 fps
File 'N:\ffmpeg_encodes\output.mov' already exists. Overwrite ? [y/N] y
Incompatible pixel format 'rgb48le' for codec 'prores', auto-selecting  
format 'yuv422p10le'
[scale @ 0000000001AFD200] w:1920 h:1080 fmt:rgb48le -> w:1920 h:1080  
fmt:yuv422p10le flags:0x4
Output #0, mov, to 'N:\ffmpeg_encodes\output.mov':
   Metadata:
     encoder: FFmbc 0.7
     Stream #0.0(und): Video: prores, yuv422p10le, 1920x1080p [PAR 1:1 DAR  
16:9], 183500 kb/s, 25.00 fps
Stream mapping:
   Stream #0.0 -> #0.0
Press [q] to stop, [?] for help
frame=  256 fps= 19 q=1.0 size=   10534kB time=00:00:10.24  
bitrate=8427.5kbits/s eta=00:00:39.63

Attachments:
        prores422.jpg  1.0 MB
        dpx.jpg  507 KB

Comment #1 on issue 114 by thomasur...@thelooklondon.com: RGB DPX frame to  
Prores 422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

This actually seems to be effecting a conversion from DPX to rawvideo 422  
QT as well

Comment #2 on issue 114 by baptiste...@gmail.com: RGB DPX frame to Prores  
422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

I will need the original dpx to reproduce

Comment #3 on issue 114 by thomasur...@thelooklondon.com: RGB DPX frame to  
Prores 422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

Here you go Baptiste.  If you convert this frame to a QT and then compare  
the colour you'll see the output gets slighter warmer.  Have tried adding  
-vf colormatrix=bt709:bt709 with no change.

Attachments:
        dpx.dpx  3.5 MB

Comment #4 on issue 114 by baptiste...@gmail.com: RGB DPX frame to Prores  
422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

Hummm, djv and imagemagick cannot convert this dpx, their output is a black  
frame.
What are you using to view and create the dpx ?

Comment #5 on issue 114 by thomasur...@thelooklondon.com: RGB DPX frame to  
Prores 422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

That was from a Quantel Pablo, this one is from SGO Mistika, be aware the  
frame is very dark

Attachments:
        001000.dpx.zip  3.3 MB

Comment #6 on issue 114 by thomasur...@thelooklondon.com: RGB DPX frame to  
Prores 422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

Having now also done a Uncompressed YUV422 QT to Prores I also get the same  
shift.  I think this is the same as this issue:  
http://web.archiveorange.com/archive/v/DUtyPyCWLv29zJqkZkPl
Maybe as we're in a colour critical environment we pick up on this when  
others dont care, however this means ffmpeg can not be used for true 1:1  
color critical work.  A snapshot of our scope shows a change in the RGB  
parade (the last three).  The Red and Blue channel is different,  
unfortunately i cant upload these as this forum says the storage quota for  
this thread is exceeded.  Thanks

Comment #7 on issue 114 by jakub.kr...@gmail.com: RGB DPX frame to Prores  
422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

Hey guys, I can confirm that we at Weta are experiencing the same issue. I  
have the latest ffmpeg and ffmbc versions compiled and i've ran a few tests  
encoding a dpx sequence into a prores quicktime. We're trying to find a  
replacement for our current in-house solution that runs only on mac os x  
and uses native quicktime libraries (we are finding the code maintenance to  
be very difficult, which is why we are wanting to find an alternative) and  
i can generate an awesome looking prores movie, but as OP posted, it is  
more yellow than the source. There is a definite color shift. The quality  
of the video and encoding is better (prores HQ, 48fps, 2k res, yuv44410p,  
170Mbit data rate) and the codec we use ATM (apple intermediate), but the  
color is off.

I'd be happy to provide some dpx's and resulting sequences generated with  
our in house solution vs. ffmpeg for comparison if this could help solve  
the problem...

thanks
jakub

Comment #8 on issue 114 by baptiste...@gmail.com: RGB DPX frame to Prores  
422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

Humm, the other frame looks plain black to me, I cannot distinguish  
anything.
I'll close this issue unless a good dpx file is supplied that clearly  
illustrates the problem,
I just cannot fix anything without a good test case

Comment #9 on issue 114 by flehnerh...@gmail.com: RGB DPX frame to Prores  
422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

I have noticed some of the same symptoms. If the limit of attachments  
hadn't been full I'd attached an archive with two dpx'es, two quicktimes,  
and two screenshots from video scopes in FCP. I know it's not the most  
accurate, but our hardware video scope confirms the shift.

I'll try emailing you the archive :)

Commands used to produce quicktimes:

ffmbc -i calibrate.%04d.dpx -r 25 -vcodec prores -profile std -vf  
colormatrix=bt601:bt709 -y dpx_to_prores_709_filtering.mov

ffmbc -i calibrate.%04d.dpx -r 25 -vcodec prores -profile std -y  
dpx_to_prores_no_filtering.mov

Comment #10 on issue 114 by thomasur...@thelooklondon.com: RGB DPX frame to  
Prores 422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

I've uploaded a kodak marcie(rec709) dpx and its converted to prores 422  
output, and a split screen as a tiff Baptiste. I've shared the files with  
you via your gmail account.
Hopefully this will clearly show you the issue.  Its clear that the guys at  
Weta have the same problem and they know what they're doing!
Best regards

Comment #11 on issue 114 by thomasur...@thelooklondon.com: RGB DPX frame to  
Prores 422/444 HQ produces colour shift to yellow
http://code.google.com/p/ffmbc/issues/detail?id=114

Has this topic now been closed?