[x264-devel] x264-devel Digest, Vol 47, Issue 11

[Kieran Kunhya]

> From: x264-devel-request at videolan.org
> Subject: x264-devel Digest, Vol 47, Issue 11
> To: x264-devel at videolan.org
> Date: Mon, 18 Apr 2011 12:00:04 +0200
> 
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> Today's Topics:
> 
>    1. yuvj420p colorspace (Aurius Bendikas)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Sat, 16 Apr 2011 18:47:50 +0300
> From: Aurius Bendikas <aurius.bendikas at gmail.com>
> To: x264-devel at videolan.org
> Subject: [x264-devel] yuvj420p colorspace
> Message-ID: <BANLkTim1M9xHhDiZEpe3k9gSAfE8p3feuw at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
> 
> Hello x264 developers,
> 
> I have a little problem and I hope you could help me. I have a Canon
> 600D photo camera witch produces *.mov video files encoded in H264,
> but uses quite unusual colorspace - yuvj420p. The video bitrate is
> around 46 Mbps, witch is too muctch for my video player to handle, so
> I need to reencode it to 20 Mbps and also make it High at 4.1 compatible
> to be able to play it on my big screen.
> 
> So the problem is when I reencode with x264 I got a warning message:
> 
> bash#:x264 --pass 1 --bitrate 20000 --profile high --preset veryslow
> --level 4.1 --vf crop:0,0,0,8 -o MVI_0108.264 MVI_0108.MOV
> lavf [info]: 1920x1088p 0:1 @ 30000/1001 fps (vfr)
> resize [warning]: converting from yuvj420p to yuv420p
> ....
> 
> When I compare original video with reencoded video, the reencoded
> video looks very flat (much brighter and less contrast).
> 
> When I reencode with ffmpeg, no colorspce convertion is done, and the
> video looks exactly the same as original.
> 
> So my question is can I encode in yuvj420p with x264 encoder? Is this
> supported? Is it planned to be supported?
> 
> I am used to x264 encoder, and it is muctch better docummented than
> ffmpeg. I would like to use it in my workflows in the future.

This happens because your source encoder sets full_range_flag incorrectly. x264cli believes this information and converts from yuvj420p to yuv420p.