[Ffmpeg-devel] raw video support in quicktime wrongly assumes raw audio

[Tomas Stenlund]

Hi,

I'm having a question regarding the quicktime support for 'raw ', fourcc.
I got the following output when I tried to convert a quicktime movie (fourcc
is 'raw ' and the file contains one single video "trak") to quicktime
movie (h263).

ffmpeg -vstats -ps 1000 -i /home/etomste/Desktop/QTC_UM_1898.mov -s qcif -vcodec h263 -r 15 -b 50k ./test.mov

FFmpeg version SVN-r6868, Copyright (c) 2000-2006 Fabrice Bellard, et al.
  configuration:
  libavutil version: 49.0.2
  libavcodec version: 51.24.0
  libavformat version: 51.6.0
  built on Nov  3 2006 12:51:47, gcc: 4.0.3 (Ubuntu 4.0.3-1ubuntu5)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/etomste/Desktop/QTC_UM_1898.mov':
  Duration: 00:00:18.6, start: 0.000000, bitrate: 9124 kb/s
  Stream #0.0(eng): Audio: pcm_u8, 176 Hz, 0 channels
File './test.mov' already exists. Overwrite ? [y/N] y
Output #0, mov, to './test.mov':
  Stream #0.0: Audio: 0x0000, 176 Hz, 0 channels, 64 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
Unsupported codec for output stream #0.0

So it assumes, wrongly, that this is an audio codec.

When I looked at the sourcecode for mov.c I found out that the 'raw ' support
for video was commented out and that the mov_read_stsd always tried the
audio fourcc before the video regardless of what the hdlr header said. So
the 'raw ' exists for both video and audio codec.

I'm completely new to the ffmpeg architecture and how you want to solve
things but it was pretty simple to add this support so it worked for me. I added
support for 'raw ' in mov.c and used the hdlr information if available in
the stsd reader and mapped 'raw ' to RGB24 format in the raw.c.

But I'm not certain that my solution is any good since I am not really sure
what 'raw ' actually means. For me it works with RGB24 as pixel format. But I
have not found any information on 'raw ' and what it actually stands for so
I'm beginning to understand why support for it was commented out earlier.

Comments ?

Thanks,

Tomas