[FFmpeg-devel] Issues with ljpeg

Mathieu Malaterre mathieu.malaterre
Wed Aug 27 16:29:27 CEST 2008

2008/8/16 Michael Niedermayer <michaelni at gmx.at>:
> we need a patch that when applied fixes the bug and the regression tests.
> have you tested the RGB32 code? if not please do, i think it is buggy as well
> and iam not going to apply a patch that fixes one function while one above
> is left with the identical bug.
> hint: the &0x1FF

Sorry but I do not understand how I am supposed to access this part of
code. There is not a single line of comment in this file. Is this
where 32bits image get compressed ? That does not even make sense,
since I would just discard the alpha component and reuse the other

I tried anyway with a 32bits RGB png I had on disk:

$ ./ffmpeg -f image2 -i fran_cut.png -f image2 -pred 6 -vcodec ljpeg
Input #0, image2, from 'fran_cut.png':
  Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
    Stream #0.0: Video: png, rgb32, 256x256, 25.00 tb(r)
Output #0, image2, to '/tmp/out6.ljpeg':
    Stream #0.0: Video: ljpeg, rgb32, 256x256, q=2-31, 200 kb/s, 25.00 tb(c)
Stream mapping:
  Stream #0.0 -> #0.0
[ljpeg @ 0xe2e5f0]colorspace not supported in jpeg
Error while opening codec for output stream #0.0 - maybe incorrect
parameters such as bit_rate, rate, width or height

> ljpeg_decode_yuv_scan() amongth other functions

Hum... Looking at the output of -formats there was no mention of a
ljpeg decoder...



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