[Ffmpeg-devel] Re: JPEG-LS codec

Kostya Shishkov kostya.shishkov
Wed Feb 1 12:56:06 CET 2006


>On Wed, 1 Feb 2006 12:05:48 +0100, Michael Niedermayer wrote:<michaelni at gmx.at>
>
>Hi
>
>On Wed, Feb 01, 2006 at 08:51:15AM +0200, Kostya wrote:
>> Now I have JPEG-LS both decoder and encoder. Use FFmpeg "-pred x" option
to set near-lossless compression. Please test and consider for inclusion.
>> Encoder is not relying on MPV_* funcs because MPV_init won't let encode
RGB images, and as I don't need MjpegContext it's easier to write own header
than use mjpeg_picture_header.
>
>tested:
>../ffmpeg_g -y -f pgmyuv -i vsynth1/%02d.pgm -vcodec jpegls -pix_fmt rgb24
./data/a-jpegls.avi
>
>no error messages but image looks like random noise ...
>
>[...]
>
>--
>Michael
I tested it like this:
ffmpeg_g -f image2 -vcodec ppm -i test.ppm -f image2 -vcodec jpegls
output.jls
ffmpeg_g -f image2 -vcodec mjpeg -i output.jls -f image2 -vcodec ppm
output.ppm
I'm not sure if FFmpeg writes avi vcodec tag (and don't know what it should
be - 'MJPG'?) correctly (haven't tested).




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