[Ffmpeg-devel] help on forcing rgb555 with 16bpp
Tue Oct 24 13:57:59 CEST 2006
On Tue, Oct 24, 2006 at 04:25:29AM -0300, Reynaldo H. Verdejo Pinochet wrote:
> Hi folks
> Im a little confused by the way raw.c chooses PIX_FMT using the
> bits_per_sample value. Looking at the raw_init_decoder function, how
> am I supossed to get my data interpreted as rgb555 by the raw
> decoder if:
> 1.- bits per sample is 16bpp.
> 2.- I have no mapping for the packed PIX_FMT_RGB555 on pixelFormatTags.
find a sechole in lavc and exploit it and change the pix_fmt ;)
> I'm thinking there is need to add RGB mappings to pixelFormatTags. If
yes or set bits per sample to 15
> that's true how do i choose a tag? Should I just invent some? And last
> but not least, why does the raw decoder choose PIX_FMT using bpp if there
> are packed formats that share that bitcount (ie RGB565 RGB555) ?
because AVI uses the same codec_tag for all rgb variants
the problem is the silly design of avi ...
setting the pix_fmt in avi alone doesnt help at all, as muxers generally dont
use the pix_fmt and making all demuxers and muxers set/get the pix_fmt would
likely be far too messy (and then the same would have to be done with audio)
setting a fake codec_tag in avidec.c would be an easy and simple solution ...
having a codec_id per pix_fmt would be another one but that too would
likely become messy
also look at the mailinglist archives this was disscussed already a few
times but noone posted any acceptable patches to fix it
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
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