[FFmpeg-devel] [PATCH] List supported pixel formats

[Stefano Sabatini]

On date Monday 2007-05-28 01:08:13 +0200, Michael Niedermayer encoded:
> Hi
> 
> On Sat, May 26, 2007 at 03:36:49PM +0200, Stefano Sabatini wrote:
> > Hi.
> > 
> > On date Friday 2007-05-25 19:45:43 +0200, Michael Niedermayer encoded:
> > > Hi
> > > 
> > > On Fri, May 25, 2007 at 05:46:35PM +0200, Stefano Sabatini wrote:
> > > > Hi dear ffmpeg developers.
> > > > 
> > > > This patch is based on a patch recently posted by Panagiotis (see
> > > > "List compiled in codecs"), and applies the same functionality and
> > > > interface to -pix_fmt.
> > > > 
> > > > In order to get ffmpeg able to list the pixel formats the patch does what follows:
> > > > 
> > > > * move the PixFmtInfo structure definition from
> > > >   libavcodec/imgconvert.c to libavcodec/avcodec.h
> > > > 
> > > > * declare as extern in avcodec.h the structure pix_fmt_info containing
> > > >   all the pixel formats infos.
> > > 
> > > rejected this struct array is unfit to be exported like that
> > > adding a field to the struct would break compatibility ...
> > 
> > Got it.
> > 
> > What about to define a list_pix_fmts() function in
> > libavcodec/imgconvert.c and export its interface in
> > libavcodec/avcodec.h?
> 
> hmm, maybe outputing a string similar to avcodec_string() would
> be more flexible ...

The following patch creates a new function in libavcodec/imgconvert.c: 
avcodec_pix_fmt_string (buf, buf_size, pix_fmt)

modeled after avcodec_string(...), and exported in
libavcodec/avcodec.h.

The resulting (admittedly rather ugly) ffmpeg -pix_fmt list output is:

sds at santefisi:~/src/ffmpeg-snapshot$ ./ffmpeg -pix_fmt list
FFmpeg version SVN-r9143, Copyright (c) 2000-2007 Fabrice Bellard, et al.
  configuration: --prefix=/home/sds --mandir=/home/sds/share/man --enable-gpl --enable-swscaler --enable-pp
  libavutil version: 49.4.0
  libavcodec version: 51.40.4
  libavformat version: 51.12.1
  built on May 28 2007 18:12:02, gcc: 4.1.2 20061028 (prerelease) (Debian 4.1.1-19)
name=     yuv420p, nb_channels=   3, depth=   8, is_alpha=n
name=     yuyv422, nb_channels=   1, depth=   8, is_alpha=n
name=       rgb24, nb_channels=   3, depth=   8, is_alpha=n
name=       bgr24, nb_channels=   3, depth=   8, is_alpha=n
name=     yuv422p, nb_channels=   3, depth=   8, is_alpha=n
name=     yuv444p, nb_channels=   3, depth=   8, is_alpha=n
name=       rgb32, nb_channels=   4, depth=   8, is_alpha=y
name=     yuv410p, nb_channels=   3, depth=   8, is_alpha=n
name=     yuv411p, nb_channels=   3, depth=   8, is_alpha=n
name=      rgb565, nb_channels=   3, depth=   5, is_alpha=n
name=      rgb555, nb_channels=   3, depth=   5, is_alpha=n
name=        gray, nb_channels=   1, depth=   8, is_alpha=n
name=       monow, nb_channels=   1, depth=   1, is_alpha=n
name=       monob, nb_channels=   1, depth=   1, is_alpha=n
name=        pal8, nb_channels=   4, depth=   8, is_alpha=y
name=    yuvj420p, nb_channels=   3, depth=   8, is_alpha=n
name=    yuvj422p, nb_channels=   3, depth=   8, is_alpha=n
name=    yuvj444p, nb_channels=   3, depth=   8, is_alpha=n
name=      xvmcmc, nb_channels=   0, depth=   0, is_alpha=n
name=    xvmcidct, nb_channels=   0, depth=   0, is_alpha=n
name=     uyvy422, nb_channels=   1, depth=   8, is_alpha=n
name=   uyyvyy411, nb_channels=   1, depth=   8, is_alpha=n
name=       bgr32, nb_channels=   4, depth=   8, is_alpha=y
name=      bgr565, nb_channels=   3, depth=   5, is_alpha=n
name=      bgr555, nb_channels=   3, depth=   5, is_alpha=n
name=        bgr8, nb_channels=   1, depth=   8, is_alpha=n
name=        bgr4, nb_channels=   1, depth=   4, is_alpha=n
name=   bgr4_byte, nb_channels=   1, depth=   8, is_alpha=n
name=        rgb8, nb_channels=   1, depth=   8, is_alpha=n
name=        rgb4, nb_channels=   1, depth=   4, is_alpha=n
name=   rgb4_byte, nb_channels=   1, depth=   8, is_alpha=n
name=        nv12, nb_channels=   2, depth=   8, is_alpha=n
name=        nv12, nb_channels=   2, depth=   8, is_alpha=n
name=     rgb32_1, nb_channels=   4, depth=   8, is_alpha=y
name=     bgr32_1, nb_channels=   4, depth=   8, is_alpha=y
name=    gray16be, nb_channels=   1, depth=  16, is_alpha=n
name=    gray16le, nb_channels=   1, depth=  16, is_alpha=n

The corresponding format is defined in avcodec_pix_fmt_string as follows:
snprintf (buf, buf_size,
         "name=%12s, nb_channels=%4d, depth=%4d, is_alpha=%c",
         info.name,
         info.nb_channels,
         info.depth,
         is_alpha_char
    );

I'd like to add a similiar functionality for other options as well
(namely: sizes, sws_flags, protocols, codecs) so this format should
result somehow compatible with the other ones. 

Any idea for improving this format?

Regards
-- 
Stefano Sabatini
Linux user number 337176 (see http://counter.li.org)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: list-pix-fmt-01.patch
Type: text/x-diff
Size: 3973 bytes
Desc: not available
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20070529/4f4ed8a4/attachment.patch>