[vlc-devel] [RFC] Remove SDL_image codec plugin?

[Marvin Scholz]

Hi,

I was wondering if we can remove the SDL_image codec module (and 
therefore the SDL and
SDL_image dependencies in contrib) as it seems most formats are 
supported anyway by
ffmpeg and others seems very obscure and possibly too niche to justify 
depending on
SDL just for those:

     { VLC_CODEC_TARGA, "TGA" }, -> supported by FFmpeg
     { VLC_CODEC_BMP, "BMP" }, -> supported by FFmpeg (but see below)
     { VLC_CODEC_PNM, "PNM" }, -> supported by FFmpeg
     { VLC_FOURCC('x','p','m',' '), "XPM" }, -> supported by FFmpeg
     { VLC_FOURCC('x','c','f',' '), "XCF" }, -> as far as I can see not 
supported by FFmpeg
     { VLC_CODEC_PCX, "PCX" }, -> supported by FFmpeg
     { VLC_CODEC_GIF, "GIF" }, -> supported by FFmpeg
     { VLC_CODEC_JPEG, "JPG" }, -> supported by FFmpeg
     { VLC_CODEC_TIFF, "TIF" }, -> supported by FFmpeg
     { VLC_FOURCC('l','b','m',' '), "LBM" }, -> unsure if supported by 
FFmpeg
     { VLC_CODEC_PNG, "PNG" } -> supported by FFmpeg

The most worrying seems the comment in subsusf:

                     /* Find a suitable decoder module */
                     if( module_exists( "sdl_image" ) )
                     {
                         /* ffmpeg thinks it can handle bmp properly but 
it can't (at least
                          * not all of them), so use sdl_image if it is 
available */
                         var_Create( p_dec, "codec", VLC_VAR_STRING | 
VLC_VAR_DOINHERIT );
                         var_SetString( p_dec, "codec", "sdl_image" );
                     }

so it might be needed in some special corner-cases but unfortunately its 
not
documented what these specific BMPs are that ffmpeg can not handle so I 
am
not sure how we could test if its still needed.

If we come to the conclusion it is still needed indeed, we should at 
least update
it to SDL2 / SDL2_image instead of the ancient versions we currently 
use.

Any opinion/insight from people more familiar with these codecs would be 
highly
appreciated!