FF_ALPHA_TRANSP  2736 libavcodec/imgconvert.c                 ret |= FF_ALPHA_TRANSP;
FF_ALPHA_TRANSP  2766 libavcodec/imgconvert.c         ret = FF_ALPHA_TRANSP | FF_ALPHA_SEMI_TRANSP;
FF_ALPHA_TRANSP   855 libavcodec/imgconvert_template.c                 ret |= FF_ALPHA_TRANSP;