[FFmpeg-devel] [PATCH] Allow setting mode MONO in libmp3lame if the library is greater than 3.97

[Aurelien Jacobs]

On Thu, Aug 12, 2010 at 10:33:02PM -0700, Thierry Foucu wrote:
> Hi,
> 
> for a while we are using lame 3.97+ in mono and stereo mode in mencoder, and
> I noticed that ffmpeg sets always the mode to JOINT_STEREO.
> 
> The patch will check lame version and if greater then 3.97, it will set the
> mode to MONO or JOINT_STEREO
> 
> Index: libavcodec/libmp3lame.c
> ===================================================================
> --- libavcodec/libmp3lame.c (revision 24791)
> +++ libavcodec/libmp3lame.c (working copy)
> @@ -55,8 +55,18 @@
>      } else {
>          lame_set_quality(s->gfp, avctx->compression_level);
>      }
> -    /* lame 3.91 doesn't work in mono */
> -    lame_set_mode(s->gfp, JOINT_STEREO);
> +    lame_version_t lame_version;
> +    get_lame_version_numerical(&lame_version);
> +    if (lame_version.major <= 3 && lame_version.minor < 97) {
> +        /* lame 3.91 doesn't work in mono */
> +        lame_set_mode(s->gfp, JOINT_STEREO);
> +    } else {

> +        if (s->stereo) {
> +          lame_set_mode(s->gfp, JOINT_STEREO);
> +        } else {
> +          lame_set_mode(s->gfp, MONO);
> +        }

Inconsistent indentation, and it would be simpler this way:
  lame_set_mode(s->gfp, s->stereo ? JOINT_STEREO : MONO);

Aurel