[FFmpeg-devel] [PATCH] mxfdec: allow container_ul to override codec_ul if codec is A-law

[Tomas Härdin]

On Thu, 2012-09-27 at 00:24 +0200, Marton Balint wrote:
> Fixes some DNXHD files generated by AVID TM, where codec UL was set to A-law
> meanwhile the real audio codec was PCM S16. According to SMPTE RP 224, A-law is
> the default value for sound essence parameters therefore we should handle it
> specially.

Ah yes, I seem to recall reading something like that too.

> Signed-off-by: Marton Balint <cus at passwd.hu>
> ---
>  libavformat/mxfdec.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> index 16b8c12..a503289 100644
> --- a/libavformat/mxfdec.c
> +++ b/libavformat/mxfdec.c
> @@ -1536,7 +1536,8 @@ static int mxf_parse_structural_metadata(MXFContext *mxf)
>              st->need_parsing = AVSTREAM_PARSE_HEADERS;
>          } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
>              container_ul = mxf_get_codec_ul(mxf_sound_essence_container_uls, essence_container_ul);
> -            if (st->codec->codec_id == AV_CODEC_ID_NONE)
> +            /* Only overwrite existing codec ID if it is unset or A-law, which is the default according to SMPTE RP 224. */
> +            if (st->codec->codec_id == AV_CODEC_ID_NONE || (st->codec->codec_id == AV_CODEC_ID_PCM_ALAW && container_ul->id != AV_CODEC_ID_NONE))
>                  st->codec->codec_id = container_ul->id;

Looks fine.

/Tomas