[FFmpeg-devel] [PATCH] RealMedia muxer: support audio codecs other than AC-3

[Francesco Lavra]

On Sun, 2010-05-09 at 22:56 +0200, Michael Niedermayer wrote:
> [...]
> >  utils.c |   29 ++++++++++++++++++++++++-----
> >  1 file changed, 24 insertions(+), 5 deletions(-)
> > ac17a932410847e0eac6b42bd8a7184ed2ec522a  02_utils.patch
> > Index: libavformat/utils.c
> > ===================================================================
> > --- libavformat/utils.c	(revision 23062)
> > +++ libavformat/utils.c	(working copy)
> > @@ -2023,30 +2023,49 @@
> >      return ret;
> >  }
> >  
> > -unsigned int ff_codec_get_tag(const AVCodecTag *tags, int id)
> > +static const AVCodecTag *find_avcodectag_from_id(const AVCodecTag *tags, int id)
> >  {
> >      while (tags->id != CODEC_ID_NONE) {
> >          if (tags->id == id)
> > -            return tags->tag;
> > +            return tags;
> >          tags++;
> >      }
> >      return 0;
> >  }
> >  
> > -enum CodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
> > +static const AVCodecTag *find_avcodectag_from_tag(const AVCodecTag *tags,
> > +                                                  unsigned int tag)
> >  {
> >      int i;
> >      for(i=0; tags[i].id != CODEC_ID_NONE;i++) {
> >          if(tag == tags[i].tag)
> > -            return tags[i].id;
> > +            return tags + i;
> >      }
> >      for(i=0; tags[i].id != CODEC_ID_NONE; i++) {
> >          if(   toupper((tag >> 0)&0xFF) == toupper((tags[i].tag >> 0)&0xFF)
> >             && toupper((tag >> 8)&0xFF) == toupper((tags[i].tag >> 8)&0xFF)
> >             && toupper((tag >>16)&0xFF) == toupper((tags[i].tag >>16)&0xFF)
> >             && toupper((tag >>24)&0xFF) == toupper((tags[i].tag >>24)&0xFF))
> > -            return tags[i].id;
> > +            return tags + i;
> >      }
> > +    return 0;
> 
> return NULL

Fixed, although patcheck doesn't like NULLs. Likewise, changed
find_avcodectag_from_id() too.

> >  utils.c |   56 +++++++++++++++++++++++++++++++++++++++++++++++++++-----
> >  1 file changed, 51 insertions(+), 5 deletions(-)
> > 21388c149c24ae10c10565ce74cf1d75005e1f95  03_utils.patch
> > Index: libavformat/utils.c
> > ===================================================================
> > --- libavformat/utils.c	(revision 23062)
> > +++ libavformat/utils.c	(working copy)
> > @@ -2594,6 +2594,51 @@
> >      return 0;
> >  }
> >  
> > +static int validate_codec_tag(AVFormatContext *s, AVStream *st)
> > +{
> > +    const AVCodecTag *avctag;
> > +    int n;
> > +    enum CodecID id = CODEC_ID_NONE;
> > +    unsigned int tag = 0;
> > +
> > +    /**
> > +     * Check that tag + id is in the table
> > +     * If neither is in the table -> OK
> > +     * If tag is in the table with another id -> FAIL
> > +     * If id is in the table with another tag -> FAIL unless strict < normal
> > +     */
> > +    for (n = 0; s->oformat->codec_tag[n]; n++) {
> 
> > +        avctag = find_avcodectag_from_tag(s->oformat->codec_tag[n],
> > +                                          st->codec->codec_tag);
> > +        while (avctag) {
> > +            id = avctag->id;
> > +            if (id == st->codec->codec_id)
> > +                break;
> > +            avctag = find_avcodectag_from_tag(avctag + 1, st->codec->codec_tag);
> > +        }
> > +        if (id == st->codec->codec_id)
> > +            break;
> 
> a goto would simplify this

Simplified even further without goto.

> besides, iam not sure if it wouldnt be  simpler to just write a loop that
> goes over all AVCodecTag and compares id and tag instead of trying to use 
> find_avcodectag_from_tag() ...

B_utils.patch contains an alternative implementation which doesn't
require find_avcodectag_from_tag() and find_avcodectag_from_id().
Both options A (A_01_utils.patch + A_02_utils.patch) and B
(B_utils.patch) pass regression tests and FATE.