[FFmpeg-devel] Add waveformat extensible support in wav muxer (SoC qualification task)

[zhentan feng]

Hi

2009/3/30 Michael Niedermayer <michaelni at gmx.at>

> On Mon, Mar 30, 2009 at 12:29:04AM +0800, zhentan feng wrote:
> > Hi
> >
> > 2009/3/29 Michael Niedermayer <michaelni at gmx.at>
> >
> > > On Sun, Mar 29, 2009 at 11:51:57AM +0800, zhentan feng wrote:
> [...]
> > > looks broken when extradata_size is not 0
> > >
> > >
> > thanks and here is the new patch attached below.
> >
> > --
> > Best wishes~
>
> > Index: libavformat/riff.c
> > ===================================================================
> > --- libavformat/riff.c        (revision 18184)
> > +++ libavformat/riff.c        (working copy)
> > @@ -282,12 +282,19 @@
> >  int put_wav_header(ByteIOContext *pb, AVCodecContext *enc)
> >  {
> >      int bps, blkalign, bytespersec;
> > +    int waveformatextensible = 0;
> >      int hdrsize = 18;
> > +    int flg = 0;
> >
> >      if(!enc->codec_tag || enc->codec_tag > 0xffff)
> >          return -1;
> >
> > -    put_le16(pb, enc->codec_tag);
> > +    waveformatextensible = enc->channels > 2 && enc->channel_layout;
> > +    if (waveformatextensible)
> > +        put_le16(pb, 0xfffe);
> > +    else
> > +        put_le16(pb, enc->codec_tag);
> > +
> >      put_le16(pb, enc->channels);
> >      put_le32(pb, enc->sample_rate);
> >      if (enc->codec_id == CODEC_ID_MP2 || enc->codec_id == CODEC_ID_MP3
> || enc->codec_id == CODEC_ID_GSM_MS) {
> > @@ -351,18 +358,35 @@
> >          put_le16(pb, 2); /* wav_extra_size */
> >          hdrsize += 2;
> >          put_le16(pb, enc->frame_size); /* wSamplesPerBlock */
> > -    } else if(enc->extradata_size){
> > -        put_le16(pb, enc->extradata_size);
> > -        put_buffer(pb, enc->extradata, enc->extradata_size);
> > -        hdrsize += enc->extradata_size;
> > -        if(hdrsize&1){
> > -            hdrsize++;
> > -            put_byte(pb, 0);
> > -        }
> > -    } else {
> > -        hdrsize -= 2;
> > +    } else
> > +        flg = 1;
> > +
> > +    if (waveformatextensible) {                     /* write
> WAVEFORMATEXTENSIBLE extensions */
> > +        put_le16(pb, enc->extradata_size+22);       /* 22 is the size of
> WAVEFORMATEXTENSIBLE-WAVEFORMATEX */
> > +        put_le16(pb, enc->bits_per_coded_sample);   /*
> ValidBitsPerSample || SamplesPerBlock || Reserved */
> > +        put_le32(pb, enc->channel_layout);          /* dwChannelMask */
> > +        put_le32(pb, enc->codec_tag);               /* GUID + next 3 */
> > +        put_le32(pb, 0x00100000);
> > +        put_le32(pb, 0xAA000080);
> > +        put_le32(pb, 0x719B3800);
> > +        hdrsize += 22;
> >      }
>
> i doubt this will work when flg != 1
>
> [...]


here is the new patch for version 0.5.
according to get_wav_header() fucntion, write the WAVEFORMATEXTENSIBLE
struct first and update the extrasize if necessary.

-- 
Best wishes~
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