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

zhentan feng spyfeng
Tue Mar 31 19:45:17 CEST 2009


Hi

2009/3/31 Michael Niedermayer <michaelni at gmx.at>

> On Tue, Mar 31, 2009 at 07:47:59PM +0800, zhentan feng wrote:
> [...]
> > here is 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;
>
> redundant init
>
>
> >      int hdrsize = 18;
> > +    int64_t pos, update_size_pos;
> >
> >      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) {
> > @@ -324,8 +331,22 @@
> >      put_le32(pb, bytespersec); /* bytes per second */
> >      put_le16(pb, blkalign); /* block align */
> >      put_le16(pb, bps); /* bits per sample */
> > +
> > +    if (waveformatextensible) {                     /* write
> WAVEFORMATEXTENSIBLE extensions */
> > +        update_size_pos = url_ftell(pb);
> > +        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;
> > +    }
> > +
> >      if (enc->codec_id == CODEC_ID_MP3) {
> > -        put_le16(pb, 12); /* wav_extra_size */
> > +        if (!waveformatextensible)
> > +            put_le16(pb, 12); /* wav_extra_size */
> >          hdrsize += 12;
> >          put_le16(pb, 1); /* wID */
> >          put_le32(pb, 2); /* fdwFlags */
> > @@ -333,7 +354,8 @@
> >          put_le16(pb, 1); /* nFramesPerBlock */
> >          put_le16(pb, 1393); /* nCodecDelay */
> >      } else if (enc->codec_id == CODEC_ID_MP2) {
> > -        put_le16(pb, 22); /* wav_extra_size */
> > +        if (!waveformatextensible)
> > +            put_le16(pb, 22); /* wav_extra_size */
> >          hdrsize += 22;
> >          put_le16(pb, 2);  /* fwHeadLayer */
> >          put_le32(pb, enc->bit_rate); /* dwHeadBitrate */
> > @@ -344,15 +366,18 @@
> >          put_le32(pb, 0);  /* dwPTSLow */
> >          put_le32(pb, 0);  /* dwPTSHigh */
> >      } else if (enc->codec_id == CODEC_ID_GSM_MS) {
> > -        put_le16(pb, 2); /* wav_extra_size */
> > +        if (!waveformatextensible)
> > +            put_le16(pb, 2); /* wav_extra_size */
> >          hdrsize += 2;
> >          put_le16(pb, enc->frame_size); /* wSamplesPerBlock */
> >      } else if (enc->codec_id == CODEC_ID_ADPCM_IMA_WAV) {
> > -        put_le16(pb, 2); /* wav_extra_size */
> > +        if (!waveformatextensible)
> > +            put_le16(pb, 2); /* wav_extra_size */
> >          hdrsize += 2;
>
> >          put_le16(pb, enc->frame_size); /* wSamplesPerBlock */
> > -    } else if(enc->extradata_size){
> > +    } else if (enc->extradata_size){
> > -        put_le16(pb, enc->extradata_size);
> > +        if (!waveformatextensible)
> > +            put_le16(pb, enc->extradata_size);
> >          put_buffer(pb, enc->extradata, enc->extradata_size);
>
> cosmetic
>
>
> >          hdrsize += enc->extradata_size;
> >          if(hdrsize&1){
> > @@ -363,6 +388,14 @@
> >          hdrsize -= 2;
> >      }
> >
> > +    if (!url_is_streamed(pb)){
> > +        if (hdrsize > 40 && waveformatextensible) { /*  40 means 22
> WAVEFORMATEXTENSBLE size + 18 */
> > +            pos = url_ftell(pb);
> > +            url_fseek(pb, update_size_pos, SEEK_SET);
> > +            put_le16(pb, hdrsize - 18);
> > +            url_fseek(pb, pos, SEEK_SET);
> > +        }
> > +    }
>
> fails if url_is_streamed
>
>
> [...]


reference to avienc.c Line 180, write the default MAX value when
url_is_streamed  is true.
here is the new patch.

zhentan feng
-- 
Best wishes~
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