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wav: Add R/W support for MPEG_LAYER_III subformat in wav

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This commit is contained in:
Arthur Taylor 2021-03-25 16:01:08 -07:00
parent c42e41324b
commit 4b8209e650
2 changed files with 63 additions and 3 deletions
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2
src/sndfile.c
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@ -691,6 +691,8 @@ sf_format_check (const SF_INFO *info)
if ((subformat == SF_FORMAT_NMS_ADPCM_16 || subformat == SF_FORMAT_NMS_ADPCM_24 ||
subformat == SF_FORMAT_NMS_ADPCM_32) && info->channels == 1)
return 1 ;
if (subformat == SF_FORMAT_MPEG_LAYER_III && info->channels <= 2)
return 1 ;
break ;
case SF_FORMAT_WAVEX :

64
src/wav.c
View File

@ -91,7 +91,6 @@ enum
} ;
/* known WAVEFORMATEXTENSIBLE GUIDS */
static const EXT_SUBFORMAT MSGUID_SUBTYPE_PCM =
{ 0x00000001, 0x0000, 0x0010, { 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 }
@ -278,6 +277,10 @@ wav_open (SF_PRIVATE *psf)
error = gsm610_init (psf) ;
break ;
case SF_FORMAT_MPEG_LAYER_III :
error = mpeg_init (psf, SF_BITRATE_MODE_CONSTANT, SF_FALSE) ;
break ;
default : return SFE_UNIMPLEMENTED ;
} ;
@ -696,8 +699,6 @@ wav_read_header (SF_PRIVATE *psf, int *blockalign, int *framesperblock)
break ;
case WAVE_FORMAT_NMS_VBXADPCM :
*blockalign = wav_fmt->min.blockalign ;
*framesperblock = 160 ;
switch (wav_fmt->min.bitwidth)
{ case 2 :
psf->sf.format = SF_FORMAT_WAV | SF_FORMAT_NMS_ADPCM_16 ;
@ -753,6 +754,12 @@ wav_read_header (SF_PRIVATE *psf, int *blockalign, int *framesperblock)
psf->sf.format = SF_FORMAT_WAV | SF_FORMAT_G721_32 ;
break ;
case WAVE_FORMAT_MPEGLAYER3 :
psf->sf.format = SF_FORMAT_WAV | SF_FORMAT_MPEG_LAYER_III ;
if (parsestage & HAVE_fact)
psf->sf.frames = fact_chunk.frames ;
break ;
default : return SFE_UNIMPLEMENTED ;
} ;
@ -937,6 +944,57 @@ wav_write_fmt_chunk (SF_PRIVATE *psf)
add_fact_chunk = SF_TRUE ;
break ;
case SF_FORMAT_MPEG_LAYER_III :
{ int bytespersec, blockalign, flags, blocksize, samplesperblock, codecdelay ;
/* Intended to be set as the average sample rate.
** TODO: Maybe re-write this on close with final average
** byterate? */
bytespersec = psf->byterate (psf) ;
/* Average block size. Info only I think. */
blocksize = (1152 * bytespersec) / psf->sf.samplerate ;
/* Can be set to block size IFF the block size is
** constant, set to 1 otherwise. Constant sized
** MPEG block streams are uncommon (CBR @ 32kHz and
** 48kHz only. Meh. */
blockalign = 1 ;
/* TODO: Only flags defined are padding-type. I /think/
** Lame does ISO style padding by default, which has a
** flag value of 0.
*/
flags = 0 ;
/* Should only vary per MPEG 1.0/2.0 vs '2.5'.
** TODO: Move this out to MPEG specific place? */
samplesperblock = psf->sf.samplerate >= 32000 ? 1152 : 576 ;
/* Set as 0 if unknown.
** TODO: Plumb this cleanly from Lame.
*/
codecdelay = 0 ;
/* fmt chunk. */
fmt_size = 2 + 2 + 4 + 4 + 2 + 2 + 2 + 2 + 4 + 2 + 2 + 2 ;
/* fmt : size, WAV format type, channels. */
psf_binheader_writef (psf, "422", BHW4 (fmt_size), BHW2 (WAVE_FORMAT_MPEGLAYER3), BHW2 (psf->sf.channels)) ;
/* fmt : samplerate, bytespersec. */
psf_binheader_writef (psf, "44", BHW4 (psf->sf.samplerate), BHW4 (bytespersec)) ;
/* fmt : blockalign, bitwidth, extrabytes, id. */
psf_binheader_writef (psf, "2222", BHW2 (blockalign), BHW2 (0), BHW2 (12), BHW2 (1)) ;
/* fmt : flags, blocksize, samplesperblock, codecdelay */
psf_binheader_writef (psf, "4222", BHW4 (flags), BHW2 (blocksize), BHW2 (samplesperblock), BHW2 (codecdelay)) ;
} ;
add_fact_chunk = SF_TRUE ;
break ;
default : return SFE_UNIMPLEMENTED ;
} ;