rockbox/apps/codecs/wav.c
Thom Johansen 0968536c4b Code policed. Converted to generate internal s3.28 format directly (next
task is removing use of interleaved audio). Could not test ADPCM due to
difficulty in finding files it could play, so tell me if it is broken.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@9136 a1c6a512-1295-4272-9138-f99709370657
2006-03-20 20:32:19 +00:00

716 lines
27 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 Dave Chapman
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "codeclib.h"
#include "inttypes.h"
CODEC_HEADER
/* Macro that sign extends an unsigned byte */
#define SE(x) ((int32_t)((int8_t)(x)))
struct codec_api *rb;
/* This codec support WAVE files with the following formats:
* - PCM, up to 32 bits, supporting 32 bits playback when useful.
* - ALAW and MULAW (16 bits compressed on 8 bits).
* - DVI_ADPCM (16 bits compressed on 3 or 4 bits).
*
* For a good documentation on WAVE files, see:
* http://www.tsp.ece.mcgill.ca/MMSP/Documents/AudioFormats/WAVE/WAVE.html
* and
* http://www.sonicspot.com/guide/wavefiles.html
*
* For sample WAV files, see:
* http://www.tsp.ece.mcgill.ca/MMSP/Documents/AudioFormats/WAVE/Samples.html
*
* The most common formats seem to be PCM, ADPCM, DVI_ADPCM, IEEE_FLOAT,
* ALAW and MULAW
*/
/* These constants are from RFC 2361. */
enum
{
WAVE_FORMAT_UNKNOWN = 0x0000, /* Microsoft Unknown Wave Format */
WAVE_FORMAT_PCM = 0x0001, /* Microsoft PCM Format */
WAVE_FORMAT_ADPCM = 0x0002, /* Microsoft ADPCM Format */
WAVE_FORMAT_IEEE_FLOAT = 0x0003, /* IEEE Float */
WAVE_FORMAT_VSELP = 0x0004, /* Compaq Computer's VSELP */
WAVE_FORMAT_IBM_CVSD = 0x0005, /* IBM CVSD */
WAVE_FORMAT_ALAW = 0x0006, /* Microsoft ALAW */
WAVE_FORMAT_MULAW = 0x0007, /* Microsoft MULAW */
WAVE_FORMAT_OKI_ADPCM = 0x0010, /* OKI ADPCM */
WAVE_FORMAT_DVI_ADPCM = 0x0011, /* Intel's DVI ADPCM */
WAVE_FORMAT_MEDIASPACE_ADPCM = 0x0012, /* Videologic's MediaSpace ADPCM */
WAVE_FORMAT_SIERRA_ADPCM = 0x0013, /* Sierra ADPCM */
WAVE_FORMAT_G723_ADPCM = 0x0014, /* G.723 ADPCM */
WAVE_FORMAT_DIGISTD = 0x0015, /* DSP Solutions' DIGISTD */
WAVE_FORMAT_DIGIFIX = 0x0016, /* DSP Solutions' DIGIFIX */
WAVE_FORMAT_DIALOGIC_OKI_ADPCM = 0x0017, /* Dialogic OKI ADPCM */
WAVE_FORMAT_MEDIAVISION_ADPCM = 0x0018, /* MediaVision ADPCM */
WAVE_FORMAT_CU_CODEC = 0x0019, /* HP CU */
WAVE_FORMAT_YAMAHA_ADPCM = 0x0020, /* Yamaha ADPCM */
WAVE_FORMAT_SONARC = 0x0021, /* Speech Compression's Sonarc */
WAVE_FORMAT_DSP_TRUESPEECH = 0x0022, /* DSP Group's True Speech */
WAVE_FORMAT_ECHOSC1 = 0x0023, /* Echo Speech's EchoSC1 */
WAVE_FORMAT_AUDIOFILE_AF36 = 0x0024, /* Audiofile AF36 */
WAVE_FORMAT_APTX = 0x0025, /* APTX */
WAVE_FORMAT_DOLBY_AC2 = 0x0030, /* Dolby AC2 */
WAVE_FORMAT_GSM610 = 0x0031, /* GSM610 */
WAVE_FORMAT_MSNAUDIO = 0x0032, /* MSNAudio */
WAVE_FORMAT_ANTEX_ADPCME = 0x0033, /* Antex ADPCME */
WAVE_FORMAT_MPEG = 0x0050, /* MPEG */
WAVE_FORMAT_MPEGLAYER3 = 0x0055, /* MPEG layer 3 */
WAVE_FORMAT_LUCENT_G723 = 0x0059, /* Lucent G.723 */
WAVE_FORMAT_G726_ADPCM = 0x0064, /* G.726 ADPCM */
WAVE_FORMAT_G722_ADPCM = 0x0065, /* G.722 ADPCM */
IBM_FORMAT_MULAW = 0x0101, /* same as WAVE_FORMAT_MULAW */
IBM_FORMAT_ALAW = 0x0102, /* same as WAVE_FORMAT_ALAW */
IBM_FORMAT_ADPCM = 0x0103,
WAVE_FORMAT_CREATIVE_ADPCM = 0x0200,
WAVE_FORMAT_EXTENSIBLE = 0xFFFE
};
/* Maximum number of bytes to process in one iteration */
/* for 44.1kHz stereo 16bits, this represents 0.023s ~= 1/50s */
#define WAV_CHUNK_SIZE (1024*2)
#ifdef USE_IRAM
extern char iramcopy[];
extern char iramstart[];
extern char iramend[];
extern char iedata[];
extern char iend[];
#endif
static const int16_t alaw2linear16[256] ICONST_ATTR = {
-5504, -5248, -6016, -5760, -4480, -4224, -4992,
-4736, -7552, -7296, -8064, -7808, -6528, -6272,
-7040, -6784, -2752, -2624, -3008, -2880, -2240,
-2112, -2496, -2368, -3776, -3648, -4032, -3904,
-3264, -3136, -3520, -3392, -22016, -20992, -24064,
-23040, -17920, -16896, -19968, -18944, -30208, -29184,
-32256, -31232, -26112, -25088, -28160, -27136, -11008,
-10496, -12032, -11520, -8960, -8448, -9984, -9472,
-15104, -14592, -16128, -15616, -13056, -12544, -14080,
-13568, -344, -328, -376, -360, -280, -264,
-312, -296, -472, -456, -504, -488, -408,
-392, -440, -424, -88, -72, -120, -104,
-24, -8, -56, -40, -216, -200, -248,
-232, -152, -136, -184, -168, -1376, -1312,
-1504, -1440, -1120, -1056, -1248, -1184, -1888,
-1824, -2016, -1952, -1632, -1568, -1760, -1696,
-688, -656, -752, -720, -560, -528, -624,
-592, -944, -912, -1008, -976, -816, -784,
-880, -848, 5504, 5248, 6016, 5760, 4480,
4224, 4992, 4736, 7552, 7296, 8064, 7808,
6528, 6272, 7040, 6784, 2752, 2624, 3008,
2880, 2240, 2112, 2496, 2368, 3776, 3648,
4032, 3904, 3264, 3136, 3520, 3392, 22016,
20992, 24064, 23040, 17920, 16896, 19968, 18944,
30208, 29184, 32256, 31232, 26112, 25088, 28160,
27136, 11008, 10496, 12032, 11520, 8960, 8448,
9984, 9472, 15104, 14592, 16128, 15616, 13056,
12544, 14080, 13568, 344, 328, 376, 360,
280, 264, 312, 296, 472, 456, 504,
488, 408, 392, 440, 424, 88, 72,
120, 104, 24, 8, 56, 40, 216,
200, 248, 232, 152, 136, 184, 168,
1376, 1312, 1504, 1440, 1120, 1056, 1248,
1184, 1888, 1824, 2016, 1952, 1632, 1568,
1760, 1696, 688, 656, 752, 720, 560,
528, 624, 592, 944, 912, 1008, 976,
816, 784, 880, 848
};
static const int16_t ulaw2linear16[256] ICONST_ATTR = {
-32124, -31100, -30076, -29052, -28028, -27004, -25980,
-24956, -23932, -22908, -21884, -20860, -19836, -18812,
-17788, -16764, -15996, -15484, -14972, -14460, -13948,
-13436, -12924, -12412, -11900, -11388, -10876, -10364,
-9852, -9340, -8828, -8316, -7932, -7676, -7420,
-7164, -6908, -6652, -6396, -6140, -5884, -5628,
-5372, -5116, -4860, -4604, -4348, -4092, -3900,
-3772, -3644, -3516, -3388, -3260, -3132, -3004,
-2876, -2748, -2620, -2492, -2364, -2236, -2108,
-1980, -1884, -1820, -1756, -1692, -1628, -1564,
-1500, -1436, -1372, -1308, -1244, -1180, -1116,
-1052, -988, -924, -876, -844, -812, -780,
-748, -716, -684, -652, -620, -588, -556,
-524, -492, -460, -428, -396, -372, -356,
-340, -324, -308, -292, -276, -260, -244,
-228, -212, -196, -180, -164, -148, -132,
-120, -112, -104, -96, -88, -80, -72,
-64, -56, -48, -40, -32, -24, -16,
-8, 0, 32124, 31100, 30076, 29052, 28028,
27004, 25980, 24956, 23932, 22908, 21884, 20860,
19836, 18812, 17788, 16764, 15996, 15484, 14972,
14460, 13948, 13436, 12924, 12412, 11900, 11388,
10876, 10364, 9852, 9340, 8828, 8316, 7932,
7676, 7420, 7164, 6908, 6652, 6396, 6140,
5884, 5628, 5372, 5116, 4860, 4604, 4348,
4092, 3900, 3772, 3644, 3516, 3388, 3260,
3132, 3004, 2876, 2748, 2620, 2492, 2364,
2236, 2108, 1980, 1884, 1820, 1756, 1692,
1628, 1564, 1500, 1436, 1372, 1308, 1244,
1180, 1116, 1052, 988, 924, 876, 844,
812, 780, 748, 716, 684, 652, 620,
588, 556, 524, 492, 460, 428, 396,
372, 356, 340, 324, 308, 292, 276,
260, 244, 228, 212, 196, 180, 164,
148, 132, 120, 112, 104, 96, 88,
80, 72, 64, 56, 48, 40, 32,
24, 16, 8, 0
};
static const uint16_t dvi_adpcm_steptab[89] ICONST_ATTR = {
7, 8, 9, 10, 11, 12, 13, 14,
16, 17, 19, 21, 23, 25, 28, 31,
34, 37, 41, 45, 50, 55, 60, 66,
73, 80, 88, 97, 107, 118, 130, 143,
157, 173, 190, 209, 230, 253, 279, 307,
337, 371, 408, 449, 494, 544, 598, 658,
724, 796, 876, 963, 1060, 1166, 1282, 1411,
1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024,
3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484,
7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794,
32767 };
static const int dvi_adpcm_indextab4[8] ICONST_ATTR = {
-1, -1, -1, -1, 2, 4, 6, 8 };
static const int dvi_adpcm_indextab3[4] ICONST_ATTR = { -1, -1, 1, 2 };
static int32_t samples[WAV_CHUNK_SIZE] IBSS_ATTR;
static enum codec_status
decode_dvi_adpcm(struct codec_api *ci,
const uint8_t *buf,
int n,
uint16_t channels, uint16_t bitspersample,
int32_t *pcmout,
size_t *pcmoutsize);
/* this is the codec entry point */
enum codec_status codec_start(struct codec_api *api)
{
struct codec_api *ci;
uint32_t numbytes, bytesdone;
uint32_t totalsamples = 0;
uint16_t channels = 0;
uint16_t samplesperblock = 0;
int bytespersample = 0;
uint16_t bitspersample;
uint32_t i;
size_t n, bufsize;
int endofstream;
unsigned char *buf;
uint8_t *wavbuf;
long chunksize;
uint16_t formattag = 0;
uint16_t blockalign = 0;
uint32_t avgbytespersec = 0;
off_t firstblockposn; /* position of the first block in file */
/* Generic codec initialisation */
rb = api;
ci = api;
#ifdef USE_IRAM
ci->memcpy(iramstart, iramcopy, iramend - iramstart);
ci->memset(iedata, 0, iend - iedata);
#endif
ci->configure(CODEC_DSP_ENABLE, (bool *)true);
ci->configure(DSP_SET_SAMPLE_DEPTH, (long *)28);
ci->configure(CODEC_SET_FILEBUF_WATERMARK, (int *)(1024*512));
ci->configure(CODEC_SET_FILEBUF_CHUNKSIZE, (int *)(1024*256));
ci->configure(DSP_DITHER, (bool *)false);
next_track:
if (codec_init(api)) {
i = CODEC_ERROR;
goto exit;
}
while (!*ci->taginfo_ready)
ci->yield();
/* assume the WAV header is less than 1024 bytes */
buf = ci->request_buffer((long *)&n, 1024);
if (n < 44) {
i = CODEC_ERROR;
goto exit;
}
if ((memcmp(buf, "RIFF", 4) != 0) || (memcmp(&buf[8], "WAVE", 4) != 0)) {
i = CODEC_ERROR;
goto exit;
}
buf += 12;
n -= 12;
bitspersample = 0;
numbytes = 0;
totalsamples = 0;
/* read until the data chunk, which should be last */
while (numbytes == 0 && n >= 8) {
/* chunkSize */
i = (buf[4]|(buf[5]<<8)|(buf[6]<<16)|(buf[7]<<24));
if (memcmp(buf, "fmt ", 4) == 0) {
if (i < 16) {
DEBUGF("CODEC_ERROR: 'fmt ' chunk size=%lu < 16\n", i);
i = CODEC_ERROR;
goto exit;
}
/* wFormatTag */
formattag=buf[8]|(buf[9]<<8);
/* wChannels */
channels=buf[10]|(buf[11]<<8);
/* skipping dwSamplesPerSec */
/* dwAvgBytesPerSec */
avgbytespersec = buf[16]|(buf[17]<<8)|(buf[18]<<16)|(buf[19]<<24);
/* wBlockAlign */
blockalign=buf[20]|(buf[21]<<8);
/* wBitsPerSample */
bitspersample=buf[22]|(buf[23]<<8);
if (formattag != WAVE_FORMAT_PCM) {
uint16_t size;
if (i < 18) {
/* this is not a fatal error with some formats,
* we'll see later if we can't decode it */
DEBUGF("CODEC_WARNING: non-PCM WAVE (formattag=0x%x) "
"doesn't have ext. fmt descr (chunksize=%d<18).\n",
formattag, i);
}
size = buf[24]|(buf[25]<<8);
if (formattag == WAVE_FORMAT_DVI_ADPCM) {
if (size < 2) {
DEBUGF("CODEC_ERROR: dvi_adpcm is missing "
"SamplesPerBlock value\n");
i = CODEC_ERROR;
goto exit;
}
samplesperblock = buf[26]|(buf[27]<<8);
} else if (formattag == WAVE_FORMAT_EXTENSIBLE) {
if (size < 22) {
DEBUGF("CODEC_ERROR: WAVE_FORMAT_EXTENSIBLE is "
"missing extension\n");
i = CODEC_ERROR;
goto exit;
}
/* wValidBitsPerSample */
bitspersample = buf[26]|(buf[27]<<8);
/* skipping dwChannelMask (4bytes) */
/* SubFormat (only get the first two bytes) */
formattag = buf[32]|(buf[33]<<8);
}
}
} else if (memcmp(buf, "data", 4) == 0) {
numbytes = i;
i = 0; /* advance to the beginning of data */
} else if (memcmp(buf, "fact", 4) == 0) {
/* dwSampleLength */
if (i >= 4)
totalsamples = (buf[8]|(buf[9]<<8)|(buf[10]<<16)|(buf[11]<<24));
} else {
DEBUGF("unknown WAVE chunk: '%c%c%c%c', size=%lu\n",
buf[0], buf[1], buf[2], buf[3], i);
}
/* go to next chunk (even chunk sizes must be padded) */
if (i & 0x01)
i++;
buf += i + 8;
if (n < (i + 8)) {
DEBUGF("CODEC_ERROR: WAVE header size > 1024\n");
i = CODEC_ERROR;
goto exit;
}
n -= i + 8;
}
if (channels == 0) {
DEBUGF("CODEC_ERROR: 'fmt ' chunk not found or 0-channels file\n");
i = CODEC_ERROR;
goto exit;
}
if (numbytes == 0) {
DEBUGF("CODEC_ERROR: 'data' chunk not found or has zero-length\n");
i = CODEC_ERROR;
goto exit;
}
if (formattag != WAVE_FORMAT_PCM && totalsamples == 0) {
/* This is non-fatal for some formats */
DEBUGF("CODEC_WARNING: non-PCM WAVE doesn't have a 'fact' chunk\n");
}
if (formattag == WAVE_FORMAT_ALAW || formattag == WAVE_FORMAT_MULAW ||
formattag == IBM_FORMAT_ALAW || formattag == IBM_FORMAT_MULAW) {
if (bitspersample != 8) {
DEBUGF("CODEC_ERROR: alaw and mulaw must have 8 bitspersample\n");
i = CODEC_ERROR;
goto exit;
}
bytespersample = channels;
}
if (formattag == WAVE_FORMAT_DVI_ADPCM
&& bitspersample != 4 && bitspersample != 3) {
DEBUGF("CODEC_ERROR: dvi_adpcm must have 3 or 4 bitspersample\n");
i = CODEC_ERROR;
goto exit;
}
if (formattag == WAVE_FORMAT_PCM && bitspersample > 32) {
DEBUGF("CODEC_ERROR: pcm with more than 32 bitspersample "
"is unsupported\n");
i = CODEC_ERROR;
goto exit;
}
ci->configure(DSP_SET_FREQUENCY, (long *)(ci->id3->frequency));
if (channels == 2) {
ci->configure(DSP_SET_STEREO_MODE, (long *)STEREO_INTERLEAVED);
} else if (channels == 1) {
ci->configure(DSP_SET_STEREO_MODE, (long *)STEREO_MONO);
} else {
DEBUGF("CODEC_ERROR: more than 2 channels\n");
i = CODEC_ERROR;
goto exit;
}
if (totalsamples == 0) {
if (formattag == WAVE_FORMAT_PCM ||
formattag == WAVE_FORMAT_ALAW || formattag == WAVE_FORMAT_MULAW ||
formattag == IBM_FORMAT_ALAW || formattag == IBM_FORMAT_MULAW) {
/* for PCM and derived formats only */
bytespersample = (((bitspersample - 1)/8 + 1)*channels);
totalsamples = numbytes/bytespersample;
} else {
DEBUGF("CODEC_ERROR: cannot compute totalsamples\n");
i = CODEC_ERROR;
goto exit;
}
}
firstblockposn = 1024 - n;
ci->advance_buffer(firstblockposn);
/* The main decoder loop */
bytesdone = 0;
ci->set_elapsed(0);
endofstream = 0;
/* chunksize is computed so that one chunk is about 1/50s.
* this make 4096 for 44.1kHz 16bits stereo.
* It also has to be a multiple of blockalign */
chunksize = (1 + avgbytespersec / (50*blockalign))*blockalign;
/* check that the output buffer is big enough (convert to samplespersec,
then round to the blockalign multiple below) */
if (((uint64_t)chunksize*ci->id3->frequency*channels*sizeof(long))
/(uint64_t)avgbytespersec >= WAV_CHUNK_SIZE) {
chunksize = ((uint64_t)WAV_CHUNK_SIZE*avgbytespersec
/((uint64_t)ci->id3->frequency*channels*sizeof(long)
*blockalign))*blockalign;
}
while (!endofstream) {
ci->yield();
if (ci->stop_codec || ci->reload_codec) {
break;
}
if (ci->seek_time) {
uint32_t newpos;
/* use avgbytespersec to round to the closest blockalign multiple,
add firstblockposn. 64-bit casts to avoid overflows. */
newpos = (((uint64_t)avgbytespersec*(ci->seek_time - 1))
/ (1000LL*blockalign))*blockalign;
if (newpos > numbytes)
break;
if (ci->seek_buffer(firstblockposn + newpos))
bytesdone = newpos;
ci->seek_complete();
}
wavbuf = (uint8_t *)ci->request_buffer((long *)&n, chunksize);
if (n == 0)
break; /* End of stream */
if (bytesdone + n > numbytes) {
n = numbytes - bytesdone;
endofstream = 1;
}
if (formattag == WAVE_FORMAT_PCM) {
if (bitspersample > 24) {
for (i = 0; i < n; i += 4) {
samples[i/4] = (wavbuf[i] >> 3)|
(wavbuf[i + 1]<<5)|(wavbuf[i + 2]<<13)|
(SE(wavbuf[i + 3])<<21);
}
bufsize = n;
} else if (bitspersample > 16) {
for (i = 0; i < n; i += 3) {
samples[i/3] = (wavbuf[i]<<5)|
(wavbuf[i + 1]<<13)|(SE(wavbuf[i + 2])<<21);
}
bufsize = n*4/3;
} else if (bitspersample > 8) {
for (i = 0; i < n; i += 2) {
samples[i/2] = (wavbuf[i]<<13)|(SE(wavbuf[i + 1])<<21);
}
bufsize = n*2;
} else {
for (i = 0; i < n; i++) {
samples[i] = (wavbuf[i] - 0x80)<<21;
}
bufsize = n*4;
}
} else if (formattag == WAVE_FORMAT_ALAW
|| formattag == IBM_FORMAT_ALAW) {
for (i = 0; i < n; i++)
samples[i] = alaw2linear16[wavbuf[i]] << 13;
bufsize = n*4;
} else if (formattag == WAVE_FORMAT_MULAW
|| formattag == IBM_FORMAT_MULAW) {
for (i = 0; i < n; i++)
samples[i] = ulaw2linear16[wavbuf[i]] << 13;
bufsize = n*4;
}
else if (formattag == WAVE_FORMAT_DVI_ADPCM) {
unsigned int nblocks = chunksize/blockalign;
for (i = 0; i < nblocks; i++) {
size_t decodedsize = samplesperblock*channels;
if (decode_dvi_adpcm(ci, ((uint8_t *)wavbuf) + i*blockalign,
blockalign, channels, bitspersample,
samples + i*samplesperblock*channels,
&decodedsize) != CODEC_OK)
i = CODEC_ERROR;
goto exit;
}
bufsize = nblocks*samplesperblock*channels*2;
} else {
DEBUGF("CODEC_ERROR: unsupported format %x\n", formattag);
i = CODEC_ERROR;
goto exit;
}
while (!ci->pcmbuf_insert((char *)samples, bufsize))
ci->yield();
ci->advance_buffer(n);
bytesdone += n;
if (bytesdone >= numbytes)
endofstream = 1;
ci->set_elapsed(bytesdone*1000LL/avgbytespersec);
}
if (ci->request_next_track())
goto next_track;
i = CODEC_OK;
exit:
return i;
}
static enum codec_status
decode_dvi_adpcm(struct codec_api *ci,
const uint8_t *buf,
int n,
uint16_t channels, uint16_t bitspersample,
int32_t *pcmout,
size_t *pcmoutsize)
{
size_t nsamples = 0;
int sample[2];
int samplecode[32][2];
int i;
int stepindex[2];
int c;
int diff;
int step;
int codem;
int code;
(void)ci;
if (bitspersample != 4 && bitspersample != 3) {
DEBUGF("decode_dvi_adpcm: wrong bitspersample\n");
return CODEC_ERROR;
}
/* decode block header */
for (c = 0; c < channels && n >= 4; c++) {
/* decode + push first sample */
sample[c] = (short)(buf[0]|(buf[1]<<8));/* need cast for sign-extend */
pcmout[c] = sample[c];
nsamples++;
stepindex[c] = buf[2];
/* check for step table index overflow */
if (stepindex[c] > 88) {
DEBUGF("decode_dvi_adpcm: stepindex[%d]=%d>88\n",c,stepindex[c]);
return CODEC_ERROR;
}
buf += 4;
n -= 4;
}
if (bitspersample == 4) {
while (n>= channels*4 && (nsamples + 8*channels) <= *pcmoutsize) {
for (c = 0; c < channels; c++) {
samplecode[0][c] = buf[0]&0xf;
samplecode[1][c] = buf[0]>>4;
samplecode[2][c] = buf[1]&0xf;
samplecode[3][c] = buf[1]>>4;
samplecode[4][c] = buf[2]&0xf;
samplecode[5][c] = buf[2]>>4;
samplecode[6][c] = buf[3]&0xf;
samplecode[7][c] = buf[3]>>4;
buf += 4;
n -= 4;
}
for (i = 0; i < 8; i++) {
for (c = 0; c < channels; c++) {
step = dvi_adpcm_steptab[stepindex[c]];
codem = samplecode[i][c];
code = codem & 0x07;
/* adjust the step table index */
stepindex[c] += dvi_adpcm_indextab4[code];
/* check for step table index overflow and underflow */
if (stepindex[c] > 88)
stepindex[c] = 88;
else if (stepindex[c] < 0)
stepindex[c] = 0;
/* calculate the difference */
#ifdef STRICT_IMA
diff = 0;
if (code & 4)
diff += step;
step = step >> 1;
if (code & 2)
diff += step;
step = step >> 1;
if (code & 1)
diff += step;
step = step >> 1;
diff += step;
#else
diff = ((code + code + 1) * step) >> 3; /* faster */
#endif
/* check the sign bit */
/* check for overflow and underflow errors */
if (code != codem) {
sample[c] -= diff;
if (sample[c] < -32768)
sample[c] = -32768;
} else {
sample[c] += diff;
if (sample[c] > 32767)
sample[c] = 32767;
}
/* output the new sample */
pcmout[nsamples] = sample[c] << 13;
nsamples++;
}
}
}
} else { /* bitspersample == 3 */
while (n >= channels*12 && (nsamples + 32*channels) <= *pcmoutsize) {
for (c = 0; c < channels; c++) {
uint16_t bitstream = 0;
int bitsread = 0;
for (i = 0; i < 32 && n > 0; i++) {
if (bitsread < 3) {
/* read 8 more bits */
bitstream |= buf[0]<<bitsread;
bitsread += 8;
n--;
buf++;
}
samplecode[i][c] = bitstream & 7;
bitstream = bitstream>>3;
bitsread -= 3;
}
if (bitsread != 0) {
/* 32*3 = 3 words, so we should end with bitsread==0 */
DEBUGF("decode_dvi_adpcm: error in implementation\n");
return CODEC_ERROR;
}
}
for (i = 0; i < 32; i++) {
for (c = 0; c < channels; c++) {
step = dvi_adpcm_steptab[stepindex[c]];
codem = samplecode[i][c];
code = codem & 0x03;
/* adjust the step table index */
stepindex[c] += dvi_adpcm_indextab3[code];
/* check for step table index overflow and underflow */
if (stepindex[c] > 88)
stepindex[c] = 88;
else if (stepindex[c] < 0)
stepindex[c] = 0;
/* calculate the difference */
#ifdef STRICT_IMA
diff = 0;
if (code & 2)
diff += step;
step = step >> 1;
if (code & 1)
diff += step;
step = step >> 1;
diff += step;
#else
diff = ((code + code + 1) * step) >> 3; /* faster */
#endif
/* check the sign bit */
/* check for overflow and underflow errors */
if (code != codem) {
sample[c] -= diff;
if (sample[c] < -32768)
sample[c] = -32768;
}
else {
sample[c] += diff;
if (sample[c] > 32767)
sample[c] = 32767;
}
/* output the new sample */
pcmout[nsamples] = sample[c] << 13;
nsamples++;
}
}
}
}
if (nsamples > *pcmoutsize) {
DEBUGF("decode_dvi_adpcm: output buffer overflow!\n");
return CODEC_ERROR;
}
*pcmoutsize = nsamples;
if (n != 0) {
DEBUGF("decode_dvi_adpcm: n=%d unprocessed bytes\n", n);
}
return CODEC_OK;
}