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FFmpeg/libavcodec/adpcm.c

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/*
* ADPCM codecs
* Copyright (c) 2001 Fabrice Bellard.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "avcodec.h"
/*
* First version by Francois Revol revol@free.fr
*
* Features and limitations:
*
* Reference documents:
* http://www.pcisys.net/~melanson/codecs/adpcm.txt
* http://www.geocities.com/SiliconValley/8682/aud3.txt
* http://openquicktime.sourceforge.net/plugins.htm
* XAnim sources (xa_codec.c) http://www.rasnaimaging.com/people/lapus/download.html
* http://www.cs.ucla.edu/~leec/mediabench/applications.html
* SoX source code http://home.sprynet.com/~cbagwell/sox.html
*/
#define BLKSIZE 1024
#define CLAMP_TO_SHORT(value) \
if (value > 32767) \
value = 32767; \
else if (value < -32768) \
value = -32768; \
/* step_table[] and index_table[] are from the ADPCM reference source */
/* This is the index table: */
static int index_table[16] = {
-1, -1, -1, -1, 2, 4, 6, 8,
-1, -1, -1, -1, 2, 4, 6, 8,
};
/* This is the step table. Note that many programs use slight deviations from
* this table, but such deviations are negligible:
*/
static int step_table[89] = {
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
};
/* Those are for MS-ADPCM */
/* AdaptationTable[], AdaptCoeff1[], and AdaptCoeff2[] are from libsndfile */
static int AdaptationTable[] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
};
static int AdaptCoeff1[] = {
256, 512, 0, 192, 240, 460, 392
};
static int AdaptCoeff2[] = {
0, -256, 0, 64, 0, -208, -232
};
/* end of tables */
typedef struct ADPCMChannelStatus {
int predictor;
short int step_index;
int step;
/* for encoding */
int prev_sample;
/* MS version */
short sample1;
short sample2;
int coeff1;
int coeff2;
int idelta;
} ADPCMChannelStatus;
typedef struct ADPCMContext {
int channel; /* for stereo MOVs, decode left, then decode right, then tell it's decoded */
ADPCMChannelStatus status[2];
short sample_buffer[32]; /* hold left samples while waiting for right samples */
} ADPCMContext;
/* XXX: implement encoding */
static int adpcm_encode_init(AVCodecContext *avctx)
{
if (avctx->channels > 2)
return -1; /* only stereo or mono =) */
switch(avctx->codec->id) {
case CODEC_ID_ADPCM_IMA_QT:
fprintf(stderr, "ADPCM: codec admcp_ima_qt unsupported for encoding !\n");
avctx->frame_size = 64; /* XXX: can multiple of avctx->channels * 64 (left and right blocks are interleaved) */
return -1;
break;
case CODEC_ID_ADPCM_IMA_WAV:
avctx->frame_size = (BLKSIZE - 4 * avctx->channels) * 8 / (4 * avctx->channels) + 1; /* each 16 bits sample gives one nibble */
/* and we have 4 bytes per channel overhead */
avctx->block_align = BLKSIZE;
/* seems frame_size isn't taken into account... have to buffer the samples :-( */
break;
case CODEC_ID_ADPCM_MS:
fprintf(stderr, "ADPCM: codec admcp_ms unsupported for encoding !\n");
return -1;
break;
default:
return -1;
break;
}
avctx->coded_frame= avcodec_alloc_frame();
avctx->coded_frame->key_frame= 1;
return 0;
}
static int adpcm_encode_close(AVCodecContext *avctx)
{
av_freep(&avctx->coded_frame);
return 0;
}
static inline unsigned char adpcm_ima_compress_sample(ADPCMChannelStatus *c, short sample)
{
int step_index;
unsigned char nibble;
int sign = 0; /* sign bit of the nibble (MSB) */
int delta, predicted_delta;
delta = sample - c->prev_sample;
if (delta < 0) {
sign = 1;
delta = -delta;
}
step_index = c->step_index;
/* nibble = 4 * delta / step_table[step_index]; */
nibble = (delta << 2) / step_table[step_index];
if (nibble > 7)
nibble = 7;
step_index += index_table[nibble];
if (step_index < 0)
step_index = 0;
if (step_index > 88)
step_index = 88;
/* what the decoder will find */
predicted_delta = ((step_table[step_index] * nibble) / 4) + (step_table[step_index] / 8);
if (sign)
c->prev_sample -= predicted_delta;
else
c->prev_sample += predicted_delta;
CLAMP_TO_SHORT(c->prev_sample);
nibble += sign << 3; /* sign * 8 */
/* save back */
c->step_index = step_index;
return nibble;
}
static int adpcm_encode_frame(AVCodecContext *avctx,
unsigned char *frame, int buf_size, void *data)
{
int n;
short *samples;
unsigned char *dst;
ADPCMContext *c = avctx->priv_data;
dst = frame;
samples = (short *)data;
/* n = (BLKSIZE - 4 * avctx->channels) / (2 * 8 * avctx->channels); */
switch(avctx->codec->id) {
case CODEC_ID_ADPCM_IMA_QT: /* XXX: can't test until we get .mov writer */
break;
case CODEC_ID_ADPCM_IMA_WAV:
n = avctx->frame_size / 8;
c->status[0].prev_sample = (signed short)samples[0]; /* XXX */
/* c->status[0].step_index = 0; *//* XXX: not sure how to init the state machine */
*dst++ = (c->status[0].prev_sample) & 0xFF; /* little endian */
*dst++ = (c->status[0].prev_sample >> 8) & 0xFF;
*dst++ = (unsigned char)c->status[0].step_index;
*dst++ = 0; /* unknown */
samples++;
if (avctx->channels == 2) {
c->status[1].prev_sample = (signed short)samples[0];
/* c->status[1].step_index = 0; */
*dst++ = (c->status[1].prev_sample) & 0xFF;
*dst++ = (c->status[1].prev_sample >> 8) & 0xFF;
*dst++ = (unsigned char)c->status[1].step_index;
*dst++ = 0;
samples++;
}
/* stereo: 4 bytes (8 samples) for left, 4 bytes for right, 4 bytes left, ... */
for (; n>0; n--) {
*dst = adpcm_ima_compress_sample(&c->status[0], samples[0]) & 0x0F;
*dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels]) << 4) & 0xF0;
dst++;
*dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 2]) & 0x0F;
*dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 3]) << 4) & 0xF0;
dst++;
*dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 4]) & 0x0F;
*dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 5]) << 4) & 0xF0;
dst++;
*dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 6]) & 0x0F;
*dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 7]) << 4) & 0xF0;
dst++;
/* right channel */
if (avctx->channels == 2) {
*dst = adpcm_ima_compress_sample(&c->status[1], samples[1]);
*dst |= adpcm_ima_compress_sample(&c->status[1], samples[3]) << 4;
dst++;
*dst = adpcm_ima_compress_sample(&c->status[1], samples[5]);
*dst |= adpcm_ima_compress_sample(&c->status[1], samples[7]) << 4;
dst++;
*dst = adpcm_ima_compress_sample(&c->status[1], samples[9]);
*dst |= adpcm_ima_compress_sample(&c->status[1], samples[11]) << 4;
dst++;
*dst = adpcm_ima_compress_sample(&c->status[1], samples[13]);
*dst |= adpcm_ima_compress_sample(&c->status[1], samples[15]) << 4;
dst++;
}
samples += 8 * avctx->channels;
}
break;
default:
return -1;
}
return dst - frame;
}
static int adpcm_decode_init(AVCodecContext * avctx)
{
ADPCMContext *c = avctx->priv_data;
c->channel = 0;
c->status[0].predictor = c->status[1].predictor = 0;
c->status[0].step_index = c->status[1].step_index = 0;
c->status[0].step = c->status[1].step = 0;
switch(avctx->codec->id) {
default:
break;
}
return 0;
}
static inline short adpcm_ima_expand_nibble(ADPCMChannelStatus *c, char nibble)
{
int step_index;
int predictor;
int sign, delta, diff, step;
predictor = c->predictor;
step_index = c->step_index + index_table[(unsigned)nibble];
if (step_index < 0) step_index = 0;
if (step_index > 88) step_index = 88;
step = c->step;
/*
diff = ((signed)((nibble & 0x08)?(nibble | 0xF0):(nibble)) + 0.5) * step / 4;
predictor += diff;
*/
sign = nibble & 8;
delta = nibble & 7;
diff = step >> 3;
if (delta & 4) diff += step;
if (delta & 2) diff += step >> 1;
if (delta & 1) diff += step >> 2;
if (sign) predictor -= diff;
else predictor += diff;
CLAMP_TO_SHORT(predictor);
c->predictor = predictor;
c->step_index = step_index;
c->step = step_table[step_index];
return (short)predictor;
}
static inline short adpcm_ms_expand_nibble(ADPCMChannelStatus *c, char nibble)
{
int predictor;
predictor = (((c->sample1) * (c->coeff1)) + ((c->sample2) * (c->coeff2))) / 256;
predictor += (signed)((nibble & 0x08)?(nibble - 0x10):(nibble)) * c->idelta;
CLAMP_TO_SHORT(predictor);
c->sample2 = c->sample1;
c->sample1 = predictor;
c->idelta = (AdaptationTable[(int)nibble] * c->idelta) / 256;
if (c->idelta < 16) c->idelta = 16;
return (short)predictor;
}
static int adpcm_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
ADPCMContext *c = avctx->priv_data;
ADPCMChannelStatus *cs;
int n, m, channel;
int block_predictor[2];
short *samples;
uint8_t *src;
int st; /* stereo */
samples = data;
src = buf;
st = avctx->channels == 2;
switch(avctx->codec->id) {
case CODEC_ID_ADPCM_IMA_QT:
n = (buf_size - 2);/* >> 2*avctx->channels;*/
channel = c->channel;
cs = &(c->status[channel]);
/* (pppppp) (piiiiiii) */
/* Bits 15-7 are the _top_ 9 bits of the 16-bit initial predictor value */
cs->predictor = (*src++) << 8;
cs->predictor |= (*src & 0x80);
cs->predictor &= 0xFF80;
/* sign extension */
if(cs->predictor & 0x8000)
cs->predictor -= 0x10000;
CLAMP_TO_SHORT(cs->predictor);
cs->step_index = (*src++) & 0x7F;
if (cs->step_index > 88) fprintf(stderr, "ERROR: step_index = %i\n", cs->step_index);
if (cs->step_index > 88) cs->step_index = 88;
cs->step = step_table[cs->step_index];
if (st && channel)
samples++;
*samples++ = cs->predictor;
samples += st;
for(m=32; n>0 && m>0; n--, m--) { /* in QuickTime, IMA is encoded by chuncks of 34 bytes (=64 samples) */
*samples = adpcm_ima_expand_nibble(cs, src[0] & 0x0F);
samples += avctx->channels;
*samples = adpcm_ima_expand_nibble(cs, (src[0] >> 4) & 0x0F);
samples += avctx->channels;
src ++;
}
if(st) { /* handle stereo interlacing */
c->channel = (channel + 1) % 2; /* we get one packet for left, then one for right data */
if(channel == 0) { /* wait for the other packet before outputing anything */
*data_size = 0;
return src - buf;
}
}
break;
case CODEC_ID_ADPCM_IMA_WAV:
if (buf_size > BLKSIZE) {
if (avctx->block_align != 0)
buf_size = avctx->block_align;
else
buf_size = BLKSIZE;
}
n = buf_size - 4 * avctx->channels;
cs = &(c->status[0]);
cs->predictor = (*src++) & 0x0FF;
cs->predictor |= ((*src++) << 8) & 0x0FF00;
if(cs->predictor & 0x8000)
cs->predictor -= 0x10000;
CLAMP_TO_SHORT(cs->predictor);
*samples++ = cs->predictor;
cs->step_index = *src++;
if (cs->step_index < 0) cs->step_index = 0;
if (cs->step_index > 88) cs->step_index = 88;
if (*src++) fprintf(stderr, "unused byte should be null !!\n"); /* unused */
if (st) {
cs = &(c->status[1]);
cs->predictor = (*src++) & 0x0FF;
cs->predictor |= ((*src++) << 8) & 0x0FF00;
if(cs->predictor & 0x8000)
cs->predictor -= 0x10000;
CLAMP_TO_SHORT(cs->predictor);
*samples++ = cs->predictor;
cs->step_index = *src++;
if (cs->step_index < 0) cs->step_index = 0;
if (cs->step_index > 88) cs->step_index = 88;
src++; /* unused */
}
cs = &(c->status[0]);
for(m=3; n>0; n--, m--) {
*samples++ = adpcm_ima_expand_nibble(&c->status[0], src[0] & 0x0F);
if (st)
*samples++ = adpcm_ima_expand_nibble(&c->status[1], src[4] & 0x0F);
*samples++ = adpcm_ima_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);
if (st)
*samples++ = adpcm_ima_expand_nibble(&c->status[1], (src[4] >> 4) & 0x0F);
src ++;
if (st && !m) {
m=3;
src+=4;
}
}
break;
case CODEC_ID_ADPCM_MS:
if (buf_size > BLKSIZE) {
if (avctx->block_align != 0)
buf_size = avctx->block_align;
else
buf_size = BLKSIZE;
}
n = buf_size - 7 * avctx->channels;
if (n < 0)
return -1;
block_predictor[0] = (*src++); /* should be bound */
block_predictor[0] = (block_predictor[0] < 0)?(0):((block_predictor[0] > 7)?(7):(block_predictor[0]));
block_predictor[1] = 0;
if (st)
block_predictor[1] = (*src++);
block_predictor[1] = (block_predictor[1] < 0)?(0):((block_predictor[1] > 7)?(7):(block_predictor[1]));
c->status[0].idelta = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
if (c->status[0].idelta & 0x08000)
c->status[0].idelta -= 0x10000;
src+=2;
if (st)
c->status[1].idelta = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
if (st && c->status[1].idelta & 0x08000)
c->status[1].idelta |= 0xFFFF0000;
if (st)
src+=2;
c->status[0].coeff1 = AdaptCoeff1[block_predictor[0]];
c->status[0].coeff2 = AdaptCoeff2[block_predictor[0]];
c->status[1].coeff1 = AdaptCoeff1[block_predictor[1]];
c->status[1].coeff2 = AdaptCoeff2[block_predictor[1]];
c->status[0].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
src+=2;
if (st) c->status[1].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
if (st) src+=2;
c->status[0].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
src+=2;
if (st) c->status[1].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
if (st) src+=2;
*samples++ = c->status[0].sample1;
if (st) *samples++ = c->status[1].sample1;
*samples++ = c->status[0].sample2;
if (st) *samples++ = c->status[1].sample2;
for(;n>0;n--) {
*samples++ = adpcm_ms_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);
*samples++ = adpcm_ms_expand_nibble(&c->status[st], src[0] & 0x0F);
src ++;
}
break;
default:
*data_size = 0;
return -1;
}
*data_size = (uint8_t *)samples - (uint8_t *)data;
return src - buf;
}
#define ADPCM_CODEC(id, name) \
AVCodec name ## _encoder = { \
#name, \
CODEC_TYPE_AUDIO, \
id, \
sizeof(ADPCMContext), \
adpcm_encode_init, \
adpcm_encode_frame, \
adpcm_encode_close, \
NULL, \
}; \
AVCodec name ## _decoder = { \
#name, \
CODEC_TYPE_AUDIO, \
id, \
sizeof(ADPCMContext), \
adpcm_decode_init, \
NULL, \
NULL, \
adpcm_decode_frame, \
};
ADPCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);
ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);
ADPCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);
#undef ADPCM_CODEC