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adpcm encoding patch by François Revol <revol at free dot fr>

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Originally committed as revision 785 to svn://svn.ffmpeg.org/ffmpeg/trunk
pull/126/head
François Revol 23 years ago committed by Michael Niedermayer
parent 27a5e8b897
commit 889c522492
2 changed files with 144 additions and 15 deletions
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  1. 5
      libav/wav.c
  2. 154
      libavcodec/adpcm.c

5
libav/wav.c
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@ -51,6 +51,8 @@ int put_wav_header(ByteIOContext *pb, AVCodecContext *enc)
bps = 8;
} else if (enc->codec_id == CODEC_ID_MP2 || enc->codec_id == CODEC_ID_MP3LAME) {
bps = 0;
} else if (enc->codec_id == CODEC_ID_ADPCM_IMA_WAV || enc->codec_id == CODEC_ID_ADPCM_MS) {
bps = 4;
} else {
bps = 16;
}
@ -90,6 +92,9 @@ int put_wav_header(ByteIOContext *pb, AVCodecContext *enc)
put_le16(pb, 16); /* fwHeadFlags */
put_le32(pb, 0); /* dwPTSLow */
put_le32(pb, 0); /* dwPTSHigh */
} else if (enc->codec_id == CODEC_ID_ADPCM_IMA_WAV) {
put_le16(pb, 2); /* wav_extra_size */
put_le16(pb, ((enc->block_align - 4 * enc->channels) / (4 * enc->channels)) * 8 + 1); /* wSamplesPerBlock */
} else
put_le16(pb, 0); /* wav_extra_size */

154
libavcodec/adpcm.c
Unescape View File

@ -28,6 +28,8 @@
* 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
@ -60,6 +62,7 @@ static int step_table[89] = {
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,
@ -80,6 +83,8 @@ typedef struct ADPCMChannelStatus {
int predictor;
short int step_index;
int step;
/* for encoding */
int prev_sample;
/* MS version */
short sample1;
@ -99,15 +104,26 @@ typedef struct ADPCMContext {
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:
avctx->frame_size = 64; /* XXX: ??? */
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 = 64; /* XXX: ??? */
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:
avctx->frame_size = 1;
return -1;
break;
}
return 0;
@ -115,28 +131,129 @@ static int adpcm_encode_init(AVCodecContext *avctx)
static int adpcm_encode_close(AVCodecContext *avctx)
{
switch(avctx->codec->id) {
default:
/* nothing to free */
break;
}
/* nothing to free */
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, sample_size, v;
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;
}
avctx->key_frame = 1;
//avctx->frame_size = (dst - frame) / (sample_size * avctx->channels);
return dst - frame;
}
@ -221,8 +338,6 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
samples = data;
src = buf;
//printf("adpcm_decode_frame() buf_size=%i\n", buf_size);
st = avctx->channels == 2;
switch(avctx->codec->id) {
@ -245,7 +360,7 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
cs->step_index = (*src++) & 0x7F;
if (cs->step_index > 88) printf("ERROR: step_index = %i\n", cs->step_index);
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];
@ -253,6 +368,9 @@ if (cs->step_index > 88) printf("ERROR: step_index = %i\n", 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;
@ -284,10 +402,13 @@ if (cs->step_index > 88) printf("ERROR: step_index = %i\n", cs->step_index);
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++) puts("unused byte should be null !!"); /* unused */
if (*src++) fprintf(stderr, "unused byte should be null !!\n"); /* unused */
if (st) {
cs = &(c->status[1]);
cs->predictor = (*src++) & 0x0FF;
@ -296,6 +417,8 @@ if (cs->step_index > 88) printf("ERROR: step_index = %i\n", cs->step_index);
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;
@ -404,3 +527,4 @@ ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);
ADPCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);
#undef ADPCM_CODEC

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