generic-library/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Add Yamaha ADPCM encoding/decoding patch by (Vidar Madsen: vidarino, gmail com)

Browse Source 
Originally committed as revision 4442 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Vidar Madsen 2005-07-15 06:51:36 +00:00 committed by Michael Niedermayer
parent e0111b3243
commit 2ff4524e72
3 changed files with 85 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

82
libavcodec/adpcm.c
View File

@ -117,6 +117,16 @@ static const int swf_index_tables[4][16] = {
/*5*/ { -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 4, 6, 8, 10, 13, 16 }
};
static const int yamaha_indexscale[] = {
230, 230, 230, 230, 307, 409, 512, 614,
230, 230, 230, 230, 307, 409, 512, 614
};
static const int yamaha_difflookup[] = {
1, 3, 5, 7, 9, 11, 13, 15,
-1, -3, -5, -7, -9, -11, -13, -15
};
/* end of tables */
typedef struct ADPCMChannelStatus {
@ -168,6 +178,10 @@ static int adpcm_encode_init(AVCodecContext *avctx)
/* and we have 7 bytes per channel overhead */
avctx->block_align = BLKSIZE;
break;
case CODEC_ID_ADPCM_YAMAHA:
avctx->frame_size = BLKSIZE * avctx->channels;
avctx->block_align = BLKSIZE;
break;
default:
return -1;
break;
@ -260,6 +274,31 @@ static inline unsigned char adpcm_ms_compress_sample(ADPCMChannelStatus *c, shor
return nibble;
}
static inline unsigned char adpcm_yamaha_compress_sample(ADPCMChannelStatus *c, short sample)
{
int i1 = 0, j1;
if(!c->step) {
c->predictor = 0;
c->step = 127;
}
j1 = sample - c->predictor;
j1 = (j1 * 8) / c->step;
i1 = abs(j1) / 2;
if (i1 > 7)
i1 = 7;
if (j1 < 0)
i1 += 8;
c->predictor = c->predictor + ((c->step * yamaha_difflookup[i1]) / 8);
CLAMP_TO_SHORT(c->predictor);
c->step = (c->step * yamaha_indexscale[i1]) >> 8;
c->step = clip(c->step, 127, 24567);
return i1;
}
static int adpcm_encode_frame(AVCodecContext *avctx,
unsigned char *frame, int buf_size, void *data)
{
@ -362,6 +401,18 @@ static int adpcm_encode_frame(AVCodecContext *avctx,
*dst++ = nibble;
}
break;
case CODEC_ID_ADPCM_YAMAHA:
n = avctx->frame_size / 2;
for (; n>0; n--) {
for(i = 0; i < avctx->channels; i++) {
int nibble;
nibble = adpcm_yamaha_compress_sample(&c->status[i], samples[i]) << 4;
nibble |= adpcm_yamaha_compress_sample(&c->status[i], samples[i+avctx->channels]);
*dst++ = nibble;
}
samples += 2 * avctx->channels;
}
break;
default:
return -1;
}
@ -463,6 +514,20 @@ static inline short adpcm_ct_expand_nibble(ADPCMChannelStatus *c, char nibble)
return (short)predictor;
}
static inline short adpcm_yamaha_expand_nibble(ADPCMChannelStatus *c, unsigned char nibble)
{
if(!c->step) {
c->predictor = 0;
c->step = 127;
}
c->predictor += (c->step * yamaha_difflookup[nibble]) / 8;
CLAMP_TO_SHORT(c->predictor);
c->step = (c->step * yamaha_indexscale[nibble]) >> 8;
c->step = clip(c->step, 127, 24567);
return c->predictor;
}
static void xa_decode(short *out, const unsigned char *in,
ADPCMChannelStatus *left, ADPCMChannelStatus *right, int inc)
{
@ -978,6 +1043,22 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
break;
}
case CODEC_ID_ADPCM_YAMAHA:
while (src < buf + buf_size) {
if (st) {
*samples++ = adpcm_yamaha_expand_nibble(&c->status[0],
(src[0] >> 4) & 0x0F);
*samples++ = adpcm_yamaha_expand_nibble(&c->status[1],
src[0] & 0x0F);
} else {
*samples++ = adpcm_yamaha_expand_nibble(&c->status[0],
(src[0] >> 4) & 0x0F);
*samples++ = adpcm_yamaha_expand_nibble(&c->status[0],
src[0] & 0x0F);
}
src++;
}
break;
default:
return -1;
}
@ -1035,5 +1116,6 @@ ADPCM_CODEC(CODEC_ID_ADPCM_ADX, adpcm_adx);
ADPCM_CODEC(CODEC_ID_ADPCM_EA, adpcm_ea);
ADPCM_CODEC(CODEC_ID_ADPCM_CT, adpcm_ct);
ADPCM_CODEC(CODEC_ID_ADPCM_SWF, adpcm_swf);
ADPCM_CODEC(CODEC_ID_ADPCM_YAMAHA, adpcm_yamaha);
#undef ADPCM_CODEC

1
libavcodec/allcodecs.c
View File

@ -548,6 +548,7 @@ PCM_CODEC(CODEC_ID_ADPCM_EA, adpcm_ea);
PCM_CODEC(CODEC_ID_ADPCM_G726, adpcm_g726);
PCM_CODEC(CODEC_ID_ADPCM_CT, adpcm_ct);
PCM_CODEC(CODEC_ID_ADPCM_SWF, adpcm_swf);
PCM_CODEC(CODEC_ID_ADPCM_YAMAHA, adpcm_yamaha);
#undef PCM_CODEC

2
libavcodec/avcodec.h
View File

@ -137,6 +137,7 @@ enum CodecID {
CODEC_ID_ADPCM_G726,
CODEC_ID_ADPCM_CT,
CODEC_ID_ADPCM_SWF,
CODEC_ID_ADPCM_YAMAHA,
/* AMR */
CODEC_ID_AMR_NB= 0x12000,
@ -2119,6 +2120,7 @@ PCM_CODEC(CODEC_ID_ADPCM_EA, adpcm_ea);
PCM_CODEC(CODEC_ID_ADPCM_G726, adpcm_g726);
PCM_CODEC(CODEC_ID_ADPCM_CT, adpcm_ct);
PCM_CODEC(CODEC_ID_ADPCM_SWF, adpcm_swf);
PCM_CODEC(CODEC_ID_ADPCM_YAMAHA, adpcm_yamaha);
#undef PCM_CODEC