[SCM] libav/experimental: Add Yamaha ADPCM encoding/decoding patch by (Vidar Madsen: vidarino, gmail com)
siretart at users.alioth.debian.org
siretart at users.alioth.debian.org
Sun Jun 30 15:44:38 UTC 2013
The following commit has been merged in the experimental branch:
commit 2ff4524e7243a628e26d34bf353beeba4f217f61
Author: Vidar Madsen <vidarino at gmail.com>
Date: Fri Jul 15 06:51:36 2005 +0000
Add Yamaha ADPCM encoding/decoding patch by (Vidar Madsen: vidarino, gmail com)
Originally committed as revision 4442 to svn://svn.ffmpeg.org/ffmpeg/trunk
diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index 0c44121..67a9876 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -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
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index a0a7d7f..eb00ac4 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -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
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 8b113cd..178e65f 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -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
--
Libav/FFmpeg packaging
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