/*
- * G.726 ADPCM audio codec
+ * G.726 ADPCM audio codec
* Copyright (c) 2004 Roman Shaposhnik.
*
* This is a very straightforward rendition of the G.726
- * Section 4 "Computational Details".
+ * Section 4 "Computational Details".
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
*
* 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
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <limits.h>
#include "avcodec.h"
/**
* G.726 11bit float.
- * G.726 Standard uses rather odd 11bit floating point arithmentic for
+ * G.726 Standard uses rather odd 11bit floating point arithmentic for
* numerous occasions. It's a mistery to me why they did it this way
* instead of simply using 32bit integer arithmetic.
*/
typedef struct Float11 {
- int sign; /**< 1bit sign */
- int exp; /**< 4bit exponent */
- int mant; /**< 6bit mantissa */
+ int sign; /**< 1bit sign */
+ int exp; /**< 4bit exponent */
+ int mant; /**< 6bit mantissa */
} Float11;
static inline Float11* i2f(int16_t i, Float11* f)
{
- f->sign = (i < 0);
- if (f->sign)
- i = -i;
- f->exp = av_log2_16bit(i) + !!i;
- f->mant = i? (i<<6) >> f->exp :
- 1<<5;
- return f;
+ f->sign = (i < 0);
+ if (f->sign)
+ i = -i;
+ f->exp = av_log2_16bit(i) + !!i;
+ f->mant = i? (i<<6) >> f->exp :
+ 1<<5;
+ return f;
}
static inline int16_t mult(Float11* f1, Float11* f2)
{
- int res, exp;
+ int res, exp;
- exp = f1->exp + f2->exp;
- res = (((f1->mant * f2->mant) + 0x30) >> 4) << 7;
- res = exp > 26 ? res << (exp - 26) : res >> (26 - exp);
- return (f1->sign ^ f2->sign) ? -res : res;
+ exp = f1->exp + f2->exp;
+ res = (((f1->mant * f2->mant) + 0x30) >> 4) << 7;
+ res = exp > 26 ? res << (exp - 26) : res >> (26 - exp);
+ return (f1->sign ^ f2->sign) ? -res : res;
}
static inline int sgn(int value)
}
typedef struct G726Tables {
- int bits; /**< bits per sample */
- int* quant; /**< quantization table */
- int* iquant; /**< inverse quantization table */
- int* W; /**< special table #1 ;-) */
- int* F; /**< special table #2 */
+ int bits; /**< bits per sample */
+ int* quant; /**< quantization table */
+ int* iquant; /**< inverse quantization table */
+ int* W; /**< special table #1 ;-) */
+ int* F; /**< special table #2 */
} G726Tables;
typedef struct G726Context {
- G726Tables* tbls; /**< static tables needed for computation */
-
- Float11 sr[2]; /**< prev. reconstructed samples */
- Float11 dq[6]; /**< prev. difference */
- int a[2]; /**< second order predictor coeffs */
- int b[6]; /**< sixth order predictor coeffs */
- int pk[2]; /**< signs of prev. 2 sez + dq */
-
- int ap; /**< scale factor control */
- int yu; /**< fast scale factor */
- int yl; /**< slow scale factor */
- int dms; /**< short average magnitude of F[i] */
- int dml; /**< long average magnitude of F[i] */
- int td; /**< tone detect */
-
- int se; /**< estimated signal for the next iteration */
- int sez; /**< estimated second order prediction */
- int y; /**< quantizer scaling factor for the next iteration */
+ G726Tables* tbls; /**< static tables needed for computation */
+
+ Float11 sr[2]; /**< prev. reconstructed samples */
+ Float11 dq[6]; /**< prev. difference */
+ int a[2]; /**< second order predictor coeffs */
+ int b[6]; /**< sixth order predictor coeffs */
+ int pk[2]; /**< signs of prev. 2 sez + dq */
+
+ int ap; /**< scale factor control */
+ int yu; /**< fast scale factor */
+ int yl; /**< slow scale factor */
+ int dms; /**< short average magnitude of F[i] */
+ int dml; /**< long average magnitude of F[i] */
+ int td; /**< tone detect */
+
+ int se; /**< estimated signal for the next iteration */
+ int sez; /**< estimated second order prediction */
+ int y; /**< quantizer scaling factor for the next iteration */
} G726Context;
static int quant_tbl16[] = /**< 16kbit/s 2bits per sample */
- { 260, INT_MAX };
+ { 260, INT_MAX };
static int iquant_tbl16[] =
{ 116, 365, 365, 116 };
-static int W_tbl16[] =
+static int W_tbl16[] =
{ -22, 439, 439, -22 };
static int F_tbl16[] =
{ 0, 7, 7, 0 };
-
+
static int quant_tbl24[] = /**< 24kbit/s 3bits per sample */
{ 7, 217, 330, INT_MAX };
static int iquant_tbl24[] =
{ INT_MIN, 135, 273, 373, 373, 273, 135, INT_MIN };
-static int W_tbl24[] =
- { -4, 30, 137, 582, 582, 137, 30, -4 };
+static int W_tbl24[] =
+ { -4, 30, 137, 582, 582, 137, 30, -4 };
static int F_tbl24[] =
{ 0, 1, 2, 7, 7, 2, 1, 0 };
-
+
static int quant_tbl32[] = /**< 32kbit/s 4bits per sample */
{ -125, 79, 177, 245, 299, 348, 399, INT_MAX };
static int iquant_tbl32[] =
- { INT_MIN, 4, 135, 213, 273, 323, 373, 425,
- 425, 373, 323, 273, 213, 135, 4, INT_MIN };
-static int W_tbl32[] =
+ { INT_MIN, 4, 135, 213, 273, 323, 373, 425,
+ 425, 373, 323, 273, 213, 135, 4, INT_MIN };
+static int W_tbl32[] =
{ -12, 18, 41, 64, 112, 198, 355, 1122,
- 1122, 355, 198, 112, 64, 41, 18, -12};
-static int F_tbl32[] =
+ 1122, 355, 198, 112, 64, 41, 18, -12};
+static int F_tbl32[] =
{ 0, 0, 0, 1, 1, 1, 3, 7, 7, 3, 1, 1, 1, 0, 0, 0 };
-
+
static int quant_tbl40[] = /**< 40kbit/s 5bits per sample */
{ -122, -16, 67, 138, 197, 249, 297, 338,
- 377, 412, 444, 474, 501, 527, 552, INT_MAX };
+ 377, 412, 444, 474, 501, 527, 552, INT_MAX };
static int iquant_tbl40[] =
- { INT_MIN, -66, 28, 104, 169, 224, 274, 318,
- 358, 395, 429, 459, 488, 514, 539, 566,
- 566, 539, 514, 488, 459, 429, 395, 358,
- 318, 274, 224, 169, 104, 28, -66, INT_MIN };
-static int W_tbl40[] =
+ { INT_MIN, -66, 28, 104, 169, 224, 274, 318,
+ 358, 395, 429, 459, 488, 514, 539, 566,
+ 566, 539, 514, 488, 459, 429, 395, 358,
+ 318, 274, 224, 169, 104, 28, -66, INT_MIN };
+static int W_tbl40[] =
{ 14, 14, 24, 39, 40, 41, 58, 100,
- 141, 179, 219, 280, 358, 440, 529, 696,
- 696, 529, 440, 358, 280, 219, 179, 141,
- 100, 58, 41, 40, 39, 24, 14, 14 };
-static int F_tbl40[] =
+ 141, 179, 219, 280, 358, 440, 529, 696,
+ 696, 529, 440, 358, 280, 219, 179, 141,
+ 100, 58, 41, 40, 39, 24, 14, 14 };
+static int F_tbl40[] =
{ 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 6,
- 6, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
+ 6, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
-static G726Tables G726Tables_pool[] =
+static G726Tables G726Tables_pool[] =
{{ 2, quant_tbl16, iquant_tbl16, W_tbl16, F_tbl16 },
- { 3, quant_tbl24, iquant_tbl24, W_tbl24, F_tbl24 },
- { 4, quant_tbl32, iquant_tbl32, W_tbl32, F_tbl32 },
+ { 3, quant_tbl24, iquant_tbl24, W_tbl24, F_tbl24 },
+ { 4, quant_tbl32, iquant_tbl32, W_tbl32, F_tbl32 },
{ 5, quant_tbl40, iquant_tbl40, W_tbl40, F_tbl40 }};
-
+
/**
- * Para 4.2.2 page 18: Adaptive quantizer.
+ * Para 4.2.2 page 18: Adaptive quantizer.
*/
static inline uint8_t quant(G726Context* c, int d)
{
int sign, exp, i, dln;
-
+
sign = i = 0;
if (d < 0) {
sign = 1;
}
exp = av_log2_16bit(d);
dln = ((exp<<7) + (((d<<7)>>exp)&0x7f)) - (c->y>>2);
-
+
while (c->tbls->quant[i] < INT_MAX && c->tbls->quant[i] < dln)
++i;
-
+
if (sign)
i = ~i;
if (c->tbls->bits != 2 && i == 0) /* I'm not sure this is a good idea */
i = 0xff;
- return i;
+ return i;
}
/**
static inline int16_t inverse_quant(G726Context* c, int i)
{
int dql, dex, dqt;
-
+
dql = c->tbls->iquant[i] + (c->y >> 2);
dex = (dql>>7) & 0xf; /* 4bit exponent */
dqt = (1<<7) + (dql & 0x7f); /* log2 -> linear */
- return (dql < 0) ? 0 : ((dqt<<7) >> (14-dex));
+ return (dql < 0) ? 0 : ((dqt<<7) >> (14-dex));
}
static inline int16_t g726_iterate(G726Context* c, int16_t I)
{
int dq, re_signal, pk0, fa1, i, tr, ylint, ylfrac, thr2, al, dq0;
Float11 f;
-
+
dq = inverse_quant(c, I);
if (I >> (c->tbls->bits - 1)) /* get the sign */
dq = -dq;
tr = 1;
else
tr = 0;
-
+
/* Update second order predictor coefficient A2 and A1 */
pk0 = (c->sez + dq) ? sgn(c->sez + dq) : 0;
dq0 = dq ? sgn(dq) : 0;
if (tr) {
c->a[0] = 0;
- c->a[1] = 0;
+ c->a[1] = 0;
for (i=0; i<6; i++)
- c->b[i] = 0;
+ c->b[i] = 0;
} else {
- /* This is a bit crazy, but it really is +255 not +256 */
- fa1 = clip((-c->a[0]*c->pk[0]*pk0)>>5, -256, 255);
-
- c->a[1] += 128*pk0*c->pk[1] + fa1 - (c->a[1]>>7);
- c->a[1] = clip(c->a[1], -12288, 12288);
+ /* This is a bit crazy, but it really is +255 not +256 */
+ fa1 = clip((-c->a[0]*c->pk[0]*pk0)>>5, -256, 255);
+
+ c->a[1] += 128*pk0*c->pk[1] + fa1 - (c->a[1]>>7);
+ c->a[1] = clip(c->a[1], -12288, 12288);
c->a[0] += 64*3*pk0*c->pk[0] - (c->a[0] >> 8);
- c->a[0] = clip(c->a[0], -(15360 - c->a[1]), 15360 - c->a[1]);
+ c->a[0] = clip(c->a[0], -(15360 - c->a[1]), 15360 - c->a[1]);
for (i=0; i<6; i++)
- c->b[i] += 128*dq0*sgn(-c->dq[i].sign) - (c->b[i]>>8);
+ c->b[i] += 128*dq0*sgn(-c->dq[i].sign) - (c->b[i]>>8);
}
/* Update Dq and Sr and Pk */
c->dq[i] = c->dq[i-1];
i2f(dq, &c->dq[0]);
c->dq[0].sign = I >> (c->tbls->bits - 1); /* Isn't it crazy ?!?! */
-
+
/* Update tone detect [I'm not sure 'tr == 0' is really needed] */
- c->td = (tr == 0 && c->a[1] < -11776);
-
+ c->td = (tr == 0 && c->a[1] < -11776);
+
/* Update Ap */
c->dms += ((c->tbls->F[I]<<9) - c->dms) >> 5;
c->dml += ((c->tbls->F[I]<<11) - c->dml) >> 7;
- if (tr)
+ if (tr)
c->ap = 256;
else if (c->y > 1535 && !c->td && (abs((c->dms << 2) - c->dml) < (c->dml >> 3)))
c->ap += (-c->ap) >> 4;
else
- c->ap += (0x200 - c->ap) >> 4;
+ c->ap += (0x200 - c->ap) >> 4;
/* Update Yu and Yl */
c->yu = clip(c->y + (((c->tbls->W[I] << 5) - c->y) >> 5), 544, 5120);
c->yl += c->yu + ((-c->yl)>>6);
-
+
/* Next iteration for Y */
al = (c->ap >= 256) ? 1<<6 : c->ap >> 2;
c->y = (c->yl + (c->yu - (c->yl>>6))*al) >> 6;
-
+
/* Next iteration for SE and SEZ */
c->se = 0;
for (i=0; i<6; i++)
return g726_iterate(c, i);
}
+#ifdef CONFIG_ENCODERS
static int16_t g726_encode(G726Context* c, int16_t sig)
{
uint8_t i;
-
+
i = quant(c, sig/4 - c->se) & ((1<<c->tbls->bits) - 1);
g726_iterate(c, i);
return i;
}
+#endif
/* Interfacing to the libavcodec */
static int g726_init(AVCodecContext * avctx)
{
AVG726Context* c = (AVG726Context*)avctx->priv_data;
-
+
if (avctx->channels != 1 ||
(avctx->bit_rate != 16000 && avctx->bit_rate != 24000 &&
- avctx->bit_rate != 32000 && avctx->bit_rate != 40000)) {
+ avctx->bit_rate != 32000 && avctx->bit_rate != 40000)) {
av_log(avctx, AV_LOG_ERROR, "G726: unsupported audio format\n");
- return -1;
+ return -1;
}
if (avctx->sample_rate != 8000 && avctx->strict_std_compliance>FF_COMPLIANCE_INOFFICIAL) {
av_log(avctx, AV_LOG_ERROR, "G726: unsupported audio format\n");
- return -1;
+ return -1;
}
g726_reset(&c->c, avctx->bit_rate);
c->code_size = c->c.tbls->bits;
return 0;
}
+#ifdef CONFIG_ENCODERS
static int g726_encode_frame(AVCodecContext *avctx,
uint8_t *dst, int buf_size, void *data)
{
flush_put_bits(&pb);
- return put_bits_count(&pb)>>3;
-}
+ return put_bits_count(&pb)>>3;
+}
+#endif
static int g726_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
short *samples = data;
uint8_t code;
uint8_t mask;
- GetBitContext gb;
-
+ GetBitContext gb;
+
if (!buf_size)
goto out;
-
+
mask = (1<<c->code_size) - 1;
init_get_bits(&gb, buf, buf_size * 8);
if (c->bits_left) {
int s = c->code_size - c->bits_left;;
- code = (c->bit_buffer << s) | get_bits(&gb, s);
- *samples++ = g726_decode(&c->c, code & mask);
+ code = (c->bit_buffer << s) | get_bits(&gb, s);
+ *samples++ = g726_decode(&c->c, code & mask);
}
-
+
while (get_bits_count(&gb) + c->code_size <= buf_size*8)
- *samples++ = g726_decode(&c->c, get_bits(&gb, c->code_size) & mask);
-
+ *samples++ = g726_decode(&c->c, get_bits(&gb, c->code_size) & mask);
+
c->bits_left = buf_size*8 - get_bits_count(&gb);
c->bit_buffer = get_bits(&gb, c->bits_left);
-
+
out:
*data_size = (uint8_t*)samples - (uint8_t*)data;
return buf_size;
projects / ffmpeg / blobdiff