/*
* G.726 ADPCM audio codec
- * Copyright (c) 2004 Roman Shaposhnik.
+ * Copyright (c) 2004 Roman Shaposhnik
*
* This is a very straightforward rendition of the G.726
* Section 4 "Computational Details".
* instead of simply using 32bit integer arithmetic.
*/
typedef struct Float11 {
- int sign; /**< 1bit sign */
- int exp; /**< 4bit exponent */
- int mant; /**< 6bit mantissa */
+ uint8_t sign; /**< 1bit sign */
+ uint8_t exp; /**< 4bit exponent */
+ uint8_t mant; /**< 6bit mantissa */
} Float11;
-static inline Float11* i2f(int16_t i, Float11* f)
+static inline Float11* i2f(int i, Float11* f)
{
f->sign = (i < 0);
if (f->sign)
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);
+ res = (((f1->mant * f2->mant) + 0x30) >> 4);
+ res = exp > 19 ? res << (exp - 19) : res >> (19 - exp);
return (f1->sign ^ f2->sign) ? -res : res;
}
}
typedef struct G726Tables {
- int bits; /**< bits per sample */
const int* quant; /**< quantization table */
- const int* iquant; /**< inverse quantization table */
- const int* W; /**< special table #1 ;-) */
- const int* F; /**< special table #2 */
+ const int16_t* iquant; /**< inverse quantization table */
+ const int16_t* W; /**< special table #1 ;-) */
+ const uint8_t* F; /**< special table #2 */
} G726Tables;
typedef struct G726Context {
- const G726Tables* tbls; /**< static tables needed for computation */
+ G726Tables tbls; /**< static tables needed for computation */
Float11 sr[2]; /**< prev. reconstructed samples */
Float11 dq[6]; /**< prev. difference */
int se; /**< estimated signal for the next iteration */
int sez; /**< estimated second order prediction */
int y; /**< quantizer scaling factor for the next iteration */
+ int code_size;
} G726Context;
static const int quant_tbl16[] = /**< 16kbit/s 2bits per sample */
{ 260, INT_MAX };
-static const int iquant_tbl16[] =
+static const int16_t iquant_tbl16[] =
{ 116, 365, 365, 116 };
-static const int W_tbl16[] =
+static const int16_t W_tbl16[] =
{ -22, 439, 439, -22 };
-static const int F_tbl16[] =
+static const uint8_t F_tbl16[] =
{ 0, 7, 7, 0 };
static const int quant_tbl24[] = /**< 24kbit/s 3bits per sample */
{ 7, 217, 330, INT_MAX };
-static const int iquant_tbl24[] =
- { INT_MIN, 135, 273, 373, 373, 273, 135, INT_MIN };
-static const int W_tbl24[] =
+static const int16_t iquant_tbl24[] =
+ { INT16_MIN, 135, 273, 373, 373, 273, 135, INT16_MIN };
+static const int16_t W_tbl24[] =
{ -4, 30, 137, 582, 582, 137, 30, -4 };
-static const int F_tbl24[] =
+static const uint8_t F_tbl24[] =
{ 0, 1, 2, 7, 7, 2, 1, 0 };
static const int quant_tbl32[] = /**< 32kbit/s 4bits per sample */
{ -125, 79, 177, 245, 299, 348, 399, INT_MAX };
-static const int iquant_tbl32[] =
- { INT_MIN, 4, 135, 213, 273, 323, 373, 425,
- 425, 373, 323, 273, 213, 135, 4, INT_MIN };
-static const int W_tbl32[] =
+static const int16_t iquant_tbl32[] =
+ { INT16_MIN, 4, 135, 213, 273, 323, 373, 425,
+ 425, 373, 323, 273, 213, 135, 4, INT16_MIN };
+static const int16_t W_tbl32[] =
{ -12, 18, 41, 64, 112, 198, 355, 1122,
1122, 355, 198, 112, 64, 41, 18, -12};
-static const int F_tbl32[] =
+static const uint8_t F_tbl32[] =
{ 0, 0, 0, 1, 1, 1, 3, 7, 7, 3, 1, 1, 1, 0, 0, 0 };
static const 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 };
-static const int iquant_tbl40[] =
- { INT_MIN, -66, 28, 104, 169, 224, 274, 318,
+static const int16_t iquant_tbl40[] =
+ { INT16_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 const int W_tbl40[] =
+ 318, 274, 224, 169, 104, 28, -66, INT16_MIN };
+static const int16_t 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 const int F_tbl40[] =
+static const uint8_t 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 };
static const 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 },
- { 5, quant_tbl40, iquant_tbl40, W_tbl40, F_tbl40 }};
+ {{ quant_tbl16, iquant_tbl16, W_tbl16, F_tbl16 },
+ { quant_tbl24, iquant_tbl24, W_tbl24, F_tbl24 },
+ { quant_tbl32, iquant_tbl32, W_tbl32, F_tbl32 },
+ { quant_tbl40, iquant_tbl40, W_tbl40, F_tbl40 }};
/**
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)
+ 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 */
+ if (c->code_size != 2 && i == 0) /* I'm not sure this is a good idea */
i = 0xff;
return i;
{
int dql, dex, dqt;
- dql = c->tbls->iquant[i] + (c->y >> 2);
+ 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<<dex) >> 7);
}
-static inline int16_t g726_iterate(G726Context* c, int16_t I)
+static int16_t g726_decode(G726Context* c, int I)
{
int dq, re_signal, pk0, fa1, i, tr, ylint, ylfrac, thr2, al, dq0;
Float11 f;
+ int I_sig= I >> (c->code_size - 1);
dq = inverse_quant(c, I);
- if (I >> (c->tbls->bits - 1)) /* get the sign */
- dq = -dq;
- re_signal = c->se + dq;
/* Transition detect */
ylint = (c->yl >> 15);
ylfrac = (c->yl >> 10) & 0x1f;
thr2 = (ylint > 9) ? 0x1f << 10 : (0x20 + ylfrac) << ylint;
- if (c->td == 1 && abs(dq) > ((thr2+(thr2>>1))>>1))
- tr = 1;
- else
- tr = 0;
+ tr= (c->td == 1 && dq > ((3*thr2)>>2));
+
+ if (I_sig) /* get the sign */
+ dq = -dq;
+ re_signal = c->se + dq;
/* Update second order predictor coefficient A2 and A1 */
pk0 = (c->sez + dq) ? sgn(c->sez + dq) : 0;
for (i=5; i>0; i--)
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 ?!?! */
+ c->dq[0].sign = I_sig; /* 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 = 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;
+ c->dms += (c->tbls.F[I]<<4) + ((- c->dms) >> 5);
+ c->dml += (c->tbls.F[I]<<4) + ((- c->dml) >> 7);
if (tr)
c->ap = 256;
- else if (c->y > 1535 && !c->td && (abs((c->dms << 2) - c->dml) < (c->dml >> 3)))
+ else {
c->ap += (-c->ap) >> 4;
- else
- c->ap += (0x200 - c->ap) >> 4;
+ if (c->y <= 1535 || c->td || abs((c->dms << 2) - c->dml) >= (c->dml >> 3))
+ c->ap += 0x20;
+ }
/* Update Yu and Yl */
- c->yu = av_clip(c->y + (((c->tbls->W[I] << 5) - c->y) >> 5), 544, 5120);
+ c->yu = av_clip(c->y + c->tbls.W[I] + ((-c->y)>>5), 544, 5120);
c->yl += c->yu + ((-c->yl)>>6);
/* Next iteration for Y */
return av_clip(re_signal << 2, -0xffff, 0xffff);
}
-static int g726_reset(G726Context* c, int bit_rate)
+static av_cold int g726_reset(G726Context* c, int index)
{
int i;
- c->tbls = &G726Tables_pool[bit_rate/8000 - 2];
+ c->tbls = G726Tables_pool[index];
for (i=0; i<2; i++) {
- i2f(0, &c->sr[i]);
- c->a[i] = 0;
+ c->sr[i].mant = 1<<5;
c->pk[i] = 1;
}
for (i=0; i<6; i++) {
- i2f(0, &c->dq[i]);
- c->b[i] = 0;
+ c->dq[i].mant = 1<<5;
}
- c->ap = 0;
- c->dms = 0;
- c->dml = 0;
c->yu = 544;
c->yl = 34816;
- c->td = 0;
- c->se = 0;
- c->sez = 0;
c->y = 544;
return 0;
}
-static int16_t g726_decode(G726Context* c, int16_t i)
-{
- return g726_iterate(c, i);
-}
-
-#ifdef CONFIG_ENCODERS
+#if CONFIG_ADPCM_G726_ENCODER
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);
+ i = quant(c, sig/4 - c->se) & ((1<<c->code_size) - 1);
+ g726_decode(c, i);
return i;
}
#endif
/* Interfacing to the libavcodec */
-typedef struct AVG726Context {
- G726Context c;
- int bits_left;
- int bit_buffer;
- int code_size;
-} AVG726Context;
-
-static int g726_init(AVCodecContext * avctx)
+static av_cold int g726_init(AVCodecContext * avctx)
{
- AVG726Context* c = (AVG726Context*)avctx->priv_data;
+ G726Context* c = avctx->priv_data;
+ unsigned int index;
+
+ if (avctx->sample_rate <= 0) {
+ av_log(avctx, AV_LOG_ERROR, "Samplerate is invalid\n");
+ return -1;
+ }
+
+ index = (avctx->bit_rate + avctx->sample_rate/2) / avctx->sample_rate - 2;
- if (avctx->channels != 1 ||
- (avctx->bit_rate != 16000 && avctx->bit_rate != 24000 &&
- avctx->bit_rate != 32000 && avctx->bit_rate != 40000)) {
- av_log(avctx, AV_LOG_ERROR, "G726: unsupported audio format\n");
+ if (avctx->bit_rate % avctx->sample_rate && avctx->codec->encode) {
+ av_log(avctx, AV_LOG_ERROR, "Bitrate - Samplerate combination is invalid\n");
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");
+ if(avctx->channels != 1){
+ av_log(avctx, AV_LOG_ERROR, "Only mono is supported\n");
return -1;
}
- g726_reset(&c->c, avctx->bit_rate);
- c->code_size = c->c.tbls->bits;
- c->bit_buffer = 0;
- c->bits_left = 0;
+ if(index>3){
+ av_log(avctx, AV_LOG_ERROR, "Unsupported number of bits %d\n", index+2);
+ return -1;
+ }
+ g726_reset(c, index);
+ c->code_size = index+2;
avctx->coded_frame = avcodec_alloc_frame();
if (!avctx->coded_frame)
return AVERROR(ENOMEM);
avctx->coded_frame->key_frame = 1;
+ if (avctx->codec->decode)
+ avctx->sample_fmt = SAMPLE_FMT_S16;
+
return 0;
}
-static int g726_close(AVCodecContext *avctx)
+static av_cold int g726_close(AVCodecContext *avctx)
{
av_freep(&avctx->coded_frame);
return 0;
}
-#ifdef CONFIG_ENCODERS
+#if CONFIG_ADPCM_G726_ENCODER
static int g726_encode_frame(AVCodecContext *avctx,
uint8_t *dst, int buf_size, void *data)
{
- AVG726Context *c = avctx->priv_data;
+ G726Context *c = avctx->priv_data;
short *samples = data;
PutBitContext pb;
init_put_bits(&pb, dst, 1024*1024);
for (; buf_size; buf_size--)
- put_bits(&pb, c->code_size, g726_encode(&c->c, *samples++));
+ put_bits(&pb, c->code_size, g726_encode(c, *samples++));
flush_put_bits(&pb);
void *data, int *data_size,
const uint8_t *buf, int buf_size)
{
- AVG726Context *c = avctx->priv_data;
+ G726Context *c = avctx->priv_data;
short *samples = data;
- uint8_t code;
- uint8_t mask;
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);
- }
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, get_bits(&gb, c->code_size));
- c->bits_left = buf_size*8 - get_bits_count(&gb);
- c->bit_buffer = get_bits(&gb, c->bits_left);
+ if(buf_size*8 != get_bits_count(&gb))
+ av_log(avctx, AV_LOG_ERROR, "Frame invalidly split, missing parser?\n");
-out:
*data_size = (uint8_t*)samples - (uint8_t*)data;
return buf_size;
}
-#ifdef CONFIG_ENCODERS
+#if CONFIG_ADPCM_G726_ENCODER
AVCodec adpcm_g726_encoder = {
"g726",
CODEC_TYPE_AUDIO,
CODEC_ID_ADPCM_G726,
- sizeof(AVG726Context),
+ sizeof(G726Context),
g726_init,
g726_encode_frame,
g726_close,
NULL,
+ .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
+ .long_name = NULL_IF_CONFIG_SMALL("G.726 ADPCM"),
};
-#endif //CONFIG_ENCODERS
+#endif
AVCodec adpcm_g726_decoder = {
"g726",
CODEC_TYPE_AUDIO,
CODEC_ID_ADPCM_G726,
- sizeof(AVG726Context),
+ sizeof(G726Context),
g726_init,
NULL,
g726_close,
g726_decode_frame,
+ .long_name = NULL_IF_CONFIG_SMALL("G.726 ADPCM"),
};