}
typedef struct G726Tables {
- int bits; /**< bits per sample */
const int* quant; /**< quantization table */
const int16_t* iquant; /**< inverse quantization table */
const int16_t* W; /**< special table #1 ;-) */
} 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 */
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<<dex) >> 7);
}
-static int16_t g726_decode(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 */
{
int i;
- c->tbls = &G726Tables_pool[index];
+ c->tbls = G726Tables_pool[index];
for (i=0; i<2; i++) {
c->sr[i].mant = 1<<5;
c->pk[i] = 1;
{
uint8_t i;
- i = quant(c, sig/4 - c->se) & ((1<<c->tbls->bits) - 1);
+ i = quant(c, sig/4 - c->se) & ((1<<c->code_size) - 1);
g726_decode(c, i);
return i;
}
/* Interfacing to the libavcodec */
-typedef struct AVG726Context {
- G726Context c;
- int code_size;
-} AVG726Context;
-
static av_cold int g726_init(AVCodecContext * avctx)
{
- AVG726Context* c = (AVG726Context*)avctx->priv_data;
+ G726Context* c = avctx->priv_data;
unsigned int index= (avctx->bit_rate + avctx->sample_rate/2) / avctx->sample_rate - 2;
if (avctx->bit_rate % avctx->sample_rate && avctx->codec->encode) {
av_log(avctx, AV_LOG_ERROR, "Unsupported number of bits %d\n", index+2);
return -1;
}
- g726_reset(&c->c, index);
- c->code_size = c->c.tbls->bits;
+ g726_reset(c, index);
+ c->code_size = index+2;
avctx->coded_frame = avcodec_alloc_frame();
if (!avctx->coded_frame)
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;
GetBitContext gb;
init_get_bits(&gb, buf, buf_size * 8);
while (get_bits_count(&gb) + c->code_size <= buf_size*8)
- *samples++ = g726_decode(&c->c, get_bits(&gb, c->code_size));
+ *samples++ = g726_decode(c, get_bits(&gb, c->code_size));
if(buf_size*8 != get_bits_count(&gb))
av_log(avctx, AV_LOG_ERROR, "Frame invalidly split, missing parser?\n");
"g726",
CODEC_TYPE_AUDIO,
CODEC_ID_ADPCM_G726,
- sizeof(AVG726Context),
+ sizeof(G726Context),
g726_init,
g726_encode_frame,
g726_close,
"g726",
CODEC_TYPE_AUDIO,
CODEC_ID_ADPCM_G726,
- sizeof(AVG726Context),
+ sizeof(G726Context),
g726_init,
NULL,
g726_close,