43 #define MUL(a,b) (((int64_t)(a) * (int64_t)(b)) >> FRAC_BITS)
45 #define SAMPLES_BUF_SIZE 4096
68 float scale_factor_inv_table[64];
85 if (channels <= 0 || channels > 2){
86 av_log(avctx,
AV_LOG_ERROR,
"encoding %d channel(s) is not allowed in mp2\n", channels);
89 bitrate = bitrate / 1000;
92 avctx->
delay = 512 - 32 + 1;
137 av_dlog(avctx,
"%d kb/s, %d Hz, frame_size=%d bits, table=%d, padincr=%x\n",
157 v = (int)(
exp2((3 - i) / 3.0) * (1 << 20));
162 s->scale_factor_inv_table[i] =
exp2(-(3 - i) / 3.0) / (float)(1 << 20);
203 for(j=31;j>=3;j-=2) tab[j] += tab[j - 2];
247 x1 =
MUL((t[8] - x2), xp[0]);
248 x2 =
MUL((t[8] + x2), xp[1]);
261 xr =
MUL(t[28],xp[0]);
265 xr =
MUL(t[4],xp[1]);
266 t[ 4] = (t[24] - xr);
267 t[24] = (t[24] + xr);
269 xr =
MUL(t[20],xp[2]);
273 xr =
MUL(t[12],xp[3]);
274 t[12] = (t[16] - xr);
275 t[16] = (t[16] + xr);
280 for (i = 0; i < 4; i++) {
281 xr =
MUL(tab[30-i*4],xp[0]);
282 tab[30-i*4] = (tab[i*4] - xr);
283 tab[ i*4] = (tab[i*4] + xr);
285 xr =
MUL(tab[ 2+i*4],xp[1]);
286 tab[ 2+i*4] = (tab[28-i*4] - xr);
287 tab[28-i*4] = (tab[28-i*4] + xr);
289 xr =
MUL(tab[31-i*4],xp[0]);
290 tab[31-i*4] = (tab[1+i*4] - xr);
291 tab[ 1+i*4] = (tab[1+i*4] + xr);
293 xr =
MUL(tab[ 3+i*4],xp[1]);
294 tab[ 3+i*4] = (tab[29-i*4] - xr);
295 tab[29-i*4] = (tab[29-i*4] + xr);
303 xr =
MUL(t1[0], *xp);
316 #define WSHIFT (WFRAC_BITS + 15 - FRAC_BITS)
331 s->
samples_buf[ch][offset + (31 - i)] = samples[0];
340 sum = p[0*64] * q[0*64];
341 sum += p[1*64] * q[1*64];
342 sum += p[2*64] * q[2*64];
343 sum += p[3*64] * q[3*64];
344 sum += p[4*64] * q[4*64];
345 sum += p[5*64] * q[5*64];
346 sum += p[6*64] * q[6*64];
347 sum += p[7*64] * q[7*64];
352 tmp1[0] = tmp[16] >>
WSHIFT;
353 for( i=1; i<=16; i++ ) tmp1[i] = (tmp[i+16]+tmp[16-i]) >>
WSHIFT;
354 for( i=17; i<=31; i++ ) tmp1[i] = (tmp[i+16]-tmp[80-i]) >>
WSHIFT;
372 unsigned char scale_code[
SBLIMIT],
373 unsigned char scale_factors[SBLIMIT][3],
374 int sb_samples[3][12][SBLIMIT],
377 int *p, vmax,
v,
n, i, j, k, code;
379 unsigned char *sf = &scale_factors[0][0];
381 for(j=0;j<sblimit;j++) {
384 p = &sb_samples[i][0][j];
397 index = (21 -
n) * 3 - 3;
399 while (vmax <= s->scale_factor_table[index+1])
408 av_dlog(NULL,
"%2d:%d in=%x %x %d\n",
421 switch(d1 * 5 + d2) {
453 sf[1] = sf[2] = sf[0];
458 sf[0] = sf[1] = sf[2];
464 sf[0] = sf[2] = sf[1];
470 sf[1] = sf[2] = sf[0];
477 av_dlog(NULL,
"%d: %2d %2d %2d %d %d -> %d\n", j,
478 sf[0], sf[1], sf[2], d1, d2, code);
479 scale_code[j] = code;
497 #define SB_NOTALLOCATED 0
498 #define SB_ALLOCATED 1
509 int i, ch,
b, max_smr, max_ch, max_sb, current_frame_size, max_frame_size;
513 const unsigned char *alloc;
515 memcpy(smr, smr1, s->
nb_channels *
sizeof(
short) * SBLIMIT);
531 current_frame_size = 32;
545 if (smr[ch][i] > max_smr && subband_status[ch][i] !=
SB_NOMORE) {
546 max_smr = smr[ch][i];
554 av_dlog(NULL,
"current=%d max=%d max_sb=%d max_ch=%d alloc=%d\n",
555 current_frame_size, max_frame_size, max_sb, max_ch,
561 for(i=0;i<max_sb;i++) {
562 alloc += 1 << alloc[0];
576 if (current_frame_size + incr <= max_frame_size) {
579 current_frame_size += incr;
581 smr[max_ch][max_sb] = smr1[max_ch][max_sb] -
quant_snr[alloc[
b]];
583 if (b == ((1 << alloc[0]) - 1))
584 subband_status[max_ch][max_sb] =
SB_NOMORE;
589 subband_status[max_ch][max_sb] =
SB_NOMORE;
592 *padding = max_frame_size - current_frame_size;
604 int i, j, k, l, bit_alloc_bits,
b, ch;
632 j += 1 << bit_alloc_bits;
687 a = (float)sample * s->scale_factor_inv_table[s->
scale_factors[ch][i][k]];
688 q[m] = (
int)((a + 1.0) * steps * 0.5);
699 q1 = sample << (-
shift);
701 q1 = sample >>
shift;
702 q1 = (q1 *
mult) >>
P;
703 q[
m] = ((q1 + (1 <<
P)) * steps) >> (
P + 1);
716 q[0] + steps * (q[1] + steps * q[2]));
725 j += 1 << bit_alloc_bits;
731 for(i=0;i<padding;i++)
742 const int16_t *samples = (
const int16_t *)frame->
data[0];