38 #define MUL(a,b) (((int64_t)(a) * (int64_t)(b)) >> FRAC_BITS)
40 #define SAMPLES_BUF_SIZE 4096
76 if (channels <= 0 || channels > 2){
77 av_log(avctx,
AV_LOG_ERROR,
"encoding %d channel(s) is not allowed in mp2\n", channels);
80 bitrate = bitrate / 1000;
127 av_dlog(avctx,
"%d kb/s, %d Hz, frame_size=%d bits, table=%d, padincr=%x\n",
147 v = (int)(pow(2.0, (3 - i) / 3.0) * (1 << 20));
152 scale_factor_inv_table[i] = pow(2.0, -(3 - i) / 3.0) / (float)(1 << 20);
196 for(j=31;j>=3;j-=2) tab[j] += tab[j - 2];
240 x1 =
MUL((t[8] - x2), xp[0]);
241 x2 =
MUL((t[8] + x2), xp[1]);
254 xr =
MUL(t[28],xp[0]);
258 xr =
MUL(t[4],xp[1]);
259 t[ 4] = (t[24] - xr);
260 t[24] = (t[24] + xr);
262 xr =
MUL(t[20],xp[2]);
266 xr =
MUL(t[12],xp[3]);
267 t[12] = (t[16] - xr);
268 t[16] = (t[16] + xr);
273 for (i = 0; i < 4; i++) {
274 xr =
MUL(tab[30-i*4],xp[0]);
275 tab[30-i*4] = (tab[i*4] - xr);
276 tab[ i*4] = (tab[i*4] + xr);
278 xr =
MUL(tab[ 2+i*4],xp[1]);
279 tab[ 2+i*4] = (tab[28-i*4] - xr);
280 tab[28-i*4] = (tab[28-i*4] + xr);
282 xr =
MUL(tab[31-i*4],xp[0]);
283 tab[31-i*4] = (tab[1+i*4] - xr);
284 tab[ 1+i*4] = (tab[1+i*4] + xr);
286 xr =
MUL(tab[ 3+i*4],xp[1]);
287 tab[ 3+i*4] = (tab[29-i*4] - xr);
288 tab[29-i*4] = (tab[29-i*4] + xr);
296 xr =
MUL(t1[0], *xp);
309 #define WSHIFT (WFRAC_BITS + 15 - FRAC_BITS)
314 int sum, offset, i, j;
324 s->
samples_buf[ch][offset + (31 - i)] = samples[0];
333 sum = p[0*64] * q[0*64];
334 sum += p[1*64] * q[1*64];
335 sum += p[2*64] * q[2*64];
336 sum += p[3*64] * q[3*64];
337 sum += p[4*64] * q[4*64];
338 sum += p[5*64] * q[5*64];
339 sum += p[6*64] * q[6*64];
340 sum += p[7*64] * q[7*64];
345 tmp1[0] = tmp[16] >>
WSHIFT;
346 for( i=1; i<=16; i++ ) tmp1[i] = (tmp[i+16]+tmp[16-i]) >>
WSHIFT;
347 for( i=17; i<=31; i++ ) tmp1[i] = (tmp[i+16]-tmp[80-i]) >>
WSHIFT;
365 unsigned char scale_factors[SBLIMIT][3],
366 int sb_samples[3][12][SBLIMIT],
369 int *p, vmax,
v, n, i, j, k, code;
371 unsigned char *sf = &scale_factors[0][0];
373 for(j=0;j<sblimit;j++) {
376 p = &sb_samples[i][0][j];
389 index = (21 - n) * 3 - 3;
403 assert(index >=0 && index <= 63);
413 switch(d1 * 5 + d2) {
445 sf[1] = sf[2] = sf[0];
450 sf[0] = sf[1] = sf[2];
456 sf[0] = sf[2] = sf[1];
462 sf[1] = sf[2] = sf[0];
470 sf[0], sf[1], sf[2], d1, d2, code);
471 scale_code[j] = code;
489 #define SB_NOTALLOCATED 0
490 #define SB_ALLOCATED 1
501 int i, ch,
b, max_smr, max_ch, max_sb, current_frame_size, max_frame_size;
505 const unsigned char *alloc;
507 memcpy(smr, smr1, s->
nb_channels *
sizeof(
short) * SBLIMIT);
523 current_frame_size = 32;
537 if (smr[ch][i] > max_smr && subband_status[ch][i] !=
SB_NOMORE) {
538 max_smr = smr[ch][i];
546 av_dlog(
NULL,
"current=%d max=%d max_sb=%d max_ch=%d alloc=%d\n",
547 current_frame_size, max_frame_size, max_sb, max_ch,
553 for(i=0;i<max_sb;i++) {
554 alloc += 1 << alloc[0];
568 if (current_frame_size + incr <= max_frame_size) {
571 current_frame_size += incr;
573 smr[max_ch][max_sb] = smr1[max_ch][max_sb] -
quant_snr[alloc[
b]];
575 if (b == ((1 << alloc[0]) - 1))
576 subband_status[max_ch][max_sb] =
SB_NOMORE;
581 subband_status[max_ch][max_sb] =
SB_NOMORE;
584 *padding = max_frame_size - current_frame_size;
585 assert(*padding >= 0);
596 int i, j, k, l, bit_alloc_bits,
b, ch;
624 j += 1 << bit_alloc_bits;
669 int qindex, steps, m, sample,
bits;
679 a = (float)sample * scale_factor_inv_table[s->
scale_factors[ch][i][k]];
680 q[m] = (
int)((a + 1.0) * steps * 0.5);
684 int q1, e, shift,
mult;
691 q1 = sample << (-shift);
693 q1 = sample >> shift;
694 q1 = (q1 *
mult) >> P;
695 q[m] = ((q1 + (1 << P)) * steps) >> (P + 1);
700 assert(q[m] >= 0 && q[m] < steps);
706 q[0] + steps * (q[1] + steps * q[2]));
715 j += 1 << bit_alloc_bits;
721 for(i=0;i<padding;i++)
729 unsigned char *frame,
int buf_size,
void *
data)
777 .supported_samplerates= (
const int[]){44100, 48000, 32000, 22050, 24000, 16000, 0},