3 * Copyright (c) 2001, 2002 Fabrice Bellard.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 * @file mpegaudiodec.c
27 #include "bitstream.h"
32 * - in low precision mode, use more 16 bit multiplies in synth filter
33 * - test lsf / mpeg25 extensively.
36 /* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
38 #ifdef CONFIG_MPEGAUDIO_HP
39 #define USE_HIGHPRECISION
42 #include "mpegaudio.h"
44 #define FRAC_ONE (1 << FRAC_BITS)
46 #define MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> FRAC_BITS)
47 #define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))
48 #define FIX(a) ((int)((a) * FRAC_ONE))
49 /* WARNING: only correct for posititive numbers */
50 #define FIXR(a) ((int)((a) * FRAC_ONE + 0.5))
51 #define FRAC_RND(a) (((a) + (FRAC_ONE/2)) >> FRAC_BITS)
53 #define FIXHR(a) ((int)((a) * (1LL<<32) + 0.5))
54 //#define MULH(a,b) (((int64_t)(a) * (int64_t)(b))>>32) //gcc 3.4 creates an incredibly bloated mess out of this
55 static always_inline int MULH(int a, int b){
56 return ((int64_t)(a) * (int64_t)(b))>>32;
62 #define BACKSTEP_SIZE 512
66 typedef struct MPADecodeContext {
67 uint8_t inbuf1[2][MPA_MAX_CODED_FRAME_SIZE + BACKSTEP_SIZE]; /* input buffer */
69 uint8_t *inbuf_ptr, *inbuf;
71 int free_format_frame_size; /* frame size in case of free format
72 (zero if currently unknown) */
73 /* next header (used in free format parsing) */
74 uint32_t free_format_next_header;
78 int sample_rate_index; /* between 0 and 8 */
86 MPA_INT synth_buf[MPA_MAX_CHANNELS][512 * 2] __attribute__((aligned(16)));
87 int synth_buf_offset[MPA_MAX_CHANNELS];
88 int32_t sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT] __attribute__((aligned(16)));
89 int32_t mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
93 void (*compute_antialias)(struct MPADecodeContext *s, struct GranuleDef *g);
94 int adu_mode; ///< 0 for standard mp3, 1 for adu formatted mp3
95 unsigned int dither_state;
99 * Context for MP3On4 decoder
101 typedef struct MP3On4DecodeContext {
102 int frames; ///< number of mp3 frames per block (number of mp3 decoder instances)
103 int chan_cfg; ///< channel config number
104 MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance
105 } MP3On4DecodeContext;
107 /* layer 3 "granule" */
108 typedef struct GranuleDef {
113 int scalefac_compress;
115 uint8_t switch_point;
117 int subblock_gain[3];
118 uint8_t scalefac_scale;
119 uint8_t count1table_select;
120 int region_size[3]; /* number of huffman codes in each region */
122 int short_start, long_end; /* long/short band indexes */
123 uint8_t scale_factors[40];
124 int32_t sb_hybrid[SBLIMIT * 18]; /* 576 samples */
127 #define MODE_EXT_MS_STEREO 2
128 #define MODE_EXT_I_STEREO 1
130 /* layer 3 huffman tables */
131 typedef struct HuffTable {
134 const uint16_t *codes;
137 #include "mpegaudiodectab.h"
139 static void compute_antialias_integer(MPADecodeContext *s, GranuleDef *g);
140 static void compute_antialias_float(MPADecodeContext *s, GranuleDef *g);
142 /* vlc structure for decoding layer 3 huffman tables */
143 static VLC huff_vlc[16];
144 static uint8_t *huff_code_table[16];
145 static VLC huff_quad_vlc[2];
146 /* computed from band_size_long */
147 static uint16_t band_index_long[9][23];
148 /* XXX: free when all decoders are closed */
149 #define TABLE_4_3_SIZE (8191 + 16)*4
150 static int8_t *table_4_3_exp;
151 static uint32_t *table_4_3_value;
152 /* intensity stereo coef table */
153 static int32_t is_table[2][16];
154 static int32_t is_table_lsf[2][2][16];
155 static int32_t csa_table[8][4];
156 static float csa_table_float[8][4];
157 static int32_t mdct_win[8][36];
159 /* lower 2 bits: modulo 3, higher bits: shift */
160 static uint16_t scale_factor_modshift[64];
161 /* [i][j]: 2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
162 static int32_t scale_factor_mult[15][3];
163 /* mult table for layer 2 group quantization */
165 #define SCALE_GEN(v) \
166 { FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) }
168 static const int32_t scale_factor_mult2[3][3] = {
169 SCALE_GEN(4.0 / 3.0), /* 3 steps */
170 SCALE_GEN(4.0 / 5.0), /* 5 steps */
171 SCALE_GEN(4.0 / 9.0), /* 9 steps */
174 void ff_mpa_synth_init(MPA_INT *window);
175 static MPA_INT window[512] __attribute__((aligned(16)));
177 /* layer 1 unscaling */
178 /* n = number of bits of the mantissa minus 1 */
179 static inline int l1_unscale(int n, int mant, int scale_factor)
184 shift = scale_factor_modshift[scale_factor];
187 val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
189 /* NOTE: at this point, 1 <= shift >= 21 + 15 */
190 return (int)((val + (1LL << (shift - 1))) >> shift);
193 static inline int l2_unscale_group(int steps, int mant, int scale_factor)
197 shift = scale_factor_modshift[scale_factor];
201 val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
202 /* NOTE: at this point, 0 <= shift <= 21 */
204 val = (val + (1 << (shift - 1))) >> shift;
208 /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
209 static inline int l3_unscale(int value, int exponent)
214 e = table_4_3_exp [4*value + (exponent&3)];
215 m = table_4_3_value[4*value + (exponent&3)];
216 e -= (exponent >> 2);
220 m = (m + (1 << (e-1))) >> e;
225 /* all integer n^(4/3) computation code */
228 #define POW_FRAC_BITS 24
229 #define POW_FRAC_ONE (1 << POW_FRAC_BITS)
230 #define POW_FIX(a) ((int)((a) * POW_FRAC_ONE))
231 #define POW_MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> POW_FRAC_BITS)
233 static int dev_4_3_coefs[DEV_ORDER];
236 static int pow_mult3[3] = {
238 POW_FIX(1.25992104989487316476),
239 POW_FIX(1.58740105196819947474),
243 static void int_pow_init(void)
248 for(i=0;i<DEV_ORDER;i++) {
249 a = POW_MULL(a, POW_FIX(4.0 / 3.0) - i * POW_FIX(1.0)) / (i + 1);
250 dev_4_3_coefs[i] = a;
254 #if 0 /* unused, remove? */
255 /* return the mantissa and the binary exponent */
256 static int int_pow(int i, int *exp_ptr)
264 while (a < (1 << (POW_FRAC_BITS - 1))) {
268 a -= (1 << POW_FRAC_BITS);
270 for(j = DEV_ORDER - 1; j >= 0; j--)
271 a1 = POW_MULL(a, dev_4_3_coefs[j] + a1);
272 a = (1 << POW_FRAC_BITS) + a1;
273 /* exponent compute (exact) */
277 a = POW_MULL(a, pow_mult3[er]);
278 while (a >= 2 * POW_FRAC_ONE) {
282 /* convert to float */
283 while (a < POW_FRAC_ONE) {
287 /* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */
288 #if POW_FRAC_BITS > FRAC_BITS
289 a = (a + (1 << (POW_FRAC_BITS - FRAC_BITS - 1))) >> (POW_FRAC_BITS - FRAC_BITS);
290 /* correct overflow */
291 if (a >= 2 * (1 << FRAC_BITS)) {
301 static int decode_init(AVCodecContext * avctx)
303 MPADecodeContext *s = avctx->priv_data;
307 #if defined(USE_HIGHPRECISION) && defined(CONFIG_AUDIO_NONSHORT)
308 avctx->sample_fmt= SAMPLE_FMT_S32;
310 avctx->sample_fmt= SAMPLE_FMT_S16;
313 if(avctx->antialias_algo != FF_AA_FLOAT)
314 s->compute_antialias= compute_antialias_integer;
316 s->compute_antialias= compute_antialias_float;
318 if (!init && !avctx->parse_only) {
319 /* scale factors table for layer 1/2 */
322 /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
325 scale_factor_modshift[i] = mod | (shift << 2);
328 /* scale factor multiply for layer 1 */
332 norm = ((int64_t_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
333 scale_factor_mult[i][0] = MULL(FIXR(1.0 * 2.0), norm);
334 scale_factor_mult[i][1] = MULL(FIXR(0.7937005259 * 2.0), norm);
335 scale_factor_mult[i][2] = MULL(FIXR(0.6299605249 * 2.0), norm);
336 dprintf("%d: norm=%x s=%x %x %x\n",
338 scale_factor_mult[i][0],
339 scale_factor_mult[i][1],
340 scale_factor_mult[i][2]);
343 ff_mpa_synth_init(window);
345 /* huffman decode tables */
346 huff_code_table[0] = NULL;
348 const HuffTable *h = &mpa_huff_tables[i];
356 init_vlc(&huff_vlc[i], 8, n,
357 h->bits, 1, 1, h->codes, 2, 2, 1);
359 code_table = av_mallocz(n);
361 for(x=0;x<xsize;x++) {
363 code_table[j++] = (x << 4) | y;
365 huff_code_table[i] = code_table;
368 init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
369 mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1, 1);
375 band_index_long[i][j] = k;
376 k += band_size_long[i][j];
378 band_index_long[i][22] = k;
381 /* compute n ^ (4/3) and store it in mantissa/exp format */
382 table_4_3_exp= av_mallocz_static(TABLE_4_3_SIZE * sizeof(table_4_3_exp[0]));
385 table_4_3_value= av_mallocz_static(TABLE_4_3_SIZE * sizeof(table_4_3_value[0]));
390 for(i=1;i<TABLE_4_3_SIZE;i++) {
393 f = pow((double)(i/4), 4.0 / 3.0) * pow(2, (i&3)*0.25);
395 m = (uint32_t)(fm*(1LL<<31) + 0.5);
396 e+= FRAC_BITS - 31 + 5;
398 /* normalized to FRAC_BITS */
399 table_4_3_value[i] = m;
400 // av_log(NULL, AV_LOG_DEBUG, "%d %d %f\n", i, m, pow((double)i, 4.0 / 3.0));
401 table_4_3_exp[i] = -e;
408 f = tan((double)i * M_PI / 12.0);
409 v = FIXR(f / (1.0 + f));
414 is_table[1][6 - i] = v;
418 is_table[0][i] = is_table[1][i] = 0.0;
425 e = -(j + 1) * ((i + 1) >> 1);
426 f = pow(2.0, e / 4.0);
428 is_table_lsf[j][k ^ 1][i] = FIXR(f);
429 is_table_lsf[j][k][i] = FIXR(1.0);
430 dprintf("is_table_lsf %d %d: %x %x\n",
431 i, j, is_table_lsf[j][0][i], is_table_lsf[j][1][i]);
438 cs = 1.0 / sqrt(1.0 + ci * ci);
440 csa_table[i][0] = FIXHR(cs/4);
441 csa_table[i][1] = FIXHR(ca/4);
442 csa_table[i][2] = FIXHR(ca/4) + FIXHR(cs/4);
443 csa_table[i][3] = FIXHR(ca/4) - FIXHR(cs/4);
444 csa_table_float[i][0] = cs;
445 csa_table_float[i][1] = ca;
446 csa_table_float[i][2] = ca + cs;
447 csa_table_float[i][3] = ca - cs;
448 // printf("%d %d %d %d\n", FIX(cs), FIX(cs-1), FIX(ca), FIX(cs)-FIX(ca));
449 // av_log(NULL, AV_LOG_DEBUG,"%f %f %f %f\n", cs, ca, ca+cs, ca-cs);
452 /* compute mdct windows */
460 d= sin(M_PI * (i + 0.5) / 36.0);
463 else if(i>=24) d= sin(M_PI * (i - 18 + 0.5) / 12.0);
467 else if(i< 12) d= sin(M_PI * (i - 6 + 0.5) / 12.0);
470 //merge last stage of imdct into the window coefficients
471 d*= 0.5 / cos(M_PI*(2*i + 19)/72);
474 mdct_win[j][i/3] = FIXHR((d / (1<<5)));
476 mdct_win[j][i ] = FIXHR((d / (1<<5)));
477 // av_log(NULL, AV_LOG_DEBUG, "%2d %d %f\n", i,j,d / (1<<5));
481 /* NOTE: we do frequency inversion adter the MDCT by changing
482 the sign of the right window coefs */
485 mdct_win[j + 4][i] = mdct_win[j][i];
486 mdct_win[j + 4][i + 1] = -mdct_win[j][i + 1];
492 printf("win%d=\n", j);
494 printf("%f, ", (double)mdct_win[j][i] / FRAC_ONE);
502 s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
503 s->inbuf_ptr = s->inbuf;
507 if (avctx->codec_id == CODEC_ID_MP3ADU)
512 /* tab[i][j] = 1.0 / (2.0 * cos(pi*(2*k+1) / 2^(6 - j))) */
516 #define COS0_0 FIXR(0.50060299823519630134)
517 #define COS0_1 FIXR(0.50547095989754365998)
518 #define COS0_2 FIXR(0.51544730992262454697)
519 #define COS0_3 FIXR(0.53104259108978417447)
520 #define COS0_4 FIXR(0.55310389603444452782)
521 #define COS0_5 FIXR(0.58293496820613387367)
522 #define COS0_6 FIXR(0.62250412303566481615)
523 #define COS0_7 FIXR(0.67480834145500574602)
524 #define COS0_8 FIXR(0.74453627100229844977)
525 #define COS0_9 FIXR(0.83934964541552703873)
526 #define COS0_10 FIXR(0.97256823786196069369)
527 #define COS0_11 FIXR(1.16943993343288495515)
528 #define COS0_12 FIXR(1.48416461631416627724)
529 #define COS0_13 FIXR(2.05778100995341155085)
530 #define COS0_14 FIXR(3.40760841846871878570)
531 #define COS0_15 FIXR(10.19000812354805681150)
533 #define COS1_0 FIXR(0.50241928618815570551)
534 #define COS1_1 FIXR(0.52249861493968888062)
535 #define COS1_2 FIXR(0.56694403481635770368)
536 #define COS1_3 FIXR(0.64682178335999012954)
537 #define COS1_4 FIXR(0.78815462345125022473)
538 #define COS1_5 FIXR(1.06067768599034747134)
539 #define COS1_6 FIXR(1.72244709823833392782)
540 #define COS1_7 FIXR(5.10114861868916385802)
542 #define COS2_0 FIXR(0.50979557910415916894)
543 #define COS2_1 FIXR(0.60134488693504528054)
544 #define COS2_2 FIXR(0.89997622313641570463)
545 #define COS2_3 FIXR(2.56291544774150617881)
547 #define COS3_0 FIXR(0.54119610014619698439)
548 #define COS3_1 FIXR(1.30656296487637652785)
550 #define COS4_0 FIXR(0.70710678118654752439)
552 /* butterfly operator */
555 tmp0 = tab[a] + tab[b];\
556 tmp1 = tab[a] - tab[b];\
558 tab[b] = MULL(tmp1, c);\
561 #define BF1(a, b, c, d)\
568 #define BF2(a, b, c, d)\
578 #define ADD(a, b) tab[a] += tab[b]
580 /* DCT32 without 1/sqrt(2) coef zero scaling. */
581 static void dct32(int32_t *out, int32_t *tab)
713 out[ 1] = tab[16] + tab[24];
714 out[17] = tab[17] + tab[25];
715 out[ 9] = tab[18] + tab[26];
716 out[25] = tab[19] + tab[27];
717 out[ 5] = tab[20] + tab[28];
718 out[21] = tab[21] + tab[29];
719 out[13] = tab[22] + tab[30];
720 out[29] = tab[23] + tab[31];
721 out[ 3] = tab[24] + tab[20];
722 out[19] = tab[25] + tab[21];
723 out[11] = tab[26] + tab[22];
724 out[27] = tab[27] + tab[23];
725 out[ 7] = tab[28] + tab[18];
726 out[23] = tab[29] + tab[19];
727 out[15] = tab[30] + tab[17];
733 static inline int round_sample(int *sum)
736 sum1 = (*sum) >> OUT_SHIFT;
737 *sum &= (1<<OUT_SHIFT)-1;
740 else if (sum1 > OUT_MAX)
745 #if defined(ARCH_POWERPC_405)
747 /* signed 16x16 -> 32 multiply add accumulate */
748 #define MACS(rt, ra, rb) \
749 asm ("maclhw %0, %2, %3" : "=r" (rt) : "0" (rt), "r" (ra), "r" (rb));
751 /* signed 16x16 -> 32 multiply */
752 #define MULS(ra, rb) \
753 ({ int __rt; asm ("mullhw %0, %1, %2" : "=r" (__rt) : "r" (ra), "r" (rb)); __rt; })
757 /* signed 16x16 -> 32 multiply add accumulate */
758 #define MACS(rt, ra, rb) rt += (ra) * (rb)
760 /* signed 16x16 -> 32 multiply */
761 #define MULS(ra, rb) ((ra) * (rb))
767 static inline int round_sample(int64_t *sum)
770 sum1 = (int)((*sum) >> OUT_SHIFT);
771 *sum &= (1<<OUT_SHIFT)-1;
774 else if (sum1 > OUT_MAX)
779 #define MULS(ra, rb) MUL64(ra, rb)
783 #define SUM8(sum, op, w, p) \
785 sum op MULS((w)[0 * 64], p[0 * 64]);\
786 sum op MULS((w)[1 * 64], p[1 * 64]);\
787 sum op MULS((w)[2 * 64], p[2 * 64]);\
788 sum op MULS((w)[3 * 64], p[3 * 64]);\
789 sum op MULS((w)[4 * 64], p[4 * 64]);\
790 sum op MULS((w)[5 * 64], p[5 * 64]);\
791 sum op MULS((w)[6 * 64], p[6 * 64]);\
792 sum op MULS((w)[7 * 64], p[7 * 64]);\
795 #define SUM8P2(sum1, op1, sum2, op2, w1, w2, p) \
799 sum1 op1 MULS((w1)[0 * 64], tmp);\
800 sum2 op2 MULS((w2)[0 * 64], tmp);\
802 sum1 op1 MULS((w1)[1 * 64], tmp);\
803 sum2 op2 MULS((w2)[1 * 64], tmp);\
805 sum1 op1 MULS((w1)[2 * 64], tmp);\
806 sum2 op2 MULS((w2)[2 * 64], tmp);\
808 sum1 op1 MULS((w1)[3 * 64], tmp);\
809 sum2 op2 MULS((w2)[3 * 64], tmp);\
811 sum1 op1 MULS((w1)[4 * 64], tmp);\
812 sum2 op2 MULS((w2)[4 * 64], tmp);\
814 sum1 op1 MULS((w1)[5 * 64], tmp);\
815 sum2 op2 MULS((w2)[5 * 64], tmp);\
817 sum1 op1 MULS((w1)[6 * 64], tmp);\
818 sum2 op2 MULS((w2)[6 * 64], tmp);\
820 sum1 op1 MULS((w1)[7 * 64], tmp);\
821 sum2 op2 MULS((w2)[7 * 64], tmp);\
824 void ff_mpa_synth_init(MPA_INT *window)
828 /* max = 18760, max sum over all 16 coefs : 44736 */
833 v = (v + (1 << (16 - WFRAC_BITS - 1))) >> (16 - WFRAC_BITS);
843 /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:
845 /* XXX: optimize by avoiding ring buffer usage */
846 void ff_mpa_synth_filter(MPA_INT *synth_buf_ptr, int *synth_buf_offset,
847 MPA_INT *window, int *dither_state,
848 OUT_INT *samples, int incr,
849 int32_t sb_samples[SBLIMIT])
852 register MPA_INT *synth_buf;
853 register const MPA_INT *w, *w2, *p;
862 dct32(tmp, sb_samples);
864 offset = *synth_buf_offset;
865 synth_buf = synth_buf_ptr + offset;
870 /* NOTE: can cause a loss in precision if very high amplitude
879 /* copy to avoid wrap */
880 memcpy(synth_buf + 512, synth_buf, 32 * sizeof(MPA_INT));
882 samples2 = samples + 31 * incr;
890 SUM8(sum, -=, w + 32, p);
891 *samples = round_sample(&sum);
895 /* we calculate two samples at the same time to avoid one memory
896 access per two sample */
899 p = synth_buf + 16 + j;
900 SUM8P2(sum, +=, sum2, -=, w, w2, p);
901 p = synth_buf + 48 - j;
902 SUM8P2(sum, -=, sum2, -=, w + 32, w2 + 32, p);
904 *samples = round_sample(&sum);
907 *samples2 = round_sample(&sum);
914 SUM8(sum, -=, w + 32, p);
915 *samples = round_sample(&sum);
918 offset = (offset - 32) & 511;
919 *synth_buf_offset = offset;
922 #define C3 FIXHR(0.86602540378443864676/2)
924 /* 0.5 / cos(pi*(2*i+1)/36) */
925 static const int icos36[9] = {
926 FIXR(0.50190991877167369479),
927 FIXR(0.51763809020504152469), //0
928 FIXR(0.55168895948124587824),
929 FIXR(0.61038729438072803416),
930 FIXR(0.70710678118654752439), //1
931 FIXR(0.87172339781054900991),
932 FIXR(1.18310079157624925896),
933 FIXR(1.93185165257813657349), //2
934 FIXR(5.73685662283492756461),
937 /* 12 points IMDCT. We compute it "by hand" by factorizing obvious
939 static void imdct12(int *out, int *in)
941 int in0, in1, in2, in3, in4, in5, t1, t2;
944 in1= in[1*3] + in[0*3];
945 in2= in[2*3] + in[1*3];
946 in3= in[3*3] + in[2*3];
947 in4= in[4*3] + in[3*3];
948 in5= in[5*3] + in[4*3];
952 in2= MULH(2*in2, C3);
953 in3= MULH(2*in3, C3);
956 t2 = MULL(in1 - in5, icos36[4]);
966 in5 = MULL(in1 + in3, icos36[1]);
973 in1 = MULL(in1 - in3, icos36[7]);
981 #define C1 FIXHR(0.98480775301220805936/2)
982 #define C2 FIXHR(0.93969262078590838405/2)
983 #define C3 FIXHR(0.86602540378443864676/2)
984 #define C4 FIXHR(0.76604444311897803520/2)
985 #define C5 FIXHR(0.64278760968653932632/2)
986 #define C6 FIXHR(0.5/2)
987 #define C7 FIXHR(0.34202014332566873304/2)
988 #define C8 FIXHR(0.17364817766693034885/2)
991 /* using Lee like decomposition followed by hand coded 9 points DCT */
992 static void imdct36(int *out, int *buf, int *in, int *win)
994 int i, j, t0, t1, t2, t3, s0, s1, s2, s3;
995 int tmp[18], *tmp1, *in1;
1006 //more accurate but slower
1007 int64_t t0, t1, t2, t3;
1008 t2 = in1[2*4] + in1[2*8] - in1[2*2];
1010 t3 = (in1[2*0] + (int64_t)(in1[2*6]>>1))<<32;
1011 t1 = in1[2*0] - in1[2*6];
1012 tmp1[ 6] = t1 - (t2>>1);
1015 t0 = MUL64(2*(in1[2*2] + in1[2*4]), C2);
1016 t1 = MUL64( in1[2*4] - in1[2*8] , -2*C8);
1017 t2 = MUL64(2*(in1[2*2] + in1[2*8]), -C4);
1019 tmp1[10] = (t3 - t0 - t2) >> 32;
1020 tmp1[ 2] = (t3 + t0 + t1) >> 32;
1021 tmp1[14] = (t3 + t2 - t1) >> 32;
1023 tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);
1024 t2 = MUL64(2*(in1[2*1] + in1[2*5]), C1);
1025 t3 = MUL64( in1[2*5] - in1[2*7] , -2*C7);
1026 t0 = MUL64(2*in1[2*3], C3);
1028 t1 = MUL64(2*(in1[2*1] + in1[2*7]), -C5);
1030 tmp1[ 0] = (t2 + t3 + t0) >> 32;
1031 tmp1[12] = (t2 + t1 - t0) >> 32;
1032 tmp1[ 8] = (t3 - t1 - t0) >> 32;
1034 t2 = in1[2*4] + in1[2*8] - in1[2*2];
1036 t3 = in1[2*0] + (in1[2*6]>>1);
1037 t1 = in1[2*0] - in1[2*6];
1038 tmp1[ 6] = t1 - (t2>>1);
1041 t0 = MULH(2*(in1[2*2] + in1[2*4]), C2);
1042 t1 = MULH( in1[2*4] - in1[2*8] , -2*C8);
1043 t2 = MULH(2*(in1[2*2] + in1[2*8]), -C4);
1045 tmp1[10] = t3 - t0 - t2;
1046 tmp1[ 2] = t3 + t0 + t1;
1047 tmp1[14] = t3 + t2 - t1;
1049 tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);
1050 t2 = MULH(2*(in1[2*1] + in1[2*5]), C1);
1051 t3 = MULH( in1[2*5] - in1[2*7] , -2*C7);
1052 t0 = MULH(2*in1[2*3], C3);
1054 t1 = MULH(2*(in1[2*1] + in1[2*7]), -C5);
1056 tmp1[ 0] = t2 + t3 + t0;
1057 tmp1[12] = t2 + t1 - t0;
1058 tmp1[ 8] = t3 - t1 - t0;
1071 s1 = MULL(t3 + t2, icos36[j]);
1072 s3 = MULL(t3 - t2, icos36[8 - j]);
1076 out[(9 + j)*SBLIMIT] = MULH(t1, win[9 + j]) + buf[9 + j];
1077 out[(8 - j)*SBLIMIT] = MULH(t1, win[8 - j]) + buf[8 - j];
1078 buf[9 + j] = MULH(t0, win[18 + 9 + j]);
1079 buf[8 - j] = MULH(t0, win[18 + 8 - j]);
1083 out[(9 + 8 - j)*SBLIMIT] = MULH(t1, win[9 + 8 - j]) + buf[9 + 8 - j];
1084 out[( j)*SBLIMIT] = MULH(t1, win[ j]) + buf[ j];
1085 buf[9 + 8 - j] = MULH(t0, win[18 + 9 + 8 - j]);
1086 buf[ + j] = MULH(t0, win[18 + j]);
1091 s1 = MULL(tmp[17], icos36[4]);
1094 out[(9 + 4)*SBLIMIT] = MULH(t1, win[9 + 4]) + buf[9 + 4];
1095 out[(8 - 4)*SBLIMIT] = MULH(t1, win[8 - 4]) + buf[8 - 4];
1096 buf[9 + 4] = MULH(t0, win[18 + 9 + 4]);
1097 buf[8 - 4] = MULH(t0, win[18 + 8 - 4]);
1100 /* header decoding. MUST check the header before because no
1101 consistency check is done there. Return 1 if free format found and
1102 that the frame size must be computed externally */
1103 static int decode_header(MPADecodeContext *s, uint32_t header)
1105 int sample_rate, frame_size, mpeg25, padding;
1106 int sample_rate_index, bitrate_index;
1107 if (header & (1<<20)) {
1108 s->lsf = (header & (1<<19)) ? 0 : 1;
1115 s->layer = 4 - ((header >> 17) & 3);
1116 /* extract frequency */
1117 sample_rate_index = (header >> 10) & 3;
1118 sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);
1119 sample_rate_index += 3 * (s->lsf + mpeg25);
1120 s->sample_rate_index = sample_rate_index;
1121 s->error_protection = ((header >> 16) & 1) ^ 1;
1122 s->sample_rate = sample_rate;
1124 bitrate_index = (header >> 12) & 0xf;
1125 padding = (header >> 9) & 1;
1126 //extension = (header >> 8) & 1;
1127 s->mode = (header >> 6) & 3;
1128 s->mode_ext = (header >> 4) & 3;
1129 //copyright = (header >> 3) & 1;
1130 //original = (header >> 2) & 1;
1131 //emphasis = header & 3;
1133 if (s->mode == MPA_MONO)
1138 if (bitrate_index != 0) {
1139 frame_size = mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];
1140 s->bit_rate = frame_size * 1000;
1143 frame_size = (frame_size * 12000) / sample_rate;
1144 frame_size = (frame_size + padding) * 4;
1147 frame_size = (frame_size * 144000) / sample_rate;
1148 frame_size += padding;
1152 frame_size = (frame_size * 144000) / (sample_rate << s->lsf);
1153 frame_size += padding;
1156 s->frame_size = frame_size;
1158 /* if no frame size computed, signal it */
1159 if (!s->free_format_frame_size)
1161 /* free format: compute bitrate and real frame size from the
1162 frame size we extracted by reading the bitstream */
1163 s->frame_size = s->free_format_frame_size;
1166 s->frame_size += padding * 4;
1167 s->bit_rate = (s->frame_size * sample_rate) / 48000;
1170 s->frame_size += padding;
1171 s->bit_rate = (s->frame_size * sample_rate) / 144000;
1175 s->frame_size += padding;
1176 s->bit_rate = (s->frame_size * (sample_rate << s->lsf)) / 144000;
1182 printf("layer%d, %d Hz, %d kbits/s, ",
1183 s->layer, s->sample_rate, s->bit_rate);
1184 if (s->nb_channels == 2) {
1185 if (s->layer == 3) {
1186 if (s->mode_ext & MODE_EXT_MS_STEREO)
1188 if (s->mode_ext & MODE_EXT_I_STEREO)
1200 /* useful helper to get mpeg audio stream infos. Return -1 if error in
1201 header, otherwise the coded frame size in bytes */
1202 int mpa_decode_header(AVCodecContext *avctx, uint32_t head)
1204 MPADecodeContext s1, *s = &s1;
1205 memset( s, 0, sizeof(MPADecodeContext) );
1207 if (ff_mpa_check_header(head) != 0)
1210 if (decode_header(s, head) != 0) {
1216 avctx->frame_size = 384;
1219 avctx->frame_size = 1152;
1224 avctx->frame_size = 576;
1226 avctx->frame_size = 1152;
1230 avctx->sample_rate = s->sample_rate;
1231 avctx->channels = s->nb_channels;
1232 avctx->bit_rate = s->bit_rate;
1233 avctx->sub_id = s->layer;
1234 return s->frame_size;
1237 /* return the number of decoded frames */
1238 static int mp_decode_layer1(MPADecodeContext *s)
1240 int bound, i, v, n, ch, j, mant;
1241 uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
1242 uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
1244 if (s->mode == MPA_JSTEREO)
1245 bound = (s->mode_ext + 1) * 4;
1249 /* allocation bits */
1250 for(i=0;i<bound;i++) {
1251 for(ch=0;ch<s->nb_channels;ch++) {
1252 allocation[ch][i] = get_bits(&s->gb, 4);
1255 for(i=bound;i<SBLIMIT;i++) {
1256 allocation[0][i] = get_bits(&s->gb, 4);
1260 for(i=0;i<bound;i++) {
1261 for(ch=0;ch<s->nb_channels;ch++) {
1262 if (allocation[ch][i])
1263 scale_factors[ch][i] = get_bits(&s->gb, 6);
1266 for(i=bound;i<SBLIMIT;i++) {
1267 if (allocation[0][i]) {
1268 scale_factors[0][i] = get_bits(&s->gb, 6);
1269 scale_factors[1][i] = get_bits(&s->gb, 6);
1273 /* compute samples */
1275 for(i=0;i<bound;i++) {
1276 for(ch=0;ch<s->nb_channels;ch++) {
1277 n = allocation[ch][i];
1279 mant = get_bits(&s->gb, n + 1);
1280 v = l1_unscale(n, mant, scale_factors[ch][i]);
1284 s->sb_samples[ch][j][i] = v;
1287 for(i=bound;i<SBLIMIT;i++) {
1288 n = allocation[0][i];
1290 mant = get_bits(&s->gb, n + 1);
1291 v = l1_unscale(n, mant, scale_factors[0][i]);
1292 s->sb_samples[0][j][i] = v;
1293 v = l1_unscale(n, mant, scale_factors[1][i]);
1294 s->sb_samples[1][j][i] = v;
1296 s->sb_samples[0][j][i] = 0;
1297 s->sb_samples[1][j][i] = 0;
1304 /* bitrate is in kb/s */
1305 int l2_select_table(int bitrate, int nb_channels, int freq, int lsf)
1307 int ch_bitrate, table;
1309 ch_bitrate = bitrate / nb_channels;
1311 if ((freq == 48000 && ch_bitrate >= 56) ||
1312 (ch_bitrate >= 56 && ch_bitrate <= 80))
1314 else if (freq != 48000 && ch_bitrate >= 96)
1316 else if (freq != 32000 && ch_bitrate <= 48)
1326 static int mp_decode_layer2(MPADecodeContext *s)
1328 int sblimit; /* number of used subbands */
1329 const unsigned char *alloc_table;
1330 int table, bit_alloc_bits, i, j, ch, bound, v;
1331 unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
1332 unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
1333 unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
1334 int scale, qindex, bits, steps, k, l, m, b;
1336 /* select decoding table */
1337 table = l2_select_table(s->bit_rate / 1000, s->nb_channels,
1338 s->sample_rate, s->lsf);
1339 sblimit = sblimit_table[table];
1340 alloc_table = alloc_tables[table];
1342 if (s->mode == MPA_JSTEREO)
1343 bound = (s->mode_ext + 1) * 4;
1347 dprintf("bound=%d sblimit=%d\n", bound, sblimit);
1350 if( bound > sblimit ) bound = sblimit;
1352 /* parse bit allocation */
1354 for(i=0;i<bound;i++) {
1355 bit_alloc_bits = alloc_table[j];
1356 for(ch=0;ch<s->nb_channels;ch++) {
1357 bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
1359 j += 1 << bit_alloc_bits;
1361 for(i=bound;i<sblimit;i++) {
1362 bit_alloc_bits = alloc_table[j];
1363 v = get_bits(&s->gb, bit_alloc_bits);
1364 bit_alloc[0][i] = v;
1365 bit_alloc[1][i] = v;
1366 j += 1 << bit_alloc_bits;
1371 for(ch=0;ch<s->nb_channels;ch++) {
1372 for(i=0;i<sblimit;i++)
1373 printf(" %d", bit_alloc[ch][i]);
1380 for(i=0;i<sblimit;i++) {
1381 for(ch=0;ch<s->nb_channels;ch++) {
1382 if (bit_alloc[ch][i])
1383 scale_code[ch][i] = get_bits(&s->gb, 2);
1388 for(i=0;i<sblimit;i++) {
1389 for(ch=0;ch<s->nb_channels;ch++) {
1390 if (bit_alloc[ch][i]) {
1391 sf = scale_factors[ch][i];
1392 switch(scale_code[ch][i]) {
1395 sf[0] = get_bits(&s->gb, 6);
1396 sf[1] = get_bits(&s->gb, 6);
1397 sf[2] = get_bits(&s->gb, 6);
1400 sf[0] = get_bits(&s->gb, 6);
1405 sf[0] = get_bits(&s->gb, 6);
1406 sf[2] = get_bits(&s->gb, 6);
1410 sf[0] = get_bits(&s->gb, 6);
1411 sf[2] = get_bits(&s->gb, 6);
1420 for(ch=0;ch<s->nb_channels;ch++) {
1421 for(i=0;i<sblimit;i++) {
1422 if (bit_alloc[ch][i]) {
1423 sf = scale_factors[ch][i];
1424 printf(" %d %d %d", sf[0], sf[1], sf[2]);
1435 for(l=0;l<12;l+=3) {
1437 for(i=0;i<bound;i++) {
1438 bit_alloc_bits = alloc_table[j];
1439 for(ch=0;ch<s->nb_channels;ch++) {
1440 b = bit_alloc[ch][i];
1442 scale = scale_factors[ch][i][k];
1443 qindex = alloc_table[j+b];
1444 bits = quant_bits[qindex];
1446 /* 3 values at the same time */
1447 v = get_bits(&s->gb, -bits);
1448 steps = quant_steps[qindex];
1449 s->sb_samples[ch][k * 12 + l + 0][i] =
1450 l2_unscale_group(steps, v % steps, scale);
1452 s->sb_samples[ch][k * 12 + l + 1][i] =
1453 l2_unscale_group(steps, v % steps, scale);
1455 s->sb_samples[ch][k * 12 + l + 2][i] =
1456 l2_unscale_group(steps, v, scale);
1459 v = get_bits(&s->gb, bits);
1460 v = l1_unscale(bits - 1, v, scale);
1461 s->sb_samples[ch][k * 12 + l + m][i] = v;
1465 s->sb_samples[ch][k * 12 + l + 0][i] = 0;
1466 s->sb_samples[ch][k * 12 + l + 1][i] = 0;
1467 s->sb_samples[ch][k * 12 + l + 2][i] = 0;
1470 /* next subband in alloc table */
1471 j += 1 << bit_alloc_bits;
1473 /* XXX: find a way to avoid this duplication of code */
1474 for(i=bound;i<sblimit;i++) {
1475 bit_alloc_bits = alloc_table[j];
1476 b = bit_alloc[0][i];
1478 int mant, scale0, scale1;
1479 scale0 = scale_factors[0][i][k];
1480 scale1 = scale_factors[1][i][k];
1481 qindex = alloc_table[j+b];
1482 bits = quant_bits[qindex];
1484 /* 3 values at the same time */
1485 v = get_bits(&s->gb, -bits);
1486 steps = quant_steps[qindex];
1489 s->sb_samples[0][k * 12 + l + 0][i] =
1490 l2_unscale_group(steps, mant, scale0);
1491 s->sb_samples[1][k * 12 + l + 0][i] =
1492 l2_unscale_group(steps, mant, scale1);
1495 s->sb_samples[0][k * 12 + l + 1][i] =
1496 l2_unscale_group(steps, mant, scale0);
1497 s->sb_samples[1][k * 12 + l + 1][i] =
1498 l2_unscale_group(steps, mant, scale1);
1499 s->sb_samples[0][k * 12 + l + 2][i] =
1500 l2_unscale_group(steps, v, scale0);
1501 s->sb_samples[1][k * 12 + l + 2][i] =
1502 l2_unscale_group(steps, v, scale1);
1505 mant = get_bits(&s->gb, bits);
1506 s->sb_samples[0][k * 12 + l + m][i] =
1507 l1_unscale(bits - 1, mant, scale0);
1508 s->sb_samples[1][k * 12 + l + m][i] =
1509 l1_unscale(bits - 1, mant, scale1);
1513 s->sb_samples[0][k * 12 + l + 0][i] = 0;
1514 s->sb_samples[0][k * 12 + l + 1][i] = 0;
1515 s->sb_samples[0][k * 12 + l + 2][i] = 0;
1516 s->sb_samples[1][k * 12 + l + 0][i] = 0;
1517 s->sb_samples[1][k * 12 + l + 1][i] = 0;
1518 s->sb_samples[1][k * 12 + l + 2][i] = 0;
1520 /* next subband in alloc table */
1521 j += 1 << bit_alloc_bits;
1523 /* fill remaining samples to zero */
1524 for(i=sblimit;i<SBLIMIT;i++) {
1525 for(ch=0;ch<s->nb_channels;ch++) {
1526 s->sb_samples[ch][k * 12 + l + 0][i] = 0;
1527 s->sb_samples[ch][k * 12 + l + 1][i] = 0;
1528 s->sb_samples[ch][k * 12 + l + 2][i] = 0;
1537 * Seek back in the stream for backstep bytes (at most 511 bytes)
1539 static void seek_to_maindata(MPADecodeContext *s, unsigned int backstep)
1543 /* compute current position in stream */
1544 ptr = (uint8_t *)(s->gb.buffer + (get_bits_count(&s->gb)>>3));
1546 /* copy old data before current one */
1548 memcpy(ptr, s->inbuf1[s->inbuf_index ^ 1] +
1549 BACKSTEP_SIZE + s->old_frame_size - backstep, backstep);
1550 /* init get bits again */
1551 init_get_bits(&s->gb, ptr, (s->frame_size + backstep)*8);
1553 /* prepare next buffer */
1554 s->inbuf_index ^= 1;
1555 s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
1556 s->old_frame_size = s->frame_size;
1559 static inline void lsf_sf_expand(int *slen,
1560 int sf, int n1, int n2, int n3)
1579 static void exponents_from_scale_factors(MPADecodeContext *s,
1583 const uint8_t *bstab, *pretab;
1584 int len, i, j, k, l, v0, shift, gain, gains[3];
1587 exp_ptr = exponents;
1588 gain = g->global_gain - 210;
1589 shift = g->scalefac_scale + 1;
1591 bstab = band_size_long[s->sample_rate_index];
1592 pretab = mpa_pretab[g->preflag];
1593 for(i=0;i<g->long_end;i++) {
1594 v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift);
1600 if (g->short_start < 13) {
1601 bstab = band_size_short[s->sample_rate_index];
1602 gains[0] = gain - (g->subblock_gain[0] << 3);
1603 gains[1] = gain - (g->subblock_gain[1] << 3);
1604 gains[2] = gain - (g->subblock_gain[2] << 3);
1606 for(i=g->short_start;i<13;i++) {
1609 v0 = gains[l] - (g->scale_factors[k++] << shift);
1617 /* handle n = 0 too */
1618 static inline int get_bitsz(GetBitContext *s, int n)
1623 return get_bits(s, n);
1626 static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
1627 int16_t *exponents, int end_pos)
1630 int linbits, code, x, y, l, v, i, j, k, pos;
1631 GetBitContext last_gb;
1633 uint8_t *code_table;
1635 /* low frequencies (called big values) */
1638 j = g->region_size[i];
1641 /* select vlc table */
1642 k = g->table_select[i];
1643 l = mpa_huff_data[k][0];
1644 linbits = mpa_huff_data[k][1];
1646 code_table = huff_code_table[l];
1648 /* read huffcode and compute each couple */
1650 if (get_bits_count(&s->gb) >= end_pos)
1653 code = get_vlc(&s->gb, vlc);
1656 y = code_table[code];
1663 dprintf("region=%d n=%d x=%d y=%d exp=%d\n",
1664 i, g->region_size[i] - j, x, y, exponents[s_index]);
1667 x += get_bitsz(&s->gb, linbits);
1668 v = l3_unscale(x, exponents[s_index]);
1669 if (get_bits1(&s->gb))
1674 g->sb_hybrid[s_index++] = v;
1677 y += get_bitsz(&s->gb, linbits);
1678 v = l3_unscale(y, exponents[s_index]);
1679 if (get_bits1(&s->gb))
1684 g->sb_hybrid[s_index++] = v;
1688 /* high frequencies */
1689 vlc = &huff_quad_vlc[g->count1table_select];
1690 last_gb.buffer = NULL;
1691 while (s_index <= 572) {
1692 pos = get_bits_count(&s->gb);
1693 if (pos >= end_pos) {
1694 if (pos > end_pos && last_gb.buffer != NULL) {
1695 /* some encoders generate an incorrect size for this
1696 part. We must go back into the data */
1704 code = get_vlc(&s->gb, vlc);
1705 dprintf("t=%d code=%d\n", g->count1table_select, code);
1709 if (code & (8 >> i)) {
1710 /* non zero value. Could use a hand coded function for
1712 v = l3_unscale(1, exponents[s_index]);
1713 if(get_bits1(&s->gb))
1718 g->sb_hybrid[s_index++] = v;
1721 while (s_index < 576)
1722 g->sb_hybrid[s_index++] = 0;
1726 /* Reorder short blocks from bitstream order to interleaved order. It
1727 would be faster to do it in parsing, but the code would be far more
1729 static void reorder_block(MPADecodeContext *s, GranuleDef *g)
1732 int32_t *ptr, *dst, *ptr1;
1735 if (g->block_type != 2)
1738 if (g->switch_point) {
1739 if (s->sample_rate_index != 8) {
1740 ptr = g->sb_hybrid + 36;
1742 ptr = g->sb_hybrid + 48;
1748 for(i=g->short_start;i<13;i++) {
1749 len = band_size_short[s->sample_rate_index][i];
1753 for(j=len;j>0;j--) {
1758 memcpy(ptr1, tmp, len * 3 * sizeof(int32_t));
1762 #define ISQRT2 FIXR(0.70710678118654752440)
1764 static void compute_stereo(MPADecodeContext *s,
1765 GranuleDef *g0, GranuleDef *g1)
1769 int sf_max, tmp0, tmp1, sf, len, non_zero_found;
1770 int32_t (*is_tab)[16];
1771 int32_t *tab0, *tab1;
1772 int non_zero_found_short[3];
1774 /* intensity stereo */
1775 if (s->mode_ext & MODE_EXT_I_STEREO) {
1780 is_tab = is_table_lsf[g1->scalefac_compress & 1];
1784 tab0 = g0->sb_hybrid + 576;
1785 tab1 = g1->sb_hybrid + 576;
1787 non_zero_found_short[0] = 0;
1788 non_zero_found_short[1] = 0;
1789 non_zero_found_short[2] = 0;
1790 k = (13 - g1->short_start) * 3 + g1->long_end - 3;
1791 for(i = 12;i >= g1->short_start;i--) {
1792 /* for last band, use previous scale factor */
1795 len = band_size_short[s->sample_rate_index][i];
1799 if (!non_zero_found_short[l]) {
1800 /* test if non zero band. if so, stop doing i-stereo */
1801 for(j=0;j<len;j++) {
1803 non_zero_found_short[l] = 1;
1807 sf = g1->scale_factors[k + l];
1813 for(j=0;j<len;j++) {
1815 tab0[j] = MULL(tmp0, v1);
1816 tab1[j] = MULL(tmp0, v2);
1820 if (s->mode_ext & MODE_EXT_MS_STEREO) {
1821 /* lower part of the spectrum : do ms stereo
1823 for(j=0;j<len;j++) {
1826 tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
1827 tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
1834 non_zero_found = non_zero_found_short[0] |
1835 non_zero_found_short[1] |
1836 non_zero_found_short[2];
1838 for(i = g1->long_end - 1;i >= 0;i--) {
1839 len = band_size_long[s->sample_rate_index][i];
1842 /* test if non zero band. if so, stop doing i-stereo */
1843 if (!non_zero_found) {
1844 for(j=0;j<len;j++) {
1850 /* for last band, use previous scale factor */
1851 k = (i == 21) ? 20 : i;
1852 sf = g1->scale_factors[k];
1857 for(j=0;j<len;j++) {
1859 tab0[j] = MULL(tmp0, v1);
1860 tab1[j] = MULL(tmp0, v2);
1864 if (s->mode_ext & MODE_EXT_MS_STEREO) {
1865 /* lower part of the spectrum : do ms stereo
1867 for(j=0;j<len;j++) {
1870 tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
1871 tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
1876 } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
1877 /* ms stereo ONLY */
1878 /* NOTE: the 1/sqrt(2) normalization factor is included in the
1880 tab0 = g0->sb_hybrid;
1881 tab1 = g1->sb_hybrid;
1882 for(i=0;i<576;i++) {
1885 tab0[i] = tmp0 + tmp1;
1886 tab1[i] = tmp0 - tmp1;
1891 static void compute_antialias_integer(MPADecodeContext *s,
1897 /* we antialias only "long" bands */
1898 if (g->block_type == 2) {
1899 if (!g->switch_point)
1901 /* XXX: check this for 8000Hz case */
1907 ptr = g->sb_hybrid + 18;
1908 for(i = n;i > 0;i--) {
1909 int tmp0, tmp1, tmp2;
1910 csa = &csa_table[0][0];
1914 tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\
1915 ptr[-1-j] = 4*(tmp2 - MULH(tmp1, csa[2+4*j]));\
1916 ptr[ j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j]));
1931 static void compute_antialias_float(MPADecodeContext *s,
1937 /* we antialias only "long" bands */
1938 if (g->block_type == 2) {
1939 if (!g->switch_point)
1941 /* XXX: check this for 8000Hz case */
1947 ptr = g->sb_hybrid + 18;
1948 for(i = n;i > 0;i--) {
1950 float *csa = &csa_table_float[0][0];
1951 #define FLOAT_AA(j)\
1954 ptr[-1-j] = lrintf(tmp0 * csa[0+4*j] - tmp1 * csa[1+4*j]);\
1955 ptr[ j] = lrintf(tmp0 * csa[1+4*j] + tmp1 * csa[0+4*j]);
1970 static void compute_imdct(MPADecodeContext *s,
1972 int32_t *sb_samples,
1975 int32_t *ptr, *win, *win1, *buf, *out_ptr, *ptr1;
1977 int i, j, mdct_long_end, v, sblimit;
1979 /* find last non zero block */
1980 ptr = g->sb_hybrid + 576;
1981 ptr1 = g->sb_hybrid + 2 * 18;
1982 while (ptr >= ptr1) {
1984 v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];
1988 sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
1990 if (g->block_type == 2) {
1991 /* XXX: check for 8000 Hz */
1992 if (g->switch_point)
1997 mdct_long_end = sblimit;
2002 for(j=0;j<mdct_long_end;j++) {
2003 /* apply window & overlap with previous buffer */
2004 out_ptr = sb_samples + j;
2006 if (g->switch_point && j < 2)
2009 win1 = mdct_win[g->block_type];
2010 /* select frequency inversion */
2011 win = win1 + ((4 * 36) & -(j & 1));
2012 imdct36(out_ptr, buf, ptr, win);
2013 out_ptr += 18*SBLIMIT;
2017 for(j=mdct_long_end;j<sblimit;j++) {
2018 /* select frequency inversion */
2019 win = mdct_win[2] + ((4 * 36) & -(j & 1));
2020 out_ptr = sb_samples + j;
2026 imdct12(out2, ptr + 0);
2028 *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*1];
2029 buf[i + 6*2] = MULH(out2[i + 6], win[i + 6]);
2032 imdct12(out2, ptr + 1);
2034 *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*2];
2035 buf[i + 6*0] = MULH(out2[i + 6], win[i + 6]);
2038 imdct12(out2, ptr + 2);
2040 buf[i + 6*0] = MULH(out2[i], win[i]) + buf[i + 6*0];
2041 buf[i + 6*1] = MULH(out2[i + 6], win[i + 6]);
2048 for(j=sblimit;j<SBLIMIT;j++) {
2050 out_ptr = sb_samples + j;
2061 void sample_dump(int fnum, int32_t *tab, int n)
2063 static FILE *files[16], *f;
2070 snprintf(buf, sizeof(buf), "/tmp/out%d.%s.pcm",
2072 #ifdef USE_HIGHPRECISION
2078 f = fopen(buf, "w");
2086 av_log(NULL, AV_LOG_DEBUG, "pos=%d\n", pos);
2088 av_log(NULL, AV_LOG_DEBUG, " %0.4f", (double)tab[i] / FRAC_ONE);
2090 av_log(NULL, AV_LOG_DEBUG, "\n");
2095 /* normalize to 23 frac bits */
2096 v = tab[i] << (23 - FRAC_BITS);
2097 fwrite(&v, 1, sizeof(int32_t), f);
2103 /* main layer3 decoding function */
2104 static int mp_decode_layer3(MPADecodeContext *s)
2106 int nb_granules, main_data_begin, private_bits;
2107 int gr, ch, blocksplit_flag, i, j, k, n, bits_pos, bits_left;
2108 GranuleDef granules[2][2], *g;
2109 int16_t exponents[576];
2111 /* read side info */
2113 main_data_begin = get_bits(&s->gb, 8);
2114 if (s->nb_channels == 2)
2115 private_bits = get_bits(&s->gb, 2);
2117 private_bits = get_bits(&s->gb, 1);
2120 main_data_begin = get_bits(&s->gb, 9);
2121 if (s->nb_channels == 2)
2122 private_bits = get_bits(&s->gb, 3);
2124 private_bits = get_bits(&s->gb, 5);
2126 for(ch=0;ch<s->nb_channels;ch++) {
2127 granules[ch][0].scfsi = 0; /* all scale factors are transmitted */
2128 granules[ch][1].scfsi = get_bits(&s->gb, 4);
2132 for(gr=0;gr<nb_granules;gr++) {
2133 for(ch=0;ch<s->nb_channels;ch++) {
2134 dprintf("gr=%d ch=%d: side_info\n", gr, ch);
2135 g = &granules[ch][gr];
2136 g->part2_3_length = get_bits(&s->gb, 12);
2137 g->big_values = get_bits(&s->gb, 9);
2138 g->global_gain = get_bits(&s->gb, 8);
2139 /* if MS stereo only is selected, we precompute the
2140 1/sqrt(2) renormalization factor */
2141 if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
2143 g->global_gain -= 2;
2145 g->scalefac_compress = get_bits(&s->gb, 9);
2147 g->scalefac_compress = get_bits(&s->gb, 4);
2148 blocksplit_flag = get_bits(&s->gb, 1);
2149 if (blocksplit_flag) {
2150 g->block_type = get_bits(&s->gb, 2);
2151 if (g->block_type == 0)
2153 g->switch_point = get_bits(&s->gb, 1);
2155 g->table_select[i] = get_bits(&s->gb, 5);
2157 g->subblock_gain[i] = get_bits(&s->gb, 3);
2158 /* compute huffman coded region sizes */
2159 if (g->block_type == 2)
2160 g->region_size[0] = (36 / 2);
2162 if (s->sample_rate_index <= 2)
2163 g->region_size[0] = (36 / 2);
2164 else if (s->sample_rate_index != 8)
2165 g->region_size[0] = (54 / 2);
2167 g->region_size[0] = (108 / 2);
2169 g->region_size[1] = (576 / 2);
2171 int region_address1, region_address2, l;
2173 g->switch_point = 0;
2175 g->table_select[i] = get_bits(&s->gb, 5);
2176 /* compute huffman coded region sizes */
2177 region_address1 = get_bits(&s->gb, 4);
2178 region_address2 = get_bits(&s->gb, 3);
2179 dprintf("region1=%d region2=%d\n",
2180 region_address1, region_address2);
2182 band_index_long[s->sample_rate_index][region_address1 + 1] >> 1;
2183 l = region_address1 + region_address2 + 2;
2184 /* should not overflow */
2188 band_index_long[s->sample_rate_index][l] >> 1;
2190 /* convert region offsets to region sizes and truncate
2191 size to big_values */
2192 g->region_size[2] = (576 / 2);
2195 k = g->region_size[i];
2196 if (k > g->big_values)
2198 g->region_size[i] = k - j;
2202 /* compute band indexes */
2203 if (g->block_type == 2) {
2204 if (g->switch_point) {
2205 /* if switched mode, we handle the 36 first samples as
2206 long blocks. For 8000Hz, we handle the 48 first
2207 exponents as long blocks (XXX: check this!) */
2208 if (s->sample_rate_index <= 2)
2210 else if (s->sample_rate_index != 8)
2213 g->long_end = 4; /* 8000 Hz */
2215 if (s->sample_rate_index != 8)
2224 g->short_start = 13;
2230 g->preflag = get_bits(&s->gb, 1);
2231 g->scalefac_scale = get_bits(&s->gb, 1);
2232 g->count1table_select = get_bits(&s->gb, 1);
2233 dprintf("block_type=%d switch_point=%d\n",
2234 g->block_type, g->switch_point);
2239 /* now we get bits from the main_data_begin offset */
2240 dprintf("seekback: %d\n", main_data_begin);
2241 seek_to_maindata(s, main_data_begin);
2244 for(gr=0;gr<nb_granules;gr++) {
2245 for(ch=0;ch<s->nb_channels;ch++) {
2246 g = &granules[ch][gr];
2248 bits_pos = get_bits_count(&s->gb);
2252 int slen, slen1, slen2;
2254 /* MPEG1 scale factors */
2255 slen1 = slen_table[0][g->scalefac_compress];
2256 slen2 = slen_table[1][g->scalefac_compress];
2257 dprintf("slen1=%d slen2=%d\n", slen1, slen2);
2258 if (g->block_type == 2) {
2259 n = g->switch_point ? 17 : 18;
2262 g->scale_factors[j++] = get_bitsz(&s->gb, slen1);
2264 g->scale_factors[j++] = get_bitsz(&s->gb, slen2);
2266 g->scale_factors[j++] = 0;
2268 sc = granules[ch][0].scale_factors;
2271 n = (k == 0 ? 6 : 5);
2272 if ((g->scfsi & (0x8 >> k)) == 0) {
2273 slen = (k < 2) ? slen1 : slen2;
2275 g->scale_factors[j++] = get_bitsz(&s->gb, slen);
2277 /* simply copy from last granule */
2279 g->scale_factors[j] = sc[j];
2284 g->scale_factors[j++] = 0;
2288 printf("scfsi=%x gr=%d ch=%d scale_factors:\n",
2291 printf(" %d", g->scale_factors[i]);
2296 int tindex, tindex2, slen[4], sl, sf;
2298 /* LSF scale factors */
2299 if (g->block_type == 2) {
2300 tindex = g->switch_point ? 2 : 1;
2304 sf = g->scalefac_compress;
2305 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
2306 /* intensity stereo case */
2309 lsf_sf_expand(slen, sf, 6, 6, 0);
2311 } else if (sf < 244) {
2312 lsf_sf_expand(slen, sf - 180, 4, 4, 0);
2315 lsf_sf_expand(slen, sf - 244, 3, 0, 0);
2321 lsf_sf_expand(slen, sf, 5, 4, 4);
2323 } else if (sf < 500) {
2324 lsf_sf_expand(slen, sf - 400, 5, 4, 0);
2327 lsf_sf_expand(slen, sf - 500, 3, 0, 0);
2335 n = lsf_nsf_table[tindex2][tindex][k];
2338 g->scale_factors[j++] = get_bitsz(&s->gb, sl);
2340 /* XXX: should compute exact size */
2342 g->scale_factors[j] = 0;
2345 printf("gr=%d ch=%d scale_factors:\n",
2348 printf(" %d", g->scale_factors[i]);
2354 exponents_from_scale_factors(s, g, exponents);
2356 /* read Huffman coded residue */
2357 if (huffman_decode(s, g, exponents,
2358 bits_pos + g->part2_3_length) < 0)
2361 sample_dump(0, g->sb_hybrid, 576);
2364 /* skip extension bits */
2365 bits_left = g->part2_3_length - (get_bits_count(&s->gb) - bits_pos);
2366 if (bits_left < 0) {
2367 dprintf("bits_left=%d\n", bits_left);
2370 while (bits_left >= 16) {
2371 skip_bits(&s->gb, 16);
2375 skip_bits(&s->gb, bits_left);
2378 if (s->nb_channels == 2)
2379 compute_stereo(s, &granules[0][gr], &granules[1][gr]);
2381 for(ch=0;ch<s->nb_channels;ch++) {
2382 g = &granules[ch][gr];
2384 reorder_block(s, g);
2386 sample_dump(0, g->sb_hybrid, 576);
2388 s->compute_antialias(s, g);
2390 sample_dump(1, g->sb_hybrid, 576);
2392 compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
2394 sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);
2398 return nb_granules * 18;
2401 static int mp_decode_frame(MPADecodeContext *s,
2404 int i, nb_frames, ch;
2405 OUT_INT *samples_ptr;
2407 init_get_bits(&s->gb, s->inbuf + HEADER_SIZE,
2408 (s->inbuf_ptr - s->inbuf - HEADER_SIZE)*8);
2410 /* skip error protection field */
2411 if (s->error_protection)
2412 get_bits(&s->gb, 16);
2414 dprintf("frame %d:\n", s->frame_count);
2417 nb_frames = mp_decode_layer1(s);
2420 nb_frames = mp_decode_layer2(s);
2424 nb_frames = mp_decode_layer3(s);
2428 for(i=0;i<nb_frames;i++) {
2429 for(ch=0;ch<s->nb_channels;ch++) {
2431 printf("%d-%d:", i, ch);
2432 for(j=0;j<SBLIMIT;j++)
2433 printf(" %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);
2438 /* apply the synthesis filter */
2439 for(ch=0;ch<s->nb_channels;ch++) {
2440 samples_ptr = samples + ch;
2441 for(i=0;i<nb_frames;i++) {
2442 ff_mpa_synth_filter(s->synth_buf[ch], &(s->synth_buf_offset[ch]),
2443 window, &s->dither_state,
2444 samples_ptr, s->nb_channels,
2445 s->sb_samples[ch][i]);
2446 samples_ptr += 32 * s->nb_channels;
2452 return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;
2455 static int decode_frame(AVCodecContext * avctx,
2456 void *data, int *data_size,
2457 uint8_t * buf, int buf_size)
2459 MPADecodeContext *s = avctx->priv_data;
2463 OUT_INT *out_samples = data;
2466 while (buf_size > 0) {
2467 len = s->inbuf_ptr - s->inbuf;
2468 if (s->frame_size == 0) {
2469 /* special case for next header for first frame in free
2470 format case (XXX: find a simpler method) */
2471 if (s->free_format_next_header != 0) {
2472 s->inbuf[0] = s->free_format_next_header >> 24;
2473 s->inbuf[1] = s->free_format_next_header >> 16;
2474 s->inbuf[2] = s->free_format_next_header >> 8;
2475 s->inbuf[3] = s->free_format_next_header;
2476 s->inbuf_ptr = s->inbuf + 4;
2477 s->free_format_next_header = 0;
2480 /* no header seen : find one. We need at least HEADER_SIZE
2481 bytes to parse it */
2482 len = HEADER_SIZE - len;
2486 memcpy(s->inbuf_ptr, buf_ptr, len);
2489 s->inbuf_ptr += len;
2491 if ((s->inbuf_ptr - s->inbuf) >= HEADER_SIZE) {
2493 header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
2494 (s->inbuf[2] << 8) | s->inbuf[3];
2496 if (ff_mpa_check_header(header) < 0) {
2497 /* no sync found : move by one byte (inefficient, but simple!) */
2498 memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
2500 dprintf("skip %x\n", header);
2501 /* reset free format frame size to give a chance
2502 to get a new bitrate */
2503 s->free_format_frame_size = 0;
2505 if (decode_header(s, header) == 1) {
2506 /* free format: prepare to compute frame size */
2509 /* update codec info */
2510 avctx->sample_rate = s->sample_rate;
2511 avctx->channels = s->nb_channels;
2512 avctx->bit_rate = s->bit_rate;
2513 avctx->sub_id = s->layer;
2516 avctx->frame_size = 384;
2519 avctx->frame_size = 1152;
2523 avctx->frame_size = 576;
2525 avctx->frame_size = 1152;
2530 } else if (s->frame_size == -1) {
2531 /* free format : find next sync to compute frame size */
2532 len = MPA_MAX_CODED_FRAME_SIZE - len;
2536 /* frame too long: resync */
2538 memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
2545 memcpy(s->inbuf_ptr, buf_ptr, len);
2546 /* check for header */
2547 p = s->inbuf_ptr - 3;
2548 pend = s->inbuf_ptr + len - 4;
2550 header = (p[0] << 24) | (p[1] << 16) |
2552 header1 = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
2553 (s->inbuf[2] << 8) | s->inbuf[3];
2554 /* check with high probability that we have a
2556 if ((header & SAME_HEADER_MASK) ==
2557 (header1 & SAME_HEADER_MASK)) {
2558 /* header found: update pointers */
2559 len = (p + 4) - s->inbuf_ptr;
2563 /* compute frame size */
2564 s->free_format_next_header = header;
2565 s->free_format_frame_size = s->inbuf_ptr - s->inbuf;
2566 padding = (header1 >> 9) & 1;
2568 s->free_format_frame_size -= padding * 4;
2570 s->free_format_frame_size -= padding;
2571 dprintf("free frame size=%d padding=%d\n",
2572 s->free_format_frame_size, padding);
2573 decode_header(s, header1);
2578 /* not found: simply increase pointers */
2580 s->inbuf_ptr += len;
2583 } else if (len < s->frame_size) {
2584 if (s->frame_size > MPA_MAX_CODED_FRAME_SIZE)
2585 s->frame_size = MPA_MAX_CODED_FRAME_SIZE;
2586 len = s->frame_size - len;
2589 memcpy(s->inbuf_ptr, buf_ptr, len);
2591 s->inbuf_ptr += len;
2595 if (s->frame_size > 0 &&
2596 (s->inbuf_ptr - s->inbuf) >= s->frame_size) {
2597 if (avctx->parse_only) {
2598 /* simply return the frame data */
2599 *(uint8_t **)data = s->inbuf;
2600 out_size = s->inbuf_ptr - s->inbuf;
2602 out_size = mp_decode_frame(s, out_samples);
2604 s->inbuf_ptr = s->inbuf;
2607 *data_size = out_size;
2609 av_log(avctx, AV_LOG_DEBUG, "Error while decoding mpeg audio frame\n"); //FIXME return -1 / but also return the number of bytes consumed
2613 return buf_ptr - buf;
2617 static int decode_frame_adu(AVCodecContext * avctx,
2618 void *data, int *data_size,
2619 uint8_t * buf, int buf_size)
2621 MPADecodeContext *s = avctx->priv_data;
2624 OUT_INT *out_samples = data;
2628 // Discard too short frames
2629 if (buf_size < HEADER_SIZE) {
2635 if (len > MPA_MAX_CODED_FRAME_SIZE)
2636 len = MPA_MAX_CODED_FRAME_SIZE;
2638 memcpy(s->inbuf, buf, len);
2639 s->inbuf_ptr = s->inbuf + len;
2641 // Get header and restore sync word
2642 header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
2643 (s->inbuf[2] << 8) | s->inbuf[3] | 0xffe00000;
2645 if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame
2650 decode_header(s, header);
2651 /* update codec info */
2652 avctx->sample_rate = s->sample_rate;
2653 avctx->channels = s->nb_channels;
2654 avctx->bit_rate = s->bit_rate;
2655 avctx->sub_id = s->layer;
2657 avctx->frame_size=s->frame_size = len;
2659 if (avctx->parse_only) {
2660 /* simply return the frame data */
2661 *(uint8_t **)data = s->inbuf;
2662 out_size = s->inbuf_ptr - s->inbuf;
2664 out_size = mp_decode_frame(s, out_samples);
2667 *data_size = out_size;
2672 /* Next 3 arrays are indexed by channel config number (passed via codecdata) */
2673 static int mp3Frames[16] = {0,1,1,2,3,3,4,5,2}; /* number of mp3 decoder instances */
2674 static int mp3Channels[16] = {0,1,2,3,4,5,6,8,4}; /* total output channels */
2675 /* offsets into output buffer, assume output order is FL FR BL BR C LFE */
2676 static int chan_offset[9][5] = {
2681 {2,0,3}, // C FLR BS
2682 {4,0,2}, // C FLR BLRS
2683 {4,0,2,5}, // C FLR BLRS LFE
2684 {4,0,2,6,5}, // C FLR BLRS BLR LFE
2689 static int decode_init_mp3on4(AVCodecContext * avctx)
2691 MP3On4DecodeContext *s = avctx->priv_data;
2694 if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {
2695 av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");
2699 s->chan_cfg = (((unsigned char *)avctx->extradata)[1] >> 3) & 0x0f;
2700 s->frames = mp3Frames[s->chan_cfg];
2702 av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");
2705 avctx->channels = mp3Channels[s->chan_cfg];
2707 /* Init the first mp3 decoder in standard way, so that all tables get builded
2708 * We replace avctx->priv_data with the context of the first decoder so that
2709 * decode_init() does not have to be changed.
2710 * Other decoders will be inited here copying data from the first context
2712 // Allocate zeroed memory for the first decoder context
2713 s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));
2714 // Put decoder context in place to make init_decode() happy
2715 avctx->priv_data = s->mp3decctx[0];
2717 // Restore mp3on4 context pointer
2718 avctx->priv_data = s;
2719 s->mp3decctx[0]->adu_mode = 1; // Set adu mode
2721 /* Create a separate codec/context for each frame (first is already ok).
2722 * Each frame is 1 or 2 channels - up to 5 frames allowed
2724 for (i = 1; i < s->frames; i++) {
2725 s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));
2726 s->mp3decctx[i]->compute_antialias = s->mp3decctx[0]->compute_antialias;
2727 s->mp3decctx[i]->inbuf = &s->mp3decctx[i]->inbuf1[0][BACKSTEP_SIZE];
2728 s->mp3decctx[i]->inbuf_ptr = s->mp3decctx[i]->inbuf;
2729 s->mp3decctx[i]->adu_mode = 1;
2736 static int decode_close_mp3on4(AVCodecContext * avctx)
2738 MP3On4DecodeContext *s = avctx->priv_data;
2741 for (i = 0; i < s->frames; i++)
2742 if (s->mp3decctx[i])
2743 av_free(s->mp3decctx[i]);
2749 static int decode_frame_mp3on4(AVCodecContext * avctx,
2750 void *data, int *data_size,
2751 uint8_t * buf, int buf_size)
2753 MP3On4DecodeContext *s = avctx->priv_data;
2754 MPADecodeContext *m;
2755 int len, out_size = 0;
2757 OUT_INT *out_samples = data;
2758 OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS];
2759 OUT_INT *outptr, *bp;
2761 unsigned char *start2 = buf, *start;
2763 int off = avctx->channels;
2764 int *coff = chan_offset[s->chan_cfg];
2768 // Discard too short frames
2769 if (buf_size < HEADER_SIZE) {
2774 // If only one decoder interleave is not needed
2775 outptr = s->frames == 1 ? out_samples : decoded_buf;
2777 for (fr = 0; fr < s->frames; fr++) {
2779 fsize = (start[0] << 4) | (start[1] >> 4);
2784 if (fsize > MPA_MAX_CODED_FRAME_SIZE)
2785 fsize = MPA_MAX_CODED_FRAME_SIZE;
2786 m = s->mp3decctx[fr];
2788 /* copy original to new */
2789 m->inbuf_ptr = m->inbuf + fsize;
2790 memcpy(m->inbuf, start, fsize);
2793 header = (m->inbuf[0] << 24) | (m->inbuf[1] << 16) |
2794 (m->inbuf[2] << 8) | m->inbuf[3] | 0xfff00000;
2796 if (ff_mpa_check_header(header) < 0) { // Bad header, discard block
2801 decode_header(m, header);
2802 mp_decode_frame(m, decoded_buf);
2804 n = MPA_FRAME_SIZE * m->nb_channels;
2805 out_size += n * sizeof(OUT_INT);
2807 /* interleave output data */
2808 bp = out_samples + coff[fr];
2809 if(m->nb_channels == 1) {
2810 for(j = 0; j < n; j++) {
2811 *bp = decoded_buf[j];
2815 for(j = 0; j < n; j++) {
2816 bp[0] = decoded_buf[j++];
2817 bp[1] = decoded_buf[j];
2824 /* update codec info */
2825 avctx->sample_rate = s->mp3decctx[0]->sample_rate;
2826 avctx->frame_size= buf_size;
2827 avctx->bit_rate = 0;
2828 for (i = 0; i < s->frames; i++)
2829 avctx->bit_rate += s->mp3decctx[i]->bit_rate;
2831 *data_size = out_size;
2836 AVCodec mp2_decoder =
2841 sizeof(MPADecodeContext),
2846 CODEC_CAP_PARSE_ONLY,
2849 AVCodec mp3_decoder =
2854 sizeof(MPADecodeContext),
2859 CODEC_CAP_PARSE_ONLY,
2862 AVCodec mp3adu_decoder =
2867 sizeof(MPADecodeContext),
2872 CODEC_CAP_PARSE_ONLY,
2875 AVCodec mp3on4_decoder =
2880 sizeof(MP3On4DecodeContext),
2883 decode_close_mp3on4,
2884 decode_frame_mp3on4,