Skip to content

F
ffmpeg.wasm-core
Commit 239c2f4c authored by Fabrice Bellard's avatar Fabrice Bellard
Browse files
Options

added completely new mpeg audio decoder (integer only, free format support,... 

added completely new mpeg audio decoder (integer only, free format support, lsf/mpeg25 support, high/low precision support, simpler code)


Originally committed as revision 117 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent c8fbc22d
Hide whitespace changes
Inline Side-by-side
Showing with 2208 additions and 120 deletions
libavcodec/mpegaudiodec.c
View file @ 239c2f4c
......@@ -16,76 +16,934 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
//#define DEBUG
#include "avcodec.h"
#include "mpglib/mpg123.h"
#include <math.h>
#include "mpegaudio.h"
/*
* TODO:
* - add free format
* - do not rely anymore on mpglib (first step: implement dct64 and decoding filter)
* TODO:
* - in low precision mode, use more 16 bit multiplies in synth filter
* - test lsf / mpeg25 extensively.
*/
/* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
audio decoder */
//#define USE_HIGHPRECISION
#ifdef USE_HIGHPRECISION
#define FRAC_BITS 23 /* fractional bits for sb_samples and dct */
#define WFRAC_BITS 16 /* fractional bits for window */
#else
#define FRAC_BITS 15 /* fractional bits for sb_samples and dct */
#define WFRAC_BITS 14 /* fractional bits for window */
#endif
#define FRAC_ONE (1 << FRAC_BITS)
#define MULL(a,b) (((INT64)(a) * (INT64)(b)) >> FRAC_BITS)
#define MUL64(a,b) ((INT64)(a) * (INT64)(b))
#define FIX(a) ((int)((a) * FRAC_ONE))
/* WARNING: only correct for posititive numbers */
#define FIXR(a) ((int)((a) * FRAC_ONE + 0.5))
#define FRAC_RND(a) (((a) + (FRAC_ONE/2)) >> FRAC_BITS)
#if FRAC_BITS <= 15
typedef INT16 MPA_INT;
#else
typedef INT32 MPA_INT;
#endif
/****************/
#define HEADER_SIZE 4
#define BACKSTEP_SIZE 512
typedef struct MPADecodeContext {
struct mpstr mpstr;
UINT8 inbuf1[2][MAXFRAMESIZE + BACKSTEP_SIZE]; /* input buffer */
UINT8 inbuf1[2][MPA_MAX_CODED_FRAME_SIZE + BACKSTEP_SIZE]; /* input buffer */
int inbuf_index;
UINT8 *inbuf_ptr, *inbuf;
int frame_size;
int free_format_frame_size; /* frame size in case of free format
(zero if currently unknown) */
/* next header (used in free format parsing) */
UINT32 free_format_next_header;
int error_protection;
int layer;
int sample_rate;
int sample_rate_index; /* between 0 and 8 */
int bit_rate;
int old_frame_size;
GetBitContext gb;
int nb_channels;
int mode;
int mode_ext;
int lsf;
MPA_INT synth_buf[MPA_MAX_CHANNELS][512 * 2];
int synth_buf_offset[MPA_MAX_CHANNELS];
INT32 sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT];
INT32 mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
#ifdef DEBUG
int frame_count;
#endif
} MPADecodeContext;
/* XXX: suppress that mess */
struct mpstr *gmp;
GetBitContext *gmp_gb;
static MPADecodeContext *gmp_s;
/* layer 3 "granule" */
typedef struct GranuleDef {
UINT8 scfsi;
int part2_3_length;
int big_values;
int global_gain;
int scalefac_compress;
UINT8 block_type;
UINT8 switch_point;
int table_select[3];
int subblock_gain[3];
UINT8 scalefac_scale;
UINT8 count1table_select;
int region_size[3]; /* number of huffman codes in each region */
int preflag;
int short_start, long_end; /* long/short band indexes */
UINT8 scale_factors[40];
INT32 sb_hybrid[SBLIMIT * 18]; /* 576 samples */
} GranuleDef;
/* XXX: merge constants with encoder */
static const unsigned short mp_bitrate_tab[2][3][15] = {
{ {0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448 },
{0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384 },
{0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320 } },
{ {0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256},
{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160},
{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160}
}
#define MODE_EXT_MS_STEREO 2
#define MODE_EXT_I_STEREO 1
/* layer 3 huffman tables */
typedef struct HuffTable {
int xsize;
const UINT8 *bits;
const UINT16 *codes;
} HuffTable;
#include "mpegaudiodectab.h"
/* vlc structure for decoding layer 3 huffman tables */
static VLC huff_vlc[16];
static UINT8 *huff_code_table[16];
static VLC huff_quad_vlc[2];
/* computed from band_size_long */
static UINT16 band_index_long[9][23];
/* XXX: free when all decoders are closed */
#define TABLE_4_3_SIZE (8191 + 16)
static UINT8 *table_4_3_exp;
#if FRAC_BITS <= 15
static UINT16 *table_4_3_value;
#else
static UINT32 *table_4_3_value;
#endif
/* intensity stereo coef table */
static INT32 is_table[2][16];
static INT32 is_table_lsf[2][2][16];
static INT32 csa_table[8][2];
static INT32 mdct_win[8][36];
/* lower 2 bits: modulo 3, higher bits: shift */
static UINT16 scale_factor_modshift[64];
/* [i][j]: 2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
static INT32 scale_factor_mult[15][3];
/* mult table for layer 2 group quantization */
#define SCALE_GEN(v) \
{ FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) }
static INT32 scale_factor_mult2[3][3] = {
SCALE_GEN(1.0 / 3.0), /* 3 steps */
SCALE_GEN(1.0 / 5.0), /* 5 steps */
SCALE_GEN(1.0 / 9.0), /* 9 steps */
};
/* 2^(n/4) */
static UINT32 scale_factor_mult3[4] = {
FIXR(1.0),
FIXR(1.18920711500272106671),
FIXR(1.41421356237309504880),
FIXR(1.68179283050742908605),
};
static unsigned short mp_freq_tab[3] = { 44100, 48000, 32000 };
static MPA_INT window[512];
/* layer 1 unscaling */
/* n = number of bits of the mantissa minus 1 */
static inline int l1_unscale(int n, int mant, int scale_factor)
{
int shift, mod;
INT64 val;
shift = scale_factor_modshift[scale_factor];
mod = shift & 3;
shift >>= 2;
val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
shift += n;
return (int)((val + (1 << (shift - 1))) >> shift);
}
static inline int l2_unscale_group(int steps, int mant, int scale_factor)
{
int shift, mod, val;
shift = scale_factor_modshift[scale_factor];
mod = shift & 3;
shift >>= 2;
/* XXX: store the result directly */
val = (2 * (mant - (steps >> 1))) * scale_factor_mult2[steps >> 2][mod];
return (val + (1 << (shift - 1))) >> shift;
}
/* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
static inline int l3_unscale(int value, int exponent)
{
#if FRAC_BITS <= 15
unsigned int m;
#else
UINT64 m;
#endif
int e;
e = table_4_3_exp[value];
e += (exponent >> 2);
e = FRAC_BITS - e;
#if FRAC_BITS <= 15
if (e > 31)
e = 31;
#endif
m = table_4_3_value[value];
#if FRAC_BITS <= 15
m = (m * scale_factor_mult3[exponent & 3]);
m = (m + (1 << (e-1))) >> e;
return m;
#else
m = MUL64(m, scale_factor_mult3[exponent & 3]);
m = (m + (UINT64_C(1) << (e-1))) >> e;
return m;
#endif
}
static int decode_init(AVCodecContext * avctx)
{
MPADecodeContext *s = avctx->priv_data;
struct mpstr *mp = &s->mpstr;
static int init;
mp->fr.single = -1;
mp->synth_bo = 1;
int i, j, k;
if(!init) {
/* scale factors table for layer 1/2 */
for(i=0;i<64;i++) {
int shift, mod;
/* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
shift = (i / 3) - 1;
mod = i % 3;
#if FRAC_BITS <= 15
if (shift > 31)
shift = 31;
#endif
scale_factor_modshift[i] = mod | (shift << 2);
}
/* scale factor multiply for layer 1 */
for(i=0;i<15;i++) {
int n, norm;
n = i + 2;
norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
scale_factor_mult[i][0] = MULL(FIXR(1.0), norm);
scale_factor_mult[i][1] = MULL(FIXR(0.7937005259), norm);
scale_factor_mult[i][2] = MULL(FIXR(0.6299605249), norm);
dprintf("%d: norm=%x s=%x %x %x\n",
i, norm,
scale_factor_mult[i][0],
scale_factor_mult[i][1],
scale_factor_mult[i][2]);
}
/* window */
/* max = 18760, max sum over all 16 coefs : 44736 */
for(i=0;i<257;i++) {
int v;
v = mpa_enwindow[i];
#if WFRAC_BITS < 16
v = (v + (1 << (16 - WFRAC_BITS - 1))) >> (16 - WFRAC_BITS);
#endif
window[i] = v;
if ((i & 63) != 0)
v = -v;
if (i != 0)
window[512 - i] = v;
}
/* huffman decode tables */
huff_code_table[0] = NULL;
for(i=1;i<16;i++) {
const HuffTable *h = &mpa_huff_tables[i];
int xsize, n, x, y;
UINT8 *code_table;
xsize = h->xsize;
n = xsize * xsize;
/* XXX: fail test */
init_vlc(&huff_vlc[i], 8, n,
h->bits, 1, 1, h->codes, 2, 2);
code_table = av_mallocz(n);
j = 0;
for(x=0;x<xsize;x++) {
for(y=0;y<xsize;y++)
code_table[j++] = (x << 4) | y;
}
huff_code_table[i] = code_table;
}
for(i=0;i<2;i++) {
init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1);
}
for(i=0;i<9;i++) {
k = 0;
for(j=0;j<22;j++) {
band_index_long[i][j] = k;
k += band_size_long[i][j];
}
band_index_long[i][22] = k;
}
/* compute n ^ (4/3) and store it in mantissa/exp format */
table_4_3_exp = av_mallocz(TABLE_4_3_SIZE *
sizeof(table_4_3_exp[0]));
if (!table_4_3_exp)
return -1;
table_4_3_value = av_mallocz(TABLE_4_3_SIZE *
sizeof(table_4_3_value[0]));
if (!table_4_3_value) {
free(table_4_3_exp);
return -1;
}
for(i=1;i<TABLE_4_3_SIZE;i++) {
double f, fm;
int e, m;
f = pow((double)i, 4.0 / 3.0);
fm = frexp(f, &e);
m = FIXR(2 * fm);
#if FRAC_BITS <= 15
if ((unsigned short)m != m)
m = 65535;
#endif
/* normalized to FRAC_BITS */
table_4_3_value[i] = m;
table_4_3_exp[i] = e - 1;
}
for(i=0;i<7;i++) {
float f;
int v;
if (i != 6) {
f = tan((double)i * M_PI / 12.0);
v = FIXR(f / (1.0 + f));
} else {
v = FIXR(1.0);
}
is_table[0][i] = v;
is_table[1][6 - i] = v;
}
/* invalid values */
for(i=7;i<16;i++)
is_table[0][i] = is_table[1][i] = 0.0;
for(i=0;i<16;i++) {
double f;
int e, k;
for(j=0;j<2;j++) {
e = -(j + 1) * ((i + 1) >> 1);
f = pow(2.0, e / 4.0);
k = i & 1;
is_table_lsf[j][k ^ 1][i] = FIXR(f);
is_table_lsf[j][k][i] = FIXR(1.0);
dprintf("is_table_lsf %d %d: %x %x\n",
i, j, is_table_lsf[j][0][i], is_table_lsf[j][1][i]);
}
}
for(i=0;i<8;i++) {
float ci, cs, ca;
ci = ci_table[i];
cs = 1.0 / sqrt(1.0 + ci * ci);
ca = cs * ci;
csa_table[i][0] = FIX(cs);
csa_table[i][1] = FIX(ca);
}
/* compute mdct windows */
for(i=0;i<36;i++) {
int v;
v = FIXR(sin(M_PI * (i + 0.5) / 36.0));
mdct_win[0][i] = v;
mdct_win[1][i] = v;
mdct_win[3][i] = v;
}
for(i=0;i<6;i++) {
mdct_win[1][18 + i] = FIXR(1.0);
mdct_win[1][24 + i] = FIXR(sin(M_PI * ((i + 6) + 0.5) / 12.0));
mdct_win[1][30 + i] = FIXR(0.0);
mdct_win[3][i] = FIXR(0.0);
mdct_win[3][6 + i] = FIXR(sin(M_PI * (i + 0.5) / 12.0));
mdct_win[3][12 + i] = FIXR(1.0);
}
for(i=0;i<12;i++)
mdct_win[2][i] = FIXR(sin(M_PI * (i + 0.5) / 12.0));
/* NOTE: we do frequency inversion adter the MDCT by changing
the sign of the right window coefs */
for(j=0;j<4;j++) {
for(i=0;i<36;i+=2) {
mdct_win[j + 4][i] = mdct_win[j][i];
mdct_win[j + 4][i + 1] = -mdct_win[j][i + 1];
}
}
#if defined(DEBUG)
for(j=0;j<8;j++) {
printf("win%d=\n", j);
for(i=0;i<36;i++)
printf("%f, ", (double)mdct_win[j][i] / FRAC_ONE);
printf("\n");
}
#endif
init = 1;
make_decode_tables(32767);
init_layer2();
init_layer3(SBLIMIT);
}
s->inbuf_index = 0;
s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
s->inbuf_ptr = s->inbuf;
#ifdef DEBUG
s->frame_count = 0;
#endif
return 0;
}
/* tab[i][j] = 1.0 / (2.0 * cos(pi*(2*k+1) / 2^(6 - j))) */;
/* cos(i*pi/64) */
#define COS0_0 FIXR(0.50060299823519630134)
#define COS0_1 FIXR(0.50547095989754365998)
#define COS0_2 FIXR(0.51544730992262454697)
#define COS0_3 FIXR(0.53104259108978417447)
#define COS0_4 FIXR(0.55310389603444452782)
#define COS0_5 FIXR(0.58293496820613387367)
#define COS0_6 FIXR(0.62250412303566481615)
#define COS0_7 FIXR(0.67480834145500574602)
#define COS0_8 FIXR(0.74453627100229844977)
#define COS0_9 FIXR(0.83934964541552703873)
#define COS0_10 FIXR(0.97256823786196069369)
#define COS0_11 FIXR(1.16943993343288495515)
#define COS0_12 FIXR(1.48416461631416627724)
#define COS0_13 FIXR(2.05778100995341155085)
#define COS0_14 FIXR(3.40760841846871878570)
#define COS0_15 FIXR(10.19000812354805681150)
#define COS1_0 FIXR(0.50241928618815570551)
#define COS1_1 FIXR(0.52249861493968888062)
#define COS1_2 FIXR(0.56694403481635770368)
#define COS1_3 FIXR(0.64682178335999012954)
#define COS1_4 FIXR(0.78815462345125022473)
#define COS1_5 FIXR(1.06067768599034747134)
#define COS1_6 FIXR(1.72244709823833392782)
#define COS1_7 FIXR(5.10114861868916385802)
#define COS2_0 FIXR(0.50979557910415916894)
#define COS2_1 FIXR(0.60134488693504528054)
#define COS2_2 FIXR(0.89997622313641570463)
#define COS2_3 FIXR(2.56291544774150617881)
#define COS3_0 FIXR(0.54119610014619698439)
#define COS3_1 FIXR(1.30656296487637652785)
#define COS4_0 FIXR(0.70710678118654752439)
/* butterfly operator */
#define BF(a, b, c)\
{\
tmp0 = tab[a] + tab[b];\
tmp1 = tab[a] - tab[b];\
tab[a] = tmp0;\
tab[b] = MULL(tmp1, c);\
}
#define BF1(a, b, c, d)\
{\
BF(a, b, COS4_0);\
BF(c, d, -COS4_0);\
tab[c] += tab[d];\
}
#define BF2(a, b, c, d)\
{\
BF(a, b, COS4_0);\
BF(c, d, -COS4_0);\
tab[c] += tab[d];\
tab[a] += tab[c];\
tab[c] += tab[b];\
tab[b] += tab[d];\
}
#define ADD(a, b) tab[a] += tab[b]
/* DCT32 without 1/sqrt(2) coef zero scaling. */
static void dct32(INT32 *out, INT32 *tab)
{
int tmp0, tmp1;
/* pass 1 */
BF(0, 31, COS0_0);
BF(1, 30, COS0_1);
BF(2, 29, COS0_2);
BF(3, 28, COS0_3);
BF(4, 27, COS0_4);
BF(5, 26, COS0_5);
BF(6, 25, COS0_6);
BF(7, 24, COS0_7);
BF(8, 23, COS0_8);
BF(9, 22, COS0_9);
BF(10, 21, COS0_10);
BF(11, 20, COS0_11);
BF(12, 19, COS0_12);
BF(13, 18, COS0_13);
BF(14, 17, COS0_14);
BF(15, 16, COS0_15);
/* pass 2 */
BF(0, 15, COS1_0);
BF(1, 14, COS1_1);
BF(2, 13, COS1_2);
BF(3, 12, COS1_3);
BF(4, 11, COS1_4);
BF(5, 10, COS1_5);
BF(6, 9, COS1_6);
BF(7, 8, COS1_7);
BF(16, 31, -COS1_0);
BF(17, 30, -COS1_1);
BF(18, 29, -COS1_2);
BF(19, 28, -COS1_3);
BF(20, 27, -COS1_4);
BF(21, 26, -COS1_5);
BF(22, 25, -COS1_6);
BF(23, 24, -COS1_7);
/* pass 3 */
BF(0, 7, COS2_0);
BF(1, 6, COS2_1);
BF(2, 5, COS2_2);
BF(3, 4, COS2_3);
BF(8, 15, -COS2_0);
BF(9, 14, -COS2_1);
BF(10, 13, -COS2_2);
BF(11, 12, -COS2_3);
BF(16, 23, COS2_0);
BF(17, 22, COS2_1);
BF(18, 21, COS2_2);
BF(19, 20, COS2_3);
BF(24, 31, -COS2_0);
BF(25, 30, -COS2_1);
BF(26, 29, -COS2_2);
BF(27, 28, -COS2_3);
/* pass 4 */
BF(0, 3, COS3_0);
BF(1, 2, COS3_1);
BF(4, 7, -COS3_0);
BF(5, 6, -COS3_1);
BF(8, 11, COS3_0);
BF(9, 10, COS3_1);
BF(12, 15, -COS3_0);
BF(13, 14, -COS3_1);
BF(16, 19, COS3_0);
BF(17, 18, COS3_1);
BF(20, 23, -COS3_0);
BF(21, 22, -COS3_1);
BF(24, 27, COS3_0);
BF(25, 26, COS3_1);
BF(28, 31, -COS3_0);
BF(29, 30, -COS3_1);
/* pass 5 */
BF1(0, 1, 2, 3);
BF2(4, 5, 6, 7);
BF1(8, 9, 10, 11);
BF2(12, 13, 14, 15);
BF1(16, 17, 18, 19);
BF2(20, 21, 22, 23);
BF1(24, 25, 26, 27);
BF2(28, 29, 30, 31);
/* pass 6 */
ADD( 8, 12);
ADD(12, 10);
ADD(10, 14);
ADD(14, 9);
ADD( 9, 13);
ADD(13, 11);
ADD(11, 15);
out[ 0] = tab[0];
out[16] = tab[1];
out[ 8] = tab[2];
out[24] = tab[3];
out[ 4] = tab[4];
out[20] = tab[5];
out[12] = tab[6];
out[28] = tab[7];
out[ 2] = tab[8];
out[18] = tab[9];
out[10] = tab[10];
out[26] = tab[11];
out[ 6] = tab[12];
out[22] = tab[13];
out[14] = tab[14];
out[30] = tab[15];
ADD(24, 28);
ADD(28, 26);
ADD(26, 30);
ADD(30, 25);
ADD(25, 29);
ADD(29, 27);
ADD(27, 31);
out[ 1] = tab[16] + tab[24];
out[17] = tab[17] + tab[25];
out[ 9] = tab[18] + tab[26];
out[25] = tab[19] + tab[27];
out[ 5] = tab[20] + tab[28];
out[21] = tab[21] + tab[29];
out[13] = tab[22] + tab[30];
out[29] = tab[23] + tab[31];
out[ 3] = tab[24] + tab[20];
out[19] = tab[25] + tab[21];
out[11] = tab[26] + tab[22];
out[27] = tab[27] + tab[23];
out[ 7] = tab[28] + tab[18];
out[23] = tab[29] + tab[19];
out[15] = tab[30] + tab[17];
out[31] = tab[31];
}
#define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)
#if FRAC_BITS <= 15
#define OUT_SAMPLE(sum)\
{\
int sum1;\
sum1 = (sum + (1 << (OUT_SHIFT - 1))) >> OUT_SHIFT;\
if (sum1 < -32768)\
sum1 = -32768;\
else if (sum1 > 32767)\
sum1 = 32767;\
*samples = sum1;\
samples += incr;\
}
#define SUM8(off, op) \
{ \
sum op w[0 * 64 + off] * p[0 * 64];\
sum op w[1 * 64 + off] * p[1 * 64];\
sum op w[2 * 64 + off] * p[2 * 64];\
sum op w[3 * 64 + off] * p[3 * 64];\
sum op w[4 * 64 + off] * p[4 * 64];\
sum op w[5 * 64 + off] * p[5 * 64];\
sum op w[6 * 64 + off] * p[6 * 64];\
sum op w[7 * 64 + off] * p[7 * 64];\
}
#else
#define OUT_SAMPLE(sum)\
{\
int sum1;\
sum1 = (int)((sum + (INT64_C(1) << (OUT_SHIFT - 1))) >> OUT_SHIFT);\
if (sum1 < -32768)\
sum1 = -32768;\
else if (sum1 > 32767)\
sum1 = 32767;\
*samples = sum1;\
samples += incr;\
}
#define SUM8(off, op) \
{ \
sum op MUL64(w[0 * 64 + off], p[0 * 64]);\
sum op MUL64(w[1 * 64 + off], p[1 * 64]);\
sum op MUL64(w[2 * 64 + off], p[2 * 64]);\
sum op MUL64(w[3 * 64 + off], p[3 * 64]);\
sum op MUL64(w[4 * 64 + off], p[4 * 64]);\
sum op MUL64(w[5 * 64 + off], p[5 * 64]);\
sum op MUL64(w[6 * 64 + off], p[6 * 64]);\
sum op MUL64(w[7 * 64 + off], p[7 * 64]);\
}
#endif
/* 32 sub band synthesis filter. Input: 32 sub band samples, Output:
32 samples. */
/* XXX: optimize by avoiding ring buffer usage */
static void synth_filter(MPADecodeContext *s1,
int ch, INT16 *samples, int incr,
INT32 sb_samples[SBLIMIT])
{
INT32 tmp[32];
register MPA_INT *synth_buf, *p;
register MPA_INT *w;
int j, offset, v;
#if FRAC_BITS <= 15
int sum;
#else
INT64 sum;
#endif
dct32(tmp, sb_samples);
offset = s1->synth_buf_offset[ch];
synth_buf = s1->synth_buf[ch] + offset;
for(j=0;j<32;j++) {
v = tmp[j];
#if FRAC_BITS <= 15
if (v > 32767)
v = 32767;
else if (v < -32768)
v = -32768;
#endif
synth_buf[j] = v;
}
/* copy to avoid wrap */
memcpy(synth_buf + 512, synth_buf, 32 * sizeof(MPA_INT));
w = window;
for(j=0;j<16;j++) {
sum = 0;
p = synth_buf + 16 + j; /* 0-15 */
SUM8(0, +=);
p = synth_buf + 48 - j; /* 32-47 */
SUM8(32, -=);
OUT_SAMPLE(sum);
w++;
}
p = synth_buf + 32; /* 48 */
sum = 0;
SUM8(32, -=);
OUT_SAMPLE(sum);
w++;
for(j=17;j<32;j++) {
sum = 0;
p = synth_buf + 48 - j; /* 17-31 */
SUM8(0, -=);
p = synth_buf + 16 + j; /* 49-63 */
SUM8(32, -=);
OUT_SAMPLE(sum);
w++;
}
offset = (offset - 32) & 511;
s1->synth_buf_offset[ch] = offset;
}
/* cos(pi*i/24) */
#define C1 FIXR(0.99144486137381041114)
#define C3 FIXR(0.92387953251128675612)
#define C5 FIXR(0.79335334029123516458)
#define C7 FIXR(0.60876142900872063941)
#define C9 FIXR(0.38268343236508977173)
#define C11 FIXR(0.13052619222005159154)
/* 12 points IMDCT. We compute it "by hand" by factorizing obvious
cases. */
static void imdct12(int *out, int *in)
{
int tmp;
INT64 in1_3, in1_9, in4_3, in4_9;
in1_3 = MUL64(in[1], C3);
in1_9 = MUL64(in[1], C9);
in4_3 = MUL64(in[4], C3);
in4_9 = MUL64(in[4], C9);
tmp = FRAC_RND(MUL64(in[0], C7) - in1_3 - MUL64(in[2], C11) +
MUL64(in[3], C1) - in4_9 - MUL64(in[5], C5));
out[0] = tmp;
out[5] = -tmp;
tmp = FRAC_RND(MUL64(in[0] - in[3], C9) - in1_3 +
MUL64(in[2] + in[5], C3) - in4_9);
out[1] = tmp;
out[4] = -tmp;
tmp = FRAC_RND(MUL64(in[0], C11) - in1_9 + MUL64(in[2], C7) -
MUL64(in[3], C5) + in4_3 - MUL64(in[5], C1));
out[2] = tmp;
out[3] = -tmp;
tmp = FRAC_RND(MUL64(-in[0], C5) + in1_9 + MUL64(in[2], C1) +
MUL64(in[3], C11) - in4_3 - MUL64(in[5], C7));
out[6] = tmp;
out[11] = tmp;
tmp = FRAC_RND(MUL64(-in[0] + in[3], C3) - in1_9 +
MUL64(in[2] + in[5], C9) + in4_3);
out[7] = tmp;
out[10] = tmp;
tmp = FRAC_RND(-MUL64(in[0], C1) - in1_3 - MUL64(in[2], C5) -
MUL64(in[3], C7) - in4_9 - MUL64(in[5], C11));
out[8] = tmp;
out[9] = tmp;
}
#undef C1
#undef C3
#undef C5
#undef C7
#undef C9
#undef C11
/* cos(pi*i/18) */
#define C1 FIXR(0.98480775301220805936)
#define C2 FIXR(0.93969262078590838405)
#define C3 FIXR(0.86602540378443864676)
#define C4 FIXR(0.76604444311897803520)
#define C5 FIXR(0.64278760968653932632)
#define C6 FIXR(0.5)
#define C7 FIXR(0.34202014332566873304)
#define C8 FIXR(0.17364817766693034885)
/* 0.5 / cos(pi*(2*i+1)/36) */
static const int icos36[9] = {
FIXR(0.50190991877167369479),
FIXR(0.51763809020504152469),
FIXR(0.55168895948124587824),
FIXR(0.61038729438072803416),
FIXR(0.70710678118654752439),
FIXR(0.87172339781054900991),
FIXR(1.18310079157624925896),
FIXR(1.93185165257813657349),
FIXR(5.73685662283492756461),
};
static const int icos72[18] = {
/* 0.5 / cos(pi*(2*i+19)/72) */
FIXR(0.74009361646113053152),
FIXR(0.82133981585229078570),
FIXR(0.93057949835178895673),
FIXR(1.08284028510010010928),
FIXR(1.30656296487637652785),
FIXR(1.66275476171152078719),
FIXR(2.31011315767264929558),
FIXR(3.83064878777019433457),
FIXR(11.46279281302667383546),
/* 0.5 / cos(pi*(2*(i + 18) +19)/72) */
FIXR(-0.67817085245462840086),
FIXR(-0.63023620700513223342),
FIXR(-0.59284452371708034528),
FIXR(-0.56369097343317117734),
FIXR(-0.54119610014619698439),
FIXR(-0.52426456257040533932),
FIXR(-0.51213975715725461845),
FIXR(-0.50431448029007636036),
FIXR(-0.50047634258165998492),
};
/* using Lee like decomposition followed by hand coded 9 points DCT */
static void imdct36(int *out, int *in)
{
int i, j, t0, t1, t2, t3, s0, s1, s2, s3;
int tmp[18], *tmp1, *in1;
INT64 in3_3, in6_6;
for(i=17;i>=1;i--)
in[i] += in[i-1];
for(i=17;i>=3;i-=2)
in[i] += in[i-2];
for(j=0;j<2;j++) {
tmp1 = tmp + j;
in1 = in + j;
in3_3 = MUL64(in1[2*3], C3);
in6_6 = MUL64(in1[2*6], C6);
tmp1[0] = FRAC_RND(MUL64(in1[2*1], C1) + in3_3 +
MUL64(in1[2*5], C5) + MUL64(in1[2*7], C7));
tmp1[2] = in1[2*0] + FRAC_RND(MUL64(in1[2*2], C2) +
MUL64(in1[2*4], C4) + in6_6 +
MUL64(in1[2*8], C8));
tmp1[4] = FRAC_RND(MUL64(in1[2*1] - in1[2*5] - in1[2*7], C3));
tmp1[6] = FRAC_RND(MUL64(in1[2*2] - in1[2*4] - in1[2*8], C6)) -
in1[2*6] + in1[2*0];
tmp1[8] = FRAC_RND(MUL64(in1[2*1], C5) - in3_3 -
MUL64(in1[2*5], C7) + MUL64(in1[2*7], C1));
tmp1[10] = in1[2*0] + FRAC_RND(MUL64(-in1[2*2], C8) -
MUL64(in1[2*4], C2) + in6_6 +
MUL64(in1[2*8], C4));
tmp1[12] = FRAC_RND(MUL64(in1[2*1], C7) - in3_3 +
MUL64(in1[2*5], C1) -
MUL64(in1[2*7], C5));
tmp1[14] = in1[2*0] + FRAC_RND(MUL64(-in1[2*2], C4) +
MUL64(in1[2*4], C8) + in6_6 -
MUL64(in1[2*8], C2));
tmp1[16] = in1[2*0] - in1[2*2] + in1[2*4] - in1[2*6] + in1[2*8];
}
i = 0;
for(j=0;j<4;j++) {
t0 = tmp[i];
t1 = tmp[i + 2];
s0 = t1 + t0;
s2 = t1 - t0;
t2 = tmp[i + 1];
t3 = tmp[i + 3];
s1 = MULL(t3 + t2, icos36[j]);
s3 = MULL(t3 - t2, icos36[8 - j]);
t0 = MULL(s0 + s1, icos72[9 + 8 - j]);
t1 = MULL(s0 - s1, icos72[8 - j]);
out[18 + 9 + j] = t0;
out[18 + 8 - j] = t0;
out[9 + j] = -t1;
out[8 - j] = t1;
t0 = MULL(s2 + s3, icos72[9+j]);
t1 = MULL(s2 - s3, icos72[j]);
out[18 + 9 + (8 - j)] = t0;
out[18 + j] = t0;
out[9 + (8 - j)] = -t1;
out[j] = t1;
i += 4;
}
s0 = tmp[16];
s1 = MULL(tmp[17], icos36[4]);
t0 = MULL(s0 + s1, icos72[9 + 4]);
t1 = MULL(s0 - s1, icos72[4]);
out[18 + 9 + 4] = t0;
out[18 + 8 - 4] = t0;
out[9 + 4] = -t1;
out[8 - 4] = t1;
}
/* fast header check for resync */
static int check_header(UINT32 header)
{
......@@ -95,9 +953,8 @@ static int check_header(UINT32 header)
/* layer check */
if (((header >> 17) & 3) == 0)
return -1;
/* bit rate : currently no free format supported */
if (((header >> 12) & 0xf) == 0xf ||
((header >> 12) & 0xf) == 0x0)
/* bit rate */
if (((header >> 12) & 0xf) == 0xf)
return -1;
/* frequency */
if (((header >> 10) & 3) == 3)
......@@ -105,123 +962,1281 @@ static int check_header(UINT32 header)
return 0;
}
/* header + layer + bitrate + freq + lsf/mpeg25 */
#define SAME_HEADER_MASK \
(0xffe00000 | (3 << 17) | (0xf << 12) | (3 << 10) | (3 << 19))
/* header decoding. MUST check the header before because no
consistency check is done there */
static void decode_header(MPADecodeContext *s, UINT32 header)
consistency check is done there. Return 1 if free format found and
that the frame size must be computed externally */
static int decode_header(MPADecodeContext *s, UINT32 header)
{
struct frame *fr = &s->mpstr.fr;
int sample_rate, frame_size;
int sample_rate, frame_size, mpeg25, padding;
int sample_rate_index, bitrate_index;
if (header & (1<<20)) {
fr->lsf = (header & (1<<19)) ? 0 : 1;
fr->mpeg25 = 0;
s->lsf = (header & (1<<19)) ? 0 : 1;
mpeg25 = 0;
} else {
fr->lsf = 1;
fr->mpeg25 = 1;
s->lsf = 1;
mpeg25 = 1;
}
s->layer = 4 - ((header >> 17) & 3);
/* extract frequency */
fr->sampling_frequency = ((header >> 10) & 3);
sample_rate = mp_freq_tab[fr->sampling_frequency] >> (fr->lsf + fr->mpeg25);
fr->sampling_frequency += 3 * (fr->lsf + fr->mpeg25);
s->error_protection = ((header>>16) & 1) ^ 1;
sample_rate_index = (header >> 10) & 3;
sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);
sample_rate_index += 3 * (s->lsf + mpeg25);
s->sample_rate_index = sample_rate_index;
s->error_protection = ((header >> 16) & 1) ^ 1;
fr->bitrate_index = ((header>>12)&0xf);
fr->padding = ((header>>9)&0x1);
fr->extension = ((header>>8)&0x1);
fr->mode = ((header>>6)&0x3);
fr->mode_ext = ((header>>4)&0x3);
fr->copyright = ((header>>3)&0x1);
fr->original = ((header>>2)&0x1);
fr->emphasis = header & 0x3;
fr->stereo = (fr->mode == MPG_MD_MONO) ? 1 : 2;
bitrate_index = (header >> 12) & 0xf;
padding = (header >> 9) & 1;
//extension = (header >> 8) & 1;
s->mode = (header >> 6) & 3;
s->mode_ext = (header >> 4) & 3;
//copyright = (header >> 3) & 1;
//original = (header >> 2) & 1;
//emphasis = header & 3;
if (s->mode == MPA_MONO)
s->nb_channels = 1;
else
s->nb_channels = 2;
frame_size = mp_bitrate_tab[fr->lsf][s->layer - 1][fr->bitrate_index];
s->bit_rate = frame_size * 1000;
switch(s->layer) {
case 1:
frame_size = (frame_size * 12000) / sample_rate;
frame_size = ((frame_size + fr->padding) << 2);
break;
case 2:
frame_size = (frame_size * 144000) / sample_rate;
frame_size += fr->padding;
break;
case 3:
frame_size = (frame_size * 144000) / (sample_rate << fr->lsf);
frame_size += fr->padding;
break;
if (bitrate_index != 0) {
frame_size = mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];
s->bit_rate = frame_size * 1000;
switch(s->layer) {
case 1:
frame_size = (frame_size * 12000) / sample_rate;
frame_size = (frame_size + padding) * 4;
break;
case 2:
frame_size = (frame_size * 144000) / sample_rate;
frame_size += padding;
break;
default:
case 3:
frame_size = (frame_size * 144000) / (sample_rate << s->lsf);
frame_size += padding;
break;
}
s->frame_size = frame_size;
} else {
/* if no frame size computed, signal it */
if (!s->free_format_frame_size)
return 1;
/* free format: compute bitrate and real frame size from the
frame size we extracted by reading the bitstream */
s->frame_size = s->free_format_frame_size;
switch(s->layer) {
case 1:
s->frame_size += padding * 4;
s->bit_rate = (s->frame_size * sample_rate) / 48000;
break;
case 2:
s->frame_size += padding;
s->bit_rate = (s->frame_size * sample_rate) / 144000;
break;
default:
case 3:
s->frame_size += padding;
s->bit_rate = (s->frame_size * (sample_rate << s->lsf)) / 144000;
break;
}
}
s->frame_size = frame_size;
s->sample_rate = sample_rate;
#if 0
printf("layer%d, %d Hz, %d kbits/s, %s\n",
s->layer, s->sample_rate, s->bit_rate, fr->stereo ? "stereo" : "mono");
#ifdef DEBUG
printf("layer%d, %d Hz, %d kbits/s, ",
s->layer, s->sample_rate, s->bit_rate);
if (s->nb_channels == 2) {
if (s->layer == 3) {
if (s->mode_ext & MODE_EXT_MS_STEREO)
printf("ms-");
if (s->mode_ext & MODE_EXT_I_STEREO)
printf("i-");
}
printf("stereo");
} else {
printf("mono");
}
printf("\n");
#endif
return 0;
}
static int mp_decode_frame(MPADecodeContext *s,
short *samples)
/* return the number of decoded frames */
static int mp_decode_layer1(MPADecodeContext *s)
{
int nb_bytes;
int bound, i, v, n, ch, j, mant;
UINT8 allocation[MPA_MAX_CHANNELS][SBLIMIT];
UINT8 scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
if (s->mode == MPA_JSTEREO)
bound = (s->mode_ext + 1) * 4;
else
bound = SBLIMIT;
/* allocation bits */
for(i=0;i<bound;i++) {
for(ch=0;ch<s->nb_channels;ch++) {
allocation[ch][i] = get_bits(&s->gb, 4);
}
}
for(i=bound;i<SBLIMIT;i++) {
allocation[0][i] = get_bits(&s->gb, 4);
}
/* scale factors */
for(i=0;i<bound;i++) {
for(ch=0;ch<s->nb_channels;ch++) {
if (allocation[ch][i])
scale_factors[ch][i] = get_bits(&s->gb, 6);
}
}
for(i=bound;i<SBLIMIT;i++) {
if (allocation[0][i]) {
scale_factors[0][i] = get_bits(&s->gb, 6);
scale_factors[1][i] = get_bits(&s->gb, 6);
}
}
init_get_bits(&s->gb, s->inbuf + HEADER_SIZE, s->inbuf_ptr - s->inbuf - HEADER_SIZE);
/* compute samples */
for(j=0;j<12;j++) {
for(i=0;i<bound;i++) {
for(ch=0;ch<s->nb_channels;ch++) {
n = allocation[ch][i];
if (n) {
mant = get_bits(&s->gb, n + 1);
v = l1_unscale(n, mant, scale_factors[ch][i]);
} else {
v = 0;
}
s->sb_samples[ch][j][i] = v;
}
}
for(i=bound;i<SBLIMIT;i++) {
n = allocation[0][i];
if (n) {
mant = get_bits(&s->gb, n + 1);
v = l1_unscale(n, mant, scale_factors[0][i]);
s->sb_samples[0][j][i] = v;
v = l1_unscale(n, mant, scale_factors[1][i]);
s->sb_samples[1][j][i] = v;
} else {
s->sb_samples[0][j][i] = 0;
s->sb_samples[1][j][i] = 0;
}
}
}
return 12;
}
/* bitrate is in kb/s */
int l2_select_table(int bitrate, int nb_channels, int freq, int lsf)
{
int ch_bitrate, table;
/* skip error protection field */
if (s->error_protection)
get_bits(&s->gb, 16);
ch_bitrate = bitrate / nb_channels;
if (!lsf) {
if ((freq == 48000 && ch_bitrate >= 56) ||
(ch_bitrate >= 56 && ch_bitrate <= 80))
table = 0;
else if (freq != 48000 && ch_bitrate >= 96)
table = 1;
else if (freq != 32000 && ch_bitrate <= 48)
table = 2;
else
table = 3;
} else {
table = 4;
}
return table;
}
/* XXX: horrible: global! */
gmp = &s->mpstr;
gmp_s = s;
gmp_gb = &s->gb;
static int mp_decode_layer2(MPADecodeContext *s)
{
int sblimit; /* number of used subbands */
const unsigned char *alloc_table;
int table, bit_alloc_bits, i, j, ch, bound, v;
unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
int scale, qindex, bits, steps, k, l, m, b;
nb_bytes = 0;
switch(s->layer) {
case 1:
do_layer1(&s->mpstr.fr,(unsigned char *)samples, &nb_bytes);
break;
case 2:
do_layer2(&s->mpstr.fr,(unsigned char *)samples, &nb_bytes);
break;
case 3:
do_layer3(&s->mpstr.fr,(unsigned char *)samples, &nb_bytes);
s->inbuf_index ^= 1;
s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
s->old_frame_size = s->frame_size;
break;
default:
break;
/* select decoding table */
table = l2_select_table(s->bit_rate / 1000, s->nb_channels,
s->sample_rate, s->lsf);
sblimit = sblimit_table[table];
alloc_table = alloc_tables[table];
if (s->mode == MPA_JSTEREO)
bound = (s->mode_ext + 1) * 4;
else
bound = sblimit;
dprintf("bound=%d sblimit=%d\n", bound, sblimit);
/* parse bit allocation */
j = 0;
for(i=0;i<bound;i++) {
bit_alloc_bits = alloc_table[j];
for(ch=0;ch<s->nb_channels;ch++) {
bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
}
j += 1 << bit_alloc_bits;
}
for(i=bound;i<sblimit;i++) {
bit_alloc_bits = alloc_table[j];
v = get_bits(&s->gb, bit_alloc_bits);
bit_alloc[0][i] = v;
bit_alloc[1][i] = v;
j += 1 << bit_alloc_bits;
}
return nb_bytes;
#ifdef DEBUG
{
for(ch=0;ch<s->nb_channels;ch++) {
for(i=0;i<sblimit;i++)
printf(" %d", bit_alloc[ch][i]);
printf("\n");
}
}
#endif
/* scale codes */
for(i=0;i<sblimit;i++) {
for(ch=0;ch<s->nb_channels;ch++) {
if (bit_alloc[ch][i])
scale_code[ch][i] = get_bits(&s->gb, 2);
}
}
/* scale factors */
for(i=0;i<sblimit;i++) {
for(ch=0;ch<s->nb_channels;ch++) {
if (bit_alloc[ch][i]) {
sf = scale_factors[ch][i];
switch(scale_code[ch][i]) {
default:
case 0:
sf[0] = get_bits(&s->gb, 6);
sf[1] = get_bits(&s->gb, 6);
sf[2] = get_bits(&s->gb, 6);
break;
case 2:
sf[0] = get_bits(&s->gb, 6);
sf[1] = sf[0];
sf[2] = sf[0];
break;
case 1:
sf[0] = get_bits(&s->gb, 6);
sf[2] = get_bits(&s->gb, 6);
sf[1] = sf[0];
break;
case 3:
sf[0] = get_bits(&s->gb, 6);
sf[2] = get_bits(&s->gb, 6);
sf[1] = sf[2];
break;
}
}
}
}
#ifdef DEBUG
for(ch=0;ch<s->nb_channels;ch++) {
for(i=0;i<sblimit;i++) {
if (bit_alloc[ch][i]) {
sf = scale_factors[ch][i];
printf(" %d %d %d", sf[0], sf[1], sf[2]);
} else {
printf(" -");
}
}
printf("\n");
}
#endif
/* samples */
for(k=0;k<3;k++) {
for(l=0;l<12;l+=3) {
j = 0;
for(i=0;i<bound;i++) {
bit_alloc_bits = alloc_table[j];
for(ch=0;ch<s->nb_channels;ch++) {
b = bit_alloc[ch][i];
if (b) {
scale = scale_factors[ch][i][k];
qindex = alloc_table[j+b];
bits = quant_bits[qindex];
if (bits < 0) {
/* 3 values at the same time */
v = get_bits(&s->gb, -bits);
steps = quant_steps[qindex];
s->sb_samples[ch][k * 12 + l + 0][i] =
l2_unscale_group(steps, v % steps, scale);
v = v / steps;
s->sb_samples[ch][k * 12 + l + 1][i] =
l2_unscale_group(steps, v % steps, scale);
v = v / steps;
s->sb_samples[ch][k * 12 + l + 2][i] =
l2_unscale_group(steps, v, scale);
} else {
for(m=0;m<3;m++) {
v = get_bits(&s->gb, bits);
v = l1_unscale(bits - 1, v, scale);
s->sb_samples[ch][k * 12 + l + m][i] = v;
}
}
} else {
s->sb_samples[ch][k * 12 + l + 0][i] = 0;
s->sb_samples[ch][k * 12 + l + 1][i] = 0;
s->sb_samples[ch][k * 12 + l + 2][i] = 0;
}
}
/* next subband in alloc table */
j += 1 << bit_alloc_bits;
}
/* XXX: find a way to avoid this duplication of code */
for(i=bound;i<sblimit;i++) {
bit_alloc_bits = alloc_table[j];
b = bit_alloc[0][i];
if (b) {
int mant, scale0, scale1;
scale0 = scale_factors[0][i][k];
scale1 = scale_factors[1][i][k];
qindex = alloc_table[j+b];
bits = quant_bits[qindex];
if (bits < 0) {
/* 3 values at the same time */
v = get_bits(&s->gb, -bits);
steps = quant_steps[qindex];
mant = v % steps;
v = v / steps;
s->sb_samples[0][k * 12 + l + 0][i] =
l2_unscale_group(steps, mant, scale0);
s->sb_samples[1][k * 12 + l + 0][i] =
l2_unscale_group(steps, mant, scale1);
mant = v % steps;
v = v / steps;
s->sb_samples[0][k * 12 + l + 1][i] =
l2_unscale_group(steps, mant, scale0);
s->sb_samples[1][k * 12 + l + 1][i] =
l2_unscale_group(steps, mant, scale1);
s->sb_samples[0][k * 12 + l + 2][i] =
l2_unscale_group(steps, v, scale0);
s->sb_samples[1][k * 12 + l + 2][i] =
l2_unscale_group(steps, v, scale1);
} else {
for(m=0;m<3;m++) {
mant = get_bits(&s->gb, bits);
s->sb_samples[0][k * 12 + l + m][i] =
l1_unscale(bits - 1, mant, scale0);
s->sb_samples[1][k * 12 + l + m][i] =
l1_unscale(bits - 1, mant, scale1);
}
}
} else {
s->sb_samples[0][k * 12 + l + 0][i] = 0;
s->sb_samples[0][k * 12 + l + 1][i] = 0;
s->sb_samples[0][k * 12 + l + 2][i] = 0;
s->sb_samples[1][k * 12 + l + 0][i] = 0;
s->sb_samples[1][k * 12 + l + 1][i] = 0;
s->sb_samples[1][k * 12 + l + 2][i] = 0;
}
/* next subband in alloc table */
j += 1 << bit_alloc_bits;
}
/* fill remaining samples to zero */
for(i=sblimit;i<SBLIMIT;i++) {
for(ch=0;ch<s->nb_channels;ch++) {
s->sb_samples[ch][k * 12 + l + 0][i] = 0;
s->sb_samples[ch][k * 12 + l + 1][i] = 0;
s->sb_samples[ch][k * 12 + l + 2][i] = 0;
}
}
}
}
return 3 * 12;
}
/*
* seek back in the stream for backstep bytes (at most 511 bytes, and
* at most in last frame). Note that this is slightly incorrect (data
* can span more than one block!)
* Seek back in the stream for backstep bytes (at most 511 bytes)
*/
int set_pointer(long backstep)
static void seek_to_maindata(MPADecodeContext *s, long backstep)
{
UINT8 *ptr;
/* compute current position in stream */
ptr = gmp_gb->buf_ptr - (gmp_gb->bit_cnt >> 3);
ptr = s->gb.buf_ptr - (s->gb.bit_cnt >> 3);
/* copy old data before current one */
ptr -= backstep;
memcpy(ptr, gmp_s->inbuf1[gmp_s->inbuf_index ^ 1] +
BACKSTEP_SIZE + gmp_s->old_frame_size - backstep, backstep);
memcpy(ptr, s->inbuf1[s->inbuf_index ^ 1] +
BACKSTEP_SIZE + s->old_frame_size - backstep, backstep);
/* init get bits again */
init_get_bits(gmp_gb, ptr, gmp_s->frame_size + backstep);
init_get_bits(&s->gb, ptr, s->frame_size + backstep);
/* prepare next buffer */
s->inbuf_index ^= 1;
s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
s->old_frame_size = s->frame_size;
}
static inline void lsf_sf_expand(int *slen,
int sf, int n1, int n2, int n3)
{
if (n3) {
slen[3] = sf % n3;
sf /= n3;
} else {
slen[3] = 0;
}
if (n2) {
slen[2] = sf % n2;
sf /= n2;
} else {
slen[2] = 0;
}
slen[1] = sf % n1;
sf /= n1;
slen[0] = sf;
}
static void exponents_from_scale_factors(MPADecodeContext *s,
GranuleDef *g,
INT16 *exponents)
{
const UINT8 *bstab, *pretab;
int len, i, j, k, l, v0, shift, gain, gains[3];
INT16 *exp_ptr;
exp_ptr = exponents;
gain = g->global_gain - 210;
shift = g->scalefac_scale + 1;
bstab = band_size_long[s->sample_rate_index];
pretab = mpa_pretab[g->preflag];
for(i=0;i<g->long_end;i++) {
v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift);
len = bstab[i];
for(j=len;j>0;j--)
*exp_ptr++ = v0;
}
if (g->short_start < 13) {
bstab = band_size_short[s->sample_rate_index];
gains[0] = gain - (g->subblock_gain[0] << 3);
gains[1] = gain - (g->subblock_gain[1] << 3);
gains[2] = gain - (g->subblock_gain[2] << 3);
k = g->long_end;
for(i=g->short_start;i<13;i++) {
len = bstab[i];
for(l=0;l<3;l++) {
v0 = gains[l] - (g->scale_factors[k++] << shift);
for(j=len;j>0;j--)
*exp_ptr++ = v0;
}
}
}
}
/* handle n = 0 too */
static inline int get_bitsz(GetBitContext *s, int n)
{
if (n == 0)
return 0;
else
return get_bits(s, n);
}
static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
INT16 *exponents, int end_pos)
{
int s_index;
int linbits, code, x, y, l, v, i, j, k, pos;
UINT8 *last_buf_ptr;
UINT32 last_bit_buf;
int last_bit_cnt;
VLC *vlc;
UINT8 *code_table;
/* low frequencies (called big values) */
s_index = 0;
for(i=0;i<3;i++) {
j = g->region_size[i];
if (j == 0)
continue;
/* select vlc table */
k = g->table_select[i];
l = mpa_huff_data[k][0];
linbits = mpa_huff_data[k][1];
vlc = &huff_vlc[l];
code_table = huff_code_table[l];
/* read huffcode and compute each couple */
for(;j>0;j--) {
if (get_bits_count(&s->gb) >= end_pos)
break;
if (code_table) {
code = get_vlc(&s->gb, vlc);
if (code < 0)
return -1;
y = code_table[code];
x = y >> 4;
y = y & 0x0f;
} else {
x = 0;
y = 0;
}
dprintf("region=%d n=%d x=%d y=%d exp=%d\n",
i, g->region_size[i] - j, x, y, exponents[s_index]);
if (x) {
if (x == 15)
x += get_bitsz(&s->gb, linbits);
v = l3_unscale(x, exponents[s_index]);
if (get_bits1(&s->gb))
v = -v;
} else {
v = 0;
}
g->sb_hybrid[s_index++] = v;
if (y) {
if (y == 15)
y += get_bitsz(&s->gb, linbits);
v = l3_unscale(y, exponents[s_index]);
if (get_bits1(&s->gb))
v = -v;
} else {
v = 0;
}
g->sb_hybrid[s_index++] = v;
}
}
/* high frequencies */
vlc = &huff_quad_vlc[g->count1table_select];
last_buf_ptr = NULL;
last_bit_buf = 0;
last_bit_cnt = 0;
while (s_index <= 572) {
pos = get_bits_count(&s->gb);
if (pos >= end_pos) {
if (pos > end_pos && last_buf_ptr != NULL) {
/* some encoders generate an incorrect size for this
part. We must go back into the data */
s_index -= 4;
s->gb.buf_ptr = last_buf_ptr;
s->gb.bit_buf = last_bit_buf;
s->gb.bit_cnt = last_bit_cnt;
}
break;
}
last_buf_ptr = s->gb.buf_ptr;
last_bit_buf = s->gb.bit_buf;
last_bit_cnt = s->gb.bit_cnt;
code = get_vlc(&s->gb, vlc);
dprintf("t=%d code=%d\n", g->count1table_select, code);
if (code < 0)
return -1;
for(i=0;i<4;i++) {
if (code & (8 >> i)) {
/* non zero value. Could use a hand coded function for
'one' value */
v = l3_unscale(1, exponents[s_index]);
if(get_bits1(&s->gb))
v = -v;
} else {
v = 0;
}
g->sb_hybrid[s_index++] = v;
}
}
while (s_index < 576)
g->sb_hybrid[s_index++] = 0;
return 0;
}
/* Reorder short blocks from bitstream order to interleaved order. It
would be faster to do it in parsing, but the code would be far more
complicated */
static void reorder_block(MPADecodeContext *s, GranuleDef *g)
{
int i, j, k, len;
INT32 *ptr, *dst, *ptr1;
INT32 tmp[576];
if (g->block_type != 2)
return;
if (g->switch_point) {
if (s->sample_rate_index != 8) {
ptr = g->sb_hybrid + 36;
} else {
ptr = g->sb_hybrid + 48;
}
} else {
ptr = g->sb_hybrid;
}
for(i=g->short_start;i<13;i++) {
len = band_size_short[s->sample_rate_index][i];
ptr1 = ptr;
for(k=0;k<3;k++) {
dst = tmp + k;
for(j=len;j>0;j--) {
*dst = *ptr++;
dst += 3;
}
}
memcpy(ptr1, tmp, len * 3 * sizeof(INT32));
}
}
#define ISQRT2 FIXR(0.70710678118654752440)
static void compute_stereo(MPADecodeContext *s,
GranuleDef *g0, GranuleDef *g1)
{
int i, j, k, l;
INT32 v1, v2;
int sf_max, tmp0, tmp1, sf, len, non_zero_found;
INT32 (*is_tab)[16];
INT32 *tab0, *tab1;
int non_zero_found_short[3];
/* intensity stereo */
if (s->mode_ext & MODE_EXT_I_STEREO) {
if (!s->lsf) {
is_tab = is_table;
sf_max = 7;
} else {
is_tab = is_table_lsf[g1->scalefac_compress & 1];
sf_max = 16;
}
tab0 = g0->sb_hybrid + 576;
tab1 = g1->sb_hybrid + 576;
non_zero_found_short[0] = 0;
non_zero_found_short[1] = 0;
non_zero_found_short[2] = 0;
k = (13 - g1->short_start) * 3 + g1->long_end - 3;
for(i = 12;i >= g1->short_start;i--) {
/* for last band, use previous scale factor */
if (i != 11)
k -= 3;
len = band_size_short[s->sample_rate_index][i];
for(l=2;l>=0;l--) {
tab0 -= len;
tab1 -= len;
if (!non_zero_found_short[l]) {
/* test if non zero band. if so, stop doing i-stereo */
for(j=0;j<len;j++) {
if (tab1[j] != 0) {
non_zero_found_short[l] = 1;
goto found1;
}
}
sf = g1->scale_factors[k + l];
if (sf >= sf_max)
goto found1;
v1 = is_tab[0][sf];
v2 = is_tab[1][sf];
for(j=0;j<len;j++) {
tmp0 = tab0[j];
tab0[j] = MULL(tmp0, v1);
tab1[j] = MULL(tmp0, v2);
}
} else {
found1:
if (s->mode_ext & MODE_EXT_MS_STEREO) {
/* lower part of the spectrum : do ms stereo
if enabled */
for(j=0;j<len;j++) {
tmp0 = tab0[j];
tmp1 = tab1[j];
tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
}
}
}
}
}
non_zero_found = non_zero_found_short[0] |
non_zero_found_short[1] |
non_zero_found_short[2];
for(i = g1->long_end - 1;i >= 0;i--) {
len = band_size_long[s->sample_rate_index][i];
tab0 -= len;
tab1 -= len;
/* test if non zero band. if so, stop doing i-stereo */
if (!non_zero_found) {
for(j=0;j<len;j++) {
if (tab1[j] != 0) {
non_zero_found = 1;
goto found2;
}
}
/* for last band, use previous scale factor */
k = (i == 21) ? 20 : i;
sf = g1->scale_factors[k];
if (sf >= sf_max)
goto found2;
v1 = is_tab[0][sf];
v2 = is_tab[1][sf];
for(j=0;j<len;j++) {
tmp0 = tab0[j];
tab0[j] = MULL(tmp0, v1);
tab1[j] = MULL(tmp0, v2);
}
} else {
found2:
if (s->mode_ext & MODE_EXT_MS_STEREO) {
/* lower part of the spectrum : do ms stereo
if enabled */
for(j=0;j<len;j++) {
tmp0 = tab0[j];
tmp1 = tab1[j];
tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
}
}
}
}
} else if (s->mode_ext & MODE_EXT_MS_STEREO) {
/* ms stereo ONLY */
/* NOTE: the 1/sqrt(2) normalization factor is included in the
global gain */
tab0 = g0->sb_hybrid;
tab1 = g1->sb_hybrid;
for(i=0;i<576;i++) {
tmp0 = tab0[i];
tmp1 = tab1[i];
tab0[i] = tmp0 + tmp1;
tab1[i] = tmp0 - tmp1;
}
}
}
static void compute_antialias(MPADecodeContext *s,
GranuleDef *g)
{
INT32 *ptr, *p0, *p1, *csa;
int n, tmp0, tmp1, i, j;
/* we antialias only "long" bands */
if (g->block_type == 2) {
if (!g->switch_point)
return;
/* XXX: check this for 8000Hz case */
n = 1;
} else {
n = SBLIMIT - 1;
}
ptr = g->sb_hybrid + 18;
for(i = n;i > 0;i--) {
p0 = ptr - 1;
p1 = ptr;
csa = &csa_table[0][0];
for(j=0;j<8;j++) {
tmp0 = *p0;
tmp1 = *p1;
*p0 = FRAC_RND(MUL64(tmp0, csa[0]) - MUL64(tmp1, csa[1]));
*p1 = FRAC_RND(MUL64(tmp0, csa[1]) + MUL64(tmp1, csa[0]));
p0--;
p1++;
csa += 2;
}
ptr += 18;
}
}
static void compute_imdct(MPADecodeContext *s,
GranuleDef *g,
INT32 *sb_samples,
INT32 *mdct_buf)
{
INT32 *ptr, *win, *win1, *buf, *buf2, *out_ptr, *ptr1;
INT32 in[6];
INT32 out[36];
INT32 out2[12];
int i, j, k, mdct_long_end, v, sblimit;
/* find last non zero block */
ptr = g->sb_hybrid + 576;
ptr1 = g->sb_hybrid + 2 * 18;
while (ptr >= ptr1) {
ptr -= 6;
v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];
if (v != 0)
break;
}
sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
if (g->block_type == 2) {
/* XXX: check for 8000 Hz */
if (g->switch_point)
mdct_long_end = 2;
else
mdct_long_end = 0;
} else {
mdct_long_end = sblimit;
}
buf = mdct_buf;
ptr = g->sb_hybrid;
for(j=0;j<mdct_long_end;j++) {
imdct36(out, ptr);
/* apply window & overlap with previous buffer */
out_ptr = sb_samples + j;
/* select window */
if (g->switch_point && j < 2)
win1 = mdct_win[0];
else
win1 = mdct_win[g->block_type];
/* select frequency inversion */
win = win1 + ((4 * 36) & -(j & 1));
for(i=0;i<18;i++) {
*out_ptr = MULL(out[i], win[i]) + buf[i];
buf[i] = MULL(out[i + 18], win[i + 18]);
out_ptr += SBLIMIT;
}
ptr += 18;
buf += 18;
}
for(j=mdct_long_end;j<sblimit;j++) {
for(i=0;i<6;i++) {
out[i] = 0;
out[6 + i] = 0;
out[30+i] = 0;
}
/* select frequency inversion */
win = mdct_win[2] + ((4 * 36) & -(j & 1));
buf2 = out + 6;
for(k=0;k<3;k++) {
/* reorder input for short mdct */
ptr1 = ptr + k;
for(i=0;i<6;i++) {
in[i] = *ptr1;
ptr1 += 3;
}
imdct12(out2, in);
/* apply 12 point window and do small overlap */
for(i=0;i<6;i++) {
buf2[i] = MULL(out2[i], win[i]) + buf2[i];
buf2[i + 6] = MULL(out2[i + 6], win[i + 6]);
}
buf2 += 6;
}
/* overlap */
out_ptr = sb_samples + j;
for(i=0;i<18;i++) {
*out_ptr = out[i] + buf[i];
buf[i] = out[i + 18];
out_ptr += SBLIMIT;
}
ptr += 18;
buf += 18;
}
/* zero bands */
for(j=sblimit;j<SBLIMIT;j++) {
/* overlap */
out_ptr = sb_samples + j;
for(i=0;i<18;i++) {
*out_ptr = buf[i];
buf[i] = 0;
out_ptr += SBLIMIT;
}
buf += 18;
}
}
#ifdef DEBUG
void sample_dump(int fnum, INT32 *tab, int n)
{
static FILE *files[16], *f;
char buf[512];
f = files[fnum];
if (!f) {
sprintf(buf, "/tmp/out%d.pcm", fnum);
f = fopen(buf, "w");
if (!f)
return;
files[fnum] = f;
}
if (fnum == 0) {
int i;
static int pos = 0;
printf("pos=%d\n", pos);
for(i=0;i<n;i++) {
printf(" %f", (double)tab[i] / 32768.0);
if ((i % 18) == 17)
printf("\n");
}
pos += n;
}
fwrite(tab, 1, n * sizeof(INT32), f);
}
#endif
/* main layer3 decoding function */
static int mp_decode_layer3(MPADecodeContext *s)
{
int nb_granules, main_data_begin, private_bits;
int gr, ch, blocksplit_flag, i, j, k, n, bits_pos, bits_left;
GranuleDef granules[2][2], *g;
INT16 exponents[576];
/* read side info */
if (s->lsf) {
main_data_begin = get_bits(&s->gb, 8);
if (s->nb_channels == 2)
private_bits = get_bits(&s->gb, 2);
else
private_bits = get_bits(&s->gb, 1);
nb_granules = 1;
} else {
main_data_begin = get_bits(&s->gb, 9);
if (s->nb_channels == 2)
private_bits = get_bits(&s->gb, 3);
else
private_bits = get_bits(&s->gb, 5);
nb_granules = 2;
for(ch=0;ch<s->nb_channels;ch++) {
granules[ch][0].scfsi = 0; /* all scale factors are transmitted */
granules[ch][1].scfsi = get_bits(&s->gb, 4);
}
}
for(gr=0;gr<nb_granules;gr++) {
for(ch=0;ch<s->nb_channels;ch++) {
dprintf("gr=%d ch=%d: side_info\n", gr, ch);
g = &granules[ch][gr];
g->part2_3_length = get_bits(&s->gb, 12);
g->big_values = get_bits(&s->gb, 9);
g->global_gain = get_bits(&s->gb, 8);
/* if MS stereo only is selected, we precompute the
1/sqrt(2) renormalization factor */
if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
MODE_EXT_MS_STEREO)
g->global_gain -= 2;
if (s->lsf)
g->scalefac_compress = get_bits(&s->gb, 9);
else
g->scalefac_compress = get_bits(&s->gb, 4);
blocksplit_flag = get_bits(&s->gb, 1);
if (blocksplit_flag) {
g->block_type = get_bits(&s->gb, 2);
if (g->block_type == 0)
return -1;
g->switch_point = get_bits(&s->gb, 1);
for(i=0;i<2;i++)
g->table_select[i] = get_bits(&s->gb, 5);
for(i=0;i<3;i++)
g->subblock_gain[i] = get_bits(&s->gb, 3);
/* compute huffman coded region sizes */
if (g->block_type == 2)
g->region_size[0] = (36 / 2);
else {
if (s->sample_rate_index <= 2)
g->region_size[0] = (36 / 2);
else if (s->sample_rate_index != 8)
g->region_size[0] = (54 / 2);
else
g->region_size[0] = (108 / 2);
}
g->region_size[1] = (576 / 2);
} else {
int region_address1, region_address2, l;
g->block_type = 0;
g->switch_point = 0;
for(i=0;i<3;i++)
g->table_select[i] = get_bits(&s->gb, 5);
/* compute huffman coded region sizes */
region_address1 = get_bits(&s->gb, 4);
region_address2 = get_bits(&s->gb, 3);
dprintf("region1=%d region2=%d\n",
region_address1, region_address2);
g->region_size[0] =
band_index_long[s->sample_rate_index][region_address1 + 1] >> 1;
l = region_address1 + region_address2 + 2;
/* should not overflow */
if (l > 22)
l = 22;
g->region_size[1] =
band_index_long[s->sample_rate_index][l] >> 1;
}
/* convert region offsets to region sizes and truncate
size to big_values */
g->region_size[2] = (576 / 2);
j = 0;
for(i=0;i<3;i++) {
k = g->region_size[i];
if (k > g->big_values)
k = g->big_values;
g->region_size[i] = k - j;
j = k;
}
/* compute band indexes */
if (g->block_type == 2) {
if (g->switch_point) {
/* if switched mode, we handle the 36 first samples as
long blocks. For 8000Hz, we handle the 48 first
exponents as long blocks (XXX: check this!) */
if (s->sample_rate_index <= 2)
g->long_end = 8;
else if (s->sample_rate_index != 8)
g->long_end = 6;
else
g->long_end = 4; /* 8000 Hz */
if (s->sample_rate_index != 8)
g->short_start = 3;
else
g->short_start = 2;
} else {
g->long_end = 0;
g->short_start = 0;
}
} else {
g->short_start = 13;
g->long_end = 22;
}
g->preflag = 0;
if (!s->lsf)
g->preflag = get_bits(&s->gb, 1);
g->scalefac_scale = get_bits(&s->gb, 1);
g->count1table_select = get_bits(&s->gb, 1);
dprintf("block_type=%d switch_point=%d\n",
g->block_type, g->switch_point);
}
}
/* now we get bits from the main_data_begin offset */
dprintf("seekback: %d\n", main_data_begin);
seek_to_maindata(s, main_data_begin);
for(gr=0;gr<nb_granules;gr++) {
for(ch=0;ch<s->nb_channels;ch++) {
g = &granules[ch][gr];
bits_pos = get_bits_count(&s->gb);
if (!s->lsf) {
UINT8 *sc;
int slen, slen1, slen2;
/* MPEG1 scale factors */
slen1 = slen_table[0][g->scalefac_compress];
slen2 = slen_table[1][g->scalefac_compress];
dprintf("slen1=%d slen2=%d\n", slen1, slen2);
if (g->block_type == 2) {
n = g->switch_point ? 17 : 18;
j = 0;
for(i=0;i<n;i++)
g->scale_factors[j++] = get_bitsz(&s->gb, slen1);
for(i=0;i<18;i++)
g->scale_factors[j++] = get_bitsz(&s->gb, slen2);
for(i=0;i<3;i++)
g->scale_factors[j++] = 0;
} else {
sc = granules[ch][0].scale_factors;
j = 0;
for(k=0;k<4;k++) {
n = (k == 0 ? 6 : 5);
if ((g->scfsi & (0x8 >> k)) == 0) {
slen = (k < 2) ? slen1 : slen2;
for(i=0;i<n;i++)
g->scale_factors[j++] = get_bitsz(&s->gb, slen);
} else {
/* simply copy from last granule */
for(i=0;i<n;i++) {
g->scale_factors[j] = sc[j];
j++;
}
}
}
g->scale_factors[j++] = 0;
}
#ifdef DEBUG
{
printf("scfsi=%x gr=%d ch=%d scale_factors:\n",
g->scfsi, gr, ch);
for(i=0;i<j;i++)
printf(" %d", g->scale_factors[i]);
printf("\n");
}
#endif
} else {
int tindex, tindex2, slen[4], sl, sf;
/* LSF scale factors */
if (g->block_type == 2) {
tindex = g->switch_point ? 2 : 1;
} else {
tindex = 0;
}
sf = g->scalefac_compress;
if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
/* intensity stereo case */
sf >>= 1;
if (sf < 180) {
lsf_sf_expand(slen, sf, 6, 6, 0);
tindex2 = 3;
} else if (sf < 244) {
lsf_sf_expand(slen, sf - 180, 4, 4, 0);
tindex2 = 4;
} else {
lsf_sf_expand(slen, sf - 244, 3, 0, 0);
tindex2 = 5;
}
} else {
/* normal case */
if (sf < 400) {
lsf_sf_expand(slen, sf, 5, 4, 4);
tindex2 = 0;
} else if (sf < 500) {
lsf_sf_expand(slen, sf - 400, 5, 4, 0);
tindex2 = 1;
} else {
lsf_sf_expand(slen, sf - 500, 3, 0, 0);
tindex2 = 2;
g->preflag = 1;
}
}
j = 0;
for(k=0;k<4;k++) {
n = lsf_nsf_table[tindex2][tindex][k];
sl = slen[k];
for(i=0;i<n;i++)
g->scale_factors[j++] = get_bitsz(&s->gb, sl);
}
/* XXX: should compute exact size */
for(;j<40;j++)
g->scale_factors[j] = 0;
#ifdef DEBUG
{
printf("gr=%d ch=%d scale_factors:\n",
gr, ch);
for(i=0;i<40;i++)
printf(" %d", g->scale_factors[i]);
printf("\n");
}
#endif
}
exponents_from_scale_factors(s, g, exponents);
/* read Huffman coded residue */
if (huffman_decode(s, g, exponents,
bits_pos + g->part2_3_length) < 0)
return -1;
#if defined(DEBUG) && 0
sample_dump(3, g->sb_hybrid, 576);
#endif
/* skip extension bits */
bits_left = g->part2_3_length - (get_bits_count(&s->gb) - bits_pos);
if (bits_left < 0) {
dprintf("bits_left=%d\n", bits_left);
return -1;
}
while (bits_left >= 16) {
skip_bits(&s->gb, 16);
bits_left -= 16;
}
if (bits_left > 0)
skip_bits(&s->gb, bits_left);
} /* ch */
if (s->nb_channels == 2)
compute_stereo(s, &granules[0][gr], &granules[1][gr]);
for(ch=0;ch<s->nb_channels;ch++) {
g = &granules[ch][gr];
reorder_block(s, g);
#ifdef DEBUG
sample_dump(0, g->sb_hybrid, 576);
#endif
compute_antialias(s, g);
#ifdef DEBUG
sample_dump(1, g->sb_hybrid, 576);
#endif
compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
#ifdef DEBUG
sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);
#endif
}
} /* gr */
return nb_granules * 18;
}
static int mp_decode_frame(MPADecodeContext *s,
short *samples)
{
int i, nb_frames, ch;
short *samples_ptr;
init_get_bits(&s->gb, s->inbuf + HEADER_SIZE,
s->inbuf_ptr - s->inbuf - HEADER_SIZE);
/* skip error protection field */
if (s->error_protection)
get_bits(&s->gb, 16);
dprintf("frame %d:\n", s->frame_count);
switch(s->layer) {
case 1:
nb_frames = mp_decode_layer1(s);
break;
case 2:
nb_frames = mp_decode_layer2(s);
break;
case 3:
default:
nb_frames = mp_decode_layer3(s);
break;
}
#if defined(DEBUG)
for(i=0;i<nb_frames;i++) {
for(ch=0;ch<s->nb_channels;ch++) {
int j;
printf("%d-%d:", i, ch);
for(j=0;j<SBLIMIT;j++)
printf(" %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);
printf("\n");
}
}
#endif
/* apply the synthesis filter */
for(ch=0;ch<s->nb_channels;ch++) {
samples_ptr = samples + ch;
for(i=0;i<nb_frames;i++) {
synth_filter(s, ch, samples_ptr, s->nb_channels,
s->sb_samples[ch][i]);
samples_ptr += 32 * s->nb_channels;
}
}
#ifdef DEBUG
s->frame_count++;
#endif
return nb_frames * 32 * sizeof(short) * s->nb_channels;
}
static int decode_frame(AVCodecContext * avctx,
void *data, int *data_size,
UINT8 * buf, int buf_size)
......@@ -237,7 +2252,19 @@ static int decode_frame(AVCodecContext * avctx,
while (buf_size > 0) {
len = s->inbuf_ptr - s->inbuf;
if (s->frame_size == 0) {
/* no header seen : find one. We need at least 7 bytes to parse it */
/* special case for next header for first frame in free
format case (XXX: find a simpler method) */
if (s->free_format_next_header != 0) {
s->inbuf[0] = s->free_format_next_header >> 24;
s->inbuf[1] = s->free_format_next_header >> 16;
s->inbuf[2] = s->free_format_next_header >> 8;
s->inbuf[3] = s->free_format_next_header;
s->inbuf_ptr = s->inbuf + 4;
s->free_format_next_header = 0;
goto got_header;
}
/* no header seen : find one. We need at least HEADER_SIZE
bytes to parse it */
len = HEADER_SIZE - len;
if (len > buf_size)
len = buf_size;
......@@ -246,20 +2273,80 @@ static int decode_frame(AVCodecContext * avctx,
s->inbuf_ptr += len;
buf_size -= len;
if ((s->inbuf_ptr - s->inbuf) == HEADER_SIZE) {
got_header:
header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
(s->inbuf[2] << 8) | s->inbuf[3];
if (check_header(header) < 0) {
/* no sync found : move by one byte (inefficient, but simple!) */
memcpy(s->inbuf, s->inbuf + 1, HEADER_SIZE - 1);
s->inbuf_ptr--;
dprintf("skip %x\n", header);
/* reset free format frame size to give a chance
to get a new bitrate */
s->free_format_frame_size = 0;
} else {
decode_header(s, header);
/* update codec info */
avctx->sample_rate = s->sample_rate;
avctx->channels = s->mpstr.fr.stereo ? 2 : 1;
avctx->bit_rate = s->bit_rate;
if (decode_header(s, header) == 1) {
/* free format: compute frame size */
s->frame_size = -1;
} else {
/* update codec info */
avctx->sample_rate = s->sample_rate;
avctx->channels = s->nb_channels;
avctx->bit_rate = s->bit_rate;
}
}
}
} else if (s->frame_size == -1) {
/* free format : find next sync to compute frame size */
len = MPA_MAX_CODED_FRAME_SIZE - len;
if (len > buf_size)
len = buf_size;
if (len == 0) {
/* frame too long: resync */
s->frame_size = 0;
} else {
UINT8 *p, *pend;
UINT32 header1;
int padding;
memcpy(s->inbuf_ptr, buf_ptr, len);
/* check for header */
p = s->inbuf_ptr - 3;
pend = s->inbuf_ptr + len - 4;
while (p <= pend) {
header = (p[0] << 24) | (p[1] << 16) |
(p[2] << 8) | p[3];
header1 = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
(s->inbuf[2] << 8) | s->inbuf[3];
/* check with high probability that we have a
valid header */
if ((header & SAME_HEADER_MASK) ==
(header1 & SAME_HEADER_MASK)) {
/* header found: update pointers */
len = (p + 4) - s->inbuf_ptr;
buf_ptr += len;
buf_size -= len;
s->inbuf_ptr = p;
/* compute frame size */
s->free_format_next_header = header;
s->free_format_frame_size = s->inbuf_ptr - s->inbuf;
padding = (header1 >> 9) & 1;
if (s->layer == 1)
s->free_format_frame_size -= padding * 4;
else
s->free_format_frame_size -= padding;
dprintf("free frame size=%d padding=%d\n",
s->free_format_frame_size, padding);
decode_header(s, header1);
goto next_data;
}
p++;
}
/* not found: simply increase pointers */
buf_ptr += len;
s->inbuf_ptr += len;
buf_size -= len;
}
} else if (len < s->frame_size) {
len = s->frame_size - len;
if (len > buf_size)
......@@ -276,6 +2363,7 @@ static int decode_frame(AVCodecContext * avctx,
*data_size = out_size;
break;
}
next_data:
}
return buf_ptr - buf;
}
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment