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ffmpeg/libavcodec/mpegaudiodec.c
Roberto Togni d9b1c197e5 QDM2 compatible decoder 
Originally committed as revision 4649 to svn://svn.ffmpeg.org/ffmpeg/trunk
2005-10-18 20:16:43 +00:00

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/*
* MPEG Audio decoder
* Copyright (c) 2001, 2002 Fabrice Bellard.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* @file mpegaudiodec.c
* MPEG Audio decoder.
*/
//#define DEBUG
#include "avcodec.h"
#include "bitstream.h"
#include "dsputil.h"
/*
* 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 */
#ifdef CONFIG_MPEGAUDIO_HP
#define USE_HIGHPRECISION
#endif
#include "mpegaudio.h"
#define FRAC_ONE (1 << FRAC_BITS)
#define MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> FRAC_BITS)
#define MUL64(a,b) ((int64_t)(a) * (int64_t)(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)
#define FIXHR(a) ((int)((a) * (1LL<<32) + 0.5))
//#define MULH(a,b) (((int64_t)(a) * (int64_t)(b))>>32) //gcc 3.4 creates an incredibly bloated mess out of this
static always_inline int MULH(int a, int b){
return ((int64_t)(a) * (int64_t)(b))>>32;
}
/****************/
#define HEADER_SIZE 4
#define BACKSTEP_SIZE 512
struct GranuleDef;
typedef struct MPADecodeContext {
uint8_t inbuf1[2][MPA_MAX_CODED_FRAME_SIZE + BACKSTEP_SIZE]; /* input buffer */
int inbuf_index;
uint8_t *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_t 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] __attribute__((aligned(16)));
int synth_buf_offset[MPA_MAX_CHANNELS];
int32_t sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT] __attribute__((aligned(16)));
int32_t mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
#ifdef DEBUG
int frame_count;
#endif
void (*compute_antialias)(struct MPADecodeContext *s, struct GranuleDef *g);
int adu_mode; ///< 0 for standard mp3, 1 for adu formatted mp3
unsigned int dither_state;
} MPADecodeContext;
/**
* Context for MP3On4 decoder
*/
typedef struct MP3On4DecodeContext {
int frames; ///< number of mp3 frames per block (number of mp3 decoder instances)
int chan_cfg; ///< channel config number
MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance
} MP3On4DecodeContext;
/* layer 3 "granule" */
typedef struct GranuleDef {
uint8_t scfsi;
int part2_3_length;
int big_values;
int global_gain;
int scalefac_compress;
uint8_t block_type;
uint8_t switch_point;
int table_select[3];
int subblock_gain[3];
uint8_t scalefac_scale;
uint8_t 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_t scale_factors[40];
int32_t sb_hybrid[SBLIMIT * 18]; /* 576 samples */
} GranuleDef;
#define MODE_EXT_MS_STEREO 2
#define MODE_EXT_I_STEREO 1
/* layer 3 huffman tables */
typedef struct HuffTable {
int xsize;
const uint8_t *bits;
const uint16_t *codes;
} HuffTable;
#include "mpegaudiodectab.h"
static void compute_antialias_integer(MPADecodeContext *s, GranuleDef *g);
static void compute_antialias_float(MPADecodeContext *s, GranuleDef *g);
/* vlc structure for decoding layer 3 huffman tables */
static VLC huff_vlc[16];
static uint8_t *huff_code_table[16];
static VLC huff_quad_vlc[2];
/* computed from band_size_long */
static uint16_t band_index_long[9][23];
/* XXX: free when all decoders are closed */
#define TABLE_4_3_SIZE (8191 + 16)*4
static int8_t *table_4_3_exp;
static uint32_t *table_4_3_value;
/* intensity stereo coef table */
static int32_t is_table[2][16];
static int32_t is_table_lsf[2][2][16];
static int32_t csa_table[8][4];
static float csa_table_float[8][4];
static int32_t mdct_win[8][36];
/* lower 2 bits: modulo 3, higher bits: shift */
static uint16_t scale_factor_modshift[64];
/* [i][j]: 2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
static int32_t 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 const int32_t scale_factor_mult2[3][3] = {
SCALE_GEN(4.0 / 3.0), /* 3 steps */
SCALE_GEN(4.0 / 5.0), /* 5 steps */
SCALE_GEN(4.0 / 9.0), /* 9 steps */
};
void ff_mpa_synth_init(MPA_INT *window);
static MPA_INT window[512] __attribute__((aligned(16)));
/* 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_t 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;
/* NOTE: at this point, 1 <= shift >= 21 + 15 */
return (int)((val + (1LL << (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;
val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
/* NOTE: at this point, 0 <= shift <= 21 */
if (shift > 0)
val = (val + (1 << (shift - 1))) >> shift;
return val;
}
/* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
static inline int l3_unscale(int value, int exponent)
{
unsigned int m;
int e;
e = table_4_3_exp [4*value + (exponent&3)];
m = table_4_3_value[4*value + (exponent&3)];
e -= (exponent >> 2);
assert(e>=1);
if (e > 31)
return 0;
m = (m + (1 << (e-1))) >> e;
return m;
}
/* all integer n^(4/3) computation code */
#define DEV_ORDER 13
#define POW_FRAC_BITS 24
#define POW_FRAC_ONE (1 << POW_FRAC_BITS)
#define POW_FIX(a) ((int)((a) * POW_FRAC_ONE))
#define POW_MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> POW_FRAC_BITS)
static int dev_4_3_coefs[DEV_ORDER];
#if 0 /* unused */
static int pow_mult3[3] = {
POW_FIX(1.0),
POW_FIX(1.25992104989487316476),
POW_FIX(1.58740105196819947474),
};
#endif
static void int_pow_init(void)
{
int i, a;
a = POW_FIX(1.0);
for(i=0;i<DEV_ORDER;i++) {
a = POW_MULL(a, POW_FIX(4.0 / 3.0) - i * POW_FIX(1.0)) / (i + 1);
dev_4_3_coefs[i] = a;
}
}
#if 0 /* unused, remove? */
/* return the mantissa and the binary exponent */
static int int_pow(int i, int *exp_ptr)
{
int e, er, eq, j;
int a, a1;
/* renormalize */
a = i;
e = POW_FRAC_BITS;
while (a < (1 << (POW_FRAC_BITS - 1))) {
a = a << 1;
e--;
}
a -= (1 << POW_FRAC_BITS);
a1 = 0;
for(j = DEV_ORDER - 1; j >= 0; j--)
a1 = POW_MULL(a, dev_4_3_coefs[j] + a1);
a = (1 << POW_FRAC_BITS) + a1;
/* exponent compute (exact) */
e = e * 4;
er = e % 3;
eq = e / 3;
a = POW_MULL(a, pow_mult3[er]);
while (a >= 2 * POW_FRAC_ONE) {
a = a >> 1;
eq++;
}
/* convert to float */
while (a < POW_FRAC_ONE) {
a = a << 1;
eq--;
}
/* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */
#if POW_FRAC_BITS > FRAC_BITS
a = (a + (1 << (POW_FRAC_BITS - FRAC_BITS - 1))) >> (POW_FRAC_BITS - FRAC_BITS);
/* correct overflow */
if (a >= 2 * (1 << FRAC_BITS)) {
a = a >> 1;
eq++;
}
#endif
*exp_ptr = eq;
return a;
}
#endif
static int decode_init(AVCodecContext * avctx)
{
MPADecodeContext *s = avctx->priv_data;
static int init=0;
int i, j, k;
#if defined(USE_HIGHPRECISION) && defined(CONFIG_AUDIO_NONSHORT)
avctx->sample_fmt= SAMPLE_FMT_S32;
#else
avctx->sample_fmt= SAMPLE_FMT_S16;
#endif
if(avctx->antialias_algo != FF_AA_FLOAT)
s->compute_antialias= compute_antialias_integer;
else
s->compute_antialias= compute_antialias_float;
if (!init && !avctx->parse_only) {
/* 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);
mod = i % 3;
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_t_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
scale_factor_mult[i][0] = MULL(FIXR(1.0 * 2.0), norm);
scale_factor_mult[i][1] = MULL(FIXR(0.7937005259 * 2.0), norm);
scale_factor_mult[i][2] = MULL(FIXR(0.6299605249 * 2.0), 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]);
}
ff_mpa_synth_init(window);
/* huffman decode tables */
huff_code_table[0] = NULL;
for(i=1;i<16;i++) {
const HuffTable *h = &mpa_huff_tables[i];
int xsize, x, y;
unsigned int n;
uint8_t *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, 1);
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, 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_static(TABLE_4_3_SIZE * sizeof(table_4_3_exp[0]));
if(!table_4_3_exp)
return -1;
table_4_3_value= av_mallocz_static(TABLE_4_3_SIZE * sizeof(table_4_3_value[0]));
if(!table_4_3_value)
return -1;
int_pow_init();
for(i=1;i<TABLE_4_3_SIZE;i++) {
double f, fm;
int e, m;
f = pow((double)(i/4), 4.0 / 3.0) * pow(2, (i&3)*0.25);
fm = frexp(f, &e);
m = (uint32_t)(fm*(1LL<<31) + 0.5);
e+= FRAC_BITS - 31 + 5;
/* normalized to FRAC_BITS */
table_4_3_value[i] = m;
// av_log(NULL, AV_LOG_DEBUG, "%d %d %f\n", i, m, pow((double)i, 4.0 / 3.0));
table_4_3_exp[i] = -e;
}
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] = FIXHR(cs/4);
csa_table[i][1] = FIXHR(ca/4);
csa_table[i][2] = FIXHR(ca/4) + FIXHR(cs/4);
csa_table[i][3] = FIXHR(ca/4) - FIXHR(cs/4);
csa_table_float[i][0] = cs;
csa_table_float[i][1] = ca;
csa_table_float[i][2] = ca + cs;
csa_table_float[i][3] = ca - cs;
// printf("%d %d %d %d\n", FIX(cs), FIX(cs-1), FIX(ca), FIX(cs)-FIX(ca));
// av_log(NULL, AV_LOG_DEBUG,"%f %f %f %f\n", cs, ca, ca+cs, ca-cs);
}
/* compute mdct windows */
for(i=0;i<36;i++) {
for(j=0; j<4; j++){
double d;
if(j==2 && i%3 != 1)
continue;
d= sin(M_PI * (i + 0.5) / 36.0);
if(j==1){
if (i>=30) d= 0;
else if(i>=24) d= sin(M_PI * (i - 18 + 0.5) / 12.0);
else if(i>=18) d= 1;
}else if(j==3){
if (i< 6) d= 0;
else if(i< 12) d= sin(M_PI * (i - 6 + 0.5) / 12.0);
else if(i< 18) d= 1;
}
//merge last stage of imdct into the window coefficients
d*= 0.5 / cos(M_PI*(2*i + 19)/72);
if(j==2)
mdct_win[j][i/3] = FIXHR((d / (1<<5)));
else
mdct_win[j][i ] = FIXHR((d / (1<<5)));
// av_log(NULL, AV_LOG_DEBUG, "%2d %d %f\n", i,j,d / (1<<5));
}
}
/* 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;
}
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
if (avctx->codec_id == CODEC_ID_MP3ADU)
s->adu_mode = 1;
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_t *out, int32_t *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];
}
#if FRAC_BITS <= 15
static inline int round_sample(int *sum)
{
int sum1;
sum1 = (*sum) >> OUT_SHIFT;
*sum &= (1<<OUT_SHIFT)-1;
if (sum1 < OUT_MIN)
sum1 = OUT_MIN;
else if (sum1 > OUT_MAX)
sum1 = OUT_MAX;
return sum1;
}
#if defined(ARCH_POWERPC_405)
/* signed 16x16 -> 32 multiply add accumulate */
#define MACS(rt, ra, rb) \
asm ("maclhw %0, %2, %3" : "=r" (rt) : "0" (rt), "r" (ra), "r" (rb));
/* signed 16x16 -> 32 multiply */
#define MULS(ra, rb) \
({ int __rt; asm ("mullhw %0, %1, %2" : "=r" (__rt) : "r" (ra), "r" (rb)); __rt; })
#else
/* signed 16x16 -> 32 multiply add accumulate */
#define MACS(rt, ra, rb) rt += (ra) * (rb)
/* signed 16x16 -> 32 multiply */
#define MULS(ra, rb) ((ra) * (rb))
#endif
#else
static inline int round_sample(int64_t *sum)
{
int sum1;
sum1 = (int)((*sum) >> OUT_SHIFT);
*sum &= (1<<OUT_SHIFT)-1;
if (sum1 < OUT_MIN)
sum1 = OUT_MIN;
else if (sum1 > OUT_MAX)
sum1 = OUT_MAX;
return sum1;
}
#define MULS(ra, rb) MUL64(ra, rb)
#endif
#define SUM8(sum, op, w, p) \
{ \
sum op MULS((w)[0 * 64], p[0 * 64]);\
sum op MULS((w)[1 * 64], p[1 * 64]);\
sum op MULS((w)[2 * 64], p[2 * 64]);\
sum op MULS((w)[3 * 64], p[3 * 64]);\
sum op MULS((w)[4 * 64], p[4 * 64]);\
sum op MULS((w)[5 * 64], p[5 * 64]);\
sum op MULS((w)[6 * 64], p[6 * 64]);\
sum op MULS((w)[7 * 64], p[7 * 64]);\
}
#define SUM8P2(sum1, op1, sum2, op2, w1, w2, p) \
{ \
int tmp;\
tmp = p[0 * 64];\
sum1 op1 MULS((w1)[0 * 64], tmp);\
sum2 op2 MULS((w2)[0 * 64], tmp);\
tmp = p[1 * 64];\
sum1 op1 MULS((w1)[1 * 64], tmp);\
sum2 op2 MULS((w2)[1 * 64], tmp);\
tmp = p[2 * 64];\
sum1 op1 MULS((w1)[2 * 64], tmp);\
sum2 op2 MULS((w2)[2 * 64], tmp);\
tmp = p[3 * 64];\
sum1 op1 MULS((w1)[3 * 64], tmp);\
sum2 op2 MULS((w2)[3 * 64], tmp);\
tmp = p[4 * 64];\
sum1 op1 MULS((w1)[4 * 64], tmp);\
sum2 op2 MULS((w2)[4 * 64], tmp);\
tmp = p[5 * 64];\
sum1 op1 MULS((w1)[5 * 64], tmp);\
sum2 op2 MULS((w2)[5 * 64], tmp);\
tmp = p[6 * 64];\
sum1 op1 MULS((w1)[6 * 64], tmp);\
sum2 op2 MULS((w2)[6 * 64], tmp);\
tmp = p[7 * 64];\
sum1 op1 MULS((w1)[7 * 64], tmp);\
sum2 op2 MULS((w2)[7 * 64], tmp);\
}
void ff_mpa_synth_init(MPA_INT *window)
{
int i;
/* 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;
}
}
/* 32 sub band synthesis filter. Input: 32 sub band samples, Output:
32 samples. */
/* XXX: optimize by avoiding ring buffer usage */
void ff_mpa_synth_filter(MPA_INT *synth_buf_ptr, int *synth_buf_offset,
MPA_INT *window, int *dither_state,
OUT_INT *samples, int incr,
int32_t sb_samples[SBLIMIT])
{
int32_t tmp[32];
register MPA_INT *synth_buf;
register const MPA_INT *w, *w2, *p;
int j, offset, v;
OUT_INT *samples2;
#if FRAC_BITS <= 15
int sum, sum2;
#else
int64_t sum, sum2;
#endif
dct32(tmp, sb_samples);
offset = *synth_buf_offset;
synth_buf = synth_buf_ptr + offset;
for(j=0;j<32;j++) {
v = tmp[j];
#if FRAC_BITS <= 15
/* NOTE: can cause a loss in precision if very high amplitude
sound */
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));
samples2 = samples + 31 * incr;
w = window;
w2 = window + 31;
sum = *dither_state;
p = synth_buf + 16;
SUM8(sum, +=, w, p);
p = synth_buf + 48;
SUM8(sum, -=, w + 32, p);
*samples = round_sample(&sum);
samples += incr;
w++;
/* we calculate two samples at the same time to avoid one memory
access per two sample */
for(j=1;j<16;j++) {
sum2 = 0;
p = synth_buf + 16 + j;
SUM8P2(sum, +=, sum2, -=, w, w2, p);
p = synth_buf + 48 - j;
SUM8P2(sum, -=, sum2, -=, w + 32, w2 + 32, p);
*samples = round_sample(&sum);
samples += incr;
sum += sum2;
*samples2 = round_sample(&sum);
samples2 -= incr;
w++;
w2--;
}
p = synth_buf + 32;
SUM8(sum, -=, w + 32, p);
*samples = round_sample(&sum);
*dither_state= sum;
offset = (offset - 32) & 511;
*synth_buf_offset = offset;
}
#define C3 FIXHR(0.86602540378443864676/2)
/* 0.5 / cos(pi*(2*i+1)/36) */
static const int icos36[9] = {
FIXR(0.50190991877167369479),
FIXR(0.51763809020504152469), //0
FIXR(0.55168895948124587824),
FIXR(0.61038729438072803416),
FIXR(0.70710678118654752439), //1
FIXR(0.87172339781054900991),
FIXR(1.18310079157624925896),
FIXR(1.93185165257813657349), //2
FIXR(5.73685662283492756461),
};
/* 12 points IMDCT. We compute it "by hand" by factorizing obvious
cases. */
static void imdct12(int *out, int *in)
{
int in0, in1, in2, in3, in4, in5, t1, t2;
in0= in[0*3];
in1= in[1*3] + in[0*3];
in2= in[2*3] + in[1*3];
in3= in[3*3] + in[2*3];
in4= in[4*3] + in[3*3];
in5= in[5*3] + in[4*3];
in5 += in3;
in3 += in1;
in2= MULH(2*in2, C3);
in3= MULH(2*in3, C3);
t1 = in0 - in4;
t2 = MULL(in1 - in5, icos36[4]);
out[ 7]=
out[10]= t1 + t2;
out[ 1]=
out[ 4]= t1 - t2;
in0 += in4>>1;
in4 = in0 + in2;
in1 += in5>>1;
in5 = MULL(in1 + in3, icos36[1]);
out[ 8]=
out[ 9]= in4 + in5;
out[ 2]=
out[ 3]= in4 - in5;
in0 -= in2;
in1 = MULL(in1 - in3, icos36[7]);
out[ 0]=
out[ 5]= in0 - in1;
out[ 6]=
out[11]= in0 + in1;
}
/* cos(pi*i/18) */
#define C1 FIXHR(0.98480775301220805936/2)
#define C2 FIXHR(0.93969262078590838405/2)
#define C3 FIXHR(0.86602540378443864676/2)
#define C4 FIXHR(0.76604444311897803520/2)
#define C5 FIXHR(0.64278760968653932632/2)
#define C6 FIXHR(0.5/2)
#define C7 FIXHR(0.34202014332566873304/2)
#define C8 FIXHR(0.17364817766693034885/2)
/* using Lee like decomposition followed by hand coded 9 points DCT */
static void imdct36(int *out, int *buf, int *in, int *win)
{
int i, j, t0, t1, t2, t3, s0, s1, s2, s3;
int tmp[18], *tmp1, *in1;
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;
#if 0
//more accurate but slower
int64_t t0, t1, t2, t3;
t2 = in1[2*4] + in1[2*8] - in1[2*2];
t3 = (in1[2*0] + (int64_t)(in1[2*6]>>1))<<32;
t1 = in1[2*0] - in1[2*6];
tmp1[ 6] = t1 - (t2>>1);
tmp1[16] = t1 + t2;
t0 = MUL64(2*(in1[2*2] + in1[2*4]), C2);
t1 = MUL64( in1[2*4] - in1[2*8] , -2*C8);
t2 = MUL64(2*(in1[2*2] + in1[2*8]), -C4);
tmp1[10] = (t3 - t0 - t2) >> 32;
tmp1[ 2] = (t3 + t0 + t1) >> 32;
tmp1[14] = (t3 + t2 - t1) >> 32;
tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);
t2 = MUL64(2*(in1[2*1] + in1[2*5]), C1);
t3 = MUL64( in1[2*5] - in1[2*7] , -2*C7);
t0 = MUL64(2*in1[2*3], C3);
t1 = MUL64(2*(in1[2*1] + in1[2*7]), -C5);
tmp1[ 0] = (t2 + t3 + t0) >> 32;
tmp1[12] = (t2 + t1 - t0) >> 32;
tmp1[ 8] = (t3 - t1 - t0) >> 32;
#else
t2 = in1[2*4] + in1[2*8] - in1[2*2];
t3 = in1[2*0] + (in1[2*6]>>1);
t1 = in1[2*0] - in1[2*6];
tmp1[ 6] = t1 - (t2>>1);
tmp1[16] = t1 + t2;
t0 = MULH(2*(in1[2*2] + in1[2*4]), C2);
t1 = MULH( in1[2*4] - in1[2*8] , -2*C8);
t2 = MULH(2*(in1[2*2] + in1[2*8]), -C4);
tmp1[10] = t3 - t0 - t2;
tmp1[ 2] = t3 + t0 + t1;
tmp1[14] = t3 + t2 - t1;
tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);
t2 = MULH(2*(in1[2*1] + in1[2*5]), C1);
t3 = MULH( in1[2*5] - in1[2*7] , -2*C7);
t0 = MULH(2*in1[2*3], C3);
t1 = MULH(2*(in1[2*1] + in1[2*7]), -C5);
tmp1[ 0] = t2 + t3 + t0;
tmp1[12] = t2 + t1 - t0;
tmp1[ 8] = t3 - t1 - t0;
#endif
}
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 = s0 + s1;
t1 = s0 - s1;
out[(9 + j)*SBLIMIT] = MULH(t1, win[9 + j]) + buf[9 + j];
out[(8 - j)*SBLIMIT] = MULH(t1, win[8 - j]) + buf[8 - j];
buf[9 + j] = MULH(t0, win[18 + 9 + j]);
buf[8 - j] = MULH(t0, win[18 + 8 - j]);
t0 = s2 + s3;
t1 = s2 - s3;
out[(9 + 8 - j)*SBLIMIT] = MULH(t1, win[9 + 8 - j]) + buf[9 + 8 - j];
out[( j)*SBLIMIT] = MULH(t1, win[ j]) + buf[ j];
buf[9 + 8 - j] = MULH(t0, win[18 + 9 + 8 - j]);
buf[ + j] = MULH(t0, win[18 + j]);
i += 4;
}
s0 = tmp[16];
s1 = MULL(tmp[17], icos36[4]);
t0 = s0 + s1;
t1 = s0 - s1;
out[(9 + 4)*SBLIMIT] = MULH(t1, win[9 + 4]) + buf[9 + 4];
out[(8 - 4)*SBLIMIT] = MULH(t1, win[8 - 4]) + buf[8 - 4];
buf[9 + 4] = MULH(t0, win[18 + 9 + 4]);
buf[8 - 4] = MULH(t0, win[18 + 8 - 4]);
}
/* header decoding. MUST check the header before because no
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_t header)
{
int sample_rate, frame_size, mpeg25, padding;
int sample_rate_index, bitrate_index;
if (header & (1<<20)) {
s->lsf = (header & (1<<19)) ? 0 : 1;
mpeg25 = 0;
} else {
s->lsf = 1;
mpeg25 = 1;
}
s->layer = 4 - ((header >> 17) & 3);
/* extract frequency */
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;
s->sample_rate = sample_rate;
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;
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;
}
}
#if defined(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;
}
/* useful helper to get mpeg audio stream infos. Return -1 if error in
header, otherwise the coded frame size in bytes */
int mpa_decode_header(AVCodecContext *avctx, uint32_t head)
{
MPADecodeContext s1, *s = &s1;
memset( s, 0, sizeof(MPADecodeContext) );
if (ff_mpa_check_header(head) != 0)
return -1;
if (decode_header(s, head) != 0) {
return -1;
}
switch(s->layer) {
case 1:
avctx->frame_size = 384;
break;
case 2:
avctx->frame_size = 1152;
break;
default:
case 3:
if (s->lsf)
avctx->frame_size = 576;
else
avctx->frame_size = 1152;
break;
}
avctx->sample_rate = s->sample_rate;
avctx->channels = s->nb_channels;
avctx->bit_rate = s->bit_rate;
avctx->sub_id = s->layer;
return s->frame_size;
}
/* return the number of decoded frames */
static int mp_decode_layer1(MPADecodeContext *s)
{
int bound, i, v, n, ch, j, mant;
uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
uint8_t 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);
}
}
/* 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;
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;
}
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;
/* 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);
/* sanity check */
if( bound > sblimit ) 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;
}
#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)
*/
static void seek_to_maindata(MPADecodeContext *s, unsigned int backstep)
{
uint8_t *ptr;
/* compute current position in stream */
ptr = (uint8_t *)(s->gb.buffer + (get_bits_count(&s->gb)>>3));
/* copy old data before current one */
ptr -= backstep;
memcpy(ptr, s->inbuf1[s->inbuf_index ^ 1] +
BACKSTEP_SIZE + s->old_frame_size - backstep, backstep);
/* init get bits again */
init_get_bits(&s->gb, ptr, (s->frame_size + backstep)*8);
/* 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_t *exponents)
{
const uint8_t *bstab, *pretab;
int len, i, j, k, l, v0, shift, gain, gains[3];
int16_t *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_t *exponents, int end_pos)
{
int s_index;
int linbits, code, x, y, l, v, i, j, k, pos;
GetBitContext last_gb;
VLC *vlc;
uint8_t *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_gb.buffer = NULL;
while (s_index <= 572) {
pos = get_bits_count(&s->gb);
if (pos >= end_pos) {
if (pos > end_pos && last_gb.buffer != NULL) {
/* some encoders generate an incorrect size for this
part. We must go back into the data */
s_index -= 4;
s->gb = last_gb;
}
break;
}
last_gb= s->gb;
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_t *ptr, *dst, *ptr1;
int32_t 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_t));
}
}
#define ISQRT2 FIXR(0.70710678118654752440)
static void compute_stereo(MPADecodeContext *s,
GranuleDef *g0, GranuleDef *g1)
{
int i, j, k, l;
int32_t v1, v2;
int sf_max, tmp0, tmp1, sf, len, non_zero_found;
int32_t (*is_tab)[16];
int32_t *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_integer(MPADecodeContext *s,
GranuleDef *g)
{
int32_t *ptr, *csa;
int n, i;
/* 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--) {
int tmp0, tmp1, tmp2;
csa = &csa_table[0][0];
#define INT_AA(j) \
tmp0 = ptr[-1-j];\
tmp1 = ptr[ j];\
tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\
ptr[-1-j] = 4*(tmp2 - MULH(tmp1, csa[2+4*j]));\
ptr[ j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j]));
INT_AA(0)
INT_AA(1)
INT_AA(2)
INT_AA(3)
INT_AA(4)
INT_AA(5)
INT_AA(6)
INT_AA(7)
ptr += 18;
}
}
static void compute_antialias_float(MPADecodeContext *s,
GranuleDef *g)
{
int32_t *ptr;
int n, i;
/* 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--) {
float tmp0, tmp1;
float *csa = &csa_table_float[0][0];
#define FLOAT_AA(j)\
tmp0= ptr[-1-j];\
tmp1= ptr[ j];\
ptr[-1-j] = lrintf(tmp0 * csa[0+4*j] - tmp1 * csa[1+4*j]);\
ptr[ j] = lrintf(tmp0 * csa[1+4*j] + tmp1 * csa[0+4*j]);
FLOAT_AA(0)
FLOAT_AA(1)
FLOAT_AA(2)
FLOAT_AA(3)
FLOAT_AA(4)
FLOAT_AA(5)
FLOAT_AA(6)
FLOAT_AA(7)
ptr += 18;
}
}
static void compute_imdct(MPADecodeContext *s,
GranuleDef *g,
int32_t *sb_samples,
int32_t *mdct_buf)
{
int32_t *ptr, *win, *win1, *buf, *out_ptr, *ptr1;
int32_t out2[12];
int i, j, 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++) {
/* 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));
imdct36(out_ptr, buf, ptr, win);
out_ptr += 18*SBLIMIT;
ptr += 18;
buf += 18;
}
for(j=mdct_long_end;j<sblimit;j++) {
/* select frequency inversion */
win = mdct_win[2] + ((4 * 36) & -(j & 1));
out_ptr = sb_samples + j;
for(i=0; i<6; i++){
*out_ptr = buf[i];
out_ptr += SBLIMIT;
}
imdct12(out2, ptr + 0);
for(i=0;i<6;i++) {
*out_ptr = MULH(out2[i], win[i]) + buf[i + 6*1];
buf[i + 6*2] = MULH(out2[i + 6], win[i + 6]);
out_ptr += SBLIMIT;
}
imdct12(out2, ptr + 1);
for(i=0;i<6;i++) {
*out_ptr = MULH(out2[i], win[i]) + buf[i + 6*2];
buf[i + 6*0] = MULH(out2[i + 6], win[i + 6]);
out_ptr += SBLIMIT;
}
imdct12(out2, ptr + 2);
for(i=0;i<6;i++) {
buf[i + 6*0] = MULH(out2[i], win[i]) + buf[i + 6*0];
buf[i + 6*1] = MULH(out2[i + 6], win[i + 6]);
buf[i + 6*2] = 0;
}
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;
}
}
#if defined(DEBUG)
void sample_dump(int fnum, int32_t *tab, int n)
{
static FILE *files[16], *f;
char buf[512];
int i;
int32_t v;
f = files[fnum];
if (!f) {
snprintf(buf, sizeof(buf), "/tmp/out%d.%s.pcm",
fnum,
#ifdef USE_HIGHPRECISION
"hp"
#else
"lp"
#endif
);
f = fopen(buf, "w");
if (!f)
return;
files[fnum] = f;
}
if (fnum == 0) {
static int pos = 0;
av_log(NULL, AV_LOG_DEBUG, "pos=%d\n", pos);
for(i=0;i<n;i++) {
av_log(NULL, AV_LOG_DEBUG, " %0.4f", (double)tab[i] / FRAC_ONE);
if ((i % 18) == 17)
av_log(NULL, AV_LOG_DEBUG, "\n");
}
pos += n;
}
for(i=0;i<n;i++) {
/* normalize to 23 frac bits */
v = tab[i] << (23 - FRAC_BITS);
fwrite(&v, 1, sizeof(int32_t), 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_t 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);
}
}
if (!s->adu_mode) {
/* 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_t *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;
}
#if defined(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;
#if defined(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)
sample_dump(0, 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);
#if defined(DEBUG)
sample_dump(0, g->sb_hybrid, 576);
#endif
s->compute_antialias(s, g);
#if defined(DEBUG)
sample_dump(1, g->sb_hybrid, 576);
#endif
compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
#if defined(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,
OUT_INT *samples)
{
int i, nb_frames, ch;
OUT_INT *samples_ptr;
init_get_bits(&s->gb, s->inbuf + HEADER_SIZE,
(s->inbuf_ptr - s->inbuf - HEADER_SIZE)*8);
/* 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++) {
ff_mpa_synth_filter(s->synth_buf[ch], &(s->synth_buf_offset[ch]),
window, &s->dither_state,
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(OUT_INT) * s->nb_channels;
}
static int decode_frame(AVCodecContext * avctx,
void *data, int *data_size,
uint8_t * buf, int buf_size)
{
MPADecodeContext *s = avctx->priv_data;
uint32_t header;
uint8_t *buf_ptr;
int len, out_size;
OUT_INT *out_samples = data;
buf_ptr = buf;
while (buf_size > 0) {
len = s->inbuf_ptr - s->inbuf;
if (s->frame_size == 0) {
/* 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;
if (len > 0) {
memcpy(s->inbuf_ptr, buf_ptr, len);
buf_ptr += len;
buf_size -= len;
s->inbuf_ptr += 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 (ff_mpa_check_header(header) < 0) {
/* no sync found : move by one byte (inefficient, but simple!) */
memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 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 {
if (decode_header(s, header) == 1) {
/* free format: prepare to compute frame size */
s->frame_size = -1;
}
/* update codec info */
avctx->sample_rate = s->sample_rate;
avctx->channels = s->nb_channels;
avctx->bit_rate = s->bit_rate;
avctx->sub_id = s->layer;
switch(s->layer) {
case 1:
avctx->frame_size = 384;
break;
case 2:
avctx->frame_size = 1152;
break;
case 3:
if (s->lsf)
avctx->frame_size = 576;
else
avctx->frame_size = 1152;
break;
}
}
}
} 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;
memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
s->inbuf_ptr--;
} else {
uint8_t *p, *pend;
uint32_t 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) {
if (s->frame_size > MPA_MAX_CODED_FRAME_SIZE)
s->frame_size = MPA_MAX_CODED_FRAME_SIZE;
len = s->frame_size - len;
if (len > buf_size)
len = buf_size;
memcpy(s->inbuf_ptr, buf_ptr, len);
buf_ptr += len;
s->inbuf_ptr += len;
buf_size -= len;
}
next_data:
if (s->frame_size > 0 &&
(s->inbuf_ptr - s->inbuf) >= s->frame_size) {
if (avctx->parse_only) {
/* simply return the frame data */
*(uint8_t **)data = s->inbuf;
out_size = s->inbuf_ptr - s->inbuf;
} else {
out_size = mp_decode_frame(s, out_samples);
}
s->inbuf_ptr = s->inbuf;
s->frame_size = 0;
if(out_size>=0)
*data_size = out_size;
else
av_log(avctx, AV_LOG_DEBUG, "Error while decoding mpeg audio frame\n"); //FIXME return -1 / but also return the number of bytes consumed
break;
}
}
return buf_ptr - buf;
}
static int decode_frame_adu(AVCodecContext * avctx,
void *data, int *data_size,
uint8_t * buf, int buf_size)
{
MPADecodeContext *s = avctx->priv_data;
uint32_t header;
int len, out_size;
OUT_INT *out_samples = data;
len = buf_size;
// Discard too short frames
if (buf_size < HEADER_SIZE) {
*data_size = 0;
return buf_size;
}
if (len > MPA_MAX_CODED_FRAME_SIZE)
len = MPA_MAX_CODED_FRAME_SIZE;
memcpy(s->inbuf, buf, len);
s->inbuf_ptr = s->inbuf + len;
// Get header and restore sync word
header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
(s->inbuf[2] << 8) | s->inbuf[3] | 0xffe00000;
if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame
*data_size = 0;
return buf_size;
}
decode_header(s, header);
/* update codec info */
avctx->sample_rate = s->sample_rate;
avctx->channels = s->nb_channels;
avctx->bit_rate = s->bit_rate;
avctx->sub_id = s->layer;
avctx->frame_size=s->frame_size = len;
if (avctx->parse_only) {
/* simply return the frame data */
*(uint8_t **)data = s->inbuf;
out_size = s->inbuf_ptr - s->inbuf;
} else {
out_size = mp_decode_frame(s, out_samples);
}
*data_size = out_size;
return buf_size;
}
/* Next 3 arrays are indexed by channel config number (passed via codecdata) */
static int mp3Frames[16] = {0,1,1,2,3,3,4,5,2}; /* number of mp3 decoder instances */
static int mp3Channels[16] = {0,1,2,3,4,5,6,8,4}; /* total output channels */
/* offsets into output buffer, assume output order is FL FR BL BR C LFE */
static int chan_offset[9][5] = {
{0},
{0}, // C
{0}, // FLR
{2,0}, // C FLR
{2,0,3}, // C FLR BS
{4,0,2}, // C FLR BLRS
{4,0,2,5}, // C FLR BLRS LFE
{4,0,2,6,5}, // C FLR BLRS BLR LFE
{0,2} // FLR BLRS
};
static int decode_init_mp3on4(AVCodecContext * avctx)
{
MP3On4DecodeContext *s = avctx->priv_data;
int i;
if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {
av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");
return -1;
}
s->chan_cfg = (((unsigned char *)avctx->extradata)[1] >> 3) & 0x0f;
s->frames = mp3Frames[s->chan_cfg];
if(!s->frames) {
av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");
return -1;
}
avctx->channels = mp3Channels[s->chan_cfg];
/* Init the first mp3 decoder in standard way, so that all tables get builded
* We replace avctx->priv_data with the context of the first decoder so that
* decode_init() does not have to be changed.
* Other decoders will be inited here copying data from the first context
*/
// Allocate zeroed memory for the first decoder context
s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));
// Put decoder context in place to make init_decode() happy
avctx->priv_data = s->mp3decctx[0];
decode_init(avctx);
// Restore mp3on4 context pointer
avctx->priv_data = s;
s->mp3decctx[0]->adu_mode = 1; // Set adu mode
/* Create a separate codec/context for each frame (first is already ok).
* Each frame is 1 or 2 channels - up to 5 frames allowed
*/
for (i = 1; i < s->frames; i++) {
s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));
s->mp3decctx[i]->compute_antialias = s->mp3decctx[0]->compute_antialias;
s->mp3decctx[i]->inbuf = &s->mp3decctx[i]->inbuf1[0][BACKSTEP_SIZE];
s->mp3decctx[i]->inbuf_ptr = s->mp3decctx[i]->inbuf;
s->mp3decctx[i]->adu_mode = 1;
}
return 0;
}
static int decode_close_mp3on4(AVCodecContext * avctx)
{
MP3On4DecodeContext *s = avctx->priv_data;
int i;
for (i = 0; i < s->frames; i++)
if (s->mp3decctx[i])
av_free(s->mp3decctx[i]);
return 0;
}
static int decode_frame_mp3on4(AVCodecContext * avctx,
void *data, int *data_size,
uint8_t * buf, int buf_size)
{
MP3On4DecodeContext *s = avctx->priv_data;
MPADecodeContext *m;
int len, out_size = 0;
uint32_t header;
OUT_INT *out_samples = data;
OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS];
OUT_INT *outptr, *bp;
int fsize;
unsigned char *start2 = buf, *start;
int fr, i, j, n;
int off = avctx->channels;
int *coff = chan_offset[s->chan_cfg];
len = buf_size;
// Discard too short frames
if (buf_size < HEADER_SIZE) {
*data_size = 0;
return buf_size;
}
// If only one decoder interleave is not needed
outptr = s->frames == 1 ? out_samples : decoded_buf;
for (fr = 0; fr < s->frames; fr++) {
start = start2;
fsize = (start[0] << 4) | (start[1] >> 4);
start2 += fsize;
if (fsize > len)
fsize = len;
len -= fsize;
if (fsize > MPA_MAX_CODED_FRAME_SIZE)
fsize = MPA_MAX_CODED_FRAME_SIZE;
m = s->mp3decctx[fr];
assert (m != NULL);
/* copy original to new */
m->inbuf_ptr = m->inbuf + fsize;
memcpy(m->inbuf, start, fsize);
// Get header
header = (m->inbuf[0] << 24) | (m->inbuf[1] << 16) |
(m->inbuf[2] << 8) | m->inbuf[3] | 0xfff00000;
if (ff_mpa_check_header(header) < 0) { // Bad header, discard block
*data_size = 0;
return buf_size;
}
decode_header(m, header);
mp_decode_frame(m, decoded_buf);
n = MPA_FRAME_SIZE * m->nb_channels;
out_size += n * sizeof(OUT_INT);
if(s->frames > 1) {
/* interleave output data */
bp = out_samples + coff[fr];
if(m->nb_channels == 1) {
for(j = 0; j < n; j++) {
*bp = decoded_buf[j];
bp += off;
}
} else {
for(j = 0; j < n; j++) {
bp[0] = decoded_buf[j++];
bp[1] = decoded_buf[j];
bp += off;
}
}
}
}
/* update codec info */
avctx->sample_rate = s->mp3decctx[0]->sample_rate;
avctx->frame_size= buf_size;
avctx->bit_rate = 0;
for (i = 0; i < s->frames; i++)
avctx->bit_rate += s->mp3decctx[i]->bit_rate;
*data_size = out_size;
return buf_size;
}
AVCodec mp2_decoder =
{
"mp2",
CODEC_TYPE_AUDIO,
CODEC_ID_MP2,
sizeof(MPADecodeContext),
decode_init,
NULL,
NULL,
decode_frame,
CODEC_CAP_PARSE_ONLY,
};
AVCodec mp3_decoder =
{
"mp3",
CODEC_TYPE_AUDIO,
CODEC_ID_MP3,
sizeof(MPADecodeContext),
decode_init,
NULL,
NULL,
decode_frame,
CODEC_CAP_PARSE_ONLY,
};
AVCodec mp3adu_decoder =
{
"mp3adu",
CODEC_TYPE_AUDIO,
CODEC_ID_MP3ADU,
sizeof(MPADecodeContext),
decode_init,
NULL,
NULL,
decode_frame_adu,
CODEC_CAP_PARSE_ONLY,
};
AVCodec mp3on4_decoder =
{
"mp3on4",
CODEC_TYPE_AUDIO,
CODEC_ID_MP3ON4,
sizeof(MP3On4DecodeContext),
decode_init_mp3on4,
NULL,
decode_close_mp3on4,
decode_frame_mp3on4,
0
};
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