libavcodec/mpegaudiodec.c File Reference

MPEG Audio decoder. More...

#include "libavutil/audioconvert.h"
#include "libavutil/avassert.h"
#include "libavutil/libm.h"
#include "avcodec.h"
#include "get_bits.h"
#include "mathops.h"
#include "mpegaudiodsp.h"
#include "dsputil.h"
#include "mpegaudio.h"
#include "mpegaudiodecheader.h"
#include "mpegaudiodata.h"
#include "mpegaudiodectab.h"
#include "mpegaudio_tablegen.h"

Go to the source code of this file.

Data Structures

struct  GranuleDef
struct  MPADecodeContext

Defines

#define BACKSTEP_SIZE   512
#define EXTRABYTES   24
#define LAST_BUF_SIZE   2 * BACKSTEP_SIZE + EXTRABYTES
#define SHR(a, b)   ((a)>>(b))
#define FIXR_OLD(a)   ((int)((a) * FRAC_ONE + 0.5))
#define FIXR(a)   ((int)((a) * FRAC_ONE + 0.5))
#define FIXHR(a)   ((int)((a) * (1LL<<32) + 0.5))
#define MULH3(x, y, s)   MULH((s)*(x), y)
#define MULLx(x, y, s)   MULL(x,y,s)
#define RENAME(a)   a ## _fixed
#define OUT_FMT   AV_SAMPLE_FMT_S16
#define HEADER_SIZE   4
#define SCALE_GEN(v)   { FIXR_OLD(1.0 * (v)), FIXR_OLD(0.7937005259 * (v)), FIXR_OLD(0.6299605249 * (v)) }
#define C3   FIXHR(0.86602540378443864676/2)
#define C4   FIXHR(0.70710678118654752439/2)
#define C5   FIXHR(0.51763809020504152469/2)
#define C6   FIXHR(1.93185165257813657349/4)
#define SPLIT(dst, sf, n)
#define READ_FLIP_SIGN(dst, src)
#define ISQRT2   FIXR(0.70710678118654752440)
#define AA(j)

Functions

static void ff_region_offset2size (GranuleDef *g)
 Convert region offsets to region sizes and truncate size to big_values.
static void ff_init_short_region (MPADecodeContext *s, GranuleDef *g)
static void ff_init_long_region (MPADecodeContext *s, GranuleDef *g, int ra1, int ra2)
static void ff_compute_band_indexes (MPADecodeContext *s, GranuleDef *g)
static int l1_unscale (int n, int mant, int scale_factor)
static int l2_unscale_group (int steps, int mant, int scale_factor)
static int l3_unscale (int value, int exponent)
static av_cold void decode_init_static (void)
static av_cold int decode_init (AVCodecContext *avctx)
static void imdct12 (INTFLOAT *out, INTFLOAT *in)
static int mp_decode_layer1 (MPADecodeContext *s)
static int mp_decode_layer2 (MPADecodeContext *s)
static av_always_inline void lsf_sf_expand (int *slen, int sf, int n1, int n2, int n3)
static void exponents_from_scale_factors (MPADecodeContext *s, GranuleDef *g, int16_t *exponents)
static int get_bitsz (GetBitContext *s, int n)
static void switch_buffer (MPADecodeContext *s, int *pos, int *end_pos, int *end_pos2)
static int huffman_decode (MPADecodeContext *s, GranuleDef *g, int16_t *exponents, int end_pos2)
static void reorder_block (MPADecodeContext *s, GranuleDef *g)
static void compute_stereo (MPADecodeContext *s, GranuleDef *g0, GranuleDef *g1)
static void compute_antialias (MPADecodeContext *s, GranuleDef *g)
static void compute_imdct (MPADecodeContext *s, GranuleDef *g, INTFLOAT *sb_samples, INTFLOAT *mdct_buf)
static int mp_decode_layer3 (MPADecodeContext *s)
static int mp_decode_frame (MPADecodeContext *s, OUT_INT *samples, const uint8_t *buf, int buf_size)
static int decode_frame (AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
static void flush (AVCodecContext *avctx)

Variables

static VLC huff_vlc [16]
static VLC_TYPE huff_vlc_tables [0+128+128+128+130+128+154+166+142+204+190+170+542+460+662+414][2]
static const int huff_vlc_tables_sizes [16]
static VLC huff_quad_vlc [2]
static VLC_TYPE huff_quad_vlc_tables [128+16][2]
static const int huff_quad_vlc_tables_sizes [2] = { 128, 16 }
static uint16_t band_index_long [9][23]
static INTFLOAT is_table [2][16]
static INTFLOAT is_table_lsf [2][2][16]
static INTFLOAT csa_table [8][4]
static int16_t division_tab3 [1<< 6]
static int16_t division_tab5 [1<< 8]
static int16_t division_tab9 [1<< 11]
static int16_t *const division_tabs [4]
static uint16_t scale_factor_modshift [64]
static int32_t scale_factor_mult [15][3]
static const int32_t scale_factor_mult2 [3][3]

Detailed Description

MPEG Audio decoder.

Definition in file mpegaudiodec.c.

Define Documentation

#define AA ( j   ) 

Value:

do {                                              \
        int tmp0 = ptr[-1-j];                                   \
        int tmp1 = ptr[   j];                                   \
        int tmp2 = MULH(tmp0 + tmp1, csa_table[j][0]);          \
        ptr[-1-j] = 4 * (tmp2 - MULH(tmp1, csa_table[j][2]));   \
        ptr[   j] = 4 * (tmp2 + MULH(tmp0, csa_table[j][3]));   \
    } while (0)

Definition at line 1196 of file mpegaudiodec.c.

Referenced by compute_antialias(), and overlay_ass_image().

#define BACKSTEP_SIZE   512

Definition at line 44 of file mpegaudiodec.c.

Referenced by mp_decode_frame().

#define C3   FIXHR(0.86602540378443864676/2)

Definition at line 454 of file mpegaudiodec.c.

Referenced by idct4col_add(), imdct12(), and imdct36().

#define C4   FIXHR(0.70710678118654752439/2)

Definition at line 455 of file mpegaudiodec.c.

Referenced by imdct12(), and imdct36().

#define C5   FIXHR(0.51763809020504152469/2)

Definition at line 456 of file mpegaudiodec.c.

Referenced by imdct12(), and imdct36().

#define C6   FIXHR(1.93185165257813657349/4)

Definition at line 457 of file mpegaudiodec.c.

Referenced by imdct12().

#define EXTRABYTES   24

Definition at line 45 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

#define FIXHR ( a   )     ((int)((a) * (1LL<<32) + 0.5))

Definition at line 104 of file mpegaudiodec.c.

#define FIXR ( a   )     ((int)((a) * FRAC_ONE + 0.5))

Definition at line 103 of file mpegaudiodec.c.

Referenced by decode_init_static().

#define FIXR_OLD ( a   )     ((int)((a) * FRAC_ONE + 0.5))

Definition at line 102 of file mpegaudiodec.c.

#define HEADER_SIZE   4

Definition at line 113 of file mpegaudiodec.c.

#define ISQRT2   FIXR(0.70710678118654752440)

Definition at line 1047 of file mpegaudiodec.c.

Referenced by compute_stereo().

#define LAST_BUF_SIZE   2 * BACKSTEP_SIZE + EXTRABYTES

Definition at line 46 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

#define MULH3 ( x,
y,
s   )     MULH((s)*(x), y)

Definition at line 105 of file mpegaudiodec.c.

#define MULLx ( x,
y,
s   )     MULL(x,y,s)

Definition at line 106 of file mpegaudiodec.c.

Referenced by compute_stereo(), decode_init_static(), and imdct36().

#define OUT_FMT   AV_SAMPLE_FMT_S16

Definition at line 108 of file mpegaudiodec.c.

Referenced by decode_init().

#define READ_FLIP_SIGN ( dst,
src   ) 

Value:

v      = -get_bits1(&s->gb);    \
    *(dst) = (*(src) ^ v) - v;

Definition at line 853 of file mpegaudiodec.c.

Referenced by huffman_decode().

#define RENAME ( a   )     a ## _fixed

Definition at line 107 of file mpegaudiodec.c.

Referenced by compute_imdct(), decode_init_static(), ff_imdct36_blocks_TMPL(), ff_init_mpadsp_tabs_TMPL(), get_mix_any_func_TMPL(), huffman_decode(), mp_decode_frame(), postProcess_TMPL(), rgb2rgb_init_TMPL(), sws_init_swScale_TMPL(), uyvytoyuv420_TMPL(), uyvytoyuv422_TMPL(), yuv422ptouyvy_TMPL(), yuv422ptoyuy2_TMPL(), yuyvtoyuv420_TMPL(), yuyvtoyuv422_TMPL(), yv12touyvy_TMPL(), and yv12toyuy2_TMPL().

#define SCALE_GEN ( v   )     { FIXR_OLD(1.0 * (v)), FIXR_OLD(0.7937005259 * (v)), FIXR_OLD(0.6299605249 * (v)) }

Definition at line 153 of file mpegaudiodec.c.

#define SHR ( a,
b   )     ((a)>>(b))

Definition at line 100 of file mpegaudiodec.c.

Referenced by imdct12(), and imdct36().

#define SPLIT ( dst,
sf,
n   ) 

Value:

if (n == 3) {                   \
        int m = (sf * 171) >> 9;    \
        dst   = sf - 3 * m;         \
        sf    = m;                  \
    } else if (n == 4) {            \
        dst  = sf & 3;              \
        sf >>= 2;                   \
    } else if (n == 5) {            \
        int m = (sf * 205) >> 10;   \
        dst   = sf - 5 * m;         \
        sf    = m;                  \
    } else if (n == 6) {            \
        int m = (sf * 171) >> 10;   \
        dst   = sf - 6 * m;         \
        sf    = m;                  \
    } else {                        \
        dst = 0;                    \
    }

Definition at line 755 of file mpegaudiodec.c.

Referenced by avfilter_register_all(), and lsf_sf_expand().

Function Documentation

static void compute_antialias ( MPADecodeContext *  s,
GranuleDef *  g 
) [static]

Definition at line 1205 of file mpegaudiodec.c.

static void compute_imdct ( MPADecodeContext *  s,
GranuleDef *  g,
INTFLOAT *  sb_samples,
INTFLOAT *  mdct_buf 
) [static]

Definition at line 1236 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

static void compute_stereo ( MPADecodeContext *  s,
GranuleDef *  g0,
GranuleDef *  g1 
) [static]

Definition at line 1049 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

static int decode_frame ( AVCodecContext *  avctx,
void *  data,
int *  got_frame_ptr,
AVPacket *  avpkt 
) [static]

Definition at line 1649 of file mpegaudiodec.c.

static av_cold int decode_init ( AVCodecContext *  avctx  )  [static]

Definition at line 427 of file mpegaudiodec.c.

static av_cold void decode_init_static ( void   )  [static]

Definition at line 278 of file mpegaudiodec.c.

Referenced by decode_init().

static void exponents_from_scale_factors ( MPADecodeContext *  s,
GranuleDef *  g,
int16_t *  exponents 
) [static]

Definition at line 784 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

static void ff_compute_band_indexes ( MPADecodeContext *  s,
GranuleDef *  g 
) [static]

Definition at line 204 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

static void ff_init_long_region ( MPADecodeContext *  s,
GranuleDef *  g,
int  ra1,
int  ra2 
) [static]

Definition at line 195 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

static void ff_init_short_region ( MPADecodeContext *  s,
GranuleDef *  g 
) [static]

Definition at line 177 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

static void ff_region_offset2size ( GranuleDef *  g  )  [static]

Convert region offsets to region sizes and truncate size to big_values.

Definition at line 166 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

static void flush ( AVCodecContext *  avctx  )  [static]

Definition at line 1715 of file mpegaudiodec.c.

static int get_bitsz ( GetBitContext *  s,
int  n 
) [inline, static]

Definition at line 822 of file mpegaudiodec.c.

Referenced by huffman_decode().

static int huffman_decode ( MPADecodeContext *  s,
GranuleDef *  g,
int16_t *  exponents,
int  end_pos2 
) [static]

Definition at line 858 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

static void imdct12 ( INTFLOAT *  out,
INTFLOAT *  in 
) [static]

Definition at line 461 of file mpegaudiodec.c.

Referenced by compute_imdct().

static int l1_unscale ( int  n,
int  mant,
int  scale_factor 
) [inline, static]

Definition at line 229 of file mpegaudiodec.c.

Referenced by mp_decode_layer1(), and mp_decode_layer2().

static int l2_unscale_group ( int  steps,
int  mant,
int  scale_factor 
) [inline, static]

Definition at line 243 of file mpegaudiodec.c.

Referenced by mp_decode_layer2().

static int l3_unscale ( int  value,
int  exponent 
) [inline, static]

Definition at line 259 of file mpegaudiodec.c.

Referenced by huffman_decode().

static av_always_inline void lsf_sf_expand ( int *  slen,
int  sf,
int  n1,
int  n2,
int  n3 
) [static]

Definition at line 775 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

static int mp_decode_frame ( MPADecodeContext *  s,
OUT_INT *  samples,
const uint8_t *  buf,
int  buf_size 
) [static]

Definition at line 1569 of file mpegaudiodec.c.

static int mp_decode_layer1 ( MPADecodeContext *  s  )  [static]

Definition at line 503 of file mpegaudiodec.c.

Referenced by mp_decode_frame().

static int mp_decode_layer2 ( MPADecodeContext *  s  )  [static]

Definition at line 568 of file mpegaudiodec.c.

Referenced by mp_decode_frame().

static int mp_decode_layer3 ( MPADecodeContext *  s  )  [static]

Definition at line 1316 of file mpegaudiodec.c.

Referenced by mp_decode_frame().

static void reorder_block ( MPADecodeContext *  s,
GranuleDef *  g 
) [static]

Definition at line 1014 of file mpegaudiodec.c.

Referenced by mp_decode_layer3().

static void switch_buffer ( MPADecodeContext *  s,
int *  pos,
int *  end_pos,
int *  end_pos2 
) [static]

Definition at line 828 of file mpegaudiodec.c.

Referenced by huffman_decode().

Variable Documentation

uint16_t band_index_long[9][23] [static]

Definition at line 132 of file mpegaudiodec.c.

Referenced by decode_init_static(), and ff_init_long_region().

INTFLOAT csa_table[8][4] [static]

Definition at line 137 of file mpegaudiodec.c.

Referenced by compute_antialias_mips_fixed(), compute_antialias_mips_float(), and decode_init_static().

int16_t division_tab3[1<< 6] [static]

Definition at line 139 of file mpegaudiodec.c.

int16_t division_tab5[1<< 8] [static]

Definition at line 140 of file mpegaudiodec.c.

int16_t division_tab9[1<< 11] [static]

Definition at line 141 of file mpegaudiodec.c.

int16_t* const division_tabs[4] [static]

Initial value:

 {
    division_tab3, division_tab5, NULL, division_tab9
}

Definition at line 143 of file mpegaudiodec.c.

Referenced by decode_init_static(), and mp_decode_layer2().

VLC huff_quad_vlc[2] [static]

Definition at line 128 of file mpegaudiodec.c.

VLC_TYPE huff_quad_vlc_tables[128+16][2] [static]

Definition at line 129 of file mpegaudiodec.c.

Referenced by decode_init_static().

const int huff_quad_vlc_tables_sizes[2] = { 128, 16 } [static]

Definition at line 130 of file mpegaudiodec.c.

Referenced by decode_init_static().

VLC huff_vlc[16] [static]

Definition at line 119 of file mpegaudiodec.c.

VLC_TYPE huff_vlc_tables[0+128+128+128+130+128+154+166+142+204+190+170+542+460+662+414][2] [static]

Definition at line 123 of file mpegaudiodec.c.

Referenced by decode_init_static().

const int huff_vlc_tables_sizes[16] [static]

Initial value:

 {
    0,  128,  128,  128,  130,  128,  154,  166,
  142,  204,  190,  170,  542,  460,  662,  414
}

Definition at line 124 of file mpegaudiodec.c.

Referenced by decode_init_static().

INTFLOAT is_table[2][16] [static]

Definition at line 135 of file mpegaudiodec.c.

Referenced by compute_stereo(), and decode_init_static().

INTFLOAT is_table_lsf[2][2][16] [static]

Definition at line 136 of file mpegaudiodec.c.

Referenced by compute_stereo(), and decode_init_static().

uint16_t scale_factor_modshift[64] [static]

Definition at line 148 of file mpegaudiodec.c.

Referenced by decode_init_static(), l1_unscale(), and l2_unscale_group().

int32_t scale_factor_mult[15][3] [static]

Definition at line 150 of file mpegaudiodec.c.

Referenced by decode_init_static(), encode_frame(), l1_unscale(), and MPA_encode_init().

const int32_t scale_factor_mult2[3][3] [static]

Initial value:

 {
    SCALE_GEN(4.0 / 3.0), 
    SCALE_GEN(4.0 / 5.0), 
    SCALE_GEN(4.0 / 9.0), 
}

Definition at line 156 of file mpegaudiodec.c.

Referenced by l2_unscale_group().

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