MPEG Audio decoder. More...

#include "libavutil/attributes.h"
#include "libavutil/avassert.h"
#include "libavutil/channel_layout.h"
#include "libavutil/float_dsp.h"
#include "libavutil/libm.h"
#include "avcodec.h"
#include "get_bits.h"
#include "internal.h"
#include "mathops.h"
#include "mpegaudiodsp.h"
#include "mpegaudio.h"
#include "mpegaudiodecheader.h"
#include "mpegaudiodata.h"
#include "mpegaudiodectab.h"
#include "mpegaudio_tablegen.h"

Data Structures
struct	GranuleDef

struct	MPADecodeContext

Macros
#define	BACKSTEP_SIZE 512

#define	EXTRABYTES 24

#define	LAST_BUF_SIZE 2 * BACKSTEP_SIZE + EXTRABYTES

#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	region_offset2size (GranuleDef *g)
	Convert region offsets to region sizes and truncate size to big_values.

static void	init_short_region (MPADecodeContext s, GranuleDef g)

static void	init_long_region (MPADecodeContext s, GranuleDef g, int ra1, int ra2)

static void	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	mp_flush (MPADecodeContext *ctx)

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_template.c.

Macro Definition Documentation

#define BACKSTEP_SIZE 512

Definition at line 46 of file mpegaudiodec_template.c.

Referenced by mp_decode_frame().

#define EXTRABYTES 24

Definition at line 47 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

#define LAST_BUF_SIZE 2 * BACKSTEP_SIZE + EXTRABYTES

Definition at line 48 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

#define HEADER_SIZE 4

Definition at line 92 of file mpegaudiodec_template.c.

Referenced by decode_frame(), and mp_decode_frame().

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

Definition at line 132 of file mpegaudiodec_template.c.

#define C3 FIXHR(0.86602540378443864676/2)

Definition at line 437 of file mpegaudiodec_template.c.

Referenced by imdct12().

#define C4 FIXHR(0.70710678118654752439/2)

Definition at line 438 of file mpegaudiodec_template.c.

Referenced by imdct12().

#define C5 FIXHR(0.51763809020504152469/2)

Definition at line 439 of file mpegaudiodec_template.c.

Referenced by imdct12().

#define C6 FIXHR(1.93185165257813657349/4)

Definition at line 440 of file mpegaudiodec_template.c.

Referenced by imdct12().

#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 738 of file mpegaudiodec_template.c.

Referenced by avfilter_register_all(), and lsf_sf_expand().

#define READ_FLIP_SIGN	(	dst,
		src
	)

Value:

v = -get_bits1(&s->gb); \

*(dst) = (*(src) ^ v) - v;

Definition at line 836 of file mpegaudiodec_template.c.

Referenced by huffman_decode().

#define ISQRT2 FIXR(0.70710678118654752440)

Definition at line 1025 of file mpegaudiodec_template.c.

Referenced by compute_stereo().

#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 1174 of file mpegaudiodec_template.c.

Referenced by compute_antialias().

Function Documentation

static void region_offset2size ( GranuleDef * g )

static

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

Definition at line 145 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

static void init_short_region	(	MPADecodeContext *	s,
		GranuleDef *	g
	)

static

Definition at line 156 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

static void init_long_region	(	MPADecodeContext *	s,
		GranuleDef *	g,
		int	ra1,
		int	ra2
	)

static

Definition at line 174 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

static void compute_band_indexes	(	MPADecodeContext *	s,
		GranuleDef *	g
	)

static

Definition at line 184 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

static int l1_unscale	(	int	n,
		int	mant,
		int	scale_factor
	)

inlinestatic

Definition at line 211 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer1(), and mp_decode_layer2().

static int l2_unscale_group	(	int	steps,
		int	mant,
		int	scale_factor
	)

inlinestatic

Definition at line 225 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer2().

static int l3_unscale	(	int	value,
		int	exponent
	)

inlinestatic

Definition at line 241 of file mpegaudiodec_template.c.

Referenced by huffman_decode().

static av_cold void decode_init_static ( void )

static

Definition at line 260 of file mpegaudiodec_template.c.

Referenced by decode_init().

static av_cold int decode_init ( AVCodecContext * avctx )

static

Definition at line 409 of file mpegaudiodec_template.c.

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

static

Definition at line 444 of file mpegaudiodec_template.c.

Referenced by compute_imdct().

static int mp_decode_layer1 ( MPADecodeContext * s )

static

Definition at line 486 of file mpegaudiodec_template.c.

Referenced by mp_decode_frame().

static int mp_decode_layer2 ( MPADecodeContext * s )

static

Definition at line 551 of file mpegaudiodec_template.c.

Referenced by mp_decode_frame().

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

static

Definition at line 758 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

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

static

Definition at line 767 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

static int get_bitsz	(	GetBitContext *	s,
		int	n
	)

inlinestatic

Definition at line 805 of file mpegaudiodec_template.c.

Referenced by huffman_decode().

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

static

Definition at line 811 of file mpegaudiodec_template.c.

Referenced by huffman_decode().

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

static

Definition at line 841 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

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

static

Definition at line 992 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

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

static

Definition at line 1027 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

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

static

Definition at line 1183 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

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

static

Definition at line 1214 of file mpegaudiodec_template.c.

Referenced by mp_decode_layer3().

static int mp_decode_layer3 ( MPADecodeContext * s )

static

Definition at line 1294 of file mpegaudiodec_template.c.

Referenced by mp_decode_frame().

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

static

Definition at line 1548 of file mpegaudiodec_template.c.

Referenced by decode_frame().

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

static

Definition at line 1636 of file mpegaudiodec_template.c.

static void mp_flush ( MPADecodeContext * ctx )

static

Definition at line 1705 of file mpegaudiodec_template.c.

Referenced by flush().

static void flush ( AVCodecContext * avctx )

static

Definition at line 1713 of file mpegaudiodec_template.c.

Variable Documentation

VLC huff_vlc[16]

static

Definition at line 98 of file mpegaudiodec_template.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 102 of file mpegaudiodec_template.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 103 of file mpegaudiodec_template.c.

Referenced by decode_init_static().

VLC huff_quad_vlc[2]

static

Definition at line 107 of file mpegaudiodec_template.c.

VLC_TYPE huff_quad_vlc_tables[128+16][2]

static

Definition at line 108 of file mpegaudiodec_template.c.

Referenced by decode_init_static().

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

static

Definition at line 109 of file mpegaudiodec_template.c.

Referenced by decode_init_static().

uint16_t band_index_long[9][23]

static

Definition at line 111 of file mpegaudiodec_template.c.

Referenced by decode_init_static(), and init_long_region().

INTFLOAT is_table[2][16]

static

Definition at line 114 of file mpegaudiodec_template.c.

Referenced by compute_stereo(), and decode_init_static().

INTFLOAT is_table_lsf[2][2][16]

static

Definition at line 115 of file mpegaudiodec_template.c.

Referenced by compute_stereo(), and decode_init_static().

INTFLOAT csa_table[8][4]

static

Definition at line 116 of file mpegaudiodec_template.c.

Referenced by decode_init_static().

int16_t division_tab3[1<< 6]

static

Definition at line 118 of file mpegaudiodec_template.c.

int16_t division_tab5[1<< 8]

static

Definition at line 119 of file mpegaudiodec_template.c.

int16_t division_tab9[1<< 11]

static

Definition at line 120 of file mpegaudiodec_template.c.

int16_t* const division_tabs[4]

static

Initial value:

= {
    division_tab3, division_tab5, NULL, division_tab9
}

Definition at line 122 of file mpegaudiodec_template.c.

Referenced by decode_init_static(), and mp_decode_layer2().

uint16_t scale_factor_modshift[64]

static

Definition at line 127 of file mpegaudiodec_template.c.

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

int32_t scale_factor_mult[15][3]

static

Definition at line 129 of file mpegaudiodec_template.c.

Referenced by decode_init_static(), and l1_unscale().

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 135 of file mpegaudiodec_template.c.

Referenced by l2_unscale_group().

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation