mirror of
https://git.videolan.org/git/ffmpeg.git
synced 2024-09-06 08:08:58 +02:00
156 lines
4.4 KiB
C
156 lines
4.4 KiB
C
/*
|
|
* copyright (c) 2001 Fabrice Bellard
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg 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 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg 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 FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file mpegaudio.h
|
|
* mpeg audio declarations for both encoder and decoder.
|
|
*/
|
|
|
|
#ifndef MPEGAUDIO_H
|
|
#define MPEGAUDIO_H
|
|
|
|
#include "avcodec.h"
|
|
#include "bitstream.h"
|
|
#include "dsputil.h"
|
|
|
|
/* max frame size, in samples */
|
|
#define MPA_FRAME_SIZE 1152
|
|
|
|
/* max compressed frame size */
|
|
#define MPA_MAX_CODED_FRAME_SIZE 1792
|
|
|
|
#define MPA_MAX_CHANNELS 2
|
|
|
|
#define SBLIMIT 32 /* number of subbands */
|
|
|
|
#define MPA_STEREO 0
|
|
#define MPA_JSTEREO 1
|
|
#define MPA_DUAL 2
|
|
#define MPA_MONO 3
|
|
|
|
/* header + layer + bitrate + freq + lsf/mpeg25 */
|
|
#define SAME_HEADER_MASK \
|
|
(0xffe00000 | (3 << 17) | (0xf << 12) | (3 << 10) | (3 << 19))
|
|
|
|
#define MP3_MASK 0xFFFE0CCF
|
|
|
|
/* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
|
|
audio decoder */
|
|
|
|
#ifdef USE_HIGHPRECISION
|
|
#define FRAC_BITS 23 /* fractional bits for sb_samples and dct */
|
|
#define WFRAC_BITS 16 /* fractional bits for window */
|
|
#else
|
|
#define FRAC_BITS 15 /* fractional bits for sb_samples and dct */
|
|
#define WFRAC_BITS 14 /* fractional bits for window */
|
|
#endif
|
|
|
|
#define FRAC_ONE (1 << FRAC_BITS)
|
|
|
|
#define FIX(a) ((int)((a) * FRAC_ONE))
|
|
|
|
#if defined(USE_HIGHPRECISION) && defined(CONFIG_AUDIO_NONSHORT)
|
|
typedef int32_t OUT_INT;
|
|
#define OUT_MAX INT32_MAX
|
|
#define OUT_MIN INT32_MIN
|
|
#define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 31)
|
|
#else
|
|
typedef int16_t OUT_INT;
|
|
#define OUT_MAX INT16_MAX
|
|
#define OUT_MIN INT16_MIN
|
|
#define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)
|
|
#endif
|
|
|
|
#if FRAC_BITS <= 15
|
|
typedef int16_t MPA_INT;
|
|
#else
|
|
typedef int32_t MPA_INT;
|
|
#endif
|
|
|
|
#define BACKSTEP_SIZE 512
|
|
#define EXTRABYTES 24
|
|
|
|
struct GranuleDef;
|
|
|
|
typedef struct MPADecodeContext {
|
|
DECLARE_ALIGNED_8(uint8_t, last_buf[2*BACKSTEP_SIZE + EXTRABYTES]);
|
|
int last_buf_size;
|
|
int frame_size;
|
|
/* 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;
|
|
GetBitContext gb;
|
|
GetBitContext in_gb;
|
|
int nb_channels;
|
|
int mode;
|
|
int mode_ext;
|
|
int lsf;
|
|
DECLARE_ALIGNED_16(MPA_INT, synth_buf[MPA_MAX_CHANNELS][512 * 2]);
|
|
int synth_buf_offset[MPA_MAX_CHANNELS];
|
|
DECLARE_ALIGNED_16(int32_t, sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT]);
|
|
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
|
|
int dither_state;
|
|
int error_resilience;
|
|
AVCodecContext* avctx;
|
|
} MPADecodeContext;
|
|
|
|
/* layer 3 huffman tables */
|
|
typedef struct HuffTable {
|
|
int xsize;
|
|
const uint8_t *bits;
|
|
const uint16_t *codes;
|
|
} HuffTable;
|
|
|
|
int ff_mpa_l2_select_table(int bitrate, int nb_channels, int freq, int lsf);
|
|
int ff_mpa_decode_header(AVCodecContext *avctx, uint32_t head, int *sample_rate);
|
|
void ff_mpa_synth_init(MPA_INT *window);
|
|
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]);
|
|
|
|
/* fast header check for resync */
|
|
static inline int ff_mpa_check_header(uint32_t header){
|
|
/* header */
|
|
if ((header & 0xffe00000) != 0xffe00000)
|
|
return -1;
|
|
/* layer check */
|
|
if ((header & (3<<17)) == 0)
|
|
return -1;
|
|
/* bit rate */
|
|
if ((header & (0xf<<12)) == 0xf<<12)
|
|
return -1;
|
|
/* frequency */
|
|
if ((header & (3<<10)) == 3<<10)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
#endif /* MPEGAUDIO_H */
|