mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
111 lines
2.8 KiB
111 lines
2.8 KiB
/* |
|
* 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 |
|
* mpeg audio declarations for both encoder and decoder. |
|
*/ |
|
|
|
#ifndef AVCODEC_MPEGAUDIO_H |
|
#define AVCODEC_MPEGAUDIO_H |
|
|
|
#ifndef CONFIG_FLOAT |
|
# define CONFIG_FLOAT 0 |
|
#endif |
|
|
|
#include "avcodec.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 |
|
|
|
#define MP3_MASK 0xFFFE0CCF |
|
|
|
#ifndef FRAC_BITS |
|
#define FRAC_BITS 23 /* fractional bits for sb_samples and dct */ |
|
#define WFRAC_BITS 16 /* fractional bits for window */ |
|
#endif |
|
|
|
#define FRAC_ONE (1 << FRAC_BITS) |
|
|
|
#define FIX(a) ((int)((a) * FRAC_ONE)) |
|
|
|
#if CONFIG_FLOAT |
|
# define INTFLOAT float |
|
typedef float MPA_INT; |
|
typedef float OUT_INT; |
|
#elif FRAC_BITS <= 15 |
|
# define INTFLOAT int |
|
typedef int16_t MPA_INT; |
|
typedef int16_t OUT_INT; |
|
#else |
|
# define INTFLOAT int |
|
typedef int32_t MPA_INT; |
|
typedef int16_t OUT_INT; |
|
#endif |
|
|
|
#define MPA_DECODE_HEADER \ |
|
int frame_size; \ |
|
int error_protection; \ |
|
int layer; \ |
|
int sample_rate; \ |
|
int sample_rate_index; /* between 0 and 8 */ \ |
|
int bit_rate; \ |
|
int nb_channels; \ |
|
int mode; \ |
|
int mode_ext; \ |
|
int lsf; |
|
|
|
typedef struct MPADecodeHeader { |
|
MPA_DECODE_HEADER |
|
} MPADecodeHeader; |
|
|
|
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, int *channels, int *frame_size, int *bitrate); |
|
|
|
/* 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 /* AVCODEC_MPEGAUDIO_H */
|
|
|