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/**
* @file mpegaudio.h
* mpeg audio declarations for both encoder and decoder.
*/
/* 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))
int l2_select_table(int bitrate, int nb_channels, int freq, int lsf);
int mpa_decode_header(AVCodecContext *avctx, uint32_t head);
extern const uint16_t mpa_bitrate_tab[2][3][15];
extern const uint16_t mpa_freq_tab[3];
extern const unsigned char *alloc_tables[5];
extern const double enwindow[512];
extern const int sblimit_table[5];
extern const int quant_steps[17];
extern const int quant_bits[17];
extern const int32_t mpa_enwindow[257];
/* 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;
}
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