-#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;
-
-int l2_select_table(int bitrate, int nb_channels, int freq, int lsf);
-int 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;
-}