-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);
+#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);