3 * mpeg audio declarations for both encoder and decoder.
6 /* max frame size, in samples */
7 #define MPA_FRAME_SIZE 1152
9 /* max compressed frame size */
10 #define MPA_MAX_CODED_FRAME_SIZE 1792
12 #define MPA_MAX_CHANNELS 2
14 #define SBLIMIT 32 /* number of subbands */
21 /* header + layer + bitrate + freq + lsf/mpeg25 */
22 #define SAME_HEADER_MASK \
23 (0xffe00000 | (3 << 17) | (0xf << 12) | (3 << 10) | (3 << 19))
25 /* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
28 #ifdef USE_HIGHPRECISION
29 #define FRAC_BITS 23 /* fractional bits for sb_samples and dct */
30 #define WFRAC_BITS 16 /* fractional bits for window */
32 #define FRAC_BITS 15 /* fractional bits for sb_samples and dct */
33 #define WFRAC_BITS 14 /* fractional bits for window */
36 #if defined(USE_HIGHPRECISION) && defined(CONFIG_AUDIO_NONSHORT)
37 typedef int32_t OUT_INT;
38 #define OUT_MAX INT32_MAX
39 #define OUT_MIN INT32_MIN
40 #define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 31)
42 typedef int16_t OUT_INT;
43 #define OUT_MAX INT16_MAX
44 #define OUT_MIN INT16_MIN
45 #define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)
49 typedef int16_t MPA_INT;
51 typedef int32_t MPA_INT;
54 int l2_select_table(int bitrate, int nb_channels, int freq, int lsf);
55 int mpa_decode_header(AVCodecContext *avctx, uint32_t head);
56 void ff_mpa_synth_init(MPA_INT *window);
57 void ff_mpa_synth_filter(MPA_INT *synth_buf_ptr, int *synth_buf_offset,
58 MPA_INT *window, int *dither_state,
59 OUT_INT *samples, int incr,
60 int32_t sb_samples[SBLIMIT]);
62 extern const uint16_t mpa_bitrate_tab[2][3][15];
63 extern const uint16_t mpa_freq_tab[3];
64 extern const unsigned char *alloc_tables[5];
65 extern const double enwindow[512];
66 extern const int sblimit_table[5];
67 extern const int quant_steps[17];
68 extern const int quant_bits[17];
69 extern const int32_t mpa_enwindow[257];
71 /* fast header check for resync */
72 static inline int ff_mpa_check_header(uint32_t header){
74 if ((header & 0xffe00000) != 0xffe00000)
77 if ((header & (3<<17)) == 0)
80 if ((header & (0xf<<12)) == 0xf<<12)
83 if ((header & (3<<10)) == 3<<10)