2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of Libav.
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * mpeg audio declarations for both encoder and decoder.
26 #ifndef AVCODEC_MPEGAUDIO_H
27 #define AVCODEC_MPEGAUDIO_H
30 # define CONFIG_FLOAT 0
38 /* max frame size, in samples */
39 #define MPA_FRAME_SIZE 1152
41 /* max compressed frame size */
42 #define MPA_MAX_CODED_FRAME_SIZE 1792
44 #define MPA_MAX_CHANNELS 2
46 #define SBLIMIT 32 /* number of subbands */
53 /* header + layer + bitrate + freq + lsf/mpeg25 */
54 #define SAME_HEADER_MASK \
55 (0xffe00000 | (3 << 17) | (0xf << 12) | (3 << 10) | (3 << 19))
57 #define MP3_MASK 0xFFFE0CCF
59 #if CONFIG_MPEGAUDIO_HP
60 #define FRAC_BITS 23 /* fractional bits for sb_samples and dct */
61 #define WFRAC_BITS 16 /* fractional bits for window */
63 #define FRAC_BITS 15 /* fractional bits for sb_samples and dct */
64 #define WFRAC_BITS 14 /* fractional bits for window */
67 #define FRAC_ONE (1 << FRAC_BITS)
69 #define FIX(a) ((int)((a) * FRAC_ONE))
72 typedef float OUT_INT;
73 #define OUT_FMT AV_SAMPLE_FMT_FLT
75 typedef int16_t OUT_INT;
76 #define OUT_MAX INT16_MAX
77 #define OUT_MIN INT16_MIN
78 #define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)
79 #define OUT_FMT AV_SAMPLE_FMT_S16
83 # define INTFLOAT float
84 typedef float MPA_INT;
87 typedef int16_t MPA_INT;
90 typedef int32_t MPA_INT;
93 #define BACKSTEP_SIZE 512
96 /* layer 3 "granule" */
97 typedef struct GranuleDef {
102 int scalefac_compress;
104 uint8_t switch_point;
106 int subblock_gain[3];
107 uint8_t scalefac_scale;
108 uint8_t count1table_select;
109 int region_size[3]; /* number of huffman codes in each region */
111 int short_start, long_end; /* long/short band indexes */
112 uint8_t scale_factors[40];
113 INTFLOAT sb_hybrid[SBLIMIT * 18]; /* 576 samples */
116 #define MPA_DECODE_HEADER \
118 int error_protection; \
121 int sample_rate_index; /* between 0 and 8 */ \
128 typedef struct MPADecodeHeader {
132 typedef struct MPADecodeContext {
134 uint8_t last_buf[2*BACKSTEP_SIZE + EXTRABYTES];
136 /* next header (used in free format parsing) */
137 uint32_t free_format_next_header;
140 DECLARE_ALIGNED(16, MPA_INT, synth_buf)[MPA_MAX_CHANNELS][512 * 2];
141 int synth_buf_offset[MPA_MAX_CHANNELS];
142 DECLARE_ALIGNED(16, INTFLOAT, sb_samples)[MPA_MAX_CHANNELS][36][SBLIMIT];
143 INTFLOAT mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
144 GranuleDef granules[2][2]; /* Used in Layer 3 */
148 int adu_mode; ///< 0 for standard mp3, 1 for adu formatted mp3
150 int error_recognition;
151 AVCodecContext* avctx;
155 void (*apply_window_mp3)(MPA_INT *synth_buf, MPA_INT *window,
156 int *dither_state, OUT_INT *samples, int incr);
159 /* layer 3 huffman tables */
160 typedef struct HuffTable {
163 const uint16_t *codes;
166 int ff_mpa_l2_select_table(int bitrate, int nb_channels, int freq, int lsf);
167 int ff_mpa_decode_header(AVCodecContext *avctx, uint32_t head, int *sample_rate, int *channels, int *frame_size, int *bitrate);
168 extern MPA_INT ff_mpa_synth_window[];
169 void ff_mpa_synth_init(MPA_INT *window);
170 void ff_mpa_synth_filter(MPA_INT *synth_buf_ptr, int *synth_buf_offset,
171 MPA_INT *window, int *dither_state,
172 OUT_INT *samples, int incr,
173 INTFLOAT sb_samples[SBLIMIT]);
175 void ff_mpa_synth_init_float(MPA_INT *window);
176 void ff_mpa_synth_filter_float(MPADecodeContext *s,
177 MPA_INT *synth_buf_ptr, int *synth_buf_offset,
178 MPA_INT *window, int *dither_state,
179 OUT_INT *samples, int incr,
180 INTFLOAT sb_samples[SBLIMIT]);
182 void ff_mpegaudiodec_init_mmx(MPADecodeContext *s);
183 void ff_mpegaudiodec_init_altivec(MPADecodeContext *s);
185 /* fast header check for resync */
186 static inline int ff_mpa_check_header(uint32_t header){
188 if ((header & 0xffe00000) != 0xffe00000)
191 if ((header & (3<<17)) == 0)
194 if ((header & (0xf<<12)) == 0xf<<12)
197 if ((header & (3<<10)) == 3<<10)
202 #endif /* AVCODEC_MPEGAUDIO_H */