mpegaudio.h (2064B)
1 /* 2 * copyright (c) 2001 Fabrice Bellard 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg 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. 10 * 11 * FFmpeg 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. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21 /** 22 * @file 23 * mpeg audio declarations for both encoder and decoder. 24 */ 25 26 #ifndef AVCODEC_MPEGAUDIO_H 27 #define AVCODEC_MPEGAUDIO_H 28 29 #ifndef USE_FLOATS 30 # define USE_FLOATS 0 31 #endif 32 33 #include <stdint.h> 34 #include "libavutil/internal.h" 35 36 /* max frame size, in samples */ 37 #define MPA_FRAME_SIZE 1152 38 39 /* max compressed frame size */ 40 #define MPA_MAX_CODED_FRAME_SIZE 1792 41 42 #define MPA_MAX_CHANNELS 2 43 44 #define SBLIMIT 32 /* number of subbands */ 45 46 #define MPA_STEREO 0 47 #define MPA_JSTEREO 1 48 #define MPA_DUAL 2 49 #define MPA_MONO 3 50 51 #ifndef FRAC_BITS 52 #define FRAC_BITS 23 /* fractional bits for sb_samples and dct */ 53 #define WFRAC_BITS 16 /* fractional bits for window */ 54 #endif 55 56 #define IMDCT_SCALAR 1.759 57 58 #define FRAC_ONE (1 << FRAC_BITS) 59 60 #define FIX(a) ((int)((a) * FRAC_ONE)) 61 62 #if USE_FLOATS 63 # define INTFLOAT float 64 # define SUINTFLOAT float 65 typedef float MPA_INT; 66 typedef float OUT_INT; 67 #elif FRAC_BITS <= 15 68 # define INTFLOAT int 69 # define SUINTFLOAT SUINT 70 typedef int16_t MPA_INT; 71 typedef int16_t OUT_INT; 72 #else 73 # define INTFLOAT int 74 # define SUINTFLOAT SUINT 75 typedef int32_t MPA_INT; 76 typedef int16_t OUT_INT; 77 #endif 78 79 int ff_mpa_l2_select_table(int bitrate, int nb_channels, int freq, int lsf); 80 81 #endif /* AVCODEC_MPEGAUDIO_H */