ffmpeg/libavcodec/mpegaudio.h

   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
  35 /* max frame size, in samples */
  36 #define MPA_FRAME_SIZE 1152
  37
  38 /* max compressed frame size */
  39 #define MPA_MAX_CODED_FRAME_SIZE 1792
  40
  41 #define MPA_MAX_CHANNELS 2
  42
  43 #define SBLIMIT 32 /* number of subbands */
  44
  45 #define MPA_STEREO  0
  46 #define MPA_JSTEREO 1
  47 #define MPA_DUAL    2
  48 #define MPA_MONO    3
  49
  50 #ifndef FRAC_BITS
  51 #define FRAC_BITS   23   /* fractional bits for sb_samples and dct */
  52 #define WFRAC_BITS  16   /* fractional bits for window */
  53 #endif
  54
  55 #define IMDCT_SCALAR 1.759
  56
  57 #define FRAC_ONE    (1 << FRAC_BITS)
  58
  59 #define FIX(a)   ((int)((a) * FRAC_ONE))
  60
  61 #if USE_FLOATS
  62 #   define INTFLOAT float
  63 typedef float MPA_INT;
  64 typedef float OUT_INT;
  65 #elif FRAC_BITS <= 15
  66 #   define INTFLOAT int
  67 typedef int16_t MPA_INT;
  68 typedef int16_t OUT_INT;
  69 #else
  70 #   define INTFLOAT int
  71 typedef int32_t MPA_INT;
  72 typedef int16_t OUT_INT;
  73 #endif
  74
  75 int ff_mpa_l2_select_table(int bitrate, int nb_channels, int freq, int lsf);
  76
  77 #endif /* AVCODEC_MPEGAUDIO_H */