libavcodec/mpc.h

   1 /*
   2  * Musepack decoder
   3  * Copyright (c) 2006 Konstantin Shishkov
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * Libav is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * Musepack decoder
  25  * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
  26  * divided into 32 subbands.
  27  */
  28
  29 #ifndef AVCODEC_MPC_H
  30 #define AVCODEC_MPC_H
  31
  32 #include "libavutil/lfg.h"
  33
  34 #include "avcodec.h"
  35 #include "bswapdsp.h"
  36 #include "mpegaudio.h"
  37 #include "mpegaudiodsp.h"
  38
  39 #define BANDS            32
  40 #define SAMPLES_PER_BAND 36
  41 #define MPC_FRAME_SIZE   (BANDS * SAMPLES_PER_BAND)
  42
  43 /** Subband structure - hold all variables for each subband */
  44 typedef struct Band {
  45     int msf; ///< mid-stereo flag
  46     int res[2];
  47     int scfi[2];
  48     int scf_idx[2][3];
  49     int Q[2];
  50 }Band;
  51
  52 typedef struct MPCContext {
  53     BswapDSPContext bdsp;
  54     MPADSPContext mpadsp;
  55     int IS, MSS, gapless;
  56     int lastframelen;
  57     int maxbands, last_max_band;
  58     int last_bits_used;
  59     int oldDSCF[2][BANDS];
  60     Band bands[BANDS];
  61     int Q[2][MPC_FRAME_SIZE];
  62     int cur_frame, frames;
  63     uint8_t *bits;
  64     int buf_size;
  65     AVLFG rnd;
  66     int frames_to_skip;
  67     /* for synthesis */
  68     DECLARE_ALIGNED(16, MPA_INT, synth_buf)[MPA_MAX_CHANNELS][512*2];
  69     int synth_buf_offset[MPA_MAX_CHANNELS];
  70     DECLARE_ALIGNED(16, int32_t, sb_samples)[MPA_MAX_CHANNELS][36][SBLIMIT];
  71 } MPCContext;
  72
  73 void ff_mpc_init(void);
  74 void ff_mpc_dequantize_and_synth(MPCContext *c, int maxband, int16_t **out, int channels);
  75
  76 #endif /* AVCODEC_MPC_H */