apps/codecs/libmusepack/decoder.h

   1 /*
   2   Copyright (c) 2005, The Musepack Development Team
   3   All rights reserved.
   4
   5   Redistribution and use in source and binary forms, with or without
   6   modification, are permitted provided that the following conditions are
   7   met:
   8
   9   * Redistributions of source code must retain the above copyright
  10   notice, this list of conditions and the following disclaimer.
  11
  12   * Redistributions in binary form must reproduce the above
  13   copyright notice, this list of conditions and the following
  14   disclaimer in the documentation and/or other materials provided
  15   with the distribution.
  16
  17   * Neither the name of the The Musepack Development Team nor the
  18   names of its contributors may be used to endorse or promote
  19   products derived from this software without specific prior
  20   written permission.
  21
  22   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  25   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  26   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  27   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  28   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  32   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33 */
  34
  35 /// \file decoder.h
  36
  37 #ifndef _mpcdec_decoder_h_
  38 #define _mpcdec_decoder_h_
  39
  40 #include "huffman.h"
  41 #include "math.h"
  42 #include "musepack.h"
  43 #include "reader.h"
  44 #include "streaminfo.h"
  45
  46 // define this to enable/disable support for streamversion SV4-6
  47 //#define MPC_SUPPORT_SV456
  48
  49 // SCF_HACK is used to avoid possible distortion after seeking with mpc files
  50 // background: scf's are coded differential in time domain. if you seek to the
  51 // desired postion it might happen that the baseline is missed and the resulting
  52 // scf is much too high (hissing noise). this hack uses the lowest scaling until
  53 // a non-differential scf could be decoded after seek. through this hack subbands
  54 // are faded out until there was at least a single non-differential scf found.
  55 #define SCF_HACK
  56
  57 enum {
  58     MPC_V_MEM = 2304,
  59     MPC_DECODER_MEMSIZE = 16384,  // overall buffer size (words)
  60     MPC_SEEK_BUFFER_SIZE = 8192, // seek buffer size (words)
  61 };
  62
  63 typedef struct {
  64     mpc_int16_t  L [36];
  65     mpc_int16_t  R [36];
  66 } QuantTyp;
  67
  68 typedef struct mpc_decoder_t {
  69     mpc_reader *r;
  70
  71     /// @name internal state variables
  72     //@{
  73
  74     mpc_uint32_t  next;
  75     mpc_uint32_t  dword; /// currently decoded 32bit-word
  76     mpc_uint32_t  pos;   /// bit-position within dword
  77     mpc_uint32_t  *Speicher; /// read-buffer
  78     mpc_uint32_t  Zaehler; /// actual index within read-buffer
  79     mpc_uint32_t  Ring;
  80
  81     mpc_uint32_t  samples_to_skip;
  82     mpc_uint32_t  last_block_samples;
  83     mpc_uint32_t  FwdJumpInfo;
  84     mpc_uint32_t  ActDecodePos;
  85
  86
  87     mpc_uint32_t  DecodedFrames;
  88     mpc_uint32_t  OverallFrames;
  89     mpc_int32_t   SampleRate;                 // Sample frequency
  90
  91     mpc_uint32_t  StreamVersion;              // version of bitstream
  92     mpc_int32_t   Max_Band;
  93     mpc_uint32_t  MPCHeaderPos;               // AB: needed to support ID3v2
  94
  95     mpc_uint32_t  FrameWasValid;
  96     mpc_uint32_t  MS_used;                    // MS-coding used ?
  97     mpc_uint32_t  TrueGaplessPresent;
  98
  99     mpc_uint32_t  WordsRead;                  // counts amount of decoded dwords
 100
 101     // randomizer state variables
 102     mpc_uint32_t  __r1;
 103     mpc_uint32_t  __r2;
 104
 105     mpc_int8_t    SCF_Index_L [32] [3];
 106     mpc_int8_t    SCF_Index_R [32] [3];       // holds scalefactor-indices
 107     QuantTyp      Q [32];                     // holds quantized samples
 108     mpc_int8_t    Res_L [32];
 109     mpc_int8_t    Res_R [32];                 // holds the chosen quantizer for each subband
 110 #ifdef MPC_SUPPORT_SV456
 111     mpc_bool_t    DSCF_Flag_L [32];
 112     mpc_bool_t    DSCF_Flag_R [32];           // differential SCF used?
 113 #endif
 114     mpc_int8_t    SCFI_L [32];
 115     mpc_int8_t    SCFI_R [32];                // describes order of transmitted SCF
 116     mpc_bool_t    MS_Flag[32];                // MS used?
 117
 118     mpc_uint32_t  SeekTableCounter;           // used to sum up skip info, if SeekTable_Step != 1
 119     mpc_uint32_t  MaxDecodedFrames;           // Maximum frames decoded (indicates usable seek table entries)
 120     mpc_uint32_t* SeekTable;                  // seek table itself
 121     mpc_uint8_t   SeekTable_Step;             // 1<<SeekTable_Step = frames per table index
 122     mpc_uint32_t  SeekTable_Mask;             // used to avoid modulo-operation in seek
 123
 124 #ifdef MPC_FIXED_POINT
 125     mpc_uint8_t   SCF_shift[256];
 126 #endif
 127
 128     MPC_SAMPLE_FORMAT V_L[MPC_V_MEM + 960];
 129     MPC_SAMPLE_FORMAT V_R[MPC_V_MEM + 960];
 130     MPC_SAMPLE_FORMAT (*Y_L)[32];
 131     MPC_SAMPLE_FORMAT (*Y_R)[32];
 132     MPC_SAMPLE_FORMAT SCF[256]; ///< holds adapted scalefactors (for clipping prevention)
 133     //@}
 134
 135 } mpc_decoder;
 136
 137 #endif // _mpc_decoder_h