getvlc.h

MPEG2视频编解码算法方面的源代码(包括编码和解码)

/* getvlc.h, variable length code tables                                    */

/* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. */

/*
 * Disclaimer of Warranty
 *
 * These software programs are available to the user without any license fee or
 * royalty on an "as is" basis.  The MPEG Software Simulation Group disclaims
 * any and all warranties, whether express, implied, or statuary, including any
 * implied warranties or merchantability or of fitness for a particular
 * purpose.  In no event shall the copyright-holder be liable for any
 * incidental, punitive, or consequential damages of any kind whatsoever
 * arising from the use of these programs.
 *
 * This disclaimer of warranty extends to the user of these programs and user's
 * customers, employees, agents, transferees, successors, and assigns.
 *
 * The MPEG Software Simulation Group does not represent or warrant that the
 * programs furnished hereunder are free of infringement of any third-party
 * patents.
 *
 * Commercial implementations of MPEG-1 and MPEG-2 video, including shareware,
 * are subject to royalty fees to patent holders.  Many of these patents are
 * general enough such that they are unavoidable regardless of implementation
 * design.
 *
 */

/* NOTE: #define constants such as MACROBLOCK_QUANT are upper case 
   as per C programming convention. However, the MPEG document 
   (ISO/IEC 13818-2) lists them in all lower case (e.g. Annex B) */

/* NOTE: the VLC tables are in a flash format---a transformation
   of the tables in Annex B to a form more convenient towards 
   parallel (more than one-bit-at-a-time) decoding */

typedef struct {
  char val, len;
} VLCtab;

typedef struct {
  char run, level, len;
} DCTtab;

/* Table B-3, macroblock_type in P-pictures, codes 001..1xx */
static VLCtab PMBtab0[8] = {
  {ERROR,0},
  {MACROBLOCK_MOTION_FORWARD,3},
  {MACROBLOCK_PATTERN,2}, {MACROBLOCK_PATTERN,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,1}, 
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,1},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,1}, 
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,1}
};

/* Table B-3, macroblock_type in P-pictures, codes 000001..00011x */
static VLCtab PMBtab1[8] = {
  {ERROR,0},
  {MACROBLOCK_QUANT|MACROBLOCK_INTRA,6},
  {MACROBLOCK_QUANT|MACROBLOCK_PATTERN,5}, {MACROBLOCK_QUANT|MACROBLOCK_PATTERN,5},
  {MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,5}, {MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,5},
  {MACROBLOCK_INTRA,5}, {MACROBLOCK_INTRA,5}
};

/* Table B-4, macroblock_type in B-pictures, codes 0010..11xx */
static VLCtab BMBtab0[16] = {
  {ERROR,0}, 
  {ERROR,0},
  {MACROBLOCK_MOTION_FORWARD,4},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,4},
  {MACROBLOCK_MOTION_BACKWARD,3}, 
  {MACROBLOCK_MOTION_BACKWARD,3},
  {MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,3}, 
  {MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,3},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD,2}, 
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD,2}, 
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,2}
};

/* Table B-4, macroblock_type in B-pictures, codes 000001..00011x */
static VLCtab BMBtab1[8] = {
  {ERROR,0},
  {MACROBLOCK_QUANT|MACROBLOCK_INTRA,6},
  {MACROBLOCK_QUANT|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,6},
  {MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,6},
  {MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,5},
  {MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,5},
  {MACROBLOCK_INTRA,5}, 
  {MACROBLOCK_INTRA,5}
};

/* Table B-5, macroblock_type in spat. scal. I-pictures, codes 0001..1xxx */
static VLCtab spIMBtab[16] = {
  {ERROR,0},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS,4},
  {MACROBLOCK_QUANT|MACROBLOCK_INTRA,4},
  {MACROBLOCK_INTRA,4},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_QUANT|MACROBLOCK_PATTERN,2}, {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_QUANT|MACROBLOCK_PATTERN,2},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_QUANT|MACROBLOCK_PATTERN,2}, {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_QUANT|MACROBLOCK_PATTERN,2},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_PATTERN,1}, {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_PATTERN,1},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_PATTERN,1}, {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_PATTERN,1},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_PATTERN,1}, {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_PATTERN,1},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_PATTERN,1}, {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_PATTERN,1}
};

/* Table B-6, macroblock_type in spat. scal. P-pictures, codes 0010..11xx */
static VLCtab spPMBtab0[16] =
{
  {ERROR,0},
  {ERROR,0},
  {MACROBLOCK_MOTION_FORWARD,4},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_FORWARD,4},
  {MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,3}, {MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,3},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,3}, {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,3},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,2}, 
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,2}, 
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,2},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,2},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,2},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,2},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,2}
};

/* Table B-6, macroblock_type in spat. scal. P-pictures, codes 0000010..000111x */
static VLCtab spPMBtab1[16] = {
  {ERROR,0},
  {ERROR,0},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_QUANT|MACROBLOCK_PATTERN,7},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS,7},
  {MACROBLOCK_PATTERN,7},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_PATTERN,7},
  {MACROBLOCK_QUANT|MACROBLOCK_INTRA,7},
  {MACROBLOCK_INTRA,7},
  {MACROBLOCK_QUANT|MACROBLOCK_PATTERN,6}, 
  {MACROBLOCK_QUANT|MACROBLOCK_PATTERN,6},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_QUANT|MACROBLOCK_PATTERN,6}, 
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_QUANT|MACROBLOCK_PATTERN,6},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG,6}, 
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG,6},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_PATTERN,6}, 
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_PATTERN,6}
};

/* Table B-7, macroblock_type in spat. scal. B-pictures, codes 0010..11xx */
static VLCtab spBMBtab0[14] = {
  {MACROBLOCK_MOTION_FORWARD,4},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,4},
  {MACROBLOCK_MOTION_BACKWARD,3}, 
  {MACROBLOCK_MOTION_BACKWARD,3},
  {MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,3}, 
  {MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,3},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD,2}, 
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD,2}, 
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,2},
  {MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,2}
};

/* Table B-7, macroblock_type in spat. scal. B-pictures, codes 0000100..000111x */
static VLCtab spBMBtab1[12] = {
  {MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,7},
  {MACROBLOCK_QUANT|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,7},
  {MACROBLOCK_INTRA,7},
  {MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,7},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_FORWARD,6}, 
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_FORWARD,6},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,6}, 
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,6},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_BACKWARD,6}, 
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_BACKWARD,6},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,6}, 
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,6}
};

/* Table B-7, macroblock_type in spat. scal. B-pictures, codes 00000100x..000001111 */
static VLCtab spBMBtab2[8] = {
  {MACROBLOCK_QUANT|MACROBLOCK_INTRA,8}, 
  {MACROBLOCK_QUANT|MACROBLOCK_INTRA,8},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,8},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_QUANT|MACROBLOCK_MOTION_FORWARD|MACROBLOCK_PATTERN,8},
  {SPATIAL_TEMPORAL_WEIGHT_CODE_FLAG|MACROBLOCK_QUANT|MACROBLOCK_MOTION_BACKWARD|MACROBLOCK_PATTERN,9},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_QUANT|MACROBLOCK_PATTERN,9},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS,9},
  {PERMITTED_SPATIAL_TEMPORAL_WEIGHT_CLASS|MACROBLOCK_PATTERN,9}
};

/* Table B-8, macroblock_type in spat. scal. B-pictures, codes 001..1xx */
static VLCtab SNRMBtab[8] = {
  {ERROR,0},
  {0,3},
  {MACROBLOCK_QUANT|MACROBLOCK_PATTERN,2}, 
  {MACROBLOCK_QUANT|MACROBLOCK_PATTERN,2},
  {MACROBLOCK_PATTERN,1}, 
  {MACROBLOCK_PATTERN,1}, 
  {MACROBLOCK_PATTERN,1}, 
  {MACROBLOCK_PATTERN,1}
};

/* Table B-10, motion_code, codes 0001 ... 01xx */
static VLCtab MVtab0[8] =
{ {ERROR,0}, {3,3}, {2,2}, {2,2}, {1,1}, {1,1}, {1,1}, {1,1}
};

/* Table B-10, motion_code, codes 0000011 ... 000011x */
static VLCtab MVtab1[8] =
{ {ERROR,0}, {ERROR,0}, {ERROR,0}, {7,6}, {6,6}, {5,6}, {4,5}, {4,5}
};

/* Table B-10, motion_code, codes 0000001100 ... 000001011x */
static VLCtab MVtab2[12] =
{ {16,9}, {15,9}, {14,9}, {13,9},
  {12,9}, {11,9}, {10,8}, {10,8},
  {9,8},  {9,8},  {8,8},  {8,8}
};

/* Table B-9, coded_block_pattern, codes 01000 ... 111xx */
static VLCtab CBPtab0[32] =
{ {ERROR,0}, {ERROR,0}, {ERROR,0}, {ERROR,0},
  {ERROR,0}, {ERROR,0}, {ERROR,0}, {ERROR,0},
  {62,5}, {2,5},  {61,5}, {1,5},  {56,5}, {52,5}, {44,5}, {28,5},
  {40,5}, {20,5}, {48,5}, {12,5}, {32,4}, {32,4}, {16,4}, {16,4},
  {8,4},  {8,4},  {4,4},  {4,4},  {60,3}, {60,3}, {60,3}, {60,3}
};

/* Table B-9, coded_block_pattern, codes 00000100 ... 001111xx */
static VLCtab CBPtab1[64] =
{ {ERROR,0}, {ERROR,0}, {ERROR,0}, {ERROR,0},
  {58,8}, {54,8}, {46,8}, {30,8},
  {57,8}, {53,8}, {45,8}, {29,8}, {38,8}, {26,8}, {37,8}, {25,8},
  {43,8}, {23,8}, {51,8}, {15,8}, {42,8}, {22,8}, {50,8}, {14,8},
  {41,8}, {21,8}, {49,8}, {13,8}, {35,8}, {19,8}, {11,8}, {7,8},
  {34,7}, {34,7}, {18,7}, {18,7}, {10,7}, {10,7}, {6,7},  {6,7},
  {33,7}, {33,7}, {17,7}, {17,7}, {9,7},  {9,7},  {5,7},  {5,7},
  {63,6}, {63,6}, {63,6}, {63,6}, {3,6},  {3,6},  {3,6},  {3,6},
  {36,6}, {36,6}, {36,6}, {36,6}, {24,6}, {24,6}, {24,6}, {24,6}
};