falkTX
/
FFmpeg
mirror of https://github.com/falkTX/FFmpeg.git
1
0
Fork 0
Code Issues 0 Releases 338 Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
36074 Commits
32 Branches
922MB
Tree: 185c2ef849
Branches Tags
${ item.name }
Create branch ${ searchTerm }
from '185c2ef849'
${ noResults }
FFmpeg/libavcodec/cavsdec.c

1206 lines
54KB
Raw Blame History 

  1. /*

  2.  * Chinese AVS video (AVS1-P2, JiZhun profile) decoder.

  3.  * Copyright (c) 2006  Stefan Gehrer <stefan.gehrer@gmx.de>

  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.  * Chinese AVS video (AVS1-P2, JiZhun profile) decoder

  25.  * @author Stefan Gehrer <stefan.gehrer@gmx.de>

  26.  */

  27. 

  28. #include "avcodec.h"

  29. #include "get_bits.h"

  30. #include "golomb.h"

  31. #include "cavs.h"

  32. #include "internal.h"

  33. 

  34. static const uint8_t mv_scan[4] = {

  35.     MV_FWD_X0, MV_FWD_X1,

  36.     MV_FWD_X2, MV_FWD_X3

  37. };

  38. 

  39. static const uint8_t cbp_tab[64][2] = {

  40.   { 63,  0 }, { 15, 15 }, { 31, 63 }, { 47, 31 }, {  0, 16 }, { 14, 32 }, { 13, 47 }, { 11, 13 },

  41.   {  7, 14 }, {  5, 11 }, { 10, 12 }, {  8,  5 }, { 12, 10 }, { 61,  7 }, {  4, 48 }, { 55,  3 },

  42.   {  1,  2 }, {  2,  8 }, { 59,  4 }, {  3,  1 }, { 62, 61 }, {  9, 55 }, {  6, 59 }, { 29, 62 },

  43.   { 45, 29 }, { 51, 27 }, { 23, 23 }, { 39, 19 }, { 27, 30 }, { 46, 28 }, { 53,  9 }, { 30,  6 },

  44.   { 43, 60 }, { 37, 21 }, { 60, 44 }, { 16, 26 }, { 21, 51 }, { 28, 35 }, { 19, 18 }, { 35, 20 },

  45.   { 42, 24 }, { 26, 53 }, { 44, 17 }, { 32, 37 }, { 58, 39 }, { 24, 45 }, { 20, 58 }, { 17, 43 },

  46.   { 18, 42 }, { 48, 46 }, { 22, 36 }, { 33, 33 }, { 25, 34 }, { 49, 40 }, { 40, 52 }, { 36, 49 },

  47.   { 34, 50 }, { 50, 56 }, { 52, 25 }, { 54, 22 }, { 41, 54 }, { 56, 57 }, { 38, 41 }, { 57, 38 }

  48. };

  49. 

  50. static const uint8_t scan3x3[4] = { 4, 5, 7, 8 };

  51. 

  52. static const uint8_t cavs_chroma_qp[64] = {

  53.    0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,

  54.   16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,

  55.   32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 42, 43, 43, 44, 44,

  56.   45, 45, 46, 46, 47, 47, 48, 48, 48, 49, 49, 49, 50, 50, 50, 51

  57. };

  58. 

  59. static const uint8_t dequant_shift[64] = {

  60.   14, 14, 14, 14, 14, 14, 14, 14,

  61.   13, 13, 13, 13, 13, 13, 13, 13,

  62.   13, 12, 12, 12, 12, 12, 12, 12,

  63.   11, 11, 11, 11, 11, 11, 11, 11,

  64.   11, 10, 10, 10, 10, 10, 10, 10,

  65.   10,  9,  9,  9,  9,  9,  9,  9,

  66.   9,   8,  8,  8,  8,  8,  8,  8,

  67.   7,   7,  7,  7,  7,  7,  7,  7

  68. };

  69. 

  70. static const uint16_t dequant_mul[64] = {

  71.   32768, 36061, 38968, 42495, 46341, 50535, 55437, 60424,

  72.   32932, 35734, 38968, 42495, 46177, 50535, 55109, 59933,

  73.   65535, 35734, 38968, 42577, 46341, 50617, 55027, 60097,

  74.   32809, 35734, 38968, 42454, 46382, 50576, 55109, 60056,

  75.   65535, 35734, 38968, 42495, 46320, 50515, 55109, 60076,

  76.   65535, 35744, 38968, 42495, 46341, 50535, 55099, 60087,

  77.   65535, 35734, 38973, 42500, 46341, 50535, 55109, 60097,

  78.   32771, 35734, 38965, 42497, 46341, 50535, 55109, 60099

  79. };

  80. 

  81. #define EOB 0, 0, 0

  82. 

  83. static const struct dec_2dvlc intra_dec[7] = {

  84.     {

  85.         { //level / run / table_inc

  86.             {  1,  1,  1 }, { -1,  1,  1 }, {  1,  2,  1 }, { -1,  2,  1 }, {  1,  3,  1 }, { -1,  3, 1 },

  87.             {  1,  4,  1 }, { -1,  4,  1 }, {  1,  5,  1 }, { -1,  5,  1 }, {  1,  6,  1 }, { -1,  6, 1 },

  88.             {  1,  7,  1 }, { -1,  7,  1 }, {  1,  8,  1 }, { -1,  8,  1 }, {  1,  9,  1 }, { -1,  9, 1 },

  89.             {  1, 10,  1 }, { -1, 10,  1 }, {  1, 11,  1 }, { -1, 11,  1 }, {  2,  1,  2 }, { -2,  1, 2 },

  90.             {  1, 12,  1 }, { -1, 12,  1 }, {  1, 13,  1 }, { -1, 13,  1 }, {  1, 14,  1 }, { -1, 14, 1 },

  91.             {  1, 15,  1 }, { -1, 15,  1 }, {  2,  2,  2 }, { -2,  2,  2 }, {  1, 16,  1 }, { -1, 16, 1 },

  92.             {  1, 17,  1 }, { -1, 17,  1 }, {  3,  1,  3 }, { -3,  1,  3 }, {  1, 18,  1 }, { -1, 18, 1 },

  93.             {  1, 19,  1 }, { -1, 19,  1 }, {  2,  3,  2 }, { -2,  3,  2 }, {  1, 20,  1 }, { -1, 20, 1 },

  94.             {  1, 21,  1 }, { -1, 21,  1 }, {  2,  4,  2 }, { -2,  4,  2 }, {  1, 22,  1 }, { -1, 22, 1 },

  95.             {  2,  5,  2 }, { -2,  5,  2 }, {  1, 23,  1 }, { -1, 23,  1 }, {   EOB    }

  96.         },

  97.         //level_add

  98.         { 0, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, -1, -1, -1 },

  99.         2, //golomb_order

  100.         0, //inc_limit

  101.         23, //max_run

  102.     },

  103.     {

  104.         { //level / run

  105.             {  1,  1,  0 }, { -1,  1,  0 }, {  1,  2,  0 }, { -1,  2,  0 }, {  2,  1,  1 }, { -2,  1,  1 },

  106.             {  1,  3,  0 }, { -1,  3,  0 }, {     EOB    }, {  1,  4,  0 }, { -1,  4,  0 }, {  1,  5,  0 },

  107.             { -1,  5,  0 }, {  1,  6,  0 }, { -1,  6,  0 }, {  3,  1,  2 }, { -3,  1,  2 }, {  2,  2,  1 },

  108.             { -2,  2,  1 }, {  1,  7,  0 }, { -1,  7,  0 }, {  1,  8,  0 }, { -1,  8,  0 }, {  1,  9,  0 },

  109.             { -1,  9,  0 }, {  2,  3,  1 }, { -2,  3,  1 }, {  4,  1,  2 }, { -4,  1,  2 }, {  1, 10,  0 },

  110.             { -1, 10,  0 }, {  1, 11,  0 }, { -1, 11,  0 }, {  2,  4,  1 }, { -2,  4,  1 }, {  3,  2,  2 },

  111.             { -3,  2,  2 }, {  1, 12,  0 }, { -1, 12,  0 }, {  2,  5,  1 }, { -2,  5,  1 }, {  5,  1,  3 },

  112.             { -5,  1,  3 }, {  1, 13,  0 }, { -1, 13,  0 }, {  2,  6,  1 }, { -2,  6,  1 }, {  1, 14,  0 },

  113.             { -1, 14,  0 }, {  2,  7,  1 }, { -2,  7,  1 }, {  2,  8,  1 }, { -2,  8,  1 }, {  3,  3,  2 },

  114.             { -3,  3,  2 }, {  6,  1,  3 }, { -6,  1,  3 }, {  1, 15,  0 }, { -1, 15,  0 }

  115.         },

  116.         //level_add

  117.         { 0, 7, 4, 4, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  118.         2, //golomb_order

  119.         1, //inc_limit

  120.         15, //max_run

  121.     },

  122.     {

  123.         { //level / run

  124.             {  1,  1,  0 }, { -1,  1,  0 }, {  2,  1,  0 }, { -2,  1,  0 }, {  1,  2,  0 }, { -1,  2,  0 },

  125.             {  3,  1,  1 }, { -3,  1,  1 }, {     EOB    }, {  1,  3,  0 }, { -1,  3,  0 }, {  2,  2,  0 },

  126.             { -2,  2,  0 }, {  4,  1,  1 }, { -4,  1,  1 }, {  1,  4,  0 }, { -1,  4,  0 }, {  5,  1,  2 },

  127.             { -5,  1,  2 }, {  1,  5,  0 }, { -1,  5,  0 }, {  3,  2,  1 }, { -3,  2,  1 }, {  2,  3,  0 },

  128.             { -2,  3,  0 }, {  1,  6,  0 }, { -1,  6,  0 }, {  6,  1,  2 }, { -6,  1,  2 }, {  2,  4,  0 },

  129.             { -2,  4,  0 }, {  1,  7,  0 }, { -1,  7,  0 }, {  4,  2,  1 }, { -4,  2,  1 }, {  7,  1,  2 },

  130.             { -7,  1,  2 }, {  3,  3,  1 }, { -3,  3,  1 }, {  2,  5,  0 }, { -2,  5,  0 }, {  1,  8,  0 },

  131.             { -1,  8,  0 }, {  2,  6,  0 }, { -2,  6,  0 }, {  8,  1,  3 }, { -8,  1,  3 }, {  1,  9,  0 },

  132.             { -1,  9,  0 }, {  5,  2,  2 }, { -5,  2,  2 }, {  3,  4,  1 }, { -3,  4,  1 }, {  2,  7,  0 },

  133.             { -2,  7,  0 }, {  9,  1,  3 }, { -9,  1,  3 }, {  1, 10,  0 }, { -1, 10,  0 }

  134.         },

  135.         //level_add

  136.         { 0, 10, 6, 4, 4, 3, 3, 3, 2, 2, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  137.         2, //golomb_order

  138.         2, //inc_limit

  139.         10, //max_run

  140.     },

  141.     {

  142.         { //level / run

  143.             {  1,  1,  0 }, { -1,  1,  0 }, {  2,  1,  0 }, { -2,  1,  0 }, {  3,  1,  0 }, { -3,  1,  0 },

  144.             {  1,  2,  0 }, { -1,  2,  0 }, {     EOB    }, {  4,  1,  0 }, { -4,  1,  0 }, {  5,  1,  1 },

  145.             { -5,  1,  1 }, {  2,  2,  0 }, { -2,  2,  0 }, {  1,  3,  0 }, { -1,  3,  0 }, {  6,  1,  1 },

  146.             { -6,  1,  1 }, {  3,  2,  0 }, { -3,  2,  0 }, {  7,  1,  1 }, { -7,  1,  1 }, {  1,  4,  0 },

  147.             { -1,  4,  0 }, {  8,  1,  2 }, { -8,  1,  2 }, {  2,  3,  0 }, { -2,  3,  0 }, {  4,  2,  0 },

  148.             { -4,  2,  0 }, {  1,  5,  0 }, { -1,  5,  0 }, {  9,  1,  2 }, { -9,  1,  2 }, {  5,  2,  1 },

  149.             { -5,  2,  1 }, {  2,  4,  0 }, { -2,  4,  0 }, { 10,  1,  2 }, {-10,  1,  2 }, {  3,  3,  0 },

  150.             { -3,  3,  0 }, {  1,  6,  0 }, { -1,  6,  0 }, { 11,  1,  3 }, {-11,  1,  3 }, {  6,  2,  1 },

  151.             { -6,  2,  1 }, {  1,  7,  0 }, { -1,  7,  0 }, {  2,  5,  0 }, { -2,  5,  0 }, {  3,  4,  0 },

  152.             { -3,  4,  0 }, { 12,  1,  3 }, {-12,  1,  3 }, {  4,  3,  0 }, { -4,  3,  0 }

  153.          },

  154.         //level_add

  155.         { 0, 13, 7, 5, 4, 3, 2, 2, -1, -1, -1 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  156.         2, //golomb_order

  157.         4, //inc_limit

  158.         7, //max_run

  159.     },

  160.     {

  161.         { //level / run

  162.             {  1,  1,  0 }, { -1,  1,  0 }, {  2,  1,  0 }, { -2,  1,  0 }, {  3,  1,  0 }, { -3,  1,  0 },

  163.             {     EOB    }, {  4,  1,  0 }, { -4,  1,  0 }, {  5,  1,  0 }, { -5,  1,  0 }, {  6,  1,  0 },

  164.             { -6,  1,  0 }, {  1,  2,  0 }, { -1,  2,  0 }, {  7,  1,  0 }, { -7,  1,  0 }, {  8,  1,  1 },

  165.             { -8,  1,  1 }, {  2,  2,  0 }, { -2,  2,  0 }, {  9,  1,  1 }, { -9,  1,  1 }, { 10,  1,  1 },

  166.             {-10,  1,  1 }, {  1,  3,  0 }, { -1,  3,  0 }, {  3,  2,  0 }, { -3,  2,  0 }, { 11,  1,  2 },

  167.             {-11,  1,  2 }, {  4,  2,  0 }, { -4,  2,  0 }, { 12,  1,  2 }, {-12,  1,  2 }, { 13,  1,  2 },

  168.             {-13,  1,  2 }, {  5,  2,  0 }, { -5,  2,  0 }, {  1,  4,  0 }, { -1,  4,  0 }, {  2,  3,  0 },

  169.             { -2,  3,  0 }, { 14,  1,  2 }, {-14,  1,  2 }, {  6,  2,  0 }, { -6,  2,  0 }, { 15,  1,  2 },

  170.             {-15,  1,  2 }, { 16,  1,  2 }, {-16,  1,  2 }, {  3,  3,  0 }, { -3,  3,  0 }, {  1,  5,  0 },

  171.             { -1,  5,  0 }, {  7,  2,  0 }, { -7,  2,  0 }, { 17,  1,  2 }, {-17,  1,  2 }

  172.         },

  173.         //level_add

  174.         { 0,18, 8, 4, 2, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  175.         2, //golomb_order

  176.         7, //inc_limit

  177.         5, //max_run

  178.     },

  179.     {

  180.         { //level / run

  181.             {     EOB    }, {  1,  1,  0 }, { -1,  1,  0 }, {  2,  1,  0 }, { -2,  1,  0 }, {  3,  1,  0 },

  182.             { -3,  1,  0 }, {  4,  1,  0 }, { -4,  1,  0 }, {  5,  1,  0 }, { -5,  1,  0 }, {  6,  1,  0 },

  183.             { -6,  1,  0 }, {  7,  1,  0 }, { -7,  1,  0 }, {  8,  1,  0 }, { -8,  1,  0 }, {  9,  1,  0 },

  184.             { -9,  1,  0 }, { 10,  1,  0 }, {-10,  1,  0 }, {  1,  2,  0 }, { -1,  2,  0 }, { 11,  1,  1 },

  185.             {-11,  1,  1 }, { 12,  1,  1 }, {-12,  1,  1 }, { 13,  1,  1 }, {-13,  1,  1 }, {  2,  2,  0 },

  186.             { -2,  2,  0 }, { 14,  1,  1 }, {-14,  1,  1 }, { 15,  1,  1 }, {-15,  1,  1 }, {  3,  2,  0 },

  187.             { -3,  2,  0 }, { 16,  1,  1 }, {-16,  1,  1 }, {  1,  3,  0 }, { -1,  3,  0 }, { 17,  1,  1 },

  188.             {-17,  1,  1 }, {  4,  2,  0 }, { -4,  2,  0 }, { 18,  1,  1 }, {-18,  1,  1 }, {  5,  2,  0 },

  189.             { -5,  2,  0 }, { 19,  1,  1 }, {-19,  1,  1 }, { 20,  1,  1 }, {-20,  1,  1 }, {  6,  2,  0 },

  190.             { -6,  2,  0 }, { 21,  1,  1 }, {-21,  1,  1 }, {  2,  3,  0 }, { -2,  3,  0 }

  191.         },

  192.         //level_add

  193.         { 0, 22, 7, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  194.         2, //golomb_order

  195.         10, //inc_limit

  196.         3, //max_run

  197.     },

  198.     {

  199.         { //level / run

  200.             {     EOB    }, {  1,  1,  0 }, { -1,  1,  0 }, {  2,  1,  0 }, { -2,  1,  0 }, {  3,  1,  0 },

  201.             { -3,  1,  0 }, {  4,  1,  0 }, { -4,  1,  0 }, {  5,  1,  0 }, { -5,  1,  0 }, {  6,  1,  0 },

  202.             { -6,  1,  0 }, {  7,  1,  0 }, { -7,  1,  0 }, {  8,  1,  0 }, { -8,  1,  0 }, {  9,  1,  0 },

  203.             { -9,  1,  0 }, { 10,  1,  0 }, {-10,  1,  0 }, { 11,  1,  0 }, {-11,  1,  0 }, { 12,  1,  0 },

  204.             {-12,  1,  0 }, { 13,  1,  0 }, {-13,  1,  0 }, { 14,  1,  0 }, {-14,  1,  0 }, { 15,  1,  0 },

  205.             {-15,  1,  0 }, { 16,  1,  0 }, {-16,  1,  0 }, {  1,  2,  0 }, { -1,  2,  0 }, { 17,  1,  0 },

  206.             {-17,  1,  0 }, { 18,  1,  0 }, {-18,  1,  0 }, { 19,  1,  0 }, {-19,  1,  0 }, { 20,  1,  0 },

  207.             {-20,  1,  0 }, { 21,  1,  0 }, {-21,  1,  0 }, {  2,  2,  0 }, { -2,  2,  0 }, { 22,  1,  0 },

  208.             {-22,  1,  0 }, { 23,  1,  0 }, {-23,  1,  0 }, { 24,  1,  0 }, {-24,  1,  0 }, { 25,  1,  0 },

  209.             {-25,  1,  0 }, {  3,  2,  0 }, { -3,  2,  0 }, { 26,  1,  0 }, {-26,  1,  0 }

  210.         },

  211.         //level_add

  212.         { 0, 27, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  213.         2, //golomb_order

  214.         INT_MAX, //inc_limit

  215.         2, //max_run

  216.     }

  217. };

  218. 

  219. static const struct dec_2dvlc inter_dec[7] = {

  220.     {

  221.         { //level / run

  222.             {  1,  1,  1 }, { -1,  1,  1 }, {  1,  2,  1 }, { -1,  2,  1 }, {  1,  3,  1 }, { -1,  3,  1 },

  223.             {  1,  4,  1 }, { -1,  4,  1 }, {  1,  5,  1 }, { -1,  5,  1 }, {  1,  6,  1 }, { -1,  6,  1 },

  224.             {  1,  7,  1 }, { -1,  7,  1 }, {  1,  8,  1 }, { -1,  8,  1 }, {  1,  9,  1 }, { -1,  9,  1 },

  225.             {  1, 10,  1 }, { -1, 10,  1 }, {  1, 11,  1 }, { -1, 11,  1 }, {  1, 12,  1 }, { -1, 12,  1 },

  226.             {  1, 13,  1 }, { -1, 13,  1 }, {  2,  1,  2 }, { -2,  1,  2 }, {  1, 14,  1 }, { -1, 14,  1 },

  227.             {  1, 15,  1 }, { -1, 15,  1 }, {  1, 16,  1 }, { -1, 16,  1 }, {  1, 17,  1 }, { -1, 17,  1 },

  228.             {  1, 18,  1 }, { -1, 18,  1 }, {  1, 19,  1 }, { -1, 19,  1 }, {  3,  1,  3 }, { -3,  1,  3 },

  229.             {  1, 20,  1 }, { -1, 20,  1 }, {  1, 21,  1 }, { -1, 21,  1 }, {  2,  2,  2 }, { -2,  2,  2 },

  230.             {  1, 22,  1 }, { -1, 22,  1 }, {  1, 23,  1 }, { -1, 23,  1 }, {  1, 24,  1 }, { -1, 24,  1 },

  231.             {  1, 25,  1 }, { -1, 25,  1 }, {  1, 26,  1 }, { -1, 26,  1 }, {   EOB    }

  232.         },

  233.         //level_add

  234.         { 0, 4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 },

  235.         3, //golomb_order

  236.         0, //inc_limit

  237.         26 //max_run

  238.     },

  239.     {

  240.         { //level / run

  241.             {  1,  1,  0 }, { -1,  1,  0 }, {     EOB    }, {  1,  2,  0 }, { -1,  2,  0 }, {  1,  3,  0 },

  242.             { -1,  3,  0 }, {  1,  4,  0 }, { -1,  4,  0 }, {  1,  5,  0 }, { -1,  5,  0 }, {  1,  6,  0 },

  243.             { -1,  6,  0 }, {  2,  1,  1 }, { -2,  1,  1 }, {  1,  7,  0 }, { -1,  7,  0 }, {  1,  8,  0 },

  244.             { -1,  8,  0 }, {  1,  9,  0 }, { -1,  9,  0 }, {  1, 10,  0 }, { -1, 10,  0 }, {  2,  2,  1 },

  245.             { -2,  2,  1 }, {  1, 11,  0 }, { -1, 11,  0 }, {  1, 12,  0 }, { -1, 12,  0 }, {  3,  1,  2 },

  246.             { -3,  1,  2 }, {  1, 13,  0 }, { -1, 13,  0 }, {  1, 14,  0 }, { -1, 14,  0 }, {  2,  3,  1 },

  247.             { -2,  3,  1 }, {  1, 15,  0 }, { -1, 15,  0 }, {  2,  4,  1 }, { -2,  4,  1 }, {  1, 16,  0 },

  248.             { -1, 16,  0 }, {  2,  5,  1 }, { -2,  5,  1 }, {  1, 17,  0 }, { -1, 17,  0 }, {  4,  1,  3 },

  249.             { -4,  1,  3 }, {  2,  6,  1 }, { -2,  6,  1 }, {  1, 18,  0 }, { -1, 18,  0 }, {  1, 19,  0 },

  250.             { -1, 19,  0 }, {  2,  7,  1 }, { -2,  7,  1 }, {  3,  2,  2 }, { -3,  2,  2 }

  251.         },

  252.         //level_add

  253.         { 0, 5, 4, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, -1, -1, -1, -1, -1, -1, -1 },

  254.         2, //golomb_order

  255.         1, //inc_limit

  256.         19 //max_run

  257.     },

  258.     {

  259.         { //level / run

  260.             {  1,  1,  0 }, { -1,  1,  0 }, {     EOB    }, {  1,  2,  0 }, { -1,  2,  0 }, {  2,  1,  0 },

  261.             { -2,  1,  0 }, {  1,  3,  0 }, { -1,  3,  0 }, {  1,  4,  0 }, { -1,  4,  0 }, {  3,  1,  1 },

  262.             { -3,  1,  1 }, {  2,  2,  0 }, { -2,  2,  0 }, {  1,  5,  0 }, { -1,  5,  0 }, {  1,  6,  0 },

  263.             { -1,  6,  0 }, {  1,  7,  0 }, { -1,  7,  0 }, {  2,  3,  0 }, { -2,  3,  0 }, {  4,  1,  2 },

  264.             { -4,  1,  2 }, {  1,  8,  0 }, { -1,  8,  0 }, {  3,  2,  1 }, { -3,  2,  1 }, {  2,  4,  0 },

  265.             { -2,  4,  0 }, {  1,  9,  0 }, { -1,  9,  0 }, {  1, 10,  0 }, { -1, 10,  0 }, {  5,  1,  2 },

  266.             { -5,  1,  2 }, {  2,  5,  0 }, { -2,  5,  0 }, {  1, 11,  0 }, { -1, 11,  0 }, {  2,  6,  0 },

  267.             { -2,  6,  0 }, {  1, 12,  0 }, { -1, 12,  0 }, {  3,  3,  1 }, { -3,  3,  1 }, {  6,  1,  2 },

  268.             { -6,  1,  2 }, {  4,  2,  2 }, { -4,  2,  2 }, {  1, 13,  0 }, { -1, 13,  0 }, {  2,  7,  0 },

  269.             { -2,  7,  0 }, {  3,  4,  1 }, { -3,  4,  1 }, {  1, 14,  0 }, { -1, 14,  0 }

  270.         },

  271.         //level_add

  272.         { 0, 7, 5, 4, 4, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  273.         2, //golomb_order

  274.         2, //inc_limit

  275.         14 //max_run

  276.     },

  277.     {

  278.         { //level / run

  279.             {  1,  1,  0 }, { -1,  1,  0 }, {     EOB    }, {  2,  1,  0 }, { -2,  1,  0 }, {  1,  2,  0 },

  280.             { -1,  2,  0 }, {  3,  1,  0 }, { -3,  1,  0 }, {  1,  3,  0 }, { -1,  3,  0 }, {  2,  2,  0 },

  281.             { -2,  2,  0 }, {  4,  1,  1 }, { -4,  1,  1 }, {  1,  4,  0 }, { -1,  4,  0 }, {  5,  1,  1 },

  282.             { -5,  1,  1 }, {  1,  5,  0 }, { -1,  5,  0 }, {  3,  2,  0 }, { -3,  2,  0 }, {  2,  3,  0 },

  283.             { -2,  3,  0 }, {  1,  6,  0 }, { -1,  6,  0 }, {  6,  1,  1 }, { -6,  1,  1 }, {  2,  4,  0 },

  284.             { -2,  4,  0 }, {  1,  7,  0 }, { -1,  7,  0 }, {  4,  2,  1 }, { -4,  2,  1 }, {  7,  1,  2 },

  285.             { -7,  1,  2 }, {  3,  3,  0 }, { -3,  3,  0 }, {  1,  8,  0 }, { -1,  8,  0 }, {  2,  5,  0 },

  286.             { -2,  5,  0 }, {  8,  1,  2 }, { -8,  1,  2 }, {  1,  9,  0 }, { -1,  9,  0 }, {  3,  4,  0 },

  287.             { -3,  4,  0 }, {  2,  6,  0 }, { -2,  6,  0 }, {  5,  2,  1 }, { -5,  2,  1 }, {  1, 10,  0 },

  288.             { -1, 10,  0 }, {  9,  1,  2 }, { -9,  1,  2 }, {  4,  3,  1 }, { -4,  3,  1 }

  289.         },

  290.         //level_add

  291.         { 0,10, 6, 5, 4, 3, 3, 2, 2, 2, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  292.         2, //golomb_order

  293.         3, //inc_limit

  294.         10 //max_run

  295.     },

  296.     {

  297.         { //level / run

  298.             {  1,  1,  0 }, { -1,  1,  0 }, {     EOB    }, {  2,  1,  0 }, { -2,  1,  0 }, {  3,  1,  0 },

  299.             { -3,  1,  0 }, {  1,  2,  0 }, { -1,  2,  0 }, {  4,  1,  0 }, { -4,  1,  0 }, {  5,  1,  0 },

  300.             { -5,  1,  0 }, {  2,  2,  0 }, { -2,  2,  0 }, {  1,  3,  0 }, { -1,  3,  0 }, {  6,  1,  0 },

  301.             { -6,  1,  0 }, {  3,  2,  0 }, { -3,  2,  0 }, {  7,  1,  1 }, { -7,  1,  1 }, {  1,  4,  0 },

  302.             { -1,  4,  0 }, {  8,  1,  1 }, { -8,  1,  1 }, {  2,  3,  0 }, { -2,  3,  0 }, {  4,  2,  0 },

  303.             { -4,  2,  0 }, {  1,  5,  0 }, { -1,  5,  0 }, {  9,  1,  1 }, { -9,  1,  1 }, {  5,  2,  0 },

  304.             { -5,  2,  0 }, {  2,  4,  0 }, { -2,  4,  0 }, {  1,  6,  0 }, { -1,  6,  0 }, { 10,  1,  2 },

  305.             {-10,  1,  2 }, {  3,  3,  0 }, { -3,  3,  0 }, { 11,  1,  2 }, {-11,  1,  2 }, {  1,  7,  0 },

  306.             { -1,  7,  0 }, {  6,  2,  0 }, { -6,  2,  0 }, {  3,  4,  0 }, { -3,  4,  0 }, {  2,  5,  0 },

  307.             { -2,  5,  0 }, { 12,  1,  2 }, {-12,  1,  2 }, {  4,  3,  0 }, { -4,  3,  0 }

  308.         },

  309.         //level_add

  310.         { 0, 13, 7, 5, 4, 3, 2, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  311.         2, //golomb_order

  312.         6, //inc_limit

  313.         7  //max_run

  314.     },

  315.     {

  316.         { //level / run

  317.             {      EOB    }, {  1,  1,  0 }, {  -1,  1,  0 }, {  2,  1,  0 }, {  -2,  1,  0 }, {  3,  1,  0 },

  318.             {  -3,  1,  0 }, {  4,  1,  0 }, {  -4,  1,  0 }, {  5,  1,  0 }, {  -5,  1,  0 }, {  1,  2,  0 },

  319.             {  -1,  2,  0 }, {  6,  1,  0 }, {  -6,  1,  0 }, {  7,  1,  0 }, {  -7,  1,  0 }, {  8,  1,  0 },

  320.             {  -8,  1,  0 }, {  2,  2,  0 }, {  -2,  2,  0 }, {  9,  1,  0 }, {  -9,  1,  0 }, {  1,  3,  0 },

  321.             {  -1,  3,  0 }, { 10,  1,  1 }, { -10,  1,  1 }, {  3,  2,  0 }, {  -3,  2,  0 }, { 11,  1,  1 },

  322.             { -11,  1,  1 }, {  4,  2,  0 }, {  -4,  2,  0 }, { 12,  1,  1 }, { -12,  1,  1 }, {  1,  4,  0 },

  323.             {  -1,  4,  0 }, {  2,  3,  0 }, {  -2,  3,  0 }, { 13,  1,  1 }, { -13,  1,  1 }, {  5,  2,  0 },

  324.             {  -5,  2,  0 }, { 14,  1,  1 }, { -14,  1,  1 }, {  6,  2,  0 }, {  -6,  2,  0 }, {  1,  5,  0 },

  325.             {  -1,  5,  0 }, { 15,  1,  1 }, { -15,  1,  1 }, {  3,  3,  0 }, {  -3,  3,  0 }, { 16,  1,  1 },

  326.             { -16,  1,  1 }, {  2,  4,  0 }, {  -2,  4,  0 }, {  7,  2,  0 }, {  -7,  2,  0 }

  327.         },

  328.         //level_add

  329.         { 0, 17, 8, 4, 3, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  330.         2, //golomb_order

  331.         9, //inc_limit

  332.         5  //max_run

  333.     },

  334.     {

  335.         { //level / run

  336.             {      EOB    }, {  1,  1,  0 }, {  -1,  1,  0 }, {  2,  1,  0 }, {  -2,  1,  0 }, {   3,  1,  0 },

  337.             {  -3,  1,  0 }, {  4,  1,  0 }, {  -4,  1,  0 }, {  5,  1,  0 }, {  -5,  1,  0 }, {   6,  1,  0 },

  338.             {  -6,  1,  0 }, {  7,  1,  0 }, {  -7,  1,  0 }, {  1,  2,  0 }, {  -1,  2,  0 }, {   8,  1,  0 },

  339.             {  -8,  1,  0 }, {  9,  1,  0 }, {  -9,  1,  0 }, { 10,  1,  0 }, { -10,  1,  0 }, {  11,  1,  0 },

  340.             { -11,  1,  0 }, { 12,  1,  0 }, { -12,  1,  0 }, {  2,  2,  0 }, {  -2,  2,  0 }, {  13,  1,  0 },

  341.             { -13,  1,  0 }, {  1,  3,  0 }, {  -1,  3,  0 }, { 14,  1,  0 }, { -14,  1,  0 }, {  15,  1,  0 },

  342.             { -15,  1,  0 }, {  3,  2,  0 }, {  -3,  2,  0 }, { 16,  1,  0 }, { -16,  1,  0 }, {  17,  1,  0 },

  343.             { -17,  1,  0 }, { 18,  1,  0 }, { -18,  1,  0 }, {  4,  2,  0 }, {  -4,  2,  0 }, {  19,  1,  0 },

  344.             { -19,  1,  0 }, { 20,  1,  0 }, { -20,  1,  0 }, {  2,  3,  0 }, {  -2,  3,  0 }, {   1,  4,  0 },

  345.             {  -1,  4,  0 }, {  5,  2,  0 }, {  -5,  2,  0 }, { 21,  1,  0 }, { -21,  1,  0 }

  346.         },

  347.         //level_add

  348.         { 0, 22, 6, 3, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  349.         2, //golomb_order

  350.         INT_MAX, //inc_limit

  351.         4 //max_run

  352.     }

  353. };

  354. 

  355. static const struct dec_2dvlc chroma_dec[5] = {

  356.     {

  357.         { //level / run

  358.             {  1,  1,  1 }, { -1,  1,  1 }, {  1,  2,  1 }, { -1,  2,  1 }, {  1,  3,  1 }, { -1,  3,  1 },

  359.             {  1,  4,  1 }, { -1,  4,  1 }, {  1,  5,  1 }, { -1,  5,  1 }, {  1,  6,  1 }, { -1,  6,  1 },

  360.             {  1,  7,  1 }, { -1,  7,  1 }, {  2,  1,  2 }, { -2,  1,  2 }, {  1,  8,  1 }, { -1,  8,  1 },

  361.             {  1,  9,  1 }, { -1,  9,  1 }, {  1, 10,  1 }, { -1, 10,  1 }, {  1, 11,  1 }, { -1, 11,  1 },

  362.             {  1, 12,  1 }, { -1, 12,  1 }, {  1, 13,  1 }, { -1, 13,  1 }, {  1, 14,  1 }, { -1, 14,  1 },

  363.             {  1, 15,  1 }, { -1, 15,  1 }, {  3,  1,  3 }, { -3,  1,  3 }, {  1, 16,  1 }, { -1, 16,  1 },

  364.             {  1, 17,  1 }, { -1, 17,  1 }, {  1, 18,  1 }, { -1, 18,  1 }, {  1, 19,  1 }, { -1, 19,  1 },

  365.             {  1, 20,  1 }, { -1, 20,  1 }, {  1, 21,  1 }, { -1, 21,  1 }, {  1, 22,  1 }, { -1, 22,  1 },

  366.             {  2,  2,  2 }, { -2,  2,  2 }, {  1, 23,  1 }, { -1, 23,  1 }, {  1, 24,  1 }, { -1, 24,  1 },

  367.             {  1, 25,  1 }, { -1, 25,  1 }, {  4,  1,  3 }, { -4,  1,  3 }, {   EOB    }

  368.         },

  369.         //level_add

  370.         { 0, 5, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, -1 },

  371.         2, //golomb_order

  372.         0, //inc_limit

  373.         25 //max_run

  374.     },

  375.     {

  376.         { //level / run

  377.             {     EOB    }, {  1,  1,  0 }, { -1,  1,  0 }, {  1,  2,  0 }, { -1,  2,  0 }, {  2,  1,  1 },

  378.             { -2,  1,  1 }, {  1,  3,  0 }, { -1,  3,  0 }, {  1,  4,  0 }, { -1,  4,  0 }, {  1,  5,  0 },

  379.             { -1,  5,  0 }, {  1,  6,  0 }, { -1,  6,  0 }, {  3,  1,  2 }, { -3,  1,  2 }, {  1,  7,  0 },

  380.             { -1,  7,  0 }, {  1,  8,  0 }, { -1,  8,  0 }, {  2,  2,  1 }, { -2,  2,  1 }, {  1,  9,  0 },

  381.             { -1,  9,  0 }, {  1, 10,  0 }, { -1, 10,  0 }, {  1, 11,  0 }, { -1, 11,  0 }, {  4,  1,  2 },

  382.             { -4,  1,  2 }, {  1, 12,  0 }, { -1, 12,  0 }, {  1, 13,  0 }, { -1, 13,  0 }, {  1, 14,  0 },

  383.             { -1, 14,  0 }, {  2,  3,  1 }, { -2,  3,  1 }, {  1, 15,  0 }, { -1, 15,  0 }, {  2,  4,  1 },

  384.             { -2,  4,  1 }, {  5,  1,  3 }, { -5,  1,  3 }, {  3,  2,  2 }, { -3,  2,  2 }, {  1, 16,  0 },

  385.             { -1, 16,  0 }, {  1, 17,  0 }, { -1, 17,  0 }, {  1, 18,  0 }, { -1, 18,  0 }, {  2,  5,  1 },

  386.             { -2,  5,  1 }, {  1, 19,  0 }, { -1, 19,  0 }, {  1, 20,  0 }, { -1, 20,  0 }

  387.         },

  388.         //level_add

  389.         { 0, 6, 4, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, -1, -1, -1, -1, -1, -1 },

  390.         0, //golomb_order

  391.         1, //inc_limit

  392.         20 //max_run

  393.     },

  394.     {

  395.         { //level / run

  396.             {  1,  1,  0 }, { -1,  1,  0 }, {     EOB    }, {  2,  1,  0 }, { -2,  1,  0 }, {  1,  2,  0 },

  397.             { -1,  2,  0 }, {  3,  1,  1 }, { -3,  1,  1 }, {  1,  3,  0 }, { -1,  3,  0 }, {  4,  1,  1 },

  398.             { -4,  1,  1 }, {  2,  2,  0 }, { -2,  2,  0 }, {  1,  4,  0 }, { -1,  4,  0 }, {  5,  1,  2 },

  399.             { -5,  1,  2 }, {  1,  5,  0 }, { -1,  5,  0 }, {  3,  2,  1 }, { -3,  2,  1 }, {  2,  3,  0 },

  400.             { -2,  3,  0 }, {  1,  6,  0 }, { -1,  6,  0 }, {  6,  1,  2 }, { -6,  1,  2 }, {  1,  7,  0 },

  401.             { -1,  7,  0 }, {  2,  4,  0 }, { -2,  4,  0 }, {  7,  1,  2 }, { -7,  1,  2 }, {  1,  8,  0 },

  402.             { -1,  8,  0 }, {  4,  2,  1 }, { -4,  2,  1 }, {  1,  9,  0 }, { -1,  9,  0 }, {  3,  3,  1 },

  403.             { -3,  3,  1 }, {  2,  5,  0 }, { -2,  5,  0 }, {  2,  6,  0 }, { -2,  6,  0 }, {  8,  1,  2 },

  404.             { -8,  1,  2 }, {  1, 10,  0 }, { -1, 10,  0 }, {  1, 11,  0 }, { -1, 11,  0 }, {  9,  1,  2 },

  405.             { -9,  1,  2 }, {  5,  2,  2 }, { -5,  2,  2 }, {  3,  4,  1 }, { -3,  4,  1 },

  406.         },

  407.         //level_add

  408.         { 0,10, 6, 4, 4, 3, 3, 2, 2, 2, 2, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  409.         1, //golomb_order

  410.         2, //inc_limit

  411.         11 //max_run

  412.     },

  413.     {

  414.         { //level / run

  415.             {     EOB    }, {  1,  1,  0 }, { -1,  1,  0 }, {  2,  1,  0 }, { -2,  1,  0 }, {  3,  1,  0 },

  416.             { -3,  1,  0 }, {  4,  1,  0 }, { -4,  1,  0 }, {  1,  2,  0 }, { -1,  2,  0 }, {  5,  1,  1 },

  417.             { -5,  1,  1 }, {  2,  2,  0 }, { -2,  2,  0 }, {  6,  1,  1 }, { -6,  1,  1 }, {  1,  3,  0 },

  418.             { -1,  3,  0 }, {  7,  1,  1 }, { -7,  1,  1 }, {  3,  2,  0 }, { -3,  2,  0 }, {  8,  1,  1 },

  419.             { -8,  1,  1 }, {  1,  4,  0 }, { -1,  4,  0 }, {  2,  3,  0 }, { -2,  3,  0 }, {  9,  1,  1 },

  420.             { -9,  1,  1 }, {  4,  2,  0 }, { -4,  2,  0 }, {  1,  5,  0 }, { -1,  5,  0 }, { 10,  1,  1 },

  421.             {-10,  1,  1 }, {  3,  3,  0 }, { -3,  3,  0 }, {  5,  2,  1 }, { -5,  2,  1 }, {  2,  4,  0 },

  422.             { -2,  4,  0 }, { 11,  1,  1 }, {-11,  1,  1 }, {  1,  6,  0 }, { -1,  6,  0 }, { 12,  1,  1 },

  423.             {-12,  1,  1 }, {  1,  7,  0 }, { -1,  7,  0 }, {  6,  2,  1 }, { -6,  2,  1 }, { 13,  1,  1 },

  424.             {-13,  1,  1 }, {  2,  5,  0 }, { -2,  5,  0 }, {  1,  8,  0 }, { -1,  8,  0 },

  425.         },

  426.         //level_add

  427.         { 0, 14, 7, 4, 3, 3, 2, 2, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  428.         1, //golomb_order

  429.         4, //inc_limit

  430.         8  //max_run

  431.     },

  432.     {

  433.         { //level / run

  434.             {      EOB    }, {  1,  1,  0 }, {  -1,  1,  0 }, {  2,  1,  0 }, {  -2,  1,  0 }, {  3,  1,  0 },

  435.             {  -3,  1,  0 }, {  4,  1,  0 }, {  -4,  1,  0 }, {  5,  1,  0 }, {  -5,  1,  0 }, {  6,  1,  0 },

  436.             {  -6,  1,  0 }, {  7,  1,  0 }, {  -7,  1,  0 }, {  8,  1,  0 }, {  -8,  1,  0 }, {  1,  2,  0 },

  437.             {  -1,  2,  0 }, {  9,  1,  0 }, {  -9,  1,  0 }, { 10,  1,  0 }, { -10,  1,  0 }, { 11,  1,  0 },

  438.             { -11,  1,  0 }, {  2,  2,  0 }, {  -2,  2,  0 }, { 12,  1,  0 }, { -12,  1,  0 }, { 13,  1,  0 },

  439.             { -13,  1,  0 }, {  3,  2,  0 }, {  -3,  2,  0 }, { 14,  1,  0 }, { -14,  1,  0 }, {  1,  3,  0 },

  440.             {  -1,  3,  0 }, { 15,  1,  0 }, { -15,  1,  0 }, {  4,  2,  0 }, {  -4,  2,  0 }, { 16,  1,  0 },

  441.             { -16,  1,  0 }, { 17,  1,  0 }, { -17,  1,  0 }, {  5,  2,  0 }, {  -5,  2,  0 }, {  1,  4,  0 },

  442.             {  -1,  4,  0 }, {  2,  3,  0 }, {  -2,  3,  0 }, { 18,  1,  0 }, { -18,  1,  0 }, {  6,  2,  0 },

  443.             {  -6,  2,  0 }, { 19,  1,  0 }, { -19,  1,  0 }, {  1,  5,  0 }, {  -1,  5,  0 },

  444.         },

  445.         //level_add

  446.         { 0, 20, 7, 3, 2, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

  447.         0, //golomb_order

  448.         INT_MAX, //inc_limit

  449.         5, //max_run

  450.     }

  451. };

  452. 

  453. #undef EOB

  454. 

  455. /*****************************************************************************

  456.  *

  457.  * motion vector prediction

  458.  *

  459.  ****************************************************************************/

  460. 

  461. static inline void store_mvs(AVSContext *h)

  462. {

  463.     h->col_mv[h->mbidx * 4 + 0] = h->mv[MV_FWD_X0];

  464.     h->col_mv[h->mbidx * 4 + 1] = h->mv[MV_FWD_X1];

  465.     h->col_mv[h->mbidx * 4 + 2] = h->mv[MV_FWD_X2];

  466.     h->col_mv[h->mbidx * 4 + 3] = h->mv[MV_FWD_X3];

  467. }

  468. 

  469. static inline void mv_pred_direct(AVSContext *h, cavs_vector *pmv_fw,

  470.                                   cavs_vector *col_mv)

  471. {

  472.     cavs_vector *pmv_bw = pmv_fw + MV_BWD_OFFS;

  473.     int den = h->direct_den[col_mv->ref];

  474.     int m = col_mv->x >> 31;

  475. 

  476.     pmv_fw->dist = h->dist[1];

  477.     pmv_bw->dist = h->dist[0];

  478.     pmv_fw->ref = 1;

  479.     pmv_bw->ref = 0;

  480.     /* scale the co-located motion vector according to its temporal span */

  481.     pmv_fw->x =     (((den + (den * col_mv->x * pmv_fw->dist ^ m) - m - 1) >> 14) ^ m) - m;

  482.     pmv_bw->x = m - (((den + (den * col_mv->x * pmv_bw->dist ^ m) - m - 1) >> 14) ^ m);

  483.     m = col_mv->y >> 31;

  484.     pmv_fw->y =     (((den + (den * col_mv->y * pmv_fw->dist ^ m) - m - 1) >> 14) ^ m) - m;

  485.     pmv_bw->y = m - (((den + (den * col_mv->y * pmv_bw->dist ^ m) - m - 1) >> 14) ^ m);

  486. }

  487. 

  488. static inline void mv_pred_sym(AVSContext *h, cavs_vector *src,

  489.                                enum cavs_block size)

  490. {

  491.     cavs_vector *dst = src + MV_BWD_OFFS;

  492. 

  493.     /* backward mv is the scaled and negated forward mv */

  494.     dst->x = -((src->x * h->sym_factor + 256) >> 9);

  495.     dst->y = -((src->y * h->sym_factor + 256) >> 9);

  496.     dst->ref = 0;

  497.     dst->dist = h->dist[0];

  498.     set_mvs(dst, size);

  499. }

  500. 

  501. /*****************************************************************************

  502.  *

  503.  * residual data decoding

  504.  *

  505.  ****************************************************************************/

  506. 

  507. /** kth-order exponential golomb code */

  508. static inline int get_ue_code(GetBitContext *gb, int order)

  509. {

  510.     if (order) {

  511.         int ret = get_ue_golomb(gb) << order;

  512.         return ret + get_bits(gb, order);

  513.     }

  514.     return get_ue_golomb(gb);

  515. }

  516. 

  517. static inline int dequant(AVSContext *h, DCTELEM *level_buf, uint8_t *run_buf,

  518.                           DCTELEM *dst, int mul, int shift, int coeff_num)

  519. {

  520.     int round = 1 << (shift - 1);

  521.     int pos = -1;

  522.     const uint8_t *scantab = h->scantable.permutated;

  523. 

  524.     /* inverse scan and dequantization */

  525.     while (--coeff_num >= 0) {

  526.         pos += run_buf[coeff_num];

  527.         if (pos > 63) {

  528.             av_log(h->s.avctx, AV_LOG_ERROR,

  529.                    "position out of block bounds at pic %d MB(%d,%d)\n",

  530.                    h->picture.poc, h->mbx, h->mby);

  531.             return -1;

  532.         }

  533.         dst[scantab[pos]] = (level_buf[coeff_num] * mul + round) >> shift;

  534.     }

  535.     return 0;

  536. }

  537. 

  538. /**

  539.  * decode coefficients from one 8x8 block, dequantize, inverse transform

  540.  *  and add them to sample block

  541.  * @param r pointer to 2D VLC table

  542.  * @param esc_golomb_order escape codes are k-golomb with this order k

  543.  * @param qp quantizer

  544.  * @param dst location of sample block

  545.  * @param stride line stride in frame buffer

  546.  */

  547. static int decode_residual_block(AVSContext *h, GetBitContext *gb,

  548.                                  const struct dec_2dvlc *r, int esc_golomb_order,

  549.                                  int qp, uint8_t *dst, int stride)

  550. {

  551.     int i, level_code, esc_code, level, run, mask;

  552.     DCTELEM level_buf[65];

  553.     uint8_t run_buf[65];

  554.     DCTELEM *block = h->block;

  555. 

  556.     for (i = 0;i < 65; i++) {

  557.         level_code = get_ue_code(gb, r->golomb_order);

  558.         if (level_code >= ESCAPE_CODE) {

  559.             run      = ((level_code - ESCAPE_CODE) >> 1) + 1;

  560.             esc_code = get_ue_code(gb, esc_golomb_order);

  561.             level    = esc_code + (run > r->max_run ? 1 : r->level_add[run]);

  562.             while (level > r->inc_limit)

  563.                 r++;

  564.             mask  = -(level_code & 1);

  565.             level = (level ^ mask) - mask;

  566.         } else if (level_code >= 0) {

  567.             level = r->rltab[level_code][0];

  568.             if (!level) //end of block signal

  569.                 break;

  570.             run = r->rltab[level_code][1];

  571.             r  += r->rltab[level_code][2];

  572.         } else {

  573.             break;

  574.         }

  575.         level_buf[i] = level;

  576.         run_buf[i]   = run;

  577.     }

  578.     if (dequant(h, level_buf, run_buf, block, dequant_mul[qp],

  579.                 dequant_shift[qp], i))

  580.         return -1;

  581.     h->cdsp.cavs_idct8_add(dst, block, stride);

  582.     h->s.dsp.clear_block(block);

  583.     return 0;

  584. }

  585. 

  586. 

  587. static inline void decode_residual_chroma(AVSContext *h)

  588. {

  589.     if (h->cbp & (1 << 4))

  590.         decode_residual_block(h, &h->s.gb, chroma_dec, 0,

  591.                               cavs_chroma_qp[h->qp], h->cu, h->c_stride);

  592.     if (h->cbp & (1 << 5))

  593.         decode_residual_block(h, &h->s.gb, chroma_dec, 0,

  594.                               cavs_chroma_qp[h->qp], h->cv, h->c_stride);

  595. }

  596. 

  597. static inline int decode_residual_inter(AVSContext *h)

  598. {

  599.     int block;

  600. 

  601.     /* get coded block pattern */

  602.     int cbp = get_ue_golomb(&h->s.gb);

  603.     if (cbp > 63) {

  604.         av_log(h->s.avctx, AV_LOG_ERROR, "illegal inter cbp\n");

  605.         return -1;

  606.     }

  607.     h->cbp = cbp_tab[cbp][1];

  608. 

  609.     /* get quantizer */

  610.     if (h->cbp && !h->qp_fixed)

  611.         h->qp = (h->qp + get_se_golomb(&h->s.gb)) & 63;

  612.     for (block = 0; block < 4; block++)

  613.         if (h->cbp & (1 << block))

  614.             decode_residual_block(h, &h->s.gb, inter_dec, 0, h->qp,

  615.                                   h->cy + h->luma_scan[block], h->l_stride);

  616.     decode_residual_chroma(h);

  617. 

  618.     return 0;

  619. }

  620. 

  621. /*****************************************************************************

  622.  *

  623.  * macroblock level

  624.  *

  625.  ****************************************************************************/

  626. 

  627. static inline void set_mv_intra(AVSContext *h)

  628. {

  629.     h->mv[MV_FWD_X0] = ff_cavs_intra_mv;

  630.     set_mvs(&h->mv[MV_FWD_X0], BLK_16X16);

  631.     h->mv[MV_BWD_X0] = ff_cavs_intra_mv;

  632.     set_mvs(&h->mv[MV_BWD_X0], BLK_16X16);

  633.     if (h->pic_type != AV_PICTURE_TYPE_B)

  634.         h->col_type_base[h->mbidx] = I_8X8;

  635. }

  636. 

  637. static int decode_mb_i(AVSContext *h, int cbp_code)

  638. {

  639.     GetBitContext *gb = &h->s.gb;

  640.     unsigned pred_mode_uv;

  641.     int block;

  642.     uint8_t top[18];

  643.     uint8_t *left = NULL;

  644.     uint8_t *d;

  645. 

  646.     ff_cavs_init_mb(h);

  647. 

  648.     /* get intra prediction modes from stream */

  649.     for (block = 0; block < 4; block++) {

  650.         int nA, nB, predpred;

  651.         int pos = scan3x3[block];

  652. 

  653.         nA = h->pred_mode_Y[pos - 1];

  654.         nB = h->pred_mode_Y[pos - 3];

  655.         predpred = FFMIN(nA, nB);

  656.         if (predpred == NOT_AVAIL) // if either is not available

  657.             predpred = INTRA_L_LP;

  658.         if (!get_bits1(gb)) {

  659.             int rem_mode = get_bits(gb, 2);

  660.             predpred     = rem_mode + (rem_mode >= predpred);

  661.         }

  662.         h->pred_mode_Y[pos] = predpred;

  663.     }

  664.     pred_mode_uv = get_ue_golomb(gb);

  665.     if (pred_mode_uv > 6) {

  666.         av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra chroma pred mode\n");

  667.         return -1;

  668.     }

  669.     ff_cavs_modify_mb_i(h, &pred_mode_uv);

  670. 

  671.     /* get coded block pattern */

  672.     if (h->pic_type == AV_PICTURE_TYPE_I)

  673.         cbp_code = get_ue_golomb(gb);

  674.     if (cbp_code > 63) {

  675.         av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra cbp\n");

  676.         return -1;

  677.     }

  678.     h->cbp = cbp_tab[cbp_code][0];

  679.     if (h->cbp && !h->qp_fixed)

  680.         h->qp = (h->qp + get_se_golomb(gb)) & 63; //qp_delta

  681. 

  682.     /* luma intra prediction interleaved with residual decode/transform/add */

  683.     for (block = 0; block < 4; block++) {

  684.         d = h->cy + h->luma_scan[block];

  685.         ff_cavs_load_intra_pred_luma(h, top, &left, block);

  686.         h->intra_pred_l[h->pred_mode_Y[scan3x3[block]]]

  687.             (d, top, left, h->l_stride);

  688.         if (h->cbp & (1<<block))

  689.             decode_residual_block(h, gb, intra_dec, 1, h->qp, d, h->l_stride);

  690.     }

  691. 

  692.     /* chroma intra prediction */

  693.     ff_cavs_load_intra_pred_chroma(h);

  694.     h->intra_pred_c[pred_mode_uv](h->cu, &h->top_border_u[h->mbx * 10],

  695.                                   h->left_border_u, h->c_stride);

  696.     h->intra_pred_c[pred_mode_uv](h->cv, &h->top_border_v[h->mbx * 10],

  697.                                   h->left_border_v, h->c_stride);

  698. 

  699.     decode_residual_chroma(h);

  700.     ff_cavs_filter(h, I_8X8);

  701.     set_mv_intra(h);

  702.     return 0;

  703. }

  704. 

  705. static inline void set_intra_mode_default(AVSContext *h)

  706. {

  707.     if (h->stream_revision > 0) {

  708.         h->pred_mode_Y[3] =  h->pred_mode_Y[6] = NOT_AVAIL;

  709.         h->top_pred_Y[h->mbx * 2 + 0] = h->top_pred_Y[h->mbx * 2 + 1] = NOT_AVAIL;

  710.     } else {

  711.         h->pred_mode_Y[3] =  h->pred_mode_Y[6] = INTRA_L_LP;

  712.         h->top_pred_Y[h->mbx * 2 + 0] = h->top_pred_Y[h->mbx * 2 + 1] = INTRA_L_LP;

  713.     }

  714. }

  715. 

  716. static void decode_mb_p(AVSContext *h, enum cavs_mb mb_type)

  717. {

  718.     GetBitContext *gb = &h->s.gb;

  719.     int ref[4];

  720. 

  721.     ff_cavs_init_mb(h);

  722.     switch (mb_type) {

  723.     case P_SKIP:

  724.         ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_PSKIP,  BLK_16X16, 0);

  725.         break;

  726.     case P_16X16:

  727.         ref[0] = h->ref_flag ? 0 : get_bits1(gb);

  728.         ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, ref[0]);

  729.         break;

  730.     case P_16X8:

  731.         ref[0] = h->ref_flag ? 0 : get_bits1(gb);

  732.         ref[2] = h->ref_flag ? 0 : get_bits1(gb);

  733.         ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP,    BLK_16X8, ref[0]);

  734.         ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT,   BLK_16X8, ref[2]);

  735.         break;

  736.     case P_8X16:

  737.         ref[0] = h->ref_flag ? 0 : get_bits1(gb);

  738.         ref[1] = h->ref_flag ? 0 : get_bits1(gb);

  739.         ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT,     BLK_8X16, ref[0]);

  740.         ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_TOPRIGHT, BLK_8X16, ref[1]);

  741.         break;

  742.     case P_8X8:

  743.         ref[0] = h->ref_flag ? 0 : get_bits1(gb);

  744.         ref[1] = h->ref_flag ? 0 : get_bits1(gb);

  745.         ref[2] = h->ref_flag ? 0 : get_bits1(gb);

  746.         ref[3] = h->ref_flag ? 0 : get_bits1(gb);

  747.         ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_MEDIAN,   BLK_8X8, ref[0]);

  748.         ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_MEDIAN,   BLK_8X8, ref[1]);

  749.         ff_cavs_mv(h, MV_FWD_X2, MV_FWD_X1, MV_PRED_MEDIAN,   BLK_8X8, ref[2]);

  750.         ff_cavs_mv(h, MV_FWD_X3, MV_FWD_X0, MV_PRED_MEDIAN,   BLK_8X8, ref[3]);

  751.     }

  752.     ff_cavs_inter(h, mb_type);

  753.     set_intra_mode_default(h);

  754.     store_mvs(h);

  755.     if (mb_type != P_SKIP)

  756.         decode_residual_inter(h);

  757.     ff_cavs_filter(h, mb_type);

  758.     h->col_type_base[h->mbidx] = mb_type;

  759. }

  760. 

  761. static void decode_mb_b(AVSContext *h, enum cavs_mb mb_type)

  762. {

  763.     int block;

  764.     enum cavs_sub_mb sub_type[4];

  765.     int flags;

  766. 

  767.     ff_cavs_init_mb(h);

  768. 

  769.     /* reset all MVs */

  770.     h->mv[MV_FWD_X0] = ff_cavs_dir_mv;

  771.     set_mvs(&h->mv[MV_FWD_X0], BLK_16X16);

  772.     h->mv[MV_BWD_X0] = ff_cavs_dir_mv;

  773.     set_mvs(&h->mv[MV_BWD_X0], BLK_16X16);

  774.     switch (mb_type) {

  775.     case B_SKIP:

  776.     case B_DIRECT:

  777.         if (!h->col_type_base[h->mbidx]) {

  778.             /* intra MB at co-location, do in-plane prediction */

  779.             ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_BSKIP, BLK_16X16, 1);

  780.             ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_BSKIP, BLK_16X16, 0);

  781.         } else

  782.             /* direct prediction from co-located P MB, block-wise */

  783.             for (block = 0; block < 4; block++)

  784.                 mv_pred_direct(h, &h->mv[mv_scan[block]],

  785.                                &h->col_mv[h->mbidx * 4 + block]);

  786.         break;

  787.     case B_FWD_16X16:

  788.         ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1);

  789.         break;

  790.     case B_SYM_16X16:

  791.         ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1);

  792.         mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X16);

  793.         break;

  794.     case B_BWD_16X16:

  795.         ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_MEDIAN, BLK_16X16, 0);

  796.         break;

  797.     case B_8X8:

  798.         for (block = 0; block < 4; block++)

  799.             sub_type[block] = get_bits(&h->s.gb, 2);

  800.         for (block = 0; block < 4; block++) {

  801.             switch (sub_type[block]) {

  802.             case B_SUB_DIRECT:

  803.                 if (!h->col_type_base[h->mbidx]) {

  804.                     /* intra MB at co-location, do in-plane prediction */

  805.                     ff_cavs_mv(h, mv_scan[block], mv_scan[block] - 3,

  806.                                MV_PRED_BSKIP, BLK_8X8, 1);

  807.                     ff_cavs_mv(h, mv_scan[block] + MV_BWD_OFFS,

  808.                                mv_scan[block] - 3 + MV_BWD_OFFS,

  809.                                MV_PRED_BSKIP, BLK_8X8, 0);

  810.                 } else

  811.                     mv_pred_direct(h, &h->mv[mv_scan[block]],

  812.                                    &h->col_mv[h->mbidx * 4 + block]);

  813.                 break;

  814.             case B_SUB_FWD:

  815.                 ff_cavs_mv(h, mv_scan[block], mv_scan[block] - 3,

  816.                            MV_PRED_MEDIAN, BLK_8X8, 1);

  817.                 break;

  818.             case B_SUB_SYM:

  819.                 ff_cavs_mv(h, mv_scan[block], mv_scan[block] - 3,

  820.                            MV_PRED_MEDIAN, BLK_8X8, 1);

  821.                 mv_pred_sym(h, &h->mv[mv_scan[block]], BLK_8X8);

  822.                 break;

  823.             }

  824.         }

  825.         for (block = 0; block < 4; block++) {

  826.             if (sub_type[block] == B_SUB_BWD)

  827.                 ff_cavs_mv(h, mv_scan[block] + MV_BWD_OFFS,

  828.                            mv_scan[block] + MV_BWD_OFFS - 3,

  829.                            MV_PRED_MEDIAN, BLK_8X8, 0);

  830.         }

  831.         break;

  832.     default:

  833.         assert((mb_type > B_SYM_16X16) && (mb_type < B_8X8));

  834.         flags = ff_cavs_partition_flags[mb_type];

  835.         if (mb_type & 1) { /* 16x8 macroblock types */

  836.             if (flags & FWD0)

  837.                 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP,  BLK_16X8, 1);

  838.             if (flags & SYM0)

  839.                 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X8);

  840.             if (flags & FWD1)

  841.                 ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT, BLK_16X8, 1);

  842.             if (flags & SYM1)

  843.                 mv_pred_sym(h, &h->mv[MV_FWD_X2], BLK_16X8);

  844.             if (flags & BWD0)

  845.                 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_TOP,  BLK_16X8, 0);

  846.             if (flags & BWD1)

  847.                 ff_cavs_mv(h, MV_BWD_X2, MV_BWD_A1, MV_PRED_LEFT, BLK_16X8, 0);

  848.         } else {          /* 8x16 macroblock types */

  849.             if (flags & FWD0)

  850.                 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT, BLK_8X16, 1);

  851.             if (flags & SYM0)

  852.                 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_8X16);

  853.             if (flags & FWD1)

  854.                 ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_TOPRIGHT, BLK_8X16, 1);

  855.             if (flags & SYM1)

  856.                 mv_pred_sym(h, &h->mv[MV_FWD_X1], BLK_8X16);

  857.             if (flags & BWD0)

  858.                 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_B3, MV_PRED_LEFT, BLK_8X16, 0);

  859.             if (flags & BWD1)

  860.                 ff_cavs_mv(h, MV_BWD_X1, MV_BWD_C2, MV_PRED_TOPRIGHT, BLK_8X16, 0);

  861.         }

  862.     }

  863.     ff_cavs_inter(h, mb_type);

  864.     set_intra_mode_default(h);

  865.     if (mb_type != B_SKIP)

  866.         decode_residual_inter(h);

  867.     ff_cavs_filter(h, mb_type);

  868. }

  869. 

  870. /*****************************************************************************

  871.  *

  872.  * slice level

  873.  *

  874.  ****************************************************************************/

  875. 

  876. static inline int decode_slice_header(AVSContext *h, GetBitContext *gb)

  877. {

  878.     if (h->stc > 0xAF)

  879.         av_log(h->s.avctx, AV_LOG_ERROR, "unexpected start code 0x%02x\n", h->stc);

  880.     h->mby   = h->stc;

  881.     h->mbidx = h->mby * h->mb_width;

  882. 

  883.     /* mark top macroblocks as unavailable */

  884.     h->flags &= ~(B_AVAIL | C_AVAIL);

  885.     if ((h->mby == 0) && (!h->qp_fixed)) {

  886.         h->qp_fixed = get_bits1(gb);

  887.         h->qp       = get_bits(gb, 6);

  888.     }

  889.     /* inter frame or second slice can have weighting params */

  890.     if ((h->pic_type != AV_PICTURE_TYPE_I) ||

  891.         (!h->pic_structure && h->mby >= h->mb_width / 2))

  892.         if (get_bits1(gb)) { //slice_weighting_flag

  893.             av_log(h->s.avctx, AV_LOG_ERROR,

  894.                    "weighted prediction not yet supported\n");

  895.         }

  896.     return 0;

  897. }

  898. 

  899. static inline int check_for_slice(AVSContext *h)

  900. {

  901.     GetBitContext *gb = &h->s.gb;

  902.     int align;

  903. 

  904.     if (h->mbx)

  905.         return 0;

  906.     align = (-get_bits_count(gb)) & 7;

  907.     /* check for stuffing byte */

  908.     if (!align && (show_bits(gb, 8) == 0x80))

  909.         align = 8;

  910.     if ((show_bits_long(gb, 24 + align) & 0xFFFFFF) == 0x000001) {

  911.         skip_bits_long(gb, 24 + align);

  912.         h->stc = get_bits(gb, 8);

  913.         if (h->stc >= h->mb_height)

  914.             return 0;

  915.         decode_slice_header(h, gb);

  916.         return 1;

  917.     }

  918.     return 0;

  919. }

  920. 

  921. /*****************************************************************************

  922.  *

  923.  * frame level

  924.  *

  925.  ****************************************************************************/

  926. 

  927. static int decode_pic(AVSContext *h)

  928. {

  929.     MpegEncContext *s = &h->s;

  930.     int skip_count    = -1;

  931.     enum cavs_mb mb_type;

  932. 

  933.     if (!s->context_initialized) {

  934.         if (ff_MPV_common_init(s) < 0)

  935.             return -1;

  936.         ff_init_scantable_permutation(s->dsp.idct_permutation,

  937.                                       h->cdsp.idct_perm);

  938.         ff_init_scantable(s->dsp.idct_permutation, &h->scantable, ff_zigzag_direct);

  939.     }

  940.     skip_bits(&s->gb, 16);//bbv_dwlay

  941.     if (h->stc == PIC_PB_START_CODE) {

  942.         h->pic_type = get_bits(&s->gb, 2) + AV_PICTURE_TYPE_I;

  943.         if (h->pic_type > AV_PICTURE_TYPE_B) {

  944.             av_log(s->avctx, AV_LOG_ERROR, "illegal picture type\n");

  945.             return -1;

  946.         }

  947.         /* make sure we have the reference frames we need */

  948.         if (!h->DPB[0].f.data[0] ||

  949.            (!h->DPB[1].f.data[0] && h->pic_type == AV_PICTURE_TYPE_B))

  950.             return -1;

  951.     } else {

  952.         h->pic_type = AV_PICTURE_TYPE_I;

  953.         if (get_bits1(&s->gb))

  954.             skip_bits(&s->gb, 24);//time_code

  955.         /* old sample clips were all progressive and no low_delay,

  956.            bump stream revision if detected otherwise */

  957.         if (s->low_delay || !(show_bits(&s->gb, 9) & 1))

  958.             h->stream_revision = 1;

  959.         /* similarly test top_field_first and repeat_first_field */

  960.         else if (show_bits(&s->gb, 11) & 3)

  961.             h->stream_revision = 1;

  962.         if (h->stream_revision > 0)

  963.             skip_bits(&s->gb, 1); //marker_bit

  964.     }

  965.     /* release last B frame */

  966.     if (h->picture.f.data[0])

  967.         s->avctx->release_buffer(s->avctx, &h->picture.f);

  968. 

  969.     ff_get_buffer(s->avctx, &h->picture.f);

  970.     ff_cavs_init_pic(h);

  971.     h->picture.poc = get_bits(&s->gb, 8) * 2;

  972. 

  973.     /* get temporal distances and MV scaling factors */

  974.     if (h->pic_type != AV_PICTURE_TYPE_B) {

  975.         h->dist[0] = (h->picture.poc - h->DPB[0].poc  + 512) % 512;

  976.     } else {

  977.         h->dist[0] = (h->DPB[0].poc  - h->picture.poc + 512) % 512;

  978.     }

  979.     h->dist[1] = (h->picture.poc - h->DPB[1].poc  + 512) % 512;

  980.     h->scale_den[0] = h->dist[0] ? 512/h->dist[0] : 0;

  981.     h->scale_den[1] = h->dist[1] ? 512/h->dist[1] : 0;

  982.     if (h->pic_type == AV_PICTURE_TYPE_B) {

  983.         h->sym_factor = h->dist[0] * h->scale_den[1];

  984.     } else {

  985.         h->direct_den[0] = h->dist[0] ? 16384 / h->dist[0] : 0;

  986.         h->direct_den[1] = h->dist[1] ? 16384 / h->dist[1] : 0;

  987.     }

  988. 

  989.     if (s->low_delay)

  990.         get_ue_golomb(&s->gb); //bbv_check_times

  991.     h->progressive   = get_bits1(&s->gb);

  992.     h->pic_structure = 1;

  993.     if (!h->progressive)

  994.         h->pic_structure = get_bits1(&s->gb);

  995.     if (!h->pic_structure && h->stc == PIC_PB_START_CODE)

  996.         skip_bits1(&s->gb);     //advanced_pred_mode_disable

  997.     skip_bits1(&s->gb);        //top_field_first

  998.     skip_bits1(&s->gb);        //repeat_first_field

  999.     h->qp_fixed = get_bits1(&s->gb);

  1000.     h->qp       = get_bits(&s->gb, 6);

  1001.     if (h->pic_type == AV_PICTURE_TYPE_I) {

  1002.         if (!h->progressive && !h->pic_structure)

  1003.             skip_bits1(&s->gb);//what is this?

  1004.         skip_bits(&s->gb, 4);   //reserved bits

  1005.     } else {

  1006.         if (!(h->pic_type == AV_PICTURE_TYPE_B && h->pic_structure == 1))

  1007.             h->ref_flag        = get_bits1(&s->gb);

  1008.         skip_bits(&s->gb, 4);   //reserved bits

  1009.         h->skip_mode_flag      = get_bits1(&s->gb);

  1010.     }

  1011.     h->loop_filter_disable     = get_bits1(&s->gb);

  1012.     if (!h->loop_filter_disable && get_bits1(&s->gb)) {

  1013.         h->alpha_offset        = get_se_golomb(&s->gb);

  1014.         h->beta_offset         = get_se_golomb(&s->gb);

  1015.     } else {

  1016.         h->alpha_offset = h->beta_offset  = 0;

  1017.     }

  1018.     if (h->pic_type == AV_PICTURE_TYPE_I) {

  1019.         do {

  1020.             check_for_slice(h);

  1021.             decode_mb_i(h, 0);

  1022.         } while (ff_cavs_next_mb(h));

  1023.     } else if (h->pic_type == AV_PICTURE_TYPE_P) {

  1024.         do {

  1025.             if (check_for_slice(h))

  1026.                 skip_count = -1;

  1027.             if (h->skip_mode_flag && (skip_count < 0))

  1028.                 skip_count = get_ue_golomb(&s->gb);

  1029.             if (h->skip_mode_flag && skip_count--) {

  1030.                 decode_mb_p(h, P_SKIP);

  1031.             } else {

  1032.                 mb_type = get_ue_golomb(&s->gb) + P_SKIP + h->skip_mode_flag;

  1033.                 if (mb_type > P_8X8)

  1034.                     decode_mb_i(h, mb_type - P_8X8 - 1);

  1035.                 else

  1036.                     decode_mb_p(h, mb_type);

  1037.             }

  1038.         } while (ff_cavs_next_mb(h));

  1039.     } else { /* AV_PICTURE_TYPE_B */

  1040.         do {

  1041.             if (check_for_slice(h))

  1042.                 skip_count = -1;

  1043.             if (h->skip_mode_flag && (skip_count < 0))

  1044.                 skip_count = get_ue_golomb(&s->gb);

  1045.             if (h->skip_mode_flag && skip_count--) {

  1046.                 decode_mb_b(h, B_SKIP);

  1047.             } else {

  1048.                 mb_type = get_ue_golomb(&s->gb) + B_SKIP + h->skip_mode_flag;

  1049.                 if (mb_type > B_8X8)

  1050.                     decode_mb_i(h, mb_type - B_8X8 - 1);

  1051.                 else

  1052.                     decode_mb_b(h, mb_type);

  1053.             }

  1054.         } while (ff_cavs_next_mb(h));

  1055.     }

  1056.     if (h->pic_type != AV_PICTURE_TYPE_B) {

  1057.         if (h->DPB[1].f.data[0])

  1058.             s->avctx->release_buffer(s->avctx, &h->DPB[1].f);

  1059.         h->DPB[1] = h->DPB[0];

  1060.         h->DPB[0] = h->picture;

  1061.         memset(&h->picture, 0, sizeof(Picture));

  1062.     }

  1063.     return 0;

  1064. }

  1065. 

  1066. /*****************************************************************************

  1067.  *

  1068.  * headers and interface

  1069.  *

  1070.  ****************************************************************************/

  1071. 

  1072. static int decode_seq_header(AVSContext *h)

  1073. {

  1074.     MpegEncContext *s = &h->s;

  1075.     int frame_rate_code;

  1076.     int width, height;

  1077. 

  1078.     h->profile = get_bits(&s->gb, 8);

  1079.     h->level   = get_bits(&s->gb, 8);

  1080.     skip_bits1(&s->gb); //progressive sequence

  1081. 

  1082.     width  = get_bits(&s->gb, 14);

  1083.     height = get_bits(&s->gb, 14);

  1084.     if ((s->width || s->height) && (s->width != width || s->height != height)) {

  1085.         av_log_missing_feature(s, "Width/height changing in CAVS", 0);

  1086.         return AVERROR_PATCHWELCOME;

  1087.     }

  1088.     s->width  = width;

  1089.     s->height = height;

  1090. 

  1091.     skip_bits(&s->gb, 2); //chroma format

  1092.     skip_bits(&s->gb, 3); //sample_precision

  1093.     h->aspect_ratio = get_bits(&s->gb, 4);

  1094.     frame_rate_code = get_bits(&s->gb, 4);

  1095.     skip_bits(&s->gb, 18); //bit_rate_lower

  1096.     skip_bits1(&s->gb);    //marker_bit

  1097.     skip_bits(&s->gb, 12); //bit_rate_upper

  1098.     s->low_delay =  get_bits1(&s->gb);

  1099.     h->mb_width  = (s->width  + 15) >> 4;

  1100.     h->mb_height = (s->height + 15) >> 4;

  1101.     h->s.avctx->time_base.den = ff_mpeg12_frame_rate_tab[frame_rate_code].num;

  1102.     h->s.avctx->time_base.num = ff_mpeg12_frame_rate_tab[frame_rate_code].den;

  1103.     h->s.avctx->width  = s->width;

  1104.     h->s.avctx->height = s->height;

  1105.     if (!h->top_qp)

  1106.         ff_cavs_init_top_lines(h);

  1107.     return 0;

  1108. }

  1109. 

  1110. static void cavs_flush(AVCodecContext * avctx)

  1111. {

  1112.     AVSContext *h = avctx->priv_data;

  1113.     h->got_keyframe = 0;

  1114. }

  1115. 

  1116. static int cavs_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,

  1117.                              AVPacket *avpkt)

  1118. {

  1119.     AVSContext *h      = avctx->priv_data;

  1120.     MpegEncContext *s  = &h->s;

  1121.     const uint8_t *buf = avpkt->data;

  1122.     int buf_size       = avpkt->size;

  1123.     AVFrame *picture   = data;

  1124.     uint32_t stc       = -1;

  1125.     int input_size;

  1126.     const uint8_t *buf_end;

  1127.     const uint8_t *buf_ptr;

  1128. 

  1129.     s->avctx = avctx;

  1130. 

  1131.     if (buf_size == 0) {

  1132.         if (!s->low_delay && h->DPB[0].f.data[0]) {

  1133.             *got_frame = 1;

  1134.             *picture = h->DPB[0].f;

  1135.             memset(&h->DPB[0], 0, sizeof(h->DPB[0]));

  1136.         }

  1137.         return 0;

  1138.     }

  1139. 

  1140.     buf_ptr = buf;

  1141.     buf_end = buf + buf_size;

  1142.     for(;;) {

  1143.         buf_ptr = avpriv_mpv_find_start_code(buf_ptr, buf_end, &stc);

  1144.         if ((stc & 0xFFFFFE00) || buf_ptr == buf_end)

  1145.             return FFMAX(0, buf_ptr - buf - s->parse_context.last_index);

  1146.         input_size = (buf_end - buf_ptr) * 8;

  1147.         switch (stc) {

  1148.         case CAVS_START_CODE:

  1149.             init_get_bits(&s->gb, buf_ptr, input_size);

  1150.             decode_seq_header(h);

  1151.             break;

  1152.         case PIC_I_START_CODE:

  1153.             if (!h->got_keyframe) {

  1154.                 if(h->DPB[0].f.data[0])

  1155.                     avctx->release_buffer(avctx, &h->DPB[0].f);

  1156.                 if(h->DPB[1].f.data[0])

  1157.                     avctx->release_buffer(avctx, &h->DPB[1].f);

  1158.                 h->got_keyframe = 1;

  1159.             }

  1160.         case PIC_PB_START_CODE:

  1161.             *got_frame = 0;

  1162.             if (!h->got_keyframe)

  1163.                 break;

  1164.             init_get_bits(&s->gb, buf_ptr, input_size);

  1165.             h->stc = stc;

  1166.             if (decode_pic(h))

  1167.                 break;

  1168.             *got_frame = 1;

  1169.             if (h->pic_type != AV_PICTURE_TYPE_B) {

  1170.                 if (h->DPB[1].f.data[0]) {

  1171.                     *picture = h->DPB[1].f;

  1172.                 } else {

  1173.                     *got_frame = 0;

  1174.                 }

  1175.             } else

  1176.                 *picture = h->picture.f;

  1177.             break;

  1178.         case EXT_START_CODE:

  1179.             //mpeg_decode_extension(avctx, buf_ptr, input_size);

  1180.             break;

  1181.         case USER_START_CODE:

  1182.             //mpeg_decode_user_data(avctx, buf_ptr, input_size);

  1183.             break;

  1184.         default:

  1185.             if (stc <= SLICE_MAX_START_CODE) {

  1186.                 init_get_bits(&s->gb, buf_ptr, input_size);

  1187.                 decode_slice_header(h, &s->gb);

  1188.             }

  1189.             break;

  1190.         }

  1191.     }

  1192. }

  1193. 

  1194. AVCodec ff_cavs_decoder = {

  1195.     .name           = "cavs",

  1196.     .type           = AVMEDIA_TYPE_VIDEO,

  1197.     .id             = AV_CODEC_ID_CAVS,

  1198.     .priv_data_size = sizeof(AVSContext),

  1199.     .init           = ff_cavs_init,

  1200.     .close          = ff_cavs_end,

  1201.     .decode         = cavs_decode_frame,

  1202.     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY,

  1203.     .flush          = cavs_flush,

  1204.     .long_name      = NULL_IF_CONFIG_SMALL("Chinese AVS (Audio Video Standard) (AVS1-P2, JiZhun profile)"),

  1205. };