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FFmpeg/libavcodec/4xm.c

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  1. /*

  2.  * 4XM codec

  3.  * Copyright (c) 2003 Michael Niedermayer

  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.  * 4XM codec.

  25.  */

  26. 

  27. #include "libavutil/frame.h"

  28. #include "libavutil/intreadwrite.h"

  29. #include "avcodec.h"

  30. #include "bytestream.h"

  31. #include "dsputil.h"

  32. #include "get_bits.h"

  33. #include "internal.h"

  34. 

  35. //#undef NDEBUG

  36. //#include <assert.h>

  37. 

  38. #define BLOCK_TYPE_VLC_BITS 5

  39. #define ACDC_VLC_BITS 9

  40. 

  41. #define CFRAME_BUFFER_COUNT 100

  42. 

  43. static const uint8_t block_type_tab[2][4][8][2] = {

  44.     {

  45.         {    // { 8, 4, 2 } x { 8, 4, 2}

  46.             { 0, 1 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 30, 5 }, { 31, 5 }, { 0, 0 }

  47.         }, { // { 8, 4 } x 1

  48.             { 0, 1 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }

  49.         }, { // 1 x { 8, 4 }

  50.             { 0, 1 }, { 2, 2 }, { 0, 0 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }

  51.         }, { // 1 x 2, 2 x 1

  52.             { 0, 1 }, { 0, 0 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }

  53.         }

  54.     }, {

  55.         {   // { 8, 4, 2 } x { 8, 4, 2}

  56.             { 1, 2 }, { 4, 3 }, { 5, 3 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }

  57.         }, {// { 8, 4 } x 1

  58.             { 1, 2 }, { 0, 0 }, { 2, 2 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }

  59.         }, {// 1 x { 8, 4 }

  60.             { 1, 2 }, { 2, 2 }, { 0, 0 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }

  61.         }, {// 1 x 2, 2 x 1

  62.             { 1, 2 }, { 0, 0 }, { 0, 0 }, { 0, 2 }, { 2, 2 }, { 6, 3 }, { 7, 3 }

  63.       }

  64.     }

  65. };

  66. 

  67. static const uint8_t size2index[4][4] = {

  68.     { -1, 3, 1, 1 },

  69.     {  3, 0, 0, 0 },

  70.     {  2, 0, 0, 0 },

  71.     {  2, 0, 0, 0 },

  72. };

  73. 

  74. static const int8_t mv[256][2] = {

  75.     {   0,   0 }, {   0,  -1 }, {  -1,   0 }, {   1,   0 }, {   0,   1 }, {  -1,  -1 }, {   1,  -1 }, {  -1,   1 },

  76.     {   1,   1 }, {   0,  -2 }, {  -2,   0 }, {   2,   0 }, {   0,   2 }, {  -1,  -2 }, {   1,  -2 }, {  -2,  -1 },

  77.     {   2,  -1 }, {  -2,   1 }, {   2,   1 }, {  -1,   2 }, {   1,   2 }, {  -2,  -2 }, {   2,  -2 }, {  -2,   2 },

  78.     {   2,   2 }, {   0,  -3 }, {  -3,   0 }, {   3,   0 }, {   0,   3 }, {  -1,  -3 }, {   1,  -3 }, {  -3,  -1 },

  79.     {   3,  -1 }, {  -3,   1 }, {   3,   1 }, {  -1,   3 }, {   1,   3 }, {  -2,  -3 }, {   2,  -3 }, {  -3,  -2 },

  80.     {   3,  -2 }, {  -3,   2 }, {   3,   2 }, {  -2,   3 }, {   2,   3 }, {   0,  -4 }, {  -4,   0 }, {   4,   0 },

  81.     {   0,   4 }, {  -1,  -4 }, {   1,  -4 }, {  -4,  -1 }, {   4,  -1 }, {   4,   1 }, {  -1,   4 }, {   1,   4 },

  82.     {  -3,  -3 }, {  -3,   3 }, {   3,   3 }, {  -2,  -4 }, {  -4,  -2 }, {   4,  -2 }, {  -4,   2 }, {  -2,   4 },

  83.     {   2,   4 }, {  -3,  -4 }, {   3,  -4 }, {   4,  -3 }, {  -5,   0 }, {  -4,   3 }, {  -3,   4 }, {   3,   4 },

  84.     {  -1,  -5 }, {  -5,  -1 }, {  -5,   1 }, {  -1,   5 }, {  -2,  -5 }, {   2,  -5 }, {   5,  -2 }, {   5,   2 },

  85.     {  -4,  -4 }, {  -4,   4 }, {  -3,  -5 }, {  -5,  -3 }, {  -5,   3 }, {   3,   5 }, {  -6,   0 }, {   0,   6 },

  86.     {  -6,  -1 }, {  -6,   1 }, {   1,   6 }, {   2,  -6 }, {  -6,   2 }, {   2,   6 }, {  -5,  -4 }, {   5,   4 },

  87.     {   4,   5 }, {  -6,  -3 }, {   6,   3 }, {  -7,   0 }, {  -1,  -7 }, {   5,  -5 }, {  -7,   1 }, {  -1,   7 },

  88.     {   4,  -6 }, {   6,   4 }, {  -2,  -7 }, {  -7,   2 }, {  -3,  -7 }, {   7,  -3 }, {   3,   7 }, {   6,  -5 },

  89.     {   0,  -8 }, {  -1,  -8 }, {  -7,  -4 }, {  -8,   1 }, {   4,   7 }, {   2,  -8 }, {  -2,   8 }, {   6,   6 },

  90.     {  -8,   3 }, {   5,  -7 }, {  -5,   7 }, {   8,  -4 }, {   0,  -9 }, {  -9,  -1 }, {   1,   9 }, {   7,  -6 },

  91.     {  -7,   6 }, {  -5,  -8 }, {  -5,   8 }, {  -9,   3 }, {   9,  -4 }, {   7,  -7 }, {   8,  -6 }, {   6,   8 },

  92.     {  10,   1 }, { -10,   2 }, {   9,  -5 }, {  10,  -3 }, {  -8,  -7 }, { -10,  -4 }, {   6,  -9 }, { -11,   0 },

  93.     {  11,   1 }, { -11,  -2 }, {  -2,  11 }, {   7,  -9 }, {  -7,   9 }, {  10,   6 }, {  -4,  11 }, {   8,  -9 },

  94.     {   8,   9 }, {   5,  11 }, {   7, -10 }, {  12,  -3 }, {  11,   6 }, {  -9,  -9 }, {   8,  10 }, {   5,  12 },

  95.     { -11,   7 }, {  13,   2 }, {   6, -12 }, {  10,   9 }, { -11,   8 }, {  -7,  12 }, {   0,  14 }, {  14,  -2 },

  96.     {  -9,  11 }, {  -6,  13 }, { -14,  -4 }, {  -5, -14 }, {   5,  14 }, { -15,  -1 }, { -14,  -6 }, {   3, -15 },

  97.     {  11, -11 }, {  -7,  14 }, {  -5,  15 }, {   8, -14 }, {  15,   6 }, {   3,  16 }, {   7, -15 }, { -16,   5 },

  98.     {   0,  17 }, { -16,  -6 }, { -10,  14 }, { -16,   7 }, {  12,  13 }, { -16,   8 }, { -17,   6 }, { -18,   3 },

  99.     {  -7,  17 }, {  15,  11 }, {  16,  10 }, {   2, -19 }, {   3, -19 }, { -11, -16 }, { -18,   8 }, { -19,  -6 },

  100.     {   2, -20 }, { -17, -11 }, { -10, -18 }, {   8,  19 }, { -21,  -1 }, { -20,   7 }, {  -4,  21 }, {  21,   5 },

  101.     {  15,  16 }, {   2, -22 }, { -10, -20 }, { -22,   5 }, {  20, -11 }, {  -7, -22 }, { -12,  20 }, {  23,  -5 },

  102.     {  13, -20 }, {  24,  -2 }, { -15,  19 }, { -11,  22 }, {  16,  19 }, {  23, -10 }, { -18, -18 }, {  -9, -24 },

  103.     {  24, -10 }, {  -3,  26 }, { -23,  13 }, { -18, -20 }, {  17,  21 }, {  -4,  27 }, {  27,   6 }, {   1, -28 },

  104.     { -11,  26 }, { -17, -23 }, {   7,  28 }, {  11, -27 }, {  29,   5 }, { -23, -19 }, { -28, -11 }, { -21,  22 },

  105.     { -30,   7 }, { -17,  26 }, { -27,  16 }, {  13,  29 }, {  19, -26 }, {  10, -31 }, { -14, -30 }, {  20, -27 },

  106.     { -29,  18 }, { -16, -31 }, { -28, -22 }, {  21, -30 }, { -25,  28 }, {  26, -29 }, {  25, -32 }, { -32, -32 }

  107. };

  108. 

  109. /* This is simply the scaled down elementwise product of the standard JPEG

  110.  * quantizer table and the AAN premul table. */

  111. static const uint8_t dequant_table[64] = {

  112.     16, 15, 13, 19, 24, 31, 28, 17,

  113.     17, 23, 25, 31, 36, 63, 45, 21,

  114.     18, 24, 27, 37, 52, 59, 49, 20,

  115.     16, 28, 34, 40, 60, 80, 51, 20,

  116.     18, 31, 48, 66, 68, 86, 56, 21,

  117.     19, 38, 56, 59, 64, 64, 48, 20,

  118.     27, 48, 55, 55, 56, 51, 35, 15,

  119.     20, 35, 34, 32, 31, 22, 15,  8,

  120. };

  121. 

  122. static VLC block_type_vlc[2][4];

  123. 

  124. 

  125. typedef struct CFrameBuffer {

  126.     unsigned int allocated_size;

  127.     unsigned int size;

  128.     int id;

  129.     uint8_t *data;

  130. } CFrameBuffer;

  131. 

  132. typedef struct FourXContext {

  133.     AVCodecContext *avctx;

  134.     DSPContext dsp;

  135.     AVFrame *last_picture;

  136.     GetBitContext pre_gb;          ///< ac/dc prefix

  137.     GetBitContext gb;

  138.     GetByteContext g;

  139.     GetByteContext g2;

  140.     int mv[256];

  141.     VLC pre_vlc;

  142.     int last_dc;

  143.     DECLARE_ALIGNED(16, int16_t, block)[6][64];

  144.     void *bitstream_buffer;

  145.     unsigned int bitstream_buffer_size;

  146.     int version;

  147.     CFrameBuffer cfrm[CFRAME_BUFFER_COUNT];

  148. } FourXContext;

  149. 

  150. 

  151. #define FIX_1_082392200  70936

  152. #define FIX_1_414213562  92682

  153. #define FIX_1_847759065 121095

  154. #define FIX_2_613125930 171254

  155. 

  156. #define MULTIPLY(var, const) (((var) * (const)) >> 16)

  157. 

  158. static void idct(int16_t block[64])

  159. {

  160.     int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;

  161.     int tmp10, tmp11, tmp12, tmp13;

  162.     int z5, z10, z11, z12, z13;

  163.     int i;

  164.     int temp[64];

  165. 

  166.     for (i = 0; i < 8; i++) {

  167.         tmp10 = block[8 * 0 + i] + block[8 * 4 + i];

  168.         tmp11 = block[8 * 0 + i] - block[8 * 4 + i];

  169. 

  170.         tmp13 = block[8 * 2 + i] + block[8 * 6 + i];

  171.         tmp12 = MULTIPLY(block[8 * 2 + i] - block[8 * 6 + i], FIX_1_414213562) - tmp13;

  172. 

  173.         tmp0 = tmp10 + tmp13;

  174.         tmp3 = tmp10 - tmp13;

  175.         tmp1 = tmp11 + tmp12;

  176.         tmp2 = tmp11 - tmp12;

  177. 

  178.         z13 = block[8 * 5 + i] + block[8 * 3 + i];

  179.         z10 = block[8 * 5 + i] - block[8 * 3 + i];

  180.         z11 = block[8 * 1 + i] + block[8 * 7 + i];

  181.         z12 = block[8 * 1 + i] - block[8 * 7 + i];

  182. 

  183.         tmp7  =          z11 + z13;

  184.         tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);

  185. 

  186.         z5    = MULTIPLY(z10 + z12, FIX_1_847759065);

  187.         tmp10 = MULTIPLY(z12,  FIX_1_082392200) - z5;

  188.         tmp12 = MULTIPLY(z10, -FIX_2_613125930) + z5;

  189. 

  190.         tmp6 = tmp12 - tmp7;

  191.         tmp5 = tmp11 - tmp6;

  192.         tmp4 = tmp10 + tmp5;

  193. 

  194.         temp[8 * 0 + i] = tmp0 + tmp7;

  195.         temp[8 * 7 + i] = tmp0 - tmp7;

  196.         temp[8 * 1 + i] = tmp1 + tmp6;

  197.         temp[8 * 6 + i] = tmp1 - tmp6;

  198.         temp[8 * 2 + i] = tmp2 + tmp5;

  199.         temp[8 * 5 + i] = tmp2 - tmp5;

  200.         temp[8 * 4 + i] = tmp3 + tmp4;

  201.         temp[8 * 3 + i] = tmp3 - tmp4;

  202.     }

  203. 

  204.     for (i = 0; i < 8 * 8; i += 8) {

  205.         tmp10 = temp[0 + i] + temp[4 + i];

  206.         tmp11 = temp[0 + i] - temp[4 + i];

  207. 

  208.         tmp13 = temp[2 + i] + temp[6 + i];

  209.         tmp12 = MULTIPLY(temp[2 + i] - temp[6 + i], FIX_1_414213562) - tmp13;

  210. 

  211.         tmp0 = tmp10 + tmp13;

  212.         tmp3 = tmp10 - tmp13;

  213.         tmp1 = tmp11 + tmp12;

  214.         tmp2 = tmp11 - tmp12;

  215. 

  216.         z13 = temp[5 + i] + temp[3 + i];

  217.         z10 = temp[5 + i] - temp[3 + i];

  218.         z11 = temp[1 + i] + temp[7 + i];

  219.         z12 = temp[1 + i] - temp[7 + i];

  220. 

  221.         tmp7  = z11 + z13;

  222.         tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);

  223. 

  224.         z5    = MULTIPLY(z10 + z12, FIX_1_847759065);

  225.         tmp10 = MULTIPLY(z12,  FIX_1_082392200) - z5;

  226.         tmp12 = MULTIPLY(z10, -FIX_2_613125930) + z5;

  227. 

  228.         tmp6 = tmp12 - tmp7;

  229.         tmp5 = tmp11 - tmp6;

  230.         tmp4 = tmp10 + tmp5;

  231. 

  232.         block[0 + i] = (tmp0 + tmp7) >> 6;

  233.         block[7 + i] = (tmp0 - tmp7) >> 6;

  234.         block[1 + i] = (tmp1 + tmp6) >> 6;

  235.         block[6 + i] = (tmp1 - tmp6) >> 6;

  236.         block[2 + i] = (tmp2 + tmp5) >> 6;

  237.         block[5 + i] = (tmp2 - tmp5) >> 6;

  238.         block[4 + i] = (tmp3 + tmp4) >> 6;

  239.         block[3 + i] = (tmp3 - tmp4) >> 6;

  240.     }

  241. }

  242. 

  243. static av_cold void init_vlcs(FourXContext *f)

  244. {

  245.     static VLC_TYPE table[2][4][32][2];

  246.     int i, j;

  247. 

  248.     for (i = 0; i < 2; i++) {

  249.         for (j = 0; j < 4; j++) {

  250.             block_type_vlc[i][j].table           = table[i][j];

  251.             block_type_vlc[i][j].table_allocated = 32;

  252.             init_vlc(&block_type_vlc[i][j], BLOCK_TYPE_VLC_BITS, 7,

  253.                      &block_type_tab[i][j][0][1], 2, 1,

  254.                      &block_type_tab[i][j][0][0], 2, 1,

  255.                      INIT_VLC_USE_NEW_STATIC);

  256.         }

  257.     }

  258. }

  259. 

  260. static void init_mv(FourXContext *f, int linesize)

  261. {

  262.     int i;

  263. 

  264.     for (i = 0; i < 256; i++) {

  265.         if (f->version > 1)

  266.             f->mv[i] = mv[i][0] + mv[i][1] * linesize / 2;

  267.         else

  268.             f->mv[i] = (i & 15) - 8 + ((i >> 4) - 8) * linesize / 2;

  269.     }

  270. }

  271. 

  272. #if HAVE_BIGENDIAN

  273. #define LE_CENTRIC_MUL(dst, src, scale, dc)             \

  274.     {                                                   \

  275.         unsigned tmpval = AV_RN32(src);                 \

  276.         tmpval = (tmpval << 16) | (tmpval >> 16);       \

  277.         tmpval = tmpval * (scale) + (dc);               \

  278.         tmpval = (tmpval << 16) | (tmpval >> 16);       \

  279.         AV_WN32A(dst, tmpval);                          \

  280.     }

  281. #else

  282. #define LE_CENTRIC_MUL(dst, src, scale, dc)              \

  283.     {                                                    \

  284.         unsigned tmpval = AV_RN32(src) * (scale) + (dc); \

  285.         AV_WN32A(dst, tmpval);                           \

  286.     }

  287. #endif

  288. 

  289. static inline void mcdc(uint16_t *dst, uint16_t *src, int log2w,

  290.                         int h, int stride, int scale, unsigned dc)

  291. {

  292.     int i;

  293.     dc *= 0x10001;

  294. 

  295.     switch (log2w) {

  296.     case 0:

  297.         for (i = 0; i < h; i++) {

  298.             dst[0] = scale * src[0] + dc;

  299.             if (scale)

  300.                 src += stride;

  301.             dst += stride;

  302.         }

  303.         break;

  304.     case 1:

  305.         for (i = 0; i < h; i++) {

  306.             LE_CENTRIC_MUL(dst, src, scale, dc);

  307.             if (scale)

  308.                 src += stride;

  309.             dst += stride;

  310.         }

  311.         break;

  312.     case 2:

  313.         for (i = 0; i < h; i++) {

  314.             LE_CENTRIC_MUL(dst, src, scale, dc);

  315.             LE_CENTRIC_MUL(dst + 2, src + 2, scale, dc);

  316.             if (scale)

  317.                 src += stride;

  318.             dst += stride;

  319.         }

  320.         break;

  321.     case 3:

  322.         for (i = 0; i < h; i++) {

  323.             LE_CENTRIC_MUL(dst,     src,     scale, dc);

  324.             LE_CENTRIC_MUL(dst + 2, src + 2, scale, dc);

  325.             LE_CENTRIC_MUL(dst + 4, src + 4, scale, dc);

  326.             LE_CENTRIC_MUL(dst + 6, src + 6, scale, dc);

  327.             if (scale)

  328.                 src += stride;

  329.             dst += stride;

  330.         }

  331.         break;

  332.     default:

  333.         assert(0);

  334.     }

  335. }

  336. 

  337. static void decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src,

  338.                            int log2w, int log2h, int stride)

  339. {

  340.     const int index = size2index[log2h][log2w];

  341.     const int h     = 1 << log2h;

  342.     int code        = get_vlc2(&f->gb,

  343.                                block_type_vlc[1 - (f->version > 1)][index].table,

  344.                                BLOCK_TYPE_VLC_BITS, 1);

  345.     uint16_t *start = (uint16_t *)f->last_picture->data[0];

  346.     uint16_t *end   = start + stride * (f->avctx->height - h + 1) - (1 << log2w);

  347. 

  348.     assert(code >= 0 && code <= 6);

  349. 

  350.     if (code == 0) {

  351.         src += f->mv[bytestream2_get_byte(&f->g)];

  352.         if (start > src || src > end) {

  353.             av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");

  354.             return;

  355.         }

  356.         mcdc(dst, src, log2w, h, stride, 1, 0);

  357.     } else if (code == 1) {

  358.         log2h--;

  359.         decode_p_block(f, dst, src, log2w, log2h, stride);

  360.         decode_p_block(f, dst + (stride << log2h),

  361.                           src + (stride << log2h), log2w, log2h, stride);

  362.     } else if (code == 2) {

  363.         log2w--;

  364.         decode_p_block(f, dst , src, log2w, log2h, stride);

  365.         decode_p_block(f, dst + (1 << log2w),

  366.                           src + (1 << log2w), log2w, log2h, stride);

  367.     } else if (code == 3 && f->version < 2) {

  368.         mcdc(dst, src, log2w, h, stride, 1, 0);

  369.     } else if (code == 4) {

  370.         src += f->mv[bytestream2_get_byte(&f->g)];

  371.         if (start > src || src > end) {

  372.             av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");

  373.             return;

  374.         }

  375.         mcdc(dst, src, log2w, h, stride, 1, bytestream2_get_le16(&f->g2));

  376.     } else if (code == 5) {

  377.         mcdc(dst, src, log2w, h, stride, 0, bytestream2_get_le16(&f->g2));

  378.     } else if (code == 6) {

  379.         if (log2w) {

  380.             dst[0]      = bytestream2_get_le16(&f->g2);

  381.             dst[1]      = bytestream2_get_le16(&f->g2);

  382.         } else {

  383.             dst[0]      = bytestream2_get_le16(&f->g2);

  384.             dst[stride] = bytestream2_get_le16(&f->g2);

  385.         }

  386.     }

  387. }

  388. 

  389. static int decode_p_frame(FourXContext *f, AVFrame *frame,

  390.                           const uint8_t *buf, int length)

  391. {

  392.     int x, y;

  393.     const int width  = f->avctx->width;

  394.     const int height = f->avctx->height;

  395.     uint16_t *src    = (uint16_t *)f->last_picture->data[0];

  396.     uint16_t *dst    = (uint16_t *)frame->data[0];

  397.     const int stride =             frame->linesize[0] >> 1;

  398.     unsigned int bitstream_size, bytestream_size, wordstream_size, extra,

  399.                  bytestream_offset, wordstream_offset;

  400. 

  401.     if (f->version > 1) {

  402.         extra           = 20;

  403.         bitstream_size  = AV_RL32(buf + 8);

  404.         wordstream_size = AV_RL32(buf + 12);

  405.         bytestream_size = AV_RL32(buf + 16);

  406.     } else {

  407.         extra           = 0;

  408.         bitstream_size  = AV_RL16(buf - 4);

  409.         wordstream_size = AV_RL16(buf - 2);

  410.         bytestream_size = FFMAX(length - bitstream_size - wordstream_size, 0);

  411.     }

  412. 

  413.     if (bitstream_size + bytestream_size + wordstream_size + extra != length

  414.         || bitstream_size  > (1 << 26)

  415.         || bytestream_size > (1 << 26)

  416.         || wordstream_size > (1 << 26)) {

  417.         av_log(f->avctx, AV_LOG_ERROR, "lengths %d %d %d %d\n",

  418.                bitstream_size, bytestream_size, wordstream_size,

  419.                bitstream_size + bytestream_size + wordstream_size - length);

  420.         return AVERROR_INVALIDDATA;

  421.     }

  422. 

  423.     av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,

  424.                    bitstream_size + FF_INPUT_BUFFER_PADDING_SIZE);

  425.     if (!f->bitstream_buffer)

  426.         return AVERROR(ENOMEM);

  427.     f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)(buf + extra),

  428.                      bitstream_size / 4);

  429.     memset((uint8_t*)f->bitstream_buffer + bitstream_size,

  430.            0, FF_INPUT_BUFFER_PADDING_SIZE);

  431.     init_get_bits(&f->gb, f->bitstream_buffer, 8 * bitstream_size);

  432. 

  433.     wordstream_offset = extra + bitstream_size;

  434.     bytestream_offset = extra + bitstream_size + wordstream_size;

  435.     bytestream2_init(&f->g2, buf + wordstream_offset,

  436.                      length - wordstream_offset);

  437.     bytestream2_init(&f->g, buf + bytestream_offset,

  438.                      length - bytestream_offset);

  439. 

  440.     init_mv(f, frame->linesize[0]);

  441. 

  442.     for (y = 0; y < height; y += 8) {

  443.         for (x = 0; x < width; x += 8)

  444.             decode_p_block(f, dst + x, src + x, 3, 3, stride);

  445.         src += 8 * stride;

  446.         dst += 8 * stride;

  447.     }

  448. 

  449.     return 0;

  450. }

  451. 

  452. /**

  453.  * decode block and dequantize.

  454.  * Note this is almost identical to MJPEG.

  455.  */

  456. static int decode_i_block(FourXContext *f, int16_t *block)

  457. {

  458.     int code, i, j, level, val;

  459. 

  460.     /* DC coef */

  461.     val = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);

  462.     if (val >> 4)

  463.         av_log(f->avctx, AV_LOG_ERROR, "error dc run != 0\n");

  464. 

  465.     if (val)

  466.         val = get_xbits(&f->gb, val);

  467. 

  468.     val        = val * dequant_table[0] + f->last_dc;

  469.     f->last_dc = block[0] = val;

  470.     /* AC coefs */

  471.     i = 1;

  472.     for (;;) {

  473.         code = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);

  474. 

  475.         /* EOB */

  476.         if (code == 0)

  477.             break;

  478.         if (code == 0xf0) {

  479.             i += 16;

  480.         } else {

  481.             level = get_xbits(&f->gb, code & 0xf);

  482.             i    += code >> 4;

  483.             if (i >= 64) {

  484.                 av_log(f->avctx, AV_LOG_ERROR, "run %d oveflow\n", i);

  485.                 return 0;

  486.             }

  487. 

  488.             j = ff_zigzag_direct[i];

  489.             block[j] = level * dequant_table[j];

  490.             i++;

  491.             if (i >= 64)

  492.                 break;

  493.         }

  494.     }

  495. 

  496.     return 0;

  497. }

  498. 

  499. static inline void idct_put(FourXContext *f, AVFrame *frame, int x, int y)

  500. {

  501.     int16_t (*block)[64] = f->block;

  502.     int stride           = frame->linesize[0] >> 1;

  503.     int i;

  504.     uint16_t *dst = ((uint16_t*)frame->data[0]) + y * stride + x;

  505. 

  506.     for (i = 0; i < 4; i++) {

  507.         block[i][0] += 0x80 * 8 * 8;

  508.         idct(block[i]);

  509.     }

  510. 

  511.     if (!(f->avctx->flags & CODEC_FLAG_GRAY)) {

  512.         for (i = 4; i < 6; i++)

  513.             idct(block[i]);

  514.     }

  515. 

  516.     /* Note transform is:

  517.      * y  = ( 1b + 4g + 2r) / 14

  518.      * cb = ( 3b - 2g - 1r) / 14

  519.      * cr = (-1b - 4g + 5r) / 14 */

  520.     for (y = 0; y < 8; y++) {

  521.         for (x = 0; x < 8; x++) {

  522.             int16_t *temp = block[(x >> 2) + 2 * (y >> 2)] +

  523.                             2 * (x & 3) + 2 * 8 * (y & 3); // FIXME optimize

  524.             int cb = block[4][x + 8 * y];

  525.             int cr = block[5][x + 8 * y];

  526.             int cg = (cb + cr) >> 1;

  527.             int y;

  528. 

  529.             cb += cb;

  530. 

  531.             y               = temp[0];

  532.             dst[0]          = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);

  533.             y               = temp[1];

  534.             dst[1]          = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);

  535.             y               = temp[8];

  536.             dst[stride]     = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);

  537.             y               = temp[9];

  538.             dst[1 + stride] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);

  539.             dst            += 2;

  540.         }

  541.         dst += 2 * stride - 2 * 8;

  542.     }

  543. }

  544. 

  545. static int decode_i_mb(FourXContext *f)

  546. {

  547.     int ret;

  548.     int i;

  549. 

  550.     f->dsp.clear_blocks(f->block[0]);

  551. 

  552.     for (i = 0; i < 6; i++)

  553.         if ((ret = decode_i_block(f, f->block[i])) < 0)

  554.             return ret;

  555. 

  556.     return 0;

  557. }

  558. 

  559. static const uint8_t *read_huffman_tables(FourXContext *f,

  560.                                           const uint8_t * const buf)

  561. {

  562.     int frequency[512] = { 0 };

  563.     uint8_t flag[512];

  564.     int up[512];

  565.     uint8_t len_tab[257];

  566.     int bits_tab[257];

  567.     int start, end;

  568.     const uint8_t *ptr = buf;

  569.     int j;

  570. 

  571.     memset(up, -1, sizeof(up));

  572. 

  573.     start = *ptr++;

  574.     end   = *ptr++;

  575.     for (;;) {

  576.         int i;

  577. 

  578.         for (i = start; i <= end; i++)

  579.             frequency[i] = *ptr++;

  580.         start = *ptr++;

  581.         if (start == 0)

  582.             break;

  583. 

  584.         end = *ptr++;

  585.     }

  586.     frequency[256] = 1;

  587. 

  588.     while ((ptr - buf) & 3)

  589.         ptr++; // 4byte align

  590. 

  591.     for (j = 257; j < 512; j++) {

  592.         int min_freq[2] = { 256 * 256, 256 * 256 };

  593.         int smallest[2] = { 0, 0 };

  594.         int i;

  595.         for (i = 0; i < j; i++) {

  596.             if (frequency[i] == 0)

  597.                 continue;

  598.             if (frequency[i] < min_freq[1]) {

  599.                 if (frequency[i] < min_freq[0]) {

  600.                     min_freq[1] = min_freq[0];

  601.                     smallest[1] = smallest[0];

  602.                     min_freq[0] = frequency[i];

  603.                     smallest[0] = i;

  604.                 } else {

  605.                     min_freq[1] = frequency[i];

  606.                     smallest[1] = i;

  607.                 }

  608.             }

  609.         }

  610.         if (min_freq[1] == 256 * 256)

  611.             break;

  612. 

  613.         frequency[j]           = min_freq[0] + min_freq[1];

  614.         flag[smallest[0]]      = 0;

  615.         flag[smallest[1]]      = 1;

  616.         up[smallest[0]]        =

  617.         up[smallest[1]]        = j;

  618.         frequency[smallest[0]] = frequency[smallest[1]] = 0;

  619.     }

  620. 

  621.     for (j = 0; j < 257; j++) {

  622.         int node, len = 0, bits = 0;

  623. 

  624.         for (node = j; up[node] != -1; node = up[node]) {

  625.             bits += flag[node] << len;

  626.             len++;

  627.             if (len > 31)

  628.                 // can this happen at all ?

  629.                 av_log(f->avctx, AV_LOG_ERROR,

  630.                        "vlc length overflow\n");

  631.         }

  632. 

  633.         bits_tab[j] = bits;

  634.         len_tab[j]  = len;

  635.     }

  636. 

  637.     if (init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257, len_tab, 1, 1,

  638.                  bits_tab, 4, 4, 0))

  639.         return NULL;

  640. 

  641.     return ptr;

  642. }

  643. 

  644. static int mix(int c0, int c1)

  645. {

  646.     int blue  =  2 * (c0 & 0x001F) + (c1 & 0x001F);

  647.     int green = (2 * (c0 & 0x03E0) + (c1 & 0x03E0)) >> 5;

  648.     int red   =  2 * (c0 >> 10)    + (c1 >> 10);

  649.     return red / 3 * 1024 + green / 3 * 32 + blue / 3;

  650. }

  651. 

  652. static int decode_i2_frame(FourXContext *f, AVFrame *frame, const uint8_t *buf, int length)

  653. {

  654.     int x, y, x2, y2;

  655.     const int width  = f->avctx->width;

  656.     const int height = f->avctx->height;

  657.     const int mbs    = (FFALIGN(width, 16) >> 4) * (FFALIGN(height, 16) >> 4);

  658.     uint16_t *dst    = (uint16_t*)frame->data[0];

  659.     const int stride =            frame->linesize[0]>>1;

  660.     GetByteContext g3;

  661. 

  662.     if (length < mbs * 8) {

  663.         av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");

  664.         return AVERROR_INVALIDDATA;

  665.     }

  666.     bytestream2_init(&g3, buf, length);

  667. 

  668.     for (y = 0; y < height; y += 16) {

  669.         for (x = 0; x < width; x += 16) {

  670.             unsigned int color[4] = { 0 }, bits;

  671.             // warning following is purely guessed ...

  672.             color[0] = bytestream2_get_le16u(&g3);

  673.             color[1] = bytestream2_get_le16u(&g3);

  674. 

  675.             if (color[0] & 0x8000)

  676.                 av_log(NULL, AV_LOG_ERROR, "unk bit 1\n");

  677.             if (color[1] & 0x8000)

  678.                 av_log(NULL, AV_LOG_ERROR, "unk bit 2\n");

  679. 

  680.             color[2] = mix(color[0], color[1]);

  681.             color[3] = mix(color[1], color[0]);

  682. 

  683.             bits = bytestream2_get_le32u(&g3);

  684.             for (y2 = 0; y2 < 16; y2++) {

  685.                 for (x2 = 0; x2 < 16; x2++) {

  686.                     int index = 2 * (x2 >> 2) + 8 * (y2 >> 2);

  687.                     dst[y2 * stride + x2] = color[(bits >> index) & 3];

  688.                 }

  689.             }

  690.             dst += 16;

  691.         }

  692.         dst += 16 * stride - x;

  693.     }

  694. 

  695.     return 0;

  696. }

  697. 

  698. static int decode_i_frame(FourXContext *f, AVFrame *frame, const uint8_t *buf, int length)

  699. {

  700.     int x, y, ret;

  701.     const int width  = f->avctx->width;

  702.     const int height = f->avctx->height;

  703.     const unsigned int bitstream_size = AV_RL32(buf);

  704.     int token_count av_unused;

  705.     unsigned int prestream_size;

  706.     const uint8_t *prestream;

  707. 

  708.     if (length < bitstream_size + 12) {

  709.         av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");

  710.         return AVERROR_INVALIDDATA;

  711.     }

  712. 

  713.     token_count    =     AV_RL32(buf + bitstream_size + 8);

  714.     prestream_size = 4 * AV_RL32(buf + bitstream_size + 4);

  715.     prestream      =             buf + bitstream_size + 12;

  716. 

  717.     if (prestream_size + bitstream_size + 12 != length

  718.         || bitstream_size > (1 << 26)

  719.         || prestream_size > (1 << 26)) {

  720.         av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d %d\n",

  721.                prestream_size, bitstream_size, length);

  722.         return AVERROR_INVALIDDATA;

  723.     }

  724. 

  725.     prestream = read_huffman_tables(f, prestream);

  726.     if (!prestream) {

  727.         av_log(f->avctx, AV_LOG_ERROR, "Error reading Huffman tables.\n");

  728.         return AVERROR_INVALIDDATA;

  729.     }

  730. 

  731.     init_get_bits(&f->gb, buf + 4, 8 * bitstream_size);

  732. 

  733.     prestream_size = length + buf - prestream;

  734. 

  735.     av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,

  736.                    prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);

  737.     if (!f->bitstream_buffer)

  738.         return AVERROR(ENOMEM);

  739.     f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)prestream,

  740.                      prestream_size / 4);

  741.     memset((uint8_t*)f->bitstream_buffer + prestream_size,

  742.            0, FF_INPUT_BUFFER_PADDING_SIZE);

  743.     init_get_bits(&f->pre_gb, f->bitstream_buffer, 8 * prestream_size);

  744. 

  745.     f->last_dc = 0 * 128 * 8 * 8;

  746. 

  747.     for (y = 0; y < height; y += 16) {

  748.         for (x = 0; x < width; x += 16) {

  749.             if ((ret = decode_i_mb(f)) < 0)

  750.                 return ret;

  751. 

  752.             idct_put(f, frame, x, y);

  753.         }

  754.     }

  755. 

  756.     if (get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3) != 256)

  757.         av_log(f->avctx, AV_LOG_ERROR, "end mismatch\n");

  758. 

  759.     return 0;

  760. }

  761. 

  762. static int decode_frame(AVCodecContext *avctx, void *data,

  763.                         int *got_frame, AVPacket *avpkt)

  764. {

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

  766.     int buf_size          = avpkt->size;

  767.     FourXContext *const f = avctx->priv_data;

  768.     AVFrame *picture      = data;

  769.     int i, frame_4cc, frame_size, ret;

  770. 

  771.     frame_4cc = AV_RL32(buf);

  772.     if (buf_size != AV_RL32(buf + 4) + 8 || buf_size < 20)

  773.         av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d\n",

  774.                buf_size, AV_RL32(buf + 4));

  775. 

  776.     if (frame_4cc == AV_RL32("cfrm")) {

  777.         int free_index       = -1;

  778.         const int data_size  = buf_size - 20;

  779.         const int id         = AV_RL32(buf + 12);

  780.         const int whole_size = AV_RL32(buf + 16);

  781.         CFrameBuffer *cfrm;

  782. 

  783.         for (i = 0; i < CFRAME_BUFFER_COUNT; i++)

  784.             if (f->cfrm[i].id && f->cfrm[i].id < avctx->frame_number)

  785.                 av_log(f->avctx, AV_LOG_ERROR, "lost c frame %d\n",

  786.                        f->cfrm[i].id);

  787. 

  788.         for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {

  789.             if (f->cfrm[i].id == id)

  790.                 break;

  791.             if (f->cfrm[i].size == 0)

  792.                 free_index = i;

  793.         }

  794. 

  795.         if (i >= CFRAME_BUFFER_COUNT) {

  796.             i             = free_index;

  797.             f->cfrm[i].id = id;

  798.         }

  799.         cfrm = &f->cfrm[i];

  800. 

  801.         cfrm->data = av_fast_realloc(cfrm->data, &cfrm->allocated_size,

  802.                                      cfrm->size + data_size + FF_INPUT_BUFFER_PADDING_SIZE);

  803.         // explicit check needed as memcpy below might not catch a NULL

  804.         if (!cfrm->data) {

  805.             av_log(f->avctx, AV_LOG_ERROR, "realloc failure");

  806.             return AVERROR(ENOMEM);

  807.         }

  808. 

  809.         memcpy(cfrm->data + cfrm->size, buf + 20, data_size);

  810.         cfrm->size += data_size;

  811. 

  812.         if (cfrm->size >= whole_size) {

  813.             buf        = cfrm->data;

  814.             frame_size = cfrm->size;

  815. 

  816.             if (id != avctx->frame_number)

  817.                 av_log(f->avctx, AV_LOG_ERROR, "cframe id mismatch %d %d\n",

  818.                        id, avctx->frame_number);

  819. 

  820.             cfrm->size = cfrm->id = 0;

  821.             frame_4cc  = AV_RL32("pfrm");

  822.         } else

  823.             return buf_size;

  824.     } else {

  825.         buf        = buf      + 12;

  826.         frame_size = buf_size - 12;

  827.     }

  828. 

  829.     // alternatively we would have to use our own buffer management

  830.     avctx->flags |= CODEC_FLAG_EMU_EDGE;

  831. 

  832.     if ((ret = ff_get_buffer(avctx, picture, AV_GET_BUFFER_FLAG_REF)) < 0) {

  833.         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

  834.         return ret;

  835.     }

  836. 

  837.     if (frame_4cc == AV_RL32("ifr2")) {

  838.         picture->pict_type = AV_PICTURE_TYPE_I;

  839.         if ((ret = decode_i2_frame(f, picture, buf - 4, frame_size + 4)) < 0)

  840.             return ret;

  841.     } else if (frame_4cc == AV_RL32("ifrm")) {

  842.         picture->pict_type = AV_PICTURE_TYPE_I;

  843.         if ((ret = decode_i_frame(f, picture, buf, frame_size)) < 0)

  844.             return ret;

  845.     } else if (frame_4cc == AV_RL32("pfrm") || frame_4cc == AV_RL32("pfr2")) {

  846.         if (!f->last_picture->data[0]) {

  847.             if ((ret = ff_get_buffer(avctx, f->last_picture,

  848.                                      AV_GET_BUFFER_FLAG_REF)) < 0) {

  849.                 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

  850.                 return ret;

  851.             }

  852.             memset(f->last_picture->data[0], 0, avctx->height * FFABS(f->last_picture->linesize[0]));

  853.         }

  854. 

  855.         picture->pict_type = AV_PICTURE_TYPE_P;

  856.         if ((ret = decode_p_frame(f, picture, buf, frame_size)) < 0)

  857.             return ret;

  858.     } else if (frame_4cc == AV_RL32("snd_")) {

  859.         av_log(avctx, AV_LOG_ERROR, "ignoring snd_ chunk length:%d\n",

  860.                buf_size);

  861.     } else {

  862.         av_log(avctx, AV_LOG_ERROR, "ignoring unknown chunk length:%d\n",

  863.                buf_size);

  864.     }

  865. 

  866.     picture->key_frame = picture->pict_type == AV_PICTURE_TYPE_I;

  867. 

  868.     av_frame_unref(f->last_picture);

  869.     if ((ret = av_frame_ref(f->last_picture, picture)) < 0)

  870.         return ret;

  871.     *got_frame = 1;

  872. 

  873.     emms_c();

  874. 

  875.     return buf_size;

  876. }

  877. 

  878. static av_cold int decode_init(AVCodecContext *avctx)

  879. {

  880.     FourXContext * const f = avctx->priv_data;

  881. 

  882.     if (avctx->extradata_size != 4 || !avctx->extradata) {

  883.         av_log(avctx, AV_LOG_ERROR, "extradata wrong or missing\n");

  884.         return 1;

  885.     }

  886. 

  887.     f->version = AV_RL32(avctx->extradata) >> 16;

  888.     ff_dsputil_init(&f->dsp, avctx);

  889.     f->avctx = avctx;

  890.     init_vlcs(f);

  891. 

  892.     if (f->version > 2)

  893.         avctx->pix_fmt = AV_PIX_FMT_RGB565;

  894.     else

  895.         avctx->pix_fmt = AV_PIX_FMT_BGR555;

  896. 

  897.     f->last_picture = av_frame_alloc();

  898.     if (!f->last_picture)

  899.         return AVERROR(ENOMEM);

  900. 

  901.     return 0;

  902. }

  903. 

  904. 

  905. static av_cold int decode_end(AVCodecContext *avctx)

  906. {

  907.     FourXContext * const f = avctx->priv_data;

  908.     int i;

  909. 

  910.     av_freep(&f->bitstream_buffer);

  911.     f->bitstream_buffer_size = 0;

  912.     for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {

  913.         av_freep(&f->cfrm[i].data);

  914.         f->cfrm[i].allocated_size = 0;

  915.     }

  916.     ff_free_vlc(&f->pre_vlc);

  917.     av_frame_free(&f->last_picture);

  918. 

  919.     return 0;

  920. }

  921. 

  922. AVCodec ff_fourxm_decoder = {

  923.     .name           = "4xm",

  924.     .type           = AVMEDIA_TYPE_VIDEO,

  925.     .id             = AV_CODEC_ID_4XM,

  926.     .priv_data_size = sizeof(FourXContext),

  927.     .init           = decode_init,

  928.     .close          = decode_end,

  929.     .decode         = decode_frame,

  930.     .capabilities   = CODEC_CAP_DR1,

  931.     .long_name      = NULL_IF_CONFIG_SMALL("4X Movie"),

  932. };