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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 <inttypes.h>

  28. 

  29. #include "libavutil/frame.h"

  30. #include "libavutil/imgutils.h"

  31. #include "libavutil/intreadwrite.h"

  32. 

  33. #include "avcodec.h"

  34. #include "bitstream.h"

  35. #include "blockdsp.h"

  36. #include "bswapdsp.h"

  37. #include "bytestream.h"

  38. #include "internal.h"

  39. #include "vlc.h"

  40. 

  41. #define BLOCK_TYPE_VLC_BITS 5

  42. #define ACDC_VLC_BITS 9

  43. 

  44. #define CFRAME_BUFFER_COUNT 100

  45. 

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

  47.     {

  48.         {    // { 8, 4, 2 } x { 8, 4, 2}

  49.             { 0, 1 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 30, 5 }, { 31, 5 }, { 0, 0 }

  50.         }, { // { 8, 4 } x 1

  51.             { 0, 1 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }

  52.         }, { // 1 x { 8, 4 }

  53.             { 0, 1 }, { 2, 2 }, { 0, 0 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }

  54.         }, { // 1 x 2, 2 x 1

  55.             { 0, 1 }, { 0, 0 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }

  56.         }

  57.     }, {

  58.         {   // { 8, 4, 2 } x { 8, 4, 2}

  59.             { 1, 2 }, { 4, 3 }, { 5, 3 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }

  60.         }, {// { 8, 4 } x 1

  61.             { 1, 2 }, { 0, 0 }, { 2, 2 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }

  62.         }, {// 1 x { 8, 4 }

  63.             { 1, 2 }, { 2, 2 }, { 0, 0 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }

  64.         }, {// 1 x 2, 2 x 1

  65.             { 1, 2 }, { 0, 0 }, { 0, 0 }, { 0, 2 }, { 2, 2 }, { 6, 3 }, { 7, 3 }

  66.       }

  67.     }

  68. };

  69. 

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

  71.     { -1, 3, 1, 1 },

  72.     {  3, 0, 0, 0 },

  73.     {  2, 0, 0, 0 },

  74.     {  2, 0, 0, 0 },

  75. };

  76. 

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

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

  79.     {   1,   1 }, {   0,  -2 }, {  -2,   0 }, {   2,   0 }, {   0,   2 }, {  -1,  -2 }, {   1,  -2 }, {  -2,  -1 },

  80.     {   2,  -1 }, {  -2,   1 }, {   2,   1 }, {  -1,   2 }, {   1,   2 }, {  -2,  -2 }, {   2,  -2 }, {  -2,   2 },

  81.     {   2,   2 }, {   0,  -3 }, {  -3,   0 }, {   3,   0 }, {   0,   3 }, {  -1,  -3 }, {   1,  -3 }, {  -3,  -1 },

  82.     {   3,  -1 }, {  -3,   1 }, {   3,   1 }, {  -1,   3 }, {   1,   3 }, {  -2,  -3 }, {   2,  -3 }, {  -3,  -2 },

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

  84.     {   0,   4 }, {  -1,  -4 }, {   1,  -4 }, {  -4,  -1 }, {   4,  -1 }, {   4,   1 }, {  -1,   4 }, {   1,   4 },

  85.     {  -3,  -3 }, {  -3,   3 }, {   3,   3 }, {  -2,  -4 }, {  -4,  -2 }, {   4,  -2 }, {  -4,   2 }, {  -2,   4 },

  86.     {   2,   4 }, {  -3,  -4 }, {   3,  -4 }, {   4,  -3 }, {  -5,   0 }, {  -4,   3 }, {  -3,   4 }, {   3,   4 },

  87.     {  -1,  -5 }, {  -5,  -1 }, {  -5,   1 }, {  -1,   5 }, {  -2,  -5 }, {   2,  -5 }, {   5,  -2 }, {   5,   2 },

  88.     {  -4,  -4 }, {  -4,   4 }, {  -3,  -5 }, {  -5,  -3 }, {  -5,   3 }, {   3,   5 }, {  -6,   0 }, {   0,   6 },

  89.     {  -6,  -1 }, {  -6,   1 }, {   1,   6 }, {   2,  -6 }, {  -6,   2 }, {   2,   6 }, {  -5,  -4 }, {   5,   4 },

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

  91.     {   4,  -6 }, {   6,   4 }, {  -2,  -7 }, {  -7,   2 }, {  -3,  -7 }, {   7,  -3 }, {   3,   7 }, {   6,  -5 },

  92.     {   0,  -8 }, {  -1,  -8 }, {  -7,  -4 }, {  -8,   1 }, {   4,   7 }, {   2,  -8 }, {  -2,   8 }, {   6,   6 },

  93.     {  -8,   3 }, {   5,  -7 }, {  -5,   7 }, {   8,  -4 }, {   0,  -9 }, {  -9,  -1 }, {   1,   9 }, {   7,  -6 },

  94.     {  -7,   6 }, {  -5,  -8 }, {  -5,   8 }, {  -9,   3 }, {   9,  -4 }, {   7,  -7 }, {   8,  -6 }, {   6,   8 },

  95.     {  10,   1 }, { -10,   2 }, {   9,  -5 }, {  10,  -3 }, {  -8,  -7 }, { -10,  -4 }, {   6,  -9 }, { -11,   0 },

  96.     {  11,   1 }, { -11,  -2 }, {  -2,  11 }, {   7,  -9 }, {  -7,   9 }, {  10,   6 }, {  -4,  11 }, {   8,  -9 },

  97.     {   8,   9 }, {   5,  11 }, {   7, -10 }, {  12,  -3 }, {  11,   6 }, {  -9,  -9 }, {   8,  10 }, {   5,  12 },

  98.     { -11,   7 }, {  13,   2 }, {   6, -12 }, {  10,   9 }, { -11,   8 }, {  -7,  12 }, {   0,  14 }, {  14,  -2 },

  99.     {  -9,  11 }, {  -6,  13 }, { -14,  -4 }, {  -5, -14 }, {   5,  14 }, { -15,  -1 }, { -14,  -6 }, {   3, -15 },

  100.     {  11, -11 }, {  -7,  14 }, {  -5,  15 }, {   8, -14 }, {  15,   6 }, {   3,  16 }, {   7, -15 }, { -16,   5 },

  101.     {   0,  17 }, { -16,  -6 }, { -10,  14 }, { -16,   7 }, {  12,  13 }, { -16,   8 }, { -17,   6 }, { -18,   3 },

  102.     {  -7,  17 }, {  15,  11 }, {  16,  10 }, {   2, -19 }, {   3, -19 }, { -11, -16 }, { -18,   8 }, { -19,  -6 },

  103.     {   2, -20 }, { -17, -11 }, { -10, -18 }, {   8,  19 }, { -21,  -1 }, { -20,   7 }, {  -4,  21 }, {  21,   5 },

  104.     {  15,  16 }, {   2, -22 }, { -10, -20 }, { -22,   5 }, {  20, -11 }, {  -7, -22 }, { -12,  20 }, {  23,  -5 },

  105.     {  13, -20 }, {  24,  -2 }, { -15,  19 }, { -11,  22 }, {  16,  19 }, {  23, -10 }, { -18, -18 }, {  -9, -24 },

  106.     {  24, -10 }, {  -3,  26 }, { -23,  13 }, { -18, -20 }, {  17,  21 }, {  -4,  27 }, {  27,   6 }, {   1, -28 },

  107.     { -11,  26 }, { -17, -23 }, {   7,  28 }, {  11, -27 }, {  29,   5 }, { -23, -19 }, { -28, -11 }, { -21,  22 },

  108.     { -30,   7 }, { -17,  26 }, { -27,  16 }, {  13,  29 }, {  19, -26 }, {  10, -31 }, { -14, -30 }, {  20, -27 },

  109.     { -29,  18 }, { -16, -31 }, { -28, -22 }, {  21, -30 }, { -25,  28 }, {  26, -29 }, {  25, -32 }, { -32, -32 }

  110. };

  111. 

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

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

  114. static const uint8_t dequant_table[64] = {

  115.     16, 15, 13, 19, 24, 31, 28, 17,

  116.     17, 23, 25, 31, 36, 63, 45, 21,

  117.     18, 24, 27, 37, 52, 59, 49, 20,

  118.     16, 28, 34, 40, 60, 80, 51, 20,

  119.     18, 31, 48, 66, 68, 86, 56, 21,

  120.     19, 38, 56, 59, 64, 64, 48, 20,

  121.     27, 48, 55, 55, 56, 51, 35, 15,

  122.     20, 35, 34, 32, 31, 22, 15,  8,

  123. };

  124. 

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

  126. 

  127. 

  128. typedef struct CFrameBuffer {

  129.     unsigned int allocated_size;

  130.     unsigned int size;

  131.     int id;

  132.     uint8_t *data;

  133. } CFrameBuffer;

  134. 

  135. typedef struct FourXContext {

  136.     AVCodecContext *avctx;

  137.     BlockDSPContext bdsp;

  138.     BswapDSPContext bbdsp;

  139.     uint16_t *frame_buffer;

  140.     uint16_t *last_frame_buffer;

  141.     BitstreamContext pre_bc;    // ac/dc prefix

  142.     BitstreamContext bc;

  143.     GetByteContext g;

  144.     GetByteContext g2;

  145.     int mv[256];

  146.     VLC pre_vlc;

  147.     int last_dc;

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

  149.     void *bitstream_buffer;

  150.     unsigned int bitstream_buffer_size;

  151.     int version;

  152.     CFrameBuffer cfrm[CFRAME_BUFFER_COUNT];

  153. } FourXContext;

  154. 

  155. 

  156. #define FIX_1_082392200  70936

  157. #define FIX_1_414213562  92682

  158. #define FIX_1_847759065 121095

  159. #define FIX_2_613125930 171254

  160. 

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

  162. 

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

  164. {

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

  166.     int tmp10, tmp11, tmp12, tmp13;

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

  168.     int i;

  169.     int temp[64];

  170. 

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

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

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

  174. 

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

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

  177. 

  178.         tmp0 = tmp10 + tmp13;

  179.         tmp3 = tmp10 - tmp13;

  180.         tmp1 = tmp11 + tmp12;

  181.         tmp2 = tmp11 - tmp12;

  182. 

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

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

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

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

  187. 

  188.         tmp7  =          z11 + z13;

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

  190. 

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

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

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

  194. 

  195.         tmp6 = tmp12 - tmp7;

  196.         tmp5 = tmp11 - tmp6;

  197.         tmp4 = tmp10 + tmp5;

  198. 

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

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

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

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

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

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

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

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

  207.     }

  208. 

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

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

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

  212. 

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

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

  215. 

  216.         tmp0 = tmp10 + tmp13;

  217.         tmp3 = tmp10 - tmp13;

  218.         tmp1 = tmp11 + tmp12;

  219.         tmp2 = tmp11 - tmp12;

  220. 

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

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

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

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

  225. 

  226.         tmp7  = z11 + z13;

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

  228. 

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

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

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

  232. 

  233.         tmp6 = tmp12 - tmp7;

  234.         tmp5 = tmp11 - tmp6;

  235.         tmp4 = tmp10 + tmp5;

  236. 

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

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

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

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

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

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

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

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

  245.     }

  246. }

  247. 

  248. static av_cold void init_vlcs(FourXContext *f)

  249. {

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

  251.     int i, j;

  252. 

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

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

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

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

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

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

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

  260.                      INIT_VLC_USE_NEW_STATIC);

  261.         }

  262.     }

  263. }

  264. 

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

  266. {

  267.     int i;

  268. 

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

  270.         if (f->version > 1)

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

  272.         else

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

  274.     }

  275. }

  276. 

  277. #if HAVE_BIGENDIAN

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

  279.     {                                                   \

  280.         unsigned tmpval = AV_RN32(src);                 \

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

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

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

  284.         AV_WN32A(dst, tmpval);                          \

  285.     }

  286. #else

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

  288.     {                                                    \

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

  290.         AV_WN32A(dst, tmpval);                           \

  291.     }

  292. #endif

  293. 

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

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

  296. {

  297.     int i;

  298.     dc *= 0x10001;

  299. 

  300.     switch (log2w) {

  301.     case 0:

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

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

  304.             if (scale)

  305.                 src += stride;

  306.             dst += stride;

  307.         }

  308.         break;

  309.     case 1:

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

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

  312.             if (scale)

  313.                 src += stride;

  314.             dst += stride;

  315.         }

  316.         break;

  317.     case 2:

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

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

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

  321.             if (scale)

  322.                 src += stride;

  323.             dst += stride;

  324.         }

  325.         break;

  326.     case 3:

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

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

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

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

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

  332.             if (scale)

  333.                 src += stride;

  334.             dst += stride;

  335.         }

  336.         break;

  337.     default:

  338.         break;

  339.     }

  340. }

  341. 

  342. static int decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src,

  343.                           int log2w, int log2h, int stride)

  344. {

  345.     int index, h, code, ret, scale = 1;

  346.     uint16_t *start, *end;

  347.     unsigned dc = 0;

  348. 

  349.     if (log2h < 0 || log2w < 0)

  350.         return AVERROR_INVALIDDATA;

  351. 

  352.     index = size2index[log2h][log2w];

  353.     if (index < 0)

  354.         return AVERROR_INVALIDDATA;

  355. 

  356.     h     = 1 << log2h;

  357.     code  = bitstream_read_vlc(&f->bc, block_type_vlc[1 - (f->version > 1)][index].table,

  358.                                BLOCK_TYPE_VLC_BITS, 1);

  359.     if (code < 0 || code > 6)

  360.         return AVERROR_INVALIDDATA;

  361. 

  362.     start = f->last_frame_buffer;

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

  364. 

  365.     if (code == 1) {

  366.         if (--log2h < 0)

  367.             return AVERROR_INVALIDDATA;

  368.         if ((ret = decode_p_block(f, dst, src, log2w, log2h, stride)) < 0)

  369.             return ret;

  370.         return decode_p_block(f, dst + (stride << log2h),

  371.                               src + (stride << log2h),

  372.                               log2w, log2h, stride);

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

  374.         log2w--;

  375.         if ((ret = decode_p_block(f, dst , src, log2w, log2h, stride)) < 0)

  376.             return ret;

  377.         return decode_p_block(f, dst + (1 << log2w),

  378.                               src + (1 << log2w),

  379.                               log2w, log2h, stride);

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

  381.         if (log2w) {

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

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

  384.         } else {

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

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

  387.         }

  388.         return 0;

  389.     }

  390. 

  391.     if (code == 0) {

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

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

  394.         return 0;

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

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

  397.         dc    = bytestream2_get_le16(&f->g2);

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

  399.         scale = 0;

  400.         dc    = bytestream2_get_le16(&f->g2);

  401.     }

  402. 

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

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

  405.         return AVERROR_INVALIDDATA;

  406.     }

  407. 

  408.     mcdc(dst, src, log2w, h, stride, scale, dc);

  409. 

  410.     return 0;

  411. }

  412. 

  413. static int decode_p_frame(FourXContext *f, const uint8_t *buf, int length)

  414. {

  415.     int x, y;

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

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

  418.     uint16_t *dst    = f->frame_buffer;

  419.     uint16_t *src;

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

  421.                  bytestream_offset, wordstream_offset;

  422.     int ret;

  423. 

  424.     src = f->last_frame_buffer;

  425. 

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

  427.         if (length < 20)

  428.             return AVERROR_INVALIDDATA;

  429.         extra           = 20;

  430.         bitstream_size  = AV_RL32(buf + 8);

  431.         wordstream_size = AV_RL32(buf + 12);

  432.         bytestream_size = AV_RL32(buf + 16);

  433.     } else {

  434.         extra           = 0;

  435.         bitstream_size  = AV_RL16(buf - 4);

  436.         wordstream_size = AV_RL16(buf - 2);

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

  438.     }

  439. 

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

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

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

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

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

  445.                bitstream_size, bytestream_size, wordstream_size,

  446.                bitstream_size + bytestream_size + wordstream_size - length);

  447.         return AVERROR_INVALIDDATA;

  448.     }

  449. 

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

  451.                    bitstream_size + AV_INPUT_BUFFER_PADDING_SIZE);

  452.     if (!f->bitstream_buffer)

  453.         return AVERROR(ENOMEM);

  454.     f->bbdsp.bswap_buf(f->bitstream_buffer, (const uint32_t *) (buf + extra),

  455.                        bitstream_size / 4);

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

  457.            0, AV_INPUT_BUFFER_PADDING_SIZE);

  458.     bitstream_init8(&f->bc, f->bitstream_buffer, bitstream_size);

  459. 

  460.     wordstream_offset = extra + bitstream_size;

  461.     bytestream_offset = extra + bitstream_size + wordstream_size;

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

  463.                      length - wordstream_offset);

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

  465.                      length - bytestream_offset);

  466. 

  467.     init_mv(f, width * 2);

  468. 

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

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

  471.             if ((ret = decode_p_block(f, dst + x, src + x, 3, 3, width)) < 0)

  472.                 return ret;

  473.         src += 8 * width;

  474.         dst += 8 * width;

  475.     }

  476. 

  477.     return 0;

  478. }

  479. 

  480. /**

  481.  * decode block and dequantize.

  482.  * Note this is almost identical to MJPEG.

  483.  */

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

  485. {

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

  487. 

  488.     /* DC coef */

  489.     val = bitstream_read_vlc(&f->pre_bc, f->pre_vlc.table, ACDC_VLC_BITS, 3);

  490.     if (val >> 4)

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

  492. 

  493.     if (val)

  494.         val = bitstream_read_xbits(&f->bc, val);

  495. 

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

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

  498.     /* AC coefs */

  499.     i = 1;

  500.     for (;;) {

  501.         code = bitstream_read_vlc(&f->pre_bc, f->pre_vlc.table, ACDC_VLC_BITS, 3);

  502. 

  503.         /* EOB */

  504.         if (code == 0)

  505.             break;

  506.         if (code == 0xf0) {

  507.             i += 16;

  508.         } else {

  509.             level = bitstream_read_xbits(&f->bc, code & 0xf);

  510.             i    += code >> 4;

  511.             if (i >= 64) {

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

  513.                 return 0;

  514.             }

  515. 

  516.             j = ff_zigzag_direct[i];

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

  518.             i++;

  519.             if (i >= 64)

  520.                 break;

  521.         }

  522.     }

  523. 

  524.     return 0;

  525. }

  526. 

  527. static inline void idct_put(FourXContext *f, int x, int y)

  528. {

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

  530.     int stride           = f->avctx->width;

  531.     int i;

  532.     uint16_t *dst = f->frame_buffer + y * stride + x;

  533. 

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

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

  536.         idct(block[i]);

  537.     }

  538. 

  539.     if (!(f->avctx->flags & AV_CODEC_FLAG_GRAY)) {

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

  541.             idct(block[i]);

  542.     }

  543. 

  544.     /* Note transform is:

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

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

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

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

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

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

  551.                             2 * (x & 3) + 2 * 8 * (y & 3); // FIXME optimize

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

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

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

  555.             int y;

  556. 

  557.             cb += cb;

  558. 

  559.             y               = temp[0];

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

  561.             y               = temp[1];

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

  563.             y               = temp[8];

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

  565.             y               = temp[9];

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

  567.             dst            += 2;

  568.         }

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

  570.     }

  571. }

  572. 

  573. static int decode_i_mb(FourXContext *f)

  574. {

  575.     int ret;

  576.     int i;

  577. 

  578.     f->bdsp.clear_blocks(f->block[0]);

  579. 

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

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

  582.             return ret;

  583. 

  584.     return 0;

  585. }

  586. 

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

  588.                                           const uint8_t * const buf,

  589.                                           int len)

  590. {

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

  592.     uint8_t flag[512];

  593.     int up[512];

  594.     uint8_t len_tab[257];

  595.     int bits_tab[257];

  596.     int start, end;

  597.     const uint8_t *ptr = buf;

  598.     int j;

  599. 

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

  601. 

  602.     start = *ptr++;

  603.     end   = *ptr++;

  604.     for (;;) {

  605.         int i;

  606. 

  607.         len -= end - start + 1;

  608. 

  609.         if (end < start || len < 0)

  610.             return NULL;

  611. 

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

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

  614.         start = *ptr++;

  615.         if (start == 0)

  616.             break;

  617. 

  618.         if (--len < 0)

  619.             return NULL;

  620. 

  621.         end = *ptr++;

  622.     }

  623.     frequency[256] = 1;

  624. 

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

  626.         ptr++; // 4byte align

  627. 

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

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

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

  631.         int i;

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

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

  634.                 continue;

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

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

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

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

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

  640.                     smallest[0] = i;

  641.                 } else {

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

  643.                     smallest[1] = i;

  644.                 }

  645.             }

  646.         }

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

  648.             break;

  649. 

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

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

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

  653.         up[smallest[0]]        =

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

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

  656.     }

  657. 

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

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

  660. 

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

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

  663.             len++;

  664.             if (len > 31)

  665.                 // can this happen at all ?

  666.                 av_log(f->avctx, AV_LOG_ERROR,

  667.                        "vlc length overflow\n");

  668.         }

  669. 

  670.         bits_tab[j] = bits;

  671.         len_tab[j]  = len;

  672.     }

  673. 

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

  675.                  bits_tab, 4, 4, 0))

  676.         return NULL;

  677. 

  678.     return ptr;

  679. }

  680. 

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

  682. {

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

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

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

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

  687. }

  688. 

  689. static int decode_i2_frame(FourXContext *f, const uint8_t *buf, int length)

  690. {

  691.     int x, y, x2, y2;

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

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

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

  695.     uint16_t *dst    = f->frame_buffer;

  696.     GetByteContext g3;

  697. 

  698.     if (length < mbs * 8) {

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

  700.         return AVERROR_INVALIDDATA;

  701.     }

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

  703. 

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

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

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

  707.             // warning following is purely guessed ...

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

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

  710. 

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

  712.                 av_log(f->avctx, AV_LOG_ERROR, "unk bit 1\n");

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

  714.                 av_log(f->avctx, AV_LOG_ERROR, "unk bit 2\n");

  715. 

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

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

  718. 

  719.             bits = bytestream2_get_le32u(&g3);

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

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

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

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

  724.                 }

  725.             }

  726.             dst += 16;

  727.         }

  728.         dst += 16 * width - x;

  729.     }

  730. 

  731.     return 0;

  732. }

  733. 

  734. static int decode_i_frame(FourXContext *f, const uint8_t *buf, int length)

  735. {

  736.     int x, y, ret;

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

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

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

  740.     int token_count av_unused;

  741.     unsigned int prestream_size;

  742.     const uint8_t *prestream;

  743. 

  744.     if (bitstream_size > (1 << 26))

  745.         return AVERROR_INVALIDDATA;

  746. 

  747.     if (length < bitstream_size + 12) {

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

  749.         return AVERROR_INVALIDDATA;

  750.     }

  751. 

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

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

  754.     prestream      =             buf + bitstream_size + 12;

  755. 

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

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

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

  759.                prestream_size, bitstream_size, length);

  760.         return AVERROR_INVALIDDATA;

  761.     }

  762. 

  763.     prestream = read_huffman_tables(f, prestream, prestream_size);

  764.     if (!prestream) {

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

  766.         return AVERROR_INVALIDDATA;

  767.     }

  768. 

  769.     bitstream_init8(&f->bc, buf + 4, bitstream_size);

  770. 

  771.     prestream_size = length + buf - prestream;

  772. 

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

  774.                    prestream_size + AV_INPUT_BUFFER_PADDING_SIZE);

  775.     if (!f->bitstream_buffer)

  776.         return AVERROR(ENOMEM);

  777.     f->bbdsp.bswap_buf(f->bitstream_buffer, (const uint32_t *) prestream,

  778.                        prestream_size / 4);

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

  780.            0, AV_INPUT_BUFFER_PADDING_SIZE);

  781.     bitstream_init8(&f->pre_bc, f->bitstream_buffer, prestream_size);

  782. 

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

  784. 

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

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

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

  788.                 return ret;

  789. 

  790.             idct_put(f, x, y);

  791.         }

  792.     }

  793. 

  794.     if (bitstream_read_vlc(&f->pre_bc, f->pre_vlc.table, ACDC_VLC_BITS, 3) != 256)

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

  796. 

  797.     return 0;

  798. }

  799. 

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

  801.                         int *got_frame, AVPacket *avpkt)

  802. {

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

  804.     int buf_size          = avpkt->size;

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

  806.     AVFrame *picture      = data;

  807.     int i, frame_4cc, frame_size, ret;

  808. 

  809.     if (buf_size < 20)

  810.         return AVERROR_INVALIDDATA;

  811. 

  812.     if (avctx->width % 16 || avctx->height % 16) {

  813.         av_log(avctx, AV_LOG_ERROR,

  814.                "Dimensions non-multiple of 16 are invalid.\n");

  815.         return AVERROR_INVALIDDATA;

  816.     }

  817. 

  818.     if (buf_size < AV_RL32(buf + 4) + 8) {

  819.         av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %"PRIu32"\n",

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

  821.         return AVERROR_INVALIDDATA;

  822.     }

  823. 

  824.     frame_4cc = AV_RL32(buf);

  825. 

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

  827.         int free_index       = -1;

  828.         int id, whole_size;

  829.         const int data_size  = buf_size - 20;

  830.         CFrameBuffer *cfrm;

  831. 

  832.         id         = AV_RL32(buf + 12);

  833.         whole_size = AV_RL32(buf + 16);

  834. 

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

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

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

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

  839. 

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

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

  842.                 break;

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

  844.                 free_index = i;

  845.         }

  846. 

  847.         if (i >= CFRAME_BUFFER_COUNT) {

  848.             i             = free_index;

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

  850.         }

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

  852. 

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

  854.                                      cfrm->size + data_size + AV_INPUT_BUFFER_PADDING_SIZE);

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

  856.         if (!cfrm->data) {

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

  858.             return AVERROR(ENOMEM);

  859.         }

  860. 

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

  862.         cfrm->size += data_size;

  863. 

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

  865.             buf        = cfrm->data;

  866.             frame_size = cfrm->size;

  867. 

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

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

  870.                        id, avctx->frame_number);

  871. 

  872.             if (f->version <= 1)

  873.                 return AVERROR_INVALIDDATA;

  874. 

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

  876.             frame_4cc  = AV_RL32("pfrm");

  877.         } else

  878.             return buf_size;

  879.     } else {

  880.         buf        = buf      + 12;

  881.         frame_size = buf_size - 12;

  882.     }

  883. 

  884. 

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

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

  887.         return ret;

  888.     }

  889. 

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

  891.         picture->pict_type = AV_PICTURE_TYPE_I;

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

  893.             return ret;

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

  895.         picture->pict_type = AV_PICTURE_TYPE_I;

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

  897.             return ret;

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

  899.         picture->pict_type = AV_PICTURE_TYPE_P;

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

  901.             return ret;

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

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

  904.                buf_size);

  905.     } else {

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

  907.                buf_size);

  908.     }

  909. 

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

  911. 

  912.     av_image_copy_plane(picture->data[0], picture->linesize[0],

  913.                         (const uint8_t*)f->frame_buffer,  avctx->width * 2,

  914.                         avctx->width * 2, avctx->height);

  915.     FFSWAP(uint16_t *, f->frame_buffer, f->last_frame_buffer);

  916. 

  917.     *got_frame = 1;

  918. 

  919.     emms_c();

  920. 

  921.     return buf_size;

  922. }

  923. 

  924. static av_cold int decode_end(AVCodecContext *avctx)

  925. {

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

  927.     int i;

  928. 

  929.     av_freep(&f->frame_buffer);

  930.     av_freep(&f->last_frame_buffer);

  931.     av_freep(&f->bitstream_buffer);

  932.     f->bitstream_buffer_size = 0;

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

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

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

  936.     }

  937.     ff_free_vlc(&f->pre_vlc);

  938. 

  939.     return 0;

  940. }

  941. 

  942. static av_cold int decode_init(AVCodecContext *avctx)

  943. {

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

  945.     int ret;

  946. 

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

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

  949.         return AVERROR_INVALIDDATA;

  950.     }

  951. 

  952.     ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);

  953.     if (ret < 0)

  954.         return ret;

  955. 

  956.     f->frame_buffer      = av_mallocz(avctx->width * avctx->height * 2);

  957.     f->last_frame_buffer = av_mallocz(avctx->width * avctx->height * 2);

  958.     if (!f->frame_buffer || !f->last_frame_buffer) {

  959.         decode_end(avctx);

  960.         return AVERROR(ENOMEM);

  961.     }

  962. 

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

  964.     ff_blockdsp_init(&f->bdsp);

  965.     ff_bswapdsp_init(&f->bbdsp);

  966.     f->avctx = avctx;

  967.     init_vlcs(f);

  968. 

  969.     if (f->version > 2)

  970.         avctx->pix_fmt = AV_PIX_FMT_RGB565;

  971.     else

  972.         avctx->pix_fmt = AV_PIX_FMT_BGR555;

  973. 

  974.     return 0;

  975. }

  976. 

  977. AVCodec ff_fourxm_decoder = {

  978.     .name           = "4xm",

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

  980.     .type           = AVMEDIA_TYPE_VIDEO,

  981.     .id             = AV_CODEC_ID_4XM,

  982.     .priv_data_size = sizeof(FourXContext),

  983.     .init           = decode_init,

  984.     .close          = decode_end,

  985.     .decode         = decode_frame,

  986.     .capabilities   = AV_CODEC_CAP_DR1,

  987. };