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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. #define BLOCK_TYPE_VLC_BITS 5

  36. #define ACDC_VLC_BITS 9

  37. 

  38. #define CFRAME_BUFFER_COUNT 100

  39. 

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

  41.     {

  42.         {    // { 8, 4, 2 } x { 8, 4, 2}

  43.             { 0, 1 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 30, 5 }, { 31, 5 }, { 0, 0 }

  44.         }, { // { 8, 4 } x 1

  45.             { 0, 1 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }

  46.         }, { // 1 x { 8, 4 }

  47.             { 0, 1 }, { 2, 2 }, { 0, 0 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }

  48.         }, { // 1 x 2, 2 x 1

  49.             { 0, 1 }, { 0, 0 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }

  50.         }

  51.     }, {

  52.         {   // { 8, 4, 2 } x { 8, 4, 2}

  53.             { 1, 2 }, { 4, 3 }, { 5, 3 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }

  54.         }, {// { 8, 4 } x 1

  55.             { 1, 2 }, { 0, 0 }, { 2, 2 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }

  56.         }, {// 1 x { 8, 4 }

  57.             { 1, 2 }, { 2, 2 }, { 0, 0 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }

  58.         }, {// 1 x 2, 2 x 1

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

  60.       }

  61.     }

  62. };

  63. 

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

  65.     { -1, 3, 1, 1 },

  66.     {  3, 0, 0, 0 },

  67.     {  2, 0, 0, 0 },

  68.     {  2, 0, 0, 0 },

  69. };

  70. 

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

  72.     {   0,   0 }, {   0,  -1 }, {  -1,   0 }, {   1,   0 }, {   0,   1 }, {  -1,  -1 }, {   1,  -1 }, {  -1,   1 },

  73.     {   1,   1 }, {   0,  -2 }, {  -2,   0 }, {   2,   0 }, {   0,   2 }, {  -1,  -2 }, {   1,  -2 }, {  -2,  -1 },

  74.     {   2,  -1 }, {  -2,   1 }, {   2,   1 }, {  -1,   2 }, {   1,   2 }, {  -2,  -2 }, {   2,  -2 }, {  -2,   2 },

  75.     {   2,   2 }, {   0,  -3 }, {  -3,   0 }, {   3,   0 }, {   0,   3 }, {  -1,  -3 }, {   1,  -3 }, {  -3,  -1 },

  76.     {   3,  -1 }, {  -3,   1 }, {   3,   1 }, {  -1,   3 }, {   1,   3 }, {  -2,  -3 }, {   2,  -3 }, {  -3,  -2 },

  77.     {   3,  -2 }, {  -3,   2 }, {   3,   2 }, {  -2,   3 }, {   2,   3 }, {   0,  -4 }, {  -4,   0 }, {   4,   0 },

  78.     {   0,   4 }, {  -1,  -4 }, {   1,  -4 }, {  -4,  -1 }, {   4,  -1 }, {   4,   1 }, {  -1,   4 }, {   1,   4 },

  79.     {  -3,  -3 }, {  -3,   3 }, {   3,   3 }, {  -2,  -4 }, {  -4,  -2 }, {   4,  -2 }, {  -4,   2 }, {  -2,   4 },

  80.     {   2,   4 }, {  -3,  -4 }, {   3,  -4 }, {   4,  -3 }, {  -5,   0 }, {  -4,   3 }, {  -3,   4 }, {   3,   4 },

  81.     {  -1,  -5 }, {  -5,  -1 }, {  -5,   1 }, {  -1,   5 }, {  -2,  -5 }, {   2,  -5 }, {   5,  -2 }, {   5,   2 },

  82.     {  -4,  -4 }, {  -4,   4 }, {  -3,  -5 }, {  -5,  -3 }, {  -5,   3 }, {   3,   5 }, {  -6,   0 }, {   0,   6 },

  83.     {  -6,  -1 }, {  -6,   1 }, {   1,   6 }, {   2,  -6 }, {  -6,   2 }, {   2,   6 }, {  -5,  -4 }, {   5,   4 },

  84.     {   4,   5 }, {  -6,  -3 }, {   6,   3 }, {  -7,   0 }, {  -1,  -7 }, {   5,  -5 }, {  -7,   1 }, {  -1,   7 },

  85.     {   4,  -6 }, {   6,   4 }, {  -2,  -7 }, {  -7,   2 }, {  -3,  -7 }, {   7,  -3 }, {   3,   7 }, {   6,  -5 },

  86.     {   0,  -8 }, {  -1,  -8 }, {  -7,  -4 }, {  -8,   1 }, {   4,   7 }, {   2,  -8 }, {  -2,   8 }, {   6,   6 },

  87.     {  -8,   3 }, {   5,  -7 }, {  -5,   7 }, {   8,  -4 }, {   0,  -9 }, {  -9,  -1 }, {   1,   9 }, {   7,  -6 },

  88.     {  -7,   6 }, {  -5,  -8 }, {  -5,   8 }, {  -9,   3 }, {   9,  -4 }, {   7,  -7 }, {   8,  -6 }, {   6,   8 },

  89.     {  10,   1 }, { -10,   2 }, {   9,  -5 }, {  10,  -3 }, {  -8,  -7 }, { -10,  -4 }, {   6,  -9 }, { -11,   0 },

  90.     {  11,   1 }, { -11,  -2 }, {  -2,  11 }, {   7,  -9 }, {  -7,   9 }, {  10,   6 }, {  -4,  11 }, {   8,  -9 },

  91.     {   8,   9 }, {   5,  11 }, {   7, -10 }, {  12,  -3 }, {  11,   6 }, {  -9,  -9 }, {   8,  10 }, {   5,  12 },

  92.     { -11,   7 }, {  13,   2 }, {   6, -12 }, {  10,   9 }, { -11,   8 }, {  -7,  12 }, {   0,  14 }, {  14,  -2 },

  93.     {  -9,  11 }, {  -6,  13 }, { -14,  -4 }, {  -5, -14 }, {   5,  14 }, { -15,  -1 }, { -14,  -6 }, {   3, -15 },

  94.     {  11, -11 }, {  -7,  14 }, {  -5,  15 }, {   8, -14 }, {  15,   6 }, {   3,  16 }, {   7, -15 }, { -16,   5 },

  95.     {   0,  17 }, { -16,  -6 }, { -10,  14 }, { -16,   7 }, {  12,  13 }, { -16,   8 }, { -17,   6 }, { -18,   3 },

  96.     {  -7,  17 }, {  15,  11 }, {  16,  10 }, {   2, -19 }, {   3, -19 }, { -11, -16 }, { -18,   8 }, { -19,  -6 },

  97.     {   2, -20 }, { -17, -11 }, { -10, -18 }, {   8,  19 }, { -21,  -1 }, { -20,   7 }, {  -4,  21 }, {  21,   5 },

  98.     {  15,  16 }, {   2, -22 }, { -10, -20 }, { -22,   5 }, {  20, -11 }, {  -7, -22 }, { -12,  20 }, {  23,  -5 },

  99.     {  13, -20 }, {  24,  -2 }, { -15,  19 }, { -11,  22 }, {  16,  19 }, {  23, -10 }, { -18, -18 }, {  -9, -24 },

  100.     {  24, -10 }, {  -3,  26 }, { -23,  13 }, { -18, -20 }, {  17,  21 }, {  -4,  27 }, {  27,   6 }, {   1, -28 },

  101.     { -11,  26 }, { -17, -23 }, {   7,  28 }, {  11, -27 }, {  29,   5 }, { -23, -19 }, { -28, -11 }, { -21,  22 },

  102.     { -30,   7 }, { -17,  26 }, { -27,  16 }, {  13,  29 }, {  19, -26 }, {  10, -31 }, { -14, -30 }, {  20, -27 },

  103.     { -29,  18 }, { -16, -31 }, { -28, -22 }, {  21, -30 }, { -25,  28 }, {  26, -29 }, {  25, -32 }, { -32, -32 }

  104. };

  105. 

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

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

  108. static const uint8_t dequant_table[64] = {

  109.     16, 15, 13, 19, 24, 31, 28, 17,

  110.     17, 23, 25, 31, 36, 63, 45, 21,

  111.     18, 24, 27, 37, 52, 59, 49, 20,

  112.     16, 28, 34, 40, 60, 80, 51, 20,

  113.     18, 31, 48, 66, 68, 86, 56, 21,

  114.     19, 38, 56, 59, 64, 64, 48, 20,

  115.     27, 48, 55, 55, 56, 51, 35, 15,

  116.     20, 35, 34, 32, 31, 22, 15,  8,

  117. };

  118. 

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

  120. 

  121. 

  122. typedef struct CFrameBuffer {

  123.     unsigned int allocated_size;

  124.     unsigned int size;

  125.     int id;

  126.     uint8_t *data;

  127. } CFrameBuffer;

  128. 

  129. typedef struct FourXContext {

  130.     AVCodecContext *avctx;

  131.     DSPContext dsp;

  132.     AVFrame *last_picture;

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

  134.     GetBitContext gb;

  135.     GetByteContext g;

  136.     GetByteContext g2;

  137.     int mv[256];

  138.     VLC pre_vlc;

  139.     int last_dc;

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

  141.     void *bitstream_buffer;

  142.     unsigned int bitstream_buffer_size;

  143.     int version;

  144.     CFrameBuffer cfrm[CFRAME_BUFFER_COUNT];

  145. } FourXContext;

  146. 

  147. 

  148. #define FIX_1_082392200  70936

  149. #define FIX_1_414213562  92682

  150. #define FIX_1_847759065 121095

  151. #define FIX_2_613125930 171254

  152. 

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

  154. 

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

  156. {

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

  158.     int tmp10, tmp11, tmp12, tmp13;

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

  160.     int i;

  161.     int temp[64];

  162. 

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

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

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

  166. 

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

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

  169. 

  170.         tmp0 = tmp10 + tmp13;

  171.         tmp3 = tmp10 - tmp13;

  172.         tmp1 = tmp11 + tmp12;

  173.         tmp2 = tmp11 - tmp12;

  174. 

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

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

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

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

  179. 

  180.         tmp7  =          z11 + z13;

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

  182. 

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

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

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

  186. 

  187.         tmp6 = tmp12 - tmp7;

  188.         tmp5 = tmp11 - tmp6;

  189.         tmp4 = tmp10 + tmp5;

  190. 

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

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

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

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

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

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

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

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

  199.     }

  200. 

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

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

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

  204. 

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

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

  207. 

  208.         tmp0 = tmp10 + tmp13;

  209.         tmp3 = tmp10 - tmp13;

  210.         tmp1 = tmp11 + tmp12;

  211.         tmp2 = tmp11 - tmp12;

  212. 

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

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

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

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

  217. 

  218.         tmp7  = z11 + z13;

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

  220. 

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

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

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

  224. 

  225.         tmp6 = tmp12 - tmp7;

  226.         tmp5 = tmp11 - tmp6;

  227.         tmp4 = tmp10 + tmp5;

  228. 

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

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

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

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

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

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

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

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

  237.     }

  238. }

  239. 

  240. static av_cold void init_vlcs(FourXContext *f)

  241. {

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

  243.     int i, j;

  244. 

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

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

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

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

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

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

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

  252.                      INIT_VLC_USE_NEW_STATIC);

  253.         }

  254.     }

  255. }

  256. 

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

  258. {

  259.     int i;

  260. 

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

  262.         if (f->version > 1)

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

  264.         else

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

  266.     }

  267. }

  268. 

  269. #if HAVE_BIGENDIAN

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

  271.     {                                                   \

  272.         unsigned tmpval = AV_RN32(src);                 \

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

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

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

  276.         AV_WN32A(dst, tmpval);                          \

  277.     }

  278. #else

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

  280.     {                                                    \

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

  282.         AV_WN32A(dst, tmpval);                           \

  283.     }

  284. #endif

  285. 

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

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

  288. {

  289.     int i;

  290.     dc *= 0x10001;

  291. 

  292.     switch (log2w) {

  293.     case 0:

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

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

  296.             if (scale)

  297.                 src += stride;

  298.             dst += stride;

  299.         }

  300.         break;

  301.     case 1:

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

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

  304.             if (scale)

  305.                 src += stride;

  306.             dst += stride;

  307.         }

  308.         break;

  309.     case 2:

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

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

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

  313.             if (scale)

  314.                 src += stride;

  315.             dst += stride;

  316.         }

  317.         break;

  318.     case 3:

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

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

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

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

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

  324.             if (scale)

  325.                 src += stride;

  326.             dst += stride;

  327.         }

  328.         break;

  329.     default:

  330.         break;

  331.     }

  332. }

  333. 

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

  335.                           int log2w, int log2h, int stride)

  336. {

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

  338.     const int h     = 1 << log2h;

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

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

  341.                                BLOCK_TYPE_VLC_BITS, 1);

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

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

  344.     int ret;

  345.     int scale   = 1;

  346.     unsigned dc = 0;

  347. 

  348.     if (code < 0 || code > 6 || log2w < 0)

  349.         return AVERROR_INVALIDDATA;

  350. 

  351.     if (code == 1) {

  352.         log2h--;

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

  354.             return ret;

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

  356.                               src + (stride << log2h),

  357.                               log2w, log2h, stride);

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

  359.         log2w--;

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

  361.             return ret;

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

  363.                               src + (1 << log2w),

  364.                               log2w, log2h, stride);

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

  366.         if (log2w) {

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

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

  369.         } else {

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

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

  372.         }

  373.         return 0;

  374.     }

  375. 

  376.     if (code == 0) {

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

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

  379.         return 0;

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

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

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

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

  384.         scale = 0;

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

  386.     }

  387. 

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

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

  390.         return AVERROR_INVALIDDATA;

  391.     }

  392. 

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

  394. 

  395.     return 0;

  396. }

  397. 

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

  399.                           const uint8_t *buf, int length)

  400. {

  401.     int x, y;

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

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

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

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

  406.     uint16_t *src;

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

  408.                  bytestream_offset, wordstream_offset;

  409.     int ret;

  410. 

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

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

  413.                                  AV_GET_BUFFER_FLAG_REF)) < 0) {

  414.             av_log(f->avctx, AV_LOG_ERROR, "get_buffer() failed\n");

  415.             return ret;

  416.         }

  417.         memset(f->last_picture->data[0], 0,

  418.                f->avctx->height * FFABS(f->last_picture->linesize[0]));

  419.     }

  420. 

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

  422. 

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

  424.         if (length < 20)

  425.             return AVERROR_INVALIDDATA;

  426.         extra           = 20;

  427.         bitstream_size  = AV_RL32(buf + 8);

  428.         wordstream_size = AV_RL32(buf + 12);

  429.         bytestream_size = AV_RL32(buf + 16);

  430.     } else {

  431.         extra           = 0;

  432.         bitstream_size  = AV_RL16(buf - 4);

  433.         wordstream_size = AV_RL16(buf - 2);

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

  435.     }

  436. 

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

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

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

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

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

  442.                bitstream_size, bytestream_size, wordstream_size,

  443.                bitstream_size + bytestream_size + wordstream_size - length);

  444.         return AVERROR_INVALIDDATA;

  445.     }

  446. 

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

  448.                    bitstream_size + FF_INPUT_BUFFER_PADDING_SIZE);

  449.     if (!f->bitstream_buffer)

  450.         return AVERROR(ENOMEM);

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

  452.                      bitstream_size / 4);

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

  454.            0, FF_INPUT_BUFFER_PADDING_SIZE);

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

  456. 

  457.     wordstream_offset = extra + bitstream_size;

  458.     bytestream_offset = extra + bitstream_size + wordstream_size;

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

  460.                      length - wordstream_offset);

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

  462.                      length - bytestream_offset);

  463. 

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

  465. 

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

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

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

  469.                 return ret;

  470.         src += 8 * stride;

  471.         dst += 8 * stride;

  472.     }

  473. 

  474.     return 0;

  475. }

  476. 

  477. /**

  478.  * decode block and dequantize.

  479.  * Note this is almost identical to MJPEG.

  480.  */

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

  482. {

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

  484. 

  485.     /* DC coef */

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

  487.     if (val >> 4)

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

  489. 

  490.     if (val)

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

  492. 

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

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

  495.     /* AC coefs */

  496.     i = 1;

  497.     for (;;) {

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

  499. 

  500.         /* EOB */

  501.         if (code == 0)

  502.             break;

  503.         if (code == 0xf0) {

  504.             i += 16;

  505.         } else {

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

  507.             i    += code >> 4;

  508.             if (i >= 64) {

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

  510.                 return 0;

  511.             }

  512. 

  513.             j = ff_zigzag_direct[i];

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

  515.             i++;

  516.             if (i >= 64)

  517.                 break;

  518.         }

  519.     }

  520. 

  521.     return 0;

  522. }

  523. 

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

  525. {

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

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

  528.     int i;

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

  530. 

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

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

  533.         idct(block[i]);

  534.     }

  535. 

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

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

  538.             idct(block[i]);

  539.     }

  540. 

  541.     /* Note transform is:

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

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

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

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

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

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

  548.                             2 * (x & 3) + 2 * 8 * (y & 3); // FIXME optimize

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

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

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

  552.             int y;

  553. 

  554.             cb += cb;

  555. 

  556.             y               = temp[0];

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

  558.             y               = temp[1];

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

  560.             y               = temp[8];

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

  562.             y               = temp[9];

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

  564.             dst            += 2;

  565.         }

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

  567.     }

  568. }

  569. 

  570. static int decode_i_mb(FourXContext *f)

  571. {

  572.     int ret;

  573.     int i;

  574. 

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

  576. 

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

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

  579.             return ret;

  580. 

  581.     return 0;

  582. }

  583. 

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

  585.                                           const uint8_t * const buf,

  586.                                           int len)

  587. {

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

  589.     uint8_t flag[512];

  590.     int up[512];

  591.     uint8_t len_tab[257];

  592.     int bits_tab[257];

  593.     int start, end;

  594.     const uint8_t *ptr = buf;

  595.     int j;

  596. 

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

  598. 

  599.     start = *ptr++;

  600.     end   = *ptr++;

  601.     for (;;) {

  602.         int i;

  603. 

  604.         len -= end - start + 1;

  605. 

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

  607.             return NULL;

  608. 

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

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

  611.         start = *ptr++;

  612.         if (start == 0)

  613.             break;

  614. 

  615.         if (--len < 0)

  616.             return NULL;

  617. 

  618.         end = *ptr++;

  619.     }

  620.     frequency[256] = 1;

  621. 

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

  623.         ptr++; // 4byte align

  624. 

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

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

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

  628.         int i;

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

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

  631.                 continue;

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

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

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

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

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

  637.                     smallest[0] = i;

  638.                 } else {

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

  640.                     smallest[1] = i;

  641.                 }

  642.             }

  643.         }

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

  645.             break;

  646. 

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

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

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

  650.         up[smallest[0]]        =

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

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

  653.     }

  654. 

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

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

  657. 

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

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

  660.             len++;

  661.             if (len > 31)

  662.                 // can this happen at all ?

  663.                 av_log(f->avctx, AV_LOG_ERROR,

  664.                        "vlc length overflow\n");

  665.         }

  666. 

  667.         bits_tab[j] = bits;

  668.         len_tab[j]  = len;

  669.     }

  670. 

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

  672.                  bits_tab, 4, 4, 0))

  673.         return NULL;

  674. 

  675.     return ptr;

  676. }

  677. 

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

  679. {

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

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

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

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

  684. }

  685. 

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

  687. {

  688.     int x, y, x2, y2;

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

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

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

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

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

  694.     GetByteContext g3;

  695. 

  696.     if (length < mbs * 8) {

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

  698.         return AVERROR_INVALIDDATA;

  699.     }

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

  701. 

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

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

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

  705.             // warning following is purely guessed ...

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

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

  708. 

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

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

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

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

  713. 

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

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

  716. 

  717.             bits = bytestream2_get_le32u(&g3);

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

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

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

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

  722.                 }

  723.             }

  724.             dst += 16;

  725.         }

  726.         dst += 16 * stride - x;

  727.     }

  728. 

  729.     return 0;

  730. }

  731. 

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

  733. {

  734.     int x, y, ret;

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

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

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

  738.     int token_count av_unused;

  739.     unsigned int prestream_size;

  740.     const uint8_t *prestream;

  741. 

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

  743.         return AVERROR_INVALIDDATA;

  744. 

  745.     if (length < bitstream_size + 12) {

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

  747.         return AVERROR_INVALIDDATA;

  748.     }

  749. 

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

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

  752.     prestream      =             buf + bitstream_size + 12;

  753. 

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

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

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

  757.                prestream_size, bitstream_size, length);

  758.         return AVERROR_INVALIDDATA;

  759.     }

  760. 

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

  762.     if (!prestream) {

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

  764.         return AVERROR_INVALIDDATA;

  765.     }

  766. 

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

  768. 

  769.     prestream_size = length + buf - prestream;

  770. 

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

  772.                    prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);

  773.     if (!f->bitstream_buffer)

  774.         return AVERROR(ENOMEM);

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

  776.                      prestream_size / 4);

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

  778.            0, FF_INPUT_BUFFER_PADDING_SIZE);

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

  780. 

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

  782. 

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

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

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

  786.                 return ret;

  787. 

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

  789.         }

  790.     }

  791. 

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

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

  794. 

  795.     return 0;

  796. }

  797. 

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

  799.                         int *got_frame, AVPacket *avpkt)

  800. {

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

  802.     int buf_size          = avpkt->size;

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

  804.     AVFrame *picture      = data;

  805.     int i, frame_4cc, frame_size, ret;

  806. 

  807.     if (buf_size < 20)

  808.         return AVERROR_INVALIDDATA;

  809. 

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

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

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

  813.         return AVERROR_INVALIDDATA;

  814.     }

  815. 

  816.     frame_4cc = AV_RL32(buf);

  817. 

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

  819.         int free_index       = -1;

  820.         int id, whole_size;

  821.         const int data_size  = buf_size - 20;

  822.         CFrameBuffer *cfrm;

  823. 

  824.         if (data_size < 0)

  825.             return AVERROR_INVALIDDATA;

  826. 

  827.         id         = AV_RL32(buf + 12);

  828.         whole_size = AV_RL32(buf + 16);

  829. 

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

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

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

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

  834. 

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

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

  837.                 break;

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

  839.                 free_index = i;

  840.         }

  841. 

  842.         if (i >= CFRAME_BUFFER_COUNT) {

  843.             i             = free_index;

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

  845.         }

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

  847. 

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

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

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

  851.         if (!cfrm->data) {

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

  853.             return AVERROR(ENOMEM);

  854.         }

  855. 

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

  857.         cfrm->size += data_size;

  858. 

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

  860.             buf        = cfrm->data;

  861.             frame_size = cfrm->size;

  862. 

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

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

  865.                        id, avctx->frame_number);

  866. 

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

  868.                 return AVERROR_INVALIDDATA;

  869. 

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

  871.             frame_4cc  = AV_RL32("pfrm");

  872.         } else

  873.             return buf_size;

  874.     } else {

  875.         buf        = buf      + 12;

  876.         frame_size = buf_size - 12;

  877.     }

  878. 

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

  880.     avctx->flags |= CODEC_FLAG_EMU_EDGE;

  881. 

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

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

  884.         return ret;

  885.     }

  886. 

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

  888.         picture->pict_type = AV_PICTURE_TYPE_I;

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

  890.             return ret;

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

  892.         picture->pict_type = AV_PICTURE_TYPE_I;

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

  894.             return ret;

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

  896.         picture->pict_type = AV_PICTURE_TYPE_P;

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

  898.             return ret;

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

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

  901.                buf_size);

  902.     } else {

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

  904.                buf_size);

  905.     }

  906. 

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

  908. 

  909.     av_frame_unref(f->last_picture);

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

  911.         return ret;

  912.     *got_frame = 1;

  913. 

  914.     emms_c();

  915. 

  916.     return buf_size;

  917. }

  918. 

  919. static av_cold int decode_init(AVCodecContext *avctx)

  920. {

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

  922. 

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

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

  925.         return 1;

  926.     }

  927. 

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

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

  930.     f->avctx = avctx;

  931.     init_vlcs(f);

  932. 

  933.     if (f->version > 2)

  934.         avctx->pix_fmt = AV_PIX_FMT_RGB565;

  935.     else

  936.         avctx->pix_fmt = AV_PIX_FMT_BGR555;

  937. 

  938.     f->last_picture = av_frame_alloc();

  939.     if (!f->last_picture)

  940.         return AVERROR(ENOMEM);

  941. 

  942.     return 0;

  943. }

  944. 

  945. 

  946. static av_cold int decode_end(AVCodecContext *avctx)

  947. {

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

  949.     int i;

  950. 

  951.     av_freep(&f->bitstream_buffer);

  952.     f->bitstream_buffer_size = 0;

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

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

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

  956.     }

  957.     ff_free_vlc(&f->pre_vlc);

  958.     av_frame_free(&f->last_picture);

  959. 

  960.     return 0;

  961. }

  962. 

  963. AVCodec ff_fourxm_decoder = {

  964.     .name           = "4xm",

  965.     .type           = AVMEDIA_TYPE_VIDEO,

  966.     .id             = AV_CODEC_ID_4XM,

  967.     .priv_data_size = sizeof(FourXContext),

  968.     .init           = decode_init,

  969.     .close          = decode_end,

  970.     .decode         = decode_frame,

  971.     .capabilities   = CODEC_CAP_DR1,

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

  973. };