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FFmpeg/libavcodec/mjpeg.c

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  1. /*

  2.  * MJPEG encoder and decoder

  3.  * Copyright (c) 2000, 2001 Fabrice Bellard.

  4.  *

  5.  * This library is free software; you can redistribute it and/or

  6.  * modify it under the terms of the GNU Lesser General Public

  7.  * License as published by the Free Software Foundation; either

  8.  * version 2 of the License, or (at your option) any later version.

  9.  *

  10.  * This library is distributed in the hope that it will be useful,

  11.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  12.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  13.  * Lesser General Public License for more details.

  14.  *

  15.  * You should have received a copy of the GNU Lesser General Public

  16.  * License along with this library; if not, write to the Free Software

  17.  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  18.  *

  19.  * Support for external huffman table, various fixes (AVID workaround),

  20.  * aspecting, new decode_frame mechanism and apple mjpeg-b support

  21.  *                                  by Alex Beregszaszi <alex@naxine.org>

  22.  */

  23. 

  24. /**

  25.  * @file mjpeg.c

  26.  * MJPEG encoder and decoder.

  27.  */

  28.  

  29. //#define DEBUG

  30. #include "avcodec.h"

  31. #include "dsputil.h"

  32. #include "mpegvideo.h"

  33. 

  34. /* use two quantizer tables (one for luminance and one for chrominance) */

  35. /* not yet working */

  36. #undef TWOMATRIXES

  37. 

  38. typedef struct MJpegContext {

  39.     uint8_t huff_size_dc_luminance[12];

  40.     uint16_t huff_code_dc_luminance[12];

  41.     uint8_t huff_size_dc_chrominance[12];

  42.     uint16_t huff_code_dc_chrominance[12];

  43. 

  44.     uint8_t huff_size_ac_luminance[256];

  45.     uint16_t huff_code_ac_luminance[256];

  46.     uint8_t huff_size_ac_chrominance[256];

  47.     uint16_t huff_code_ac_chrominance[256];

  48. } MJpegContext;

  49. 

  50. /* JPEG marker codes */

  51. typedef enum {

  52.     /* start of frame */

  53.     SOF0  = 0xc0,	/* baseline */

  54.     SOF1  = 0xc1,	/* extended sequential, huffman */

  55.     SOF2  = 0xc2,	/* progressive, huffman */

  56.     SOF3  = 0xc3,	/* lossless, huffman */

  57. 

  58.     SOF5  = 0xc5,	/* differential sequential, huffman */

  59.     SOF6  = 0xc6,	/* differential progressive, huffman */

  60.     SOF7  = 0xc7,	/* differential lossless, huffman */

  61.     JPG   = 0xc8,	/* reserved for JPEG extension */

  62.     SOF9  = 0xc9,	/* extended sequential, arithmetic */

  63.     SOF10 = 0xca,	/* progressive, arithmetic */

  64.     SOF11 = 0xcb,	/* lossless, arithmetic */

  65. 

  66.     SOF13 = 0xcd,	/* differential sequential, arithmetic */

  67.     SOF14 = 0xce,	/* differential progressive, arithmetic */

  68.     SOF15 = 0xcf,	/* differential lossless, arithmetic */

  69. 

  70.     DHT   = 0xc4,	/* define huffman tables */

  71. 

  72.     DAC   = 0xcc,	/* define arithmetic-coding conditioning */

  73. 

  74.     /* restart with modulo 8 count "m" */

  75.     RST0  = 0xd0,

  76.     RST1  = 0xd1,

  77.     RST2  = 0xd2,

  78.     RST3  = 0xd3,

  79.     RST4  = 0xd4,

  80.     RST5  = 0xd5,

  81.     RST6  = 0xd6,

  82.     RST7  = 0xd7,

  83. 

  84.     SOI   = 0xd8,	/* start of image */

  85.     EOI   = 0xd9,	/* end of image */

  86.     SOS   = 0xda,	/* start of scan */

  87.     DQT   = 0xdb,	/* define quantization tables */

  88.     DNL   = 0xdc,	/* define number of lines */

  89.     DRI   = 0xdd,	/* define restart interval */

  90.     DHP   = 0xde,	/* define hierarchical progression */

  91.     EXP   = 0xdf,	/* expand reference components */

  92. 

  93.     APP0  = 0xe0,

  94.     APP1  = 0xe1,

  95.     APP2  = 0xe2,

  96.     APP3  = 0xe3,

  97.     APP4  = 0xe4,

  98.     APP5  = 0xe5,

  99.     APP6  = 0xe6,

  100.     APP7  = 0xe7,

  101.     APP8  = 0xe8,

  102.     APP9  = 0xe9,

  103.     APP10 = 0xea,

  104.     APP11 = 0xeb,

  105.     APP12 = 0xec,

  106.     APP13 = 0xed,

  107.     APP14 = 0xee,

  108.     APP15 = 0xef,

  109. 

  110.     JPG0  = 0xf0,

  111.     JPG1  = 0xf1,

  112.     JPG2  = 0xf2,

  113.     JPG3  = 0xf3,

  114.     JPG4  = 0xf4,

  115.     JPG5  = 0xf5,

  116.     JPG6  = 0xf6,

  117.     JPG7  = 0xf7,

  118.     JPG8  = 0xf8,

  119.     JPG9  = 0xf9,

  120.     JPG10 = 0xfa,

  121.     JPG11 = 0xfb,

  122.     JPG12 = 0xfc,

  123.     JPG13 = 0xfd,

  124. 

  125.     COM   = 0xfe,	/* comment */

  126. 

  127.     TEM   = 0x01,	/* temporary private use for arithmetic coding */

  128. 

  129.     /* 0x02 -> 0xbf reserved */

  130. } JPEG_MARKER;

  131. 

  132. #if 0

  133. /* These are the sample quantization tables given in JPEG spec section K.1.

  134.  * The spec says that the values given produce "good" quality, and

  135.  * when divided by 2, "very good" quality.

  136.  */

  137. static const unsigned char std_luminance_quant_tbl[64] = {

  138.     16,  11,  10,  16,  24,  40,  51,  61,

  139.     12,  12,  14,  19,  26,  58,  60,  55,

  140.     14,  13,  16,  24,  40,  57,  69,  56,

  141.     14,  17,  22,  29,  51,  87,  80,  62,

  142.     18,  22,  37,  56,  68, 109, 103,  77,

  143.     24,  35,  55,  64,  81, 104, 113,  92,

  144.     49,  64,  78,  87, 103, 121, 120, 101,

  145.     72,  92,  95,  98, 112, 100, 103,  99

  146. };

  147. static const unsigned char std_chrominance_quant_tbl[64] = {

  148.     17,  18,  24,  47,  99,  99,  99,  99,

  149.     18,  21,  26,  66,  99,  99,  99,  99,

  150.     24,  26,  56,  99,  99,  99,  99,  99,

  151.     47,  66,  99,  99,  99,  99,  99,  99,

  152.     99,  99,  99,  99,  99,  99,  99,  99,

  153.     99,  99,  99,  99,  99,  99,  99,  99,

  154.     99,  99,  99,  99,  99,  99,  99,  99,

  155.     99,  99,  99,  99,  99,  99,  99,  99

  156. };

  157. #endif

  158. 

  159. /* Set up the standard Huffman tables (cf. JPEG standard section K.3) */

  160. /* IMPORTANT: these are only valid for 8-bit data precision! */

  161. static const uint8_t bits_dc_luminance[17] =

  162. { /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 };

  163. static const uint8_t val_dc_luminance[] =

  164. { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };

  165. 

  166. static const uint8_t bits_dc_chrominance[17] =

  167. { /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };

  168. static const uint8_t val_dc_chrominance[] =

  169. { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };

  170. 

  171. static const uint8_t bits_ac_luminance[17] =

  172. { /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d };

  173. static const uint8_t val_ac_luminance[] =

  174. { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,

  175.   0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,

  176.   0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,

  177.   0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,

  178.   0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,

  179.   0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,

  180.   0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,

  181.   0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,

  182.   0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,

  183.   0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,

  184.   0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,

  185.   0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,

  186.   0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,

  187.   0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,

  188.   0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,

  189.   0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,

  190.   0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,

  191.   0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,

  192.   0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,

  193.   0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,

  194.   0xf9, 0xfa 

  195. };

  196. 

  197. static const uint8_t bits_ac_chrominance[17] =

  198. { /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 };

  199. 

  200. static const uint8_t val_ac_chrominance[] =

  201. { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,

  202.   0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,

  203.   0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,

  204.   0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,

  205.   0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,

  206.   0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,

  207.   0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,

  208.   0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,

  209.   0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,

  210.   0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,

  211.   0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,

  212.   0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,

  213.   0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,

  214.   0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,

  215.   0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,

  216.   0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,

  217.   0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,

  218.   0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,

  219.   0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,

  220.   0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,

  221.   0xf9, 0xfa 

  222. };

  223. 

  224. /* isn't this function nicer than the one in the libjpeg ? */

  225. static void build_huffman_codes(uint8_t *huff_size, uint16_t *huff_code,

  226.                                 const uint8_t *bits_table, const uint8_t *val_table)

  227. {

  228.     int i, j, k,nb, code, sym;

  229. 

  230.     code = 0;

  231.     k = 0;

  232.     for(i=1;i<=16;i++) {

  233.         nb = bits_table[i];

  234.         for(j=0;j<nb;j++) {

  235.             sym = val_table[k++];

  236.             huff_size[sym] = i;

  237.             huff_code[sym] = code;

  238.             code++;

  239.         }

  240.         code <<= 1;

  241.     }

  242. }

  243. 

  244. int mjpeg_init(MpegEncContext *s)

  245. {

  246.     MJpegContext *m;

  247.     

  248.     m = av_malloc(sizeof(MJpegContext));

  249.     if (!m)

  250.         return -1;

  251.     

  252.     s->min_qcoeff=-1023;

  253.     s->max_qcoeff= 1023;

  254. 

  255.     /* build all the huffman tables */

  256.     build_huffman_codes(m->huff_size_dc_luminance,

  257.                         m->huff_code_dc_luminance,

  258.                         bits_dc_luminance,

  259.                         val_dc_luminance);

  260.     build_huffman_codes(m->huff_size_dc_chrominance,

  261.                         m->huff_code_dc_chrominance,

  262.                         bits_dc_chrominance,

  263.                         val_dc_chrominance);

  264.     build_huffman_codes(m->huff_size_ac_luminance,

  265.                         m->huff_code_ac_luminance,

  266.                         bits_ac_luminance,

  267.                         val_ac_luminance);

  268.     build_huffman_codes(m->huff_size_ac_chrominance,

  269.                         m->huff_code_ac_chrominance,

  270.                         bits_ac_chrominance,

  271.                         val_ac_chrominance);

  272.     

  273.     s->mjpeg_ctx = m;

  274.     return 0;

  275. }

  276. 

  277. void mjpeg_close(MpegEncContext *s)

  278. {

  279.     av_free(s->mjpeg_ctx);

  280. }

  281. 

  282. static inline void put_marker(PutBitContext *p, int code)

  283. {

  284.     put_bits(p, 8, 0xff);

  285.     put_bits(p, 8, code);

  286. }

  287. 

  288. /* table_class: 0 = DC coef, 1 = AC coefs */

  289. static int put_huffman_table(MpegEncContext *s, int table_class, int table_id,

  290.                              const uint8_t *bits_table, const uint8_t *value_table)

  291. {

  292.     PutBitContext *p = &s->pb;

  293.     int n, i;

  294. 

  295.     put_bits(p, 4, table_class);

  296.     put_bits(p, 4, table_id);

  297. 

  298.     n = 0;

  299.     for(i=1;i<=16;i++) {

  300.         n += bits_table[i];

  301.         put_bits(p, 8, bits_table[i]);

  302.     }

  303. 

  304.     for(i=0;i<n;i++)

  305.         put_bits(p, 8, value_table[i]);

  306. 

  307.     return n + 17;

  308. }

  309. 

  310. static void jpeg_table_header(MpegEncContext *s)

  311. {

  312.     PutBitContext *p = &s->pb;

  313.     int i, j, size;

  314.     uint8_t *ptr;

  315. 

  316.     /* quant matrixes */

  317.     put_marker(p, DQT);

  318. #ifdef TWOMATRIXES

  319.     put_bits(p, 16, 2 + 2 * (1 + 64));

  320. #else

  321.     put_bits(p, 16, 2 + 1 * (1 + 64));

  322. #endif

  323.     put_bits(p, 4, 0); /* 8 bit precision */

  324.     put_bits(p, 4, 0); /* table 0 */

  325.     for(i=0;i<64;i++) {

  326.         j = s->intra_scantable.permutated[i];

  327.         put_bits(p, 8, s->intra_matrix[j]);

  328.     }

  329. #ifdef TWOMATRIXES

  330.     put_bits(p, 4, 0); /* 8 bit precision */

  331.     put_bits(p, 4, 1); /* table 1 */

  332.     for(i=0;i<64;i++) {

  333.         j = s->intra_scantable.permutated[i];

  334.         put_bits(p, 8, s->chroma_intra_matrix[j]);

  335.     }

  336. #endif

  337. 

  338.     /* huffman table */

  339.     put_marker(p, DHT);

  340.     flush_put_bits(p);

  341.     ptr = pbBufPtr(p);

  342.     put_bits(p, 16, 0); /* patched later */

  343.     size = 2;

  344.     size += put_huffman_table(s, 0, 0, bits_dc_luminance, val_dc_luminance);

  345.     size += put_huffman_table(s, 0, 1, bits_dc_chrominance, val_dc_chrominance);

  346.     

  347.     size += put_huffman_table(s, 1, 0, bits_ac_luminance, val_ac_luminance);

  348.     size += put_huffman_table(s, 1, 1, bits_ac_chrominance, val_ac_chrominance);

  349.     ptr[0] = size >> 8;

  350.     ptr[1] = size;

  351. }

  352. 

  353. static void jpeg_put_comments(MpegEncContext *s)

  354. {

  355.     PutBitContext *p = &s->pb;

  356.     int size;

  357.     uint8_t *ptr;

  358. 

  359.     if (s->aspect_ratio_info)

  360.     {

  361.     /* JFIF header */

  362.     put_marker(p, APP0);

  363.     put_bits(p, 16, 16);

  364.     put_string(p, "JFIF"); /* this puts the trailing zero-byte too */

  365.     put_bits(p, 16, 0x0201); /* v 1.02 */

  366.     put_bits(p, 8, 0); /* units type: 0 - aspect ratio */

  367.     switch(s->aspect_ratio_info)

  368.     {

  369. 	case FF_ASPECT_4_3_625:

  370. 	case FF_ASPECT_4_3_525:

  371. 	    put_bits(p, 16, 4); 

  372. 	    put_bits(p, 16, 3);

  373. 	    break;

  374. 	case FF_ASPECT_16_9_625:

  375. 	case FF_ASPECT_16_9_525:

  376. 	    put_bits(p, 16, 16); 

  377. 	    put_bits(p, 16, 9);

  378. 	    break;

  379. 	case FF_ASPECT_EXTENDED:

  380. 	    put_bits(p, 16, s->aspected_width);

  381. 	    put_bits(p, 16, s->aspected_height);

  382. 	    break;

  383. 	case FF_ASPECT_SQUARE:

  384. 	default:

  385. 	    put_bits(p, 16, 1); /* aspect: 1:1 */

  386. 	    put_bits(p, 16, 1);

  387. 	    break;

  388.     }

  389.     put_bits(p, 8, 0); /* thumbnail width */

  390.     put_bits(p, 8, 0); /* thumbnail height */

  391.     }

  392. 

  393.     /* comment */

  394.     if(!(s->flags & CODEC_FLAG_BITEXACT)){

  395.         put_marker(p, COM);

  396.         flush_put_bits(p);

  397.         ptr = pbBufPtr(p);

  398.         put_bits(p, 16, 0); /* patched later */

  399.         put_string(p, LIBAVCODEC_IDENT);

  400.         size = strlen(LIBAVCODEC_IDENT)+3;

  401.         ptr[0] = size >> 8;

  402.         ptr[1] = size;

  403.     }

  404. }

  405. 

  406. void mjpeg_picture_header(MpegEncContext *s)

  407. {

  408.     put_marker(&s->pb, SOI);

  409. 

  410.     if (!s->mjpeg_data_only_frames)

  411.     {

  412.     jpeg_put_comments(s);    

  413. 

  414.     if (s->mjpeg_write_tables) jpeg_table_header(s);

  415. 

  416.     put_marker(&s->pb, SOF0);

  417. 

  418.     put_bits(&s->pb, 16, 17);

  419.     put_bits(&s->pb, 8, 8); /* 8 bits/component */

  420.     put_bits(&s->pb, 16, s->height);

  421.     put_bits(&s->pb, 16, s->width);

  422.     put_bits(&s->pb, 8, 3); /* 3 components */

  423.     

  424.     /* Y component */

  425.     put_bits(&s->pb, 8, 1); /* component number */

  426.     put_bits(&s->pb, 4, s->mjpeg_hsample[0]); /* H factor */

  427.     put_bits(&s->pb, 4, s->mjpeg_vsample[0]); /* V factor */

  428.     put_bits(&s->pb, 8, 0); /* select matrix */

  429.     

  430.     /* Cb component */

  431.     put_bits(&s->pb, 8, 2); /* component number */

  432.     put_bits(&s->pb, 4, s->mjpeg_hsample[1]); /* H factor */

  433.     put_bits(&s->pb, 4, s->mjpeg_vsample[1]); /* V factor */

  434. #ifdef TWOMATRIXES

  435.     put_bits(&s->pb, 8, 1); /* select matrix */

  436. #else

  437.     put_bits(&s->pb, 8, 0); /* select matrix */

  438. #endif

  439. 

  440.     /* Cr component */

  441.     put_bits(&s->pb, 8, 3); /* component number */

  442.     put_bits(&s->pb, 4, s->mjpeg_hsample[2]); /* H factor */

  443.     put_bits(&s->pb, 4, s->mjpeg_vsample[2]); /* V factor */

  444. #ifdef TWOMATRIXES

  445.     put_bits(&s->pb, 8, 1); /* select matrix */

  446. #else

  447.     put_bits(&s->pb, 8, 0); /* select matrix */

  448. #endif

  449.     }

  450. 

  451.     /* scan header */

  452.     put_marker(&s->pb, SOS);

  453.     put_bits(&s->pb, 16, 12); /* length */

  454.     put_bits(&s->pb, 8, 3); /* 3 components */

  455.     

  456.     /* Y component */

  457.     put_bits(&s->pb, 8, 1); /* index */

  458.     put_bits(&s->pb, 4, 0); /* DC huffman table index */

  459.     put_bits(&s->pb, 4, 0); /* AC huffman table index */

  460.     

  461.     /* Cb component */

  462.     put_bits(&s->pb, 8, 2); /* index */

  463.     put_bits(&s->pb, 4, 1); /* DC huffman table index */

  464.     put_bits(&s->pb, 4, 1); /* AC huffman table index */

  465.     

  466.     /* Cr component */

  467.     put_bits(&s->pb, 8, 3); /* index */

  468.     put_bits(&s->pb, 4, 1); /* DC huffman table index */

  469.     put_bits(&s->pb, 4, 1); /* AC huffman table index */

  470. 

  471.     put_bits(&s->pb, 8, 0); /* Ss (not used) */

  472.     put_bits(&s->pb, 8, 63); /* Se (not used) */

  473.     put_bits(&s->pb, 8, 0); /* Ah/Al (not used) */

  474. }

  475. 

  476. static void escape_FF(MpegEncContext *s, int start)

  477. {

  478.     int size= get_bit_count(&s->pb) - start*8;

  479.     int i, ff_count;

  480.     uint8_t *buf= s->pb.buf + start;

  481.     int align= (-(size_t)(buf))&3;

  482.     

  483.     assert((size&7) == 0);

  484.     size >>= 3;

  485.     

  486.     ff_count=0;

  487.     for(i=0; i<size && i<align; i++){

  488.         if(buf[i]==0xFF) ff_count++;

  489.     }

  490.     for(; i<size-15; i+=16){

  491.         int acc, v;

  492. 

  493.         v= *(uint32_t*)(&buf[i]);

  494.         acc= (((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;

  495.         v= *(uint32_t*)(&buf[i+4]);

  496.         acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;

  497.         v= *(uint32_t*)(&buf[i+8]);

  498.         acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;

  499.         v= *(uint32_t*)(&buf[i+12]);

  500.         acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;

  501. 

  502.         acc>>=4;

  503.         acc+= (acc>>16);

  504.         acc+= (acc>>8);

  505.         ff_count+= acc&0xFF;

  506.     }

  507.     for(; i<size; i++){

  508.         if(buf[i]==0xFF) ff_count++;

  509.     }

  510. 

  511.     if(ff_count==0) return;

  512.     

  513.     /* skip put bits */

  514.     for(i=0; i<ff_count-3; i+=4)

  515.         put_bits(&s->pb, 32, 0);

  516.     put_bits(&s->pb, (ff_count-i)*8, 0);

  517.     flush_put_bits(&s->pb); 

  518. 

  519.     for(i=size-1; ff_count; i--){

  520.         int v= buf[i];

  521. 

  522.         if(v==0xFF){

  523. //printf("%d %d\n", i, ff_count);

  524.             buf[i+ff_count]= 0;

  525.             ff_count--;

  526.         }

  527. 

  528.         buf[i+ff_count]= v;

  529.     }

  530. }

  531. 

  532. void mjpeg_picture_trailer(MpegEncContext *s)

  533. {

  534.     int pad= (-get_bit_count(&s->pb))&7;

  535.     

  536.     put_bits(&s->pb, pad,0xFF>>(8-pad));

  537.     flush_put_bits(&s->pb);

  538. 

  539.     assert((s->header_bits&7)==0);

  540.     

  541.     escape_FF(s, s->header_bits>>3);

  542. 

  543.     put_marker(&s->pb, EOI);

  544. }

  545. 

  546. static inline void mjpeg_encode_dc(MpegEncContext *s, int val,

  547. 				   uint8_t *huff_size, uint16_t *huff_code)

  548. {

  549.     int mant, nbits;

  550. 

  551.     if (val == 0) {

  552.         put_bits(&s->pb, huff_size[0], huff_code[0]);

  553.     } else {

  554.         mant = val;

  555.         if (val < 0) {

  556.             val = -val;

  557.             mant--;

  558.         }

  559.         

  560.         nbits= av_log2(val) + 1;

  561.             

  562.         put_bits(&s->pb, huff_size[nbits], huff_code[nbits]);

  563.         

  564.         put_bits(&s->pb, nbits, mant & ((1 << nbits) - 1));

  565.     }

  566. }

  567. 

  568. static void encode_block(MpegEncContext *s, DCTELEM *block, int n)

  569. {

  570.     int mant, nbits, code, i, j;

  571.     int component, dc, run, last_index, val;

  572.     MJpegContext *m = s->mjpeg_ctx;

  573.     uint8_t *huff_size_ac;

  574.     uint16_t *huff_code_ac;

  575.     

  576.     /* DC coef */

  577.     component = (n <= 3 ? 0 : n - 4 + 1);

  578.     dc = block[0]; /* overflow is impossible */

  579.     val = dc - s->last_dc[component];

  580.     if (n < 4) {

  581.         mjpeg_encode_dc(s, val, m->huff_size_dc_luminance, m->huff_code_dc_luminance);

  582.         huff_size_ac = m->huff_size_ac_luminance;

  583.         huff_code_ac = m->huff_code_ac_luminance;

  584.     } else {

  585.         mjpeg_encode_dc(s, val, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);

  586.         huff_size_ac = m->huff_size_ac_chrominance;

  587.         huff_code_ac = m->huff_code_ac_chrominance;

  588.     }

  589.     s->last_dc[component] = dc;

  590.     

  591.     /* AC coefs */

  592.     

  593.     run = 0;

  594.     last_index = s->block_last_index[n];

  595.     for(i=1;i<=last_index;i++) {

  596.         j = s->intra_scantable.permutated[i];

  597.         val = block[j];

  598.         if (val == 0) {

  599.             run++;

  600.         } else {

  601.             while (run >= 16) {

  602.                 put_bits(&s->pb, huff_size_ac[0xf0], huff_code_ac[0xf0]);

  603.                 run -= 16;

  604.             }

  605.             mant = val;

  606.             if (val < 0) {

  607.                 val = -val;

  608.                 mant--;

  609.             }

  610.             

  611.             nbits= av_log2(val) + 1;

  612.             code = (run << 4) | nbits;

  613. 

  614.             put_bits(&s->pb, huff_size_ac[code], huff_code_ac[code]);

  615.         

  616.             put_bits(&s->pb, nbits, mant & ((1 << nbits) - 1));

  617.             run = 0;

  618.         }

  619.     }

  620. 

  621.     /* output EOB only if not already 64 values */

  622.     if (last_index < 63 || run != 0)

  623.         put_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]);

  624. }

  625. 

  626. void mjpeg_encode_mb(MpegEncContext *s, 

  627.                      DCTELEM block[6][64])

  628. {

  629.     int i;

  630.     for(i=0;i<6;i++) {

  631.         encode_block(s, block[i], i);

  632.     }

  633. }

  634. 

  635. /******************************************/

  636. /* decoding */

  637. 

  638. #define MAX_COMPONENTS 4

  639. 

  640. typedef struct MJpegDecodeContext {

  641.     AVCodecContext *avctx;

  642.     GetBitContext gb;

  643.     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */

  644. 

  645.     int start_code; /* current start code */

  646.     int buffer_size;

  647.     uint8_t *buffer;

  648. 

  649.     int16_t quant_matrixes[4][64];

  650.     VLC vlcs[2][4];

  651. 

  652.     int org_width, org_height;  /* size given at codec init */

  653.     int first_picture;    /* true if decoding first picture */

  654.     int interlaced;     /* true if interlaced */

  655.     int bottom_field;   /* true if bottom field */

  656. 

  657.     int width, height;

  658.     int nb_components;

  659.     int component_id[MAX_COMPONENTS];

  660.     int h_count[MAX_COMPONENTS]; /* horizontal and vertical count for each component */

  661.     int v_count[MAX_COMPONENTS];

  662.     int h_max, v_max; /* maximum h and v counts */

  663.     int quant_index[4];   /* quant table index for each component */

  664.     int last_dc[MAX_COMPONENTS]; /* last DEQUANTIZED dc (XXX: am I right to do that ?) */

  665.     uint8_t *current_picture[MAX_COMPONENTS]; /* picture structure */

  666.     int linesize[MAX_COMPONENTS];

  667.     DCTELEM block[64] __align8;

  668.     ScanTable scantable;

  669.     void (*idct_put)(uint8_t *dest/*align 8*/, int line_size, DCTELEM *block/*align 16*/);

  670. 

  671.     int restart_interval;

  672.     int restart_count;

  673. 

  674.     int buggy_avid;

  675.     int interlace_polarity;

  676. } MJpegDecodeContext;

  677. 

  678. static int mjpeg_decode_dht(MJpegDecodeContext *s);

  679. 

  680. static void build_vlc(VLC *vlc, const uint8_t *bits_table, const uint8_t *val_table, 

  681.                       int nb_codes)

  682. {

  683.     uint8_t huff_size[256];

  684.     uint16_t huff_code[256];

  685. 

  686.     memset(huff_size, 0, sizeof(huff_size));

  687.     build_huffman_codes(huff_size, huff_code, bits_table, val_table);

  688.     

  689.     init_vlc(vlc, 9, nb_codes, huff_size, 1, 1, huff_code, 2, 2);

  690. }

  691. 

  692. static int mjpeg_decode_init(AVCodecContext *avctx)

  693. {

  694.     MJpegDecodeContext *s = avctx->priv_data;

  695.     MpegEncContext s2;

  696. 

  697.     s->avctx = avctx;

  698. 

  699.     /* ugly way to get the idct & scantable FIXME */

  700.     memset(&s2, 0, sizeof(MpegEncContext));

  701.     s2.flags= avctx->flags;

  702.     s2.avctx= avctx;

  703. //    s2->out_format = FMT_MJPEG;

  704.     s2.width = 8;

  705.     s2.height = 8;

  706.     if (MPV_common_init(&s2) < 0)

  707.        return -1;

  708.     s->scantable= s2.intra_scantable;

  709.     s->idct_put= s2.dsp.idct_put;

  710.     MPV_common_end(&s2);

  711. 

  712.     s->mpeg_enc_ctx_allocated = 0;

  713.     s->buffer_size = 102400; /* smaller buffer should be enough,

  714. 				but photojpg files could ahive bigger sizes */

  715.     s->buffer = av_malloc(s->buffer_size);

  716.     if (!s->buffer)

  717. 	return -1;

  718.     s->start_code = -1;

  719.     s->first_picture = 1;

  720.     s->org_width = avctx->width;

  721.     s->org_height = avctx->height;

  722.     

  723.     build_vlc(&s->vlcs[0][0], bits_dc_luminance, val_dc_luminance, 12);

  724.     build_vlc(&s->vlcs[0][1], bits_dc_chrominance, val_dc_chrominance, 12);

  725.     build_vlc(&s->vlcs[1][0], bits_ac_luminance, val_ac_luminance, 251);

  726.     build_vlc(&s->vlcs[1][1], bits_ac_chrominance, val_ac_chrominance, 251);

  727. 

  728.     if (avctx->flags & CODEC_FLAG_EXTERN_HUFF)

  729.     {

  730. 	printf("mjpeg: using external huffman table\n");

  731. 	init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size*8);

  732. 	mjpeg_decode_dht(s);

  733. 	/* should check for error - but dunno */

  734.     }

  735. 

  736.     return 0;

  737. }

  738. 

  739. /* quantize tables */

  740. static int mjpeg_decode_dqt(MJpegDecodeContext *s)

  741. {

  742.     int len, index, i, j;

  743.     

  744.     len = get_bits(&s->gb, 16) - 2;

  745. 

  746.     while (len >= 65) {

  747.         /* only 8 bit precision handled */

  748.         if (get_bits(&s->gb, 4) != 0)

  749. 	{

  750. 	    dprintf("dqt: 16bit precision\n");

  751.             return -1;

  752. 	}

  753.         index = get_bits(&s->gb, 4);

  754.         if (index >= 4)

  755.             return -1;

  756.         dprintf("index=%d\n", index);

  757.         /* read quant table */

  758.         for(i=0;i<64;i++) {

  759.             j = s->scantable.permutated[i];

  760. 	    s->quant_matrixes[index][j] = get_bits(&s->gb, 8);

  761.         }

  762.         len -= 65;

  763.     }

  764.     

  765.     return 0;

  766. }

  767. 

  768. /* decode huffman tables and build VLC decoders */

  769. static int mjpeg_decode_dht(MJpegDecodeContext *s)

  770. {

  771.     int len, index, i, class, n, v, code_max;

  772.     uint8_t bits_table[17];

  773.     uint8_t val_table[256];

  774.     

  775.     len = get_bits(&s->gb, 16) - 2;

  776. 

  777.     while (len > 0) {

  778.         if (len < 17)

  779.             return -1;

  780.         class = get_bits(&s->gb, 4);

  781.         if (class >= 2)

  782.             return -1;

  783.         index = get_bits(&s->gb, 4);

  784.         if (index >= 4)

  785.             return -1;

  786.         n = 0;

  787.         for(i=1;i<=16;i++) {

  788.             bits_table[i] = get_bits(&s->gb, 8);

  789.             n += bits_table[i];

  790.         }

  791.         len -= 17;

  792.         if (len < n || n > 256)

  793.             return -1;

  794. 

  795.         code_max = 0;

  796.         for(i=0;i<n;i++) {

  797.             v = get_bits(&s->gb, 8);

  798.             if (v > code_max)

  799.                 code_max = v;

  800.             val_table[i] = v;

  801.         }

  802.         len -= n;

  803. 

  804.         /* build VLC and flush previous vlc if present */

  805.         free_vlc(&s->vlcs[class][index]);

  806.         dprintf("class=%d index=%d nb_codes=%d\n",

  807.                class, index, code_max + 1);

  808.         build_vlc(&s->vlcs[class][index], bits_table, val_table, code_max + 1);

  809.     }

  810.     return 0;

  811. }

  812. 

  813. static int mjpeg_decode_sof0(MJpegDecodeContext *s)

  814. {

  815.     int len, nb_components, i, width, height;

  816. 

  817.     /* XXX: verify len field validity */

  818.     len = get_bits(&s->gb, 16);

  819.     /* only 8 bits/component accepted */

  820.     if (get_bits(&s->gb, 8) != 8)

  821.         return -1;

  822.     height = get_bits(&s->gb, 16);

  823.     width = get_bits(&s->gb, 16);

  824.     dprintf("sof0: picture: %dx%d\n", width, height);

  825. 

  826.     nb_components = get_bits(&s->gb, 8);

  827.     if (nb_components <= 0 ||

  828.         nb_components > MAX_COMPONENTS)

  829.         return -1;

  830.     s->nb_components = nb_components;

  831.     s->h_max = 1;

  832.     s->v_max = 1;

  833.     for(i=0;i<nb_components;i++) {

  834.         /* component id */

  835.         s->component_id[i] = get_bits(&s->gb, 8) - 1;

  836.         s->h_count[i] = get_bits(&s->gb, 4);

  837.         s->v_count[i] = get_bits(&s->gb, 4);

  838.         /* compute hmax and vmax (only used in interleaved case) */

  839.         if (s->h_count[i] > s->h_max)

  840.             s->h_max = s->h_count[i];

  841.         if (s->v_count[i] > s->v_max)

  842.             s->v_max = s->v_count[i];

  843.         s->quant_index[i] = get_bits(&s->gb, 8);

  844.         if (s->quant_index[i] >= 4)

  845.             return -1;

  846.         dprintf("component %d %d:%d id: %d quant:%d\n", i, s->h_count[i],

  847. 	    s->v_count[i], s->component_id[i], s->quant_index[i]);

  848.     }

  849. 

  850.     /* if different size, realloc/alloc picture */

  851.     /* XXX: also check h_count and v_count */

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

  853.         for(i=0;i<MAX_COMPONENTS;i++)

  854.             av_freep(&s->current_picture[i]);

  855.         s->width = width;

  856.         s->height = height;

  857.         /* test interlaced mode */

  858.         if (s->first_picture &&

  859.             s->org_height != 0 &&

  860.             s->height < ((s->org_height * 3) / 4)) {

  861.             s->interlaced = 1;

  862. //	    s->bottom_field = (s->interlace_polarity) ? 1 : 0;

  863. 	    s->bottom_field = 0;

  864.         }

  865. 

  866.         for(i=0;i<nb_components;i++) {

  867.             int w, h;

  868.             w = (s->width  + 8 * s->h_max - 1) / (8 * s->h_max);

  869.             h = (s->height + 8 * s->v_max - 1) / (8 * s->v_max);

  870.             w = w * 8 * s->h_count[i];

  871.             h = h * 8 * s->v_count[i];

  872.             if (s->interlaced)

  873.                 w *= 2;

  874.             s->linesize[i] = w;

  875.             s->current_picture[i] = av_mallocz(w * h);

  876. 	    if (!s->current_picture[i])

  877. 	    {

  878. 		dprintf("error: no picture buffers allocated\n");

  879. 		return -1;

  880. 	    }

  881.         }

  882.         s->first_picture = 0;

  883.     }

  884. 

  885.     if (len != (8+(3*nb_components)))

  886.     {

  887. 	dprintf("decode_sof0: error, len(%d) mismatch\n", len);

  888.     }

  889.     

  890.     return 0;

  891. }

  892. 

  893. static inline int mjpeg_decode_dc(MJpegDecodeContext *s, int dc_index)

  894. {

  895.     int code;

  896.     code = get_vlc2(&s->gb, s->vlcs[0][dc_index].table, 9, 2);

  897.     if (code < 0)

  898.     {

  899. 	dprintf("mjpeg_decode_dc: bad vlc: %d:%d (%p)\n", 0, dc_index,

  900.                 &s->vlcs[0][dc_index]);

  901.         return 0xffff;

  902.     }

  903. 

  904.     if(code)

  905.         return get_xbits(&s->gb, code);

  906.     else

  907.         return 0;

  908. }

  909. 

  910. /* decode block and dequantize */

  911. static int decode_block(MJpegDecodeContext *s, DCTELEM *block, 

  912.                         int component, int dc_index, int ac_index, int quant_index)

  913. {

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

  915.     VLC *ac_vlc;

  916.     int16_t *quant_matrix;

  917. 

  918.     /* DC coef */

  919.     val = mjpeg_decode_dc(s, dc_index);

  920.     if (val == 0xffff) {

  921.         dprintf("error dc\n");

  922.         return -1;

  923.     }

  924.     quant_matrix = s->quant_matrixes[quant_index];

  925.     val = val * quant_matrix[0] + s->last_dc[component];

  926.     s->last_dc[component] = val;

  927.     block[0] = val;

  928.     /* AC coefs */

  929.     ac_vlc = &s->vlcs[1][ac_index];

  930.     i = 1;

  931.     for(;;) {

  932. 	code = get_vlc2(&s->gb, s->vlcs[1][ac_index].table, 9, 2);

  933. 

  934.         if (code < 0) {

  935.             dprintf("error ac\n");

  936.             return -1;

  937.         }

  938.         /* EOB */

  939.         if (code == 0)

  940.             break;

  941.         if (code == 0xf0) {

  942.             i += 16;

  943.         } else {

  944.             level = get_xbits(&s->gb, code & 0xf);

  945.             i += code >> 4;

  946.             if (i >= 64) {

  947.                 dprintf("error count: %d\n", i);

  948.                 return -1;

  949.             }

  950.             j = s->scantable.permutated[i];

  951.             block[j] = level * quant_matrix[j];

  952.             i++;

  953.             if (i >= 64)

  954.                 break;

  955.         }

  956.     }

  957.     return 0;

  958. }

  959. 

  960. static int mjpeg_decode_sos(MJpegDecodeContext *s)

  961. {

  962.     int len, nb_components, i, j, n, h, v, ret;

  963.     int mb_width, mb_height, mb_x, mb_y, vmax, hmax, index, id;

  964.     int comp_index[4];

  965.     int dc_index[4];

  966.     int ac_index[4];

  967.     int nb_blocks[4];

  968.     int h_count[4];

  969.     int v_count[4];

  970.     

  971.     /* XXX: verify len field validity */

  972.     len = get_bits(&s->gb, 16);

  973.     nb_components = get_bits(&s->gb, 8);

  974.     if (len != 6+2*nb_components)

  975.     {

  976. 	dprintf("decode_sos: invalid len (%d)\n", len);

  977. 	return -1;

  978.     }

  979.     /* XXX: only interleaved scan accepted */

  980.     if (nb_components != 3)

  981.     {

  982. 	dprintf("decode_sos: components(%d) mismatch\n", nb_components);

  983.         return -1;

  984.     }

  985.     vmax = 0;

  986.     hmax = 0;

  987.     for(i=0;i<nb_components;i++) {

  988.         id = get_bits(&s->gb, 8) - 1;

  989. 	dprintf("component: %d\n", id);

  990.         /* find component index */

  991.         for(index=0;index<s->nb_components;index++)

  992.             if (id == s->component_id[index])

  993.                 break;

  994.         if (index == s->nb_components)

  995. 	{

  996. 	    dprintf("decode_sos: index(%d) out of components\n", index);

  997.             return -1;

  998. 	}

  999. 

  1000.         comp_index[i] = index;

  1001.         nb_blocks[i] = s->h_count[index] * s->v_count[index];

  1002.         h_count[i] = s->h_count[index];

  1003.         v_count[i] = s->v_count[index];

  1004. 

  1005.         dc_index[i] = get_bits(&s->gb, 4);

  1006.         ac_index[i] = get_bits(&s->gb, 4);

  1007. 

  1008. 	if (dc_index[i] < 0 || ac_index[i] < 0 ||

  1009. 	    dc_index[i] >= 4 || ac_index[i] >= 4)

  1010. 	    goto out_of_range;

  1011. 	switch(s->start_code)

  1012. 	{

  1013. 	    case SOF0:

  1014. 		if (dc_index[i] > 1 || ac_index[i] > 1)

  1015. 		    goto out_of_range;

  1016. 		break;

  1017. 	    case SOF1:

  1018. 	    case SOF2:

  1019. 		if (dc_index[i] > 3 || ac_index[i] > 3)

  1020. 		    goto out_of_range;

  1021. 		break;

  1022. 	    case SOF3:

  1023. 		if (dc_index[i] > 3 || ac_index[i] != 0)

  1024. 		    goto out_of_range;

  1025. 		break;	

  1026. 	}

  1027.     }

  1028.     skip_bits(&s->gb, 8); /* Ss */

  1029.     skip_bits(&s->gb, 8); /* Se */

  1030.     skip_bits(&s->gb, 8); /* Ah and Al (each are 4 bits) */

  1031. 

  1032.     for(i=0;i<nb_components;i++) 

  1033.         s->last_dc[i] = 1024;

  1034. 

  1035.     if (nb_components > 1) {

  1036.         /* interleaved stream */

  1037.         mb_width = (s->width + s->h_max * 8 - 1) / (s->h_max * 8);

  1038.         mb_height = (s->height + s->v_max * 8 - 1) / (s->v_max * 8);

  1039.     } else {

  1040.         h = s->h_max / s->h_count[comp_index[0]];

  1041.         v = s->v_max / s->v_count[comp_index[0]];

  1042.         mb_width = (s->width + h * 8 - 1) / (h * 8);

  1043.         mb_height = (s->height + v * 8 - 1) / (v * 8);

  1044.         nb_blocks[0] = 1;

  1045.         h_count[0] = 1;

  1046.         v_count[0] = 1;

  1047.     }

  1048.     

  1049.     for(mb_y = 0; mb_y < mb_height; mb_y++) {

  1050.         for(mb_x = 0; mb_x < mb_width; mb_x++) {

  1051.             for(i=0;i<nb_components;i++) {

  1052.                 uint8_t *ptr;

  1053.                 int x, y, c;

  1054.                 n = nb_blocks[i];

  1055.                 c = comp_index[i];

  1056.                 h = h_count[i];

  1057.                 v = v_count[i];

  1058.                 x = 0;

  1059.                 y = 0;

  1060. 		if (s->restart_interval && !s->restart_count)

  1061. 		    s->restart_count = s->restart_interval;

  1062.                 for(j=0;j<n;j++) {

  1063.                     memset(s->block, 0, sizeof(s->block));

  1064.                     if (decode_block(s, s->block, i, 

  1065.                                      dc_index[i], ac_index[i], 

  1066.                                      s->quant_index[c]) < 0) {

  1067.                         dprintf("error y=%d x=%d\n", mb_y, mb_x);

  1068.                         ret = -1;

  1069.                         goto the_end;

  1070.                     }

  1071. //		    dprintf("mb: %d %d processed\n", mb_y, mb_x);

  1072.                     ptr = s->current_picture[c] + 

  1073.                         (s->linesize[c] * (v * mb_y + y) * 8) + 

  1074.                         (h * mb_x + x) * 8;

  1075.                     if (s->interlaced && s->bottom_field)

  1076.                         ptr += s->linesize[c] >> 1;

  1077.                     s->idct_put(ptr, s->linesize[c], s->block);

  1078.                     if (++x == h) {

  1079.                         x = 0;

  1080.                         y++;

  1081.                     }

  1082.                 }

  1083.             }

  1084. 	    /* (< 1350) buggy workaround for Spectralfan.mov, should be fixed */

  1085.             if (s->restart_interval && (s->restart_interval < 1350) &&

  1086. 		!--s->restart_count) {

  1087.                 align_get_bits(&s->gb);

  1088.                 skip_bits(&s->gb, 16); /* skip RSTn */

  1089.                 for (j=0; j<nb_components; j++) /* reset dc */

  1090.                     s->last_dc[j] = 1024;

  1091.             }

  1092.         }

  1093.     }

  1094.     ret = 0;

  1095.  the_end:

  1096.     emms_c();

  1097.     return ret;

  1098.  out_of_range:

  1099.     dprintf("decode_sos: ac/dc index out of range\n");

  1100.     return -1;

  1101. }

  1102. 

  1103. static int mjpeg_decode_dri(MJpegDecodeContext *s)

  1104. {

  1105.     if (get_bits(&s->gb, 16) != 4)

  1106. 	return -1;

  1107.     s->restart_interval = get_bits(&s->gb, 16);

  1108.     dprintf("restart interval: %d\n", s->restart_interval);

  1109. 

  1110.     return 0;

  1111. }

  1112. 

  1113. static int mjpeg_decode_app(MJpegDecodeContext *s)

  1114. {

  1115.     int len, id;

  1116. 

  1117.     /* XXX: verify len field validity */

  1118.     len = get_bits(&s->gb, 16);

  1119.     if (len < 5)

  1120. 	return -1;

  1121. 

  1122.     id = (get_bits(&s->gb, 16) << 16) | get_bits(&s->gb, 16);

  1123.     id = be2me_32(id);

  1124.     len -= 6;

  1125. 

  1126.     /* buggy AVID, it puts EOI only at every 10th frame */

  1127.     /* also this fourcc is used by non-avid files too, it holds some

  1128.        informations, but it's always present in AVID creates files */

  1129.     if (id == ff_get_fourcc("AVI1"))

  1130.     {

  1131. 	/* structure:

  1132. 	    4bytes	AVI1

  1133. 	    1bytes	polarity

  1134. 	    1bytes	always zero

  1135. 	    4bytes	field_size

  1136. 	    4bytes	field_size_less_padding

  1137. 	*/

  1138.     	s->buggy_avid = 1;

  1139. //	if (s->first_picture)

  1140. //	    printf("mjpeg: workarounding buggy AVID\n");

  1141. 	s->interlace_polarity = get_bits(&s->gb, 8);

  1142. #if 0

  1143. 	skip_bits(&s->gb, 8);

  1144. 	skip_bits(&s->gb, 32);

  1145. 	skip_bits(&s->gb, 32);

  1146. 	len -= 10;

  1147. #endif

  1148. //	if (s->interlace_polarity)

  1149. //	    printf("mjpeg: interlace polarity: %d\n", s->interlace_polarity);

  1150. 	goto out;

  1151.     }

  1152.     

  1153. //    len -= 2;

  1154.     

  1155.     if (id == ff_get_fourcc("JFIF"))

  1156.     {

  1157. 	int t_w, t_h;

  1158. 	skip_bits(&s->gb, 8); /* the trailing zero-byte */

  1159. 	printf("mjpeg: JFIF header found (version: %x.%x)\n",

  1160. 	    get_bits(&s->gb, 8), get_bits(&s->gb, 8));

  1161. 	if (get_bits(&s->gb, 8) == 0)

  1162. 	{

  1163. 	    int x_density, y_density; 

  1164. 	    x_density = get_bits(&s->gb, 16);

  1165. 	    y_density = get_bits(&s->gb, 16);

  1166. 

  1167. 	    dprintf("x/y density: %d (%f), %d (%f)\n", x_density,

  1168. 		(float)x_density, y_density, (float)y_density);

  1169. #if 0

  1170.             //MN: needs to be checked

  1171.             if(x_density)

  1172. //                s->avctx->aspect_ratio= s->width*y_density/((float)s->height*x_density);

  1173. 		s->avctx->aspect_ratio = (float)x_density/y_density;

  1174. 		/* it's better, but every JFIF I have seen stores 1:1 */

  1175.             else

  1176.                 s->avctx->aspect_ratio= 0.0;

  1177. #endif

  1178. 	}

  1179. 	else

  1180. 	{

  1181. 	    skip_bits(&s->gb, 16);

  1182. 	    skip_bits(&s->gb, 16);

  1183. 	}

  1184. 

  1185. 	t_w = get_bits(&s->gb, 8);

  1186. 	t_h = get_bits(&s->gb, 8);

  1187. 	if (t_w && t_h)

  1188. 	{

  1189. 	    /* skip thumbnail */

  1190. 	    if (len-10-(t_w*t_h*3) > 0)

  1191. 		len -= t_w*t_h*3;

  1192. 	}

  1193. 	len -= 10;

  1194. 	goto out;

  1195.     }

  1196.     

  1197.     if (id == ff_get_fourcc("Adob") && (get_bits(&s->gb, 8) == 'e'))

  1198.     {

  1199. 	printf("mjpeg: Adobe header found\n");

  1200. 	skip_bits(&s->gb, 16); /* version */

  1201. 	skip_bits(&s->gb, 16); /* flags0 */

  1202. 	skip_bits(&s->gb, 16); /* flags1 */

  1203. 	skip_bits(&s->gb, 8); /* transform */

  1204. 	len -= 7;

  1205. 	goto out;

  1206.     }

  1207.     

  1208.     /* Apple MJPEG-A */

  1209.     if ((s->start_code == APP1) && (len > (0x28 - 8)))

  1210.     {

  1211. 	id = (get_bits(&s->gb, 16) << 16) | get_bits(&s->gb, 16);

  1212. 	id = be2me_32(id);

  1213. 	len -= 4;

  1214. 	if (id == ff_get_fourcc("mjpg")) /* Apple MJPEG-A */

  1215. 	{

  1216. #if 0

  1217. 	    skip_bits(&s->gb, 32); /* field size */

  1218. 	    skip_bits(&s->gb, 32); /* pad field size */

  1219. 	    skip_bits(&s->gb, 32); /* next off */

  1220. 	    skip_bits(&s->gb, 32); /* quant off */

  1221. 	    skip_bits(&s->gb, 32); /* huff off */

  1222. 	    skip_bits(&s->gb, 32); /* image off */

  1223. 	    skip_bits(&s->gb, 32); /* scan off */

  1224. 	    skip_bits(&s->gb, 32); /* data off */

  1225. #endif

  1226. 	    if (s->first_picture)

  1227. 		printf("mjpeg: Apple MJPEG-A header found\n");

  1228. 	}

  1229.     }

  1230. 

  1231. out:

  1232.     /* slow but needed for extreme adobe jpegs */

  1233.     if (len < 0)

  1234. 	printf("mjpeg: error, decode_app parser read over the end\n");

  1235.     while(--len > 0)

  1236. 	skip_bits(&s->gb, 8);

  1237. 

  1238.     return 0;

  1239. }

  1240. 

  1241. static int mjpeg_decode_com(MJpegDecodeContext *s)

  1242. {

  1243.     /* XXX: verify len field validity */

  1244.     unsigned int len = get_bits(&s->gb, 16);

  1245.     if (len >= 2 && len < 32768) {

  1246. 	/* XXX: any better upper bound */

  1247. 	uint8_t *cbuf = av_malloc(len - 1);

  1248. 	if (cbuf) {

  1249. 	    int i;

  1250. 	    for (i = 0; i < len - 2; i++)

  1251. 		cbuf[i] = get_bits(&s->gb, 8);

  1252. 	    if (i > 0 && cbuf[i-1] == '\n')

  1253. 		cbuf[i-1] = 0;

  1254. 	    else

  1255. 		cbuf[i] = 0;

  1256. 

  1257. 	    printf("mjpeg comment: '%s'\n", cbuf);

  1258. 

  1259. 	    /* buggy avid, it puts EOI only at every 10th frame */

  1260. 	    if (!strcmp(cbuf, "AVID"))

  1261. 	    {

  1262. 		s->buggy_avid = 1;

  1263. 		//	if (s->first_picture)

  1264. 		//	    printf("mjpeg: workarounding buggy AVID\n");

  1265. 	    }

  1266. 

  1267. 	    av_free(cbuf);

  1268. 	}

  1269.     }

  1270. 

  1271.     return 0;

  1272. }

  1273. 

  1274. #if 0

  1275. static int valid_marker_list[] =

  1276. {

  1277.         /* 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f */

  1278. /* 0 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1279. /* 1 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1280. /* 2 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1281. /* 3 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1282. /* 4 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1283. /* 5 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1284. /* 6 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1285. /* 7 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1286. /* 8 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1287. /* 9 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1288. /* a */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1289. /* b */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  1290. /* c */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  1291. /* d */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  1292. /* e */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  1293. /* f */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,

  1294. }

  1295. #endif

  1296. 

  1297. /* return the 8 bit start code value and update the search

  1298.    state. Return -1 if no start code found */

  1299. static int find_marker(uint8_t **pbuf_ptr, uint8_t *buf_end)

  1300. {

  1301.     uint8_t *buf_ptr;

  1302.     unsigned int v, v2;

  1303.     int val;

  1304. #ifdef DEBUG

  1305.     int skipped=0;

  1306. #endif

  1307. 

  1308.     buf_ptr = *pbuf_ptr;

  1309.     while (buf_ptr < buf_end) {

  1310.         v = *buf_ptr++;

  1311. 	v2 = *buf_ptr;

  1312.         if ((v == 0xff) && (v2 >= 0xc0) && (v2 <= 0xfe)) {

  1313. 	    val = *buf_ptr++;

  1314. 	    goto found;

  1315.         }

  1316. #ifdef DEBUG

  1317. 	skipped++;

  1318. #endif

  1319.     }

  1320.     val = -1;

  1321. found:

  1322. #ifdef DEBUG

  1323.     dprintf("find_marker skipped %d bytes\n", skipped);

  1324. #endif

  1325.     *pbuf_ptr = buf_ptr;

  1326.     return val;

  1327. }

  1328. 

  1329. static int mjpeg_decode_frame(AVCodecContext *avctx, 

  1330.                               void *data, int *data_size,

  1331.                               uint8_t *buf, int buf_size)

  1332. {

  1333.     MJpegDecodeContext *s = avctx->priv_data;

  1334.     uint8_t *buf_end, *buf_ptr;

  1335.     int i, start_code;

  1336.     AVPicture *picture = data;

  1337. 

  1338.     *data_size = 0;

  1339. 

  1340.     /* no supplementary picture */

  1341.     if (buf_size == 0)

  1342.         return 0;

  1343. 

  1344.     buf_ptr = buf;

  1345.     buf_end = buf + buf_size;

  1346.     while (buf_ptr < buf_end) {

  1347.         /* find start next marker */

  1348.         start_code = find_marker(&buf_ptr, buf_end);

  1349. 	{

  1350. 	    /* EOF */

  1351.             if (start_code < 0) {

  1352. 		goto the_end;

  1353.             } else {

  1354.                 dprintf("marker=%x avail_size_in_buf=%d\n", start_code, buf_end - buf_ptr);

  1355. 		

  1356. 		if ((buf_end - buf_ptr) > s->buffer_size)

  1357. 		{

  1358. 		    av_free(s->buffer);

  1359. 		    s->buffer_size = buf_end-buf_ptr;

  1360. 		    s->buffer = av_malloc(s->buffer_size);

  1361. 		    dprintf("buffer too small, expanding to %d bytes\n",

  1362. 			s->buffer_size);

  1363. 		}

  1364. 		

  1365. 		/* unescape buffer of SOS */

  1366. 		if (start_code == SOS)

  1367. 		{

  1368. 		    uint8_t *src = buf_ptr;

  1369. 		    uint8_t *dst = s->buffer;

  1370. 

  1371. 		    while (src<buf_end)

  1372. 		    {

  1373. 			uint8_t x = *(src++);

  1374. 

  1375. 			*(dst++) = x;

  1376. 			if (x == 0xff)

  1377. 			{

  1378. 			    while(*src == 0xff) src++;

  1379. 

  1380. 			    x = *(src++);

  1381. 			    if (x >= 0xd0 && x <= 0xd7)

  1382. 				*(dst++) = x;

  1383. 			    else if (x)

  1384. 				break;

  1385. 			}

  1386. 		    }

  1387. 		    init_get_bits(&s->gb, s->buffer, (dst - s->buffer)*8);

  1388. 		    

  1389. 		    dprintf("escaping removed %d bytes\n",

  1390. 			(buf_end - buf_ptr) - (dst - s->buffer));

  1391. 		}

  1392. 		else

  1393. 		    init_get_bits(&s->gb, buf_ptr, (buf_end - buf_ptr)*8);

  1394. 		

  1395. 		s->start_code = start_code;

  1396. 

  1397. 		/* process markers */

  1398. 		if (start_code >= 0xd0 && start_code <= 0xd7) {

  1399. 		    dprintf("restart marker: %d\n", start_code&0x0f);

  1400. 		} else if (s->first_picture) {

  1401. 		    /* APP fields */

  1402. 		    if (start_code >= 0xe0 && start_code <= 0xef)

  1403. 			mjpeg_decode_app(s);

  1404. 		    /* Comment */

  1405. 		    else if (start_code == COM)

  1406. 			mjpeg_decode_com(s);

  1407. 		}

  1408. 

  1409.                 switch(start_code) {

  1410.                 case SOI:

  1411. 		    s->restart_interval = 0;

  1412.                     /* nothing to do on SOI */

  1413.                     break;

  1414.                 case DQT:

  1415.                     mjpeg_decode_dqt(s);

  1416.                     break;

  1417.                 case DHT:

  1418.                     mjpeg_decode_dht(s);

  1419.                     break;

  1420.                 case SOF0:

  1421.                     if (mjpeg_decode_sof0(s) < 0)

  1422. 			return -1;

  1423.                     break;

  1424. 		case EOI:

  1425. eoi_parser:

  1426. 		    {

  1427.                         if (s->interlaced) {

  1428.                             s->bottom_field ^= 1;

  1429.                             /* if not bottom field, do not output image yet */

  1430.                             if (s->bottom_field)

  1431.                                 goto not_the_end;

  1432.                         }

  1433.                         for(i=0;i<3;i++) {

  1434.                             picture->data[i] = s->current_picture[i];

  1435. 			    picture->linesize[i] = (s->interlaced) ?

  1436. 				s->linesize[i] >> 1 : s->linesize[i];

  1437.                         }

  1438.                         *data_size = sizeof(AVPicture);

  1439.                         avctx->height = s->height;

  1440.                         if (s->interlaced)

  1441.                             avctx->height *= 2;

  1442.                         avctx->width = s->width;

  1443.                         /* XXX: not complete test ! */

  1444.                         switch((s->h_count[0] << 4) | s->v_count[0]) {

  1445.                         case 0x11:

  1446.                             avctx->pix_fmt = PIX_FMT_YUV444P;

  1447.                             break;

  1448.                         case 0x21:

  1449.                             avctx->pix_fmt = PIX_FMT_YUV422P;

  1450.                             break;

  1451.                         default:

  1452.                         case 0x22:

  1453.                             avctx->pix_fmt = PIX_FMT_YUV420P;

  1454.                             break;

  1455.                         }

  1456.                         /* dummy quality */

  1457.                         /* XXX: infer it with matrix */

  1458. //                    	avctx->quality = 3; 

  1459.                         goto the_end;

  1460.                     }

  1461. 		    break;

  1462.                 case SOS:

  1463.                     mjpeg_decode_sos(s);

  1464. 		    /* buggy avid puts EOI every 10-20th frame */

  1465. 		    /* if restart period is over process EOI */

  1466. 		    if ((s->buggy_avid && !s->interlaced) || s->restart_interval)

  1467. 			goto eoi_parser;

  1468.                     break;

  1469. 		case DRI:

  1470. 		    mjpeg_decode_dri(s);

  1471. 		    break;

  1472. 		case SOF1:

  1473. 		case SOF2:

  1474. 		case SOF3:

  1475. 		case SOF5:

  1476. 		case SOF6:

  1477. 		case SOF7:

  1478. 		case SOF9:

  1479. 		case SOF10:

  1480. 		case SOF11:

  1481. 		case SOF13:

  1482. 		case SOF14:

  1483. 		case SOF15:

  1484. 		case JPG:

  1485. 		    printf("mjpeg: unsupported coding type (%x)\n", start_code);

  1486. 		    break;

  1487. //		default:

  1488. //		    printf("mjpeg: unsupported marker (%x)\n", start_code);

  1489. //		    break;

  1490.                 }

  1491. 

  1492. not_the_end:

  1493. 		/* eof process start code */

  1494. 		buf_ptr += (get_bits_count(&s->gb)+7)/8;

  1495. 		dprintf("marker parser used %d bytes (%d bits)\n",

  1496. 		    (get_bits_count(&s->gb)+7)/8, get_bits_count(&s->gb));

  1497.             }

  1498.         }

  1499.     }

  1500. the_end:

  1501.     dprintf("mjpeg decode frame unused %d bytes\n", buf_end - buf_ptr);

  1502. //    return buf_end - buf_ptr;

  1503.     return buf_ptr - buf;

  1504. }

  1505. 

  1506. static int mjpegb_decode_frame(AVCodecContext *avctx, 

  1507.                               void *data, int *data_size,

  1508.                               uint8_t *buf, int buf_size)

  1509. {

  1510.     MJpegDecodeContext *s = avctx->priv_data;

  1511.     uint8_t *buf_end, *buf_ptr;

  1512.     int i;

  1513.     AVPicture *picture = data;

  1514.     GetBitContext hgb; /* for the header */

  1515.     uint32_t dqt_offs, dht_offs, sof_offs, sos_offs, second_field_offs;

  1516.     uint32_t field_size;

  1517. 

  1518.     *data_size = 0;

  1519. 

  1520.     /* no supplementary picture */

  1521.     if (buf_size == 0)

  1522.         return 0;

  1523. 

  1524.     buf_ptr = buf;

  1525.     buf_end = buf + buf_size;

  1526.     

  1527. read_header:

  1528.     /* reset on every SOI */

  1529.     s->restart_interval = 0;

  1530. 

  1531.     init_get_bits(&hgb, buf_ptr, /*buf_size*/(buf_end - buf_ptr)*8);

  1532. 

  1533.     skip_bits(&hgb, 32); /* reserved zeros */

  1534.     

  1535.     if (get_bits(&hgb, 32) != be2me_32(ff_get_fourcc("mjpg")))

  1536.     {

  1537. 	dprintf("not mjpeg-b (bad fourcc)\n");

  1538. 	return 0;

  1539.     }

  1540. 

  1541.     field_size = get_bits(&hgb, 32); /* field size */

  1542.     dprintf("field size: 0x%x\n", field_size);

  1543.     skip_bits(&hgb, 32); /* padded field size */

  1544.     second_field_offs = get_bits(&hgb, 32);

  1545.     dprintf("second field offs: 0x%x\n", second_field_offs);

  1546.     if (second_field_offs)

  1547. 	s->interlaced = 1;

  1548. 

  1549.     dqt_offs = get_bits(&hgb, 32);

  1550.     dprintf("dqt offs: 0x%x\n", dqt_offs);

  1551.     if (dqt_offs)

  1552.     {

  1553. 	init_get_bits(&s->gb, buf+dqt_offs, (buf_end - (buf+dqt_offs))*8);

  1554. 	s->start_code = DQT;

  1555. 	mjpeg_decode_dqt(s);

  1556.     }

  1557.     

  1558.     dht_offs = get_bits(&hgb, 32);

  1559.     dprintf("dht offs: 0x%x\n", dht_offs);

  1560.     if (dht_offs)

  1561.     {

  1562. 	init_get_bits(&s->gb, buf+dht_offs, (buf_end - (buf+dht_offs))*8);

  1563. 	s->start_code = DHT;

  1564. 	mjpeg_decode_dht(s);

  1565.     }

  1566. 

  1567.     sof_offs = get_bits(&hgb, 32);

  1568.     dprintf("sof offs: 0x%x\n", sof_offs);

  1569.     if (sof_offs)

  1570.     {

  1571. 	init_get_bits(&s->gb, buf+sof_offs, (buf_end - (buf+sof_offs))*8);

  1572. 	s->start_code = SOF0;

  1573. 	if (mjpeg_decode_sof0(s) < 0)

  1574. 	    return -1;

  1575.     }

  1576. 

  1577.     sos_offs = get_bits(&hgb, 32);

  1578.     dprintf("sos offs: 0x%x\n", sos_offs);

  1579.     if (sos_offs)

  1580.     {

  1581. //	init_get_bits(&s->gb, buf+sos_offs, (buf_end - (buf+sos_offs))*8);

  1582. 	init_get_bits(&s->gb, buf+sos_offs, field_size*8);

  1583. 	s->start_code = SOS;

  1584. 	mjpeg_decode_sos(s);

  1585.     }

  1586. 

  1587.     skip_bits(&hgb, 32); /* start of data offset */

  1588. 

  1589.     if (s->interlaced) {

  1590.         s->bottom_field ^= 1;

  1591.         /* if not bottom field, do not output image yet */

  1592.         if (s->bottom_field && second_field_offs)

  1593. 	{

  1594. 	    buf_ptr = buf + second_field_offs;

  1595. 	    second_field_offs = 0;

  1596. 	    goto read_header;

  1597.     	}

  1598.     }

  1599. 

  1600.     for(i=0;i<3;i++) {

  1601.         picture->data[i] = s->current_picture[i];

  1602.         picture->linesize[i] = (s->interlaced) ?

  1603.     	    s->linesize[i] >> 1 : s->linesize[i];

  1604.     }

  1605.     *data_size = sizeof(AVPicture);

  1606.     avctx->height = s->height;

  1607.     if (s->interlaced)

  1608.         avctx->height *= 2;

  1609.     avctx->width = s->width;

  1610.     /* XXX: not complete test ! */

  1611.     switch((s->h_count[0] << 4) | s->v_count[0]) {

  1612.         case 0x11:

  1613.     	    avctx->pix_fmt = PIX_FMT_YUV444P;

  1614.             break;

  1615.         case 0x21:

  1616.             avctx->pix_fmt = PIX_FMT_YUV422P;

  1617.             break;

  1618.         default:

  1619. 	case 0x22:

  1620.             avctx->pix_fmt = PIX_FMT_YUV420P;

  1621.             break;

  1622.     }

  1623.     /* dummy quality */

  1624.     /* XXX: infer it with matrix */

  1625. //    avctx->quality = 3; 

  1626. 

  1627.     return buf_ptr - buf;

  1628. }

  1629. 

  1630. 

  1631. static int mjpeg_decode_end(AVCodecContext *avctx)

  1632. {

  1633.     MJpegDecodeContext *s = avctx->priv_data;

  1634.     int i, j;

  1635. 

  1636.     av_free(s->buffer);

  1637.     for(i=0;i<MAX_COMPONENTS;i++)

  1638.         av_free(s->current_picture[i]);

  1639.     for(i=0;i<2;i++) {

  1640.         for(j=0;j<4;j++)

  1641.             free_vlc(&s->vlcs[i][j]);

  1642.     }

  1643.     return 0;

  1644. }

  1645. 

  1646. AVCodec mjpeg_decoder = {

  1647.     "mjpeg",

  1648.     CODEC_TYPE_VIDEO,

  1649.     CODEC_ID_MJPEG,

  1650.     sizeof(MJpegDecodeContext),

  1651.     mjpeg_decode_init,

  1652.     NULL,

  1653.     mjpeg_decode_end,

  1654.     mjpeg_decode_frame,

  1655.     0,

  1656.     NULL

  1657. };

  1658. 

  1659. AVCodec mjpegb_decoder = {

  1660.     "mjpegb",

  1661.     CODEC_TYPE_VIDEO,

  1662.     CODEC_ID_MJPEGB,

  1663.     sizeof(MJpegDecodeContext),

  1664.     mjpeg_decode_init,

  1665.     NULL,

  1666.     mjpeg_decode_end,

  1667.     mjpegb_decode_frame,

  1668.     0,

  1669.     NULL

  1670. };