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FFmpeg/libavformat/avidec.c

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  1. /*

  2.  * AVI demuxer

  3.  * Copyright (c) 2001 Fabrice Bellard

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

  7.  * FFmpeg 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.  * FFmpeg 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 FFmpeg; if not, write to the Free Software

  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  20.  */

  21. 

  22. //#define DEBUG

  23. //#define DEBUG_SEEK

  24. 

  25. #include <strings.h>

  26. #include "libavutil/intreadwrite.h"

  27. #include "libavutil/bswap.h"

  28. #include "avformat.h"

  29. #include "avi.h"

  30. #include "dv.h"

  31. #include "riff.h"

  32. 

  33. #undef NDEBUG

  34. #include <assert.h>

  35. 

  36. typedef struct AVIStream {

  37.     int64_t frame_offset; /* current frame (video) or byte (audio) counter

  38.                          (used to compute the pts) */

  39.     int remaining;

  40.     int packet_size;

  41. 

  42.     int scale;

  43.     int rate;

  44.     int sample_size; /* size of one sample (or packet) (in the rate/scale sense) in bytes */

  45. 

  46.     int64_t cum_len; /* temporary storage (used during seek) */

  47. 

  48.     int prefix;                       ///< normally 'd'<<8 + 'c' or 'w'<<8 + 'b'

  49.     int prefix_count;

  50.     uint32_t pal[256];

  51.     int has_pal;

  52.     int dshow_block_align;            ///< block align variable used to emulate bugs in the MS dshow demuxer

  53. 

  54.     AVFormatContext *sub_ctx;

  55.     AVPacket sub_pkt;

  56.     uint8_t *sub_buffer;

  57. 

  58.     int64_t seek_pos;

  59. } AVIStream;

  60. 

  61. typedef struct {

  62.     int64_t  riff_end;

  63.     int64_t  movi_end;

  64.     int64_t  fsize;

  65.     int64_t movi_list;

  66.     int64_t last_pkt_pos;

  67.     int index_loaded;

  68.     int is_odml;

  69.     int non_interleaved;

  70.     int stream_index;

  71.     DVDemuxContext* dv_demux;

  72.     int odml_depth;

  73. #define MAX_ODML_DEPTH 1000

  74. } AVIContext;

  75. 

  76. static const char avi_headers[][8] = {

  77.     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', ' ' },

  78.     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 'X' },

  79.     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 0x19},

  80.     { 'O', 'N', '2', ' ',    'O', 'N', '2', 'f' },

  81.     { 'R', 'I', 'F', 'F',    'A', 'M', 'V', ' ' },

  82.     { 0 }

  83. };

  84. 

  85. static int avi_load_index(AVFormatContext *s);

  86. static int guess_ni_flag(AVFormatContext *s);

  87. 

  88. #define print_tag(str, tag, size)                       \

  89.     av_dlog(NULL, "%s: tag=%c%c%c%c size=0x%x\n",       \

  90.            str, tag & 0xff,                             \

  91.            (tag >> 8) & 0xff,                           \

  92.            (tag >> 16) & 0xff,                          \

  93.            (tag >> 24) & 0xff,                          \

  94.            size)

  95. 

  96. static inline int get_duration(AVIStream *ast, int len){

  97.     if(ast->sample_size){

  98.         return len;

  99.     }else if (ast->dshow_block_align){

  100.         return (len + ast->dshow_block_align - 1)/ast->dshow_block_align;

  101.     }else

  102.         return 1;

  103. }

  104. 

  105. static int get_riff(AVFormatContext *s, AVIOContext *pb)

  106. {

  107.     AVIContext *avi = s->priv_data;

  108.     char header[8];

  109.     int i;

  110. 

  111.     /* check RIFF header */

  112.     avio_read(pb, header, 4);

  113.     avi->riff_end = avio_rl32(pb);  /* RIFF chunk size */

  114.     avi->riff_end += avio_tell(pb); /* RIFF chunk end */

  115.     avio_read(pb, header+4, 4);

  116. 

  117.     for(i=0; avi_headers[i][0]; i++)

  118.         if(!memcmp(header, avi_headers[i], 8))

  119.             break;

  120.     if(!avi_headers[i][0])

  121.         return -1;

  122. 

  123.     if(header[7] == 0x19)

  124.         av_log(s, AV_LOG_INFO, "This file has been generated by a totally broken muxer.\n");

  125. 

  126.     return 0;

  127. }

  128. 

  129. static int read_braindead_odml_indx(AVFormatContext *s, int frame_num){

  130.     AVIContext *avi = s->priv_data;

  131.     AVIOContext *pb = s->pb;

  132.     int longs_pre_entry= avio_rl16(pb);

  133.     int index_sub_type = avio_r8(pb);

  134.     int index_type     = avio_r8(pb);

  135.     int entries_in_use = avio_rl32(pb);

  136.     int chunk_id       = avio_rl32(pb);

  137.     int64_t base       = avio_rl64(pb);

  138.     int stream_id= 10*((chunk_id&0xFF) - '0') + (((chunk_id>>8)&0xFF) - '0');

  139.     AVStream *st;

  140.     AVIStream *ast;

  141.     int i;

  142.     int64_t last_pos= -1;

  143.     int64_t filesize= avio_size(s->pb);

  144. 

  145. #ifdef DEBUG_SEEK

  146.     av_log(s, AV_LOG_ERROR, "longs_pre_entry:%d index_type:%d entries_in_use:%d chunk_id:%X base:%16"PRIX64"\n",

  147.         longs_pre_entry,index_type, entries_in_use, chunk_id, base);

  148. #endif

  149. 

  150.     if(stream_id >= s->nb_streams || stream_id < 0)

  151.         return -1;

  152.     st= s->streams[stream_id];

  153.     ast = st->priv_data;

  154. 

  155.     if(index_sub_type)

  156.         return -1;

  157. 

  158.     avio_rl32(pb);

  159. 

  160.     if(index_type && longs_pre_entry != 2)

  161.         return -1;

  162.     if(index_type>1)

  163.         return -1;

  164. 

  165.     if(filesize > 0 && base >= filesize){

  166.         av_log(s, AV_LOG_ERROR, "ODML index invalid\n");

  167.         if(base>>32 == (base & 0xFFFFFFFF) && (base & 0xFFFFFFFF) < filesize && filesize <= 0xFFFFFFFF)

  168.             base &= 0xFFFFFFFF;

  169.         else

  170.             return -1;

  171.     }

  172. 

  173.     for(i=0; i<entries_in_use; i++){

  174.         if(index_type){

  175.             int64_t pos= avio_rl32(pb) + base - 8;

  176.             int len    = avio_rl32(pb);

  177.             int key= len >= 0;

  178.             len &= 0x7FFFFFFF;

  179. 

  180. #ifdef DEBUG_SEEK

  181.             av_log(s, AV_LOG_ERROR, "pos:%"PRId64", len:%X\n", pos, len);

  182. #endif

  183.             if(url_feof(pb))

  184.                 return -1;

  185. 

  186.             if(last_pos == pos || pos == base - 8)

  187.                 avi->non_interleaved= 1;

  188.             if(last_pos != pos && (len || !ast->sample_size))

  189.                 av_add_index_entry(st, pos, ast->cum_len, len, 0, key ? AVINDEX_KEYFRAME : 0);

  190. 

  191.             ast->cum_len += get_duration(ast, len);

  192.             last_pos= pos;

  193.         }else{

  194.             int64_t offset, pos;

  195.             int duration;

  196.             offset = avio_rl64(pb);

  197.             avio_rl32(pb);       /* size */

  198.             duration = avio_rl32(pb);

  199. 

  200.             if(url_feof(pb))

  201.                 return -1;

  202. 

  203.             pos = avio_tell(pb);

  204. 

  205.             if(avi->odml_depth > MAX_ODML_DEPTH){

  206.                 av_log(s, AV_LOG_ERROR, "Too deeply nested ODML indexes\n");

  207.                 return -1;

  208.             }

  209. 

  210.             avio_seek(pb, offset+8, SEEK_SET);

  211.             avi->odml_depth++;

  212.             read_braindead_odml_indx(s, frame_num);

  213.             avi->odml_depth--;

  214.             frame_num += duration;

  215. 

  216.             avio_seek(pb, pos, SEEK_SET);

  217.         }

  218.     }

  219.     avi->index_loaded=1;

  220.     return 0;

  221. }

  222. 

  223. static void clean_index(AVFormatContext *s){

  224.     int i;

  225.     int64_t j;

  226. 

  227.     for(i=0; i<s->nb_streams; i++){

  228.         AVStream *st = s->streams[i];

  229.         AVIStream *ast = st->priv_data;

  230.         int n= st->nb_index_entries;

  231.         int max= ast->sample_size;

  232.         int64_t pos, size, ts;

  233. 

  234.         if(n != 1 || ast->sample_size==0)

  235.             continue;

  236. 

  237.         while(max < 1024) max+=max;

  238. 

  239.         pos= st->index_entries[0].pos;

  240.         size= st->index_entries[0].size;

  241.         ts= st->index_entries[0].timestamp;

  242. 

  243.         for(j=0; j<size; j+=max){

  244.             av_add_index_entry(st, pos+j, ts+j, FFMIN(max, size-j), 0, AVINDEX_KEYFRAME);

  245.         }

  246.     }

  247. }

  248. 

  249. static int avi_read_tag(AVFormatContext *s, AVStream *st, uint32_t tag, uint32_t size)

  250. {

  251.     AVIOContext *pb = s->pb;

  252.     char key[5] = {0}, *value;

  253. 

  254.     size += (size & 1);

  255. 

  256.     if (size == UINT_MAX)

  257.         return -1;

  258.     value = av_malloc(size+1);

  259.     if (!value)

  260.         return -1;

  261.     avio_read(pb, value, size);

  262.     value[size]=0;

  263. 

  264.     AV_WL32(key, tag);

  265. 

  266.     return av_metadata_set2(st ? &st->metadata : &s->metadata, key, value,

  267.                             AV_METADATA_DONT_STRDUP_VAL);

  268. }

  269. 

  270. static void avi_read_info(AVFormatContext *s, uint64_t end)

  271. {

  272.     while (avio_tell(s->pb) < end) {

  273.         uint32_t tag  = avio_rl32(s->pb);

  274.         uint32_t size = avio_rl32(s->pb);

  275.         avi_read_tag(s, NULL, tag, size);

  276.     }

  277. }

  278. 

  279. static const char months[12][4] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",

  280.                                     "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };

  281. 

  282. static void avi_metadata_creation_time(AVMetadata **metadata, char *date)

  283. {

  284.     char month[4], time[9], buffer[64];

  285.     int i, day, year;

  286.     /* parse standard AVI date format (ie. "Mon Mar 10 15:04:43 2003") */

  287.     if (sscanf(date, "%*3s%*[ ]%3s%*[ ]%2d%*[ ]%8s%*[ ]%4d",

  288.                month, &day, time, &year) == 4) {

  289.         for (i=0; i<12; i++)

  290.             if (!strcasecmp(month, months[i])) {

  291.                 snprintf(buffer, sizeof(buffer), "%.4d-%.2d-%.2d %s",

  292.                          year, i+1, day, time);

  293.                 av_metadata_set2(metadata, "creation_time", buffer, 0);

  294.             }

  295.     } else if (date[4] == '/' && date[7] == '/') {

  296.         date[4] = date[7] = '-';

  297.         av_metadata_set2(metadata, "creation_time", date, 0);

  298.     }

  299. }

  300. 

  301. static void avi_read_nikon(AVFormatContext *s, uint64_t end)

  302. {

  303.     while (avio_tell(s->pb) < end) {

  304.         uint32_t tag  = avio_rl32(s->pb);

  305.         uint32_t size = avio_rl32(s->pb);

  306.         switch (tag) {

  307.         case MKTAG('n', 'c', 't', 'g'): {  /* Nikon Tags */

  308.             uint64_t tag_end = avio_tell(s->pb) + size;

  309.             while (avio_tell(s->pb) < tag_end) {

  310.                 uint16_t tag  = avio_rl16(s->pb);

  311.                 uint16_t size = avio_rl16(s->pb);

  312.                 const char *name = NULL;

  313.                 char buffer[64] = {0};

  314.                 size -= avio_read(s->pb, buffer,

  315.                                    FFMIN(size, sizeof(buffer)-1));

  316.                 switch (tag) {

  317.                 case 0x03:  name = "maker";  break;

  318.                 case 0x04:  name = "model";  break;

  319.                 case 0x13:  name = "creation_time";

  320.                     if (buffer[4] == ':' && buffer[7] == ':')

  321.                         buffer[4] = buffer[7] = '-';

  322.                     break;

  323.                 }

  324.                 if (name)

  325.                     av_metadata_set2(&s->metadata, name, buffer, 0);

  326.                 avio_skip(s->pb, size);

  327.             }

  328.             break;

  329.         }

  330.         default:

  331.             avio_skip(s->pb, size);

  332.             break;

  333.         }

  334.     }

  335. }

  336. 

  337. static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)

  338. {

  339.     AVIContext *avi = s->priv_data;

  340.     AVIOContext *pb = s->pb;

  341.     unsigned int tag, tag1, handler;

  342.     int codec_type, stream_index, frame_period, bit_rate;

  343.     unsigned int size;

  344.     int i;

  345.     AVStream *st;

  346.     AVIStream *ast = NULL;

  347.     int avih_width=0, avih_height=0;

  348.     int amv_file_format=0;

  349.     uint64_t list_end = 0;

  350.     int ret;

  351. 

  352.     avi->stream_index= -1;

  353. 

  354.     if (get_riff(s, pb) < 0)

  355.         return -1;

  356. 

  357.     avi->fsize = avio_size(pb);

  358.     if(avi->fsize<=0)

  359.         avi->fsize= avi->riff_end == 8 ? INT64_MAX : avi->riff_end;

  360. 

  361.     /* first list tag */

  362.     stream_index = -1;

  363.     codec_type = -1;

  364.     frame_period = 0;

  365.     for(;;) {

  366.         if (url_feof(pb))

  367.             goto fail;

  368.         tag = avio_rl32(pb);

  369.         size = avio_rl32(pb);

  370. 

  371.         print_tag("tag", tag, size);

  372. 

  373.         switch(tag) {

  374.         case MKTAG('L', 'I', 'S', 'T'):

  375.             list_end = avio_tell(pb) + size;

  376.             /* Ignored, except at start of video packets. */

  377.             tag1 = avio_rl32(pb);

  378. 

  379.             print_tag("list", tag1, 0);

  380. 

  381.             if (tag1 == MKTAG('m', 'o', 'v', 'i')) {

  382.                 avi->movi_list = avio_tell(pb) - 4;

  383.                 if(size) avi->movi_end = avi->movi_list + size + (size & 1);

  384.                 else     avi->movi_end = avio_size(pb);

  385.                 av_dlog(NULL, "movi end=%"PRIx64"\n", avi->movi_end);

  386.                 goto end_of_header;

  387.             }

  388.             else if (tag1 == MKTAG('I', 'N', 'F', 'O'))

  389.                 avi_read_info(s, list_end);

  390.             else if (tag1 == MKTAG('n', 'c', 'd', 't'))

  391.                 avi_read_nikon(s, list_end);

  392. 

  393.             break;

  394.         case MKTAG('I', 'D', 'I', 'T'): {

  395.             unsigned char date[64] = {0};

  396.             size += (size & 1);

  397.             size -= avio_read(pb, date, FFMIN(size, sizeof(date)-1));

  398.             avio_skip(pb, size);

  399.             avi_metadata_creation_time(&s->metadata, date);

  400.             break;

  401.         }

  402.         case MKTAG('d', 'm', 'l', 'h'):

  403.             avi->is_odml = 1;

  404.             avio_skip(pb, size + (size & 1));

  405.             break;

  406.         case MKTAG('a', 'm', 'v', 'h'):

  407.             amv_file_format=1;

  408.         case MKTAG('a', 'v', 'i', 'h'):

  409.             /* AVI header */

  410.             /* using frame_period is bad idea */

  411.             frame_period = avio_rl32(pb);

  412.             bit_rate = avio_rl32(pb) * 8;

  413.             avio_rl32(pb);

  414.             avi->non_interleaved |= avio_rl32(pb) & AVIF_MUSTUSEINDEX;

  415. 

  416.             avio_skip(pb, 2 * 4);

  417.             avio_rl32(pb);

  418.             avio_rl32(pb);

  419.             avih_width=avio_rl32(pb);

  420.             avih_height=avio_rl32(pb);

  421. 

  422.             avio_skip(pb, size - 10 * 4);

  423.             break;

  424.         case MKTAG('s', 't', 'r', 'h'):

  425.             /* stream header */

  426. 

  427.             tag1 = avio_rl32(pb);

  428.             handler = avio_rl32(pb); /* codec tag */

  429. 

  430.             if(tag1 == MKTAG('p', 'a', 'd', 's')){

  431.                 avio_skip(pb, size - 8);

  432.                 break;

  433.             }else{

  434.                 stream_index++;

  435.                 st = av_new_stream(s, stream_index);

  436.                 if (!st)

  437.                     goto fail;

  438. 

  439.                 ast = av_mallocz(sizeof(AVIStream));

  440.                 if (!ast)

  441.                     goto fail;

  442.                 st->priv_data = ast;

  443.             }

  444.             if(amv_file_format)

  445.                 tag1 = stream_index ? MKTAG('a','u','d','s') : MKTAG('v','i','d','s');

  446. 

  447.             print_tag("strh", tag1, -1);

  448. 

  449.             if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){

  450.                 int64_t dv_dur;

  451. 

  452.                 /*

  453.                  * After some consideration -- I don't think we

  454.                  * have to support anything but DV in type1 AVIs.

  455.                  */

  456.                 if (s->nb_streams != 1)

  457.                     goto fail;

  458. 

  459.                 if (handler != MKTAG('d', 'v', 's', 'd') &&

  460.                     handler != MKTAG('d', 'v', 'h', 'd') &&

  461.                     handler != MKTAG('d', 'v', 's', 'l'))

  462.                    goto fail;

  463. 

  464.                 ast = s->streams[0]->priv_data;

  465.                 av_freep(&s->streams[0]->codec->extradata);

  466.                 av_freep(&s->streams[0]->codec);

  467.                 av_freep(&s->streams[0]);

  468.                 s->nb_streams = 0;

  469.                 if (CONFIG_DV_DEMUXER) {

  470.                     avi->dv_demux = dv_init_demux(s);

  471.                     if (!avi->dv_demux)

  472.                         goto fail;

  473.                 }

  474.                 s->streams[0]->priv_data = ast;

  475.                 avio_skip(pb, 3 * 4);

  476.                 ast->scale = avio_rl32(pb);

  477.                 ast->rate = avio_rl32(pb);

  478.                 avio_skip(pb, 4);  /* start time */

  479. 

  480.                 dv_dur = avio_rl32(pb);

  481.                 if (ast->scale > 0 && ast->rate > 0 && dv_dur > 0) {

  482.                     dv_dur *= AV_TIME_BASE;

  483.                     s->duration = av_rescale(dv_dur, ast->scale, ast->rate);

  484.                 }

  485.                 /*

  486.                  * else, leave duration alone; timing estimation in utils.c

  487.                  *      will make a guess based on bitrate.

  488.                  */

  489. 

  490.                 stream_index = s->nb_streams - 1;

  491.                 avio_skip(pb, size - 9*4);

  492.                 break;

  493.             }

  494. 

  495.             assert(stream_index < s->nb_streams);

  496.             st->codec->stream_codec_tag= handler;

  497. 

  498.             avio_rl32(pb); /* flags */

  499.             avio_rl16(pb); /* priority */

  500.             avio_rl16(pb); /* language */

  501.             avio_rl32(pb); /* initial frame */

  502.             ast->scale = avio_rl32(pb);

  503.             ast->rate = avio_rl32(pb);

  504.             if(!(ast->scale && ast->rate)){

  505.                 av_log(s, AV_LOG_WARNING, "scale/rate is %u/%u which is invalid. (This file has been generated by broken software.)\n", ast->scale, ast->rate);

  506.                 if(frame_period){

  507.                     ast->rate = 1000000;

  508.                     ast->scale = frame_period;

  509.                 }else{

  510.                     ast->rate = 25;

  511.                     ast->scale = 1;

  512.                 }

  513.             }

  514.             av_set_pts_info(st, 64, ast->scale, ast->rate);

  515. 

  516.             ast->cum_len=avio_rl32(pb); /* start */

  517.             st->nb_frames = avio_rl32(pb);

  518. 

  519.             st->start_time = 0;

  520.             avio_rl32(pb); /* buffer size */

  521.             avio_rl32(pb); /* quality */

  522.             ast->sample_size = avio_rl32(pb); /* sample ssize */

  523.             ast->cum_len *= FFMAX(1, ast->sample_size);

  524. //            av_log(s, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);

  525. 

  526.             switch(tag1) {

  527.             case MKTAG('v', 'i', 'd', 's'):

  528.                 codec_type = AVMEDIA_TYPE_VIDEO;

  529. 

  530.                 ast->sample_size = 0;

  531.                 break;

  532.             case MKTAG('a', 'u', 'd', 's'):

  533.                 codec_type = AVMEDIA_TYPE_AUDIO;

  534.                 break;

  535.             case MKTAG('t', 'x', 't', 's'):

  536.                 codec_type = AVMEDIA_TYPE_SUBTITLE;

  537.                 break;

  538.             case MKTAG('d', 'a', 't', 's'):

  539.                 codec_type = AVMEDIA_TYPE_DATA;

  540.                 break;

  541.             default:

  542.                 av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);

  543.                 goto fail;

  544.             }

  545.             if(ast->sample_size == 0)

  546.                 st->duration = st->nb_frames;

  547.             ast->frame_offset= ast->cum_len;

  548.             avio_skip(pb, size - 12 * 4);

  549.             break;

  550.         case MKTAG('s', 't', 'r', 'f'):

  551.             /* stream header */

  552.             if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {

  553.                 avio_skip(pb, size);

  554.             } else {

  555.                 uint64_t cur_pos = avio_tell(pb);

  556.                 if (cur_pos < list_end)

  557.                     size = FFMIN(size, list_end - cur_pos);

  558.                 st = s->streams[stream_index];

  559.                 switch(codec_type) {

  560.                 case AVMEDIA_TYPE_VIDEO:

  561.                     if(amv_file_format){

  562.                         st->codec->width=avih_width;

  563.                         st->codec->height=avih_height;

  564.                         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

  565.                         st->codec->codec_id = CODEC_ID_AMV;

  566.                         avio_skip(pb, size);

  567.                         break;

  568.                     }

  569.                     tag1 = ff_get_bmp_header(pb, st);

  570. 

  571.                     if (tag1 == MKTAG('D', 'X', 'S', 'B') || tag1 == MKTAG('D','X','S','A')) {

  572.                         st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;

  573.                         st->codec->codec_tag = tag1;

  574.                         st->codec->codec_id = CODEC_ID_XSUB;

  575.                         break;

  576.                     }

  577. 

  578.                     if(size > 10*4 && size<(1<<30)){

  579.                         st->codec->extradata_size= size - 10*4;

  580.                         st->codec->extradata= av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);

  581.                         if (!st->codec->extradata) {

  582.                             st->codec->extradata_size= 0;

  583.                             return AVERROR(ENOMEM);

  584.                         }

  585.                         avio_read(pb, st->codec->extradata, st->codec->extradata_size);

  586.                     }

  587. 

  588.                     if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly

  589.                         avio_r8(pb);

  590. 

  591.                     /* Extract palette from extradata if bpp <= 8. */

  592.                     /* This code assumes that extradata contains only palette. */

  593.                     /* This is true for all paletted codecs implemented in FFmpeg. */

  594.                     if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {

  595.                         int pal_size = (1 << st->codec->bits_per_coded_sample) << 2;

  596.                         const uint8_t *pal_src;

  597. 

  598.                         pal_size = FFMIN(pal_size, st->codec->extradata_size);

  599.                         pal_src = st->codec->extradata + st->codec->extradata_size - pal_size;

  600. #if HAVE_BIGENDIAN

  601.                         for (i = 0; i < pal_size/4; i++)

  602.                             ast->pal[i] = AV_RL32(pal_src+4*i);

  603. #else

  604.                         memcpy(ast->pal, pal_src, pal_size);

  605. #endif

  606.                         ast->has_pal = 1;

  607.                     }

  608. 

  609.                     print_tag("video", tag1, 0);

  610. 

  611.                     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

  612.                     st->codec->codec_tag = tag1;

  613.                     st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, tag1);

  614.                     st->need_parsing = AVSTREAM_PARSE_HEADERS; // This is needed to get the pict type which is necessary for generating correct pts.

  615.                     // Support "Resolution 1:1" for Avid AVI Codec

  616.                     if(tag1 == MKTAG('A', 'V', 'R', 'n') &&

  617.                        st->codec->extradata_size >= 31 &&

  618.                        !memcmp(&st->codec->extradata[28], "1:1", 3))

  619.                         st->codec->codec_id = CODEC_ID_RAWVIDEO;

  620. 

  621.                     if(st->codec->codec_tag==0 && st->codec->height > 0 && st->codec->extradata_size < 1U<<30){

  622.                         st->codec->extradata_size+= 9;

  623.                         st->codec->extradata= av_realloc(st->codec->extradata, st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);

  624.                         if(st->codec->extradata)

  625.                             memcpy(st->codec->extradata + st->codec->extradata_size - 9, "BottomUp", 9);

  626.                     }

  627.                     st->codec->height= FFABS(st->codec->height);

  628. 

  629. //                    avio_skip(pb, size - 5 * 4);

  630.                     break;

  631.                 case AVMEDIA_TYPE_AUDIO:

  632.                     ret = ff_get_wav_header(pb, st->codec, size);

  633.                     if (ret < 0)

  634.                         return ret;

  635.                     ast->dshow_block_align= st->codec->block_align;

  636.                     if(ast->sample_size && st->codec->block_align && ast->sample_size != st->codec->block_align){

  637.                         av_log(s, AV_LOG_WARNING, "sample size (%d) != block align (%d)\n", ast->sample_size, st->codec->block_align);

  638.                         ast->sample_size= st->codec->block_align;

  639.                     }

  640.                     if (size&1) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */

  641.                         avio_skip(pb, 1);

  642.                     /* Force parsing as several audio frames can be in

  643.                      * one packet and timestamps refer to packet start. */

  644.                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;

  645.                     /* ADTS header is in extradata, AAC without header must be

  646.                      * stored as exact frames. Parser not needed and it will

  647.                      * fail. */

  648.                     if (st->codec->codec_id == CODEC_ID_AAC && st->codec->extradata_size)

  649.                         st->need_parsing = AVSTREAM_PARSE_NONE;

  650.                     /* AVI files with Xan DPCM audio (wrongly) declare PCM

  651.                      * audio in the header but have Axan as stream_code_tag. */

  652.                     if (st->codec->stream_codec_tag == AV_RL32("Axan")){

  653.                         st->codec->codec_id  = CODEC_ID_XAN_DPCM;

  654.                         st->codec->codec_tag = 0;

  655.                     }

  656.                     if (amv_file_format){

  657.                         st->codec->codec_id  = CODEC_ID_ADPCM_IMA_AMV;

  658.                         ast->dshow_block_align = 0;

  659.                     }

  660.                     break;

  661.                 case AVMEDIA_TYPE_SUBTITLE:

  662.                     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;

  663.                     st->request_probe= 1;

  664.                     break;

  665.                 default:

  666.                     st->codec->codec_type = AVMEDIA_TYPE_DATA;

  667.                     st->codec->codec_id= CODEC_ID_NONE;

  668.                     st->codec->codec_tag= 0;

  669.                     avio_skip(pb, size);

  670.                     break;

  671.                 }

  672.             }

  673.             break;

  674.         case MKTAG('i', 'n', 'd', 'x'):

  675.             i= avio_tell(pb);

  676.             if(pb->seekable && !(s->flags & AVFMT_FLAG_IGNIDX)){

  677.                 read_braindead_odml_indx(s, 0);

  678.             }

  679.             avio_seek(pb, i+size, SEEK_SET);

  680.             break;

  681.         case MKTAG('v', 'p', 'r', 'p'):

  682.             if(stream_index < (unsigned)s->nb_streams && size > 9*4){

  683.                 AVRational active, active_aspect;

  684. 

  685.                 st = s->streams[stream_index];

  686.                 avio_rl32(pb);

  687.                 avio_rl32(pb);

  688.                 avio_rl32(pb);

  689.                 avio_rl32(pb);

  690.                 avio_rl32(pb);

  691. 

  692.                 active_aspect.den= avio_rl16(pb);

  693.                 active_aspect.num= avio_rl16(pb);

  694.                 active.num       = avio_rl32(pb);

  695.                 active.den       = avio_rl32(pb);

  696.                 avio_rl32(pb); //nbFieldsPerFrame

  697. 

  698.                 if(active_aspect.num && active_aspect.den && active.num && active.den){

  699.                     st->sample_aspect_ratio= av_div_q(active_aspect, active);

  700. //av_log(s, AV_LOG_ERROR, "vprp %d/%d %d/%d\n", active_aspect.num, active_aspect.den, active.num, active.den);

  701.                 }

  702.                 size -= 9*4;

  703.             }

  704.             avio_skip(pb, size);

  705.             break;

  706.         case MKTAG('s', 't', 'r', 'n'):

  707.             if(s->nb_streams){

  708.                 avi_read_tag(s, s->streams[s->nb_streams-1], tag, size);

  709.                 break;

  710.             }

  711.         default:

  712.             if(size > 1000000){

  713.                 av_log(s, AV_LOG_ERROR, "Something went wrong during header parsing, "

  714.                                         "I will ignore it and try to continue anyway.\n");

  715.                 avi->movi_list = avio_tell(pb) - 4;

  716.                 avi->movi_end  = avio_size(pb);

  717.                 goto end_of_header;

  718.             }

  719.             /* skip tag */

  720.             size += (size & 1);

  721.             avio_skip(pb, size);

  722.             break;

  723.         }

  724.     }

  725.  end_of_header:

  726.     /* check stream number */

  727.     if (stream_index != s->nb_streams - 1) {

  728.     fail:

  729.         return -1;

  730.     }

  731. 

  732.     if(!avi->index_loaded && pb->seekable)

  733.         avi_load_index(s);

  734.     avi->index_loaded = 1;

  735.     avi->non_interleaved |= guess_ni_flag(s) | (s->flags & AVFMT_FLAG_SORT_DTS);

  736.     for(i=0; i<s->nb_streams; i++){

  737.         AVStream *st = s->streams[i];

  738.         if(st->nb_index_entries)

  739.             break;

  740.     }

  741.     // DV-in-AVI cannot be non-interleaved, if set this must be

  742.     // a mis-detection.

  743.     if(avi->dv_demux)

  744.         avi->non_interleaved=0;

  745.     if(i==s->nb_streams && avi->non_interleaved) {

  746.         av_log(s, AV_LOG_WARNING, "non-interleaved AVI without index, switching to interleaved\n");

  747.         avi->non_interleaved=0;

  748.     }

  749. 

  750.     if(avi->non_interleaved) {

  751.         av_log(s, AV_LOG_INFO, "non-interleaved AVI\n");

  752.         clean_index(s);

  753.     }

  754. 

  755.     ff_metadata_conv_ctx(s, NULL, ff_avi_metadata_conv);

  756. 

  757.     return 0;

  758. }

  759. 

  760. static int read_gab2_sub(AVStream *st, AVPacket *pkt) {

  761.     if (!strcmp(pkt->data, "GAB2") && AV_RL16(pkt->data+5) == 2) {

  762.         uint8_t desc[256];

  763.         int score = AVPROBE_SCORE_MAX / 2, ret;

  764.         AVIStream *ast = st->priv_data;

  765.         AVInputFormat *sub_demuxer;

  766.         AVRational time_base;

  767.         AVIOContext *pb = avio_alloc_context( pkt->data + 7,

  768.                                               pkt->size - 7,

  769.                                               0, NULL, NULL, NULL, NULL);

  770.         AVProbeData pd;

  771.         unsigned int desc_len = avio_rl32(pb);

  772. 

  773.         if (desc_len > pb->buf_end - pb->buf_ptr)

  774.             goto error;

  775. 

  776.         ret = avio_get_str16le(pb, desc_len, desc, sizeof(desc));

  777.         avio_skip(pb, desc_len - ret);

  778.         if (*desc)

  779.             av_metadata_set2(&st->metadata, "title", desc, 0);

  780. 

  781.         avio_rl16(pb);   /* flags? */

  782.         avio_rl32(pb);   /* data size */

  783. 

  784.         pd = (AVProbeData) { .buf = pb->buf_ptr, .buf_size = pb->buf_end - pb->buf_ptr };

  785.         if (!(sub_demuxer = av_probe_input_format2(&pd, 1, &score)))

  786.             goto error;

  787. 

  788.         if (!av_open_input_stream(&ast->sub_ctx, pb, "", sub_demuxer, NULL)) {

  789.             av_read_packet(ast->sub_ctx, &ast->sub_pkt);

  790.             *st->codec = *ast->sub_ctx->streams[0]->codec;

  791.             ast->sub_ctx->streams[0]->codec->extradata = NULL;

  792.             time_base = ast->sub_ctx->streams[0]->time_base;

  793.             av_set_pts_info(st, 64, time_base.num, time_base.den);

  794.         }

  795.         ast->sub_buffer = pkt->data;

  796.         memset(pkt, 0, sizeof(*pkt));

  797.         return 1;

  798. error:

  799.         av_freep(&pb);

  800.     }

  801.     return 0;

  802. }

  803. 

  804. static AVStream *get_subtitle_pkt(AVFormatContext *s, AVStream *next_st,

  805.                                   AVPacket *pkt)

  806. {

  807.     AVIStream *ast, *next_ast = next_st->priv_data;

  808.     int64_t ts, next_ts, ts_min = INT64_MAX;

  809.     AVStream *st, *sub_st = NULL;

  810.     int i;

  811. 

  812.     next_ts = av_rescale_q(next_ast->frame_offset, next_st->time_base,

  813.                            AV_TIME_BASE_Q);

  814. 

  815.     for (i=0; i<s->nb_streams; i++) {

  816.         st  = s->streams[i];

  817.         ast = st->priv_data;

  818.         if (st->discard < AVDISCARD_ALL && ast && ast->sub_pkt.data) {

  819.             ts = av_rescale_q(ast->sub_pkt.dts, st->time_base, AV_TIME_BASE_Q);

  820.             if (ts <= next_ts && ts < ts_min) {

  821.                 ts_min = ts;

  822.                 sub_st = st;

  823.             }

  824.         }

  825.     }

  826. 

  827.     if (sub_st) {

  828.         ast = sub_st->priv_data;

  829.         *pkt = ast->sub_pkt;

  830.         pkt->stream_index = sub_st->index;

  831.         if (av_read_packet(ast->sub_ctx, &ast->sub_pkt) < 0)

  832.             ast->sub_pkt.data = NULL;

  833.     }

  834.     return sub_st;

  835. }

  836. 

  837. static int get_stream_idx(int *d){

  838.     if(    d[0] >= '0' && d[0] <= '9'

  839.         && d[1] >= '0' && d[1] <= '9'){

  840.         return (d[0] - '0') * 10 + (d[1] - '0');

  841.     }else{

  842.         return 100; //invalid stream ID

  843.     }

  844. }

  845. 

  846. static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)

  847. {

  848.     AVIContext *avi = s->priv_data;

  849.     AVIOContext *pb = s->pb;

  850.     int n, d[8];

  851.     unsigned int size;

  852.     int64_t i, sync;

  853.     void* dstr;

  854. 

  855.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  856.         int size = dv_get_packet(avi->dv_demux, pkt);

  857.         if (size >= 0)

  858.             return size;

  859.     }

  860. 

  861.     if(avi->non_interleaved){

  862.         int best_stream_index = 0;

  863.         AVStream *best_st= NULL;

  864.         AVIStream *best_ast;

  865.         int64_t best_ts= INT64_MAX;

  866.         int i;

  867. 

  868.         for(i=0; i<s->nb_streams; i++){

  869.             AVStream *st = s->streams[i];

  870.             AVIStream *ast = st->priv_data;

  871.             int64_t ts= ast->frame_offset;

  872.             int64_t last_ts;

  873. 

  874.             if(!st->nb_index_entries)

  875.                 continue;

  876. 

  877.             last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;

  878.             if(!ast->remaining && ts > last_ts)

  879.                 continue;

  880. 

  881.             ts = av_rescale_q(ts, st->time_base, (AVRational){FFMAX(1, ast->sample_size), AV_TIME_BASE});

  882. 

  883. //            av_log(s, AV_LOG_DEBUG, "%"PRId64" %d/%d %"PRId64"\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);

  884.             if(ts < best_ts){

  885.                 best_ts= ts;

  886.                 best_st= st;

  887.                 best_stream_index= i;

  888.             }

  889.         }

  890.         if(!best_st)

  891.             return -1;

  892. 

  893.         best_ast = best_st->priv_data;

  894.         best_ts = av_rescale_q(best_ts, (AVRational){FFMAX(1, best_ast->sample_size), AV_TIME_BASE}, best_st->time_base);

  895.         if(best_ast->remaining)

  896.             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);

  897.         else{

  898.             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);

  899.             if(i>=0)

  900.                 best_ast->frame_offset= best_st->index_entries[i].timestamp;

  901.         }

  902. 

  903. //        av_log(s, AV_LOG_DEBUG, "%d\n", i);

  904.         if(i>=0){

  905.             int64_t pos= best_st->index_entries[i].pos;

  906.             pos += best_ast->packet_size - best_ast->remaining;

  907.             avio_seek(s->pb, pos + 8, SEEK_SET);

  908. //        av_log(s, AV_LOG_DEBUG, "pos=%"PRId64"\n", pos);

  909. 

  910.             assert(best_ast->remaining <= best_ast->packet_size);

  911. 

  912.             avi->stream_index= best_stream_index;

  913.             if(!best_ast->remaining)

  914.                 best_ast->packet_size=

  915.                 best_ast->remaining= best_st->index_entries[i].size;

  916.         }

  917.     }

  918. 

  919. resync:

  920.     if(avi->stream_index >= 0){

  921.         AVStream *st= s->streams[ avi->stream_index ];

  922.         AVIStream *ast= st->priv_data;

  923.         int size, err;

  924. 

  925.         if(get_subtitle_pkt(s, st, pkt))

  926.             return 0;

  927. 

  928.         if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM

  929.             size= INT_MAX;

  930.         else if(ast->sample_size < 32)

  931.             // arbitrary multiplier to avoid tiny packets for raw PCM data

  932.             size= 1024*ast->sample_size;

  933.         else

  934.             size= ast->sample_size;

  935. 

  936.         if(size > ast->remaining)

  937.             size= ast->remaining;

  938.         avi->last_pkt_pos= avio_tell(pb);

  939.         err= av_get_packet(pb, pkt, size);

  940.         if(err<0)

  941.             return err;

  942. 

  943.         if(ast->has_pal && pkt->data && pkt->size<(unsigned)INT_MAX/2){

  944.             uint8_t *pal;

  945.             pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE);

  946.             if(!pal){

  947.                 av_log(s, AV_LOG_ERROR, "Failed to allocate data for palette\n");

  948.             }else{

  949.                 memcpy(pal, ast->pal, AVPALETTE_SIZE);

  950.                 ast->has_pal = 0;

  951.             }

  952.         }

  953. 

  954.         if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  955.             dstr = pkt->destruct;

  956.             size = dv_produce_packet(avi->dv_demux, pkt,

  957.                                     pkt->data, pkt->size);

  958.             pkt->destruct = dstr;

  959.             pkt->flags |= AV_PKT_FLAG_KEY;

  960.             if (size < 0)

  961.                 av_free_packet(pkt);

  962.         } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE

  963.                    && !st->codec->codec_tag && read_gab2_sub(st, pkt)) {

  964.             ast->frame_offset++;

  965.             avi->stream_index = -1;

  966.             ast->remaining = 0;

  967.             goto resync;

  968.         } else {

  969.             /* XXX: How to handle B-frames in AVI? */

  970.             pkt->dts = ast->frame_offset;

  971. //                pkt->dts += ast->start;

  972.             if(ast->sample_size)

  973.                 pkt->dts /= ast->sample_size;

  974. //av_log(s, AV_LOG_DEBUG, "dts:%"PRId64" offset:%"PRId64" %d/%d smpl_siz:%d base:%d st:%d size:%d\n", pkt->dts, ast->frame_offset, ast->scale, ast->rate, ast->sample_size, AV_TIME_BASE, avi->stream_index, size);

  975.             pkt->stream_index = avi->stream_index;

  976. 

  977.             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

  978.                 AVIndexEntry *e;

  979.                 int index;

  980.                 assert(st->index_entries);

  981. 

  982.                 index= av_index_search_timestamp(st, ast->frame_offset, 0);

  983.                 e= &st->index_entries[index];

  984. 

  985.                 if(index >= 0 && e->timestamp == ast->frame_offset){

  986.                     if (e->flags & AVINDEX_KEYFRAME)

  987.                         pkt->flags |= AV_PKT_FLAG_KEY;

  988.                 }

  989.             } else {

  990.                 pkt->flags |= AV_PKT_FLAG_KEY;

  991.             }

  992.             ast->frame_offset += get_duration(ast, pkt->size);

  993.         }

  994.         ast->remaining -= size;

  995.         if(!ast->remaining){

  996.             avi->stream_index= -1;

  997.             ast->packet_size= 0;

  998.         }

  999. 

  1000.         if(!avi->non_interleaved && ast->seek_pos > pkt->pos){

  1001.             av_free_packet(pkt);

  1002.             goto resync;

  1003.         }

  1004.         ast->seek_pos= 0;

  1005. 

  1006.         return size;

  1007.     }

  1008. 

  1009.     memset(d, -1, sizeof(int)*8);

  1010.     for(i=sync=avio_tell(pb); !url_feof(pb); i++) {

  1011.         int j;

  1012. 

  1013.         for(j=0; j<7; j++)

  1014.             d[j]= d[j+1];

  1015.         d[7]= avio_r8(pb);

  1016. 

  1017.         size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);

  1018. 

  1019.         n= get_stream_idx(d+2);

  1020. //av_log(s, AV_LOG_DEBUG, "%X %X %X %X %X %X %X %X %"PRId64" %d %d\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);

  1021.         if(i + (uint64_t)size > avi->fsize || d[0]<0)

  1022.             continue;

  1023. 

  1024.         //parse ix##

  1025.         if(  (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)

  1026.         //parse JUNK

  1027.            ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')

  1028.            ||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){

  1029.             avio_skip(pb, size);

  1030. //av_log(s, AV_LOG_DEBUG, "SKIP\n");

  1031.             goto resync;

  1032.         }

  1033. 

  1034.         //parse stray LIST

  1035.         if(d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T'){

  1036.             avio_skip(pb, 4);

  1037.             goto resync;

  1038.         }

  1039. 

  1040.         n= get_stream_idx(d);

  1041. 

  1042.         if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)

  1043.             continue;

  1044. 

  1045.         //detect ##ix chunk and skip

  1046.         if(d[2] == 'i' && d[3] == 'x' && n < s->nb_streams){

  1047.             avio_skip(pb, size);

  1048.             goto resync;

  1049.         }

  1050. 

  1051.         //parse ##dc/##wb

  1052.         if(n < s->nb_streams){

  1053.             AVStream *st;

  1054.             AVIStream *ast;

  1055.             st = s->streams[n];

  1056.             ast = st->priv_data;

  1057. 

  1058.             if(s->nb_streams>=2){

  1059.                 AVStream *st1  = s->streams[1];

  1060.                 AVIStream *ast1= st1->priv_data;

  1061.                 //workaround for broken small-file-bug402.avi

  1062.                 if(   d[2] == 'w' && d[3] == 'b'

  1063.                    && n==0

  1064.                    && st ->codec->codec_type == AVMEDIA_TYPE_VIDEO

  1065.                    && st1->codec->codec_type == AVMEDIA_TYPE_AUDIO

  1066.                    && ast->prefix == 'd'*256+'c'

  1067.                    && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)

  1068.                   ){

  1069.                     n=1;

  1070.                     st = st1;

  1071.                     ast = ast1;

  1072.                     av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");

  1073.                 }

  1074.             }

  1075. 

  1076. 

  1077.             if(   (st->discard >= AVDISCARD_DEFAULT && size==0)

  1078.                /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & AV_PKT_FLAG_KEY))*/ //FIXME needs a little reordering

  1079.                || st->discard >= AVDISCARD_ALL){

  1080.                 ast->frame_offset += get_duration(ast, size);

  1081.                 avio_skip(pb, size);

  1082.                 goto resync;

  1083.             }

  1084. 

  1085.             if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {

  1086.                 int k = avio_r8(pb);

  1087.                 int last = (k + avio_r8(pb) - 1) & 0xFF;

  1088. 

  1089.                 avio_rl16(pb); //flags

  1090. 

  1091.                 for (; k <= last; k++)

  1092.                     ast->pal[k] = avio_rb32(pb)>>8;// b + (g << 8) + (r << 16);

  1093.                 ast->has_pal= 1;

  1094.                 goto resync;

  1095.             } else if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||

  1096.                          d[2]*256+d[3] == ast->prefix /*||

  1097.                          (d[2] == 'd' && d[3] == 'c') ||

  1098.                          (d[2] == 'w' && d[3] == 'b')*/) {

  1099. 

  1100. //av_log(s, AV_LOG_DEBUG, "OK\n");

  1101.                 if(d[2]*256+d[3] == ast->prefix)

  1102.                     ast->prefix_count++;

  1103.                 else{

  1104.                     ast->prefix= d[2]*256+d[3];

  1105.                     ast->prefix_count= 0;

  1106.                 }

  1107. 

  1108.                 avi->stream_index= n;

  1109.                 ast->packet_size= size + 8;

  1110.                 ast->remaining= size;

  1111. 

  1112.                 if(size || !ast->sample_size){

  1113.                     uint64_t pos= avio_tell(pb) - 8;

  1114.                     if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){

  1115.                         av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);

  1116.                     }

  1117.                 }

  1118.                 goto resync;

  1119.             }

  1120.         }

  1121.     }

  1122. 

  1123.     return AVERROR_EOF;

  1124. }

  1125. 

  1126. /* XXX: We make the implicit supposition that the positions are sorted

  1127.    for each stream. */

  1128. static int avi_read_idx1(AVFormatContext *s, int size)

  1129. {

  1130.     AVIContext *avi = s->priv_data;

  1131.     AVIOContext *pb = s->pb;

  1132.     int nb_index_entries, i;

  1133.     AVStream *st;

  1134.     AVIStream *ast;

  1135.     unsigned int index, tag, flags, pos, len;

  1136.     unsigned last_pos= -1;

  1137. 

  1138.     nb_index_entries = size / 16;

  1139.     if (nb_index_entries <= 0)

  1140.         return -1;

  1141. 

  1142.     /* Read the entries and sort them in each stream component. */

  1143.     for(i = 0; i < nb_index_entries; i++) {

  1144.         tag = avio_rl32(pb);

  1145.         flags = avio_rl32(pb);

  1146.         pos = avio_rl32(pb);

  1147.         len = avio_rl32(pb);

  1148. #if defined(DEBUG_SEEK)

  1149.         av_log(s, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",

  1150.                i, tag, flags, pos, len);

  1151. #endif

  1152.         if(i==0 && pos > avi->movi_list)

  1153.             avi->movi_list= 0; //FIXME better check

  1154.         pos += avi->movi_list;

  1155. 

  1156.         index = ((tag & 0xff) - '0') * 10;

  1157.         index += ((tag >> 8) & 0xff) - '0';

  1158.         if (index >= s->nb_streams)

  1159.             continue;

  1160.         st = s->streams[index];

  1161.         ast = st->priv_data;

  1162. 

  1163. #if defined(DEBUG_SEEK)

  1164.         av_log(s, AV_LOG_DEBUG, "%d cum_len=%"PRId64"\n", len, ast->cum_len);

  1165. #endif

  1166.         if(url_feof(pb))

  1167.             return -1;

  1168. 

  1169.         if(last_pos == pos)

  1170.             avi->non_interleaved= 1;

  1171.         else if(len || !ast->sample_size)

  1172.             av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);

  1173.         ast->cum_len += get_duration(ast, len);

  1174.         last_pos= pos;

  1175.     }

  1176.     return 0;

  1177. }

  1178. 

  1179. static int guess_ni_flag(AVFormatContext *s){

  1180.     int i;

  1181.     int64_t last_start=0;

  1182.     int64_t first_end= INT64_MAX;

  1183.     int64_t oldpos= avio_tell(s->pb);

  1184. 

  1185.     for(i=0; i<s->nb_streams; i++){

  1186.         AVStream *st = s->streams[i];

  1187.         int n= st->nb_index_entries;

  1188.         unsigned int size;

  1189. 

  1190.         if(n <= 0)

  1191.             continue;

  1192. 

  1193.         if(n >= 2){

  1194.             int64_t pos= st->index_entries[0].pos;

  1195.             avio_seek(s->pb, pos + 4, SEEK_SET);

  1196.             size= avio_rl32(s->pb);

  1197.             if(pos + size > st->index_entries[1].pos)

  1198.                 last_start= INT64_MAX;

  1199.         }

  1200. 

  1201.         if(st->index_entries[0].pos > last_start)

  1202.             last_start= st->index_entries[0].pos;

  1203.         if(st->index_entries[n-1].pos < first_end)

  1204.             first_end= st->index_entries[n-1].pos;

  1205.     }

  1206.     avio_seek(s->pb, oldpos, SEEK_SET);

  1207.     return last_start > first_end;

  1208. }

  1209. 

  1210. static int avi_load_index(AVFormatContext *s)

  1211. {

  1212.     AVIContext *avi = s->priv_data;

  1213.     AVIOContext *pb = s->pb;

  1214.     uint32_t tag, size;

  1215.     int64_t pos= avio_tell(pb);

  1216.     int ret = -1;

  1217. 

  1218.     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)

  1219.         goto the_end; // maybe truncated file

  1220. #ifdef DEBUG_SEEK

  1221.     printf("movi_end=0x%"PRIx64"\n", avi->movi_end);

  1222. #endif

  1223.     for(;;) {

  1224.         if (url_feof(pb))

  1225.             break;

  1226.         tag = avio_rl32(pb);

  1227.         size = avio_rl32(pb);

  1228. #ifdef DEBUG_SEEK

  1229.         printf("tag=%c%c%c%c size=0x%x\n",

  1230.                tag & 0xff,

  1231.                (tag >> 8) & 0xff,

  1232.                (tag >> 16) & 0xff,

  1233.                (tag >> 24) & 0xff,

  1234.                size);

  1235. #endif

  1236.         switch(tag) {

  1237.         case MKTAG('i', 'd', 'x', '1'):

  1238.             if (avi_read_idx1(s, size) < 0)

  1239.                 goto skip;

  1240.             ret = 0;

  1241.                 goto the_end;

  1242.             break;

  1243.         default:

  1244.         skip:

  1245.             size += (size & 1);

  1246.             if (avio_skip(pb, size) < 0)

  1247.                 goto the_end; // something is wrong here

  1248.             break;

  1249.         }

  1250.     }

  1251.  the_end:

  1252.     avio_seek(pb, pos, SEEK_SET);

  1253.     return ret;

  1254. }

  1255. 

  1256. static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)

  1257. {

  1258.     AVIStream *ast2 = st2->priv_data;

  1259.     int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);

  1260.     av_free_packet(&ast2->sub_pkt);

  1261.     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||

  1262.         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)

  1263.         av_read_packet(ast2->sub_ctx, &ast2->sub_pkt);

  1264. }

  1265. 

  1266. static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

  1267. {

  1268.     AVIContext *avi = s->priv_data;

  1269.     AVStream *st;

  1270.     int i, index;

  1271.     int64_t pos, pos_min;

  1272.     AVIStream *ast;

  1273. 

  1274.     if (!avi->index_loaded) {

  1275.         /* we only load the index on demand */

  1276.         avi_load_index(s);

  1277.         avi->index_loaded = 1;

  1278.     }

  1279.     assert(stream_index>= 0);

  1280. 

  1281.     st = s->streams[stream_index];

  1282.     ast= st->priv_data;

  1283.     index= av_index_search_timestamp(st, timestamp * FFMAX(ast->sample_size, 1), flags);

  1284.     if(index<0)

  1285.         return -1;

  1286. 

  1287.     /* find the position */

  1288.     pos = st->index_entries[index].pos;

  1289.     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);

  1290. 

  1291. //    av_log(s, AV_LOG_DEBUG, "XX %"PRId64" %d %"PRId64"\n", timestamp, index, st->index_entries[index].timestamp);

  1292. 

  1293.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1294.         /* One and only one real stream for DV in AVI, and it has video  */

  1295.         /* offsets. Calling with other stream indexes should have failed */

  1296.         /* the av_index_search_timestamp call above.                     */

  1297.         assert(stream_index == 0);

  1298. 

  1299.         /* Feed the DV video stream version of the timestamp to the */

  1300.         /* DV demux so it can synthesize correct timestamps.        */

  1301.         dv_offset_reset(avi->dv_demux, timestamp);

  1302. 

  1303.         avio_seek(s->pb, pos, SEEK_SET);

  1304.         avi->stream_index= -1;

  1305.         return 0;

  1306.     }

  1307. 

  1308.     pos_min= pos;

  1309.     for(i = 0; i < s->nb_streams; i++) {

  1310.         AVStream *st2 = s->streams[i];

  1311.         AVIStream *ast2 = st2->priv_data;

  1312. 

  1313.         ast2->packet_size=

  1314.         ast2->remaining= 0;

  1315. 

  1316.         if (ast2->sub_ctx) {

  1317.             seek_subtitle(st, st2, timestamp);

  1318.             continue;

  1319.         }

  1320. 

  1321.         if (st2->nb_index_entries <= 0)

  1322.             continue;

  1323. 

  1324. //        assert(st2->codec->block_align);

  1325.         assert((int64_t)st2->time_base.num*ast2->rate == (int64_t)st2->time_base.den*ast2->scale);

  1326.         index = av_index_search_timestamp(

  1327.                 st2,

  1328.                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),

  1329.                 flags | AVSEEK_FLAG_BACKWARD);

  1330.         if(index<0)

  1331.             index=0;

  1332.         ast2->seek_pos= st2->index_entries[index].pos;

  1333.         pos_min= FFMIN(pos_min,ast2->seek_pos);

  1334.         ast2->frame_offset = st2->index_entries[index].timestamp;

  1335.     }

  1336. 

  1337.     /* do the seek */

  1338.     avio_seek(s->pb, pos_min, SEEK_SET);

  1339.     avi->stream_index= -1;

  1340.     return 0;

  1341. }

  1342. 

  1343. static int avi_read_close(AVFormatContext *s)

  1344. {

  1345.     int i;

  1346.     AVIContext *avi = s->priv_data;

  1347. 

  1348.     for(i=0;i<s->nb_streams;i++) {

  1349.         AVStream *st = s->streams[i];

  1350.         AVIStream *ast = st->priv_data;

  1351.         if (ast) {

  1352.             if (ast->sub_ctx) {

  1353.                 av_freep(&ast->sub_ctx->pb);

  1354.                 av_close_input_stream(ast->sub_ctx);

  1355.             }

  1356.             av_free(ast->sub_buffer);

  1357.             av_free_packet(&ast->sub_pkt);

  1358.         }

  1359.     }

  1360. 

  1361.     av_free(avi->dv_demux);

  1362. 

  1363.     return 0;

  1364. }

  1365. 

  1366. static int avi_probe(AVProbeData *p)

  1367. {

  1368.     int i;

  1369. 

  1370.     /* check file header */

  1371.     for(i=0; avi_headers[i][0]; i++)

  1372.         if(!memcmp(p->buf  , avi_headers[i]  , 4) &&

  1373.            !memcmp(p->buf+8, avi_headers[i]+4, 4))

  1374.             return AVPROBE_SCORE_MAX;

  1375. 

  1376.     return 0;

  1377. }

  1378. 

  1379. AVInputFormat ff_avi_demuxer = {

  1380.     "avi",

  1381.     NULL_IF_CONFIG_SMALL("AVI format"),

  1382.     sizeof(AVIContext),

  1383.     avi_probe,

  1384.     avi_read_header,

  1385.     avi_read_packet,

  1386.     avi_read_close,

  1387.     avi_read_seek,

  1388. };