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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. #include "libavutil/intreadwrite.h"

  23. #include "libavutil/mathematics.h"

  24. #include "libavutil/bswap.h"

  25. #include "libavutil/opt.h"

  26. #include "libavutil/dict.h"

  27. #include "libavutil/avstring.h"

  28. #include "libavutil/avassert.h"

  29. #include "avformat.h"

  30. #include "internal.h"

  31. #include "avi.h"

  32. #include "dv.h"

  33. #include "riff.h"

  34. 

  35. typedef struct AVIStream {

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

  37.                          (used to compute the pts) */

  38.     int remaining;

  39.     int packet_size;

  40. 

  41.     uint32_t scale;

  42.     uint32_t rate;

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

  44. 

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

  46. 

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

  48.     int prefix_count;

  49.     uint32_t pal[256];

  50.     int has_pal;

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

  52. 

  53.     AVFormatContext *sub_ctx;

  54.     AVPacket sub_pkt;

  55.     uint8_t *sub_buffer;

  56. 

  57.     int64_t seek_pos;

  58. } AVIStream;

  59. 

  60. typedef struct {

  61.     const AVClass *class;

  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.     int use_odml;

  74. #define MAX_ODML_DEPTH 1000

  75.     int64_t dts_max;

  76. } AVIContext;

  77. 

  78. 

  79. static const AVOption options[] = {

  80.     { "use_odml", "use odml index", offsetof(AVIContext, use_odml), AV_OPT_TYPE_INT, {.dbl = 1}, -1, 1, AV_OPT_FLAG_DECODING_PARAM},

  81.     { NULL },

  82. };

  83. 

  84. static const AVClass demuxer_class = {

  85.     .class_name = "avi",

  86.     .item_name  = av_default_item_name,

  87.     .option     = options,

  88.     .version    = LIBAVUTIL_VERSION_INT,

  89.     .category   = AV_CLASS_CATEGORY_DEMUXER,

  90. };

  91. 

  92. 

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

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

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

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

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

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

  99.     { 0 }

  100. };

  101. 

  102. static const AVMetadataConv avi_metadata_conv[] = {

  103.     { "strn", "title" },

  104.     { 0 },

  105. };

  106. 

  107. static int avi_load_index(AVFormatContext *s);

  108. static int guess_ni_flag(AVFormatContext *s);

  109. 

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

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

  112.            str, tag & 0xff,                             \

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

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

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

  116.            size)

  117. 

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

  119.     if(ast->sample_size){

  120.         return len;

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

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

  123.     }else

  124.         return 1;

  125. }

  126. 

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

  128. {

  129.     AVIContext *avi = s->priv_data;

  130.     char header[8];

  131.     int i;

  132. 

  133.     /* check RIFF header */

  134.     avio_read(pb, header, 4);

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

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

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

  138. 

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

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

  141.             break;

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

  143.         return -1;

  144. 

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

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

  147. 

  148.     return 0;

  149. }

  150. 

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

  152.     AVIContext *avi = s->priv_data;

  153.     AVIOContext *pb = s->pb;

  154.     int longs_pre_entry= avio_rl16(pb);

  155.     int index_sub_type = avio_r8(pb);

  156.     int index_type     = avio_r8(pb);

  157.     int entries_in_use = avio_rl32(pb);

  158.     int chunk_id       = avio_rl32(pb);

  159.     int64_t base       = avio_rl64(pb);

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

  161.     AVStream *st;

  162.     AVIStream *ast;

  163.     int i;

  164.     int64_t last_pos= -1;

  165.     int64_t filesize= avi->fsize;

  166. 

  167.     av_dlog(s, "longs_pre_entry:%d index_type:%d entries_in_use:%d chunk_id:%X base:%16"PRIX64"\n",

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

  169. 

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

  171.         return -1;

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

  173.     ast = st->priv_data;

  174. 

  175.     if(index_sub_type)

  176.         return -1;

  177. 

  178.     avio_rl32(pb);

  179. 

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

  181.         return -1;

  182.     if(index_type>1)

  183.         return -1;

  184. 

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

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

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

  188.             base &= 0xFFFFFFFF;

  189.         else

  190.             return -1;

  191.     }

  192. 

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

  194.         if(index_type){

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

  196.             int len    = avio_rl32(pb);

  197.             int key= len >= 0;

  198.             len &= 0x7FFFFFFF;

  199. 

  200. #ifdef DEBUG_SEEK

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

  202. #endif

  203.             if(url_feof(pb))

  204.                 return -1;

  205. 

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

  207.                 avi->non_interleaved= 1;

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

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

  210. 

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

  212.             last_pos= pos;

  213.         }else{

  214.             int64_t offset, pos;

  215.             int duration;

  216.             offset = avio_rl64(pb);

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

  218.             duration = avio_rl32(pb);

  219. 

  220.             if(url_feof(pb))

  221.                 return -1;

  222. 

  223.             pos = avio_tell(pb);

  224. 

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

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

  227.                 return -1;

  228.             }

  229. 

  230.             if(avio_seek(pb, offset+8, SEEK_SET) < 0)

  231.                 return -1;

  232.             avi->odml_depth++;

  233.             read_braindead_odml_indx(s, frame_num);

  234.             avi->odml_depth--;

  235.             frame_num += duration;

  236. 

  237.             if(avio_seek(pb, pos, SEEK_SET) < 0) {

  238.                 av_log(s, AV_LOG_ERROR, "Failed to restore position after reading index");

  239.                 return -1;

  240.             }

  241. 

  242.         }

  243.     }

  244.     avi->index_loaded=2;

  245.     return 0;

  246. }

  247. 

  248. static void clean_index(AVFormatContext *s){

  249.     int i;

  250.     int64_t j;

  251. 

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

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

  254.         AVIStream *ast = st->priv_data;

  255.         int n= st->nb_index_entries;

  256.         int max= ast->sample_size;

  257.         int64_t pos, size, ts;

  258. 

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

  260.             continue;

  261. 

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

  263. 

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

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

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

  267. 

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

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

  270.         }

  271.     }

  272. }

  273. 

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

  275. {

  276.     AVIOContext *pb = s->pb;

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

  278. 

  279.     size += (size & 1);

  280. 

  281.     if (size == UINT_MAX)

  282.         return -1;

  283.     value = av_malloc(size+1);

  284.     if (!value)

  285.         return -1;

  286.     avio_read(pb, value, size);

  287.     value[size]=0;

  288. 

  289.     AV_WL32(key, tag);

  290. 

  291.     return av_dict_set(st ? &st->metadata : &s->metadata, key, value,

  292.                             AV_DICT_DONT_STRDUP_VAL);

  293. }

  294. 

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

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

  297. 

  298. static void avi_metadata_creation_time(AVDictionary **metadata, char *date)

  299. {

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

  301.     int i, day, year;

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

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

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

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

  306.             if (!av_strcasecmp(month, months[i])) {

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

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

  309.                 av_dict_set(metadata, "creation_time", buffer, 0);

  310.             }

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

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

  313.         av_dict_set(metadata, "creation_time", date, 0);

  314.     }

  315. }

  316. 

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

  318. {

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

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

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

  322.         switch (tag) {

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

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

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

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

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

  328.                 const char *name = NULL;

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

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

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

  332.                 switch (tag) {

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

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

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

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

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

  338.                     break;

  339.                 }

  340.                 if (name)

  341.                     av_dict_set(&s->metadata, name, buffer, 0);

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

  343.             }

  344.             break;

  345.         }

  346.         default:

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

  348.             break;

  349.         }

  350.     }

  351. }

  352. 

  353. static int avi_read_header(AVFormatContext *s)

  354. {

  355.     AVIContext *avi = s->priv_data;

  356.     AVIOContext *pb = s->pb;

  357.     unsigned int tag, tag1, handler;

  358.     int codec_type, stream_index, frame_period;

  359.     unsigned int size;

  360.     int i;

  361.     AVStream *st;

  362.     AVIStream *ast = NULL;

  363.     int avih_width=0, avih_height=0;

  364.     int amv_file_format=0;

  365.     uint64_t list_end = 0;

  366.     int ret;

  367. 

  368.     avi->stream_index= -1;

  369. 

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

  371.         return -1;

  372. 

  373.     av_log(avi, AV_LOG_DEBUG, "use odml:%d\n", avi->use_odml);

  374. 

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

  376.     if(avi->fsize<=0 || avi->fsize < avi->riff_end)

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

  378. 

  379.     /* first list tag */

  380.     stream_index = -1;

  381.     codec_type = -1;

  382.     frame_period = 0;

  383.     for(;;) {

  384.         if (url_feof(pb))

  385.             goto fail;

  386.         tag = avio_rl32(pb);

  387.         size = avio_rl32(pb);

  388. 

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

  390. 

  391.         switch(tag) {

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

  393.             list_end = avio_tell(pb) + size;

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

  395.             tag1 = avio_rl32(pb);

  396. 

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

  398. 

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

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

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

  402.                 else     avi->movi_end = avi->fsize;

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

  404.                 goto end_of_header;

  405.             }

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

  407.                 ff_read_riff_info(s, size - 4);

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

  409.                 avi_read_nikon(s, list_end);

  410. 

  411.             break;

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

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

  414.             size += (size & 1);

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

  416.             avio_skip(pb, size);

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

  418.             break;

  419.         }

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

  421.             avi->is_odml = 1;

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

  423.             break;

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

  425.             amv_file_format=1;

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

  427.             /* AVI header */

  428.             /* using frame_period is bad idea */

  429.             frame_period = avio_rl32(pb);

  430.             avio_rl32(pb); /* max. bytes per second */

  431.             avio_rl32(pb);

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

  433. 

  434.             avio_skip(pb, 2 * 4);

  435.             avio_rl32(pb);

  436.             avio_rl32(pb);

  437.             avih_width=avio_rl32(pb);

  438.             avih_height=avio_rl32(pb);

  439. 

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

  441.             break;

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

  443.             /* stream header */

  444. 

  445.             tag1 = avio_rl32(pb);

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

  447. 

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

  449.                 avio_skip(pb, size - 8);

  450.                 break;

  451.             }else{

  452.                 stream_index++;

  453.                 st = avformat_new_stream(s, NULL);

  454.                 if (!st)

  455.                     goto fail;

  456. 

  457.                 st->id = stream_index;

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

  459.                 if (!ast)

  460.                     goto fail;

  461.                 st->priv_data = ast;

  462.             }

  463.             if(amv_file_format)

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

  465. 

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

  467. 

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

  469.                 int64_t dv_dur;

  470. 

  471.                 /*

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

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

  474.                  */

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

  476.                     goto fail;

  477. 

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

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

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

  481.                    goto fail;

  482. 

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

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

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

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

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

  488.                 s->nb_streams = 0;

  489.                 if (CONFIG_DV_DEMUXER) {

  490.                     avi->dv_demux = avpriv_dv_init_demux(s);

  491.                     if (!avi->dv_demux)

  492.                         goto fail;

  493.                 }

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

  495.                 avio_skip(pb, 3 * 4);

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

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

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

  499. 

  500.                 dv_dur = avio_rl32(pb);

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

  502.                     dv_dur *= AV_TIME_BASE;

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

  504.                 }

  505.                 /*

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

  507.                  *      will make a guess based on bitrate.

  508.                  */

  509. 

  510.                 stream_index = s->nb_streams - 1;

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

  512.                 break;

  513.             }

  514. 

  515.             av_assert0(stream_index < s->nb_streams);

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

  517. 

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

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

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

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

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

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

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

  525.                 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);

  526.                 if(frame_period){

  527.                     ast->rate = 1000000;

  528.                     ast->scale = frame_period;

  529.                 }else{

  530.                     ast->rate = 25;

  531.                     ast->scale = 1;

  532.                 }

  533.             }

  534.             avpriv_set_pts_info(st, 64, ast->scale, ast->rate);

  535. 

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

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

  538. 

  539.             st->start_time = 0;

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

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

  542.             if (ast->cum_len*ast->scale/ast->rate > 3600) {

  543.                 av_log(s, AV_LOG_ERROR, "crazy start time, iam scared, giving up\n");

  544.                 return AVERROR_INVALIDDATA;

  545.             }

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

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

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

  549. 

  550.             switch(tag1) {

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

  552.                 codec_type = AVMEDIA_TYPE_VIDEO;

  553. 

  554.                 ast->sample_size = 0;

  555.                 break;

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

  557.                 codec_type = AVMEDIA_TYPE_AUDIO;

  558.                 break;

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

  560.                 codec_type = AVMEDIA_TYPE_SUBTITLE;

  561.                 break;

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

  563.                 codec_type = AVMEDIA_TYPE_DATA;

  564.                 break;

  565.             default:

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

  567.             }

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

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

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

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

  572.             break;

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

  574.             /* stream header */

  575.             if (!size)

  576.                 break;

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

  578.                 avio_skip(pb, size);

  579.             } else {

  580.                 uint64_t cur_pos = avio_tell(pb);

  581.                 unsigned esize;

  582.                 if (cur_pos < list_end)

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

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

  585.                 switch(codec_type) {

  586.                 case AVMEDIA_TYPE_VIDEO:

  587.                     if(amv_file_format){

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

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

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

  591.                         st->codec->codec_id = AV_CODEC_ID_AMV;

  592.                         avio_skip(pb, size);

  593.                         break;

  594.                     }

  595.                     tag1 = ff_get_bmp_header(pb, st, &esize);

  596. 

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

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

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

  600.                         st->codec->codec_id = AV_CODEC_ID_XSUB;

  601.                         break;

  602.                     }

  603. 

  604.                     if(size > 10*4 && size<(1<<30) && size < avi->fsize){

  605.                         if(esize == size-1 && (esize&1)) st->codec->extradata_size= esize - 10*4;

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

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

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

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

  610.                             return AVERROR(ENOMEM);

  611.                         }

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

  613.                     }

  614. 

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

  616.                         avio_r8(pb);

  617. 

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

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

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

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

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

  623.                         const uint8_t *pal_src;

  624. 

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

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

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

  628.                             ast->pal[i] = 0xFF<<24 | AV_RL32(pal_src+4*i);

  629.                         ast->has_pal = 1;

  630.                     }

  631. 

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

  633. 

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

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

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

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

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

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

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

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

  642.                         st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;

  643. 

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

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

  646.                         st->codec->extradata= av_realloc_f(st->codec->extradata, 1, st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);

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

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

  649.                     }

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

  651. 

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

  653.                     break;

  654.                 case AVMEDIA_TYPE_AUDIO:

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

  656.                     if (ret < 0)

  657.                         return ret;

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

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

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

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

  662.                     }

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

  664.                         avio_skip(pb, 1);

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

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

  667.                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;

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

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

  670.                      * fail. */

  671.                     if (st->codec->codec_id == AV_CODEC_ID_AAC && st->codec->extradata_size)

  672.                         st->need_parsing = AVSTREAM_PARSE_NONE;

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

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

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

  676.                         st->codec->codec_id  = AV_CODEC_ID_XAN_DPCM;

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

  678.                         ast->dshow_block_align = 0;

  679.                     }

  680.                     if (amv_file_format){

  681.                         st->codec->codec_id  = AV_CODEC_ID_ADPCM_IMA_AMV;

  682.                         ast->dshow_block_align = 0;

  683.                     }

  684.                     break;

  685.                 case AVMEDIA_TYPE_SUBTITLE:

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

  687.                     st->request_probe= 1;

  688.                     break;

  689.                 default:

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

  691.                     st->codec->codec_id= AV_CODEC_ID_NONE;

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

  693.                     avio_skip(pb, size);

  694.                     break;

  695.                 }

  696.             }

  697.             break;

  698.         case MKTAG('s', 't', 'r', 'd'):

  699.             if (stream_index >= (unsigned)s->nb_streams || s->streams[stream_index]->codec->extradata_size) {

  700.                 avio_skip(pb, size);

  701.             } else {

  702.                 uint64_t cur_pos = avio_tell(pb);

  703.                 if (cur_pos < list_end)

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

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

  706. 

  707.                 if(size<(1<<30)){

  708.                     st->codec->extradata_size= size;

  709.                     st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);

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

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

  712.                         return AVERROR(ENOMEM);

  713.                     }

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

  715.                 }

  716. 

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

  718.                     avio_r8(pb);

  719.             }

  720.             break;

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

  722.             i= avio_tell(pb);

  723.             if(pb->seekable && !(s->flags & AVFMT_FLAG_IGNIDX) && avi->use_odml &&

  724.                read_braindead_odml_indx(s, 0) < 0 && (s->error_recognition & AV_EF_EXPLODE))

  725.                 goto fail;

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

  727.             break;

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

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

  730.                 AVRational active, active_aspect;

  731. 

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

  733.                 avio_rl32(pb);

  734.                 avio_rl32(pb);

  735.                 avio_rl32(pb);

  736.                 avio_rl32(pb);

  737.                 avio_rl32(pb);

  738. 

  739.                 active_aspect.den= avio_rl16(pb);

  740.                 active_aspect.num= avio_rl16(pb);

  741.                 active.num       = avio_rl32(pb);

  742.                 active.den       = avio_rl32(pb);

  743.                 avio_rl32(pb); //nbFieldsPerFrame

  744. 

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

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

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

  748.                 }

  749.                 size -= 9*4;

  750.             }

  751.             avio_skip(pb, size);

  752.             break;

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

  754.             if(s->nb_streams){

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

  756.                 break;

  757.             }

  758.         default:

  759.             if(size > 1000000){

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

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

  762.                 if (s->error_recognition & AV_EF_EXPLODE)

  763.                     goto fail;

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

  765.                 avi->movi_end  = avi->fsize;

  766.                 goto end_of_header;

  767.             }

  768.             /* skip tag */

  769.             size += (size & 1);

  770.             avio_skip(pb, size);

  771.             break;

  772.         }

  773.     }

  774.  end_of_header:

  775.     /* check stream number */

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

  777.     fail:

  778.         return -1;

  779.     }

  780. 

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

  782.         avi_load_index(s);

  783.     avi->index_loaded |= 1;

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

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

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

  787.         if(st->nb_index_entries)

  788.             break;

  789.     }

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

  791.     // a mis-detection.

  792.     if(avi->dv_demux)

  793.         avi->non_interleaved=0;

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

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

  796.         avi->non_interleaved=0;

  797.     }

  798. 

  799.     if(avi->non_interleaved) {

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

  801.         clean_index(s);

  802.     }

  803. 

  804.     ff_metadata_conv_ctx(s, NULL, avi_metadata_conv);

  805.     ff_metadata_conv_ctx(s, NULL, ff_riff_info_conv);

  806. 

  807.     return 0;

  808. }

  809. 

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

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

  812.         uint8_t desc[256];

  813.         int score = AVPROBE_SCORE_MAX / 2, ret;

  814.         AVIStream *ast = st->priv_data;

  815.         AVInputFormat *sub_demuxer;

  816.         AVRational time_base;

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

  818.                                               pkt->size - 7,

  819.                                               0, NULL, NULL, NULL, NULL);

  820.         AVProbeData pd;

  821.         unsigned int desc_len = avio_rl32(pb);

  822. 

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

  824.             goto error;

  825. 

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

  827.         avio_skip(pb, desc_len - ret);

  828.         if (*desc)

  829.             av_dict_set(&st->metadata, "title", desc, 0);

  830. 

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

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

  833. 

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

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

  836.             goto error;

  837. 

  838.         if (!(ast->sub_ctx = avformat_alloc_context()))

  839.             goto error;

  840. 

  841.         ast->sub_ctx->pb      = pb;

  842.         if (!avformat_open_input(&ast->sub_ctx, "", sub_demuxer, NULL)) {

  843.             ff_read_packet(ast->sub_ctx, &ast->sub_pkt);

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

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

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

  847.             avpriv_set_pts_info(st, 64, time_base.num, time_base.den);

  848.         }

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

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

  851.         return 1;

  852. error:

  853.         av_freep(&pb);

  854.     }

  855.     return 0;

  856. }

  857. 

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

  859.                                   AVPacket *pkt)

  860. {

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

  862.     int64_t ts, next_ts, ts_min = INT64_MAX;

  863.     AVStream *st, *sub_st = NULL;

  864.     int i;

  865. 

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

  867.                            AV_TIME_BASE_Q);

  868. 

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

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

  871.         ast = st->priv_data;

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

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

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

  875.                 ts_min = ts;

  876.                 sub_st = st;

  877.             }

  878.         }

  879.     }

  880. 

  881.     if (sub_st) {

  882.         ast = sub_st->priv_data;

  883.         *pkt = ast->sub_pkt;

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

  885.         if (ff_read_packet(ast->sub_ctx, &ast->sub_pkt) < 0)

  886.             ast->sub_pkt.data = NULL;

  887.     }

  888.     return sub_st;

  889. }

  890. 

  891. static int get_stream_idx(int *d){

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

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

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

  895.     }else{

  896.         return 100; //invalid stream ID

  897.     }

  898. }

  899. 

  900. /**

  901.  *

  902.  * @param exit_early set to 1 to just gather packet position without making the changes needed to actually read & return the packet

  903.  */

  904. static int avi_sync(AVFormatContext *s, int exit_early)

  905. {

  906.     AVIContext *avi = s->priv_data;

  907.     AVIOContext *pb = s->pb;

  908.     int n;

  909.     unsigned int d[8];

  910.     unsigned int size;

  911.     int64_t i, sync;

  912. 

  913. start_sync:

  914.     memset(d, -1, sizeof(d));

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

  916.         int j;

  917. 

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

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

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

  921. 

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

  923. 

  924.         n= get_stream_idx(d+2);

  925. //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);

  926.         if(i + (uint64_t)size > avi->fsize || d[0] > 127)

  927.             continue;

  928. 

  929.         //parse ix##

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

  931.         //parse JUNK

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

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

  934.             avio_skip(pb, size);

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

  936.             goto start_sync;

  937.         }

  938. 

  939.         //parse stray LIST

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

  941.             avio_skip(pb, 4);

  942.             goto start_sync;

  943.         }

  944. 

  945.         n= get_stream_idx(d);

  946. 

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

  948.             continue;

  949. 

  950.         //detect ##ix chunk and skip

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

  952.             avio_skip(pb, size);

  953.             goto start_sync;

  954.         }

  955. 

  956.         //parse ##dc/##wb

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

  958.             AVStream *st;

  959.             AVIStream *ast;

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

  961.             ast = st->priv_data;

  962. 

  963.             if (!ast) {

  964.                 av_log(s, AV_LOG_WARNING, "Skiping foreign stream %d packet\n", n);

  965.                 continue;

  966.             }

  967. 

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

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

  970.                 AVIStream *ast1= st1->priv_data;

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

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

  973.                    && n==0

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

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

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

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

  978.                   ){

  979.                     n=1;

  980.                     st = st1;

  981.                     ast = ast1;

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

  983.                 }

  984.             }

  985. 

  986. 

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

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

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

  990.                 if (!exit_early) {

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

  992.                 }

  993.                 avio_skip(pb, size);

  994.                 goto start_sync;

  995.             }

  996. 

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

  998.                 int k = avio_r8(pb);

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

  1000. 

  1001.                 avio_rl16(pb); //flags

  1002. 

  1003.                 for (; k <= last; k++)

  1004.                     ast->pal[k] = 0xFF<<24 | avio_rb32(pb)>>8;// b + (g << 8) + (r << 16);

  1005.                 ast->has_pal= 1;

  1006.                 goto start_sync;

  1007.             } else if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||

  1008.                          d[2]*256+d[3] == ast->prefix /*||

  1009.                          (d[2] == 'd' && d[3] == 'c') ||

  1010.                          (d[2] == 'w' && d[3] == 'b')*/) {

  1011. 

  1012.                 if (exit_early)

  1013.                     return 0;

  1014. //av_log(s, AV_LOG_DEBUG, "OK\n");

  1015.                 if(d[2]*256+d[3] == ast->prefix)

  1016.                     ast->prefix_count++;

  1017.                 else{

  1018.                     ast->prefix= d[2]*256+d[3];

  1019.                     ast->prefix_count= 0;

  1020.                 }

  1021. 

  1022.                 avi->stream_index= n;

  1023.                 ast->packet_size= size + 8;

  1024.                 ast->remaining= size;

  1025. 

  1026.                 if(size || !ast->sample_size){

  1027.                     uint64_t pos= avio_tell(pb) - 8;

  1028.                     if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){

  1029.                         av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);

  1030.                     }

  1031.                 }

  1032.                 return 0;

  1033.             }

  1034.         }

  1035.     }

  1036. 

  1037.     if(pb->error)

  1038.         return pb->error;

  1039.     return AVERROR_EOF;

  1040. }

  1041. 

  1042. static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)

  1043. {

  1044.     AVIContext *avi = s->priv_data;

  1045.     AVIOContext *pb = s->pb;

  1046.     int err;

  1047.     void* dstr;

  1048. 

  1049.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1050.         int size = avpriv_dv_get_packet(avi->dv_demux, pkt);

  1051.         if (size >= 0)

  1052.             return size;

  1053.     }

  1054. 

  1055.     if(avi->non_interleaved){

  1056.         int best_stream_index = 0;

  1057.         AVStream *best_st= NULL;

  1058.         AVIStream *best_ast;

  1059.         int64_t best_ts= INT64_MAX;

  1060.         int i;

  1061. 

  1062.         for(i=0; i<s->nb_streams; i++){

  1063.             AVStream *st = s->streams[i];

  1064.             AVIStream *ast = st->priv_data;

  1065.             int64_t ts= ast->frame_offset;

  1066.             int64_t last_ts;

  1067. 

  1068.             if(!st->nb_index_entries)

  1069.                 continue;

  1070. 

  1071.             last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;

  1072.             if(!ast->remaining && ts > last_ts)

  1073.                 continue;

  1074. 

  1075.             ts = av_rescale_q(ts, st->time_base, (AVRational){FFMAX(1, ast->sample_size), AV_TIME_BASE});

  1076. 

  1077. //            av_log(s, AV_LOG_DEBUG, "%"PRId64" %d/%d %"PRId64"\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);

  1078.             if(ts < best_ts){

  1079.                 best_ts= ts;

  1080.                 best_st= st;

  1081.                 best_stream_index= i;

  1082.             }

  1083.         }

  1084.         if(!best_st)

  1085.             return AVERROR_EOF;

  1086. 

  1087.         best_ast = best_st->priv_data;

  1088.         best_ts = best_ast->frame_offset;

  1089.         if(best_ast->remaining)

  1090.             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);

  1091.         else{

  1092.             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);

  1093.             if(i>=0)

  1094.                 best_ast->frame_offset= best_st->index_entries[i].timestamp;

  1095.         }

  1096. 

  1097. //        av_log(s, AV_LOG_DEBUG, "%d\n", i);

  1098.         if(i>=0){

  1099.             int64_t pos= best_st->index_entries[i].pos;

  1100.             pos += best_ast->packet_size - best_ast->remaining;

  1101.             if(avio_seek(s->pb, pos + 8, SEEK_SET) < 0)

  1102.               return AVERROR_EOF;

  1103. //        av_log(s, AV_LOG_DEBUG, "pos=%"PRId64"\n", pos);

  1104. 

  1105.             av_assert0(best_ast->remaining <= best_ast->packet_size);

  1106. 

  1107.             avi->stream_index= best_stream_index;

  1108.             if(!best_ast->remaining)

  1109.                 best_ast->packet_size=

  1110.                 best_ast->remaining= best_st->index_entries[i].size;

  1111.         }

  1112.         else

  1113.           return AVERROR_EOF;

  1114.     }

  1115. 

  1116. resync:

  1117.     if(avi->stream_index >= 0){

  1118.         AVStream *st= s->streams[ avi->stream_index ];

  1119.         AVIStream *ast= st->priv_data;

  1120.         int size, err;

  1121. 

  1122.         if(get_subtitle_pkt(s, st, pkt))

  1123.             return 0;

  1124. 

  1125.         if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM

  1126.             size= INT_MAX;

  1127.         else if(ast->sample_size < 32)

  1128.             // arbitrary multiplier to avoid tiny packets for raw PCM data

  1129.             size= 1024*ast->sample_size;

  1130.         else

  1131.             size= ast->sample_size;

  1132. 

  1133.         if(size > ast->remaining)

  1134.             size= ast->remaining;

  1135.         avi->last_pkt_pos= avio_tell(pb);

  1136.         err= av_get_packet(pb, pkt, size);

  1137.         if(err<0)

  1138.             return err;

  1139.         size = err;

  1140. 

  1141.         if(ast->has_pal && pkt->data && pkt->size<(unsigned)INT_MAX/2){

  1142.             uint8_t *pal;

  1143.             pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE);

  1144.             if(!pal){

  1145.                 av_log(s, AV_LOG_ERROR, "Failed to allocate data for palette\n");

  1146.             }else{

  1147.                 memcpy(pal, ast->pal, AVPALETTE_SIZE);

  1148.                 ast->has_pal = 0;

  1149.             }

  1150.         }

  1151. 

  1152.         if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1153.             dstr = pkt->destruct;

  1154.             size = avpriv_dv_produce_packet(avi->dv_demux, pkt,

  1155.                                     pkt->data, pkt->size, pkt->pos);

  1156.             pkt->destruct = dstr;

  1157.             pkt->flags |= AV_PKT_FLAG_KEY;

  1158.             if (size < 0)

  1159.                 av_free_packet(pkt);

  1160.         } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE

  1161.                    && !st->codec->codec_tag && read_gab2_sub(st, pkt)) {

  1162.             ast->frame_offset++;

  1163.             avi->stream_index = -1;

  1164.             ast->remaining = 0;

  1165.             goto resync;

  1166.         } else {

  1167.             /* XXX: How to handle B-frames in AVI? */

  1168.             pkt->dts = ast->frame_offset;

  1169. //                pkt->dts += ast->start;

  1170.             if(ast->sample_size)

  1171.                 pkt->dts /= ast->sample_size;

  1172. //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);

  1173.             pkt->stream_index = avi->stream_index;

  1174. 

  1175.             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

  1176.                 AVIndexEntry *e;

  1177.                 int index;

  1178.                 av_assert0(st->index_entries);

  1179. 

  1180.                 index= av_index_search_timestamp(st, ast->frame_offset, 0);

  1181.                 e= &st->index_entries[index];

  1182. 

  1183.                 if(index >= 0 && e->timestamp == ast->frame_offset){

  1184.                     if (index == st->nb_index_entries-1){

  1185.                         int key=1;

  1186.                         int i;

  1187.                         uint32_t state=-1;

  1188.                         for(i=0; i<FFMIN(size,256); i++){

  1189.                             if(st->codec->codec_id == AV_CODEC_ID_MPEG4){

  1190.                                 if(state == 0x1B6){

  1191.                                     key= !(pkt->data[i]&0xC0);

  1192.                                     break;

  1193.                                 }

  1194.                             }else

  1195.                                 break;

  1196.                             state= (state<<8) + pkt->data[i];

  1197.                         }

  1198.                         if(!key)

  1199.                             e->flags &= ~AVINDEX_KEYFRAME;

  1200.                     }

  1201.                     if (e->flags & AVINDEX_KEYFRAME)

  1202.                         pkt->flags |= AV_PKT_FLAG_KEY;

  1203.                 }

  1204.             } else {

  1205.                 pkt->flags |= AV_PKT_FLAG_KEY;

  1206.             }

  1207.             ast->frame_offset += get_duration(ast, pkt->size);

  1208.         }

  1209.         ast->remaining -= size;

  1210.         if(!ast->remaining){

  1211.             avi->stream_index= -1;

  1212.             ast->packet_size= 0;

  1213.         }

  1214. 

  1215.         if(!avi->non_interleaved && pkt->pos >= 0 && ast->seek_pos > pkt->pos){

  1216.             av_free_packet(pkt);

  1217.             goto resync;

  1218.         }

  1219.         ast->seek_pos= 0;

  1220. 

  1221.         if(!avi->non_interleaved && st->nb_index_entries>1 && avi->index_loaded>1){

  1222.             int64_t dts= av_rescale_q(pkt->dts, st->time_base, AV_TIME_BASE_Q);

  1223. 

  1224.             if(avi->dts_max - dts > 2*AV_TIME_BASE){

  1225.                 avi->non_interleaved= 1;

  1226.                 av_log(s, AV_LOG_INFO, "Switching to NI mode, due to poor interleaving\n");

  1227.             }else if(avi->dts_max < dts)

  1228.                 avi->dts_max = dts;

  1229.         }

  1230. 

  1231.         return size;

  1232.     }

  1233. 

  1234.     if ((err = avi_sync(s, 0)) < 0)

  1235.         return err;

  1236.     goto resync;

  1237. }

  1238. 

  1239. /* XXX: We make the implicit supposition that the positions are sorted

  1240.    for each stream. */

  1241. static int avi_read_idx1(AVFormatContext *s, int size)

  1242. {

  1243.     AVIContext *avi = s->priv_data;

  1244.     AVIOContext *pb = s->pb;

  1245.     int nb_index_entries, i;

  1246.     AVStream *st;

  1247.     AVIStream *ast;

  1248.     unsigned int index, tag, flags, pos, len, first_packet = 1;

  1249.     unsigned last_pos= -1;

  1250.     unsigned last_idx= -1;

  1251.     int64_t idx1_pos, first_packet_pos = 0, data_offset = 0;

  1252.     int anykey = 0;

  1253. 

  1254.     nb_index_entries = size / 16;

  1255.     if (nb_index_entries <= 0)

  1256.         return -1;

  1257. 

  1258.     idx1_pos = avio_tell(pb);

  1259.     avio_seek(pb, avi->movi_list+4, SEEK_SET);

  1260.     if (avi_sync(s, 1) == 0) {

  1261.         first_packet_pos = avio_tell(pb) - 8;

  1262.     }

  1263.     avi->stream_index = -1;

  1264.     avio_seek(pb, idx1_pos, SEEK_SET);

  1265. 

  1266.     /* Read the entries and sort them in each stream component. */

  1267.     for(i = 0; i < nb_index_entries; i++) {

  1268.         if(url_feof(pb))

  1269.             return -1;

  1270. 

  1271.         tag = avio_rl32(pb);

  1272.         flags = avio_rl32(pb);

  1273.         pos = avio_rl32(pb);

  1274.         len = avio_rl32(pb);

  1275.         av_dlog(s, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",

  1276.                 i, tag, flags, pos, len);

  1277. 

  1278.         index = ((tag & 0xff) - '0') * 10;

  1279.         index += ((tag >> 8) & 0xff) - '0';

  1280.         if (index >= s->nb_streams)

  1281.             continue;

  1282.         st = s->streams[index];

  1283.         ast = st->priv_data;

  1284. 

  1285.         if(first_packet && first_packet_pos && len) {

  1286.             data_offset = first_packet_pos - pos;

  1287.             first_packet = 0;

  1288.         }

  1289.         pos += data_offset;

  1290. 

  1291.         av_dlog(s, "%d cum_len=%"PRId64"\n", len, ast->cum_len);

  1292. 

  1293. 

  1294.         // even if we have only a single stream, we should

  1295.         // switch to non-interleaved to get correct timestamps

  1296.         if(last_pos == pos)

  1297.             avi->non_interleaved= 1;

  1298.         if(last_idx != pos && len) {

  1299.             av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);

  1300.             last_idx= pos;

  1301.         }

  1302.         ast->cum_len += get_duration(ast, len);

  1303.         last_pos= pos;

  1304.         anykey |= flags&AVIIF_INDEX;

  1305.     }

  1306.     if (!anykey) {

  1307.         for (index = 0; index < s->nb_streams; index++) {

  1308.             st = s->streams[index];

  1309.             if (st->nb_index_entries)

  1310.                 st->index_entries[0].flags |= AVINDEX_KEYFRAME;

  1311.         }

  1312.     }

  1313.     return 0;

  1314. }

  1315. 

  1316. static int guess_ni_flag(AVFormatContext *s){

  1317.     int i;

  1318.     int64_t last_start=0;

  1319.     int64_t first_end= INT64_MAX;

  1320.     int64_t oldpos= avio_tell(s->pb);

  1321.     int *idx;

  1322.     int64_t min_pos, pos;

  1323. 

  1324.     for(i=0; i<s->nb_streams; i++){

  1325.         AVStream *st = s->streams[i];

  1326.         int n= st->nb_index_entries;

  1327.         unsigned int size;

  1328. 

  1329.         if(n <= 0)

  1330.             continue;

  1331. 

  1332.         if(n >= 2){

  1333.             int64_t pos= st->index_entries[0].pos;

  1334.             avio_seek(s->pb, pos + 4, SEEK_SET);

  1335.             size= avio_rl32(s->pb);

  1336.             if(pos + size > st->index_entries[1].pos)

  1337.                 last_start= INT64_MAX;

  1338.         }

  1339. 

  1340.         if(st->index_entries[0].pos > last_start)

  1341.             last_start= st->index_entries[0].pos;

  1342.         if(st->index_entries[n-1].pos < first_end)

  1343.             first_end= st->index_entries[n-1].pos;

  1344.     }

  1345.     avio_seek(s->pb, oldpos, SEEK_SET);

  1346.     if (last_start > first_end)

  1347.         return 1;

  1348.     idx= av_mallocz(sizeof(*idx) * s->nb_streams);

  1349.     for (min_pos=pos=0; min_pos!=INT64_MAX; pos= min_pos+1) {

  1350.         int64_t max_dts = INT64_MIN/2, min_dts= INT64_MAX/2;

  1351.         min_pos = INT64_MAX;

  1352. 

  1353.         for (i=0; i<s->nb_streams; i++) {

  1354.             AVStream *st = s->streams[i];

  1355.             int n= st->nb_index_entries;

  1356.             while (idx[i]<n && st->index_entries[idx[i]].pos < pos)

  1357.                 idx[i]++;

  1358.             if (idx[i] < n) {

  1359.                 min_dts = FFMIN(min_dts, av_rescale_q(st->index_entries[idx[i]].timestamp, st->time_base, AV_TIME_BASE_Q));

  1360.                 min_pos = FFMIN(min_pos, st->index_entries[idx[i]].pos);

  1361.             }

  1362.             if (idx[i])

  1363.                 max_dts = FFMAX(max_dts, av_rescale_q(st->index_entries[idx[i]-1].timestamp, st->time_base, AV_TIME_BASE_Q));

  1364.         }

  1365.         if(max_dts - min_dts > 2*AV_TIME_BASE) {

  1366.             av_free(idx);

  1367.             return 1;

  1368.         }

  1369.     }

  1370.     av_free(idx);

  1371.     return 0;

  1372. }

  1373. 

  1374. static int avi_load_index(AVFormatContext *s)

  1375. {

  1376.     AVIContext *avi = s->priv_data;

  1377.     AVIOContext *pb = s->pb;

  1378.     uint32_t tag, size;

  1379.     int64_t pos= avio_tell(pb);

  1380.     int64_t next;

  1381.     int ret = -1;

  1382. 

  1383.     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)

  1384.         goto the_end; // maybe truncated file

  1385.     av_dlog(s, "movi_end=0x%"PRIx64"\n", avi->movi_end);

  1386.     for(;;) {

  1387.         tag = avio_rl32(pb);

  1388.         size = avio_rl32(pb);

  1389.         if (url_feof(pb))

  1390.             break;

  1391.         next = avio_tell(pb) + size + (size & 1);

  1392. 

  1393.         av_dlog(s, "tag=%c%c%c%c size=0x%x\n",

  1394.                  tag        & 0xff,

  1395.                 (tag >>  8) & 0xff,

  1396.                 (tag >> 16) & 0xff,

  1397.                 (tag >> 24) & 0xff,

  1398.                 size);

  1399. 

  1400.         if (tag == MKTAG('i', 'd', 'x', '1') &&

  1401.             avi_read_idx1(s, size) >= 0) {

  1402.             avi->index_loaded=2;

  1403.             ret = 0;

  1404.         }else if(tag == MKTAG('L', 'I', 'S', 'T')) {

  1405.             uint32_t tag1 = avio_rl32(pb);

  1406. 

  1407.             if (tag1 == MKTAG('I', 'N', 'F', 'O'))

  1408.                 ff_read_riff_info(s, size - 4);

  1409.         }else if(!ret)

  1410.             break;

  1411. 

  1412.         if (avio_seek(pb, next, SEEK_SET) < 0)

  1413.             break; // something is wrong here

  1414.     }

  1415.  the_end:

  1416.     avio_seek(pb, pos, SEEK_SET);

  1417.     return ret;

  1418. }

  1419. 

  1420. static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)

  1421. {

  1422.     AVIStream *ast2 = st2->priv_data;

  1423.     int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);

  1424.     av_free_packet(&ast2->sub_pkt);

  1425.     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||

  1426.         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)

  1427.         ff_read_packet(ast2->sub_ctx, &ast2->sub_pkt);

  1428. }

  1429. 

  1430. static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

  1431. {

  1432.     AVIContext *avi = s->priv_data;

  1433.     AVStream *st;

  1434.     int i, index;

  1435.     int64_t pos, pos_min;

  1436.     AVIStream *ast;

  1437. 

  1438.     if (!avi->index_loaded) {

  1439.         /* we only load the index on demand */

  1440.         avi_load_index(s);

  1441.         avi->index_loaded |= 1;

  1442.     }

  1443.     av_assert0(stream_index>= 0);

  1444. 

  1445.     st = s->streams[stream_index];

  1446.     ast= st->priv_data;

  1447.     index= av_index_search_timestamp(st, timestamp * FFMAX(ast->sample_size, 1), flags);

  1448.     if (index<0) {

  1449.         if (st->nb_index_entries > 0)

  1450.             av_log(s, AV_LOG_DEBUG, "Failed to find timestamp %"PRId64 " in index %"PRId64 " .. %"PRId64 "\n",

  1451.                    timestamp * FFMAX(ast->sample_size, 1),

  1452.                    st->index_entries[0].timestamp,

  1453.                    st->index_entries[st->nb_index_entries - 1].timestamp);

  1454.         return -1;

  1455.     }

  1456. 

  1457.     /* find the position */

  1458.     pos = st->index_entries[index].pos;

  1459.     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);

  1460. 

  1461. //    av_log(s, AV_LOG_DEBUG, "XX %"PRId64" %d %"PRId64"\n", timestamp, index, st->index_entries[index].timestamp);

  1462. 

  1463.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1464.         /* One and only one real stream for DV in AVI, and it has video  */

  1465.         /* offsets. Calling with other stream indexes should have failed */

  1466.         /* the av_index_search_timestamp call above.                     */

  1467.         av_assert0(stream_index == 0);

  1468. 

  1469.         if(avio_seek(s->pb, pos, SEEK_SET) < 0)

  1470.             return -1;

  1471. 

  1472.         /* Feed the DV video stream version of the timestamp to the */

  1473.         /* DV demux so it can synthesize correct timestamps.        */

  1474.         ff_dv_offset_reset(avi->dv_demux, timestamp);

  1475. 

  1476.         avi->stream_index= -1;

  1477.         return 0;

  1478.     }

  1479. 

  1480.     pos_min= pos;

  1481.     for(i = 0; i < s->nb_streams; i++) {

  1482.         AVStream *st2 = s->streams[i];

  1483.         AVIStream *ast2 = st2->priv_data;

  1484. 

  1485.         ast2->packet_size=

  1486.         ast2->remaining= 0;

  1487. 

  1488.         if (ast2->sub_ctx) {

  1489.             seek_subtitle(st, st2, timestamp);

  1490.             continue;

  1491.         }

  1492. 

  1493.         if (st2->nb_index_entries <= 0)

  1494.             continue;

  1495. 

  1496. //        av_assert1(st2->codec->block_align);

  1497.         av_assert0((int64_t)st2->time_base.num*ast2->rate == (int64_t)st2->time_base.den*ast2->scale);

  1498.         index = av_index_search_timestamp(

  1499.                 st2,

  1500.                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),

  1501.                 flags | AVSEEK_FLAG_BACKWARD | (st2->codec->codec_type != AVMEDIA_TYPE_VIDEO ? AVSEEK_FLAG_ANY : 0));

  1502.         if(index<0)

  1503.             index=0;

  1504.         ast2->seek_pos= st2->index_entries[index].pos;

  1505.         pos_min= FFMIN(pos_min,ast2->seek_pos);

  1506.     }

  1507.     for(i = 0; i < s->nb_streams; i++) {

  1508.         AVStream *st2 = s->streams[i];

  1509.         AVIStream *ast2 = st2->priv_data;

  1510. 

  1511.         if (ast2->sub_ctx || st2->nb_index_entries <= 0)

  1512.             continue;

  1513. 

  1514.         index = av_index_search_timestamp(

  1515.                 st2,

  1516.                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),

  1517.                 flags | AVSEEK_FLAG_BACKWARD | (st2->codec->codec_type != AVMEDIA_TYPE_VIDEO ? AVSEEK_FLAG_ANY : 0));

  1518.         if(index<0)

  1519.             index=0;

  1520.         while(!avi->non_interleaved && index>0 && st2->index_entries[index-1].pos >= pos_min)

  1521.             index--;

  1522.         ast2->frame_offset = st2->index_entries[index].timestamp;

  1523.     }

  1524. 

  1525.     /* do the seek */

  1526.     if (avio_seek(s->pb, pos_min, SEEK_SET) < 0) {

  1527.         av_log(s, AV_LOG_ERROR, "Seek failed\n");

  1528.         return -1;

  1529.     }

  1530.     avi->stream_index= -1;

  1531.     avi->dts_max= INT_MIN;

  1532.     return 0;

  1533. }

  1534. 

  1535. static int avi_read_close(AVFormatContext *s)

  1536. {

  1537.     int i;

  1538.     AVIContext *avi = s->priv_data;

  1539. 

  1540.     for(i=0;i<s->nb_streams;i++) {

  1541.         AVStream *st = s->streams[i];

  1542.         AVIStream *ast = st->priv_data;

  1543.         if (ast) {

  1544.             if (ast->sub_ctx) {

  1545.                 av_freep(&ast->sub_ctx->pb);

  1546.                 avformat_close_input(&ast->sub_ctx);

  1547.             }

  1548.             av_free(ast->sub_buffer);

  1549.             av_free_packet(&ast->sub_pkt);

  1550.         }

  1551.     }

  1552. 

  1553.     av_free(avi->dv_demux);

  1554. 

  1555.     return 0;

  1556. }

  1557. 

  1558. static int avi_probe(AVProbeData *p)

  1559. {

  1560.     int i;

  1561. 

  1562.     /* check file header */

  1563.     for(i=0; avi_headers[i][0]; i++)

  1564.         if(!memcmp(p->buf  , avi_headers[i]  , 4) &&

  1565.            !memcmp(p->buf+8, avi_headers[i]+4, 4))

  1566.             return AVPROBE_SCORE_MAX;

  1567. 

  1568.     return 0;

  1569. }

  1570. 

  1571. AVInputFormat ff_avi_demuxer = {

  1572.     .name           = "avi",

  1573.     .long_name      = NULL_IF_CONFIG_SMALL("AVI (Audio Video Interleaved)"),

  1574.     .priv_data_size = sizeof(AVIContext),

  1575.     .read_probe     = avi_probe,

  1576.     .read_header    = avi_read_header,

  1577.     .read_packet    = avi_read_packet,

  1578.     .read_close     = avi_read_close,

  1579.     .read_seek      = avi_read_seek,

  1580.     .priv_class = &demuxer_class,

  1581. };