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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 Libav.

  6.  *

  7.  * Libav is free software; you can redistribute it and/or

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

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

  10.  * version 2.1 of the License, or (at your option) any later version.

  11.  *

  12.  * Libav is distributed in the hope that it will be useful,

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

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

  15.  * Lesser General Public License for more details.

  16.  *

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

  18.  * License along with Libav; if not, write to the Free Software

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

  20.  */

  21. 

  22. //#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. } AVIStream;

  58. 

  59. typedef struct {

  60.     int64_t  riff_end;

  61.     int64_t  movi_end;

  62.     int64_t  fsize;

  63.     int64_t movi_list;

  64.     int64_t last_pkt_pos;

  65.     int index_loaded;

  66.     int is_odml;

  67.     int non_interleaved;

  68.     int stream_index;

  69.     DVDemuxContext* dv_demux;

  70.     int odml_depth;

  71. #define MAX_ODML_DEPTH 1000

  72. } AVIContext;

  73. 

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

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

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

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

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

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

  80.     { 0 }

  81. };

  82. 

  83. static int avi_load_index(AVFormatContext *s);

  84. static int guess_ni_flag(AVFormatContext *s);

  85. 

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

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

  88.            str, tag & 0xff,                             \

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

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

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

  92.            size)

  93. 

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

  95.     if(ast->sample_size){

  96.         return len;

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

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

  99.     }else

  100.         return 1;

  101. }

  102. 

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

  104. {

  105.     AVIContext *avi = s->priv_data;

  106.     char header[8];

  107.     int i;

  108. 

  109.     /* check RIFF header */

  110.     avio_read(pb, header, 4);

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

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

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

  114. 

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

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

  117.             break;

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

  119.         return -1;

  120. 

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

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

  123. 

  124.     return 0;

  125. }

  126. 

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

  128.     AVIContext *avi = s->priv_data;

  129.     AVIOContext *pb = s->pb;

  130.     int longs_pre_entry= avio_rl16(pb);

  131.     int index_sub_type = avio_r8(pb);

  132.     int index_type     = avio_r8(pb);

  133.     int entries_in_use = avio_rl32(pb);

  134.     int chunk_id       = avio_rl32(pb);

  135.     int64_t base       = avio_rl64(pb);

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

  137.     AVStream *st;

  138.     AVIStream *ast;

  139.     int i;

  140.     int64_t last_pos= -1;

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

  142. 

  143. #ifdef DEBUG_SEEK

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

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

  146. #endif

  147. 

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

  149.         return -1;

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

  151.     ast = st->priv_data;

  152. 

  153.     if(index_sub_type)

  154.         return -1;

  155. 

  156.     avio_rl32(pb);

  157. 

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

  159.         return -1;

  160.     if(index_type>1)

  161.         return -1;

  162. 

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

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

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

  166.             base &= 0xFFFFFFFF;

  167.         else

  168.             return -1;

  169.     }

  170. 

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

  172.         if(index_type){

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

  174.             int len    = avio_rl32(pb);

  175.             int key= len >= 0;

  176.             len &= 0x7FFFFFFF;

  177. 

  178. #ifdef DEBUG_SEEK

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

  180. #endif

  181.             if(pb->eof_reached)

  182.                 return -1;

  183. 

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

  185.                 avi->non_interleaved= 1;

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

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

  188. 

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

  190.             last_pos= pos;

  191.         }else{

  192.             int64_t offset, pos;

  193.             int duration;

  194.             offset = avio_rl64(pb);

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

  196.             duration = avio_rl32(pb);

  197. 

  198.             if(pb->eof_reached)

  199.                 return -1;

  200. 

  201.             pos = avio_tell(pb);

  202. 

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

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

  205.                 return -1;

  206.             }

  207. 

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

  209.             avi->odml_depth++;

  210.             read_braindead_odml_indx(s, frame_num);

  211.             avi->odml_depth--;

  212.             frame_num += duration;

  213. 

  214.             avio_seek(pb, pos, SEEK_SET);

  215.         }

  216.     }

  217.     avi->index_loaded=1;

  218.     return 0;

  219. }

  220. 

  221. static void clean_index(AVFormatContext *s){

  222.     int i;

  223.     int64_t j;

  224. 

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

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

  227.         AVIStream *ast = st->priv_data;

  228.         int n= st->nb_index_entries;

  229.         int max= ast->sample_size;

  230.         int64_t pos, size, ts;

  231. 

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

  233.             continue;

  234. 

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

  236. 

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

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

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

  240. 

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

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

  243.         }

  244.     }

  245. }

  246. 

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

  248. {

  249.     AVIOContext *pb = s->pb;

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

  251. 

  252.     size += (size & 1);

  253. 

  254.     if (size == UINT_MAX)

  255.         return -1;

  256.     value = av_malloc(size+1);

  257.     if (!value)

  258.         return -1;

  259.     avio_read(pb, value, size);

  260.     value[size]=0;

  261. 

  262.     AV_WL32(key, tag);

  263. 

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

  265.                             AV_METADATA_DONT_STRDUP_VAL);

  266. }

  267. 

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

  269. {

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

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

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

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

  274.     }

  275. }

  276. 

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

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

  279. 

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

  281. {

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

  283.     int i, day, year;

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

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

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

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

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

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

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

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

  292.             }

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

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

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

  296.     }

  297. }

  298. 

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

  300. {

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

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

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

  304.         switch (tag) {

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

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

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

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

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

  310.                 const char *name = NULL;

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

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

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

  314.                 switch (tag) {

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

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

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

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

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

  320.                     break;

  321.                 }

  322.                 if (name)

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

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

  325.             }

  326.             break;

  327.         }

  328.         default:

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

  330.             break;

  331.         }

  332.     }

  333. }

  334. 

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

  336. {

  337.     AVIContext *avi = s->priv_data;

  338.     AVIOContext *pb = s->pb;

  339.     unsigned int tag, tag1, handler;

  340.     int codec_type, stream_index, frame_period, bit_rate;

  341.     unsigned int size;

  342.     int i;

  343.     AVStream *st;

  344.     AVIStream *ast = NULL;

  345.     int avih_width=0, avih_height=0;

  346.     int amv_file_format=0;

  347.     uint64_t list_end = 0;

  348.     int ret;

  349. 

  350.     avi->stream_index= -1;

  351. 

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

  353.         return -1;

  354. 

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

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

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

  358. 

  359.     /* first list tag */

  360.     stream_index = -1;

  361.     codec_type = -1;

  362.     frame_period = 0;

  363.     for(;;) {

  364.         if (pb->eof_reached)

  365.             goto fail;

  366.         tag = avio_rl32(pb);

  367.         size = avio_rl32(pb);

  368. 

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

  370. 

  371.         switch(tag) {

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

  373.             list_end = avio_tell(pb) + size;

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

  375.             tag1 = avio_rl32(pb);

  376. 

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

  378. 

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

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

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

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

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

  384.                 goto end_of_header;

  385.             }

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

  387.                 avi_read_info(s, list_end);

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

  389.                 avi_read_nikon(s, list_end);

  390. 

  391.             break;

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

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

  394.             size += (size & 1);

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

  396.             avio_skip(pb, size);

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

  398.             break;

  399.         }

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

  401.             avi->is_odml = 1;

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

  403.             break;

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

  405.             amv_file_format=1;

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

  407.             /* AVI header */

  408.             /* using frame_period is bad idea */

  409.             frame_period = avio_rl32(pb);

  410.             bit_rate = avio_rl32(pb) * 8;

  411.             avio_rl32(pb);

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

  413. 

  414.             avio_skip(pb, 2 * 4);

  415.             avio_rl32(pb);

  416.             avio_rl32(pb);

  417.             avih_width=avio_rl32(pb);

  418.             avih_height=avio_rl32(pb);

  419. 

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

  421.             break;

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

  423.             /* stream header */

  424. 

  425.             tag1 = avio_rl32(pb);

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

  427. 

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

  429.                 avio_skip(pb, size - 8);

  430.                 break;

  431.             }else{

  432.                 stream_index++;

  433.                 st = av_new_stream(s, stream_index);

  434.                 if (!st)

  435.                     goto fail;

  436. 

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

  438.                 if (!ast)

  439.                     goto fail;

  440.                 st->priv_data = ast;

  441.             }

  442.             if(amv_file_format)

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

  444. 

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

  446. 

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

  448.                 int64_t dv_dur;

  449. 

  450.                 /*

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

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

  453.                  */

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

  455.                     goto fail;

  456. 

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

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

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

  460.                    goto fail;

  461. 

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

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

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

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

  466.                 s->nb_streams = 0;

  467.                 if (CONFIG_DV_DEMUXER) {

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

  469.                     if (!avi->dv_demux)

  470.                         goto fail;

  471.                 }

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

  473.                 avio_skip(pb, 3 * 4);

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

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

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

  477. 

  478.                 dv_dur = avio_rl32(pb);

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

  480.                     dv_dur *= AV_TIME_BASE;

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

  482.                 }

  483.                 /*

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

  485.                  *      will make a guess based on bitrate.

  486.                  */

  487. 

  488.                 stream_index = s->nb_streams - 1;

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

  490.                 break;

  491.             }

  492. 

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

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

  495. 

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

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

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

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

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

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

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

  503.                 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);

  504.                 if(frame_period){

  505.                     ast->rate = 1000000;

  506.                     ast->scale = frame_period;

  507.                 }else{

  508.                     ast->rate = 25;

  509.                     ast->scale = 1;

  510.                 }

  511.             }

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

  513. 

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

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

  516. 

  517.             st->start_time = 0;

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

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

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

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

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

  523. 

  524.             switch(tag1) {

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

  526.                 codec_type = AVMEDIA_TYPE_VIDEO;

  527. 

  528.                 ast->sample_size = 0;

  529.                 break;

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

  531.                 codec_type = AVMEDIA_TYPE_AUDIO;

  532.                 break;

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

  534.                 codec_type = AVMEDIA_TYPE_SUBTITLE;

  535.                 break;

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

  537.                 codec_type = AVMEDIA_TYPE_DATA;

  538.                 break;

  539.             default:

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

  541.                 goto fail;

  542.             }

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

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

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

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

  547.             break;

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

  549.             /* stream header */

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

  551.                 avio_skip(pb, size);

  552.             } else {

  553.                 uint64_t cur_pos = avio_tell(pb);

  554.                 if (cur_pos < list_end)

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

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

  557.                 switch(codec_type) {

  558.                 case AVMEDIA_TYPE_VIDEO:

  559.                     if(amv_file_format){

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

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

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

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

  564.                         avio_skip(pb, size);

  565.                         break;

  566.                     }

  567.                     tag1 = ff_get_bmp_header(pb, st);

  568. 

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

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

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

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

  573.                         break;

  574.                     }

  575. 

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

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

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

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

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

  581.                             return AVERROR(ENOMEM);

  582.                         }

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

  584.                     }

  585. 

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

  587.                         avio_r8(pb);

  588. 

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

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

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

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

  593.                         st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));

  594. #if HAVE_BIGENDIAN

  595.                         for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)

  596.                             st->codec->palctrl->palette[i] = av_bswap32(((uint32_t*)st->codec->extradata)[i]);

  597. #else

  598.                         memcpy(st->codec->palctrl->palette, st->codec->extradata,

  599.                                FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));

  600. #endif

  601.                         st->codec->palctrl->palette_changed = 1;

  602.                     }

  603. 

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

  605. 

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

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

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

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

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

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

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

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

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

  615. 

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

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

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

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

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

  621.                     }

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

  623. 

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

  625.                     break;

  626.                 case AVMEDIA_TYPE_AUDIO:

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

  628.                     if (ret < 0)

  629.                         return ret;

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

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

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

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

  634.                     }

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

  636.                         avio_skip(pb, 1);

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

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

  639.                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;

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

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

  642.                      * fail. */

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

  644.                         st->need_parsing = AVSTREAM_PARSE_NONE;

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

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

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

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

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

  650.                     }

  651.                     if (amv_file_format){

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

  653.                         ast->dshow_block_align = 0;

  654.                     }

  655.                     break;

  656.                 case AVMEDIA_TYPE_SUBTITLE:

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

  658.                     st->codec->codec_id   = CODEC_ID_PROBE;

  659.                     break;

  660.                 default:

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

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

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

  664.                     avio_skip(pb, size);

  665.                     break;

  666.                 }

  667.             }

  668.             break;

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

  670.             i= avio_tell(pb);

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

  672.                 read_braindead_odml_indx(s, 0);

  673.             }

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

  675.             break;

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

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

  678.                 AVRational active, active_aspect;

  679. 

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

  681.                 avio_rl32(pb);

  682.                 avio_rl32(pb);

  683.                 avio_rl32(pb);

  684.                 avio_rl32(pb);

  685.                 avio_rl32(pb);

  686. 

  687.                 active_aspect.den= avio_rl16(pb);

  688.                 active_aspect.num= avio_rl16(pb);

  689.                 active.num       = avio_rl32(pb);

  690.                 active.den       = avio_rl32(pb);

  691.                 avio_rl32(pb); //nbFieldsPerFrame

  692. 

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

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

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

  696.                 }

  697.                 size -= 9*4;

  698.             }

  699.             avio_skip(pb, size);

  700.             break;

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

  702.             if(s->nb_streams){

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

  704.                 break;

  705.             }

  706.         default:

  707.             if(size > 1000000){

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

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

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

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

  712.                 goto end_of_header;

  713.             }

  714.             /* skip tag */

  715.             size += (size & 1);

  716.             avio_skip(pb, size);

  717.             break;

  718.         }

  719.     }

  720.  end_of_header:

  721.     /* check stream number */

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

  723.     fail:

  724.         return -1;

  725.     }

  726. 

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

  728.         avi_load_index(s);

  729.     avi->index_loaded = 1;

  730.     avi->non_interleaved |= guess_ni_flag(s);

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

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

  733.         if(st->nb_index_entries)

  734.             break;

  735.     }

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

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

  738.         avi->non_interleaved=0;

  739.     }

  740. 

  741.     if(avi->non_interleaved) {

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

  743.         clean_index(s);

  744.     }

  745. 

  746.     ff_metadata_conv_ctx(s, NULL, ff_avi_metadata_conv);

  747. 

  748.     return 0;

  749. }

  750. 

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

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

  753.         uint8_t desc[256];

  754.         int score = AVPROBE_SCORE_MAX / 2, ret;

  755.         AVIStream *ast = st->priv_data;

  756.         AVInputFormat *sub_demuxer;

  757.         AVRational time_base;

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

  759.                                               pkt->size - 7,

  760.                                               0, NULL, NULL, NULL, NULL);

  761.         AVProbeData pd;

  762.         unsigned int desc_len = avio_rl32(pb);

  763. 

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

  765.             goto error;

  766. 

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

  768.         avio_skip(pb, desc_len - ret);

  769.         if (*desc)

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

  771. 

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

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

  774. 

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

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

  777.             goto error;

  778. 

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

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

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

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

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

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

  785.         }

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

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

  788.         return 1;

  789. error:

  790.         av_freep(&pb);

  791.     }

  792.     return 0;

  793. }

  794. 

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

  796.                                   AVPacket *pkt)

  797. {

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

  799.     int64_t ts, next_ts, ts_min = INT64_MAX;

  800.     AVStream *st, *sub_st = NULL;

  801.     int i;

  802. 

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

  804.                            AV_TIME_BASE_Q);

  805. 

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

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

  808.         ast = st->priv_data;

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

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

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

  812.                 ts_min = ts;

  813.                 sub_st = st;

  814.             }

  815.         }

  816.     }

  817. 

  818.     if (sub_st) {

  819.         ast = sub_st->priv_data;

  820.         *pkt = ast->sub_pkt;

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

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

  823.             ast->sub_pkt.data = NULL;

  824.     }

  825.     return sub_st;

  826. }

  827. 

  828. static int get_stream_idx(int *d){

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

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

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

  832.     }else{

  833.         return 100; //invalid stream ID

  834.     }

  835. }

  836. 

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

  838. {

  839.     AVIContext *avi = s->priv_data;

  840.     AVIOContext *pb = s->pb;

  841.     int n, d[8];

  842.     unsigned int size;

  843.     int64_t i, sync;

  844.     void* dstr;

  845. 

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

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

  848.         if (size >= 0)

  849.             return size;

  850.     }

  851. 

  852.     if(avi->non_interleaved){

  853.         int best_stream_index = 0;

  854.         AVStream *best_st= NULL;

  855.         AVIStream *best_ast;

  856.         int64_t best_ts= INT64_MAX;

  857.         int i;

  858. 

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

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

  861.             AVIStream *ast = st->priv_data;

  862.             int64_t ts= ast->frame_offset;

  863.             int64_t last_ts;

  864. 

  865.             if(!st->nb_index_entries)

  866.                 continue;

  867. 

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

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

  870.                 continue;

  871. 

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

  873. 

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

  875.             if(ts < best_ts){

  876.                 best_ts= ts;

  877.                 best_st= st;

  878.                 best_stream_index= i;

  879.             }

  880.         }

  881.         if(!best_st)

  882.             return -1;

  883. 

  884.         best_ast = best_st->priv_data;

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

  886.         if(best_ast->remaining)

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

  888.         else{

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

  890.             if(i>=0)

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

  892.         }

  893. 

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

  895.         if(i>=0){

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

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

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

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

  900. 

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

  902. 

  903.             avi->stream_index= best_stream_index;

  904.             if(!best_ast->remaining)

  905.                 best_ast->packet_size=

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

  907.         }

  908.     }

  909. 

  910. resync:

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

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

  913.         AVIStream *ast= st->priv_data;

  914.         int size, err;

  915. 

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

  917.             return 0;

  918. 

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

  920.             size= INT_MAX;

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

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

  923.             size= 1024*ast->sample_size;

  924.         else

  925.             size= ast->sample_size;

  926. 

  927.         if(size > ast->remaining)

  928.             size= ast->remaining;

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

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

  931.         if(err<0)

  932.             return err;

  933. 

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

  935.             void *ptr= av_realloc(pkt->data, pkt->size + 4*256 + FF_INPUT_BUFFER_PADDING_SIZE);

  936.             if(ptr){

  937.             ast->has_pal=0;

  938.             pkt->size += 4*256;

  939.             pkt->data= ptr;

  940.                 memcpy(pkt->data + pkt->size - 4*256, ast->pal, 4*256);

  941.             }else

  942.                 av_log(s, AV_LOG_ERROR, "Failed to append palette\n");

  943.         }

  944. 

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

  946.             dstr = pkt->destruct;

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

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

  949.             pkt->destruct = dstr;

  950.             pkt->flags |= AV_PKT_FLAG_KEY;

  951.             if (size < 0)

  952.                 av_free_packet(pkt);

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

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

  955.             ast->frame_offset++;

  956.             avi->stream_index = -1;

  957.             ast->remaining = 0;

  958.             goto resync;

  959.         } else {

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

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

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

  963.             if(ast->sample_size)

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

  965. //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);

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

  967. 

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

  969.                 AVIndexEntry *e;

  970.                 int index;

  971.                 assert(st->index_entries);

  972. 

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

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

  975. 

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

  977.                     if (e->flags & AVINDEX_KEYFRAME)

  978.                         pkt->flags |= AV_PKT_FLAG_KEY;

  979.                 }

  980.             } else {

  981.                 pkt->flags |= AV_PKT_FLAG_KEY;

  982.             }

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

  984.         }

  985.         ast->remaining -= size;

  986.         if(!ast->remaining){

  987.             avi->stream_index= -1;

  988.             ast->packet_size= 0;

  989.         }

  990. 

  991.         return size;

  992.     }

  993. 

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

  995.     for(i=sync=avio_tell(pb); !pb->eof_reached; i++) {

  996.         int j;

  997. 

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

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

  1000.         d[7]= avio_r8(pb);

  1001. 

  1002.         size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);

  1003. 

  1004.         n= get_stream_idx(d+2);

  1005. //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);

  1006.         if(i + (uint64_t)size > avi->fsize || d[0]<0)

  1007.             continue;

  1008. 

  1009.         //parse ix##

  1010.         if(  (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)

  1011.         //parse JUNK

  1012.            ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')

  1013.            ||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){

  1014.             avio_skip(pb, size);

  1015. //av_log(s, AV_LOG_DEBUG, "SKIP\n");

  1016.             goto resync;

  1017.         }

  1018. 

  1019.         //parse stray LIST

  1020.         if(d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T'){

  1021.             avio_skip(pb, 4);

  1022.             goto resync;

  1023.         }

  1024. 

  1025.         n= get_stream_idx(d);

  1026. 

  1027.         if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)

  1028.             continue;

  1029. 

  1030.         //detect ##ix chunk and skip

  1031.         if(d[2] == 'i' && d[3] == 'x' && n < s->nb_streams){

  1032.             avio_skip(pb, size);

  1033.             goto resync;

  1034.         }

  1035. 

  1036.         //parse ##dc/##wb

  1037.         if(n < s->nb_streams){

  1038.             AVStream *st;

  1039.             AVIStream *ast;

  1040.             st = s->streams[n];

  1041.             ast = st->priv_data;

  1042. 

  1043.             if(s->nb_streams>=2){

  1044.                 AVStream *st1  = s->streams[1];

  1045.                 AVIStream *ast1= st1->priv_data;

  1046.                 //workaround for broken small-file-bug402.avi

  1047.                 if(   d[2] == 'w' && d[3] == 'b'

  1048.                    && n==0

  1049.                    && st ->codec->codec_type == AVMEDIA_TYPE_VIDEO

  1050.                    && st1->codec->codec_type == AVMEDIA_TYPE_AUDIO

  1051.                    && ast->prefix == 'd'*256+'c'

  1052.                    && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)

  1053.                   ){

  1054.                     n=1;

  1055.                     st = st1;

  1056.                     ast = ast1;

  1057.                     av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");

  1058.                 }

  1059.             }

  1060. 

  1061. 

  1062.             if(   (st->discard >= AVDISCARD_DEFAULT && size==0)

  1063.                /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & AV_PKT_FLAG_KEY))*/ //FIXME needs a little reordering

  1064.                || st->discard >= AVDISCARD_ALL){

  1065.                 ast->frame_offset += get_duration(ast, size);

  1066.                 avio_skip(pb, size);

  1067.                 goto resync;

  1068.             }

  1069. 

  1070.             if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {

  1071.                 int k = avio_r8(pb);

  1072.                 int last = (k + avio_r8(pb) - 1) & 0xFF;

  1073. 

  1074.                 avio_rl16(pb); //flags

  1075. 

  1076.                 for (; k <= last; k++)

  1077.                     ast->pal[k] = avio_rb32(pb)>>8;// b + (g << 8) + (r << 16);

  1078.                 ast->has_pal= 1;

  1079.                 goto resync;

  1080.             } else if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||

  1081.                          d[2]*256+d[3] == ast->prefix /*||

  1082.                          (d[2] == 'd' && d[3] == 'c') ||

  1083.                          (d[2] == 'w' && d[3] == 'b')*/) {

  1084. 

  1085. //av_log(s, AV_LOG_DEBUG, "OK\n");

  1086.                 if(d[2]*256+d[3] == ast->prefix)

  1087.                     ast->prefix_count++;

  1088.                 else{

  1089.                     ast->prefix= d[2]*256+d[3];

  1090.                     ast->prefix_count= 0;

  1091.                 }

  1092. 

  1093.                 avi->stream_index= n;

  1094.                 ast->packet_size= size + 8;

  1095.                 ast->remaining= size;

  1096. 

  1097.                 if(size || !ast->sample_size){

  1098.                     uint64_t pos= avio_tell(pb) - 8;

  1099.                     if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){

  1100.                         av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);

  1101.                     }

  1102.                 }

  1103.                 goto resync;

  1104.             }

  1105.         }

  1106.     }

  1107. 

  1108.     return AVERROR_EOF;

  1109. }

  1110. 

  1111. /* XXX: We make the implicit supposition that the positions are sorted

  1112.    for each stream. */

  1113. static int avi_read_idx1(AVFormatContext *s, int size)

  1114. {

  1115.     AVIContext *avi = s->priv_data;

  1116.     AVIOContext *pb = s->pb;

  1117.     int nb_index_entries, i;

  1118.     AVStream *st;

  1119.     AVIStream *ast;

  1120.     unsigned int index, tag, flags, pos, len;

  1121.     unsigned last_pos= -1;

  1122. 

  1123.     nb_index_entries = size / 16;

  1124.     if (nb_index_entries <= 0)

  1125.         return -1;

  1126. 

  1127.     /* Read the entries and sort them in each stream component. */

  1128.     for(i = 0; i < nb_index_entries; i++) {

  1129.         tag = avio_rl32(pb);

  1130.         flags = avio_rl32(pb);

  1131.         pos = avio_rl32(pb);

  1132.         len = avio_rl32(pb);

  1133. #if defined(DEBUG_SEEK)

  1134.         av_log(s, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",

  1135.                i, tag, flags, pos, len);

  1136. #endif

  1137.         if(i==0 && pos > avi->movi_list)

  1138.             avi->movi_list= 0; //FIXME better check

  1139.         pos += avi->movi_list;

  1140. 

  1141.         index = ((tag & 0xff) - '0') * 10;

  1142.         index += ((tag >> 8) & 0xff) - '0';

  1143.         if (index >= s->nb_streams)

  1144.             continue;

  1145.         st = s->streams[index];

  1146.         ast = st->priv_data;

  1147. 

  1148. #if defined(DEBUG_SEEK)

  1149.         av_log(s, AV_LOG_DEBUG, "%d cum_len=%"PRId64"\n", len, ast->cum_len);

  1150. #endif

  1151.         if(pb->eof_reached)

  1152.             return -1;

  1153. 

  1154.         if(last_pos == pos)

  1155.             avi->non_interleaved= 1;

  1156.         else if(len || !ast->sample_size)

  1157.             av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);

  1158.         ast->cum_len += get_duration(ast, len);

  1159.         last_pos= pos;

  1160.     }

  1161.     return 0;

  1162. }

  1163. 

  1164. static int guess_ni_flag(AVFormatContext *s){

  1165.     int i;

  1166.     int64_t last_start=0;

  1167.     int64_t first_end= INT64_MAX;

  1168.     int64_t oldpos= avio_tell(s->pb);

  1169. 

  1170.     for(i=0; i<s->nb_streams; i++){

  1171.         AVStream *st = s->streams[i];

  1172.         int n= st->nb_index_entries;

  1173.         unsigned int size;

  1174. 

  1175.         if(n <= 0)

  1176.             continue;

  1177. 

  1178.         if(n >= 2){

  1179.             int64_t pos= st->index_entries[0].pos;

  1180.             avio_seek(s->pb, pos + 4, SEEK_SET);

  1181.             size= avio_rl32(s->pb);

  1182.             if(pos + size > st->index_entries[1].pos)

  1183.                 last_start= INT64_MAX;

  1184.         }

  1185. 

  1186.         if(st->index_entries[0].pos > last_start)

  1187.             last_start= st->index_entries[0].pos;

  1188.         if(st->index_entries[n-1].pos < first_end)

  1189.             first_end= st->index_entries[n-1].pos;

  1190.     }

  1191.     avio_seek(s->pb, oldpos, SEEK_SET);

  1192.     return last_start > first_end;

  1193. }

  1194. 

  1195. static int avi_load_index(AVFormatContext *s)

  1196. {

  1197.     AVIContext *avi = s->priv_data;

  1198.     AVIOContext *pb = s->pb;

  1199.     uint32_t tag, size;

  1200.     int64_t pos= avio_tell(pb);

  1201.     int ret = -1;

  1202. 

  1203.     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)

  1204.         goto the_end; // maybe truncated file

  1205. #ifdef DEBUG_SEEK

  1206.     printf("movi_end=0x%"PRIx64"\n", avi->movi_end);

  1207. #endif

  1208.     for(;;) {

  1209.         if (pb->eof_reached)

  1210.             break;

  1211.         tag = avio_rl32(pb);

  1212.         size = avio_rl32(pb);

  1213. #ifdef DEBUG_SEEK

  1214.         printf("tag=%c%c%c%c size=0x%x\n",

  1215.                tag & 0xff,

  1216.                (tag >> 8) & 0xff,

  1217.                (tag >> 16) & 0xff,

  1218.                (tag >> 24) & 0xff,

  1219.                size);

  1220. #endif

  1221.         switch(tag) {

  1222.         case MKTAG('i', 'd', 'x', '1'):

  1223.             if (avi_read_idx1(s, size) < 0)

  1224.                 goto skip;

  1225.             ret = 0;

  1226.                 goto the_end;

  1227.             break;

  1228.         default:

  1229.         skip:

  1230.             size += (size & 1);

  1231.             if (avio_skip(pb, size) < 0)

  1232.                 goto the_end; // something is wrong here

  1233.             break;

  1234.         }

  1235.     }

  1236.  the_end:

  1237.     avio_seek(pb, pos, SEEK_SET);

  1238.     return ret;

  1239. }

  1240. 

  1241. static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)

  1242. {

  1243.     AVIStream *ast2 = st2->priv_data;

  1244.     int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);

  1245.     av_free_packet(&ast2->sub_pkt);

  1246.     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||

  1247.         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)

  1248.         av_read_packet(ast2->sub_ctx, &ast2->sub_pkt);

  1249. }

  1250. 

  1251. static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

  1252. {

  1253.     AVIContext *avi = s->priv_data;

  1254.     AVStream *st;

  1255.     int i, index;

  1256.     int64_t pos;

  1257.     AVIStream *ast;

  1258. 

  1259.     if (!avi->index_loaded) {

  1260.         /* we only load the index on demand */

  1261.         avi_load_index(s);

  1262.         avi->index_loaded = 1;

  1263.     }

  1264.     assert(stream_index>= 0);

  1265. 

  1266.     st = s->streams[stream_index];

  1267.     ast= st->priv_data;

  1268.     index= av_index_search_timestamp(st, timestamp * FFMAX(ast->sample_size, 1), flags);

  1269.     if(index<0)

  1270.         return -1;

  1271. 

  1272.     /* find the position */

  1273.     pos = st->index_entries[index].pos;

  1274.     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);

  1275. 

  1276. //    av_log(s, AV_LOG_DEBUG, "XX %"PRId64" %d %"PRId64"\n", timestamp, index, st->index_entries[index].timestamp);

  1277. 

  1278.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1279.         /* One and only one real stream for DV in AVI, and it has video  */

  1280.         /* offsets. Calling with other stream indexes should have failed */

  1281.         /* the av_index_search_timestamp call above.                     */

  1282.         assert(stream_index == 0);

  1283. 

  1284.         /* Feed the DV video stream version of the timestamp to the */

  1285.         /* DV demux so it can synthesize correct timestamps.        */

  1286.         dv_offset_reset(avi->dv_demux, timestamp);

  1287. 

  1288.         avio_seek(s->pb, pos, SEEK_SET);

  1289.         avi->stream_index= -1;

  1290.         return 0;

  1291.     }

  1292. 

  1293.     for(i = 0; i < s->nb_streams; i++) {

  1294.         AVStream *st2 = s->streams[i];

  1295.         AVIStream *ast2 = st2->priv_data;

  1296. 

  1297.         ast2->packet_size=

  1298.         ast2->remaining= 0;

  1299. 

  1300.         if (ast2->sub_ctx) {

  1301.             seek_subtitle(st, st2, timestamp);

  1302.             continue;

  1303.         }

  1304. 

  1305.         if (st2->nb_index_entries <= 0)

  1306.             continue;

  1307. 

  1308. //        assert(st2->codec->block_align);

  1309.         assert((int64_t)st2->time_base.num*ast2->rate == (int64_t)st2->time_base.den*ast2->scale);

  1310.         index = av_index_search_timestamp(

  1311.                 st2,

  1312.                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),

  1313.                 flags | AVSEEK_FLAG_BACKWARD);

  1314.         if(index<0)

  1315.             index=0;

  1316. 

  1317.         if(!avi->non_interleaved){

  1318.             while(index>0 && st2->index_entries[index].pos > pos)

  1319.                 index--;

  1320.             while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)

  1321.                 index++;

  1322.         }

  1323. 

  1324. //        av_log(s, AV_LOG_DEBUG, "%"PRId64" %d %"PRId64"\n", timestamp, index, st2->index_entries[index].timestamp);

  1325.         /* extract the current frame number */

  1326.         ast2->frame_offset = st2->index_entries[index].timestamp;

  1327.     }

  1328. 

  1329.     /* do the seek */

  1330.     avio_seek(s->pb, pos, SEEK_SET);

  1331.     avi->stream_index= -1;

  1332.     return 0;

  1333. }

  1334. 

  1335. static int avi_read_close(AVFormatContext *s)

  1336. {

  1337.     int i;

  1338.     AVIContext *avi = s->priv_data;

  1339. 

  1340.     for(i=0;i<s->nb_streams;i++) {

  1341.         AVStream *st = s->streams[i];

  1342.         AVIStream *ast = st->priv_data;

  1343.         av_free(st->codec->palctrl);

  1344.         if (ast) {

  1345.             if (ast->sub_ctx) {

  1346.                 av_freep(&ast->sub_ctx->pb);

  1347.                 av_close_input_stream(ast->sub_ctx);

  1348.             }

  1349.             av_free(ast->sub_buffer);

  1350.             av_free_packet(&ast->sub_pkt);

  1351.         }

  1352.     }

  1353. 

  1354.     av_free(avi->dv_demux);

  1355. 

  1356.     return 0;

  1357. }

  1358. 

  1359. static int avi_probe(AVProbeData *p)

  1360. {

  1361.     int i;

  1362. 

  1363.     /* check file header */

  1364.     for(i=0; avi_headers[i][0]; i++)

  1365.         if(!memcmp(p->buf  , avi_headers[i]  , 4) &&

  1366.            !memcmp(p->buf+8, avi_headers[i]+4, 4))

  1367.             return AVPROBE_SCORE_MAX;

  1368. 

  1369.     return 0;

  1370. }

  1371. 

  1372. AVInputFormat ff_avi_demuxer = {

  1373.     "avi",

  1374.     NULL_IF_CONFIG_SMALL("AVI format"),

  1375.     sizeof(AVIContext),

  1376.     avi_probe,

  1377.     avi_read_header,

  1378.     avi_read_packet,

  1379.     avi_read_close,

  1380.     avi_read_seek,

  1381. };