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FFmpeg/libavformat/avidec.c

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  1. /*

  2.  * AVI demuxer

  3.  * Copyright (c) 2001 Fabrice Bellard

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

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

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

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

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

  11.  *

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

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

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

  15.  * Lesser General Public License for more details.

  16.  *

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

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

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

  20.  */

  21. 

  22. //#define DEBUG

  23. //#define DEBUG_SEEK

  24. 

  25. #include <strings.h>

  26. #include "libavutil/intreadwrite.h"

  27. #include "libavutil/bswap.h"

  28. #include "libavutil/opt.h"

  29. #include "libavutil/dict.h"

  30. #include "avformat.h"

  31. #include "avi.h"

  32. #include "dv.h"

  33. #include "riff.h"

  34. 

  35. #undef NDEBUG

  36. #include <assert.h>

  37. 

  38. typedef struct AVIStream {

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

  40.                          (used to compute the pts) */

  41.     int remaining;

  42.     int packet_size;

  43. 

  44.     int scale;

  45.     int rate;

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

  47. 

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

  49. 

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

  51.     int prefix_count;

  52.     uint32_t pal[256];

  53.     int has_pal;

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

  55. 

  56.     AVFormatContext *sub_ctx;

  57.     AVPacket sub_pkt;

  58.     uint8_t *sub_buffer;

  59. 

  60.     int64_t seek_pos;

  61. } AVIStream;

  62. 

  63. typedef struct {

  64.     const AVClass *class;

  65.     int64_t  riff_end;

  66.     int64_t  movi_end;

  67.     int64_t  fsize;

  68.     int64_t movi_list;

  69.     int64_t last_pkt_pos;

  70.     int index_loaded;

  71.     int is_odml;

  72.     int non_interleaved;

  73.     int stream_index;

  74.     DVDemuxContext* dv_demux;

  75.     int odml_depth;

  76.     int use_odml;

  77. #define MAX_ODML_DEPTH 1000

  78. } AVIContext;

  79. 

  80. 

  81. static const AVOption options[] = {

  82.     { "use_odml", "use odml index", offsetof(AVIContext, use_odml), FF_OPT_TYPE_INT, 1, -1, 1, AV_OPT_FLAG_DECODING_PARAM},

  83.     { NULL },

  84. };

  85. 

  86. static const AVClass demuxer_class = {

  87.     "AVI demuxer",

  88.     av_default_item_name,

  89.     options,

  90.     LIBAVUTIL_VERSION_INT,

  91. };

  92. 

  93. 

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

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

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

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

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

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

  100.     { 0 }

  101. };

  102. 

  103. static int avi_load_index(AVFormatContext *s);

  104. static int guess_ni_flag(AVFormatContext *s);

  105. 

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

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

  108.            str, tag & 0xff,                             \

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

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

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

  112.            size)

  113. 

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

  115.     if(ast->sample_size){

  116.         return len;

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

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

  119.     }else

  120.         return 1;

  121. }

  122. 

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

  124. {

  125.     AVIContext *avi = s->priv_data;

  126.     char header[8];

  127.     int i;

  128. 

  129.     /* check RIFF header */

  130.     avio_read(pb, header, 4);

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

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

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

  134. 

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

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

  137.             break;

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

  139.         return -1;

  140. 

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

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

  143. 

  144.     return 0;

  145. }

  146. 

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

  148.     AVIContext *avi = s->priv_data;

  149.     AVIOContext *pb = s->pb;

  150.     int longs_pre_entry= avio_rl16(pb);

  151.     int index_sub_type = avio_r8(pb);

  152.     int index_type     = avio_r8(pb);

  153.     int entries_in_use = avio_rl32(pb);

  154.     int chunk_id       = avio_rl32(pb);

  155.     int64_t base       = avio_rl64(pb);

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

  157.     AVStream *st;

  158.     AVIStream *ast;

  159.     int i;

  160.     int64_t last_pos= -1;

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

  162. 

  163. #ifdef DEBUG_SEEK

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

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

  166. #endif

  167. 

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

  169.         return -1;

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

  171.     ast = st->priv_data;

  172. 

  173.     if(index_sub_type)

  174.         return -1;

  175. 

  176.     avio_rl32(pb);

  177. 

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

  179.         return -1;

  180.     if(index_type>1)

  181.         return -1;

  182. 

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

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

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

  186.             base &= 0xFFFFFFFF;

  187.         else

  188.             return -1;

  189.     }

  190. 

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

  192.         if(index_type){

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

  194.             int len    = avio_rl32(pb);

  195.             int key= len >= 0;

  196.             len &= 0x7FFFFFFF;

  197. 

  198. #ifdef DEBUG_SEEK

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

  200. #endif

  201.             if(url_feof(pb))

  202.                 return -1;

  203. 

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

  205.                 avi->non_interleaved= 1;

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

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

  208. 

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

  210.             last_pos= pos;

  211.         }else{

  212.             int64_t offset, pos;

  213.             int duration;

  214.             offset = avio_rl64(pb);

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

  216.             duration = avio_rl32(pb);

  217. 

  218.             if(url_feof(pb))

  219.                 return -1;

  220. 

  221.             pos = avio_tell(pb);

  222. 

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

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

  225.                 return -1;

  226.             }

  227. 

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

  229.             avi->odml_depth++;

  230.             read_braindead_odml_indx(s, frame_num);

  231.             avi->odml_depth--;

  232.             frame_num += duration;

  233. 

  234.             avio_seek(pb, pos, SEEK_SET);

  235.         }

  236.     }

  237.     avi->index_loaded=1;

  238.     return 0;

  239. }

  240. 

  241. static void clean_index(AVFormatContext *s){

  242.     int i;

  243.     int64_t j;

  244. 

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

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

  247.         AVIStream *ast = st->priv_data;

  248.         int n= st->nb_index_entries;

  249.         int max= ast->sample_size;

  250.         int64_t pos, size, ts;

  251. 

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

  253.             continue;

  254. 

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

  256. 

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

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

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

  260. 

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

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

  263.         }

  264.     }

  265. }

  266. 

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

  268. {

  269.     AVIOContext *pb = s->pb;

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

  271. 

  272.     size += (size & 1);

  273. 

  274.     if (size == UINT_MAX)

  275.         return -1;

  276.     value = av_malloc(size+1);

  277.     if (!value)

  278.         return -1;

  279.     avio_read(pb, value, size);

  280.     value[size]=0;

  281. 

  282.     AV_WL32(key, tag);

  283. 

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

  285.                             AV_DICT_DONT_STRDUP_VAL);

  286. }

  287. 

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

  289. {

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

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

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

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

  294.     }

  295. }

  296. 

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

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

  299. 

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

  301. {

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

  303.     int i, day, year;

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

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

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

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

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

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

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

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

  312.             }

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

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

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

  316.     }

  317. }

  318. 

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

  320. {

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

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

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

  324.         switch (tag) {

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

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

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

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

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

  330.                 const char *name = NULL;

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

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

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

  334.                 switch (tag) {

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

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

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

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

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

  340.                     break;

  341.                 }

  342.                 if (name)

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

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

  345.             }

  346.             break;

  347.         }

  348.         default:

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

  350.             break;

  351.         }

  352.     }

  353. }

  354. 

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

  356. {

  357.     AVIContext *avi = s->priv_data;

  358.     AVIOContext *pb = s->pb;

  359.     unsigned int tag, tag1, handler;

  360.     int codec_type, stream_index, frame_period;

  361.     unsigned int size;

  362.     int i;

  363.     AVStream *st;

  364.     AVIStream *ast = NULL;

  365.     int avih_width=0, avih_height=0;

  366.     int amv_file_format=0;

  367.     uint64_t list_end = 0;

  368.     int ret;

  369. 

  370.     avi->stream_index= -1;

  371. 

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

  373.         return -1;

  374. 

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

  376. 

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

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

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

  380. 

  381.     /* first list tag */

  382.     stream_index = -1;

  383.     codec_type = -1;

  384.     frame_period = 0;

  385.     for(;;) {

  386.         if (url_feof(pb))

  387.             goto fail;

  388.         tag = avio_rl32(pb);

  389.         size = avio_rl32(pb);

  390. 

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

  392. 

  393.         switch(tag) {

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

  395.             list_end = avio_tell(pb) + size;

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

  397.             tag1 = avio_rl32(pb);

  398. 

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

  400. 

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

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

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

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

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

  406.                 goto end_of_header;

  407.             }

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

  409.                 avi_read_info(s, list_end);

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

  411.                 avi_read_nikon(s, list_end);

  412. 

  413.             break;

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

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

  416.             size += (size & 1);

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

  418.             avio_skip(pb, size);

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

  420.             break;

  421.         }

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

  423.             avi->is_odml = 1;

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

  425.             break;

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

  427.             amv_file_format=1;

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

  429.             /* AVI header */

  430.             /* using frame_period is bad idea */

  431.             frame_period = avio_rl32(pb);

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

  433.             avio_rl32(pb);

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

  435. 

  436.             avio_skip(pb, 2 * 4);

  437.             avio_rl32(pb);

  438.             avio_rl32(pb);

  439.             avih_width=avio_rl32(pb);

  440.             avih_height=avio_rl32(pb);

  441. 

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

  443.             break;

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

  445.             /* stream header */

  446. 

  447.             tag1 = avio_rl32(pb);

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

  449. 

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

  451.                 avio_skip(pb, size - 8);

  452.                 break;

  453.             }else{

  454.                 stream_index++;

  455.                 st = av_new_stream(s, stream_index);

  456.                 if (!st)

  457.                     goto fail;

  458. 

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

  460.                 if (!ast)

  461.                     goto fail;

  462.                 st->priv_data = ast;

  463.             }

  464.             if(amv_file_format)

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

  466. 

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

  468. 

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

  470.                 int64_t dv_dur;

  471. 

  472.                 /*

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

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

  475.                  */

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

  477.                     goto fail;

  478. 

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

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

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

  482.                    goto fail;

  483. 

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

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

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

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

  488.                 s->nb_streams = 0;

  489.                 if (CONFIG_DV_DEMUXER) {

  490.                     avi->dv_demux = 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.             assert(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.             av_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.             ast->sample_size = avio_rl32(pb); /* sample ssize */

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

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

  545. 

  546.             switch(tag1) {

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

  548.                 codec_type = AVMEDIA_TYPE_VIDEO;

  549. 

  550.                 ast->sample_size = 0;

  551.                 break;

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

  553.                 codec_type = AVMEDIA_TYPE_AUDIO;

  554.                 break;

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

  556.                 codec_type = AVMEDIA_TYPE_SUBTITLE;

  557.                 break;

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

  559.                 codec_type = AVMEDIA_TYPE_DATA;

  560.                 break;

  561.             default:

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

  563.                 goto fail;

  564.             }

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

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

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

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

  569.             break;

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

  571.             /* stream header */

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

  573.                 avio_skip(pb, size);

  574.             } else {

  575.                 uint64_t cur_pos = avio_tell(pb);

  576.                 if (cur_pos < list_end)

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

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

  579.                 switch(codec_type) {

  580.                 case AVMEDIA_TYPE_VIDEO:

  581.                     if(amv_file_format){

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

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

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

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

  586.                         avio_skip(pb, size);

  587.                         break;

  588.                     }

  589.                     tag1 = ff_get_bmp_header(pb, st);

  590. 

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

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

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

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

  595.                         break;

  596.                     }

  597. 

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

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

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

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

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

  603.                             return AVERROR(ENOMEM);

  604.                         }

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

  606.                     }

  607. 

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

  609.                         avio_r8(pb);

  610. 

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

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

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

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

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

  616.                         const uint8_t *pal_src;

  617. 

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

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

  620. #if HAVE_BIGENDIAN

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

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

  623. #else

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

  625. #endif

  626.                         ast->has_pal = 1;

  627.                     }

  628. 

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

  630. 

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

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

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

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

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

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

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

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

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

  640. 

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

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

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

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

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

  646.                     }

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

  648. 

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

  650.                     break;

  651.                 case AVMEDIA_TYPE_AUDIO:

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

  653.                     if (ret < 0)

  654.                         return ret;

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

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

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

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

  659.                     }

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

  661.                         avio_skip(pb, 1);

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

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

  664.                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;

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

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

  667.                      * fail. */

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

  669.                         st->need_parsing = AVSTREAM_PARSE_NONE;

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

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

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

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

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

  675.                     }

  676.                     if (amv_file_format){

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

  678.                         ast->dshow_block_align = 0;

  679.                     }

  680.                     break;

  681.                 case AVMEDIA_TYPE_SUBTITLE:

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

  683.                     st->request_probe= 1;

  684.                     break;

  685.                 default:

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

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

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

  689.                     avio_skip(pb, size);

  690.                     break;

  691.                 }

  692.             }

  693.             break;

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

  695.             i= avio_tell(pb);

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

  697.                 read_braindead_odml_indx(s, 0);

  698.             }

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

  700.             break;

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

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

  703.                 AVRational active, active_aspect;

  704. 

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

  706.                 avio_rl32(pb);

  707.                 avio_rl32(pb);

  708.                 avio_rl32(pb);

  709.                 avio_rl32(pb);

  710.                 avio_rl32(pb);

  711. 

  712.                 active_aspect.den= avio_rl16(pb);

  713.                 active_aspect.num= avio_rl16(pb);

  714.                 active.num       = avio_rl32(pb);

  715.                 active.den       = avio_rl32(pb);

  716.                 avio_rl32(pb); //nbFieldsPerFrame

  717. 

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

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

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

  721.                 }

  722.                 size -= 9*4;

  723.             }

  724.             avio_skip(pb, size);

  725.             break;

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

  727.             if(s->nb_streams){

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

  729.                 break;

  730.             }

  731.         default:

  732.             if(size > 1000000){

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

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

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

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

  737.                 goto end_of_header;

  738.             }

  739.             /* skip tag */

  740.             size += (size & 1);

  741.             avio_skip(pb, size);

  742.             break;

  743.         }

  744.     }

  745.  end_of_header:

  746.     /* check stream number */

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

  748.     fail:

  749.         return -1;

  750.     }

  751. 

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

  753.         avi_load_index(s);

  754.     avi->index_loaded = 1;

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

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

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

  758.         if(st->nb_index_entries)

  759.             break;

  760.     }

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

  762.     // a mis-detection.

  763.     if(avi->dv_demux)

  764.         avi->non_interleaved=0;

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

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

  767.         avi->non_interleaved=0;

  768.     }

  769. 

  770.     if(avi->non_interleaved) {

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

  772.         clean_index(s);

  773.     }

  774. 

  775.     ff_metadata_conv_ctx(s, NULL, ff_avi_metadata_conv);

  776. 

  777.     return 0;

  778. }

  779. 

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

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

  782.         uint8_t desc[256];

  783.         int score = AVPROBE_SCORE_MAX / 2, ret;

  784.         AVIStream *ast = st->priv_data;

  785.         AVInputFormat *sub_demuxer;

  786.         AVRational time_base;

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

  788.                                               pkt->size - 7,

  789.                                               0, NULL, NULL, NULL, NULL);

  790.         AVProbeData pd;

  791.         unsigned int desc_len = avio_rl32(pb);

  792. 

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

  794.             goto error;

  795. 

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

  797.         avio_skip(pb, desc_len - ret);

  798.         if (*desc)

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

  800. 

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

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

  803. 

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

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

  806.             goto error;

  807. 

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

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

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

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

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

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

  814.         }

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

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

  817.         return 1;

  818. error:

  819.         av_freep(&pb);

  820.     }

  821.     return 0;

  822. }

  823. 

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

  825.                                   AVPacket *pkt)

  826. {

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

  828.     int64_t ts, next_ts, ts_min = INT64_MAX;

  829.     AVStream *st, *sub_st = NULL;

  830.     int i;

  831. 

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

  833.                            AV_TIME_BASE_Q);

  834. 

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

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

  837.         ast = st->priv_data;

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

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

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

  841.                 ts_min = ts;

  842.                 sub_st = st;

  843.             }

  844.         }

  845.     }

  846. 

  847.     if (sub_st) {

  848.         ast = sub_st->priv_data;

  849.         *pkt = ast->sub_pkt;

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

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

  852.             ast->sub_pkt.data = NULL;

  853.     }

  854.     return sub_st;

  855. }

  856. 

  857. static int get_stream_idx(int *d){

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

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

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

  861.     }else{

  862.         return 100; //invalid stream ID

  863.     }

  864. }

  865. 

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

  867. {

  868.     AVIContext *avi = s->priv_data;

  869.     AVIOContext *pb = s->pb;

  870.     int n, d[8];

  871.     unsigned int size;

  872.     int64_t i, sync;

  873.     void* dstr;

  874. 

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

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

  877.         if (size >= 0)

  878.             return size;

  879.     }

  880. 

  881.     if(avi->non_interleaved){

  882.         int best_stream_index = 0;

  883.         AVStream *best_st= NULL;

  884.         AVIStream *best_ast;

  885.         int64_t best_ts= INT64_MAX;

  886.         int i;

  887. 

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

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

  890.             AVIStream *ast = st->priv_data;

  891.             int64_t ts= ast->frame_offset;

  892.             int64_t last_ts;

  893. 

  894.             if(!st->nb_index_entries)

  895.                 continue;

  896. 

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

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

  899.                 continue;

  900. 

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

  902. 

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

  904.             if(ts < best_ts){

  905.                 best_ts= ts;

  906.                 best_st= st;

  907.                 best_stream_index= i;

  908.             }

  909.         }

  910.         if(!best_st)

  911.             return -1;

  912. 

  913.         best_ast = best_st->priv_data;

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

  915.         if(best_ast->remaining)

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

  917.         else{

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

  919.             if(i>=0)

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

  921.         }

  922. 

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

  924.         if(i>=0){

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

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

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

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

  929. 

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

  931. 

  932.             avi->stream_index= best_stream_index;

  933.             if(!best_ast->remaining)

  934.                 best_ast->packet_size=

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

  936.         }

  937.     }

  938. 

  939. resync:

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

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

  942.         AVIStream *ast= st->priv_data;

  943.         int size, err;

  944. 

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

  946.             return 0;

  947. 

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

  949.             size= INT_MAX;

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

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

  952.             size= 1024*ast->sample_size;

  953.         else

  954.             size= ast->sample_size;

  955. 

  956.         if(size > ast->remaining)

  957.             size= ast->remaining;

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

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

  960.         if(err<0)

  961.             return err;

  962. 

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

  964.             uint8_t *pal;

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

  966.             if(!pal){

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

  968.             }else{

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

  970.                 ast->has_pal = 0;

  971.             }

  972.         }

  973. 

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

  975.             dstr = pkt->destruct;

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

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

  978.             pkt->destruct = dstr;

  979.             pkt->flags |= AV_PKT_FLAG_KEY;

  980.             if (size < 0)

  981.                 av_free_packet(pkt);

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

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

  984.             ast->frame_offset++;

  985.             avi->stream_index = -1;

  986.             ast->remaining = 0;

  987.             goto resync;

  988.         } else {

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

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

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

  992.             if(ast->sample_size)

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

  994. //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);

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

  996. 

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

  998.                 AVIndexEntry *e;

  999.                 int index;

  1000.                 assert(st->index_entries);

  1001. 

  1002.                 index= av_index_search_timestamp(st, ast->frame_offset, 0);

  1003.                 e= &st->index_entries[index];

  1004. 

  1005.                 if(index >= 0 && e->timestamp == ast->frame_offset){

  1006.                     if (index == st->nb_index_entries-1){

  1007.                         int key=1;

  1008.                         int i;

  1009.                         uint32_t state=-1;

  1010.                         for(i=0; i<FFMIN(size,256); i++){

  1011.                             if(st->codec->codec_id == CODEC_ID_MPEG4){

  1012.                                 if(state == 0x1B6){

  1013.                                     key= !(pkt->data[i]&0xC0);

  1014.                                     break;

  1015.                                 }

  1016.                             }else

  1017.                                 break;

  1018.                             state= (state<<8) + pkt->data[i];

  1019.                         }

  1020.                         if(!key)

  1021.                             e->flags &= ~AVINDEX_KEYFRAME;

  1022.                     }

  1023.                     if (e->flags & AVINDEX_KEYFRAME)

  1024.                         pkt->flags |= AV_PKT_FLAG_KEY;

  1025.                 }

  1026.             } else {

  1027.                 pkt->flags |= AV_PKT_FLAG_KEY;

  1028.             }

  1029.             ast->frame_offset += get_duration(ast, pkt->size);

  1030.         }

  1031.         ast->remaining -= size;

  1032.         if(!ast->remaining){

  1033.             avi->stream_index= -1;

  1034.             ast->packet_size= 0;

  1035.         }

  1036. 

  1037.         if(!avi->non_interleaved && pkt->pos >= 0 && ast->seek_pos > pkt->pos){

  1038.             av_free_packet(pkt);

  1039.             goto resync;

  1040.         }

  1041.         ast->seek_pos= 0;

  1042. 

  1043.         return size;

  1044.     }

  1045. 

  1046.     memset(d, -1, sizeof(int)*8);

  1047.     for(i=sync=avio_tell(pb); !url_feof(pb); i++) {

  1048.         int j;

  1049. 

  1050.         for(j=0; j<7; j++)

  1051.             d[j]= d[j+1];

  1052.         d[7]= avio_r8(pb);

  1053. 

  1054.         size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);

  1055. 

  1056.         n= get_stream_idx(d+2);

  1057. //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);

  1058.         if(i + (uint64_t)size > avi->fsize || d[0]<0)

  1059.             continue;

  1060. 

  1061.         //parse ix##

  1062.         if(  (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)

  1063.         //parse JUNK

  1064.            ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')

  1065.            ||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){

  1066.             avio_skip(pb, size);

  1067. //av_log(s, AV_LOG_DEBUG, "SKIP\n");

  1068.             goto resync;

  1069.         }

  1070. 

  1071.         //parse stray LIST

  1072.         if(d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T'){

  1073.             avio_skip(pb, 4);

  1074.             goto resync;

  1075.         }

  1076. 

  1077.         n= get_stream_idx(d);

  1078. 

  1079.         if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)

  1080.             continue;

  1081. 

  1082.         //detect ##ix chunk and skip

  1083.         if(d[2] == 'i' && d[3] == 'x' && n < s->nb_streams){

  1084.             avio_skip(pb, size);

  1085.             goto resync;

  1086.         }

  1087. 

  1088.         //parse ##dc/##wb

  1089.         if(n < s->nb_streams){

  1090.             AVStream *st;

  1091.             AVIStream *ast;

  1092.             st = s->streams[n];

  1093.             ast = st->priv_data;

  1094. 

  1095.             if(s->nb_streams>=2){

  1096.                 AVStream *st1  = s->streams[1];

  1097.                 AVIStream *ast1= st1->priv_data;

  1098.                 //workaround for broken small-file-bug402.avi

  1099.                 if(   d[2] == 'w' && d[3] == 'b'

  1100.                    && n==0

  1101.                    && st ->codec->codec_type == AVMEDIA_TYPE_VIDEO

  1102.                    && st1->codec->codec_type == AVMEDIA_TYPE_AUDIO

  1103.                    && ast->prefix == 'd'*256+'c'

  1104.                    && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)

  1105.                   ){

  1106.                     n=1;

  1107.                     st = st1;

  1108.                     ast = ast1;

  1109.                     av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");

  1110.                 }

  1111.             }

  1112. 

  1113. 

  1114.             if(   (st->discard >= AVDISCARD_DEFAULT && size==0)

  1115.                /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & AV_PKT_FLAG_KEY))*/ //FIXME needs a little reordering

  1116.                || st->discard >= AVDISCARD_ALL){

  1117.                 ast->frame_offset += get_duration(ast, size);

  1118.                 avio_skip(pb, size);

  1119.                 goto resync;

  1120.             }

  1121. 

  1122.             if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {

  1123.                 int k = avio_r8(pb);

  1124.                 int last = (k + avio_r8(pb) - 1) & 0xFF;

  1125. 

  1126.                 avio_rl16(pb); //flags

  1127. 

  1128.                 for (; k <= last; k++)

  1129.                     ast->pal[k] = avio_rb32(pb)>>8;// b + (g << 8) + (r << 16);

  1130.                 ast->has_pal= 1;

  1131.                 goto resync;

  1132.             } else if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||

  1133.                          d[2]*256+d[3] == ast->prefix /*||

  1134.                          (d[2] == 'd' && d[3] == 'c') ||

  1135.                          (d[2] == 'w' && d[3] == 'b')*/) {

  1136. 

  1137. //av_log(s, AV_LOG_DEBUG, "OK\n");

  1138.                 if(d[2]*256+d[3] == ast->prefix)

  1139.                     ast->prefix_count++;

  1140.                 else{

  1141.                     ast->prefix= d[2]*256+d[3];

  1142.                     ast->prefix_count= 0;

  1143.                 }

  1144. 

  1145.                 avi->stream_index= n;

  1146.                 ast->packet_size= size + 8;

  1147.                 ast->remaining= size;

  1148. 

  1149.                 if(size || !ast->sample_size){

  1150.                     uint64_t pos= avio_tell(pb) - 8;

  1151.                     if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){

  1152.                         av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);

  1153.                     }

  1154.                 }

  1155.                 goto resync;

  1156.             }

  1157.         }

  1158.     }

  1159. 

  1160.     return AVERROR_EOF;

  1161. }

  1162. 

  1163. /* XXX: We make the implicit supposition that the positions are sorted

  1164.    for each stream. */

  1165. static int avi_read_idx1(AVFormatContext *s, int size)

  1166. {

  1167.     AVIContext *avi = s->priv_data;

  1168.     AVIOContext *pb = s->pb;

  1169.     int nb_index_entries, i;

  1170.     AVStream *st;

  1171.     AVIStream *ast;

  1172.     unsigned int index, tag, flags, pos, len;

  1173.     unsigned last_pos= -1;

  1174. 

  1175.     nb_index_entries = size / 16;

  1176.     if (nb_index_entries <= 0)

  1177.         return -1;

  1178. 

  1179.     /* Read the entries and sort them in each stream component. */

  1180.     for(i = 0; i < nb_index_entries; i++) {

  1181.         tag = avio_rl32(pb);

  1182.         flags = avio_rl32(pb);

  1183.         pos = avio_rl32(pb);

  1184.         len = avio_rl32(pb);

  1185. #if defined(DEBUG_SEEK)

  1186.         av_log(s, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",

  1187.                i, tag, flags, pos, len);

  1188. #endif

  1189.         if(i==0 && pos > avi->movi_list)

  1190.             avi->movi_list= 0; //FIXME better check

  1191.         pos += avi->movi_list;

  1192. 

  1193.         index = ((tag & 0xff) - '0') * 10;

  1194.         index += ((tag >> 8) & 0xff) - '0';

  1195.         if (index >= s->nb_streams)

  1196.             continue;

  1197.         st = s->streams[index];

  1198.         ast = st->priv_data;

  1199. 

  1200. #if defined(DEBUG_SEEK)

  1201.         av_log(s, AV_LOG_DEBUG, "%d cum_len=%"PRId64"\n", len, ast->cum_len);

  1202. #endif

  1203.         if(url_feof(pb))

  1204.             return -1;

  1205. 

  1206.         if(last_pos == pos)

  1207.             avi->non_interleaved= 1;

  1208.         else if(len || !ast->sample_size)

  1209.             av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);

  1210.         ast->cum_len += get_duration(ast, len);

  1211.         last_pos= pos;

  1212.     }

  1213.     return 0;

  1214. }

  1215. 

  1216. static int guess_ni_flag(AVFormatContext *s){

  1217.     int i;

  1218.     int64_t last_start=0;

  1219.     int64_t first_end= INT64_MAX;

  1220.     int64_t oldpos= avio_tell(s->pb);

  1221. 

  1222.     for(i=0; i<s->nb_streams; i++){

  1223.         AVStream *st = s->streams[i];

  1224.         int n= st->nb_index_entries;

  1225.         unsigned int size;

  1226. 

  1227.         if(n <= 0)

  1228.             continue;

  1229. 

  1230.         if(n >= 2){

  1231.             int64_t pos= st->index_entries[0].pos;

  1232.             avio_seek(s->pb, pos + 4, SEEK_SET);

  1233.             size= avio_rl32(s->pb);

  1234.             if(pos + size > st->index_entries[1].pos)

  1235.                 last_start= INT64_MAX;

  1236.         }

  1237. 

  1238.         if(st->index_entries[0].pos > last_start)

  1239.             last_start= st->index_entries[0].pos;

  1240.         if(st->index_entries[n-1].pos < first_end)

  1241.             first_end= st->index_entries[n-1].pos;

  1242.     }

  1243.     avio_seek(s->pb, oldpos, SEEK_SET);

  1244.     return last_start > first_end;

  1245. }

  1246. 

  1247. static int avi_load_index(AVFormatContext *s)

  1248. {

  1249.     AVIContext *avi = s->priv_data;

  1250.     AVIOContext *pb = s->pb;

  1251.     uint32_t tag, size;

  1252.     int64_t pos= avio_tell(pb);

  1253.     int ret = -1;

  1254. 

  1255.     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)

  1256.         goto the_end; // maybe truncated file

  1257. #ifdef DEBUG_SEEK

  1258.     av_log(s, AV_LOG_DEBUG, "movi_end=0x%"PRIx64"\n", avi->movi_end);

  1259. #endif

  1260.     for(;;) {

  1261.         if (url_feof(pb))

  1262.             break;

  1263.         tag = avio_rl32(pb);

  1264.         size = avio_rl32(pb);

  1265. #ifdef DEBUG_SEEK

  1266.         av_log(s, AV_LOG_DEBUG, "tag=%c%c%c%c size=0x%x\n",

  1267.                tag & 0xff,

  1268.                (tag >> 8) & 0xff,

  1269.                (tag >> 16) & 0xff,

  1270.                (tag >> 24) & 0xff,

  1271.                size);

  1272. #endif

  1273.         switch(tag) {

  1274.         case MKTAG('i', 'd', 'x', '1'):

  1275.             if (avi_read_idx1(s, size) < 0)

  1276.                 goto skip;

  1277.             ret = 0;

  1278.                 goto the_end;

  1279.             break;

  1280.         default:

  1281.         skip:

  1282.             size += (size & 1);

  1283.             if (avio_skip(pb, size) < 0)

  1284.                 goto the_end; // something is wrong here

  1285.             break;

  1286.         }

  1287.     }

  1288.  the_end:

  1289.     avio_seek(pb, pos, SEEK_SET);

  1290.     return ret;

  1291. }

  1292. 

  1293. static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)

  1294. {

  1295.     AVIStream *ast2 = st2->priv_data;

  1296.     int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);

  1297.     av_free_packet(&ast2->sub_pkt);

  1298.     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||

  1299.         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)

  1300.         av_read_packet(ast2->sub_ctx, &ast2->sub_pkt);

  1301. }

  1302. 

  1303. static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

  1304. {

  1305.     AVIContext *avi = s->priv_data;

  1306.     AVStream *st;

  1307.     int i, index;

  1308.     int64_t pos, pos_min;

  1309.     AVIStream *ast;

  1310. 

  1311.     if (!avi->index_loaded) {

  1312.         /* we only load the index on demand */

  1313.         avi_load_index(s);

  1314.         avi->index_loaded = 1;

  1315.     }

  1316.     assert(stream_index>= 0);

  1317. 

  1318.     st = s->streams[stream_index];

  1319.     ast= st->priv_data;

  1320.     index= av_index_search_timestamp(st, timestamp * FFMAX(ast->sample_size, 1), flags);

  1321.     if(index<0)

  1322.         return -1;

  1323. 

  1324.     /* find the position */

  1325.     pos = st->index_entries[index].pos;

  1326.     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);

  1327. 

  1328. //    av_log(s, AV_LOG_DEBUG, "XX %"PRId64" %d %"PRId64"\n", timestamp, index, st->index_entries[index].timestamp);

  1329. 

  1330.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1331.         /* One and only one real stream for DV in AVI, and it has video  */

  1332.         /* offsets. Calling with other stream indexes should have failed */

  1333.         /* the av_index_search_timestamp call above.                     */

  1334.         assert(stream_index == 0);

  1335. 

  1336.         /* Feed the DV video stream version of the timestamp to the */

  1337.         /* DV demux so it can synthesize correct timestamps.        */

  1338.         dv_offset_reset(avi->dv_demux, timestamp);

  1339. 

  1340.         avio_seek(s->pb, pos, SEEK_SET);

  1341.         avi->stream_index= -1;

  1342.         return 0;

  1343.     }

  1344. 

  1345.     pos_min= pos;

  1346.     for(i = 0; i < s->nb_streams; i++) {

  1347.         AVStream *st2 = s->streams[i];

  1348.         AVIStream *ast2 = st2->priv_data;

  1349. 

  1350.         ast2->packet_size=

  1351.         ast2->remaining= 0;

  1352. 

  1353.         if (ast2->sub_ctx) {

  1354.             seek_subtitle(st, st2, timestamp);

  1355.             continue;

  1356.         }

  1357. 

  1358.         if (st2->nb_index_entries <= 0)

  1359.             continue;

  1360. 

  1361. //        assert(st2->codec->block_align);

  1362.         assert((int64_t)st2->time_base.num*ast2->rate == (int64_t)st2->time_base.den*ast2->scale);

  1363.         index = av_index_search_timestamp(

  1364.                 st2,

  1365.                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),

  1366.                 flags | AVSEEK_FLAG_BACKWARD);

  1367.         if(index<0)

  1368.             index=0;

  1369.         ast2->seek_pos= st2->index_entries[index].pos;

  1370.         pos_min= FFMIN(pos_min,ast2->seek_pos);

  1371.     }

  1372.     for(i = 0; i < s->nb_streams; i++) {

  1373.         AVStream *st2 = s->streams[i];

  1374.         AVIStream *ast2 = st2->priv_data;

  1375. 

  1376.         if (ast2->sub_ctx || st2->nb_index_entries <= 0)

  1377.             continue;

  1378. 

  1379.         index = av_index_search_timestamp(

  1380.                 st2,

  1381.                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),

  1382.                 flags | AVSEEK_FLAG_BACKWARD);

  1383.         if(index<0)

  1384.             index=0;

  1385.         while(index>0 && st2->index_entries[index-1].pos >= pos_min)

  1386.             index--;

  1387.         ast2->frame_offset = st2->index_entries[index].timestamp;

  1388.     }

  1389. 

  1390.     /* do the seek */

  1391.     avio_seek(s->pb, pos_min, SEEK_SET);

  1392.     avi->stream_index= -1;

  1393.     return 0;

  1394. }

  1395. 

  1396. static int avi_read_close(AVFormatContext *s)

  1397. {

  1398.     int i;

  1399.     AVIContext *avi = s->priv_data;

  1400. 

  1401.     for(i=0;i<s->nb_streams;i++) {

  1402.         AVStream *st = s->streams[i];

  1403.         AVIStream *ast = st->priv_data;

  1404.         if (ast) {

  1405.             if (ast->sub_ctx) {

  1406.                 av_freep(&ast->sub_ctx->pb);

  1407.                 av_close_input_stream(ast->sub_ctx);

  1408.             }

  1409.             av_free(ast->sub_buffer);

  1410.             av_free_packet(&ast->sub_pkt);

  1411.         }

  1412.     }

  1413. 

  1414.     av_free(avi->dv_demux);

  1415. 

  1416.     return 0;

  1417. }

  1418. 

  1419. static int avi_probe(AVProbeData *p)

  1420. {

  1421.     int i;

  1422. 

  1423.     /* check file header */

  1424.     for(i=0; avi_headers[i][0]; i++)

  1425.         if(!memcmp(p->buf  , avi_headers[i]  , 4) &&

  1426.            !memcmp(p->buf+8, avi_headers[i]+4, 4))

  1427.             return AVPROBE_SCORE_MAX;

  1428. 

  1429.     return 0;

  1430. }

  1431. 

  1432. AVInputFormat ff_avi_demuxer = {

  1433.     "avi",

  1434.     NULL_IF_CONFIG_SMALL("AVI format"),

  1435.     sizeof(AVIContext),

  1436.     avi_probe,

  1437.     avi_read_header,

  1438.     avi_read_packet,

  1439.     avi_read_close,

  1440.     avi_read_seek,

  1441.     .priv_class = &demuxer_class,

  1442. };