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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. #include <inttypes.h>

  23. 

  24. #include "libavutil/avstring.h"

  25. #include "libavutil/bswap.h"

  26. #include "libavutil/dict.h"

  27. #include "libavutil/internal.h"

  28. #include "libavutil/intreadwrite.h"

  29. #include "libavutil/mathematics.h"

  30. #include "avformat.h"

  31. #include "avi.h"

  32. #include "dv.h"

  33. #include "internal.h"

  34. #include "isom.h"

  35. #include "riff.h"

  36. 

  37. #undef NDEBUG

  38. #include <assert.h>

  39. 

  40. typedef struct AVIStream {

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

  42.                              * (used to compute the pts) */

  43.     int remaining;

  44.     int packet_size;

  45. 

  46.     uint32_t handler;

  47.     uint32_t scale;

  48.     uint32_t rate;

  49.     int sample_size;        /* size of one sample (or packet)

  50.                              * (in the rate/scale sense) in bytes */

  51. 

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

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

  54.     int prefix_count;

  55.     uint32_t pal[256];

  56.     int has_pal;

  57.     int dshow_block_align;  /* block align variable used to emulate bugs in

  58.                              * the MS dshow demuxer */

  59. 

  60.     AVFormatContext *sub_ctx;

  61.     AVPacket sub_pkt;

  62.     uint8_t *sub_buffer;

  63. } AVIStream;

  64. 

  65. typedef struct AVIContext {

  66.     int64_t riff_end;

  67.     int64_t movi_end;

  68.     int64_t fsize;

  69.     int64_t movi_list;

  70.     int64_t last_pkt_pos;

  71.     int index_loaded;

  72.     int is_odml;

  73.     int non_interleaved;

  74.     int stream_index;

  75.     DVDemuxContext *dv_demux;

  76.     int odml_depth;

  77. #define MAX_ODML_DEPTH 1000

  78. } AVIContext;

  79. 

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

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

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

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

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

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

  86.     { 0 }

  87. };

  88. 

  89. static const AVMetadataConv avi_metadata_conv[] = {

  90.     { "strn", "title" },

  91.     { 0 },

  92. };

  93. 

  94. static int avi_load_index(AVFormatContext *s);

  95. static int guess_ni_flag(AVFormatContext *s);

  96. 

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

  98.     av_log(NULL, AV_LOG_TRACE, "%s: tag=%c%c%c%c size=0x%x\n",        \

  99.             str, tag & 0xff,                             \

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

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

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

  103.             size)

  104. 

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

  106. {

  107.     if (ast->sample_size)

  108.         return len;

  109.     else if (ast->dshow_block_align)

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

  111.     else

  112.         return 1;

  113. }

  114. 

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

  116. {

  117.     AVIContext *avi = s->priv_data;

  118.     char header[8];

  119.     int i;

  120. 

  121.     /* check RIFF header */

  122.     avio_read(pb, header, 4);

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

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

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

  126. 

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

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

  129.             break;

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

  131.         return AVERROR_INVALIDDATA;

  132. 

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

  134.         av_log(s, AV_LOG_INFO,

  135.                "This file has been generated by a totally broken muxer.\n");

  136. 

  137.     return 0;

  138. }

  139. 

  140. static int read_braindead_odml_indx(AVFormatContext *s, int frame_num)

  141. {

  142.     AVIContext *avi     = s->priv_data;

  143.     AVIOContext *pb     = s->pb;

  144.     int longs_pre_entry = avio_rl16(pb);

  145.     int index_sub_type  = avio_r8(pb);

  146.     int index_type      = avio_r8(pb);

  147.     int entries_in_use  = avio_rl32(pb);

  148.     int chunk_id        = avio_rl32(pb);

  149.     int64_t base        = avio_rl64(pb);

  150.     int stream_id       = ((chunk_id      & 0xFF) - '0') * 10 +

  151.                           ((chunk_id >> 8 & 0xFF) - '0');

  152.     AVStream *st;

  153.     AVIStream *ast;

  154.     int i;

  155.     int64_t last_pos = -1;

  156.     int64_t filesize = avi->fsize;

  157. 

  158.     av_log(s, AV_LOG_TRACE,

  159.             "longs_pre_entry:%d index_type:%d entries_in_use:%d "

  160.             "chunk_id:%X base:%16"PRIX64"\n",

  161.             longs_pre_entry,

  162.             index_type,

  163.             entries_in_use,

  164.             chunk_id,

  165.             base);

  166. 

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

  168.         return AVERROR_INVALIDDATA;

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

  170.     ast = st->priv_data;

  171. 

  172.     if (index_sub_type)

  173.         return AVERROR_INVALIDDATA;

  174. 

  175.     avio_rl32(pb);

  176. 

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

  178.         return AVERROR_INVALIDDATA;

  179.     if (index_type > 1)

  180.         return AVERROR_INVALIDDATA;

  181. 

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

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

  184.         if (base >> 32 == (base & 0xFFFFFFFF) &&

  185.             (base & 0xFFFFFFFF) < filesize    &&

  186.             filesize <= 0xFFFFFFFF)

  187.             base &= 0xFFFFFFFF;

  188.         else

  189.             return AVERROR_INVALIDDATA;

  190.     }

  191. 

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

  193.         if (index_type) {

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

  195.             int len     = avio_rl32(pb);

  196.             int key     = len >= 0;

  197.             len &= 0x7FFFFFFF;

  198. 

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

  200. 

  201.             if (pb->eof_reached)

  202.                 return AVERROR_INVALIDDATA;

  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,

  208.                                    key ? AVINDEX_KEYFRAME : 0);

  209. 

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

  211.             last_pos      = pos;

  212.         } else {

  213.             int64_t offset, pos;

  214.             int duration;

  215.             offset = avio_rl64(pb);

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

  217.             duration = avio_rl32(pb);

  218. 

  219.             if (pb->eof_reached)

  220.                 return AVERROR_INVALIDDATA;

  221. 

  222.             pos = avio_tell(pb);

  223. 

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

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

  226.                 return AVERROR_INVALIDDATA;

  227.             }

  228. 

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

  230.             avi->odml_depth++;

  231.             read_braindead_odml_indx(s, frame_num);

  232.             avi->odml_depth--;

  233.             frame_num += duration;

  234. 

  235.             avio_seek(pb, pos, SEEK_SET);

  236.         }

  237.     }

  238.     avi->index_loaded = 1;

  239.     return 0;

  240. }

  241. 

  242. static void clean_index(AVFormatContext *s)

  243. {

  244.     int i;

  245.     int64_t j;

  246. 

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

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

  249.         AVIStream *ast = st->priv_data;

  250.         int n          = st->nb_index_entries;

  251.         int max        = ast->sample_size;

  252.         int64_t pos, size, ts;

  253. 

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

  255.             continue;

  256. 

  257.         while (max < 1024)

  258.             max += max;

  259. 

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

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

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

  263. 

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

  265.             av_add_index_entry(st, pos + j, ts + j, FFMIN(max, size - j), 0,

  266.                                AVINDEX_KEYFRAME);

  267.     }

  268. }

  269. 

  270. static int avi_read_tag(AVFormatContext *s, AVStream *st, uint32_t tag,

  271.                         uint32_t size)

  272. {

  273.     AVIOContext *pb = s->pb;

  274.     char key[5]     = { 0 };

  275.     char *value;

  276. 

  277.     size += (size & 1);

  278. 

  279.     if (size == UINT_MAX)

  280.         return AVERROR(EINVAL);

  281.     value = av_malloc(size + 1);

  282.     if (!value)

  283.         return AVERROR(ENOMEM);

  284.     avio_read(pb, value, size);

  285.     value[size] = 0;

  286. 

  287.     AV_WL32(key, tag);

  288. 

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

  290.                        AV_DICT_DONT_STRDUP_VAL);

  291. }

  292. 

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

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

  295. 

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

  297. {

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

  299.     int i, day, year;

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

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

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

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

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

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

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

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

  308.             }

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

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

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

  312.     }

  313. }

  314. 

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

  316. {

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

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

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

  320.         switch (tag) {

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

  322.         {

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

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

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

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

  327.                 const char *name = NULL;

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

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

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

  331.                 switch (tag) {

  332.                 case 0x03:

  333.                     name = "maker";

  334.                     break;

  335.                 case 0x04:

  336.                     name = "model";

  337.                     break;

  338.                 case 0x13:

  339.                     name = "creation_time";

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

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

  342.                     break;

  343.                 }

  344.                 if (name)

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

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

  347.             }

  348.             break;

  349.         }

  350.         default:

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

  352.             break;

  353.         }

  354.     }

  355. }

  356. 

  357. static int avi_read_header(AVFormatContext *s)

  358. {

  359.     AVIContext *avi = s->priv_data;

  360.     AVIOContext *pb = s->pb;

  361.     unsigned int tag, tag1, handler;

  362.     int codec_type, stream_index, frame_period;

  363.     unsigned int size;

  364.     int i;

  365.     AVStream *st;

  366.     AVIStream *ast      = NULL;

  367.     int avih_width      = 0, avih_height = 0;

  368.     int amv_file_format = 0;

  369.     uint64_t list_end   = 0;

  370.     int64_t pos;

  371.     int ret;

  372. 

  373.     avi->stream_index = -1;

  374. 

  375.     ret = get_riff(s, pb);

  376.     if (ret < 0)

  377.         return ret;

  378. 

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

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

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

  382. 

  383.     /* first list tag */

  384.     stream_index = -1;

  385.     codec_type   = -1;

  386.     frame_period = 0;

  387.     for (;;) {

  388.         if (pb->eof_reached)

  389.             goto fail;

  390.         tag  = avio_rl32(pb);

  391.         size = avio_rl32(pb);

  392. 

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

  394. 

  395.         switch (tag) {

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

  397.             list_end = avio_tell(pb) + size;

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

  399.             tag1 = avio_rl32(pb);

  400. 

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

  402. 

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

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

  405.                 if (size)

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

  407.                 else

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

  409.                 av_log(NULL, AV_LOG_TRACE, "movi end=%"PRIx64"\n", avi->movi_end);

  410.                 goto end_of_header;

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

  412.                 ff_read_riff_info(s, size - 4);

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

  414.                 avi_read_nikon(s, list_end);

  415. 

  416.             break;

  417.         case MKTAG('I', 'D', 'I', 'T'):

  418.         {

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

  420.             size += (size & 1);

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

  422.             avio_skip(pb, size);

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

  424.             break;

  425.         }

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

  427.             avi->is_odml = 1;

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

  429.             break;

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

  431.             amv_file_format = 1;

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

  433.             /* AVI header */

  434.             /* using frame_period is bad idea */

  435.             frame_period = avio_rl32(pb);

  436.             avio_skip(pb, 4);

  437.             avio_rl32(pb);

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

  439. 

  440.             avio_skip(pb, 2 * 4);

  441.             avio_rl32(pb);

  442.             avio_rl32(pb);

  443.             avih_width  = avio_rl32(pb);

  444.             avih_height = avio_rl32(pb);

  445. 

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

  447.             break;

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

  449.             /* stream header */

  450. 

  451.             tag1    = avio_rl32(pb);

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

  453. 

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

  455.                 avio_skip(pb, size - 8);

  456.                 break;

  457.             } else {

  458.                 stream_index++;

  459.                 st = avformat_new_stream(s, NULL);

  460.                 if (!st)

  461.                     goto fail;

  462. 

  463.                 st->id = stream_index;

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

  465.                 if (!ast)

  466.                     goto fail;

  467.                 st->priv_data = ast;

  468.             }

  469.             if (amv_file_format)

  470.                 tag1 = stream_index ? MKTAG('a', 'u', 'd', 's')

  471.                                     : MKTAG('v', 'i', 'd', 's');

  472. 

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

  474. 

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

  476.                 tag1 == MKTAG('i', 'v', 'a', 's')) {

  477.                 int64_t dv_dur;

  478. 

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

  480.                  * have to support anything but DV in type1 AVIs. */

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

  482.                     goto fail;

  483. 

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

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

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

  487.                     goto fail;

  488. 

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

  490.                 av_freep(&s->streams[0]->codecpar->extradata);

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

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

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

  494.                 s->nb_streams = 0;

  495.                 if (CONFIG_DV_DEMUXER) {

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

  497.                     if (!avi->dv_demux)

  498.                         goto fail;

  499.                 } else

  500.                     goto fail;

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

  502.                 avio_skip(pb, 3 * 4);

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

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

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

  506. 

  507.                 dv_dur = avio_rl32(pb);

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

  509.                     dv_dur     *= AV_TIME_BASE;

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

  511.                 }

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

  513.                  * will make a guess based on bitrate. */

  514. 

  515.                 stream_index = s->nb_streams - 1;

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

  517.                 break;

  518.             }

  519. 

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

  521.             ast->handler = handler;

  522. 

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

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

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

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

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

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

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

  530.                 av_log(s, AV_LOG_WARNING,

  531.                        "scale/rate is %"PRIu32"/%"PRIu32" which is invalid. "

  532.                        "(This file has been generated by broken software.)\n",

  533.                        ast->scale,

  534.                        ast->rate);

  535.                 if (frame_period) {

  536.                     ast->rate  = 1000000;

  537.                     ast->scale = frame_period;

  538.                 } else {

  539.                     ast->rate  = 25;

  540.                     ast->scale = 1;

  541.                 }

  542.             }

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

  544. 

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

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

  547. 

  548.             st->start_time = 0;

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

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

  551.             ast->sample_size = avio_rl32(pb); /* sample size */

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

  553.             av_log(s, AV_LOG_TRACE, "%"PRIu32" %"PRIu32" %d\n",

  554.                     ast->rate, ast->scale, ast->sample_size);

  555. 

  556.             switch (tag1) {

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

  558.                 codec_type = AVMEDIA_TYPE_VIDEO;

  559. 

  560.                 ast->sample_size = 0;

  561.                 break;

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

  563.                 codec_type = AVMEDIA_TYPE_AUDIO;

  564.                 break;

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

  566.                 codec_type = AVMEDIA_TYPE_SUBTITLE;

  567.                 break;

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

  569.                 codec_type = AVMEDIA_TYPE_DATA;

  570.                 break;

  571.             default:

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

  573.                 goto fail;

  574.             }

  575. 

  576.             if (ast->sample_size < 0) {

  577.                 if (s->error_recognition & AV_EF_EXPLODE) {

  578.                     av_log(s, AV_LOG_ERROR,

  579.                            "Invalid sample_size %d at stream %d\n",

  580.                            ast->sample_size,

  581.                            stream_index);

  582.                     goto fail;

  583.                 }

  584.                 av_log(s, AV_LOG_WARNING,

  585.                        "Invalid sample_size %d at stream %d "

  586.                        "setting it to 0\n",

  587.                        ast->sample_size,

  588.                        stream_index);

  589.                 ast->sample_size = 0;

  590.             }

  591. 

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

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

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

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

  596.             break;

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

  598.             /* stream header */

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

  600.                 avio_skip(pb, size);

  601.             } else {

  602.                 uint64_t cur_pos = avio_tell(pb);

  603.                 if (cur_pos < list_end)

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

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

  606.                 switch (codec_type) {

  607.                 case AVMEDIA_TYPE_VIDEO:

  608.                     if (amv_file_format) {

  609.                         st->codecpar->width      = avih_width;

  610.                         st->codecpar->height     = avih_height;

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

  612.                         st->codecpar->codec_id   = AV_CODEC_ID_AMV;

  613.                         avio_skip(pb, size);

  614.                         break;

  615.                     }

  616.                     tag1 = ff_get_bmp_header(pb, st, NULL);

  617. 

  618.                     if (tag1 == MKTAG('D', 'X', 'S', 'B') ||

  619.                         tag1 == MKTAG('D', 'X', 'S', 'A')) {

  620.                         st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;

  621.                         st->codecpar->codec_tag  = tag1;

  622.                         st->codecpar->codec_id   = AV_CODEC_ID_XSUB;

  623.                         break;

  624.                     }

  625. 

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

  627.                         st->codecpar->extradata_size = size - 10 * 4;

  628.                         st->codecpar->extradata      = av_malloc(st->codecpar->extradata_size +

  629.                                                                  AV_INPUT_BUFFER_PADDING_SIZE);

  630.                         if (!st->codecpar->extradata) {

  631.                             st->codecpar->extradata_size = 0;

  632.                             return AVERROR(ENOMEM);

  633.                         }

  634.                         avio_read(pb,

  635.                                   st->codecpar->extradata,

  636.                                   st->codecpar->extradata_size);

  637.                     }

  638. 

  639.                     // FIXME: check if the encoder really did this correctly

  640.                     if (st->codecpar->extradata_size & 1)

  641.                         avio_r8(pb);

  642. 

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

  644.                      * This code assumes that extradata contains only palette.

  645.                      * This is true for all paletted codecs implemented in

  646.                      * Libav. */

  647.                     if (st->codecpar->extradata_size &&

  648.                         (st->codecpar->bits_per_coded_sample <= 8)) {

  649.                         int pal_size = (1 << st->codecpar->bits_per_coded_sample) << 2;

  650.                         const uint8_t *pal_src;

  651. 

  652.                         pal_size = FFMIN(pal_size, st->codecpar->extradata_size);

  653.                         pal_src  = st->codecpar->extradata +

  654.                                    st->codecpar->extradata_size - pal_size;

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

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

  657.                         ast->has_pal = 1;

  658.                     }

  659. 

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

  661. 

  662.                     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

  663.                     st->codecpar->codec_tag  = tag1;

  664.                     st->codecpar->codec_id   = ff_codec_get_id(ff_codec_bmp_tags,

  665.                                                             tag1);

  666.                     /* If codec is not found yet, try with the mov tags. */

  667.                     if (!st->codecpar->codec_id) {

  668.                         char tag_buf[32];

  669.                         av_get_codec_tag_string(tag_buf, sizeof(tag_buf), tag1);

  670.                         st->codecpar->codec_id =

  671.                             ff_codec_get_id(ff_codec_movvideo_tags, tag1);

  672.                         if (st->codecpar->codec_id)

  673.                            av_log(s, AV_LOG_WARNING,

  674.                                   "mov tag found in avi (fourcc %s)\n",

  675.                                   tag_buf);

  676.                     }

  677.                     /* This is needed to get the pict type which is necessary

  678.                      * for generating correct pts. */

  679.                     st->need_parsing = AVSTREAM_PARSE_HEADERS;

  680. 

  681.                     if (st->codecpar->codec_id == AV_CODEC_ID_MPEG4 &&

  682.                         ast->handler == MKTAG('X', 'V', 'I', 'D'))

  683.                         st->codecpar->codec_tag = MKTAG('X', 'V', 'I', 'D');

  684. 

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

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

  687.                         st->codecpar->extradata_size >= 31   &&

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

  689.                         st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;

  690. 

  691.                     if (st->codecpar->codec_tag == 0 && st->codecpar->height > 0 &&

  692.                         st->codecpar->extradata_size < 1U << 30) {

  693.                         st->codecpar->extradata_size += 9;

  694.                         if ((ret = av_reallocp(&st->codecpar->extradata,

  695.                                                st->codecpar->extradata_size +

  696.                                                AV_INPUT_BUFFER_PADDING_SIZE)) < 0) {

  697.                             st->codecpar->extradata_size = 0;

  698.                             return ret;

  699.                         } else

  700.                             memcpy(st->codecpar->extradata + st->codecpar->extradata_size - 9,

  701.                                    "BottomUp", 9);

  702.                     }

  703.                     st->codecpar->height = FFABS(st->codecpar->height);

  704. 

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

  706.                     break;

  707.                 case AVMEDIA_TYPE_AUDIO:

  708.                     ret = ff_get_wav_header(s, pb, st->codecpar, size);

  709.                     if (ret < 0)

  710.                         return ret;

  711.                     ast->dshow_block_align = st->codecpar->block_align;

  712.                     if (ast->sample_size && st->codecpar->block_align &&

  713.                         ast->sample_size != st->codecpar->block_align) {

  714.                         av_log(s,

  715.                                AV_LOG_WARNING,

  716.                                "sample size (%d) != block align (%d)\n",

  717.                                ast->sample_size,

  718.                                st->codecpar->block_align);

  719.                         ast->sample_size = st->codecpar->block_align;

  720.                     }

  721.                     /* 2-aligned

  722.                      * (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */

  723.                     if (size & 1)

  724.                         avio_skip(pb, 1);

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

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

  727.                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;

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

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

  730.                      * fail. */

  731.                     if (st->codecpar->codec_id == AV_CODEC_ID_AAC &&

  732.                         st->codecpar->extradata_size)

  733.                         st->need_parsing = AVSTREAM_PARSE_NONE;

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

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

  736.                     if (ast->handler == AV_RL32("Axan")) {

  737.                         st->codecpar->codec_id  = AV_CODEC_ID_XAN_DPCM;

  738.                         st->codecpar->codec_tag = 0;

  739.                     }

  740.                     if (amv_file_format) {

  741.                         st->codecpar->codec_id    = AV_CODEC_ID_ADPCM_IMA_AMV;

  742.                         ast->dshow_block_align = 0;

  743.                     }

  744.                     break;

  745.                 case AVMEDIA_TYPE_SUBTITLE:

  746.                     st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;

  747.                     st->codecpar->codec_id   = AV_CODEC_ID_PROBE;

  748.                     break;

  749.                 default:

  750.                     st->codecpar->codec_type = AVMEDIA_TYPE_DATA;

  751.                     st->codecpar->codec_id   = AV_CODEC_ID_NONE;

  752.                     st->codecpar->codec_tag  = 0;

  753.                     avio_skip(pb, size);

  754.                     break;

  755.                 }

  756.             }

  757.             break;

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

  759.             pos = avio_tell(pb);

  760.             if ((pb->seekable & AVIO_SEEKABLE_NORMAL) &&

  761.                 !(s->flags & AVFMT_FLAG_IGNIDX) &&

  762.                 read_braindead_odml_indx(s, 0) < 0 &&

  763.                 (s->error_recognition & AV_EF_EXPLODE))

  764.                 goto fail;

  765.             avio_seek(pb, pos + size, SEEK_SET);

  766.             break;

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

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

  769.                 AVRational active, active_aspect;

  770. 

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

  772.                 avio_rl32(pb);

  773.                 avio_rl32(pb);

  774.                 avio_rl32(pb);

  775.                 avio_rl32(pb);

  776.                 avio_rl32(pb);

  777. 

  778.                 active_aspect.den = avio_rl16(pb);

  779.                 active_aspect.num = avio_rl16(pb);

  780.                 active.num        = avio_rl32(pb);

  781.                 active.den        = avio_rl32(pb);

  782.                 avio_rl32(pb); // nbFieldsPerFrame

  783. 

  784.                 if (active_aspect.num && active_aspect.den &&

  785.                     active.num && active.den) {

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

  787.                     av_log(s, AV_LOG_TRACE, "vprp %d/%d %d/%d\n",

  788.                             active_aspect.num, active_aspect.den,

  789.                             active.num, active.den);

  790.                 }

  791.                 size -= 9 * 4;

  792.             }

  793.             avio_skip(pb, size);

  794.             break;

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

  796.             if (s->nb_streams) {

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

  798.                 if (ret < 0)

  799.                     return ret;

  800.                 break;

  801.             }

  802.         default:

  803.             if (size > 1000000) {

  804.                 av_log(s, AV_LOG_ERROR,

  805.                        "Something went wrong during header parsing, "

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

  807.                 if (s->error_recognition & AV_EF_EXPLODE)

  808.                     goto fail;

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

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

  811.                 goto end_of_header;

  812.             }

  813.             /* skip tag */

  814.             size += (size & 1);

  815.             avio_skip(pb, size);

  816.             break;

  817.         }

  818.     }

  819. 

  820. end_of_header:

  821.     /* check stream number */

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

  823. 

  824. fail:

  825.         return AVERROR_INVALIDDATA;

  826.     }

  827. 

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

  829.         avi_load_index(s);

  830.     avi->index_loaded     = 1;

  831. 

  832.     if ((ret = guess_ni_flag(s)) < 0)

  833.         return ret;

  834. 

  835.     avi->non_interleaved |= ret;

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

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

  838.         if (st->nb_index_entries)

  839.             break;

  840.     }

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

  842.         av_log(s, AV_LOG_WARNING,

  843.                "Non-interleaved AVI without index, switching to interleaved\n");

  844.         avi->non_interleaved = 0;

  845.     }

  846. 

  847.     if (avi->non_interleaved) {

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

  849.         clean_index(s);

  850.     }

  851. 

  852.     ff_metadata_conv_ctx(s, NULL, avi_metadata_conv);

  853.     ff_metadata_conv_ctx(s, NULL, ff_riff_info_conv);

  854. 

  855.     return 0;

  856. }

  857. 

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

  859. {

  860.     if (pkt->size >= 7 &&

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

  862.         uint8_t desc[256];

  863.         int score      = AVPROBE_SCORE_EXTENSION, ret;

  864.         AVIStream *ast = st->priv_data;

  865.         AVInputFormat *sub_demuxer;

  866.         AVRational time_base;

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

  868.                                              pkt->size - 7,

  869.                                              0, NULL, NULL, NULL, NULL);

  870.         AVProbeData pd;

  871.         unsigned int desc_len = avio_rl32(pb);

  872. 

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

  874.             goto error;

  875. 

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

  877.         avio_skip(pb, desc_len - ret);

  878.         if (*desc)

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

  880. 

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

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

  883. 

  884.         pd = (AVProbeData) { .buf      = pb->buf_ptr,

  885.                              .buf_size = pb->buf_end - pb->buf_ptr };

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

  887.             goto error;

  888. 

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

  890.             goto error;

  891. 

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

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

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

  895.             avcodec_parameters_copy(st->codecpar, ast->sub_ctx->streams[0]->codecpar);

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

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

  898.         }

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

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

  901.         return 1;

  902. 

  903. error:

  904.         avio_context_free(&pb);

  905.     }

  906.     return 0;

  907. }

  908. 

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

  910.                                   AVPacket *pkt)

  911. {

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

  913.     int64_t ts, next_ts, ts_min = INT64_MAX;

  914.     AVStream *st, *sub_st = NULL;

  915.     int i;

  916. 

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

  918.                            AV_TIME_BASE_Q);

  919. 

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

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

  922.         ast = st->priv_data;

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

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

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

  926.                 ts_min = ts;

  927.                 sub_st = st;

  928.             }

  929.         }

  930.     }

  931. 

  932.     if (sub_st) {

  933.         ast               = sub_st->priv_data;

  934.         *pkt              = ast->sub_pkt;

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

  936. 

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

  938.             ast->sub_pkt.data = NULL;

  939.     }

  940.     return sub_st;

  941. }

  942. 

  943. static int get_stream_idx(int *d)

  944. {

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

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

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

  948.     } else {

  949.         return 100; // invalid stream ID

  950.     }

  951. }

  952. 

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

  954. {

  955.     AVIContext *avi = s->priv_data;

  956.     AVIOContext *pb = s->pb;

  957.     int n;

  958.     unsigned int d[8];

  959.     unsigned int size;

  960.     int64_t i, sync;

  961. 

  962. start_sync:

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

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

  965.         int j;

  966. 

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

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

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

  970. 

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

  972. 

  973.         n = get_stream_idx(d + 2);

  974.         av_log(s, AV_LOG_TRACE, "%X %X %X %X %X %X %X %X %"PRId64" %u %d\n",

  975.                 d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);

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

  977.             continue;

  978. 

  979.         // parse ix##

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

  981.             // parse JUNK

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

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

  984.             avio_skip(pb, size);

  985.             goto start_sync;

  986.         }

  987. 

  988.         // parse stray LIST

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

  990.             avio_skip(pb, 4);

  991.             goto start_sync;

  992.         }

  993. 

  994.         n = get_stream_idx(d);

  995. 

  996.         if (!((i - avi->last_pkt_pos) & 1) &&

  997.             get_stream_idx(d + 1) < s->nb_streams)

  998.             continue;

  999. 

  1000.         // detect ##ix chunk and skip

  1001.         if (d[2] == 'i' && d[3] == 'x' && n < s->nb_streams) {

  1002.             avio_skip(pb, size);

  1003.             goto start_sync;

  1004.         }

  1005. 

  1006.         if (avi->dv_demux && n != 0)

  1007.             continue;

  1008. 

  1009.         // parse ##dc/##wb

  1010.         if (n < s->nb_streams) {

  1011.             AVStream *st;

  1012.             AVIStream *ast;

  1013.             st  = s->streams[n];

  1014.             ast = st->priv_data;

  1015. 

  1016.             if (s->nb_streams >= 2) {

  1017.                 AVStream *st1   = s->streams[1];

  1018.                 AVIStream *ast1 = st1->priv_data;

  1019.                 // workaround for broken small-file-bug402.avi

  1020.                 if (d[2] == 'w' && d[3] == 'b' && n == 0 &&

  1021.                     st->codecpar->codec_type  == AVMEDIA_TYPE_VIDEO &&

  1022.                     st1->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&

  1023.                     ast->prefix == 'd' * 256 + 'c' &&

  1024.                     (d[2] * 256 + d[3] == ast1->prefix ||

  1025.                      !ast1->prefix_count)) {

  1026.                     n   = 1;

  1027.                     st  = st1;

  1028.                     ast = ast1;

  1029.                     av_log(s, AV_LOG_WARNING,

  1030.                            "Invalid stream + prefix combination, assuming audio.\n");

  1031.                 }

  1032.             }

  1033. 

  1034.             if (!avi->dv_demux &&

  1035.                 ((st->discard >= AVDISCARD_DEFAULT && size == 0) /* ||

  1036.                  // FIXME: needs a little reordering

  1037.                  (st->discard >= AVDISCARD_NONKEY &&

  1038.                  !(pkt->flags & AV_PKT_FLAG_KEY)) */

  1039.                 || st->discard >= AVDISCARD_ALL)) {

  1040.                 if (!exit_early) {

  1041.                     ast->frame_offset += get_duration(ast, size);

  1042.                 }

  1043.                 avio_skip(pb, size);

  1044.                 goto start_sync;

  1045.             }

  1046. 

  1047.             if (d[2] == 'p' && d[3] == 'c' && size <= 4 * 256 + 4) {

  1048.                 int k    = avio_r8(pb);

  1049.                 int last = (k + avio_r8(pb) - 1) & 0xFF;

  1050. 

  1051.                 avio_rl16(pb); // flags

  1052. 

  1053.                 // b + (g << 8) + (r << 16);

  1054.                 for (; k <= last; k++)

  1055.                     ast->pal[k] = avio_rb32(pb) >> 8;

  1056. 

  1057.                 ast->has_pal = 1;

  1058.                 goto start_sync;

  1059.             } else if (((ast->prefix_count < 5 || sync + 9 > i) &&

  1060.                         d[2] < 128 && d[3] < 128) ||

  1061.                        d[2] * 256 + d[3] == ast->prefix /* ||

  1062.                        (d[2] == 'd' && d[3] == 'c') ||

  1063.                        (d[2] == 'w' && d[3] == 'b') */) {

  1064.                 if (exit_early)

  1065.                     return 0;

  1066.                 if (d[2] * 256 + d[3] == ast->prefix)

  1067.                     ast->prefix_count++;

  1068.                 else {

  1069.                     ast->prefix       = d[2] * 256 + d[3];

  1070.                     ast->prefix_count = 0;

  1071.                 }

  1072. 

  1073.                 avi->stream_index = n;

  1074.                 ast->packet_size  = size + 8;

  1075.                 ast->remaining    = size;

  1076. 

  1077.                 if (size || !ast->sample_size) {

  1078.                     uint64_t pos = avio_tell(pb) - 8;

  1079.                     if (!st->index_entries || !st->nb_index_entries ||

  1080.                         st->index_entries[st->nb_index_entries - 1].pos < pos) {

  1081.                         av_add_index_entry(st, pos, ast->frame_offset, size,

  1082.                                            0, AVINDEX_KEYFRAME);

  1083.                     }

  1084.                 }

  1085.                 return 0;

  1086.             }

  1087.         }

  1088.     }

  1089. 

  1090.     return AVERROR_EOF;

  1091. }

  1092. 

  1093. static int ni_prepare_read(AVFormatContext *s)

  1094. {

  1095.     AVIContext *avi = s->priv_data;

  1096.     int best_stream_index = 0;

  1097.     AVStream *best_st     = NULL;

  1098.     AVIStream *best_ast;

  1099.     int64_t best_ts = INT64_MAX;

  1100.     int i;

  1101. 

  1102.     for (i = 0; i < s->nb_streams; i++) {

  1103.         AVStream *st   = s->streams[i];

  1104.         AVIStream *ast = st->priv_data;

  1105.         int64_t ts     = ast->frame_offset;

  1106.         int64_t last_ts;

  1107. 

  1108.         if (!st->nb_index_entries)

  1109.             continue;

  1110. 

  1111.         last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;

  1112.         if (!ast->remaining && ts > last_ts)

  1113.             continue;

  1114. 

  1115.         ts = av_rescale_q(ts, st->time_base,

  1116.                           (AVRational) { FFMAX(1, ast->sample_size),

  1117.                                          AV_TIME_BASE });

  1118. 

  1119.         av_log(s, AV_LOG_TRACE, "%"PRId64" %d/%d %"PRId64"\n", ts,

  1120.                 st->time_base.num, st->time_base.den, ast->frame_offset);

  1121.         if (ts < best_ts) {

  1122.             best_ts           = ts;

  1123.             best_st           = st;

  1124.             best_stream_index = i;

  1125.         }

  1126.     }

  1127.     if (!best_st)

  1128.         return AVERROR_EOF;

  1129. 

  1130.     best_ast = best_st->priv_data;

  1131.     best_ts  = av_rescale_q(best_ts,

  1132.                             (AVRational) { FFMAX(1, best_ast->sample_size),

  1133.                                            AV_TIME_BASE },

  1134.                             best_st->time_base);

  1135.     if (best_ast->remaining) {

  1136.         i = av_index_search_timestamp(best_st,

  1137.                                       best_ts,

  1138.                                       AVSEEK_FLAG_ANY |

  1139.                                       AVSEEK_FLAG_BACKWARD);

  1140.     } else {

  1141.         i = av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);

  1142.         if (i >= 0)

  1143.             best_ast->frame_offset = best_st->index_entries[i].timestamp;

  1144.     }

  1145. 

  1146.     if (i >= 0) {

  1147.         int64_t pos = best_st->index_entries[i].pos;

  1148.         pos += best_ast->packet_size - best_ast->remaining;

  1149.         avio_seek(s->pb, pos + 8, SEEK_SET);

  1150. 

  1151.         assert(best_ast->remaining <= best_ast->packet_size);

  1152. 

  1153.         avi->stream_index = best_stream_index;

  1154.         if (!best_ast->remaining)

  1155.             best_ast->packet_size =

  1156.             best_ast->remaining   = best_st->index_entries[i].size;

  1157.     }

  1158. 

  1159.     return 0;

  1160. }

  1161. 

  1162. static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)

  1163. {

  1164.     AVIContext *avi = s->priv_data;

  1165.     AVIOContext *pb = s->pb;

  1166.     int err;

  1167. 

  1168.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1169.         int size = avpriv_dv_get_packet(avi->dv_demux, pkt);

  1170.         if (size >= 0)

  1171.             return size;

  1172.         else

  1173.             goto resync;

  1174.     }

  1175. 

  1176.     if (avi->non_interleaved) {

  1177.         err = ni_prepare_read(s);

  1178.         if (err < 0)

  1179.             return err;

  1180.     }

  1181. 

  1182. resync:

  1183.     if (avi->stream_index >= 0) {

  1184.         AVStream *st   = s->streams[avi->stream_index];

  1185.         AVIStream *ast = st->priv_data;

  1186.         int size, err;

  1187. 

  1188.         if (get_subtitle_pkt(s, st, pkt))

  1189.             return 0;

  1190. 

  1191.         // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM

  1192.         if (ast->sample_size <= 1)

  1193.             size = INT_MAX;

  1194.         else if (ast->sample_size < 32)

  1195.             // arbitrary multiplier to avoid tiny packets for raw PCM data

  1196.             size = 1024 * ast->sample_size;

  1197.         else

  1198.             size = ast->sample_size;

  1199. 

  1200.         if (size > ast->remaining)

  1201.             size = ast->remaining;

  1202.         avi->last_pkt_pos = avio_tell(pb);

  1203.         err               = av_get_packet(pb, pkt, size);

  1204.         if (err < 0)

  1205.             return err;

  1206. 

  1207.         if (ast->has_pal && pkt->data && pkt->size < (unsigned)INT_MAX / 2) {

  1208.             uint8_t *pal;

  1209.             pal = av_packet_new_side_data(pkt,

  1210.                                           AV_PKT_DATA_PALETTE,

  1211.                                           AVPALETTE_SIZE);

  1212.             if (!pal) {

  1213.                 av_log(s, AV_LOG_ERROR,

  1214.                        "Failed to allocate data for palette\n");

  1215.             } else {

  1216.                 memcpy(pal, ast->pal, AVPALETTE_SIZE);

  1217.                 ast->has_pal = 0;

  1218.             }

  1219.         }

  1220. 

  1221.         if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1222.             AVBufferRef *avbuf = pkt->buf;

  1223.             size = avpriv_dv_produce_packet(avi->dv_demux, pkt,

  1224.                                             pkt->data, pkt->size);

  1225.             pkt->buf    = avbuf;

  1226.             pkt->flags |= AV_PKT_FLAG_KEY;

  1227.             if (size < 0)

  1228.                 av_packet_unref(pkt);

  1229.         } else if (st->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE &&

  1230.                    !st->codecpar->codec_tag && read_gab2_sub(st, pkt)) {

  1231.             ast->frame_offset++;

  1232.             avi->stream_index = -1;

  1233.             ast->remaining    = 0;

  1234.             goto resync;

  1235.         } else {

  1236.             /* XXX: How to handle B-frames in AVI? */

  1237.             pkt->dts = ast->frame_offset;

  1238. //                pkt->dts += ast->start;

  1239.             if (ast->sample_size)

  1240.                 pkt->dts /= ast->sample_size;

  1241.             pkt->stream_index = avi->stream_index;

  1242. 

  1243.             if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {

  1244.                 AVIndexEntry *e;

  1245.                 int index;

  1246.                 assert(st->index_entries);

  1247. 

  1248.                 index = av_index_search_timestamp(st, ast->frame_offset, 0);

  1249.                 e     = &st->index_entries[index];

  1250. 

  1251.                 if (index >= 0 && e->timestamp == ast->frame_offset)

  1252.                     if (e->flags & AVINDEX_KEYFRAME)

  1253.                         pkt->flags |= AV_PKT_FLAG_KEY;

  1254.             } else {

  1255.                 pkt->flags |= AV_PKT_FLAG_KEY;

  1256.             }

  1257.             ast->frame_offset += get_duration(ast, pkt->size);

  1258.         }

  1259.         ast->remaining -= err;

  1260.         if (!ast->remaining) {

  1261.             avi->stream_index = -1;

  1262.             ast->packet_size  = 0;

  1263.         }

  1264. 

  1265.         return 0;

  1266.     }

  1267. 

  1268.     if ((err = avi_sync(s, 0)) < 0)

  1269.         return err;

  1270.     goto resync;

  1271. }

  1272. 

  1273. /* XXX: We make the implicit supposition that the positions are sorted

  1274.  * for each stream. */

  1275. static int avi_read_idx1(AVFormatContext *s, int size)

  1276. {

  1277.     AVIContext *avi = s->priv_data;

  1278.     AVIOContext *pb = s->pb;

  1279.     int nb_index_entries, i;

  1280.     AVStream *st;

  1281.     AVIStream *ast;

  1282.     unsigned int index, tag, flags, pos, len, first_packet = 1;

  1283.     unsigned last_pos = -1;

  1284.     int64_t idx1_pos, first_packet_pos = 0, data_offset = 0;

  1285. 

  1286.     nb_index_entries = size / 16;

  1287.     if (nb_index_entries <= 0)

  1288.         return AVERROR_INVALIDDATA;

  1289. 

  1290.     idx1_pos = avio_tell(pb);

  1291.     avio_seek(pb, avi->movi_list + 4, SEEK_SET);

  1292.     if (avi_sync(s, 1) == 0)

  1293.         first_packet_pos = avio_tell(pb) - 8;

  1294.     avi->stream_index = -1;

  1295.     avio_seek(pb, idx1_pos, SEEK_SET);

  1296. 

  1297.     /* Read the entries and sort them in each stream component. */

  1298.     for (i = 0; i < nb_index_entries; i++) {

  1299.         tag   = avio_rl32(pb);

  1300.         flags = avio_rl32(pb);

  1301.         pos   = avio_rl32(pb);

  1302.         len   = avio_rl32(pb);

  1303.         av_log(s, AV_LOG_TRACE, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",

  1304.                 i, tag, flags, pos, len);

  1305. 

  1306.         index  = ((tag      & 0xff) - '0') * 10;

  1307.         index +=  (tag >> 8 & 0xff) - '0';

  1308.         if (index >= s->nb_streams)

  1309.             continue;

  1310.         st  = s->streams[index];

  1311.         ast = st->priv_data;

  1312. 

  1313.         if (first_packet && first_packet_pos && len) {

  1314.             data_offset  = first_packet_pos - pos;

  1315.             first_packet = 0;

  1316.         }

  1317.         pos += data_offset;

  1318. 

  1319.         av_log(s, AV_LOG_TRACE, "%d cum_len=%"PRId64"\n", len, ast->cum_len);

  1320. 

  1321.         if (pb->eof_reached)

  1322.             return AVERROR_INVALIDDATA;

  1323. 

  1324.         if (last_pos == pos)

  1325.             avi->non_interleaved = 1;

  1326.         else if (len || !ast->sample_size)

  1327.             av_add_index_entry(st, pos, ast->cum_len, len, 0,

  1328.                                (flags & AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);

  1329.         ast->cum_len += get_duration(ast, len);

  1330.         last_pos      = pos;

  1331.     }

  1332.     return 0;

  1333. }

  1334. 

  1335. /* Scan the index and consider any file with streams more than

  1336.  * 2 seconds or 64MB apart non-interleaved. */

  1337. static int check_stream_max_drift(AVFormatContext *s)

  1338. {

  1339.     int64_t min_pos, pos;

  1340.     int i;

  1341.     int *idx = av_mallocz_array(s->nb_streams, sizeof(*idx));

  1342.     if (!idx)

  1343.         return AVERROR(ENOMEM);

  1344. 

  1345.     for (min_pos = pos = 0; min_pos != INT64_MAX; pos = min_pos + 1LU) {

  1346.         int64_t max_dts = INT64_MIN / 2;

  1347.         int64_t min_dts = INT64_MAX / 2;

  1348.         int64_t max_buffer = 0;

  1349. 

  1350.         min_pos = INT64_MAX;

  1351. 

  1352.         for (i = 0; i < s->nb_streams; i++) {

  1353.             AVStream *st = s->streams[i];

  1354.             AVIStream *ast = st->priv_data;

  1355.             int n = st->nb_index_entries;

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

  1357.                 idx[i]++;

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

  1359.                 int64_t dts;

  1360.                 dts = av_rescale_q(st->index_entries[idx[i]].timestamp /

  1361.                                    FFMAX(ast->sample_size, 1),

  1362.                                    st->time_base, AV_TIME_BASE_Q);

  1363.                 min_dts = FFMIN(min_dts, dts);

  1364.                 min_pos = FFMIN(min_pos, st->index_entries[idx[i]].pos);

  1365.             }

  1366.         }

  1367.         for (i = 0; i < s->nb_streams; i++) {

  1368.             AVStream *st = s->streams[i];

  1369.             AVIStream *ast = st->priv_data;

  1370. 

  1371.             if (idx[i] && min_dts != INT64_MAX / 2) {

  1372.                 int64_t dts;

  1373.                 dts = av_rescale_q(st->index_entries[idx[i] - 1].timestamp /

  1374.                                    FFMAX(ast->sample_size, 1),

  1375.                                    st->time_base, AV_TIME_BASE_Q);

  1376.                 max_dts = FFMAX(max_dts, dts);

  1377.                 max_buffer = FFMAX(max_buffer,

  1378.                                    av_rescale(dts - min_dts,

  1379.                                               st->codecpar->bit_rate,

  1380.                                               AV_TIME_BASE));

  1381.             }

  1382.         }

  1383.         if (max_dts - min_dts > 2 * AV_TIME_BASE ||

  1384.             max_buffer > 1024 * 1024 * 8 * 8) {

  1385.             av_free(idx);

  1386.             return 1;

  1387.         }

  1388.     }

  1389.     av_free(idx);

  1390.     return 0;

  1391. }

  1392. 

  1393. static int guess_ni_flag(AVFormatContext *s)

  1394. {

  1395.     int i;

  1396.     int64_t last_start = 0;

  1397.     int64_t first_end  = INT64_MAX;

  1398.     int64_t oldpos     = avio_tell(s->pb);

  1399. 

  1400.     for (i = 0; i < s->nb_streams; i++) {

  1401.         AVStream *st = s->streams[i];

  1402.         int n        = st->nb_index_entries;

  1403.         unsigned int size;

  1404. 

  1405.         if (n <= 0)

  1406.             continue;

  1407. 

  1408.         if (n >= 2) {

  1409.             int64_t pos = st->index_entries[0].pos;

  1410.             avio_seek(s->pb, pos + 4, SEEK_SET);

  1411.             size = avio_rl32(s->pb);

  1412.             if (pos + size > st->index_entries[1].pos)

  1413.                 last_start = INT64_MAX;

  1414.         }

  1415. 

  1416.         if (st->index_entries[0].pos > last_start)

  1417.             last_start = st->index_entries[0].pos;

  1418.         if (st->index_entries[n - 1].pos < first_end)

  1419.             first_end = st->index_entries[n - 1].pos;

  1420.     }

  1421.     avio_seek(s->pb, oldpos, SEEK_SET);

  1422. 

  1423.     if (last_start > first_end)

  1424.         return 1;

  1425. 

  1426.     return check_stream_max_drift(s);

  1427. }

  1428. 

  1429. static int avi_load_index(AVFormatContext *s)

  1430. {

  1431.     AVIContext *avi = s->priv_data;

  1432.     AVIOContext *pb = s->pb;

  1433.     uint32_t tag, size;

  1434.     int64_t pos = avio_tell(pb);

  1435.     int ret     = -1;

  1436. 

  1437.     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)

  1438.         goto the_end; // maybe truncated file

  1439.     av_log(s, AV_LOG_TRACE, "movi_end=0x%"PRIx64"\n", avi->movi_end);

  1440.     for (;;) {

  1441.         if (pb->eof_reached)

  1442.             break;

  1443.         tag  = avio_rl32(pb);

  1444.         size = avio_rl32(pb);

  1445. 

  1446.         if (tag == MKTAG('i', 'd', 'x', '1') &&

  1447.             avi_read_idx1(s, size) >= 0) {

  1448.             ret = 0;

  1449.             break;

  1450.         }

  1451. 

  1452.         size += (size & 1);

  1453.         if (avio_skip(pb, size) < 0)

  1454.             break; // something is wrong here

  1455.     }

  1456. 

  1457. the_end:

  1458.     avio_seek(pb, pos, SEEK_SET);

  1459.     return ret;

  1460. }

  1461. 

  1462. static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)

  1463. {

  1464.     AVIStream *ast2 = st2->priv_data;

  1465.     int64_t ts2     = av_rescale_q(timestamp, st->time_base, st2->time_base);

  1466.     av_packet_unref(&ast2->sub_pkt);

  1467.     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||

  1468.         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)

  1469.         ff_read_packet(ast2->sub_ctx, &ast2->sub_pkt);

  1470. }

  1471. 

  1472. static int avi_read_seek(AVFormatContext *s, int stream_index,

  1473.                          int64_t timestamp, int flags)

  1474. {

  1475.     AVIContext *avi = s->priv_data;

  1476.     AVStream *st;

  1477.     int i, index;

  1478.     int64_t pos;

  1479.     AVIStream *ast;

  1480. 

  1481.     /* Does not matter which stream is requested dv in avi has the

  1482.      * stream information in the first video stream.

  1483.      */

  1484.     if (avi->dv_demux)

  1485.         stream_index = 0;

  1486. 

  1487.     if (!avi->index_loaded) {

  1488.         /* we only load the index on demand */

  1489.         avi_load_index(s);

  1490.         avi->index_loaded = 1;

  1491.     }

  1492. 

  1493.     st    = s->streams[stream_index];

  1494.     ast   = st->priv_data;

  1495.     index = av_index_search_timestamp(st,

  1496.                                       timestamp * FFMAX(ast->sample_size, 1),

  1497.                                       flags);

  1498.     if (index < 0)

  1499.         return AVERROR_INVALIDDATA;

  1500. 

  1501.     /* find the position */

  1502.     pos       = st->index_entries[index].pos;

  1503.     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);

  1504. 

  1505.     av_log(s, AV_LOG_TRACE, "XX %"PRId64" %d %"PRId64"\n",

  1506.             timestamp, index, st->index_entries[index].timestamp);

  1507. 

  1508.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1509.         /* One and only one real stream for DV in AVI, and it has video  */

  1510.         /* offsets. Calling with other stream indexes should have failed */

  1511.         /* the av_index_search_timestamp call above.                     */

  1512. 

  1513.         /* Feed the DV video stream version of the timestamp to the */

  1514.         /* DV demux so it can synthesize correct timestamps.        */

  1515.         ff_dv_offset_reset(avi->dv_demux, timestamp);

  1516. 

  1517.         avio_seek(s->pb, pos, SEEK_SET);

  1518.         avi->stream_index = -1;

  1519.         return 0;

  1520.     }

  1521. 

  1522.     for (i = 0; i < s->nb_streams; i++) {

  1523.         AVStream *st2   = s->streams[i];

  1524.         AVIStream *ast2 = st2->priv_data;

  1525. 

  1526.         ast2->packet_size =

  1527.         ast2->remaining   = 0;

  1528. 

  1529.         if (ast2->sub_ctx) {

  1530.             seek_subtitle(st, st2, timestamp);

  1531.             continue;

  1532.         }

  1533. 

  1534.         if (st2->nb_index_entries <= 0)

  1535.             continue;

  1536. 

  1537. //        assert(st2->codecpar->block_align);

  1538.         assert((int64_t)st2->time_base.num * ast2->rate ==

  1539.                (int64_t)st2->time_base.den * ast2->scale);

  1540.         index = av_index_search_timestamp(st2,

  1541.                                           av_rescale_q(timestamp,

  1542.                                                        st->time_base,

  1543.                                                        st2->time_base) *

  1544.                                           FFMAX(ast2->sample_size, 1),

  1545.                                           flags | AVSEEK_FLAG_BACKWARD);

  1546.         if (index < 0)

  1547.             index = 0;

  1548. 

  1549.         if (!avi->non_interleaved) {

  1550.             while (index > 0 && st2->index_entries[index].pos > pos)

  1551.                 index--;

  1552.             while (index + 1 < st2->nb_index_entries &&

  1553.                    st2->index_entries[index].pos < pos)

  1554.                 index++;

  1555.         }

  1556. 

  1557.         av_log(s, AV_LOG_TRACE, "%"PRId64" %d %"PRId64"\n",

  1558.                 timestamp, index, st2->index_entries[index].timestamp);

  1559.         /* extract the current frame number */

  1560.         ast2->frame_offset = st2->index_entries[index].timestamp;

  1561.     }

  1562. 

  1563.     /* do the seek */

  1564.     avio_seek(s->pb, pos, SEEK_SET);

  1565.     avi->stream_index = -1;

  1566.     return 0;

  1567. }

  1568. 

  1569. static int avi_read_close(AVFormatContext *s)

  1570. {

  1571.     int i;

  1572.     AVIContext *avi = s->priv_data;

  1573. 

  1574.     for (i = 0; i < s->nb_streams; i++) {

  1575.         AVStream *st   = s->streams[i];

  1576.         AVIStream *ast = st->priv_data;

  1577.         if (ast) {

  1578.             if (ast->sub_ctx) {

  1579.                 avio_context_free(&ast->sub_ctx->pb);

  1580.                 avformat_close_input(&ast->sub_ctx);

  1581.             }

  1582.             av_free(ast->sub_buffer);

  1583.             av_packet_unref(&ast->sub_pkt);

  1584.         }

  1585.     }

  1586. 

  1587.     av_free(avi->dv_demux);

  1588. 

  1589.     return 0;

  1590. }

  1591. 

  1592. static int avi_probe(AVProbeData *p)

  1593. {

  1594.     int i;

  1595. 

  1596.     /* check file header */

  1597.     for (i = 0; avi_headers[i][0]; i++)

  1598.         if (!memcmp(p->buf,     avi_headers[i],     4) &&

  1599.             !memcmp(p->buf + 8, avi_headers[i] + 4, 4))

  1600.             return AVPROBE_SCORE_MAX;

  1601. 

  1602.     return 0;

  1603. }

  1604. 

  1605. AVInputFormat ff_avi_demuxer = {

  1606.     .name           = "avi",

  1607.     .long_name      = NULL_IF_CONFIG_SMALL("AVI (Audio Video Interleaved)"),

  1608.     .priv_data_size = sizeof(AVIContext),

  1609.     .extensions     = "avi",

  1610.     .read_probe     = avi_probe,

  1611.     .read_header    = avi_read_header,

  1612.     .read_packet    = avi_read_packet,

  1613.     .read_close     = avi_read_close,

  1614.     .read_seek      = avi_read_seek,

  1615. };