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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 "riff.h"

  35. 

  36. #undef NDEBUG

  37. #include <assert.h>

  38. 

  39. typedef struct AVIStream {

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

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

  42.     int remaining;

  43.     int packet_size;

  44. 

  45.     uint32_t scale;

  46.     uint32_t rate;

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

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

  49. 

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

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

  52.     int prefix_count;

  53.     uint32_t pal[256];

  54.     int has_pal;

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

  56.                              * the MS dshow demuxer */

  57. 

  58.     AVFormatContext *sub_ctx;

  59.     AVPacket sub_pkt;

  60.     uint8_t *sub_buffer;

  61. } AVIStream;

  62. 

  63. typedef struct {

  64.     int64_t riff_end;

  65.     int64_t movi_end;

  66.     int64_t fsize;

  67.     int64_t movi_list;

  68.     int64_t last_pkt_pos;

  69.     int index_loaded;

  70.     int is_odml;

  71.     int non_interleaved;

  72.     int stream_index;

  73.     DVDemuxContext *dv_demux;

  74.     int odml_depth;

  75. #define MAX_ODML_DEPTH 1000

  76. } AVIContext;

  77. 

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

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

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

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

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

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

  84.     { 0 }

  85. };

  86. 

  87. static const AVMetadataConv avi_metadata_conv[] = {

  88.     { "strn", "title" },

  89.     { 0 },

  90. };

  91. 

  92. static int avi_load_index(AVFormatContext *s);

  93. static int guess_ni_flag(AVFormatContext *s);

  94. 

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

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

  97.             str, tag & 0xff,                             \

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

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

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

  101.             size)

  102. 

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

  104. {

  105.     if (ast->sample_size)

  106.         return len;

  107.     else if (ast->dshow_block_align)

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

  109.     else

  110.         return 1;

  111. }

  112. 

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

  114. {

  115.     AVIContext *avi = s->priv_data;

  116.     char header[8];

  117.     int i;

  118. 

  119.     /* check RIFF header */

  120.     avio_read(pb, header, 4);

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

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

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

  124. 

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

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

  127.             break;

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

  129.         return AVERROR_INVALIDDATA;

  130. 

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

  132.         av_log(s, AV_LOG_INFO,

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

  134. 

  135.     return 0;

  136. }

  137. 

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

  139. {

  140.     AVIContext *avi     = s->priv_data;

  141.     AVIOContext *pb     = s->pb;

  142.     int longs_pre_entry = avio_rl16(pb);

  143.     int index_sub_type  = avio_r8(pb);

  144.     int index_type      = avio_r8(pb);

  145.     int entries_in_use  = avio_rl32(pb);

  146.     int chunk_id        = avio_rl32(pb);

  147.     int64_t base        = avio_rl64(pb);

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

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

  150.     AVStream *st;

  151.     AVIStream *ast;

  152.     int i;

  153.     int64_t last_pos = -1;

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

  155. 

  156.     av_dlog(s,

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

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

  159.             longs_pre_entry,

  160.             index_type,

  161.             entries_in_use,

  162.             chunk_id,

  163.             base);

  164. 

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

  166.         return AVERROR_INVALIDDATA;

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

  168.     ast = st->priv_data;

  169. 

  170.     if (index_sub_type)

  171.         return AVERROR_INVALIDDATA;

  172. 

  173.     avio_rl32(pb);

  174. 

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

  176.         return AVERROR_INVALIDDATA;

  177.     if (index_type > 1)

  178.         return AVERROR_INVALIDDATA;

  179. 

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

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

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

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

  184.             filesize <= 0xFFFFFFFF)

  185.             base &= 0xFFFFFFFF;

  186.         else

  187.             return AVERROR_INVALIDDATA;

  188.     }

  189. 

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

  191.         if (index_type) {

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

  193.             int len     = avio_rl32(pb);

  194.             int key     = len >= 0;

  195.             len &= 0x7FFFFFFF;

  196. 

  197.             av_dlog(s, "pos:%"PRId64", len:%X\n", pos, len);

  198. 

  199.             if (pb->eof_reached)

  200.                 return AVERROR_INVALIDDATA;

  201. 

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

  203.                 avi->non_interleaved = 1;

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

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

  206.                                    key ? AVINDEX_KEYFRAME : 0);

  207. 

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

  209.             last_pos      = pos;

  210.         } else {

  211.             int64_t offset, pos;

  212.             int duration;

  213.             offset = avio_rl64(pb);

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

  215.             duration = avio_rl32(pb);

  216. 

  217.             if (pb->eof_reached)

  218.                 return AVERROR_INVALIDDATA;

  219. 

  220.             pos = avio_tell(pb);

  221. 

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

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

  224.                 return AVERROR_INVALIDDATA;

  225.             }

  226. 

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

  228.             avi->odml_depth++;

  229.             read_braindead_odml_indx(s, frame_num);

  230.             avi->odml_depth--;

  231.             frame_num += duration;

  232. 

  233.             avio_seek(pb, pos, SEEK_SET);

  234.         }

  235.     }

  236.     avi->index_loaded = 1;

  237.     return 0;

  238. }

  239. 

  240. static void clean_index(AVFormatContext *s)

  241. {

  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)

  256.             max += max;

  257. 

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

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

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

  261. 

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

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

  264.                                AVINDEX_KEYFRAME);

  265.     }

  266. }

  267. 

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

  269.                         uint32_t size)

  270. {

  271.     AVIOContext *pb = s->pb;

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

  273.     char *value;

  274. 

  275.     size += (size & 1);

  276. 

  277.     if (size == UINT_MAX)

  278.         return AVERROR(EINVAL);

  279.     value = av_malloc(size + 1);

  280.     if (!value)

  281.         return AVERROR(ENOMEM);

  282.     avio_read(pb, value, size);

  283.     value[size] = 0;

  284. 

  285.     AV_WL32(key, tag);

  286. 

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

  288.                        AV_DICT_DONT_STRDUP_VAL);

  289. }

  290. 

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

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

  293. 

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

  295. {

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

  297.     int i, day, year;

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

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

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

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

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

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

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

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

  306.             }

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

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

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

  310.     }

  311. }

  312. 

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

  314. {

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

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

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

  318.         switch (tag) {

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

  320.         {

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

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

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

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

  325.                 const char *name = NULL;

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

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

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

  329.                 switch (tag) {

  330.                 case 0x03:

  331.                     name = "maker";

  332.                     break;

  333.                 case 0x04:

  334.                     name = "model";

  335.                     break;

  336.                 case 0x13:

  337.                     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)

  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.     ret = get_riff(s, pb);

  373.     if (ret < 0)

  374.         return ret;

  375. 

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

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

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

  379. 

  380.     /* first list tag */

  381.     stream_index = -1;

  382.     codec_type   = -1;

  383.     frame_period = 0;

  384.     for (;;) {

  385.         if (pb->eof_reached)

  386.             goto fail;

  387.         tag  = avio_rl32(pb);

  388.         size = avio_rl32(pb);

  389. 

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

  391. 

  392.         switch (tag) {

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

  394.             list_end = avio_tell(pb) + size;

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

  396.             tag1 = avio_rl32(pb);

  397. 

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

  399. 

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

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

  402.                 if (size)

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

  404.                 else

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

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

  407.                 goto end_of_header;

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

  409.                 ff_read_riff_info(s, size - 4);

  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.         {

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

  417.             size += (size & 1);

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

  419.             avio_skip(pb, size);

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

  421.             break;

  422.         }

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

  424.             avi->is_odml = 1;

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

  426.             break;

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

  428.             amv_file_format = 1;

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

  430.             /* AVI header */

  431.             /* using frame_period is bad idea */

  432.             frame_period = avio_rl32(pb);

  433.             avio_skip(pb, 4);

  434.             avio_rl32(pb);

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

  436. 

  437.             avio_skip(pb, 2 * 4);

  438.             avio_rl32(pb);

  439.             avio_rl32(pb);

  440.             avih_width  = avio_rl32(pb);

  441.             avih_height = avio_rl32(pb);

  442. 

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

  444.             break;

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

  446.             /* stream header */

  447. 

  448.             tag1    = avio_rl32(pb);

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

  450. 

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

  452.                 avio_skip(pb, size - 8);

  453.                 break;

  454.             } else {

  455.                 stream_index++;

  456.                 st = avformat_new_stream(s, NULL);

  457.                 if (!st)

  458.                     goto fail;

  459. 

  460.                 st->id = stream_index;

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

  462.                 if (!ast)

  463.                     goto fail;

  464.                 st->priv_data = ast;

  465.             }

  466.             if (amv_file_format)

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

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

  469. 

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

  471. 

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

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

  474.                 int64_t dv_dur;

  475. 

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

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

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

  479.                     goto fail;

  480. 

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

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

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

  484.                     goto fail;

  485. 

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

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

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

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

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

  491.                 s->nb_streams = 0;

  492.                 if (CONFIG_DV_DEMUXER) {

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

  494.                     if (!avi->dv_demux)

  495.                         goto fail;

  496.                 } else

  497.                     goto fail;

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

  499.                 avio_skip(pb, 3 * 4);

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

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

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

  503. 

  504.                 dv_dur = avio_rl32(pb);

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

  506.                     dv_dur     *= AV_TIME_BASE;

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

  508.                 }

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

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

  511. 

  512.                 stream_index = s->nb_streams - 1;

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

  514.                 break;

  515.             }

  516. 

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

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

  519. 

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

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

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

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

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

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

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

  527.                 av_log(s, AV_LOG_WARNING,

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

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

  530.                        ast->scale,

  531.                        ast->rate);

  532.                 if (frame_period) {

  533.                     ast->rate  = 1000000;

  534.                     ast->scale = frame_period;

  535.                 } else {

  536.                     ast->rate  = 25;

  537.                     ast->scale = 1;

  538.                 }

  539.             }

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

  541. 

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

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

  544. 

  545.             st->start_time = 0;

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

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

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

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

  550.             av_dlog(s, "%"PRIu32" %"PRIu32" %d\n",

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

  552. 

  553.             switch (tag1) {

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

  555.                 codec_type = AVMEDIA_TYPE_VIDEO;

  556. 

  557.                 ast->sample_size = 0;

  558.                 break;

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

  560.                 codec_type = AVMEDIA_TYPE_AUDIO;

  561.                 break;

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

  563.                 codec_type = AVMEDIA_TYPE_SUBTITLE;

  564.                 break;

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

  566.                 codec_type = AVMEDIA_TYPE_DATA;

  567.                 break;

  568.             default:

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

  570.                 goto fail;

  571.             }

  572. 

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

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

  575.                     av_log(s, AV_LOG_ERROR,

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

  577.                            ast->sample_size,

  578.                            stream_index);

  579.                     goto fail;

  580.                 }

  581.                 av_log(s, AV_LOG_WARNING,

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

  583.                        "setting it to 0\n",

  584.                        ast->sample_size,

  585.                        stream_index);

  586.                 ast->sample_size = 0;

  587.             }

  588. 

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

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

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

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

  593.             break;

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

  595.             /* stream header */

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

  597.                 avio_skip(pb, size);

  598.             } else {

  599.                 uint64_t cur_pos = avio_tell(pb);

  600.                 if (cur_pos < list_end)

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

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

  603.                 switch (codec_type) {

  604.                 case AVMEDIA_TYPE_VIDEO:

  605.                     if (amv_file_format) {

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

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

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

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

  610.                         avio_skip(pb, size);

  611.                         break;

  612.                     }

  613.                     tag1 = ff_get_bmp_header(pb, st);

  614. 

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

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

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

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

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

  620.                         break;

  621.                     }

  622. 

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

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

  625.                         st->codec->extradata      = av_malloc(st->codec->extradata_size +

  626.                                                               FF_INPUT_BUFFER_PADDING_SIZE);

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

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

  629.                             return AVERROR(ENOMEM);

  630.                         }

  631.                         avio_read(pb,

  632.                                   st->codec->extradata,

  633.                                   st->codec->extradata_size);

  634.                     }

  635. 

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

  637.                     if (st->codec->extradata_size & 1)

  638.                         avio_r8(pb);

  639. 

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

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

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

  643.                      * Libav. */

  644.                     if (st->codec->extradata_size &&

  645.                         (st->codec->bits_per_coded_sample <= 8)) {

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

  647.                         const uint8_t *pal_src;

  648. 

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

  650.                         pal_src  = st->codec->extradata +

  651.                                    st->codec->extradata_size - pal_size;

  652. #if HAVE_BIGENDIAN

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

  654.                             ast->pal[i] = av_bswap32(((uint32_t *)pal_src)[i]);

  655. #else

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

  657. #endif

  658.                         ast->has_pal = 1;

  659.                     }

  660. 

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

  662. 

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

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

  665.                     st->codec->codec_id   = ff_codec_get_id(ff_codec_bmp_tags,

  666.                                                             tag1);

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

  668.                      * for generating correct pts. */

  669.                     st->need_parsing = AVSTREAM_PARSE_HEADERS;

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

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

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

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

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

  675. 

  676.                     if (st->codec->codec_tag == 0 && st->codec->height > 0 &&

  677.                         st->codec->extradata_size < 1U << 30) {

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

  679.                         if ((ret = av_reallocp(&st->codec->extradata,

  680.                                                st->codec->extradata_size +

  681.                                                FF_INPUT_BUFFER_PADDING_SIZE)) < 0) {

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

  683.                             return ret;

  684.                         } else

  685.                             memcpy(st->codec->extradata + st->codec->extradata_size - 9,

  686.                                    "BottomUp", 9);

  687.                     }

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

  689. 

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

  691.                     break;

  692.                 case AVMEDIA_TYPE_AUDIO:

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

  694.                     if (ret < 0)

  695.                         return ret;

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

  697.                     if (ast->sample_size && st->codec->block_align &&

  698.                         ast->sample_size != st->codec->block_align) {

  699.                         av_log(s,

  700.                                AV_LOG_WARNING,

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

  702.                                ast->sample_size,

  703.                                st->codec->block_align);

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

  705.                     }

  706.                     /* 2-aligned

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

  708.                     if (size & 1)

  709.                         avio_skip(pb, 1);

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

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

  712.                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;

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

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

  715.                      * fail. */

  716.                     if (st->codec->codec_id == AV_CODEC_ID_AAC &&

  717.                         st->codec->extradata_size)

  718.                         st->need_parsing = AVSTREAM_PARSE_NONE;

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

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

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

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

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

  724.                     }

  725.                     if (amv_file_format) {

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

  727.                         ast->dshow_block_align = 0;

  728.                     }

  729.                     break;

  730.                 case AVMEDIA_TYPE_SUBTITLE:

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

  732.                     st->codec->codec_id   = AV_CODEC_ID_PROBE;

  733.                     break;

  734.                 default:

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

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

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

  738.                     avio_skip(pb, size);

  739.                     break;

  740.                 }

  741.             }

  742.             break;

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

  744.             i = avio_tell(pb);

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

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

  747.                 (s->error_recognition & AV_EF_EXPLODE))

  748.                 goto fail;

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

  750.             break;

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

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

  753.                 AVRational active, active_aspect;

  754. 

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

  756.                 avio_rl32(pb);

  757.                 avio_rl32(pb);

  758.                 avio_rl32(pb);

  759.                 avio_rl32(pb);

  760.                 avio_rl32(pb);

  761. 

  762.                 active_aspect.den = avio_rl16(pb);

  763.                 active_aspect.num = avio_rl16(pb);

  764.                 active.num        = avio_rl32(pb);

  765.                 active.den        = avio_rl32(pb);

  766.                 avio_rl32(pb); // nbFieldsPerFrame

  767. 

  768.                 if (active_aspect.num && active_aspect.den &&

  769.                     active.num && active.den) {

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

  771.                     av_dlog(s, "vprp %d/%d %d/%d\n",

  772.                             active_aspect.num, active_aspect.den,

  773.                             active.num, active.den);

  774.                 }

  775.                 size -= 9 * 4;

  776.             }

  777.             avio_skip(pb, size);

  778.             break;

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

  780.             if (s->nb_streams) {

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

  782.                 if (ret < 0)

  783.                     return ret;

  784.                 break;

  785.             }

  786.         default:

  787.             if (size > 1000000) {

  788.                 av_log(s, AV_LOG_ERROR,

  789.                        "Something went wrong during header parsing, "

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

  791.                 if (s->error_recognition & AV_EF_EXPLODE)

  792.                     goto fail;

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

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

  795.                 goto end_of_header;

  796.             }

  797.             /* skip tag */

  798.             size += (size & 1);

  799.             avio_skip(pb, size);

  800.             break;

  801.         }

  802.     }

  803. 

  804. end_of_header:

  805.     /* check stream number */

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

  807. 

  808. fail:

  809.         return AVERROR_INVALIDDATA;

  810.     }

  811. 

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

  813.         avi_load_index(s);

  814.     avi->index_loaded     = 1;

  815. 

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

  817.         return ret;

  818. 

  819.     avi->non_interleaved |= ret;

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

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

  822.         if (st->nb_index_entries)

  823.             break;

  824.     }

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

  826.         av_log(s, AV_LOG_WARNING,

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

  828.         avi->non_interleaved = 0;

  829.     }

  830. 

  831.     if (avi->non_interleaved) {

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

  833.         clean_index(s);

  834.     }

  835. 

  836.     ff_metadata_conv_ctx(s, NULL, avi_metadata_conv);

  837.     ff_metadata_conv_ctx(s, NULL, ff_riff_info_conv);

  838. 

  839.     return 0;

  840. }

  841. 

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

  843. {

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

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

  846.         uint8_t desc[256];

  847.         int score      = AVPROBE_SCORE_EXTENSION, ret;

  848.         AVIStream *ast = st->priv_data;

  849.         AVInputFormat *sub_demuxer;

  850.         AVRational time_base;

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

  852.                                              pkt->size - 7,

  853.                                              0, NULL, NULL, NULL, NULL);

  854.         AVProbeData pd;

  855.         unsigned int desc_len = avio_rl32(pb);

  856. 

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

  858.             goto error;

  859. 

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

  861.         avio_skip(pb, desc_len - ret);

  862.         if (*desc)

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

  864. 

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

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

  867. 

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

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

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

  871.             goto error;

  872. 

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

  874.             goto error;

  875. 

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

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

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

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

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

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

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

  883.         }

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

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

  886.         return 1;

  887. 

  888. error:

  889.         av_freep(&pb);

  890.     }

  891.     return 0;

  892. }

  893. 

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

  895.                                   AVPacket *pkt)

  896. {

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

  898.     int64_t ts, next_ts, ts_min = INT64_MAX;

  899.     AVStream *st, *sub_st = NULL;

  900.     int i;

  901. 

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

  903.                            AV_TIME_BASE_Q);

  904. 

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

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

  907.         ast = st->priv_data;

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

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

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

  911.                 ts_min = ts;

  912.                 sub_st = st;

  913.             }

  914.         }

  915.     }

  916. 

  917.     if (sub_st) {

  918.         ast               = sub_st->priv_data;

  919.         *pkt              = ast->sub_pkt;

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

  921. 

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

  923.             ast->sub_pkt.data = NULL;

  924.     }

  925.     return sub_st;

  926. }

  927. 

  928. static int get_stream_idx(int *d)

  929. {

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

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

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

  933.     } else {

  934.         return 100; // invalid stream ID

  935.     }

  936. }

  937. 

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

  939. {

  940.     AVIContext *avi = s->priv_data;

  941.     AVIOContext *pb = s->pb;

  942.     int n;

  943.     unsigned int d[8];

  944.     unsigned int size;

  945.     int64_t i, sync;

  946. 

  947. start_sync:

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

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

  950.         int j;

  951. 

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

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

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

  955. 

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

  957. 

  958.         n = get_stream_idx(d + 2);

  959.         av_dlog(s, "%X %X %X %X %X %X %X %X %"PRId64" %u %d\n",

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

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

  962.             continue;

  963. 

  964.         // parse ix##

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

  966.             // parse JUNK

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

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

  969.             avio_skip(pb, size);

  970.             goto start_sync;

  971.         }

  972. 

  973.         // parse stray LIST

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

  975.             avio_skip(pb, 4);

  976.             goto start_sync;

  977.         }

  978. 

  979.         n = avi->dv_demux ? 0 : get_stream_idx(d);

  980. 

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

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

  983.             continue;

  984. 

  985.         // detect ##ix chunk and skip

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

  987.             avio_skip(pb, size);

  988.             goto start_sync;

  989.         }

  990. 

  991.         // parse ##dc/##wb

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

  993.             AVStream *st;

  994.             AVIStream *ast;

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

  996.             ast = st->priv_data;

  997. 

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

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

  1000.                 AVIStream *ast1 = st1->priv_data;

  1001.                 // workaround for broken small-file-bug402.avi

  1002.                 if (d[2] == 'w' && d[3] == 'b' && n == 0 &&

  1003.                     st->codec->codec_type  == AVMEDIA_TYPE_VIDEO &&

  1004.                     st1->codec->codec_type == AVMEDIA_TYPE_AUDIO &&

  1005.                     ast->prefix == 'd' * 256 + 'c' &&

  1006.                     (d[2] * 256 + d[3] == ast1->prefix ||

  1007.                      !ast1->prefix_count)) {

  1008.                     n   = 1;

  1009.                     st  = st1;

  1010.                     ast = ast1;

  1011.                     av_log(s, AV_LOG_WARNING,

  1012.                            "Invalid stream + prefix combination, assuming audio.\n");

  1013.                 }

  1014.             }

  1015. 

  1016.             if (!avi->dv_demux &&

  1017.                 ((st->discard >= AVDISCARD_DEFAULT && size == 0) /* ||

  1018.                  // FIXME: needs a little reordering

  1019.                  (st->discard >= AVDISCARD_NONKEY &&

  1020.                  !(pkt->flags & AV_PKT_FLAG_KEY)) */

  1021.                 || st->discard >= AVDISCARD_ALL)) {

  1022.                 if (!exit_early) {

  1023.                     ast->frame_offset += get_duration(ast, size);

  1024.                 }

  1025.                 avio_skip(pb, size);

  1026.                 goto start_sync;

  1027.             }

  1028. 

  1029.             if (d[2] == 'p' && d[3] == 'c' && size <= 4 * 256 + 4) {

  1030.                 int k    = avio_r8(pb);

  1031.                 int last = (k + avio_r8(pb) - 1) & 0xFF;

  1032. 

  1033.                 avio_rl16(pb); // flags

  1034. 

  1035.                 // b + (g << 8) + (r << 16);

  1036.                 for (; k <= last; k++)

  1037.                     ast->pal[k] = avio_rb32(pb) >> 8;

  1038. 

  1039.                 ast->has_pal = 1;

  1040.                 goto start_sync;

  1041.             } else if (((ast->prefix_count < 5 || sync + 9 > i) &&

  1042.                         d[2] < 128 && d[3] < 128) ||

  1043.                        d[2] * 256 + d[3] == ast->prefix /* ||

  1044.                        (d[2] == 'd' && d[3] == 'c') ||

  1045.                        (d[2] == 'w' && d[3] == 'b') */) {

  1046.                 if (exit_early)

  1047.                     return 0;

  1048.                 if (d[2] * 256 + d[3] == ast->prefix)

  1049.                     ast->prefix_count++;

  1050.                 else {

  1051.                     ast->prefix       = d[2] * 256 + d[3];

  1052.                     ast->prefix_count = 0;

  1053.                 }

  1054. 

  1055.                 avi->stream_index = n;

  1056.                 ast->packet_size  = size + 8;

  1057.                 ast->remaining    = size;

  1058. 

  1059.                 if (size || !ast->sample_size) {

  1060.                     uint64_t pos = avio_tell(pb) - 8;

  1061.                     if (!st->index_entries || !st->nb_index_entries ||

  1062.                         st->index_entries[st->nb_index_entries - 1].pos < pos) {

  1063.                         av_add_index_entry(st, pos, ast->frame_offset, size,

  1064.                                            0, AVINDEX_KEYFRAME);

  1065.                     }

  1066.                 }

  1067.                 return 0;

  1068.             }

  1069.         }

  1070.     }

  1071. 

  1072.     return AVERROR_EOF;

  1073. }

  1074. 

  1075. static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)

  1076. {

  1077.     AVIContext *avi = s->priv_data;

  1078.     AVIOContext *pb = s->pb;

  1079.     int err;

  1080. #if FF_API_DESTRUCT_PACKET

  1081.     void *dstr;

  1082. #endif

  1083. 

  1084.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1085.         int size = avpriv_dv_get_packet(avi->dv_demux, pkt);

  1086.         if (size >= 0)

  1087.             return size;

  1088.         else

  1089.             goto resync;

  1090.     }

  1091. 

  1092.     if (avi->non_interleaved) {

  1093.         int best_stream_index = 0;

  1094.         AVStream *best_st     = NULL;

  1095.         AVIStream *best_ast;

  1096.         int64_t best_ts = INT64_MAX;

  1097.         int i;

  1098. 

  1099.         for (i = 0; i < s->nb_streams; i++) {

  1100.             AVStream *st   = s->streams[i];

  1101.             AVIStream *ast = st->priv_data;

  1102.             int64_t ts     = ast->frame_offset;

  1103.             int64_t last_ts;

  1104. 

  1105.             if (!st->nb_index_entries)

  1106.                 continue;

  1107. 

  1108.             last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;

  1109.             if (!ast->remaining && ts > last_ts)

  1110.                 continue;

  1111. 

  1112.             ts = av_rescale_q(ts, st->time_base,

  1113.                               (AVRational) { FFMAX(1, ast->sample_size),

  1114.                                              AV_TIME_BASE });

  1115. 

  1116.             av_dlog(s, "%"PRId64" %d/%d %"PRId64"\n", ts,

  1117.                     st->time_base.num, st->time_base.den, ast->frame_offset);

  1118.             if (ts < best_ts) {

  1119.                 best_ts           = ts;

  1120.                 best_st           = st;

  1121.                 best_stream_index = i;

  1122.             }

  1123.         }

  1124.         if (!best_st)

  1125.             return AVERROR_EOF;

  1126. 

  1127.         best_ast = best_st->priv_data;

  1128.         best_ts  = av_rescale_q(best_ts,

  1129.                                 (AVRational) { FFMAX(1, best_ast->sample_size),

  1130.                                                AV_TIME_BASE },

  1131.                                 best_st->time_base);

  1132.         if (best_ast->remaining) {

  1133.             i = av_index_search_timestamp(best_st,

  1134.                                           best_ts,

  1135.                                           AVSEEK_FLAG_ANY |

  1136.                                           AVSEEK_FLAG_BACKWARD);

  1137.         } else {

  1138.             i = av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);

  1139.             if (i >= 0)

  1140.                 best_ast->frame_offset = best_st->index_entries[i].timestamp;

  1141.         }

  1142. 

  1143.         if (i >= 0) {

  1144.             int64_t pos = best_st->index_entries[i].pos;

  1145.             pos += best_ast->packet_size - best_ast->remaining;

  1146.             avio_seek(s->pb, pos + 8, SEEK_SET);

  1147. 

  1148.             assert(best_ast->remaining <= best_ast->packet_size);

  1149. 

  1150.             avi->stream_index = best_stream_index;

  1151.             if (!best_ast->remaining)

  1152.                 best_ast->packet_size =

  1153.                 best_ast->remaining   = best_st->index_entries[i].size;

  1154.         }

  1155.     }

  1156. 

  1157. resync:

  1158.     if (avi->stream_index >= 0) {

  1159.         AVStream *st   = s->streams[avi->stream_index];

  1160.         AVIStream *ast = st->priv_data;

  1161.         int size, err;

  1162. 

  1163.         if (get_subtitle_pkt(s, st, pkt))

  1164.             return 0;

  1165. 

  1166.         // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM

  1167.         if (ast->sample_size <= 1)

  1168.             size = INT_MAX;

  1169.         else if (ast->sample_size < 32)

  1170.             // arbitrary multiplier to avoid tiny packets for raw PCM data

  1171.             size = 1024 * ast->sample_size;

  1172.         else

  1173.             size = ast->sample_size;

  1174. 

  1175.         if (size > ast->remaining)

  1176.             size = ast->remaining;

  1177.         avi->last_pkt_pos = avio_tell(pb);

  1178.         err               = av_get_packet(pb, pkt, size);

  1179.         if (err < 0)

  1180.             return err;

  1181. 

  1182.         if (ast->has_pal && pkt->data && pkt->size < (unsigned)INT_MAX / 2) {

  1183.             uint8_t *pal;

  1184.             pal = av_packet_new_side_data(pkt,

  1185.                                           AV_PKT_DATA_PALETTE,

  1186.                                           AVPALETTE_SIZE);

  1187.             if (!pal) {

  1188.                 av_log(s, AV_LOG_ERROR,

  1189.                        "Failed to allocate data for palette\n");

  1190.             } else {

  1191.                 memcpy(pal, ast->pal, AVPALETTE_SIZE);

  1192.                 ast->has_pal = 0;

  1193.             }

  1194.         }

  1195. 

  1196.         if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1197.             AVBufferRef *avbuf = pkt->buf;

  1198. #if FF_API_DESTRUCT_PACKET

  1199. FF_DISABLE_DEPRECATION_WARNINGS

  1200.             dstr = pkt->destruct;

  1201. FF_ENABLE_DEPRECATION_WARNINGS

  1202. #endif

  1203.             size = avpriv_dv_produce_packet(avi->dv_demux, pkt,

  1204.                                             pkt->data, pkt->size);

  1205. #if FF_API_DESTRUCT_PACKET

  1206. FF_DISABLE_DEPRECATION_WARNINGS

  1207.             pkt->destruct = dstr;

  1208. FF_ENABLE_DEPRECATION_WARNINGS

  1209. #endif

  1210.             pkt->buf    = avbuf;

  1211.             pkt->flags |= AV_PKT_FLAG_KEY;

  1212.             if (size < 0)

  1213.                 av_free_packet(pkt);

  1214.         } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE &&

  1215.                    !st->codec->codec_tag && read_gab2_sub(st, pkt)) {

  1216.             ast->frame_offset++;

  1217.             avi->stream_index = -1;

  1218.             ast->remaining    = 0;

  1219.             goto resync;

  1220.         } else {

  1221.             /* XXX: How to handle B-frames in AVI? */

  1222.             pkt->dts = ast->frame_offset;

  1223. //                pkt->dts += ast->start;

  1224.             if (ast->sample_size)

  1225.                 pkt->dts /= ast->sample_size;

  1226.             av_dlog(s,

  1227.                     "dts:%"PRId64" offset:%"PRId64" %d/%d smpl_siz:%d "

  1228.                     "base:%d st:%d size:%d\n",

  1229.                     pkt->dts,

  1230.                     ast->frame_offset,

  1231.                     ast->scale,

  1232.                     ast->rate,

  1233.                     ast->sample_size,

  1234.                     AV_TIME_BASE,

  1235.                     avi->stream_index,

  1236.                     size);

  1237.             pkt->stream_index = avi->stream_index;

  1238. 

  1239.             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

  1240.                 AVIndexEntry *e;

  1241.                 int index;

  1242.                 assert(st->index_entries);

  1243. 

  1244.                 index = av_index_search_timestamp(st, ast->frame_offset, 0);

  1245.                 e     = &st->index_entries[index];

  1246. 

  1247.                 if (index >= 0 && e->timestamp == ast->frame_offset)

  1248.                     if (e->flags & AVINDEX_KEYFRAME)

  1249.                         pkt->flags |= AV_PKT_FLAG_KEY;

  1250.             } else {

  1251.                 pkt->flags |= AV_PKT_FLAG_KEY;

  1252.             }

  1253.             ast->frame_offset += get_duration(ast, pkt->size);

  1254.         }

  1255.         ast->remaining -= err;

  1256.         if (!ast->remaining) {

  1257.             avi->stream_index = -1;

  1258.             ast->packet_size  = 0;

  1259.         }

  1260. 

  1261.         return 0;

  1262.     }

  1263. 

  1264.     if ((err = avi_sync(s, 0)) < 0)

  1265.         return err;

  1266.     goto resync;

  1267. }

  1268. 

  1269. /* XXX: We make the implicit supposition that the positions are sorted

  1270.  * for each stream. */

  1271. static int avi_read_idx1(AVFormatContext *s, int size)

  1272. {

  1273.     AVIContext *avi = s->priv_data;

  1274.     AVIOContext *pb = s->pb;

  1275.     int nb_index_entries, i;

  1276.     AVStream *st;

  1277.     AVIStream *ast;

  1278.     unsigned int index, tag, flags, pos, len, first_packet = 1;

  1279.     unsigned last_pos = -1;

  1280.     int64_t idx1_pos, first_packet_pos = 0, data_offset = 0;

  1281. 

  1282.     nb_index_entries = size / 16;

  1283.     if (nb_index_entries <= 0)

  1284.         return AVERROR_INVALIDDATA;

  1285. 

  1286.     idx1_pos = avio_tell(pb);

  1287.     avio_seek(pb, avi->movi_list + 4, SEEK_SET);

  1288.     if (avi_sync(s, 1) == 0)

  1289.         first_packet_pos = avio_tell(pb) - 8;

  1290.     avi->stream_index = -1;

  1291.     avio_seek(pb, idx1_pos, SEEK_SET);

  1292. 

  1293.     /* Read the entries and sort them in each stream component. */

  1294.     for (i = 0; i < nb_index_entries; i++) {

  1295.         tag   = avio_rl32(pb);

  1296.         flags = avio_rl32(pb);

  1297.         pos   = avio_rl32(pb);

  1298.         len   = avio_rl32(pb);

  1299.         av_dlog(s, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",

  1300.                 i, tag, flags, pos, len);

  1301. 

  1302.         index  = ((tag      & 0xff) - '0') * 10;

  1303.         index +=  (tag >> 8 & 0xff) - '0';

  1304.         if (index >= s->nb_streams)

  1305.             continue;

  1306.         st  = s->streams[index];

  1307.         ast = st->priv_data;

  1308. 

  1309.         if (first_packet && first_packet_pos && len) {

  1310.             data_offset  = first_packet_pos - pos;

  1311.             first_packet = 0;

  1312.         }

  1313.         pos += data_offset;

  1314. 

  1315.         av_dlog(s, "%d cum_len=%"PRId64"\n", len, ast->cum_len);

  1316. 

  1317.         if (pb->eof_reached)

  1318.             return AVERROR_INVALIDDATA;

  1319. 

  1320.         if (last_pos == pos)

  1321.             avi->non_interleaved = 1;

  1322.         else if (len || !ast->sample_size)

  1323.             av_add_index_entry(st, pos, ast->cum_len, len, 0,

  1324.                                (flags & AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);

  1325.         ast->cum_len += get_duration(ast, len);

  1326.         last_pos      = pos;

  1327.     }

  1328.     return 0;

  1329. }

  1330. 

  1331. /* Scan the index and consider any file with streams more than

  1332.  * 2 seconds or 64MB apart non-interleaved. */

  1333. static int check_stream_max_drift(AVFormatContext *s)

  1334. {

  1335.     int64_t min_pos, pos;

  1336.     int i;

  1337.     int *idx = av_mallocz_array(s->nb_streams, sizeof(*idx));

  1338.     if (!idx)

  1339.         return AVERROR(ENOMEM);

  1340. 

  1341.     for (min_pos = pos = 0; min_pos != INT64_MAX; pos = min_pos + 1LU) {

  1342.         int64_t max_dts = INT64_MIN / 2;

  1343.         int64_t min_dts = INT64_MAX / 2;

  1344.         int64_t max_buffer = 0;

  1345. 

  1346.         min_pos = INT64_MAX;

  1347. 

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

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

  1350.             AVIStream *ast = st->priv_data;

  1351.             int n = st->nb_index_entries;

  1352.             while (idx[i] < n && st->index_entries[idx[i]].pos < pos)

  1353.                 idx[i]++;

  1354.             if (idx[i] < n) {

  1355.                 int64_t dts;

  1356.                 dts = av_rescale_q(st->index_entries[idx[i]].timestamp /

  1357.                                    FFMAX(ast->sample_size, 1),

  1358.                                    st->time_base, AV_TIME_BASE_Q);

  1359.                 min_dts = FFMIN(min_dts, dts);

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

  1361.             }

  1362.         }

  1363.         for (i = 0; i < s->nb_streams; i++) {

  1364.             AVStream *st = s->streams[i];

  1365.             AVIStream *ast = st->priv_data;

  1366. 

  1367.             if (idx[i] && min_dts != INT64_MAX / 2) {

  1368.                 int64_t dts;

  1369.                 dts = av_rescale_q(st->index_entries[idx[i] - 1].timestamp /

  1370.                                    FFMAX(ast->sample_size, 1),

  1371.                                    st->time_base, AV_TIME_BASE_Q);

  1372.                 max_dts = FFMAX(max_dts, dts);

  1373.                 max_buffer = FFMAX(max_buffer,

  1374.                                    av_rescale(dts - min_dts,

  1375.                                               st->codec->bit_rate,

  1376.                                               AV_TIME_BASE));

  1377.             }

  1378.         }

  1379.         if (max_dts - min_dts > 2 * AV_TIME_BASE ||

  1380.             max_buffer > 1024 * 1024 * 8 * 8) {

  1381.             av_free(idx);

  1382.             return 1;

  1383.         }

  1384.     }

  1385.     av_free(idx);

  1386.     return 0;

  1387. }

  1388. 

  1389. static int guess_ni_flag(AVFormatContext *s)

  1390. {

  1391.     int i;

  1392.     int64_t last_start = 0;

  1393.     int64_t first_end  = INT64_MAX;

  1394.     int64_t oldpos     = avio_tell(s->pb);

  1395. 

  1396.     for (i = 0; i < s->nb_streams; i++) {

  1397.         AVStream *st = s->streams[i];

  1398.         int n        = st->nb_index_entries;

  1399.         unsigned int size;

  1400. 

  1401.         if (n <= 0)

  1402.             continue;

  1403. 

  1404.         if (n >= 2) {

  1405.             int64_t pos = st->index_entries[0].pos;

  1406.             avio_seek(s->pb, pos + 4, SEEK_SET);

  1407.             size = avio_rl32(s->pb);

  1408.             if (pos + size > st->index_entries[1].pos)

  1409.                 last_start = INT64_MAX;

  1410.         }

  1411. 

  1412.         if (st->index_entries[0].pos > last_start)

  1413.             last_start = st->index_entries[0].pos;

  1414.         if (st->index_entries[n - 1].pos < first_end)

  1415.             first_end = st->index_entries[n - 1].pos;

  1416.     }

  1417.     avio_seek(s->pb, oldpos, SEEK_SET);

  1418. 

  1419.     if (last_start > first_end)

  1420.         return 1;

  1421. 

  1422.     return check_stream_max_drift(s);

  1423. }

  1424. 

  1425. static int avi_load_index(AVFormatContext *s)

  1426. {

  1427.     AVIContext *avi = s->priv_data;

  1428.     AVIOContext *pb = s->pb;

  1429.     uint32_t tag, size;

  1430.     int64_t pos = avio_tell(pb);

  1431.     int ret     = -1;

  1432. 

  1433.     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)

  1434.         goto the_end; // maybe truncated file

  1435.     av_dlog(s, "movi_end=0x%"PRIx64"\n", avi->movi_end);

  1436.     for (;;) {

  1437.         if (pb->eof_reached)

  1438.             break;

  1439.         tag  = avio_rl32(pb);

  1440.         size = avio_rl32(pb);

  1441.         av_dlog(s, "tag=%c%c%c%c size=0x%x\n",

  1442.                  tag        & 0xff,

  1443.                 (tag >>  8) & 0xff,

  1444.                 (tag >> 16) & 0xff,

  1445.                 (tag >> 24) & 0xff,

  1446.                 size);

  1447. 

  1448.         if (tag == MKTAG('i', 'd', 'x', '1') &&

  1449.             avi_read_idx1(s, size) >= 0) {

  1450.             ret = 0;

  1451.             break;

  1452.         }

  1453. 

  1454.         size += (size & 1);

  1455.         if (avio_skip(pb, size) < 0)

  1456.             break; // something is wrong here

  1457.     }

  1458. 

  1459. the_end:

  1460.     avio_seek(pb, pos, SEEK_SET);

  1461.     return ret;

  1462. }

  1463. 

  1464. static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)

  1465. {

  1466.     AVIStream *ast2 = st2->priv_data;

  1467.     int64_t ts2     = av_rescale_q(timestamp, st->time_base, st2->time_base);

  1468.     av_free_packet(&ast2->sub_pkt);

  1469.     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||

  1470.         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)

  1471.         ff_read_packet(ast2->sub_ctx, &ast2->sub_pkt);

  1472. }

  1473. 

  1474. static int avi_read_seek(AVFormatContext *s, int stream_index,

  1475.                          int64_t timestamp, int flags)

  1476. {

  1477.     AVIContext *avi = s->priv_data;

  1478.     AVStream *st;

  1479.     int i, index;

  1480.     int64_t pos;

  1481.     AVIStream *ast;

  1482. 

  1483.     /* Does not matter which stream is requested dv in avi has the

  1484.      * stream information in the first video stream.

  1485.      */

  1486.     if (avi->dv_demux)

  1487.         stream_index = 0;

  1488. 

  1489.     if (!avi->index_loaded) {

  1490.         /* we only load the index on demand */

  1491.         avi_load_index(s);

  1492.         avi->index_loaded = 1;

  1493.     }

  1494. 

  1495.     st    = s->streams[stream_index];

  1496.     ast   = st->priv_data;

  1497.     index = av_index_search_timestamp(st,

  1498.                                       timestamp * FFMAX(ast->sample_size, 1),

  1499.                                       flags);

  1500.     if (index < 0)

  1501.         return AVERROR_INVALIDDATA;

  1502. 

  1503.     /* find the position */

  1504.     pos       = st->index_entries[index].pos;

  1505.     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);

  1506. 

  1507.     av_dlog(s, "XX %"PRId64" %d %"PRId64"\n",

  1508.             timestamp, index, st->index_entries[index].timestamp);

  1509. 

  1510.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1511.         /* One and only one real stream for DV in AVI, and it has video  */

  1512.         /* offsets. Calling with other stream indexes should have failed */

  1513.         /* the av_index_search_timestamp call above.                     */

  1514. 

  1515.         /* Feed the DV video stream version of the timestamp to the */

  1516.         /* DV demux so it can synthesize correct timestamps.        */

  1517.         ff_dv_offset_reset(avi->dv_demux, timestamp);

  1518. 

  1519.         avio_seek(s->pb, pos, SEEK_SET);

  1520.         avi->stream_index = -1;

  1521.         return 0;

  1522.     }

  1523. 

  1524.     for (i = 0; i < s->nb_streams; i++) {

  1525.         AVStream *st2   = s->streams[i];

  1526.         AVIStream *ast2 = st2->priv_data;

  1527. 

  1528.         ast2->packet_size =

  1529.         ast2->remaining   = 0;

  1530. 

  1531.         if (ast2->sub_ctx) {

  1532.             seek_subtitle(st, st2, timestamp);

  1533.             continue;

  1534.         }

  1535. 

  1536.         if (st2->nb_index_entries <= 0)

  1537.             continue;

  1538. 

  1539. //        assert(st2->codec->block_align);

  1540.         assert((int64_t)st2->time_base.num * ast2->rate ==

  1541.                (int64_t)st2->time_base.den * ast2->scale);

  1542.         index = av_index_search_timestamp(st2,

  1543.                                           av_rescale_q(timestamp,

  1544.                                                        st->time_base,

  1545.                                                        st2->time_base) *

  1546.                                           FFMAX(ast2->sample_size, 1),

  1547.                                           flags | AVSEEK_FLAG_BACKWARD);

  1548.         if (index < 0)

  1549.             index = 0;

  1550. 

  1551.         if (!avi->non_interleaved) {

  1552.             while (index > 0 && st2->index_entries[index].pos > pos)

  1553.                 index--;

  1554.             while (index + 1 < st2->nb_index_entries &&

  1555.                    st2->index_entries[index].pos < pos)

  1556.                 index++;

  1557.         }

  1558. 

  1559.         av_dlog(s, "%"PRId64" %d %"PRId64"\n",

  1560.                 timestamp, index, st2->index_entries[index].timestamp);

  1561.         /* extract the current frame number */

  1562.         ast2->frame_offset = st2->index_entries[index].timestamp;

  1563.     }

  1564. 

  1565.     /* do the seek */

  1566.     avio_seek(s->pb, pos, SEEK_SET);

  1567.     avi->stream_index = -1;

  1568.     return 0;

  1569. }

  1570. 

  1571. static int avi_read_close(AVFormatContext *s)

  1572. {

  1573.     int i;

  1574.     AVIContext *avi = s->priv_data;

  1575. 

  1576.     for (i = 0; i < s->nb_streams; i++) {

  1577.         AVStream *st   = s->streams[i];

  1578.         AVIStream *ast = st->priv_data;

  1579.         if (ast) {

  1580.             if (ast->sub_ctx) {

  1581.                 av_freep(&ast->sub_ctx->pb);

  1582.                 avformat_close_input(&ast->sub_ctx);

  1583.             }

  1584.             av_free(ast->sub_buffer);

  1585.             av_free_packet(&ast->sub_pkt);

  1586.         }

  1587.     }

  1588. 

  1589.     av_free(avi->dv_demux);

  1590. 

  1591.     return 0;

  1592. }

  1593. 

  1594. static int avi_probe(AVProbeData *p)

  1595. {

  1596.     int i;

  1597. 

  1598.     /* check file header */

  1599.     for (i = 0; avi_headers[i][0]; i++)

  1600.         if (!memcmp(p->buf,     avi_headers[i],     4) &&

  1601.             !memcmp(p->buf + 8, avi_headers[i] + 4, 4))

  1602.             return AVPROBE_SCORE_MAX;

  1603. 

  1604.     return 0;

  1605. }

  1606. 

  1607. AVInputFormat ff_avi_demuxer = {

  1608.     .name           = "avi",

  1609.     .long_name      = NULL_IF_CONFIG_SMALL("AVI (Audio Video Interleaved)"),

  1610.     .priv_data_size = sizeof(AVIContext),

  1611.     .extensions     = "avi",

  1612.     .read_probe     = avi_probe,

  1613.     .read_header    = avi_read_header,

  1614.     .read_packet    = avi_read_packet,

  1615.     .read_close     = avi_read_close,

  1616.     .read_seek      = avi_read_seek,

  1617. };