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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 "libavutil/avstring.h"

  23. #include "libavutil/bswap.h"

  24. #include "libavutil/dict.h"

  25. #include "libavutil/internal.h"

  26. #include "libavutil/intreadwrite.h"

  27. #include "libavutil/mathematics.h"

  28. #include "avformat.h"

  29. #include "avi.h"

  30. #include "dv.h"

  31. #include "internal.h"

  32. #include "riff.h"

  33. 

  34. #undef NDEBUG

  35. #include <assert.h>

  36. 

  37. typedef struct AVIStream {

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

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

  40.     int remaining;

  41.     int packet_size;

  42. 

  43.     uint32_t scale;

  44.     uint32_t rate;

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

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

  47. 

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

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

  50.     int prefix_count;

  51.     uint32_t pal[256];

  52.     int has_pal;

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

  54.                              * the MS dshow demuxer */

  55. 

  56.     AVFormatContext *sub_ctx;

  57.     AVPacket sub_pkt;

  58.     uint8_t *sub_buffer;

  59. } AVIStream;

  60. 

  61. typedef struct {

  62.     int64_t riff_end;

  63.     int64_t movi_end;

  64.     int64_t fsize;

  65.     int64_t movi_list;

  66.     int64_t last_pkt_pos;

  67.     int index_loaded;

  68.     int is_odml;

  69.     int non_interleaved;

  70.     int stream_index;

  71.     DVDemuxContext *dv_demux;

  72.     int odml_depth;

  73. #define MAX_ODML_DEPTH 1000

  74. } AVIContext;

  75. 

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

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

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

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

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

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

  82.     { 0 }

  83. };

  84. 

  85. static const AVMetadataConv avi_metadata_conv[] = {

  86.     { "strn", "title" },

  87.     { 0 },

  88. };

  89. 

  90. static int avi_load_index(AVFormatContext *s);

  91. static int guess_ni_flag(AVFormatContext *s);

  92. 

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

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

  95.             str, tag & 0xff,                             \

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

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

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

  99.             size)

  100. 

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

  102. {

  103.     if (ast->sample_size)

  104.         return len;

  105.     else if (ast->dshow_block_align)

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

  107.     else

  108.         return 1;

  109. }

  110. 

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

  112. {

  113.     AVIContext *avi = s->priv_data;

  114.     char header[8];

  115.     int i;

  116. 

  117.     /* check RIFF header */

  118.     avio_read(pb, header, 4);

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

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

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

  122. 

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

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

  125.             break;

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

  127.         return AVERROR_INVALIDDATA;

  128. 

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

  130.         av_log(s, AV_LOG_INFO,

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

  132. 

  133.     return 0;

  134. }

  135. 

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

  137. {

  138.     AVIContext *avi     = s->priv_data;

  139.     AVIOContext *pb     = s->pb;

  140.     int longs_pre_entry = avio_rl16(pb);

  141.     int index_sub_type  = avio_r8(pb);

  142.     int index_type      = avio_r8(pb);

  143.     int entries_in_use  = avio_rl32(pb);

  144.     int chunk_id        = avio_rl32(pb);

  145.     int64_t base        = avio_rl64(pb);

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

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

  148.     AVStream *st;

  149.     AVIStream *ast;

  150.     int i;

  151.     int64_t last_pos = -1;

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

  153. 

  154.     av_dlog(s,

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

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

  157.             longs_pre_entry,

  158.             index_type,

  159.             entries_in_use,

  160.             chunk_id,

  161.             base);

  162. 

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

  164.         return AVERROR_INVALIDDATA;

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

  166.     ast = st->priv_data;

  167. 

  168.     if (index_sub_type)

  169.         return AVERROR_INVALIDDATA;

  170. 

  171.     avio_rl32(pb);

  172. 

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

  174.         return AVERROR_INVALIDDATA;

  175.     if (index_type > 1)

  176.         return AVERROR_INVALIDDATA;

  177. 

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

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

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

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

  182.             filesize <= 0xFFFFFFFF)

  183.             base &= 0xFFFFFFFF;

  184.         else

  185.             return AVERROR_INVALIDDATA;

  186.     }

  187. 

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

  189.         if (index_type) {

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

  191.             int len     = avio_rl32(pb);

  192.             int key     = len >= 0;

  193.             len &= 0x7FFFFFFF;

  194. 

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

  196. 

  197.             if (pb->eof_reached)

  198.                 return AVERROR_INVALIDDATA;

  199. 

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

  201.                 avi->non_interleaved = 1;

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

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

  204.                                    key ? AVINDEX_KEYFRAME : 0);

  205. 

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

  207.             last_pos      = pos;

  208.         } else {

  209.             int64_t offset, pos;

  210.             int duration;

  211.             offset = avio_rl64(pb);

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

  213.             duration = avio_rl32(pb);

  214. 

  215.             if (pb->eof_reached)

  216.                 return AVERROR_INVALIDDATA;

  217. 

  218.             pos = avio_tell(pb);

  219. 

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

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

  222.                 return AVERROR_INVALIDDATA;

  223.             }

  224. 

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

  226.             avi->odml_depth++;

  227.             read_braindead_odml_indx(s, frame_num);

  228.             avi->odml_depth--;

  229.             frame_num += duration;

  230. 

  231.             avio_seek(pb, pos, SEEK_SET);

  232.         }

  233.     }

  234.     avi->index_loaded = 1;

  235.     return 0;

  236. }

  237. 

  238. static void clean_index(AVFormatContext *s)

  239. {

  240.     int i;

  241.     int64_t j;

  242. 

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

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

  245.         AVIStream *ast = st->priv_data;

  246.         int n          = st->nb_index_entries;

  247.         int max        = ast->sample_size;

  248.         int64_t pos, size, ts;

  249. 

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

  251.             continue;

  252. 

  253.         while (max < 1024)

  254.             max += max;

  255. 

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

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

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

  259. 

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

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

  262.                                AVINDEX_KEYFRAME);

  263.     }

  264. }

  265. 

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

  267.                         uint32_t size)

  268. {

  269.     AVIOContext *pb = s->pb;

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

  271.     char *value;

  272. 

  273.     size += (size & 1);

  274. 

  275.     if (size == UINT_MAX)

  276.         return AVERROR(EINVAL);

  277.     value = av_malloc(size + 1);

  278.     if (!value)

  279.         return AVERROR(ENOMEM);

  280.     avio_read(pb, value, size);

  281.     value[size] = 0;

  282. 

  283.     AV_WL32(key, tag);

  284. 

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

  286.                        AV_DICT_DONT_STRDUP_VAL);

  287. }

  288. 

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

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

  291. 

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

  293. {

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

  295.     int i, day, year;

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

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

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

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

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

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

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

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

  304.             }

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

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

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

  308.     }

  309. }

  310. 

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

  312. {

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

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

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

  316.         switch (tag) {

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

  318.         {

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

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

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

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

  323.                 const char *name = NULL;

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

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

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

  327.                 switch (tag) {

  328.                 case 0x03:

  329.                     name = "maker";

  330.                     break;

  331.                 case 0x04:

  332.                     name = "model";

  333.                     break;

  334.                 case 0x13:

  335.                     name = "creation_time";

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

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

  338.                     break;

  339.                 }

  340.                 if (name)

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

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

  343.             }

  344.             break;

  345.         }

  346.         default:

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

  348.             break;

  349.         }

  350.     }

  351. }

  352. 

  353. static int avi_read_header(AVFormatContext *s)

  354. {

  355.     AVIContext *avi = s->priv_data;

  356.     AVIOContext *pb = s->pb;

  357.     unsigned int tag, tag1, handler;

  358.     int codec_type, stream_index, frame_period;

  359.     unsigned int size;

  360.     int i;

  361.     AVStream *st;

  362.     AVIStream *ast      = NULL;

  363.     int avih_width      = 0, avih_height = 0;

  364.     int amv_file_format = 0;

  365.     uint64_t list_end   = 0;

  366.     int ret;

  367. 

  368.     avi->stream_index = -1;

  369. 

  370.     ret = get_riff(s, pb);

  371.     if (ret < 0)

  372.         return ret;

  373. 

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

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

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

  377. 

  378.     /* first list tag */

  379.     stream_index = -1;

  380.     codec_type   = -1;

  381.     frame_period = 0;

  382.     for (;;) {

  383.         if (pb->eof_reached)

  384.             goto fail;

  385.         tag  = avio_rl32(pb);

  386.         size = avio_rl32(pb);

  387. 

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

  389. 

  390.         switch (tag) {

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

  392.             list_end = avio_tell(pb) + size;

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

  394.             tag1 = avio_rl32(pb);

  395. 

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

  397. 

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

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

  400.                 if (size)

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

  402.                 else

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

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

  405.                 goto end_of_header;

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

  407.                 ff_read_riff_info(s, size - 4);

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

  409.                 avi_read_nikon(s, list_end);

  410. 

  411.             break;

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

  413.         {

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

  415.             size += (size & 1);

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

  417.             avio_skip(pb, size);

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

  419.             break;

  420.         }

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

  422.             avi->is_odml = 1;

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

  424.             break;

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

  426.             amv_file_format = 1;

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

  428.             /* AVI header */

  429.             /* using frame_period is bad idea */

  430.             frame_period = avio_rl32(pb);

  431.             avio_skip(pb, 4);

  432.             avio_rl32(pb);

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

  434. 

  435.             avio_skip(pb, 2 * 4);

  436.             avio_rl32(pb);

  437.             avio_rl32(pb);

  438.             avih_width  = avio_rl32(pb);

  439.             avih_height = avio_rl32(pb);

  440. 

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

  442.             break;

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

  444.             /* stream header */

  445. 

  446.             tag1    = avio_rl32(pb);

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

  448. 

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

  450.                 avio_skip(pb, size - 8);

  451.                 break;

  452.             } else {

  453.                 stream_index++;

  454.                 st = avformat_new_stream(s, NULL);

  455.                 if (!st)

  456.                     goto fail;

  457. 

  458.                 st->id = stream_index;

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

  460.                 if (!ast)

  461.                     goto fail;

  462.                 st->priv_data = ast;

  463.             }

  464.             if (amv_file_format)

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

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

  467. 

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

  469. 

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

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

  472.                 int64_t dv_dur;

  473. 

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

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

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

  477.                     goto fail;

  478. 

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

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

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

  482.                     goto fail;

  483. 

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

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

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

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

  488.                 s->nb_streams = 0;

  489.                 if (CONFIG_DV_DEMUXER) {

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

  491.                     if (!avi->dv_demux)

  492.                         goto fail;

  493.                 }

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

  495.                 avio_skip(pb, 3 * 4);

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

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

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

  499. 

  500.                 dv_dur = avio_rl32(pb);

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

  502.                     dv_dur     *= AV_TIME_BASE;

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

  504.                 }

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

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

  507. 

  508.                 stream_index = s->nb_streams - 1;

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

  510.                 break;

  511.             }

  512. 

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

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

  515. 

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

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

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

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

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

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

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

  523.                 av_log(s, AV_LOG_WARNING,

  524.                        "scale/rate is %u/%u which is invalid. "

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

  526.                        ast->scale,

  527.                        ast->rate);

  528.                 if (frame_period) {

  529.                     ast->rate  = 1000000;

  530.                     ast->scale = frame_period;

  531.                 } else {

  532.                     ast->rate  = 25;

  533.                     ast->scale = 1;

  534.                 }

  535.             }

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

  537. 

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

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

  540. 

  541.             st->start_time = 0;

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

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

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

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

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

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

  548. 

  549.             switch (tag1) {

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

  551.                 codec_type = AVMEDIA_TYPE_VIDEO;

  552. 

  553.                 ast->sample_size = 0;

  554.                 break;

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

  556.                 codec_type = AVMEDIA_TYPE_AUDIO;

  557.                 break;

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

  559.                 codec_type = AVMEDIA_TYPE_SUBTITLE;

  560.                 break;

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

  562.                 codec_type = AVMEDIA_TYPE_DATA;

  563.                 break;

  564.             default:

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

  566.                 goto fail;

  567.             }

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

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

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

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

  572.             break;

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

  574.             /* stream header */

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

  576.                 avio_skip(pb, size);

  577.             } else {

  578.                 uint64_t cur_pos = avio_tell(pb);

  579.                 if (cur_pos < list_end)

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

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

  582.                 switch (codec_type) {

  583.                 case AVMEDIA_TYPE_VIDEO:

  584.                     if (amv_file_format) {

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

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

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

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

  589.                         avio_skip(pb, size);

  590.                         break;

  591.                     }

  592.                     tag1 = ff_get_bmp_header(pb, st);

  593. 

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

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

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

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

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

  599.                         break;

  600.                     }

  601. 

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

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

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

  605.                                                               FF_INPUT_BUFFER_PADDING_SIZE);

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

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

  608.                             return AVERROR(ENOMEM);

  609.                         }

  610.                         avio_read(pb,

  611.                                   st->codec->extradata,

  612.                                   st->codec->extradata_size);

  613.                     }

  614. 

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

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

  617.                         avio_r8(pb);

  618. 

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

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

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

  622.                      * Libav. */

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

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

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

  626.                         const uint8_t *pal_src;

  627. 

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

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

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

  631. #if HAVE_BIGENDIAN

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

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

  634. #else

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

  636. #endif

  637.                         ast->has_pal = 1;

  638.                     }

  639. 

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

  641. 

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

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

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

  645.                                                             tag1);

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

  647.                      * for generating correct pts. */

  648.                     st->need_parsing = AVSTREAM_PARSE_HEADERS;

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

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

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

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

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

  654. 

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

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

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

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

  659.                                                st->codec->extradata_size +

  660.                                                FF_INPUT_BUFFER_PADDING_SIZE)) < 0)

  661.                             return ret;

  662.                         else

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

  664.                                    "BottomUp", 9);

  665.                     }

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

  667. 

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

  669.                     break;

  670.                 case AVMEDIA_TYPE_AUDIO:

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

  672.                     if (ret < 0)

  673.                         return ret;

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

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

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

  677.                         av_log(s,

  678.                                AV_LOG_WARNING,

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

  680.                                ast->sample_size,

  681.                                st->codec->block_align);

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

  683.                     }

  684.                     /* 2-aligned

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

  686.                     if (size & 1)

  687.                         avio_skip(pb, 1);

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

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

  690.                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;

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

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

  693.                      * fail. */

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

  695.                         st->codec->extradata_size)

  696.                         st->need_parsing = AVSTREAM_PARSE_NONE;

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

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

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

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

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

  702.                     }

  703.                     if (amv_file_format) {

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

  705.                         ast->dshow_block_align = 0;

  706.                     }

  707.                     break;

  708.                 case AVMEDIA_TYPE_SUBTITLE:

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

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

  711.                     break;

  712.                 default:

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

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

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

  716.                     avio_skip(pb, size);

  717.                     break;

  718.                 }

  719.             }

  720.             break;

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

  722.             i = avio_tell(pb);

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

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

  725.                 (s->error_recognition & AV_EF_EXPLODE))

  726.                 goto fail;

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

  728.             break;

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

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

  731.                 AVRational active, active_aspect;

  732. 

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

  734.                 avio_rl32(pb);

  735.                 avio_rl32(pb);

  736.                 avio_rl32(pb);

  737.                 avio_rl32(pb);

  738.                 avio_rl32(pb);

  739. 

  740.                 active_aspect.den = avio_rl16(pb);

  741.                 active_aspect.num = avio_rl16(pb);

  742.                 active.num        = avio_rl32(pb);

  743.                 active.den        = avio_rl32(pb);

  744.                 avio_rl32(pb); // nbFieldsPerFrame

  745. 

  746.                 if (active_aspect.num && active_aspect.den &&

  747.                     active.num && active.den) {

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

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

  750.                             active_aspect.num, active_aspect.den,

  751.                             active.num, active.den);

  752.                 }

  753.                 size -= 9 * 4;

  754.             }

  755.             avio_skip(pb, size);

  756.             break;

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

  758.             if (s->nb_streams) {

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

  760.                 if (ret < 0)

  761.                     return ret;

  762.                 break;

  763.             }

  764.         default:

  765.             if (size > 1000000) {

  766.                 av_log(s, AV_LOG_ERROR,

  767.                        "Something went wrong during header parsing, "

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

  769.                 if (s->error_recognition & AV_EF_EXPLODE)

  770.                     goto fail;

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

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

  773.                 goto end_of_header;

  774.             }

  775.             /* skip tag */

  776.             size += (size & 1);

  777.             avio_skip(pb, size);

  778.             break;

  779.         }

  780.     }

  781. 

  782. end_of_header:

  783.     /* check stream number */

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

  785. 

  786. fail:

  787.         return AVERROR_INVALIDDATA;

  788.     }

  789. 

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

  791.         avi_load_index(s);

  792.     avi->index_loaded     = 1;

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

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

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

  796.         if (st->nb_index_entries)

  797.             break;

  798.     }

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

  800.         av_log(s, AV_LOG_WARNING,

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

  802.         avi->non_interleaved = 0;

  803.     }

  804. 

  805.     if (avi->non_interleaved) {

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

  807.         clean_index(s);

  808.     }

  809. 

  810.     ff_metadata_conv_ctx(s, NULL, avi_metadata_conv);

  811.     ff_metadata_conv_ctx(s, NULL, ff_riff_info_conv);

  812. 

  813.     return 0;

  814. }

  815. 

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

  817. {

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

  819.         uint8_t desc[256];

  820.         int score      = AVPROBE_SCORE_EXTENSION, ret;

  821.         AVIStream *ast = st->priv_data;

  822.         AVInputFormat *sub_demuxer;

  823.         AVRational time_base;

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

  825.                                              pkt->size - 7,

  826.                                              0, NULL, NULL, NULL, NULL);

  827.         AVProbeData pd;

  828.         unsigned int desc_len = avio_rl32(pb);

  829. 

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

  831.             goto error;

  832. 

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

  834.         avio_skip(pb, desc_len - ret);

  835.         if (*desc)

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

  837. 

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

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

  840. 

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

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

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

  844.             goto error;

  845. 

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

  847.             goto error;

  848. 

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

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

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

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

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

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

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

  856.         }

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

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

  859.         return 1;

  860. 

  861. error:

  862.         av_freep(&pb);

  863.     }

  864.     return 0;

  865. }

  866. 

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

  868.                                   AVPacket *pkt)

  869. {

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

  871.     int64_t ts, next_ts, ts_min = INT64_MAX;

  872.     AVStream *st, *sub_st = NULL;

  873.     int i;

  874. 

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

  876.                            AV_TIME_BASE_Q);

  877. 

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

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

  880.         ast = st->priv_data;

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

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

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

  884.                 ts_min = ts;

  885.                 sub_st = st;

  886.             }

  887.         }

  888.     }

  889. 

  890.     if (sub_st) {

  891.         ast               = sub_st->priv_data;

  892.         *pkt              = ast->sub_pkt;

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

  894. 

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

  896.             ast->sub_pkt.data = NULL;

  897.     }

  898.     return sub_st;

  899. }

  900. 

  901. static int get_stream_idx(int *d)

  902. {

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

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

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

  906.     } else {

  907.         return 100; // invalid stream ID

  908.     }

  909. }

  910. 

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

  912. {

  913.     AVIContext *avi = s->priv_data;

  914.     AVIOContext *pb = s->pb;

  915.     int n;

  916.     unsigned int d[8];

  917.     unsigned int size;

  918.     int64_t i, sync;

  919. 

  920. start_sync:

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

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

  923.         int j;

  924. 

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

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

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

  928. 

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

  930. 

  931.         n = get_stream_idx(d + 2);

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

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

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

  935.             continue;

  936. 

  937.         // parse ix##

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

  939.             // parse JUNK

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

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

  942.             avio_skip(pb, size);

  943.             goto start_sync;

  944.         }

  945. 

  946.         // parse stray LIST

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

  948.             avio_skip(pb, 4);

  949.             goto start_sync;

  950.         }

  951. 

  952.         n = get_stream_idx(d);

  953. 

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

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

  956.             continue;

  957. 

  958.         // detect ##ix chunk and skip

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

  960.             avio_skip(pb, size);

  961.             goto start_sync;

  962.         }

  963. 

  964.         // parse ##dc/##wb

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

  966.             AVStream *st;

  967.             AVIStream *ast;

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

  969.             ast = st->priv_data;

  970. 

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

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

  973.                 AVIStream *ast1 = st1->priv_data;

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

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

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

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

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

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

  980.                      !ast1->prefix_count)) {

  981.                     n   = 1;

  982.                     st  = st1;

  983.                     ast = ast1;

  984.                     av_log(s, AV_LOG_WARNING,

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

  986.                 }

  987.             }

  988. 

  989.             if (!avi->dv_demux &&

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

  991.                  // FIXME: needs a little reordering

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

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

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

  995.                 if (!exit_early) {

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

  997.                 }

  998.                 avio_skip(pb, size);

  999.                 goto start_sync;

  1000.             }

  1001. 

  1002.             if (d[2] == 'p' && d[3] == 'c' && size <= 4 * 256 + 4) {

  1003.                 int k    = avio_r8(pb);

  1004.                 int last = (k + avio_r8(pb) - 1) & 0xFF;

  1005. 

  1006.                 avio_rl16(pb); // flags

  1007. 

  1008.                 // b + (g << 8) + (r << 16);

  1009.                 for (; k <= last; k++)

  1010.                     ast->pal[k] = avio_rb32(pb) >> 8;

  1011. 

  1012.                 ast->has_pal = 1;

  1013.                 goto start_sync;

  1014.             } else if (((ast->prefix_count < 5 || sync + 9 > i) &&

  1015.                         d[2] < 128 && d[3] < 128) ||

  1016.                        d[2] * 256 + d[3] == ast->prefix /* ||

  1017.                        (d[2] == 'd' && d[3] == 'c') ||

  1018.                        (d[2] == 'w' && d[3] == 'b') */) {

  1019.                 if (exit_early)

  1020.                     return 0;

  1021.                 if (d[2] * 256 + d[3] == ast->prefix)

  1022.                     ast->prefix_count++;

  1023.                 else {

  1024.                     ast->prefix       = d[2] * 256 + d[3];

  1025.                     ast->prefix_count = 0;

  1026.                 }

  1027. 

  1028.                 avi->stream_index = n;

  1029.                 ast->packet_size  = size + 8;

  1030.                 ast->remaining    = size;

  1031. 

  1032.                 if (size || !ast->sample_size) {

  1033.                     uint64_t pos = avio_tell(pb) - 8;

  1034.                     if (!st->index_entries || !st->nb_index_entries ||

  1035.                         st->index_entries[st->nb_index_entries - 1].pos < pos) {

  1036.                         av_add_index_entry(st, pos, ast->frame_offset, size,

  1037.                                            0, AVINDEX_KEYFRAME);

  1038.                     }

  1039.                 }

  1040.                 return 0;

  1041.             }

  1042.         }

  1043.     }

  1044. 

  1045.     return AVERROR_EOF;

  1046. }

  1047. 

  1048. static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)

  1049. {

  1050.     AVIContext *avi = s->priv_data;

  1051.     AVIOContext *pb = s->pb;

  1052.     int err;

  1053. #if FF_API_DESTRUCT_PACKET

  1054.     void *dstr;

  1055. #endif

  1056. 

  1057.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1058.         int size = avpriv_dv_get_packet(avi->dv_demux, pkt);

  1059.         if (size >= 0)

  1060.             return size;

  1061.     }

  1062. 

  1063.     if (avi->non_interleaved) {

  1064.         int best_stream_index = 0;

  1065.         AVStream *best_st     = NULL;

  1066.         AVIStream *best_ast;

  1067.         int64_t best_ts = INT64_MAX;

  1068.         int i;

  1069. 

  1070.         for (i = 0; i < s->nb_streams; i++) {

  1071.             AVStream *st   = s->streams[i];

  1072.             AVIStream *ast = st->priv_data;

  1073.             int64_t ts     = ast->frame_offset;

  1074.             int64_t last_ts;

  1075. 

  1076.             if (!st->nb_index_entries)

  1077.                 continue;

  1078. 

  1079.             last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;

  1080.             if (!ast->remaining && ts > last_ts)

  1081.                 continue;

  1082. 

  1083.             ts = av_rescale_q(ts, st->time_base,

  1084.                               (AVRational) { FFMAX(1, ast->sample_size),

  1085.                                              AV_TIME_BASE });

  1086. 

  1087.             av_dlog(s, "%"PRId64" %d/%d %"PRId64"\n", ts,

  1088.                     st->time_base.num, st->time_base.den, ast->frame_offset);

  1089.             if (ts < best_ts) {

  1090.                 best_ts           = ts;

  1091.                 best_st           = st;

  1092.                 best_stream_index = i;

  1093.             }

  1094.         }

  1095.         if (!best_st)

  1096.             return AVERROR_EOF;

  1097. 

  1098.         best_ast = best_st->priv_data;

  1099.         best_ts  = av_rescale_q(best_ts,

  1100.                                 (AVRational) { FFMAX(1, best_ast->sample_size),

  1101.                                                AV_TIME_BASE },

  1102.                                 best_st->time_base);

  1103.         if (best_ast->remaining) {

  1104.             i = av_index_search_timestamp(best_st,

  1105.                                           best_ts,

  1106.                                           AVSEEK_FLAG_ANY |

  1107.                                           AVSEEK_FLAG_BACKWARD);

  1108.         } else {

  1109.             i = av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);

  1110.             if (i >= 0)

  1111.                 best_ast->frame_offset = best_st->index_entries[i].timestamp;

  1112.         }

  1113. 

  1114.         if (i >= 0) {

  1115.             int64_t pos = best_st->index_entries[i].pos;

  1116.             pos += best_ast->packet_size - best_ast->remaining;

  1117.             avio_seek(s->pb, pos + 8, SEEK_SET);

  1118. 

  1119.             assert(best_ast->remaining <= best_ast->packet_size);

  1120. 

  1121.             avi->stream_index = best_stream_index;

  1122.             if (!best_ast->remaining)

  1123.                 best_ast->packet_size =

  1124.                 best_ast->remaining   = best_st->index_entries[i].size;

  1125.         }

  1126.     }

  1127. 

  1128. resync:

  1129.     if (avi->stream_index >= 0) {

  1130.         AVStream *st   = s->streams[avi->stream_index];

  1131.         AVIStream *ast = st->priv_data;

  1132.         int size, err;

  1133. 

  1134.         if (get_subtitle_pkt(s, st, pkt))

  1135.             return 0;

  1136. 

  1137.         // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM

  1138.         if (ast->sample_size <= 1)

  1139.             size = INT_MAX;

  1140.         else if (ast->sample_size < 32)

  1141.             // arbitrary multiplier to avoid tiny packets for raw PCM data

  1142.             size = 1024 * ast->sample_size;

  1143.         else

  1144.             size = ast->sample_size;

  1145. 

  1146.         if (size > ast->remaining)

  1147.             size = ast->remaining;

  1148.         avi->last_pkt_pos = avio_tell(pb);

  1149.         err               = av_get_packet(pb, pkt, size);

  1150.         if (err < 0)

  1151.             return err;

  1152. 

  1153.         if (ast->has_pal && pkt->data && pkt->size < (unsigned)INT_MAX / 2) {

  1154.             uint8_t *pal;

  1155.             pal = av_packet_new_side_data(pkt,

  1156.                                           AV_PKT_DATA_PALETTE,

  1157.                                           AVPALETTE_SIZE);

  1158.             if (!pal) {

  1159.                 av_log(s, AV_LOG_ERROR,

  1160.                        "Failed to allocate data for palette\n");

  1161.             } else {

  1162.                 memcpy(pal, ast->pal, AVPALETTE_SIZE);

  1163.                 ast->has_pal = 0;

  1164.             }

  1165.         }

  1166. 

  1167.         if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1168.             AVBufferRef *avbuf = pkt->buf;

  1169. #if FF_API_DESTRUCT_PACKET

  1170. FF_DISABLE_DEPRECATION_WARNINGS

  1171.             dstr = pkt->destruct;

  1172. FF_ENABLE_DEPRECATION_WARNINGS

  1173. #endif

  1174.             size = avpriv_dv_produce_packet(avi->dv_demux, pkt,

  1175.                                             pkt->data, pkt->size);

  1176. #if FF_API_DESTRUCT_PACKET

  1177. FF_DISABLE_DEPRECATION_WARNINGS

  1178.             pkt->destruct = dstr;

  1179. FF_ENABLE_DEPRECATION_WARNINGS

  1180. #endif

  1181.             pkt->buf    = avbuf;

  1182.             pkt->flags |= AV_PKT_FLAG_KEY;

  1183.             if (size < 0)

  1184.                 av_free_packet(pkt);

  1185.         } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE &&

  1186.                    !st->codec->codec_tag && read_gab2_sub(st, pkt)) {

  1187.             ast->frame_offset++;

  1188.             avi->stream_index = -1;

  1189.             ast->remaining    = 0;

  1190.             goto resync;

  1191.         } else {

  1192.             /* XXX: How to handle B-frames in AVI? */

  1193.             pkt->dts = ast->frame_offset;

  1194. //                pkt->dts += ast->start;

  1195.             if (ast->sample_size)

  1196.                 pkt->dts /= ast->sample_size;

  1197.             av_dlog(s,

  1198.                     "dts:%"PRId64" offset:%"PRId64" %d/%d smpl_siz:%d "

  1199.                     "base:%d st:%d size:%d\n",

  1200.                     pkt->dts,

  1201.                     ast->frame_offset,

  1202.                     ast->scale,

  1203.                     ast->rate,

  1204.                     ast->sample_size,

  1205.                     AV_TIME_BASE,

  1206.                     avi->stream_index,

  1207.                     size);

  1208.             pkt->stream_index = avi->stream_index;

  1209. 

  1210.             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

  1211.                 AVIndexEntry *e;

  1212.                 int index;

  1213.                 assert(st->index_entries);

  1214. 

  1215.                 index = av_index_search_timestamp(st, ast->frame_offset, 0);

  1216.                 e     = &st->index_entries[index];

  1217. 

  1218.                 if (index >= 0 && e->timestamp == ast->frame_offset)

  1219.                     if (e->flags & AVINDEX_KEYFRAME)

  1220.                         pkt->flags |= AV_PKT_FLAG_KEY;

  1221.             } else {

  1222.                 pkt->flags |= AV_PKT_FLAG_KEY;

  1223.             }

  1224.             ast->frame_offset += get_duration(ast, pkt->size);

  1225.         }

  1226.         ast->remaining -= err;

  1227.         if (!ast->remaining) {

  1228.             avi->stream_index = -1;

  1229.             ast->packet_size  = 0;

  1230.         }

  1231. 

  1232.         return 0;

  1233.     }

  1234. 

  1235.     if ((err = avi_sync(s, 0)) < 0)

  1236.         return err;

  1237.     goto resync;

  1238. }

  1239. 

  1240. /* XXX: We make the implicit supposition that the positions are sorted

  1241.  * for each stream. */

  1242. static int avi_read_idx1(AVFormatContext *s, int size)

  1243. {

  1244.     AVIContext *avi = s->priv_data;

  1245.     AVIOContext *pb = s->pb;

  1246.     int nb_index_entries, i;

  1247.     AVStream *st;

  1248.     AVIStream *ast;

  1249.     unsigned int index, tag, flags, pos, len, first_packet = 1;

  1250.     unsigned last_pos = -1;

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

  1252. 

  1253.     nb_index_entries = size / 16;

  1254.     if (nb_index_entries <= 0)

  1255.         return AVERROR_INVALIDDATA;

  1256. 

  1257.     idx1_pos = avio_tell(pb);

  1258.     avio_seek(pb, avi->movi_list + 4, SEEK_SET);

  1259.     if (avi_sync(s, 1) == 0)

  1260.         first_packet_pos = avio_tell(pb) - 8;

  1261.     avi->stream_index = -1;

  1262.     avio_seek(pb, idx1_pos, SEEK_SET);

  1263. 

  1264.     /* Read the entries and sort them in each stream component. */

  1265.     for (i = 0; i < nb_index_entries; i++) {

  1266.         tag   = avio_rl32(pb);

  1267.         flags = avio_rl32(pb);

  1268.         pos   = avio_rl32(pb);

  1269.         len   = avio_rl32(pb);

  1270.         av_dlog(s, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",

  1271.                 i, tag, flags, pos, len);

  1272. 

  1273.         index  = ((tag      & 0xff) - '0') * 10;

  1274.         index +=  (tag >> 8 & 0xff) - '0';

  1275.         if (index >= s->nb_streams)

  1276.             continue;

  1277.         st  = s->streams[index];

  1278.         ast = st->priv_data;

  1279. 

  1280.         if (first_packet && first_packet_pos && len) {

  1281.             data_offset  = first_packet_pos - pos;

  1282.             first_packet = 0;

  1283.         }

  1284.         pos += data_offset;

  1285. 

  1286.         av_dlog(s, "%d cum_len=%"PRId64"\n", len, ast->cum_len);

  1287. 

  1288.         if (pb->eof_reached)

  1289.             return AVERROR_INVALIDDATA;

  1290. 

  1291.         if (last_pos == pos)

  1292.             avi->non_interleaved = 1;

  1293.         else if (len || !ast->sample_size)

  1294.             av_add_index_entry(st, pos, ast->cum_len, len, 0,

  1295.                                (flags & AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);

  1296.         ast->cum_len += get_duration(ast, len);

  1297.         last_pos      = pos;

  1298.     }

  1299.     return 0;

  1300. }

  1301. 

  1302. static int guess_ni_flag(AVFormatContext *s)

  1303. {

  1304.     int i;

  1305.     int64_t last_start = 0;

  1306.     int64_t first_end  = INT64_MAX;

  1307.     int64_t oldpos     = avio_tell(s->pb);

  1308. 

  1309.     for (i = 0; i < s->nb_streams; i++) {

  1310.         AVStream *st = s->streams[i];

  1311.         int n        = st->nb_index_entries;

  1312.         unsigned int size;

  1313. 

  1314.         if (n <= 0)

  1315.             continue;

  1316. 

  1317.         if (n >= 2) {

  1318.             int64_t pos = st->index_entries[0].pos;

  1319.             avio_seek(s->pb, pos + 4, SEEK_SET);

  1320.             size = avio_rl32(s->pb);

  1321.             if (pos + size > st->index_entries[1].pos)

  1322.                 last_start = INT64_MAX;

  1323.         }

  1324. 

  1325.         if (st->index_entries[0].pos > last_start)

  1326.             last_start = st->index_entries[0].pos;

  1327.         if (st->index_entries[n - 1].pos < first_end)

  1328.             first_end = st->index_entries[n - 1].pos;

  1329.     }

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

  1331.     return last_start > first_end;

  1332. }

  1333. 

  1334. static int avi_load_index(AVFormatContext *s)

  1335. {

  1336.     AVIContext *avi = s->priv_data;

  1337.     AVIOContext *pb = s->pb;

  1338.     uint32_t tag, size;

  1339.     int64_t pos = avio_tell(pb);

  1340.     int ret     = -1;

  1341. 

  1342.     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)

  1343.         goto the_end; // maybe truncated file

  1344.     av_dlog(s, "movi_end=0x%"PRIx64"\n", avi->movi_end);

  1345.     for (;;) {

  1346.         if (pb->eof_reached)

  1347.             break;

  1348.         tag  = avio_rl32(pb);

  1349.         size = avio_rl32(pb);

  1350.         av_dlog(s, "tag=%c%c%c%c size=0x%x\n",

  1351.                  tag        & 0xff,

  1352.                 (tag >>  8) & 0xff,

  1353.                 (tag >> 16) & 0xff,

  1354.                 (tag >> 24) & 0xff,

  1355.                 size);

  1356. 

  1357.         if (tag == MKTAG('i', 'd', 'x', '1') &&

  1358.             avi_read_idx1(s, size) >= 0) {

  1359.             ret = 0;

  1360.             break;

  1361.         }

  1362. 

  1363.         size += (size & 1);

  1364.         if (avio_skip(pb, size) < 0)

  1365.             break; // something is wrong here

  1366.     }

  1367. 

  1368. the_end:

  1369.     avio_seek(pb, pos, SEEK_SET);

  1370.     return ret;

  1371. }

  1372. 

  1373. static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)

  1374. {

  1375.     AVIStream *ast2 = st2->priv_data;

  1376.     int64_t ts2     = av_rescale_q(timestamp, st->time_base, st2->time_base);

  1377.     av_free_packet(&ast2->sub_pkt);

  1378.     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||

  1379.         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)

  1380.         ff_read_packet(ast2->sub_ctx, &ast2->sub_pkt);

  1381. }

  1382. 

  1383. static int avi_read_seek(AVFormatContext *s, int stream_index,

  1384.                          int64_t timestamp, int flags)

  1385. {

  1386.     AVIContext *avi = s->priv_data;

  1387.     AVStream *st;

  1388.     int i, index;

  1389.     int64_t pos;

  1390.     AVIStream *ast;

  1391. 

  1392.     if (!avi->index_loaded) {

  1393.         /* we only load the index on demand */

  1394.         avi_load_index(s);

  1395.         avi->index_loaded = 1;

  1396.     }

  1397.     assert(stream_index >= 0);

  1398. 

  1399.     st    = s->streams[stream_index];

  1400.     ast   = st->priv_data;

  1401.     index = av_index_search_timestamp(st,

  1402.                                       timestamp * FFMAX(ast->sample_size, 1),

  1403.                                       flags);

  1404.     if (index < 0)

  1405.         return AVERROR_INVALIDDATA;

  1406. 

  1407.     /* find the position */

  1408.     pos       = st->index_entries[index].pos;

  1409.     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);

  1410. 

  1411.     av_dlog(s, "XX %"PRId64" %d %"PRId64"\n",

  1412.             timestamp, index, st->index_entries[index].timestamp);

  1413. 

  1414.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1415.         /* One and only one real stream for DV in AVI, and it has video  */

  1416.         /* offsets. Calling with other stream indexes should have failed */

  1417.         /* the av_index_search_timestamp call above.                     */

  1418.         assert(stream_index == 0);

  1419. 

  1420.         /* Feed the DV video stream version of the timestamp to the */

  1421.         /* DV demux so it can synthesize correct timestamps.        */

  1422.         ff_dv_offset_reset(avi->dv_demux, timestamp);

  1423. 

  1424.         avio_seek(s->pb, pos, SEEK_SET);

  1425.         avi->stream_index = -1;

  1426.         return 0;

  1427.     }

  1428. 

  1429.     for (i = 0; i < s->nb_streams; i++) {

  1430.         AVStream *st2   = s->streams[i];

  1431.         AVIStream *ast2 = st2->priv_data;

  1432. 

  1433.         ast2->packet_size =

  1434.         ast2->remaining   = 0;

  1435. 

  1436.         if (ast2->sub_ctx) {

  1437.             seek_subtitle(st, st2, timestamp);

  1438.             continue;

  1439.         }

  1440. 

  1441.         if (st2->nb_index_entries <= 0)

  1442.             continue;

  1443. 

  1444. //        assert(st2->codec->block_align);

  1445.         assert((int64_t)st2->time_base.num * ast2->rate ==

  1446.                (int64_t)st2->time_base.den * ast2->scale);

  1447.         index = av_index_search_timestamp(st2,

  1448.                                           av_rescale_q(timestamp,

  1449.                                                        st->time_base,

  1450.                                                        st2->time_base) *

  1451.                                           FFMAX(ast2->sample_size, 1),

  1452.                                           flags | AVSEEK_FLAG_BACKWARD);

  1453.         if (index < 0)

  1454.             index = 0;

  1455. 

  1456.         if (!avi->non_interleaved) {

  1457.             while (index > 0 && st2->index_entries[index].pos > pos)

  1458.                 index--;

  1459.             while (index + 1 < st2->nb_index_entries &&

  1460.                    st2->index_entries[index].pos < pos)

  1461.                 index++;

  1462.         }

  1463. 

  1464.         av_dlog(s, "%"PRId64" %d %"PRId64"\n",

  1465.                 timestamp, index, st2->index_entries[index].timestamp);

  1466.         /* extract the current frame number */

  1467.         ast2->frame_offset = st2->index_entries[index].timestamp;

  1468.     }

  1469. 

  1470.     /* do the seek */

  1471.     avio_seek(s->pb, pos, SEEK_SET);

  1472.     avi->stream_index = -1;

  1473.     return 0;

  1474. }

  1475. 

  1476. static int avi_read_close(AVFormatContext *s)

  1477. {

  1478.     int i;

  1479.     AVIContext *avi = s->priv_data;

  1480. 

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

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

  1483.         AVIStream *ast = st->priv_data;

  1484.         if (ast) {

  1485.             if (ast->sub_ctx) {

  1486.                 av_freep(&ast->sub_ctx->pb);

  1487.                 avformat_close_input(&ast->sub_ctx);

  1488.             }

  1489.             av_free(ast->sub_buffer);

  1490.             av_free_packet(&ast->sub_pkt);

  1491.         }

  1492.     }

  1493. 

  1494.     av_free(avi->dv_demux);

  1495. 

  1496.     return 0;

  1497. }

  1498. 

  1499. static int avi_probe(AVProbeData *p)

  1500. {

  1501.     int i;

  1502. 

  1503.     /* check file header */

  1504.     for (i = 0; avi_headers[i][0]; i++)

  1505.         if (!memcmp(p->buf,     avi_headers[i],     4) &&

  1506.             !memcmp(p->buf + 8, avi_headers[i] + 4, 4))

  1507.             return AVPROBE_SCORE_MAX;

  1508. 

  1509.     return 0;

  1510. }

  1511. 

  1512. AVInputFormat ff_avi_demuxer = {

  1513.     .name           = "avi",

  1514.     .long_name      = NULL_IF_CONFIG_SMALL("AVI (Audio Video Interleaved)"),

  1515.     .priv_data_size = sizeof(AVIContext),

  1516.     .read_probe     = avi_probe,

  1517.     .read_header    = avi_read_header,

  1518.     .read_packet    = avi_read_packet,

  1519.     .read_close     = avi_read_close,

  1520.     .read_seek      = avi_read_seek,

  1521. };