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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.             if (ast->sample_size == 0)

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

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

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

  576.             break;

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

  578.             /* stream header */

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

  580.                 avio_skip(pb, size);

  581.             } else {

  582.                 uint64_t cur_pos = avio_tell(pb);

  583.                 if (cur_pos < list_end)

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

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

  586.                 switch (codec_type) {

  587.                 case AVMEDIA_TYPE_VIDEO:

  588.                     if (amv_file_format) {

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

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

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

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

  593.                         avio_skip(pb, size);

  594.                         break;

  595.                     }

  596.                     tag1 = ff_get_bmp_header(pb, st);

  597. 

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

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

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

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

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

  603.                         break;

  604.                     }

  605. 

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

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

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

  609.                                                               FF_INPUT_BUFFER_PADDING_SIZE);

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

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

  612.                             return AVERROR(ENOMEM);

  613.                         }

  614.                         avio_read(pb,

  615.                                   st->codec->extradata,

  616.                                   st->codec->extradata_size);

  617.                     }

  618. 

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

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

  621.                         avio_r8(pb);

  622. 

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

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

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

  626.                      * Libav. */

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

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

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

  630.                         const uint8_t *pal_src;

  631. 

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

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

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

  635. #if HAVE_BIGENDIAN

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

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

  638. #else

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

  640. #endif

  641.                         ast->has_pal = 1;

  642.                     }

  643. 

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

  645. 

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

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

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

  649.                                                             tag1);

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

  651.                      * for generating correct pts. */

  652.                     st->need_parsing = AVSTREAM_PARSE_HEADERS;

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

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

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

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

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

  658. 

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

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

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

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

  663.                                                st->codec->extradata_size +

  664.                                                FF_INPUT_BUFFER_PADDING_SIZE)) < 0) {

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

  666.                             return ret;

  667.                         } else

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

  669.                                    "BottomUp", 9);

  670.                     }

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

  672. 

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

  674.                     break;

  675.                 case AVMEDIA_TYPE_AUDIO:

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

  677.                     if (ret < 0)

  678.                         return ret;

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

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

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

  682.                         av_log(s,

  683.                                AV_LOG_WARNING,

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

  685.                                ast->sample_size,

  686.                                st->codec->block_align);

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

  688.                     }

  689.                     /* 2-aligned

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

  691.                     if (size & 1)

  692.                         avio_skip(pb, 1);

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

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

  695.                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;

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

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

  698.                      * fail. */

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

  700.                         st->codec->extradata_size)

  701.                         st->need_parsing = AVSTREAM_PARSE_NONE;

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

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

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

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

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

  707.                     }

  708.                     if (amv_file_format) {

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

  710.                         ast->dshow_block_align = 0;

  711.                     }

  712.                     break;

  713.                 case AVMEDIA_TYPE_SUBTITLE:

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

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

  716.                     break;

  717.                 default:

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

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

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

  721.                     avio_skip(pb, size);

  722.                     break;

  723.                 }

  724.             }

  725.             break;

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

  727.             i = avio_tell(pb);

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

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

  730.                 (s->error_recognition & AV_EF_EXPLODE))

  731.                 goto fail;

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

  733.             break;

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

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

  736.                 AVRational active, active_aspect;

  737. 

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

  739.                 avio_rl32(pb);

  740.                 avio_rl32(pb);

  741.                 avio_rl32(pb);

  742.                 avio_rl32(pb);

  743.                 avio_rl32(pb);

  744. 

  745.                 active_aspect.den = avio_rl16(pb);

  746.                 active_aspect.num = avio_rl16(pb);

  747.                 active.num        = avio_rl32(pb);

  748.                 active.den        = avio_rl32(pb);

  749.                 avio_rl32(pb); // nbFieldsPerFrame

  750. 

  751.                 if (active_aspect.num && active_aspect.den &&

  752.                     active.num && active.den) {

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

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

  755.                             active_aspect.num, active_aspect.den,

  756.                             active.num, active.den);

  757.                 }

  758.                 size -= 9 * 4;

  759.             }

  760.             avio_skip(pb, size);

  761.             break;

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

  763.             if (s->nb_streams) {

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

  765.                 if (ret < 0)

  766.                     return ret;

  767.                 break;

  768.             }

  769.         default:

  770.             if (size > 1000000) {

  771.                 av_log(s, AV_LOG_ERROR,

  772.                        "Something went wrong during header parsing, "

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

  774.                 if (s->error_recognition & AV_EF_EXPLODE)

  775.                     goto fail;

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

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

  778.                 goto end_of_header;

  779.             }

  780.             /* skip tag */

  781.             size += (size & 1);

  782.             avio_skip(pb, size);

  783.             break;

  784.         }

  785.     }

  786. 

  787. end_of_header:

  788.     /* check stream number */

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

  790. 

  791. fail:

  792.         return AVERROR_INVALIDDATA;

  793.     }

  794. 

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

  796.         avi_load_index(s);

  797.     avi->index_loaded     = 1;

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

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

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

  801.         if (st->nb_index_entries)

  802.             break;

  803.     }

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

  805.         av_log(s, AV_LOG_WARNING,

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

  807.         avi->non_interleaved = 0;

  808.     }

  809. 

  810.     if (avi->non_interleaved) {

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

  812.         clean_index(s);

  813.     }

  814. 

  815.     ff_metadata_conv_ctx(s, NULL, avi_metadata_conv);

  816.     ff_metadata_conv_ctx(s, NULL, ff_riff_info_conv);

  817. 

  818.     return 0;

  819. }

  820. 

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

  822. {

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

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

  825.         uint8_t desc[256];

  826.         int score      = AVPROBE_SCORE_EXTENSION, ret;

  827.         AVIStream *ast = st->priv_data;

  828.         AVInputFormat *sub_demuxer;

  829.         AVRational time_base;

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

  831.                                              pkt->size - 7,

  832.                                              0, NULL, NULL, NULL, NULL);

  833.         AVProbeData pd;

  834.         unsigned int desc_len = avio_rl32(pb);

  835. 

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

  837.             goto error;

  838. 

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

  840.         avio_skip(pb, desc_len - ret);

  841.         if (*desc)

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

  843. 

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

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

  846. 

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

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

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

  850.             goto error;

  851. 

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

  853.             goto error;

  854. 

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

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

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

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

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

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

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

  862.         }

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

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

  865.         return 1;

  866. 

  867. error:

  868.         av_freep(&pb);

  869.     }

  870.     return 0;

  871. }

  872. 

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

  874.                                   AVPacket *pkt)

  875. {

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

  877.     int64_t ts, next_ts, ts_min = INT64_MAX;

  878.     AVStream *st, *sub_st = NULL;

  879.     int i;

  880. 

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

  882.                            AV_TIME_BASE_Q);

  883. 

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

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

  886.         ast = st->priv_data;

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

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

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

  890.                 ts_min = ts;

  891.                 sub_st = st;

  892.             }

  893.         }

  894.     }

  895. 

  896.     if (sub_st) {

  897.         ast               = sub_st->priv_data;

  898.         *pkt              = ast->sub_pkt;

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

  900. 

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

  902.             ast->sub_pkt.data = NULL;

  903.     }

  904.     return sub_st;

  905. }

  906. 

  907. static int get_stream_idx(int *d)

  908. {

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

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

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

  912.     } else {

  913.         return 100; // invalid stream ID

  914.     }

  915. }

  916. 

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

  918. {

  919.     AVIContext *avi = s->priv_data;

  920.     AVIOContext *pb = s->pb;

  921.     int n;

  922.     unsigned int d[8];

  923.     unsigned int size;

  924.     int64_t i, sync;

  925. 

  926. start_sync:

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

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

  929.         int j;

  930. 

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

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

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

  934. 

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

  936. 

  937.         n = get_stream_idx(d + 2);

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

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

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

  941.             continue;

  942. 

  943.         // parse ix##

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

  945.             // parse JUNK

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

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

  948.             avio_skip(pb, size);

  949.             goto start_sync;

  950.         }

  951. 

  952.         // parse stray LIST

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

  954.             avio_skip(pb, 4);

  955.             goto start_sync;

  956.         }

  957. 

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

  959. 

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

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

  962.             continue;

  963. 

  964.         // detect ##ix chunk and skip

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

  966.             avio_skip(pb, size);

  967.             goto start_sync;

  968.         }

  969. 

  970.         // parse ##dc/##wb

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

  972.             AVStream *st;

  973.             AVIStream *ast;

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

  975.             ast = st->priv_data;

  976. 

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

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

  979.                 AVIStream *ast1 = st1->priv_data;

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

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

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

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

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

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

  986.                      !ast1->prefix_count)) {

  987.                     n   = 1;

  988.                     st  = st1;

  989.                     ast = ast1;

  990.                     av_log(s, AV_LOG_WARNING,

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

  992.                 }

  993.             }

  994. 

  995.             if (!avi->dv_demux &&

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

  997.                  // FIXME: needs a little reordering

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

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

  1000.                 || st->discard >= AVDISCARD_ALL)) {

  1001.                 if (!exit_early) {

  1002.                     ast->frame_offset += get_duration(ast, size);

  1003.                 }

  1004.                 avio_skip(pb, size);

  1005.                 goto start_sync;

  1006.             }

  1007. 

  1008.             if (d[2] == 'p' && d[3] == 'c' && size <= 4 * 256 + 4) {

  1009.                 int k    = avio_r8(pb);

  1010.                 int last = (k + avio_r8(pb) - 1) & 0xFF;

  1011. 

  1012.                 avio_rl16(pb); // flags

  1013. 

  1014.                 // b + (g << 8) + (r << 16);

  1015.                 for (; k <= last; k++)

  1016.                     ast->pal[k] = avio_rb32(pb) >> 8;

  1017. 

  1018.                 ast->has_pal = 1;

  1019.                 goto start_sync;

  1020.             } else if (((ast->prefix_count < 5 || sync + 9 > i) &&

  1021.                         d[2] < 128 && d[3] < 128) ||

  1022.                        d[2] * 256 + d[3] == ast->prefix /* ||

  1023.                        (d[2] == 'd' && d[3] == 'c') ||

  1024.                        (d[2] == 'w' && d[3] == 'b') */) {

  1025.                 if (exit_early)

  1026.                     return 0;

  1027.                 if (d[2] * 256 + d[3] == ast->prefix)

  1028.                     ast->prefix_count++;

  1029.                 else {

  1030.                     ast->prefix       = d[2] * 256 + d[3];

  1031.                     ast->prefix_count = 0;

  1032.                 }

  1033. 

  1034.                 avi->stream_index = n;

  1035.                 ast->packet_size  = size + 8;

  1036.                 ast->remaining    = size;

  1037. 

  1038.                 if (size || !ast->sample_size) {

  1039.                     uint64_t pos = avio_tell(pb) - 8;

  1040.                     if (!st->index_entries || !st->nb_index_entries ||

  1041.                         st->index_entries[st->nb_index_entries - 1].pos < pos) {

  1042.                         av_add_index_entry(st, pos, ast->frame_offset, size,

  1043.                                            0, AVINDEX_KEYFRAME);

  1044.                     }

  1045.                 }

  1046.                 return 0;

  1047.             }

  1048.         }

  1049.     }

  1050. 

  1051.     return AVERROR_EOF;

  1052. }

  1053. 

  1054. static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)

  1055. {

  1056.     AVIContext *avi = s->priv_data;

  1057.     AVIOContext *pb = s->pb;

  1058.     int err;

  1059. #if FF_API_DESTRUCT_PACKET

  1060.     void *dstr;

  1061. #endif

  1062. 

  1063.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1064.         int size = avpriv_dv_get_packet(avi->dv_demux, pkt);

  1065.         if (size >= 0)

  1066.             return size;

  1067.         else

  1068.             goto resync;

  1069.     }

  1070. 

  1071.     if (avi->non_interleaved) {

  1072.         int best_stream_index = 0;

  1073.         AVStream *best_st     = NULL;

  1074.         AVIStream *best_ast;

  1075.         int64_t best_ts = INT64_MAX;

  1076.         int i;

  1077. 

  1078.         for (i = 0; i < s->nb_streams; i++) {

  1079.             AVStream *st   = s->streams[i];

  1080.             AVIStream *ast = st->priv_data;

  1081.             int64_t ts     = ast->frame_offset;

  1082.             int64_t last_ts;

  1083. 

  1084.             if (!st->nb_index_entries)

  1085.                 continue;

  1086. 

  1087.             last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;

  1088.             if (!ast->remaining && ts > last_ts)

  1089.                 continue;

  1090. 

  1091.             ts = av_rescale_q(ts, st->time_base,

  1092.                               (AVRational) { FFMAX(1, ast->sample_size),

  1093.                                              AV_TIME_BASE });

  1094. 

  1095.             av_dlog(s, "%"PRId64" %d/%d %"PRId64"\n", ts,

  1096.                     st->time_base.num, st->time_base.den, ast->frame_offset);

  1097.             if (ts < best_ts) {

  1098.                 best_ts           = ts;

  1099.                 best_st           = st;

  1100.                 best_stream_index = i;

  1101.             }

  1102.         }

  1103.         if (!best_st)

  1104.             return AVERROR_EOF;

  1105. 

  1106.         best_ast = best_st->priv_data;

  1107.         best_ts  = av_rescale_q(best_ts,

  1108.                                 (AVRational) { FFMAX(1, best_ast->sample_size),

  1109.                                                AV_TIME_BASE },

  1110.                                 best_st->time_base);

  1111.         if (best_ast->remaining) {

  1112.             i = av_index_search_timestamp(best_st,

  1113.                                           best_ts,

  1114.                                           AVSEEK_FLAG_ANY |

  1115.                                           AVSEEK_FLAG_BACKWARD);

  1116.         } else {

  1117.             i = av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);

  1118.             if (i >= 0)

  1119.                 best_ast->frame_offset = best_st->index_entries[i].timestamp;

  1120.         }

  1121. 

  1122.         if (i >= 0) {

  1123.             int64_t pos = best_st->index_entries[i].pos;

  1124.             pos += best_ast->packet_size - best_ast->remaining;

  1125.             avio_seek(s->pb, pos + 8, SEEK_SET);

  1126. 

  1127.             assert(best_ast->remaining <= best_ast->packet_size);

  1128. 

  1129.             avi->stream_index = best_stream_index;

  1130.             if (!best_ast->remaining)

  1131.                 best_ast->packet_size =

  1132.                 best_ast->remaining   = best_st->index_entries[i].size;

  1133.         }

  1134.     }

  1135. 

  1136. resync:

  1137.     if (avi->stream_index >= 0) {

  1138.         AVStream *st   = s->streams[avi->stream_index];

  1139.         AVIStream *ast = st->priv_data;

  1140.         int size, err;

  1141. 

  1142.         if (get_subtitle_pkt(s, st, pkt))

  1143.             return 0;

  1144. 

  1145.         // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM

  1146.         if (ast->sample_size <= 1)

  1147.             size = INT_MAX;

  1148.         else if (ast->sample_size < 32)

  1149.             // arbitrary multiplier to avoid tiny packets for raw PCM data

  1150.             size = 1024 * ast->sample_size;

  1151.         else

  1152.             size = ast->sample_size;

  1153. 

  1154.         if (size > ast->remaining)

  1155.             size = ast->remaining;

  1156.         avi->last_pkt_pos = avio_tell(pb);

  1157.         err               = av_get_packet(pb, pkt, size);

  1158.         if (err < 0)

  1159.             return err;

  1160. 

  1161.         if (ast->has_pal && pkt->data && pkt->size < (unsigned)INT_MAX / 2) {

  1162.             uint8_t *pal;

  1163.             pal = av_packet_new_side_data(pkt,

  1164.                                           AV_PKT_DATA_PALETTE,

  1165.                                           AVPALETTE_SIZE);

  1166.             if (!pal) {

  1167.                 av_log(s, AV_LOG_ERROR,

  1168.                        "Failed to allocate data for palette\n");

  1169.             } else {

  1170.                 memcpy(pal, ast->pal, AVPALETTE_SIZE);

  1171.                 ast->has_pal = 0;

  1172.             }

  1173.         }

  1174. 

  1175.         if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1176.             AVBufferRef *avbuf = pkt->buf;

  1177. #if FF_API_DESTRUCT_PACKET

  1178. FF_DISABLE_DEPRECATION_WARNINGS

  1179.             dstr = pkt->destruct;

  1180. FF_ENABLE_DEPRECATION_WARNINGS

  1181. #endif

  1182.             size = avpriv_dv_produce_packet(avi->dv_demux, pkt,

  1183.                                             pkt->data, pkt->size);

  1184. #if FF_API_DESTRUCT_PACKET

  1185. FF_DISABLE_DEPRECATION_WARNINGS

  1186.             pkt->destruct = dstr;

  1187. FF_ENABLE_DEPRECATION_WARNINGS

  1188. #endif

  1189.             pkt->buf    = avbuf;

  1190.             pkt->flags |= AV_PKT_FLAG_KEY;

  1191.             if (size < 0)

  1192.                 av_free_packet(pkt);

  1193.         } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE &&

  1194.                    !st->codec->codec_tag && read_gab2_sub(st, pkt)) {

  1195.             ast->frame_offset++;

  1196.             avi->stream_index = -1;

  1197.             ast->remaining    = 0;

  1198.             goto resync;

  1199.         } else {

  1200.             /* XXX: How to handle B-frames in AVI? */

  1201.             pkt->dts = ast->frame_offset;

  1202. //                pkt->dts += ast->start;

  1203.             if (ast->sample_size)

  1204.                 pkt->dts /= ast->sample_size;

  1205.             av_dlog(s,

  1206.                     "dts:%"PRId64" offset:%"PRId64" %d/%d smpl_siz:%d "

  1207.                     "base:%d st:%d size:%d\n",

  1208.                     pkt->dts,

  1209.                     ast->frame_offset,

  1210.                     ast->scale,

  1211.                     ast->rate,

  1212.                     ast->sample_size,

  1213.                     AV_TIME_BASE,

  1214.                     avi->stream_index,

  1215.                     size);

  1216.             pkt->stream_index = avi->stream_index;

  1217. 

  1218.             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

  1219.                 AVIndexEntry *e;

  1220.                 int index;

  1221.                 assert(st->index_entries);

  1222. 

  1223.                 index = av_index_search_timestamp(st, ast->frame_offset, 0);

  1224.                 e     = &st->index_entries[index];

  1225. 

  1226.                 if (index >= 0 && e->timestamp == ast->frame_offset)

  1227.                     if (e->flags & AVINDEX_KEYFRAME)

  1228.                         pkt->flags |= AV_PKT_FLAG_KEY;

  1229.             } else {

  1230.                 pkt->flags |= AV_PKT_FLAG_KEY;

  1231.             }

  1232.             ast->frame_offset += get_duration(ast, pkt->size);

  1233.         }

  1234.         ast->remaining -= err;

  1235.         if (!ast->remaining) {

  1236.             avi->stream_index = -1;

  1237.             ast->packet_size  = 0;

  1238.         }

  1239. 

  1240.         return 0;

  1241.     }

  1242. 

  1243.     if ((err = avi_sync(s, 0)) < 0)

  1244.         return err;

  1245.     goto resync;

  1246. }

  1247. 

  1248. /* XXX: We make the implicit supposition that the positions are sorted

  1249.  * for each stream. */

  1250. static int avi_read_idx1(AVFormatContext *s, int size)

  1251. {

  1252.     AVIContext *avi = s->priv_data;

  1253.     AVIOContext *pb = s->pb;

  1254.     int nb_index_entries, i;

  1255.     AVStream *st;

  1256.     AVIStream *ast;

  1257.     unsigned int index, tag, flags, pos, len, first_packet = 1;

  1258.     unsigned last_pos = -1;

  1259.     int64_t idx1_pos, first_packet_pos = 0, data_offset = 0;

  1260. 

  1261.     nb_index_entries = size / 16;

  1262.     if (nb_index_entries <= 0)

  1263.         return AVERROR_INVALIDDATA;

  1264. 

  1265.     idx1_pos = avio_tell(pb);

  1266.     avio_seek(pb, avi->movi_list + 4, SEEK_SET);

  1267.     if (avi_sync(s, 1) == 0)

  1268.         first_packet_pos = avio_tell(pb) - 8;

  1269.     avi->stream_index = -1;

  1270.     avio_seek(pb, idx1_pos, SEEK_SET);

  1271. 

  1272.     /* Read the entries and sort them in each stream component. */

  1273.     for (i = 0; i < nb_index_entries; i++) {

  1274.         tag   = avio_rl32(pb);

  1275.         flags = avio_rl32(pb);

  1276.         pos   = avio_rl32(pb);

  1277.         len   = avio_rl32(pb);

  1278.         av_dlog(s, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",

  1279.                 i, tag, flags, pos, len);

  1280. 

  1281.         index  = ((tag      & 0xff) - '0') * 10;

  1282.         index +=  (tag >> 8 & 0xff) - '0';

  1283.         if (index >= s->nb_streams)

  1284.             continue;

  1285.         st  = s->streams[index];

  1286.         ast = st->priv_data;

  1287. 

  1288.         if (first_packet && first_packet_pos && len) {

  1289.             data_offset  = first_packet_pos - pos;

  1290.             first_packet = 0;

  1291.         }

  1292.         pos += data_offset;

  1293. 

  1294.         av_dlog(s, "%d cum_len=%"PRId64"\n", len, ast->cum_len);

  1295. 

  1296.         if (pb->eof_reached)

  1297.             return AVERROR_INVALIDDATA;

  1298. 

  1299.         if (last_pos == pos)

  1300.             avi->non_interleaved = 1;

  1301.         else if (len || !ast->sample_size)

  1302.             av_add_index_entry(st, pos, ast->cum_len, len, 0,

  1303.                                (flags & AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);

  1304.         ast->cum_len += get_duration(ast, len);

  1305.         last_pos      = pos;

  1306.     }

  1307.     return 0;

  1308. }

  1309. 

  1310. static int guess_ni_flag(AVFormatContext *s)

  1311. {

  1312.     int i;

  1313.     int64_t last_start = 0;

  1314.     int64_t first_end  = INT64_MAX;

  1315.     int64_t oldpos     = avio_tell(s->pb);

  1316. 

  1317.     for (i = 0; i < s->nb_streams; i++) {

  1318.         AVStream *st = s->streams[i];

  1319.         int n        = st->nb_index_entries;

  1320.         unsigned int size;

  1321. 

  1322.         if (n <= 0)

  1323.             continue;

  1324. 

  1325.         if (n >= 2) {

  1326.             int64_t pos = st->index_entries[0].pos;

  1327.             avio_seek(s->pb, pos + 4, SEEK_SET);

  1328.             size = avio_rl32(s->pb);

  1329.             if (pos + size > st->index_entries[1].pos)

  1330.                 last_start = INT64_MAX;

  1331.         }

  1332. 

  1333.         if (st->index_entries[0].pos > last_start)

  1334.             last_start = st->index_entries[0].pos;

  1335.         if (st->index_entries[n - 1].pos < first_end)

  1336.             first_end = st->index_entries[n - 1].pos;

  1337.     }

  1338.     avio_seek(s->pb, oldpos, SEEK_SET);

  1339.     return last_start > first_end;

  1340. }

  1341. 

  1342. static int avi_load_index(AVFormatContext *s)

  1343. {

  1344.     AVIContext *avi = s->priv_data;

  1345.     AVIOContext *pb = s->pb;

  1346.     uint32_t tag, size;

  1347.     int64_t pos = avio_tell(pb);

  1348.     int ret     = -1;

  1349. 

  1350.     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)

  1351.         goto the_end; // maybe truncated file

  1352.     av_dlog(s, "movi_end=0x%"PRIx64"\n", avi->movi_end);

  1353.     for (;;) {

  1354.         if (pb->eof_reached)

  1355.             break;

  1356.         tag  = avio_rl32(pb);

  1357.         size = avio_rl32(pb);

  1358.         av_dlog(s, "tag=%c%c%c%c size=0x%x\n",

  1359.                  tag        & 0xff,

  1360.                 (tag >>  8) & 0xff,

  1361.                 (tag >> 16) & 0xff,

  1362.                 (tag >> 24) & 0xff,

  1363.                 size);

  1364. 

  1365.         if (tag == MKTAG('i', 'd', 'x', '1') &&

  1366.             avi_read_idx1(s, size) >= 0) {

  1367.             ret = 0;

  1368.             break;

  1369.         }

  1370. 

  1371.         size += (size & 1);

  1372.         if (avio_skip(pb, size) < 0)

  1373.             break; // something is wrong here

  1374.     }

  1375. 

  1376. the_end:

  1377.     avio_seek(pb, pos, SEEK_SET);

  1378.     return ret;

  1379. }

  1380. 

  1381. static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)

  1382. {

  1383.     AVIStream *ast2 = st2->priv_data;

  1384.     int64_t ts2     = av_rescale_q(timestamp, st->time_base, st2->time_base);

  1385.     av_free_packet(&ast2->sub_pkt);

  1386.     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||

  1387.         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)

  1388.         ff_read_packet(ast2->sub_ctx, &ast2->sub_pkt);

  1389. }

  1390. 

  1391. static int avi_read_seek(AVFormatContext *s, int stream_index,

  1392.                          int64_t timestamp, int flags)

  1393. {

  1394.     AVIContext *avi = s->priv_data;

  1395.     AVStream *st;

  1396.     int i, index;

  1397.     int64_t pos;

  1398.     AVIStream *ast;

  1399. 

  1400.     /* Does not matter which stream is requested dv in avi has the

  1401.      * stream information in the first video stream.

  1402.      */

  1403.     if (avi->dv_demux)

  1404.         stream_index = 0;

  1405. 

  1406.     if (!avi->index_loaded) {

  1407.         /* we only load the index on demand */

  1408.         avi_load_index(s);

  1409.         avi->index_loaded = 1;

  1410.     }

  1411. 

  1412.     st    = s->streams[stream_index];

  1413.     ast   = st->priv_data;

  1414.     index = av_index_search_timestamp(st,

  1415.                                       timestamp * FFMAX(ast->sample_size, 1),

  1416.                                       flags);

  1417.     if (index < 0)

  1418.         return AVERROR_INVALIDDATA;

  1419. 

  1420.     /* find the position */

  1421.     pos       = st->index_entries[index].pos;

  1422.     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);

  1423. 

  1424.     av_dlog(s, "XX %"PRId64" %d %"PRId64"\n",

  1425.             timestamp, index, st->index_entries[index].timestamp);

  1426. 

  1427.     if (CONFIG_DV_DEMUXER && avi->dv_demux) {

  1428.         /* One and only one real stream for DV in AVI, and it has video  */

  1429.         /* offsets. Calling with other stream indexes should have failed */

  1430.         /* the av_index_search_timestamp call above.                     */

  1431. 

  1432.         /* Feed the DV video stream version of the timestamp to the */

  1433.         /* DV demux so it can synthesize correct timestamps.        */

  1434.         ff_dv_offset_reset(avi->dv_demux, timestamp);

  1435. 

  1436.         avio_seek(s->pb, pos, SEEK_SET);

  1437.         avi->stream_index = -1;

  1438.         return 0;

  1439.     }

  1440. 

  1441.     for (i = 0; i < s->nb_streams; i++) {

  1442.         AVStream *st2   = s->streams[i];

  1443.         AVIStream *ast2 = st2->priv_data;

  1444. 

  1445.         ast2->packet_size =

  1446.         ast2->remaining   = 0;

  1447. 

  1448.         if (ast2->sub_ctx) {

  1449.             seek_subtitle(st, st2, timestamp);

  1450.             continue;

  1451.         }

  1452. 

  1453.         if (st2->nb_index_entries <= 0)

  1454.             continue;

  1455. 

  1456. //        assert(st2->codec->block_align);

  1457.         assert((int64_t)st2->time_base.num * ast2->rate ==

  1458.                (int64_t)st2->time_base.den * ast2->scale);

  1459.         index = av_index_search_timestamp(st2,

  1460.                                           av_rescale_q(timestamp,

  1461.                                                        st->time_base,

  1462.                                                        st2->time_base) *

  1463.                                           FFMAX(ast2->sample_size, 1),

  1464.                                           flags | AVSEEK_FLAG_BACKWARD);

  1465.         if (index < 0)

  1466.             index = 0;

  1467. 

  1468.         if (!avi->non_interleaved) {

  1469.             while (index > 0 && st2->index_entries[index].pos > pos)

  1470.                 index--;

  1471.             while (index + 1 < st2->nb_index_entries &&

  1472.                    st2->index_entries[index].pos < pos)

  1473.                 index++;

  1474.         }

  1475. 

  1476.         av_dlog(s, "%"PRId64" %d %"PRId64"\n",

  1477.                 timestamp, index, st2->index_entries[index].timestamp);

  1478.         /* extract the current frame number */

  1479.         ast2->frame_offset = st2->index_entries[index].timestamp;

  1480.     }

  1481. 

  1482.     /* do the seek */

  1483.     avio_seek(s->pb, pos, SEEK_SET);

  1484.     avi->stream_index = -1;

  1485.     return 0;

  1486. }

  1487. 

  1488. static int avi_read_close(AVFormatContext *s)

  1489. {

  1490.     int i;

  1491.     AVIContext *avi = s->priv_data;

  1492. 

  1493.     for (i = 0; i < s->nb_streams; i++) {

  1494.         AVStream *st   = s->streams[i];

  1495.         AVIStream *ast = st->priv_data;

  1496.         if (ast) {

  1497.             if (ast->sub_ctx) {

  1498.                 av_freep(&ast->sub_ctx->pb);

  1499.                 avformat_close_input(&ast->sub_ctx);

  1500.             }

  1501.             av_free(ast->sub_buffer);

  1502.             av_free_packet(&ast->sub_pkt);

  1503.         }

  1504.     }

  1505. 

  1506.     av_free(avi->dv_demux);

  1507. 

  1508.     return 0;

  1509. }

  1510. 

  1511. static int avi_probe(AVProbeData *p)

  1512. {

  1513.     int i;

  1514. 

  1515.     /* check file header */

  1516.     for (i = 0; avi_headers[i][0]; i++)

  1517.         if (!memcmp(p->buf,     avi_headers[i],     4) &&

  1518.             !memcmp(p->buf + 8, avi_headers[i] + 4, 4))

  1519.             return AVPROBE_SCORE_MAX;

  1520. 

  1521.     return 0;

  1522. }

  1523. 

  1524. AVInputFormat ff_avi_demuxer = {

  1525.     .name           = "avi",

  1526.     .long_name      = NULL_IF_CONFIG_SMALL("AVI (Audio Video Interleaved)"),

  1527.     .priv_data_size = sizeof(AVIContext),

  1528.     .read_probe     = avi_probe,

  1529.     .read_header    = avi_read_header,

  1530.     .read_packet    = avi_read_packet,

  1531.     .read_close     = avi_read_close,

  1532.     .read_seek      = avi_read_seek,

  1533. };