chasing indexing error

1 files changed, 0 insertions, 1739 deletions

diff --git a/ffmpeg/libavformat/avidec.c b/ffmpeg/libavformat/avidec.c
deleted file mode 100644
index 17eb245..0000000
--- a/ffmpeg/libavformat/avidec.c
+++ /dev/null
@@ -1,1739 +0,0 @@
-/*
- * AVI demuxer
- * Copyright (c) 2001 Fabrice Bellard
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <stdint.h>
-
-#include "libavutil/avassert.h"
-#include "libavutil/avstring.h"
-#include "libavutil/bswap.h"
-#include "libavutil/opt.h"
-#include "libavutil/dict.h"
-#include "libavutil/internal.h"
-#include "libavutil/intreadwrite.h"
-#include "libavutil/mathematics.h"
-#include "avformat.h"
-#include "avi.h"
-#include "dv.h"
-#include "internal.h"
-#include "riff.h"
-
-typedef struct AVIStream {
-    int64_t frame_offset;   /* current frame (video) or byte (audio) counter
-                             * (used to compute the pts) */
-    int remaining;
-    int packet_size;
-
-    uint32_t scale;
-    uint32_t rate;
-    int sample_size;        /* size of one sample (or packet)
-                             * (in the rate/scale sense) in bytes */
-
-    int64_t cum_len;        /* temporary storage (used during seek) */
-    int prefix;             /* normally 'd'<<8 + 'c' or 'w'<<8 + 'b' */
-    int prefix_count;
-    uint32_t pal[256];
-    int has_pal;
-    int dshow_block_align;  /* block align variable used to emulate bugs in
-                             * the MS dshow demuxer */
-
-    AVFormatContext *sub_ctx;
-    AVPacket sub_pkt;
-    uint8_t *sub_buffer;
-
-    int64_t seek_pos;
-} AVIStream;
-
-typedef struct {
-    const AVClass *class;
-    int64_t riff_end;
-    int64_t movi_end;
-    int64_t fsize;
-    int64_t io_fsize;
-    int64_t movi_list;
-    int64_t last_pkt_pos;
-    int index_loaded;
-    int is_odml;
-    int non_interleaved;
-    int stream_index;
-    DVDemuxContext *dv_demux;
-    int odml_depth;
-    int use_odml;
-#define MAX_ODML_DEPTH 1000
-    int64_t dts_max;
-} AVIContext;
-
-
-static const AVOption options[] = {
-    { "use_odml", "use odml index", offsetof(AVIContext, use_odml), AV_OPT_TYPE_INT, {.i64 = 1}, -1, 1, AV_OPT_FLAG_DECODING_PARAM},
-    { NULL },
-};
-
-static const AVClass demuxer_class = {
-    .class_name = "avi",
-    .item_name  = av_default_item_name,
-    .option     = options,
-    .version    = LIBAVUTIL_VERSION_INT,
-    .category   = AV_CLASS_CATEGORY_DEMUXER,
-};
-
-
-static const char avi_headers[][8] = {
-    { 'R', 'I', 'F', 'F', 'A', 'V', 'I', ' '  },
-    { 'R', 'I', 'F', 'F', 'A', 'V', 'I', 'X'  },
-    { 'R', 'I', 'F', 'F', 'A', 'V', 'I', 0x19 },
-    { 'O', 'N', '2', ' ', 'O', 'N', '2', 'f'  },
-    { 'R', 'I', 'F', 'F', 'A', 'M', 'V', ' '  },
-    { 0 }
-};
-
-static const AVMetadataConv avi_metadata_conv[] = {
-    { "strn", "title" },
-    { 0 },
-};
-
-static int avi_load_index(AVFormatContext *s);
-static int guess_ni_flag(AVFormatContext *s);
-
-#define print_tag(str, tag, size)                        \
-    av_dlog(NULL, "pos:%"PRIX64" %s: tag=%c%c%c%c size=0x%x\n", \
-            avio_tell(pb), str, tag & 0xff,              \
-            (tag >> 8) & 0xff,                           \
-            (tag >> 16) & 0xff,                          \
-            (tag >> 24) & 0xff,                          \
-            size)
-
-static inline int get_duration(AVIStream *ast, int len)
-{
-    if (ast->sample_size)
-        return len;
-    else if (ast->dshow_block_align)
-        return (len + ast->dshow_block_align - 1) / ast->dshow_block_align;
-    else
-        return 1;
-}
-
-static int get_riff(AVFormatContext *s, AVIOContext *pb)
-{
-    AVIContext *avi = s->priv_data;
-    char header[8];
-    int i;
-
-    /* check RIFF header */
-    avio_read(pb, header, 4);
-    avi->riff_end  = avio_rl32(pb); /* RIFF chunk size */
-    avi->riff_end += avio_tell(pb); /* RIFF chunk end */
-    avio_read(pb, header + 4, 4);
-
-    for (i = 0; avi_headers[i][0]; i++)
-        if (!memcmp(header, avi_headers[i], 8))
-            break;
-    if (!avi_headers[i][0])
-        return AVERROR_INVALIDDATA;
-
-    if (header[7] == 0x19)
-        av_log(s, AV_LOG_INFO,
-               "This file has been generated by a totally broken muxer.\n");
-
-    return 0;
-}
-
-static int read_braindead_odml_indx(AVFormatContext *s, int frame_num)
-{
-    AVIContext *avi     = s->priv_data;
-    AVIOContext *pb     = s->pb;
-    int longs_pre_entry = avio_rl16(pb);
-    int index_sub_type  = avio_r8(pb);
-    int index_type      = avio_r8(pb);
-    int entries_in_use  = avio_rl32(pb);
-    int chunk_id        = avio_rl32(pb);
-    int64_t base        = avio_rl64(pb);
-    int stream_id       = ((chunk_id      & 0xFF) - '0') * 10 +
-                          ((chunk_id >> 8 & 0xFF) - '0');
-    AVStream *st;
-    AVIStream *ast;
-    int i;
-    int64_t last_pos = -1;
-    int64_t filesize = avi->fsize;
-
-    av_dlog(s,
-            "longs_pre_entry:%d index_type:%d entries_in_use:%d "
-            "chunk_id:%X base:%16"PRIX64"\n",
-            longs_pre_entry,
-            index_type,
-            entries_in_use,
-            chunk_id,
-            base);
-
-    if (stream_id >= s->nb_streams || stream_id < 0)
-        return AVERROR_INVALIDDATA;
-    st  = s->streams[stream_id];
-    ast = st->priv_data;
-
-    if (index_sub_type)
-        return AVERROR_INVALIDDATA;
-
-    avio_rl32(pb);
-
-    if (index_type && longs_pre_entry != 2)
-        return AVERROR_INVALIDDATA;
-    if (index_type > 1)
-        return AVERROR_INVALIDDATA;
-
-    if (filesize > 0 && base >= filesize) {
-        av_log(s, AV_LOG_ERROR, "ODML index invalid\n");
-        if (base >> 32 == (base & 0xFFFFFFFF) &&
-            (base & 0xFFFFFFFF) < filesize    &&
-            filesize <= 0xFFFFFFFF)
-            base &= 0xFFFFFFFF;
-        else
-            return AVERROR_INVALIDDATA;
-    }
-
-    for (i = 0; i < entries_in_use; i++) {
-        if (index_type) {
-            int64_t pos = avio_rl32(pb) + base - 8;
-            int len     = avio_rl32(pb);
-            int key     = len >= 0;
-            len &= 0x7FFFFFFF;
-
-#ifdef DEBUG_SEEK
-            av_log(s, AV_LOG_ERROR, "pos:%"PRId64", len:%X\n", pos, len);
-#endif
-            if (url_feof(pb))
-                return AVERROR_INVALIDDATA;
-
-            if (last_pos == pos || pos == base - 8)
-                avi->non_interleaved = 1;
-            if (last_pos != pos && (len || !ast->sample_size))
-                av_add_index_entry(st, pos, ast->cum_len, len, 0,
-                                   key ? AVINDEX_KEYFRAME : 0);
-
-            ast->cum_len += get_duration(ast, len);
-            last_pos      = pos;
-        } else {
-            int64_t offset, pos;
-            int duration;
-            offset = avio_rl64(pb);
-            avio_rl32(pb);       /* size */
-            duration = avio_rl32(pb);
-
-            if (url_feof(pb))
-                return AVERROR_INVALIDDATA;
-
-            pos = avio_tell(pb);
-
-            if (avi->odml_depth > MAX_ODML_DEPTH) {
-                av_log(s, AV_LOG_ERROR, "Too deeply nested ODML indexes\n");
-                return AVERROR_INVALIDDATA;
-            }
-
-            if (avio_seek(pb, offset + 8, SEEK_SET) < 0)
-                return -1;
-            avi->odml_depth++;
-            read_braindead_odml_indx(s, frame_num);
-            avi->odml_depth--;
-            frame_num += duration;
-
-            if (avio_seek(pb, pos, SEEK_SET) < 0) {
-                av_log(s, AV_LOG_ERROR, "Failed to restore position after reading index\n");
-                return -1;
-            }
-
-        }
-    }
-    avi->index_loaded = 2;
-    return 0;
-}
-
-static void clean_index(AVFormatContext *s)
-{
-    int i;
-    int64_t j;
-
-    for (i = 0; i < s->nb_streams; i++) {
-        AVStream *st   = s->streams[i];
-        AVIStream *ast = st->priv_data;
-        int n          = st->nb_index_entries;
-        int max        = ast->sample_size;
-        int64_t pos, size, ts;
-
-        if (n != 1 || ast->sample_size == 0)
-            continue;
-
-        while (max < 1024)
-            max += max;
-
-        pos  = st->index_entries[0].pos;
-        size = st->index_entries[0].size;
-        ts   = st->index_entries[0].timestamp;
-
-        for (j = 0; j < size; j += max)
-            av_add_index_entry(st, pos + j, ts + j, FFMIN(max, size - j), 0,
-                               AVINDEX_KEYFRAME);
-    }
-}
-
-static int avi_read_tag(AVFormatContext *s, AVStream *st, uint32_t tag,
-                        uint32_t size)
-{
-    AVIOContext *pb = s->pb;
-    char key[5]     = { 0 };
-    char *value;
-
-    size += (size & 1);
-
-    if (size == UINT_MAX)
-        return AVERROR(EINVAL);
-    value = av_malloc(size + 1);
-    if (!value)
-        return AVERROR(ENOMEM);
-    avio_read(pb, value, size);
-    value[size] = 0;
-
-    AV_WL32(key, tag);
-
-    return av_dict_set(st ? &st->metadata : &s->metadata, key, value,
-                       AV_DICT_DONT_STRDUP_VAL);
-}
-
-static const char months[12][4] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
-                                    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
-
-static void avi_metadata_creation_time(AVDictionary **metadata, char *date)
-{
-    char month[4], time[9], buffer[64];
-    int i, day, year;
-    /* parse standard AVI date format (ie. "Mon Mar 10 15:04:43 2003") */
-    if (sscanf(date, "%*3s%*[ ]%3s%*[ ]%2d%*[ ]%8s%*[ ]%4d",
-               month, &day, time, &year) == 4) {
-        for (i = 0; i < 12; i++)
-            if (!av_strcasecmp(month, months[i])) {
-                snprintf(buffer, sizeof(buffer), "%.4d-%.2d-%.2d %s",
-                         year, i + 1, day, time);
-                av_dict_set(metadata, "creation_time", buffer, 0);
-            }
-    } else if (date[4] == '/' && date[7] == '/') {
-        date[4] = date[7] = '-';
-        av_dict_set(metadata, "creation_time", date, 0);
-    }
-}
-
-static void avi_read_nikon(AVFormatContext *s, uint64_t end)
-{
-    while (avio_tell(s->pb) < end) {
-        uint32_t tag  = avio_rl32(s->pb);
-        uint32_t size = avio_rl32(s->pb);
-        switch (tag) {
-        case MKTAG('n', 'c', 't', 'g'):  /* Nikon Tags */
-        {
-            uint64_t tag_end = avio_tell(s->pb) + size;
-            while (avio_tell(s->pb) < tag_end) {
-                uint16_t tag     = avio_rl16(s->pb);
-                uint16_t size    = avio_rl16(s->pb);
-                const char *name = NULL;
-                char buffer[64]  = { 0 };
-                size -= avio_read(s->pb, buffer,
-                                  FFMIN(size, sizeof(buffer) - 1));
-                switch (tag) {
-                case 0x03:
-                    name = "maker";
-                    break;
-                case 0x04:
-                    name = "model";
-                    break;
-                case 0x13:
-                    name = "creation_time";
-                    if (buffer[4] == ':' && buffer[7] == ':')
-                        buffer[4] = buffer[7] = '-';
-                    break;
-                }
-                if (name)
-                    av_dict_set(&s->metadata, name, buffer, 0);
-                avio_skip(s->pb, size);
-            }
-            break;
-        }
-        default:
-            avio_skip(s->pb, size);
-            break;
-        }
-    }
-}
-
-static int avi_read_header(AVFormatContext *s)
-{
-    AVIContext *avi = s->priv_data;
-    AVIOContext *pb = s->pb;
-    unsigned int tag, tag1, handler;
-    int codec_type, stream_index, frame_period;
-    unsigned int size;
-    int i;
-    AVStream *st;
-    AVIStream *ast      = NULL;
-    int avih_width      = 0, avih_height = 0;
-    int amv_file_format = 0;
-    uint64_t list_end   = 0;
-    int ret;
-    AVDictionaryEntry *dict_entry;
-
-    avi->stream_index = -1;
-
-    ret = get_riff(s, pb);
-    if (ret < 0)
-        return ret;
-
-    av_log(avi, AV_LOG_DEBUG, "use odml:%d\n", avi->use_odml);
-
-    avi->io_fsize = avi->fsize = avio_size(pb);
-    if (avi->fsize <= 0 || avi->fsize < avi->riff_end)
-        avi->fsize = avi->riff_end == 8 ? INT64_MAX : avi->riff_end;
-
-    /* first list tag */
-    stream_index = -1;
-    codec_type   = -1;
-    frame_period = 0;
-    for (;;) {
-        if (url_feof(pb))
-            goto fail;
-        tag  = avio_rl32(pb);
-        size = avio_rl32(pb);
-
-        print_tag("tag", tag, size);
-
-        switch (tag) {
-        case MKTAG('L', 'I', 'S', 'T'):
-            list_end = avio_tell(pb) + size;
-            /* Ignored, except at start of video packets. */
-            tag1 = avio_rl32(pb);
-
-            print_tag("list", tag1, 0);
-
-            if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
-                avi->movi_list = avio_tell(pb) - 4;
-                if (size)
-                    avi->movi_end = avi->movi_list + size + (size & 1);
-                else
-                    avi->movi_end = avi->fsize;
-                av_dlog(NULL, "movi end=%"PRIx64"\n", avi->movi_end);
-                goto end_of_header;
-            } else if (tag1 == MKTAG('I', 'N', 'F', 'O'))
-                ff_read_riff_info(s, size - 4);
-            else if (tag1 == MKTAG('n', 'c', 'd', 't'))
-                avi_read_nikon(s, list_end);
-
-            break;
-        case MKTAG('I', 'D', 'I', 'T'):
-        {
-            unsigned char date[64] = { 0 };
-            size += (size & 1);
-            size -= avio_read(pb, date, FFMIN(size, sizeof(date) - 1));
-            avio_skip(pb, size);
-            avi_metadata_creation_time(&s->metadata, date);
-            break;
-        }
-        case MKTAG('d', 'm', 'l', 'h'):
-            avi->is_odml = 1;
-            avio_skip(pb, size + (size & 1));
-            break;
-        case MKTAG('a', 'm', 'v', 'h'):
-            amv_file_format = 1;
-        case MKTAG('a', 'v', 'i', 'h'):
-            /* AVI header */
-            /* using frame_period is bad idea */
-            frame_period = avio_rl32(pb);
-            avio_rl32(pb); /* max. bytes per second */
-            avio_rl32(pb);
-            avi->non_interleaved |= avio_rl32(pb) & AVIF_MUSTUSEINDEX;
-
-            avio_skip(pb, 2 * 4);
-            avio_rl32(pb);
-            avio_rl32(pb);
-            avih_width  = avio_rl32(pb);
-            avih_height = avio_rl32(pb);
-
-            avio_skip(pb, size - 10 * 4);
-            break;
-        case MKTAG('s', 't', 'r', 'h'):
-            /* stream header */
-
-            tag1    = avio_rl32(pb);
-            handler = avio_rl32(pb); /* codec tag */
-
-            if (tag1 == MKTAG('p', 'a', 'd', 's')) {
-                avio_skip(pb, size - 8);
-                break;
-            } else {
-                stream_index++;
-                st = avformat_new_stream(s, NULL);
-                if (!st)
-                    goto fail;
-
-                st->id = stream_index;
-                ast    = av_mallocz(sizeof(AVIStream));
-                if (!ast)
-                    goto fail;
-                st->priv_data = ast;
-            }
-            if (amv_file_format)
-                tag1 = stream_index ? MKTAG('a', 'u', 'd', 's')
-                                    : MKTAG('v', 'i', 'd', 's');
-
-            print_tag("strh", tag1, -1);
-
-            if (tag1 == MKTAG('i', 'a', 'v', 's') ||
-                tag1 == MKTAG('i', 'v', 'a', 's')) {
-                int64_t dv_dur;
-
-                /* After some consideration -- I don't think we
-                 * have to support anything but DV in type1 AVIs. */
-                if (s->nb_streams != 1)
-                    goto fail;
-
-                if (handler != MKTAG('d', 'v', 's', 'd') &&
-                    handler != MKTAG('d', 'v', 'h', 'd') &&
-                    handler != MKTAG('d', 'v', 's', 'l'))
-                    goto fail;
-
-                ast = s->streams[0]->priv_data;
-                av_freep(&s->streams[0]->codec->extradata);
-                av_freep(&s->streams[0]->codec);
-                if (s->streams[0]->info)
-                    av_freep(&s->streams[0]->info->duration_error);
-                av_freep(&s->streams[0]->info);
-                av_freep(&s->streams[0]);
-                s->nb_streams = 0;
-                if (CONFIG_DV_DEMUXER) {
-                    avi->dv_demux = avpriv_dv_init_demux(s);
-                    if (!avi->dv_demux)
-                        goto fail;
-                } else
-                    goto fail;
-                s->streams[0]->priv_data = ast;
-                avio_skip(pb, 3 * 4);
-                ast->scale = avio_rl32(pb);
-                ast->rate  = avio_rl32(pb);
-                avio_skip(pb, 4);  /* start time */
-
-                dv_dur = avio_rl32(pb);
-                if (ast->scale > 0 && ast->rate > 0 && dv_dur > 0) {
-                    dv_dur     *= AV_TIME_BASE;
-                    s->duration = av_rescale(dv_dur, ast->scale, ast->rate);
-                }
-                /* else, leave duration alone; timing estimation in utils.c
-                 * will make a guess based on bitrate. */
-
-                stream_index = s->nb_streams - 1;
-                avio_skip(pb, size - 9 * 4);
-                break;
-            }
-
-            av_assert0(stream_index < s->nb_streams);
-            st->codec->stream_codec_tag = handler;
-
-            avio_rl32(pb); /* flags */
-            avio_rl16(pb); /* priority */
-            avio_rl16(pb); /* language */
-            avio_rl32(pb); /* initial frame */
-            ast->scale = avio_rl32(pb);
-            ast->rate  = avio_rl32(pb);
-            if (!(ast->scale && ast->rate)) {
-                av_log(s, AV_LOG_WARNING,
-                       "scale/rate is %u/%u which is invalid. "
-                       "(This file has been generated by broken software.)\n",
-                       ast->scale,
-                       ast->rate);
-                if (frame_period) {
-                    ast->rate  = 1000000;
-                    ast->scale = frame_period;
-                } else {
-                    ast->rate  = 25;
-                    ast->scale = 1;
-                }
-            }
-            avpriv_set_pts_info(st, 64, ast->scale, ast->rate);
-
-            ast->cum_len  = avio_rl32(pb); /* start */
-            st->nb_frames = avio_rl32(pb);
-
-            st->start_time = 0;
-            avio_rl32(pb); /* buffer size */
-            avio_rl32(pb); /* quality */
-            if (ast->cum_len*ast->scale/ast->rate > 3600) {
-                av_log(s, AV_LOG_ERROR, "crazy start time, iam scared, giving up\n");
-                return AVERROR_INVALIDDATA;
-            }
-            ast->sample_size = avio_rl32(pb); /* sample ssize */
-            ast->cum_len    *= FFMAX(1, ast->sample_size);
-            av_dlog(s, "%"PRIu32" %"PRIu32" %d\n",
-                    ast->rate, ast->scale, ast->sample_size);
-
-            switch (tag1) {
-            case MKTAG('v', 'i', 'd', 's'):
-                codec_type = AVMEDIA_TYPE_VIDEO;
-
-                ast->sample_size = 0;
-                break;
-            case MKTAG('a', 'u', 'd', 's'):
-                codec_type = AVMEDIA_TYPE_AUDIO;
-                break;
-            case MKTAG('t', 'x', 't', 's'):
-                codec_type = AVMEDIA_TYPE_SUBTITLE;
-                break;
-            case MKTAG('d', 'a', 't', 's'):
-                codec_type = AVMEDIA_TYPE_DATA;
-                break;
-            default:
-                av_log(s, AV_LOG_INFO, "unknown stream type %X\n", tag1);
-            }
-            if (ast->sample_size == 0) {
-                st->duration = st->nb_frames;
-                if (st->duration > 0 && avi->io_fsize > 0 && avi->riff_end > avi->io_fsize) {
-                    av_log(s, AV_LOG_DEBUG, "File is truncated adjusting duration\n");
-                    st->duration = av_rescale(st->duration, avi->io_fsize, avi->riff_end);
-                }
-            }
-            ast->frame_offset = ast->cum_len;
-            avio_skip(pb, size - 12 * 4);
-            break;
-        case MKTAG('s', 't', 'r', 'f'):
-            /* stream header */
-            if (!size)
-                break;
-            if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {
-                avio_skip(pb, size);
-            } else {
-                uint64_t cur_pos = avio_tell(pb);
-                unsigned esize;
-                if (cur_pos < list_end)
-                    size = FFMIN(size, list_end - cur_pos);
-                st = s->streams[stream_index];
-                if (st->codec->codec_type != AVMEDIA_TYPE_UNKNOWN) {
-                    avio_skip(pb, size);
-                    break;
-                }
-                switch (codec_type) {
-                case AVMEDIA_TYPE_VIDEO:
-                    if (amv_file_format) {
-                        st->codec->width      = avih_width;
-                        st->codec->height     = avih_height;
-                        st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
-                        st->codec->codec_id   = AV_CODEC_ID_AMV;
-                        avio_skip(pb, size);
-                        break;
-                    }
-                    tag1 = ff_get_bmp_header(pb, st, &esize);
-
-                    if (tag1 == MKTAG('D', 'X', 'S', 'B') ||
-                        tag1 == MKTAG('D', 'X', 'S', 'A')) {
-                        st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
-                        st->codec->codec_tag  = tag1;
-                        st->codec->codec_id   = AV_CODEC_ID_XSUB;
-                        break;
-                    }
-
-                    if (size > 10 * 4 && size < (1 << 30) && size < avi->fsize) {
-                        if (esize == size-1 && (esize&1)) {
-                            st->codec->extradata_size = esize - 10 * 4;
-                        } else
-                            st->codec->extradata_size =  size - 10 * 4;
-                        if (ff_get_extradata(st->codec, pb, st->codec->extradata_size) < 0)
-                            return AVERROR(ENOMEM);
-                    }
-
-                    // FIXME: check if the encoder really did this correctly
-                    if (st->codec->extradata_size & 1)
-                        avio_r8(pb);
-
-                    /* Extract palette from extradata if bpp <= 8.
-                     * This code assumes that extradata contains only palette.
-                     * This is true for all paletted codecs implemented in
-                     * FFmpeg. */
-                    if (st->codec->extradata_size &&
-                        (st->codec->bits_per_coded_sample <= 8)) {
-                        int pal_size = (1 << st->codec->bits_per_coded_sample) << 2;
-                        const uint8_t *pal_src;
-
-                        pal_size = FFMIN(pal_size, st->codec->extradata_size);
-                        pal_src  = st->codec->extradata +
-                                   st->codec->extradata_size - pal_size;
-                        for (i = 0; i < pal_size / 4; i++)
-                            ast->pal[i] = 0xFFU<<24 | AV_RL32(pal_src+4*i);
-                        ast->has_pal = 1;
-                    }
-
-                    print_tag("video", tag1, 0);
-
-                    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
-                    st->codec->codec_tag  = tag1;
-                    st->codec->codec_id   = ff_codec_get_id(ff_codec_bmp_tags,
-                                                            tag1);
-                    /* This is needed to get the pict type which is necessary
-                     * for generating correct pts. */
-                    st->need_parsing = AVSTREAM_PARSE_HEADERS;
-
-                    if (st->codec->codec_tag == 0 && st->codec->height > 0 &&
-                        st->codec->extradata_size < 1U << 30) {
-                        st->codec->extradata_size += 9;
-                        if ((ret = av_reallocp(&st->codec->extradata,
-                                               st->codec->extradata_size +
-                                               FF_INPUT_BUFFER_PADDING_SIZE)) < 0) {
-                            st->codec->extradata_size = 0;
-                            return ret;
-                        } else
-                            memcpy(st->codec->extradata + st->codec->extradata_size - 9,
-                                   "BottomUp", 9);
-                    }
-                    st->codec->height = FFABS(st->codec->height);
-
-//                    avio_skip(pb, size - 5 * 4);
-                    break;
-                case AVMEDIA_TYPE_AUDIO:
-                    ret = ff_get_wav_header(pb, st->codec, size);
-                    if (ret < 0)
-                        return ret;
-                    ast->dshow_block_align = st->codec->block_align;
-                    if (ast->sample_size && st->codec->block_align &&
-                        ast->sample_size != st->codec->block_align) {
-                        av_log(s,
-                               AV_LOG_WARNING,
-                               "sample size (%d) != block align (%d)\n",
-                               ast->sample_size,
-                               st->codec->block_align);
-                        ast->sample_size = st->codec->block_align;
-                    }
-                    /* 2-aligned
-                     * (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
-                    if (size & 1)
-                        avio_skip(pb, 1);
-                    /* Force parsing as several audio frames can be in
-                     * one packet and timestamps refer to packet start. */
-                    st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;
-                    /* ADTS header is in extradata, AAC without header must be
-                     * stored as exact frames. Parser not needed and it will
-                     * fail. */
-                    if (st->codec->codec_id == AV_CODEC_ID_AAC &&
-                        st->codec->extradata_size)
-                        st->need_parsing = AVSTREAM_PARSE_NONE;
-                    /* AVI files with Xan DPCM audio (wrongly) declare PCM
-                     * audio in the header but have Axan as stream_code_tag. */
-                    if (st->codec->stream_codec_tag == AV_RL32("Axan")) {
-                        st->codec->codec_id  = AV_CODEC_ID_XAN_DPCM;
-                        st->codec->codec_tag = 0;
-                        ast->dshow_block_align = 0;
-                    }
-                    if (amv_file_format) {
-                        st->codec->codec_id    = AV_CODEC_ID_ADPCM_IMA_AMV;
-                        ast->dshow_block_align = 0;
-                    }
-                    if (st->codec->codec_id == AV_CODEC_ID_AAC && ast->dshow_block_align <= 4 && ast->dshow_block_align) {
-                        av_log(s, AV_LOG_DEBUG, "overriding invalid dshow_block_align of %d\n", ast->dshow_block_align);
-                        ast->dshow_block_align = 0;
-                    }
-                    if (st->codec->codec_id == AV_CODEC_ID_AAC && ast->dshow_block_align == 1024 && ast->sample_size == 1024 ||
-                       st->codec->codec_id == AV_CODEC_ID_AAC && ast->dshow_block_align == 4096 && ast->sample_size == 4096 ||
-                       st->codec->codec_id == AV_CODEC_ID_MP3 && ast->dshow_block_align == 1152 && ast->sample_size == 1152) {
-                        av_log(s, AV_LOG_DEBUG, "overriding sample_size\n");
-                        ast->sample_size = 0;
-                    }
-                    break;
-                case AVMEDIA_TYPE_SUBTITLE:
-                    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
-                    st->request_probe= 1;
-                    avio_skip(pb, size);
-                    break;
-                default:
-                    st->codec->codec_type = AVMEDIA_TYPE_DATA;
-                    st->codec->codec_id   = AV_CODEC_ID_NONE;
-                    st->codec->codec_tag  = 0;
-                    avio_skip(pb, size);
-                    break;
-                }
-            }
-            break;
-        case MKTAG('s', 't', 'r', 'd'):
-            if (stream_index >= (unsigned)s->nb_streams
-                || s->streams[stream_index]->codec->extradata_size
-                || s->streams[stream_index]->codec->codec_tag == MKTAG('H','2','6','4')) {
-                avio_skip(pb, size);
-            } else {
-                uint64_t cur_pos = avio_tell(pb);
-                if (cur_pos < list_end)
-                    size = FFMIN(size, list_end - cur_pos);
-                st = s->streams[stream_index];
-
-                if (size<(1<<30)) {
-                    if (ff_get_extradata(st->codec, pb, size) < 0)
-                        return AVERROR(ENOMEM);
-                }
-
-                if (st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
-                    avio_r8(pb);
-            }
-            break;
-        case MKTAG('i', 'n', 'd', 'x'):
-            i = avio_tell(pb);
-            if (pb->seekable && !(s->flags & AVFMT_FLAG_IGNIDX) &&
-                avi->use_odml &&
-                read_braindead_odml_indx(s, 0) < 0 &&
-                (s->error_recognition & AV_EF_EXPLODE))
-                goto fail;
-            avio_seek(pb, i + size, SEEK_SET);
-            break;
-        case MKTAG('v', 'p', 'r', 'p'):
-            if (stream_index < (unsigned)s->nb_streams && size > 9 * 4) {
-                AVRational active, active_aspect;
-
-                st = s->streams[stream_index];
-                avio_rl32(pb);
-                avio_rl32(pb);
-                avio_rl32(pb);
-                avio_rl32(pb);
-                avio_rl32(pb);
-
-                active_aspect.den = avio_rl16(pb);
-                active_aspect.num = avio_rl16(pb);
-                active.num        = avio_rl32(pb);
-                active.den        = avio_rl32(pb);
-                avio_rl32(pb); // nbFieldsPerFrame
-
-                if (active_aspect.num && active_aspect.den &&
-                    active.num && active.den) {
-                    st->sample_aspect_ratio = av_div_q(active_aspect, active);
-                    av_dlog(s, "vprp %d/%d %d/%d\n",
-                            active_aspect.num, active_aspect.den,
-                            active.num, active.den);
-                }
-                size -= 9 * 4;
-            }
-            avio_skip(pb, size);
-            break;
-        case MKTAG('s', 't', 'r', 'n'):
-            if (s->nb_streams) {
-                ret = avi_read_tag(s, s->streams[s->nb_streams - 1], tag, size);
-                if (ret < 0)
-                    return ret;
-                break;
-            }
-        default:
-            if (size > 1000000) {
-                av_log(s, AV_LOG_ERROR,
-                       "Something went wrong during header parsing, "
-                       "I will ignore it and try to continue anyway.\n");
-                if (s->error_recognition & AV_EF_EXPLODE)
-                    goto fail;
-                avi->movi_list = avio_tell(pb) - 4;
-                avi->movi_end  = avi->fsize;
-                goto end_of_header;
-            }
-            /* skip tag */
-            size += (size & 1);
-            avio_skip(pb, size);
-            break;
-        }
-    }
-
-end_of_header:
-    /* check stream number */
-    if (stream_index != s->nb_streams - 1) {
-
-fail:
-        return AVERROR_INVALIDDATA;
-    }
-
-    if (!avi->index_loaded && pb->seekable)
-        avi_load_index(s);
-    avi->index_loaded    |= 1;
-    avi->non_interleaved |= guess_ni_flag(s) | (s->flags & AVFMT_FLAG_SORT_DTS);
-
-    dict_entry = av_dict_get(s->metadata, "ISFT", NULL, 0);
-    if (dict_entry && !strcmp(dict_entry->value, "PotEncoder"))
-        for (i = 0; i < s->nb_streams; i++) {
-            AVStream *st = s->streams[i];
-            if (   st->codec->codec_id == AV_CODEC_ID_MPEG1VIDEO
-                || st->codec->codec_id == AV_CODEC_ID_MPEG2VIDEO)
-                st->need_parsing = AVSTREAM_PARSE_FULL;
-        }
-
-    for (i = 0; i < s->nb_streams; i++) {
-        AVStream *st = s->streams[i];
-        if (st->nb_index_entries)
-            break;
-    }
-    // DV-in-AVI cannot be non-interleaved, if set this must be
-    // a mis-detection.
-    if (avi->dv_demux)
-        avi->non_interleaved = 0;
-    if (i == s->nb_streams && avi->non_interleaved) {
-        av_log(s, AV_LOG_WARNING,
-               "Non-interleaved AVI without index, switching to interleaved\n");
-        avi->non_interleaved = 0;
-    }
-
-    if (avi->non_interleaved) {
-        av_log(s, AV_LOG_INFO, "non-interleaved AVI\n");
-        clean_index(s);
-    }
-
-    ff_metadata_conv_ctx(s, NULL, avi_metadata_conv);
-    ff_metadata_conv_ctx(s, NULL, ff_riff_info_conv);
-
-    return 0;
-}
-
-static int read_gab2_sub(AVStream *st, AVPacket *pkt)
-{
-    if (pkt->size >= 7 &&
-        !strcmp(pkt->data, "GAB2") && AV_RL16(pkt->data + 5) == 2) {
-        uint8_t desc[256];
-        int score      = AVPROBE_SCORE_EXTENSION, ret;
-        AVIStream *ast = st->priv_data;
-        AVInputFormat *sub_demuxer;
-        AVRational time_base;
-        AVIOContext *pb = avio_alloc_context(pkt->data + 7,
-                                             pkt->size - 7,
-                                             0, NULL, NULL, NULL, NULL);
-        AVProbeData pd;
-        unsigned int desc_len = avio_rl32(pb);
-
-        if (desc_len > pb->buf_end - pb->buf_ptr)
-            goto error;
-
-        ret = avio_get_str16le(pb, desc_len, desc, sizeof(desc));
-        avio_skip(pb, desc_len - ret);
-        if (*desc)
-            av_dict_set(&st->metadata, "title", desc, 0);
-
-        avio_rl16(pb);   /* flags? */
-        avio_rl32(pb);   /* data size */
-
-        pd = (AVProbeData) { .buf      = pb->buf_ptr,
-                             .buf_size = pb->buf_end - pb->buf_ptr };
-        if (!(sub_demuxer = av_probe_input_format2(&pd, 1, &score)))
-            goto error;
-
-        if (!(ast->sub_ctx = avformat_alloc_context()))
-            goto error;
-
-        ast->sub_ctx->pb = pb;
-        if (!avformat_open_input(&ast->sub_ctx, "", sub_demuxer, NULL)) {
-            ff_read_packet(ast->sub_ctx, &ast->sub_pkt);
-            *st->codec = *ast->sub_ctx->streams[0]->codec;
-            ast->sub_ctx->streams[0]->codec->extradata = NULL;
-            time_base = ast->sub_ctx->streams[0]->time_base;
-            avpriv_set_pts_info(st, 64, time_base.num, time_base.den);
-        }
-        ast->sub_buffer = pkt->data;
-        memset(pkt, 0, sizeof(*pkt));
-        return 1;
-
-error:
-        av_freep(&pb);
-    }
-    return 0;
-}
-
-static AVStream *get_subtitle_pkt(AVFormatContext *s, AVStream *next_st,
-                                  AVPacket *pkt)
-{
-    AVIStream *ast, *next_ast = next_st->priv_data;
-    int64_t ts, next_ts, ts_min = INT64_MAX;
-    AVStream *st, *sub_st = NULL;
-    int i;
-
-    next_ts = av_rescale_q(next_ast->frame_offset, next_st->time_base,
-                           AV_TIME_BASE_Q);
-
-    for (i = 0; i < s->nb_streams; i++) {
-        st  = s->streams[i];
-        ast = st->priv_data;
-        if (st->discard < AVDISCARD_ALL && ast && ast->sub_pkt.data) {
-            ts = av_rescale_q(ast->sub_pkt.dts, st->time_base, AV_TIME_BASE_Q);
-            if (ts <= next_ts && ts < ts_min) {
-                ts_min = ts;
-                sub_st = st;
-            }
-        }
-    }
-
-    if (sub_st) {
-        ast               = sub_st->priv_data;
-        *pkt              = ast->sub_pkt;
-        pkt->stream_index = sub_st->index;
-
-        if (ff_read_packet(ast->sub_ctx, &ast->sub_pkt) < 0)
-            ast->sub_pkt.data = NULL;
-    }
-    return sub_st;
-}
-
-static int get_stream_idx(unsigned *d)
-{
-    if (d[0] >= '0' && d[0] <= '9' &&
-        d[1] >= '0' && d[1] <= '9') {
-        return (d[0] - '0') * 10 + (d[1] - '0');
-    } else {
-        return 100; // invalid stream ID
-    }
-}
-
-/**
- *
- * @param exit_early set to 1 to just gather packet position without making the changes needed to actually read & return the packet
- */
-static int avi_sync(AVFormatContext *s, int exit_early)
-{
-    AVIContext *avi = s->priv_data;
-    AVIOContext *pb = s->pb;
-    int n;
-    unsigned int d[8];
-    unsigned int size;
-    int64_t i, sync;
-
-start_sync:
-    memset(d, -1, sizeof(d));
-    for (i = sync = avio_tell(pb); !url_feof(pb); i++) {
-        int j;
-
-        for (j = 0; j < 7; j++)
-            d[j] = d[j + 1];
-        d[7] = avio_r8(pb);
-
-        size = d[4] + (d[5] << 8) + (d[6] << 16) + (d[7] << 24);
-
-        n = get_stream_idx(d + 2);
-        av_dlog(s, "%X %X %X %X %X %X %X %X %"PRId64" %u %d\n",
-                d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
-        if (i*(avi->io_fsize>0) + (uint64_t)size > avi->fsize || d[0] > 127)
-            continue;
-
-        // parse ix##
-        if ((d[0] == 'i' && d[1] == 'x' && n < s->nb_streams) ||
-            // parse JUNK
-            (d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K') ||
-            (d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')) {
-            avio_skip(pb, size);
-            goto start_sync;
-        }
-
-        // parse stray LIST
-        if (d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T') {
-            avio_skip(pb, 4);
-            goto start_sync;
-        }
-
-        n = avi->dv_demux ? 0 : get_stream_idx(d);
-
-        if (!((i - avi->last_pkt_pos) & 1) &&
-            get_stream_idx(d + 1) < s->nb_streams)
-            continue;
-
-        // detect ##ix chunk and skip
-        if (d[2] == 'i' && d[3] == 'x' && n < s->nb_streams) {
-            avio_skip(pb, size);
-            goto start_sync;
-        }
-
-        // parse ##dc/##wb
-        if (n < s->nb_streams) {
-            AVStream *st;
-            AVIStream *ast;
-            st  = s->streams[n];
-            ast = st->priv_data;
-
-            if (!ast) {
-                av_log(s, AV_LOG_WARNING, "Skiping foreign stream %d packet\n", n);
-                continue;
-            }
-
-            if (s->nb_streams >= 2) {
-                AVStream *st1   = s->streams[1];
-                AVIStream *ast1 = st1->priv_data;
-                // workaround for broken small-file-bug402.avi
-                if (   d[2] == 'w' && d[3] == 'b'
-                   && n == 0
-                   && st ->codec->codec_type == AVMEDIA_TYPE_VIDEO
-                   && st1->codec->codec_type == AVMEDIA_TYPE_AUDIO
-                   && ast->prefix == 'd'*256+'c'
-                   && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)
-                  ) {
-                    n   = 1;
-                    st  = st1;
-                    ast = ast1;
-                    av_log(s, AV_LOG_WARNING,
-                           "Invalid stream + prefix combination, assuming audio.\n");
-                }
-            }
-
-            if (!avi->dv_demux &&
-                ((st->discard >= AVDISCARD_DEFAULT && size == 0) /* ||
-                 // FIXME: needs a little reordering
-                 (st->discard >= AVDISCARD_NONKEY &&
-                 !(pkt->flags & AV_PKT_FLAG_KEY)) */
-                || st->discard >= AVDISCARD_ALL)) {
-                if (!exit_early) {
-                    ast->frame_offset += get_duration(ast, size);
-                    avio_skip(pb, size);
-                    goto start_sync;
-                }
-            }
-
-            if (d[2] == 'p' && d[3] == 'c' && size <= 4 * 256 + 4) {
-                int k    = avio_r8(pb);
-                int last = (k + avio_r8(pb) - 1) & 0xFF;
-
-                avio_rl16(pb); // flags
-
-                // b + (g << 8) + (r << 16);
-                for (; k <= last; k++)
-                    ast->pal[k] = 0xFFU<<24 | avio_rb32(pb)>>8;
-
-                ast->has_pal = 1;
-                goto start_sync;
-            } else if (((ast->prefix_count < 5 || sync + 9 > i) &&
-                        d[2] < 128 && d[3] < 128) ||
-                       d[2] * 256 + d[3] == ast->prefix /* ||
-                       (d[2] == 'd' && d[3] == 'c') ||
-                       (d[2] == 'w' && d[3] == 'b') */) {
-                if (exit_early)
-                    return 0;
-                if (d[2] * 256 + d[3] == ast->prefix)
-                    ast->prefix_count++;
-                else {
-                    ast->prefix       = d[2] * 256 + d[3];
-                    ast->prefix_count = 0;
-                }
-
-                avi->stream_index = n;
-                ast->packet_size  = size + 8;
-                ast->remaining    = size;
-
-                if (size || !ast->sample_size) {
-                    uint64_t pos = avio_tell(pb) - 8;
-                    if (!st->index_entries || !st->nb_index_entries ||
-                        st->index_entries[st->nb_index_entries - 1].pos < pos) {
-                        av_add_index_entry(st, pos, ast->frame_offset, size,
-                                           0, AVINDEX_KEYFRAME);
-                    }
-                }
-                return 0;
-            }
-        }
-    }
-
-    if (pb->error)
-        return pb->error;
-    return AVERROR_EOF;
-}
-
-static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
-{
-    AVIContext *avi = s->priv_data;
-    AVIOContext *pb = s->pb;
-    int err;
-#if FF_API_DESTRUCT_PACKET
-    void *dstr;
-#endif
-
-    if (CONFIG_DV_DEMUXER && avi->dv_demux) {
-        int size = avpriv_dv_get_packet(avi->dv_demux, pkt);
-        if (size >= 0)
-            return size;
-        else
-            goto resync;
-    }
-
-    if (avi->non_interleaved) {
-        int best_stream_index = 0;
-        AVStream *best_st     = NULL;
-        AVIStream *best_ast;
-        int64_t best_ts = INT64_MAX;
-        int i;
-
-        for (i = 0; i < s->nb_streams; i++) {
-            AVStream *st   = s->streams[i];
-            AVIStream *ast = st->priv_data;
-            int64_t ts     = ast->frame_offset;
-            int64_t last_ts;
-
-            if (!st->nb_index_entries)
-                continue;
-
-            last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;
-            if (!ast->remaining && ts > last_ts)
-                continue;
-
-            ts = av_rescale_q(ts, st->time_base,
-                              (AVRational) { FFMAX(1, ast->sample_size),
-                                             AV_TIME_BASE });
-
-            av_dlog(s, "%"PRId64" %d/%d %"PRId64"\n", ts,
-                    st->time_base.num, st->time_base.den, ast->frame_offset);
-            if (ts < best_ts) {
-                best_ts           = ts;
-                best_st           = st;
-                best_stream_index = i;
-            }
-        }
-        if (!best_st)
-            return AVERROR_EOF;
-
-        best_ast = best_st->priv_data;
-        best_ts  = best_ast->frame_offset;
-        if (best_ast->remaining) {
-            i = av_index_search_timestamp(best_st,
-                                          best_ts,
-                                          AVSEEK_FLAG_ANY |
-                                          AVSEEK_FLAG_BACKWARD);
-        } else {
-            i = av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
-            if (i >= 0)
-                best_ast->frame_offset = best_st->index_entries[i].timestamp;
-        }
-
-        if (i >= 0) {
-            int64_t pos = best_st->index_entries[i].pos;
-            pos += best_ast->packet_size - best_ast->remaining;
-            if (avio_seek(s->pb, pos + 8, SEEK_SET) < 0)
-              return AVERROR_EOF;
-
-            av_assert0(best_ast->remaining <= best_ast->packet_size);
-
-            avi->stream_index = best_stream_index;
-            if (!best_ast->remaining)
-                best_ast->packet_size =
-                best_ast->remaining   = best_st->index_entries[i].size;
-        }
-        else
-          return AVERROR_EOF;
-    }
-
-resync:
-    if (avi->stream_index >= 0) {
-        AVStream *st   = s->streams[avi->stream_index];
-        AVIStream *ast = st->priv_data;
-        int size, err;
-
-        if (get_subtitle_pkt(s, st, pkt))
-            return 0;
-
-        // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
-        if (ast->sample_size <= 1)
-            size = INT_MAX;
-        else if (ast->sample_size < 32)
-            // arbitrary multiplier to avoid tiny packets for raw PCM data
-            size = 1024 * ast->sample_size;
-        else
-            size = ast->sample_size;
-
-        if (size > ast->remaining)
-            size = ast->remaining;
-        avi->last_pkt_pos = avio_tell(pb);
-        err               = av_get_packet(pb, pkt, size);
-        if (err < 0)
-            return err;
-        size = err;
-
-        if (ast->has_pal && pkt->size < (unsigned)INT_MAX / 2) {
-            uint8_t *pal;
-            pal = av_packet_new_side_data(pkt,
-                                          AV_PKT_DATA_PALETTE,
-                                          AVPALETTE_SIZE);
-            if (!pal) {
-                av_log(s, AV_LOG_ERROR,
-                       "Failed to allocate data for palette\n");
-            } else {
-                memcpy(pal, ast->pal, AVPALETTE_SIZE);
-                ast->has_pal = 0;
-            }
-        }
-
-        if (CONFIG_DV_DEMUXER && avi->dv_demux) {
-            AVBufferRef *avbuf = pkt->buf;
-#if FF_API_DESTRUCT_PACKET
-FF_DISABLE_DEPRECATION_WARNINGS
-            dstr = pkt->destruct;
-FF_ENABLE_DEPRECATION_WARNINGS
-#endif
-            size = avpriv_dv_produce_packet(avi->dv_demux, pkt,
-                                            pkt->data, pkt->size, pkt->pos);
-#if FF_API_DESTRUCT_PACKET
-FF_DISABLE_DEPRECATION_WARNINGS
-            pkt->destruct = dstr;
-FF_ENABLE_DEPRECATION_WARNINGS
-#endif
-            pkt->buf    = avbuf;
-            pkt->flags |= AV_PKT_FLAG_KEY;
-            if (size < 0)
-                av_free_packet(pkt);
-        } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE &&
-                   !st->codec->codec_tag && read_gab2_sub(st, pkt)) {
-            ast->frame_offset++;
-            avi->stream_index = -1;
-            ast->remaining    = 0;
-            goto resync;
-        } else {
-            /* XXX: How to handle B-frames in AVI? */
-            pkt->dts = ast->frame_offset;
-//                pkt->dts += ast->start;
-            if (ast->sample_size)
-                pkt->dts /= ast->sample_size;
-            av_dlog(s,
-                    "dts:%"PRId64" offset:%"PRId64" %d/%d smpl_siz:%d "
-                    "base:%d st:%d size:%d\n",
-                    pkt->dts,
-                    ast->frame_offset,
-                    ast->scale,
-                    ast->rate,
-                    ast->sample_size,
-                    AV_TIME_BASE,
-                    avi->stream_index,
-                    size);
-            pkt->stream_index = avi->stream_index;
-
-            if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && st->index_entries) {
-                AVIndexEntry *e;
-                int index;
-
-                index = av_index_search_timestamp(st, ast->frame_offset, 0);
-                e     = &st->index_entries[index];
-
-                if (index >= 0 && e->timestamp == ast->frame_offset) {
-                    if (index == st->nb_index_entries-1) {
-                        int key=1;
-                        int i;
-                        uint32_t state=-1;
-                        for (i=0; i<FFMIN(size,256); i++) {
-                            if (st->codec->codec_id == AV_CODEC_ID_MPEG4) {
-                                if (state == 0x1B6) {
-                                    key= !(pkt->data[i]&0xC0);
-                                    break;
-                                }
-                            }else
-                                break;
-                            state= (state<<8) + pkt->data[i];
-                        }
-                        if (!key)
-                            e->flags &= ~AVINDEX_KEYFRAME;
-                    }
-                    if (e->flags & AVINDEX_KEYFRAME)
-                        pkt->flags |= AV_PKT_FLAG_KEY;
-                }
-            } else {
-                pkt->flags |= AV_PKT_FLAG_KEY;
-            }
-            ast->frame_offset += get_duration(ast, pkt->size);
-        }
-        ast->remaining -= err;
-        if (!ast->remaining) {
-            avi->stream_index = -1;
-            ast->packet_size  = 0;
-        }
-
-        if (!avi->non_interleaved && pkt->pos >= 0 && ast->seek_pos > pkt->pos) {
-            av_free_packet(pkt);
-            goto resync;
-        }
-        ast->seek_pos= 0;
-
-        if (!avi->non_interleaved && st->nb_index_entries>1 && avi->index_loaded>1) {
-            int64_t dts= av_rescale_q(pkt->dts, st->time_base, AV_TIME_BASE_Q);
-
-            if (avi->dts_max - dts > 2*AV_TIME_BASE) {
-                avi->non_interleaved= 1;
-                av_log(s, AV_LOG_INFO, "Switching to NI mode, due to poor interleaving\n");
-            }else if (avi->dts_max < dts)
-                avi->dts_max = dts;
-        }
-
-        return 0;
-    }
-
-    if ((err = avi_sync(s, 0)) < 0)
-        return err;
-    goto resync;
-}
-
-/* XXX: We make the implicit supposition that the positions are sorted
- * for each stream. */
-static int avi_read_idx1(AVFormatContext *s, int size)
-{
-    AVIContext *avi = s->priv_data;
-    AVIOContext *pb = s->pb;
-    int nb_index_entries, i;
-    AVStream *st;
-    AVIStream *ast;
-    unsigned int index, tag, flags, pos, len, first_packet = 1;
-    unsigned last_pos = -1;
-    unsigned last_idx = -1;
-    int64_t idx1_pos, first_packet_pos = 0, data_offset = 0;
-    int anykey = 0;
-
-    nb_index_entries = size / 16;
-    if (nb_index_entries <= 0)
-        return AVERROR_INVALIDDATA;
-
-    idx1_pos = avio_tell(pb);
-    avio_seek(pb, avi->movi_list + 4, SEEK_SET);
-    if (avi_sync(s, 1) == 0)
-        first_packet_pos = avio_tell(pb) - 8;
-    avi->stream_index = -1;
-    avio_seek(pb, idx1_pos, SEEK_SET);
-
-    if (s->nb_streams == 1 && s->streams[0]->codec->codec_tag == AV_RL32("MMES")) {
-        first_packet_pos = 0;
-        data_offset = avi->movi_list;
-    }
-
-    /* Read the entries and sort them in each stream component. */
-    for (i = 0; i < nb_index_entries; i++) {
-        if (url_feof(pb))
-            return -1;
-
-        tag   = avio_rl32(pb);
-        flags = avio_rl32(pb);
-        pos   = avio_rl32(pb);
-        len   = avio_rl32(pb);
-        av_dlog(s, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
-                i, tag, flags, pos, len);
-
-        index  = ((tag      & 0xff) - '0') * 10;
-        index +=  (tag >> 8 & 0xff) - '0';
-        if (index >= s->nb_streams)
-            continue;
-        st  = s->streams[index];
-        ast = st->priv_data;
-
-        if (first_packet && first_packet_pos) {
-            data_offset  = first_packet_pos - pos;
-            first_packet = 0;
-        }
-        pos += data_offset;
-
-        av_dlog(s, "%d cum_len=%"PRId64"\n", len, ast->cum_len);
-
-        // even if we have only a single stream, we should
-        // switch to non-interleaved to get correct timestamps
-        if (last_pos == pos)
-            avi->non_interleaved = 1;
-        if (last_idx != pos && len) {
-            av_add_index_entry(st, pos, ast->cum_len, len, 0,
-                               (flags & AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
-            last_idx= pos;
-        }
-        ast->cum_len += get_duration(ast, len);
-        last_pos      = pos;
-        anykey       |= flags&AVIIF_INDEX;
-    }
-    if (!anykey) {
-        for (index = 0; index < s->nb_streams; index++) {
-            st = s->streams[index];
-            if (st->nb_index_entries)
-                st->index_entries[0].flags |= AVINDEX_KEYFRAME;
-        }
-    }
-    return 0;
-}
-
-static int guess_ni_flag(AVFormatContext *s)
-{
-    int i;
-    int64_t last_start = 0;
-    int64_t first_end  = INT64_MAX;
-    int64_t oldpos     = avio_tell(s->pb);
-    int *idx;
-    int64_t min_pos, pos;
-
-    for (i = 0; i < s->nb_streams; i++) {
-        AVStream *st = s->streams[i];
-        int n        = st->nb_index_entries;
-        unsigned int size;
-
-        if (n <= 0)
-            continue;
-
-        if (n >= 2) {
-            int64_t pos = st->index_entries[0].pos;
-            avio_seek(s->pb, pos + 4, SEEK_SET);
-            size = avio_rl32(s->pb);
-            if (pos + size > st->index_entries[1].pos)
-                last_start = INT64_MAX;
-        }
-
-        if (st->index_entries[0].pos > last_start)
-            last_start = st->index_entries[0].pos;
-        if (st->index_entries[n - 1].pos < first_end)
-            first_end = st->index_entries[n - 1].pos;
-    }
-    avio_seek(s->pb, oldpos, SEEK_SET);
-    if (last_start > first_end)
-        return 1;
-    idx= av_calloc(s->nb_streams, sizeof(*idx));
-    if (!idx)
-        return 0;
-    for (min_pos=pos=0; min_pos!=INT64_MAX; pos= min_pos+1LU) {
-        int64_t max_dts = INT64_MIN/2, min_dts= INT64_MAX/2;
-        min_pos = INT64_MAX;
-
-        for (i=0; i<s->nb_streams; i++) {
-            AVStream *st = s->streams[i];
-            AVIStream *ast = st->priv_data;
-            int n= st->nb_index_entries;
-            while (idx[i]<n && st->index_entries[idx[i]].pos < pos)
-                idx[i]++;
-            if (idx[i] < n) {
-                min_dts = FFMIN(min_dts, av_rescale_q(st->index_entries[idx[i]].timestamp/FFMAX(ast->sample_size, 1), st->time_base, AV_TIME_BASE_Q));
-                min_pos = FFMIN(min_pos, st->index_entries[idx[i]].pos);
-            }
-            if (idx[i])
-                max_dts = FFMAX(max_dts, av_rescale_q(st->index_entries[idx[i]-1].timestamp/FFMAX(ast->sample_size, 1), st->time_base, AV_TIME_BASE_Q));
-        }
-        if (max_dts - min_dts > 2*AV_TIME_BASE) {
-            av_free(idx);
-            return 1;
-        }
-    }
-    av_free(idx);
-    return 0;
-}
-
-static int avi_load_index(AVFormatContext *s)
-{
-    AVIContext *avi = s->priv_data;
-    AVIOContext *pb = s->pb;
-    uint32_t tag, size;
-    int64_t pos = avio_tell(pb);
-    int64_t next;
-    int ret     = -1;
-
-    if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)
-        goto the_end; // maybe truncated file
-    av_dlog(s, "movi_end=0x%"PRIx64"\n", avi->movi_end);
-    for (;;) {
-        tag  = avio_rl32(pb);
-        size = avio_rl32(pb);
-        if (url_feof(pb))
-            break;
-        next = avio_tell(pb) + size + (size & 1);
-
-        av_dlog(s, "tag=%c%c%c%c size=0x%x\n",
-                 tag        & 0xff,
-                (tag >>  8) & 0xff,
-                (tag >> 16) & 0xff,
-                (tag >> 24) & 0xff,
-                size);
-
-        if (tag == MKTAG('i', 'd', 'x', '1') &&
-            avi_read_idx1(s, size) >= 0) {
-            avi->index_loaded=2;
-            ret = 0;
-        }else if (tag == MKTAG('L', 'I', 'S', 'T')) {
-            uint32_t tag1 = avio_rl32(pb);
-
-            if (tag1 == MKTAG('I', 'N', 'F', 'O'))
-                ff_read_riff_info(s, size - 4);
-        }else if (!ret)
-            break;
-
-        if (avio_seek(pb, next, SEEK_SET) < 0)
-            break; // something is wrong here
-    }
-
-the_end:
-    avio_seek(pb, pos, SEEK_SET);
-    return ret;
-}
-
-static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)
-{
-    AVIStream *ast2 = st2->priv_data;
-    int64_t ts2     = av_rescale_q(timestamp, st->time_base, st2->time_base);
-    av_free_packet(&ast2->sub_pkt);
-    if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||
-        avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)
-        ff_read_packet(ast2->sub_ctx, &ast2->sub_pkt);
-}
-
-static int avi_read_seek(AVFormatContext *s, int stream_index,
-                         int64_t timestamp, int flags)
-{
-    AVIContext *avi = s->priv_data;
-    AVStream *st;
-    int i, index;
-    int64_t pos, pos_min;
-    AVIStream *ast;
-
-    /* Does not matter which stream is requested dv in avi has the
-     * stream information in the first video stream.
-     */
-    if (avi->dv_demux)
-        stream_index = 0;
-
-    if (!avi->index_loaded) {
-        /* we only load the index on demand */
-        avi_load_index(s);
-        avi->index_loaded |= 1;
-    }
-    av_assert0(stream_index >= 0);
-
-    st    = s->streams[stream_index];
-    ast   = st->priv_data;
-    index = av_index_search_timestamp(st,
-                                      timestamp * FFMAX(ast->sample_size, 1),
-                                      flags);
-    if (index < 0) {
-        if (st->nb_index_entries > 0)
-            av_log(s, AV_LOG_DEBUG, "Failed to find timestamp %"PRId64 " in index %"PRId64 " .. %"PRId64 "\n",
-                   timestamp * FFMAX(ast->sample_size, 1),
-                   st->index_entries[0].timestamp,
-                   st->index_entries[st->nb_index_entries - 1].timestamp);
-        return AVERROR_INVALIDDATA;
-    }
-
-    /* find the position */
-    pos       = st->index_entries[index].pos;
-    timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);
-
-    av_dlog(s, "XX %"PRId64" %d %"PRId64"\n",
-            timestamp, index, st->index_entries[index].timestamp);
-
-    if (CONFIG_DV_DEMUXER && avi->dv_demux) {
-        /* One and only one real stream for DV in AVI, and it has video  */
-        /* offsets. Calling with other stream indexes should have failed */
-        /* the av_index_search_timestamp call above.                     */
-
-        if (avio_seek(s->pb, pos, SEEK_SET) < 0)
-            return -1;
-
-        /* Feed the DV video stream version of the timestamp to the */
-        /* DV demux so it can synthesize correct timestamps.        */
-        ff_dv_offset_reset(avi->dv_demux, timestamp);
-
-        avi->stream_index = -1;
-        return 0;
-    }
-
-    pos_min = pos;
-    for (i = 0; i < s->nb_streams; i++) {
-        AVStream *st2   = s->streams[i];
-        AVIStream *ast2 = st2->priv_data;
-
-        ast2->packet_size =
-        ast2->remaining   = 0;
-
-        if (ast2->sub_ctx) {
-            seek_subtitle(st, st2, timestamp);
-            continue;
-        }
-
-        if (st2->nb_index_entries <= 0)
-            continue;
-
-//        av_assert1(st2->codec->block_align);
-        av_assert0((int64_t)st2->time_base.num * ast2->rate ==
-                   (int64_t)st2->time_base.den * ast2->scale);
-        index = av_index_search_timestamp(st2,
-                                          av_rescale_q(timestamp,
-                                                       st->time_base,
-                                                       st2->time_base) *
-                                          FFMAX(ast2->sample_size, 1),
-                                          flags |
-                                          AVSEEK_FLAG_BACKWARD |
-                                          (st2->codec->codec_type != AVMEDIA_TYPE_VIDEO ? AVSEEK_FLAG_ANY : 0));
-        if (index < 0)
-            index = 0;
-        ast2->seek_pos = st2->index_entries[index].pos;
-        pos_min = FFMIN(pos_min,ast2->seek_pos);
-    }
-    for (i = 0; i < s->nb_streams; i++) {
-        AVStream *st2 = s->streams[i];
-        AVIStream *ast2 = st2->priv_data;
-
-        if (ast2->sub_ctx || st2->nb_index_entries <= 0)
-            continue;
-
-        index = av_index_search_timestamp(
-                st2,
-                av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),
-                flags | AVSEEK_FLAG_BACKWARD | (st2->codec->codec_type != AVMEDIA_TYPE_VIDEO ? AVSEEK_FLAG_ANY : 0));
-        if (index < 0)
-            index = 0;
-        while (!avi->non_interleaved && index>0 && st2->index_entries[index-1].pos >= pos_min)
-            index--;
-        ast2->frame_offset = st2->index_entries[index].timestamp;
-    }
-
-    /* do the seek */
-    if (avio_seek(s->pb, pos_min, SEEK_SET) < 0) {
-        av_log(s, AV_LOG_ERROR, "Seek failed\n");
-        return -1;
-    }
-    avi->stream_index = -1;
-    avi->dts_max      = INT_MIN;
-    return 0;
-}
-
-static int avi_read_close(AVFormatContext *s)
-{
-    int i;
-    AVIContext *avi = s->priv_data;
-
-    for (i = 0; i < s->nb_streams; i++) {
-        AVStream *st   = s->streams[i];
-        AVIStream *ast = st->priv_data;
-        if (ast) {
-            if (ast->sub_ctx) {
-                av_freep(&ast->sub_ctx->pb);
-                avformat_close_input(&ast->sub_ctx);
-            }
-            av_free(ast->sub_buffer);
-            av_free_packet(&ast->sub_pkt);
-        }
-    }
-
-    av_free(avi->dv_demux);
-
-    return 0;
-}
-
-static int avi_probe(AVProbeData *p)
-{
-    int i;
-
-    /* check file header */
-    for (i = 0; avi_headers[i][0]; i++)
-        if (!memcmp(p->buf,     avi_headers[i],     4) &&
-            !memcmp(p->buf + 8, avi_headers[i] + 4, 4))
-            return AVPROBE_SCORE_MAX;
-
-    return 0;
-}
-
-AVInputFormat ff_avi_demuxer = {
-    .name           = "avi",
-    .long_name      = NULL_IF_CONFIG_SMALL("AVI (Audio Video Interleaved)"),
-    .priv_data_size = sizeof(AVIContext),
-    .read_probe     = avi_probe,
-    .read_header    = avi_read_header,
-    .read_packet    = avi_read_packet,
-    .read_close     = avi_read_close,
-    .read_seek      = avi_read_seek,
-    .priv_class = &demuxer_class,
-};