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https://git.ffmpeg.org/ffmpeg.git
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706 lines
22 KiB
C
706 lines
22 KiB
C
/*
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* AVI decoder.
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* Copyright (c) 2001 Fabrice Bellard.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include "avformat.h"
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#include "avi.h"
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#include "dv.h"
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//#define DEBUG
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//#define DEBUG_SEEK
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typedef struct AVIIndexEntry {
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unsigned int flags;
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unsigned int pos;
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unsigned int cum_len; /* sum of all lengths before this packet */
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} AVIIndexEntry;
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typedef struct AVIStream {
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AVIIndexEntry *index_entries;
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int nb_index_entries;
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int index_entries_allocated_size;
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int frame_offset; /* current frame (video) or byte (audio) counter
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(used to compute the pts) */
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int scale;
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int rate;
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int sample_size; /* audio only data */
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int new_frame_offset; /* temporary storage (used during seek) */
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int cum_len; /* temporary storage (used during seek) */
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} AVIStream;
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typedef struct {
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int64_t riff_end;
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int64_t movi_end;
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offset_t movi_list;
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int index_loaded;
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DVDemuxContext* dv_demux;
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} AVIContext;
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#ifdef DEBUG
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static void print_tag(const char *str, unsigned int tag, int size)
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{
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printf("%s: tag=%c%c%c%c size=0x%x\n",
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str, tag & 0xff,
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(tag >> 8) & 0xff,
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(tag >> 16) & 0xff,
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(tag >> 24) & 0xff,
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size);
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}
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#endif
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static int get_riff(AVIContext *avi, ByteIOContext *pb)
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{
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uint32_t tag;
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/* check RIFF header */
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tag = get_le32(pb);
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if (tag != MKTAG('R', 'I', 'F', 'F'))
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return -1;
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avi->riff_end = get_le32(pb); /* RIFF chunk size */
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avi->riff_end += url_ftell(pb); /* RIFF chunk end */
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tag = get_le32(pb);
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if (tag != MKTAG('A', 'V', 'I', ' ') && tag != MKTAG('A', 'V', 'I', 'X'))
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return -1;
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return 0;
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}
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static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
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{
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AVIContext *avi = s->priv_data;
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ByteIOContext *pb = &s->pb;
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uint32_t tag, tag1, handler;
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int codec_type, stream_index, frame_period, bit_rate, scale, rate;
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unsigned int size, nb_frames;
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int i, n;
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AVStream *st;
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AVIStream *ast;
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int xan_video = 0; /* hack to support Xan A/V */
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av_set_pts_info(s, 64, 1, AV_TIME_BASE);
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if (get_riff(avi, pb) < 0)
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return -1;
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/* first list tag */
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stream_index = -1;
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codec_type = -1;
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frame_period = 0;
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for(;;) {
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if (url_feof(pb))
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goto fail;
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tag = get_le32(pb);
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size = get_le32(pb);
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#ifdef DEBUG
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print_tag("tag", tag, size);
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#endif
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switch(tag) {
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case MKTAG('L', 'I', 'S', 'T'):
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/* ignored, except when start of video packets */
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tag1 = get_le32(pb);
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#ifdef DEBUG
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print_tag("list", tag1, 0);
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#endif
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if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
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avi->movi_list = url_ftell(pb) - 4;
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avi->movi_end = avi->movi_list + size;
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#ifdef DEBUG
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printf("movi end=%Lx\n", avi->movi_end);
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#endif
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goto end_of_header;
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}
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break;
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case MKTAG('a', 'v', 'i', 'h'):
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/* avi header */
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/* using frame_period is bad idea */
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frame_period = get_le32(pb);
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bit_rate = get_le32(pb) * 8;
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url_fskip(pb, 4 * 4);
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n = get_le32(pb);
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for(i=0;i<n;i++) {
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AVIStream *ast;
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st = av_new_stream(s, i);
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if (!st)
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goto fail;
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ast = av_mallocz(sizeof(AVIStream));
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if (!ast)
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goto fail;
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st->priv_data = ast;
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}
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url_fskip(pb, size - 7 * 4);
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break;
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case MKTAG('s', 't', 'r', 'h'):
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/* stream header */
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stream_index++;
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tag1 = get_le32(pb);
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handler = get_le32(pb); /* codec tag */
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switch(tag1) {
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case MKTAG('i', 'a', 'v', 's'):
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case MKTAG('i', 'v', 'a', 's'):
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/*
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* After some consideration -- I don't think we
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* have to support anything but DV in a type1 AVIs.
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*/
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if (s->nb_streams != 1)
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goto fail;
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if (handler != MKTAG('d', 'v', 's', 'd') &&
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handler != MKTAG('d', 'v', 'h', 'd') &&
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handler != MKTAG('d', 'v', 's', 'l'))
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goto fail;
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av_freep(&s->streams[0]->codec.extradata);
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av_freep(&s->streams[0]);
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s->nb_streams = 0;
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avi->dv_demux = dv_init_demux(s);
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if (!avi->dv_demux)
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goto fail;
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stream_index = s->nb_streams - 1;
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url_fskip(pb, size - 8);
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break;
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case MKTAG('v', 'i', 'd', 's'):
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codec_type = CODEC_TYPE_VIDEO;
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if (stream_index >= s->nb_streams) {
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url_fskip(pb, size - 8);
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break;
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}
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st = s->streams[stream_index];
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ast = st->priv_data;
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st->codec.stream_codec_tag= handler;
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get_le32(pb); /* flags */
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get_le16(pb); /* priority */
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get_le16(pb); /* language */
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get_le32(pb); /* XXX: initial frame ? */
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scale = get_le32(pb); /* scale */
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rate = get_le32(pb); /* rate */
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if(scale && rate){
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}else if(frame_period){
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rate = 1000000;
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scale = frame_period;
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}else{
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rate = 25;
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scale = 1;
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}
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ast->rate = rate;
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ast->scale = scale;
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st->codec.frame_rate = rate;
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st->codec.frame_rate_base = scale;
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get_le32(pb); /* start */
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nb_frames = get_le32(pb);
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st->start_time = 0;
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st->duration = (double)nb_frames *
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st->codec.frame_rate_base * AV_TIME_BASE /
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st->codec.frame_rate;
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url_fskip(pb, size - 9 * 4);
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break;
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case MKTAG('a', 'u', 'd', 's'):
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{
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unsigned int length;
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codec_type = CODEC_TYPE_AUDIO;
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if (stream_index >= s->nb_streams) {
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url_fskip(pb, size - 8);
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break;
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}
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st = s->streams[stream_index];
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ast = st->priv_data;
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get_le32(pb); /* flags */
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get_le16(pb); /* priority */
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get_le16(pb); /* language */
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get_le32(pb); /* initial frame */
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ast->scale = get_le32(pb); /* scale */
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ast->rate = get_le32(pb);
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get_le32(pb); /* start */
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length = get_le32(pb); /* length, in samples or bytes */
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get_le32(pb); /* buffer size */
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get_le32(pb); /* quality */
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ast->sample_size = get_le32(pb); /* sample ssize */
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st->start_time = 0;
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if (ast->rate != 0)
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st->duration = (int64_t)length * AV_TIME_BASE / ast->rate;
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url_fskip(pb, size - 12 * 4);
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}
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break;
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default:
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goto fail;
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}
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break;
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case MKTAG('s', 't', 'r', 'f'):
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/* stream header */
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if (stream_index >= s->nb_streams || avi->dv_demux) {
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url_fskip(pb, size);
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} else {
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st = s->streams[stream_index];
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switch(codec_type) {
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case CODEC_TYPE_VIDEO:
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get_le32(pb); /* size */
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st->codec.width = get_le32(pb);
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st->codec.height = get_le32(pb);
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get_le16(pb); /* panes */
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st->codec.bits_per_sample= get_le16(pb); /* depth */
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tag1 = get_le32(pb);
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get_le32(pb); /* ImageSize */
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get_le32(pb); /* XPelsPerMeter */
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get_le32(pb); /* YPelsPerMeter */
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get_le32(pb); /* ClrUsed */
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get_le32(pb); /* ClrImportant */
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st->codec.extradata_size= size - 10*4;
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st->codec.extradata= av_malloc(st->codec.extradata_size);
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get_buffer(pb, st->codec.extradata, st->codec.extradata_size);
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if(st->codec.extradata_size & 1) //FIXME check if the encoder really did this correctly
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get_byte(pb);
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/* Extract palette from extradata if bpp <= 8 */
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/* This code assumes that extradata contains only palette */
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/* This is true for all paletted codecs implemented in ffmpeg */
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if (st->codec.extradata_size && (st->codec.bits_per_sample <= 8)) {
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st->codec.palctrl = av_mallocz(sizeof(AVPaletteControl));
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#ifdef WORDS_BIGENDIAN
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for (i = 0; i < FFMIN(st->codec.extradata_size, AVPALETTE_SIZE)/4; i++)
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st->codec.palctrl->palette[i] = bswap_32(((uint32_t*)st->codec.extradata)[i]);
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#else
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memcpy(st->codec.palctrl->palette, st->codec.extradata,
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FFMIN(st->codec.extradata_size, AVPALETTE_SIZE));
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#endif
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st->codec.palctrl->palette_changed = 1;
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}
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#ifdef DEBUG
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print_tag("video", tag1, 0);
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#endif
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st->codec.codec_type = CODEC_TYPE_VIDEO;
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st->codec.codec_tag = tag1;
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st->codec.codec_id = codec_get_id(codec_bmp_tags, tag1);
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if (st->codec.codec_id == CODEC_ID_XAN_WC4)
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xan_video = 1;
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// url_fskip(pb, size - 5 * 4);
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break;
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case CODEC_TYPE_AUDIO:
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get_wav_header(pb, &st->codec, size);
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if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
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url_fskip(pb, 1);
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/* special case time: To support Xan DPCM, hardcode
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* the format if Xxan is the video codec */
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st->need_parsing = 1;
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/* force parsing as several audio frames can be in
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one packet */
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if (xan_video)
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st->codec.codec_id = CODEC_ID_XAN_DPCM;
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break;
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default:
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url_fskip(pb, size);
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break;
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}
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}
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break;
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default:
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/* skip tag */
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size += (size & 1);
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url_fskip(pb, size);
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break;
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}
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}
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end_of_header:
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/* check stream number */
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if (stream_index != s->nb_streams - 1) {
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fail:
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for(i=0;i<s->nb_streams;i++) {
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av_freep(&s->streams[i]->codec.extradata);
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av_freep(&s->streams[i]);
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}
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return -1;
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}
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return 0;
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}
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static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
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{
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AVIContext *avi = s->priv_data;
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ByteIOContext *pb = &s->pb;
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int n, d[8], size, i;
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void* dstr;
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memset(d, -1, sizeof(int)*8);
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if (avi->dv_demux) {
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size = dv_get_packet(avi->dv_demux, pkt);
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if (size >= 0)
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return size;
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}
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for(i=url_ftell(pb); !url_feof(pb); i++) {
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int j;
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if (i >= avi->movi_end) { /* Let's see if it's an OpenDML AVI */
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uint32_t tag, size, tag2;
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url_fskip(pb, avi->riff_end - url_ftell(pb));
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if (get_riff(avi, pb) < 0)
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return -1;
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tag = get_le32(pb);
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size = get_le32(pb);
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tag2 = get_le32(pb);
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if (tag == MKTAG('L','I','S','T') && tag2 == MKTAG('m','o','v','i'))
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avi->movi_end = url_ftell(pb) + size - 4;
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else
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return -1;
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}
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for(j=0; j<7; j++)
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d[j]= d[j+1];
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d[7]= get_byte(pb);
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size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
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//parse ix##
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n= (d[2] - '0') * 10 + (d[3] - '0');
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if( d[2] >= '0' && d[2] <= '9'
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&& d[3] >= '0' && d[3] <= '9'
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&& d[0] == 'i' && d[1] == 'x'
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&& n < s->nb_streams
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&& i + size <= avi->movi_end){
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url_fskip(pb, size);
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}
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//parse ##dc/##wb
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n= (d[0] - '0') * 10 + (d[1] - '0');
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if( d[0] >= '0' && d[0] <= '9'
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&& d[1] >= '0' && d[1] <= '9'
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&& ((d[2] == 'd' && d[3] == 'c') ||
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(d[2] == 'w' && d[3] == 'b') ||
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(d[2] == 'd' && d[3] == 'b') ||
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(d[2] == '_' && d[3] == '_'))
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&& n < s->nb_streams
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&& i + size <= avi->movi_end) {
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av_new_packet(pkt, size);
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get_buffer(pb, pkt->data, size);
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if (size & 1) {
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get_byte(pb);
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size++;
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}
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if (avi->dv_demux) {
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dstr = pkt->destruct;
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size = dv_produce_packet(avi->dv_demux, pkt,
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pkt->data, pkt->size);
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pkt->destruct = dstr;
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pkt->flags |= PKT_FLAG_KEY;
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} else {
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AVStream *st;
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AVIStream *ast;
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st = s->streams[n];
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ast = st->priv_data;
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/* XXX: how to handle B frames in avi ? */
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pkt->pts = ((int64_t)ast->frame_offset * ast->scale* AV_TIME_BASE) / ast->rate;
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pkt->stream_index = n;
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/* FIXME: We really should read index for that */
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if (st->codec.codec_type == CODEC_TYPE_VIDEO) {
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if (ast->frame_offset < ast->nb_index_entries) {
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if (ast->index_entries[ast->frame_offset].flags & AVIIF_INDEX)
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pkt->flags |= PKT_FLAG_KEY;
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} else {
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/* if no index, better to say that all frames
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are key frames */
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pkt->flags |= PKT_FLAG_KEY;
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}
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ast->frame_offset++;
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} else {
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ast->frame_offset += pkt->size;
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pkt->flags |= PKT_FLAG_KEY;
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}
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}
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return size;
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}
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}
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return -1;
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}
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/* XXX: we make the implicit supposition that the position are sorted
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for each stream */
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static int avi_read_idx1(AVFormatContext *s, int size)
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{
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ByteIOContext *pb = &s->pb;
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int nb_index_entries, i;
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AVStream *st;
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AVIStream *ast;
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AVIIndexEntry *ie, *entries;
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unsigned int index, tag, flags, pos, len;
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nb_index_entries = size / 16;
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if (nb_index_entries <= 0)
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return -1;
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/* read the entries and sort them in each stream component */
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for(i = 0; i < nb_index_entries; i++) {
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tag = get_le32(pb);
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flags = get_le32(pb);
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pos = get_le32(pb);
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len = get_le32(pb);
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#if defined(DEBUG_SEEK) && 0
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printf("%d: tag=0x%x flags=0x%x pos=0x%x len=%d\n",
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i, tag, flags, pos, len);
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#endif
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index = ((tag & 0xff) - '0') * 10;
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index += ((tag >> 8) & 0xff) - '0';
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if (index >= s->nb_streams)
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continue;
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st = s->streams[index];
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ast = st->priv_data;
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entries = av_fast_realloc(ast->index_entries,
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&ast->index_entries_allocated_size,
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(ast->nb_index_entries + 1) *
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sizeof(AVIIndexEntry));
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if (entries) {
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ast->index_entries = entries;
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ie = &entries[ast->nb_index_entries++];
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ie->flags = flags;
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ie->pos = pos;
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ie->cum_len = ast->cum_len;
|
|
ast->cum_len += len;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int avi_load_index(AVFormatContext *s)
|
|
{
|
|
AVIContext *avi = s->priv_data;
|
|
ByteIOContext *pb = &s->pb;
|
|
uint32_t tag, size;
|
|
|
|
url_fseek(pb, avi->movi_end, SEEK_SET);
|
|
#ifdef DEBUG_SEEK
|
|
printf("movi_end=0x%llx\n", avi->movi_end);
|
|
#endif
|
|
for(;;) {
|
|
if (url_feof(pb))
|
|
break;
|
|
tag = get_le32(pb);
|
|
size = get_le32(pb);
|
|
#ifdef DEBUG_SEEK
|
|
printf("tag=%c%c%c%c size=0x%x\n",
|
|
tag & 0xff,
|
|
(tag >> 8) & 0xff,
|
|
(tag >> 16) & 0xff,
|
|
(tag >> 24) & 0xff,
|
|
size);
|
|
#endif
|
|
switch(tag) {
|
|
case MKTAG('i', 'd', 'x', '1'):
|
|
if (avi_read_idx1(s, size) < 0)
|
|
goto skip;
|
|
else
|
|
goto the_end;
|
|
break;
|
|
default:
|
|
skip:
|
|
size += (size & 1);
|
|
url_fskip(pb, size);
|
|
break;
|
|
}
|
|
}
|
|
the_end:
|
|
return 0;
|
|
}
|
|
|
|
/* return the index entry whose position is immediately >= 'wanted_pos' */
|
|
static int locate_frame_in_index(AVIIndexEntry *entries,
|
|
int nb_entries, int wanted_pos)
|
|
{
|
|
int a, b, m, pos;
|
|
|
|
a = 0;
|
|
b = nb_entries - 1;
|
|
while (a <= b) {
|
|
m = (a + b) >> 1;
|
|
pos = entries[m].pos;
|
|
if (pos == wanted_pos)
|
|
goto found;
|
|
else if (pos > wanted_pos) {
|
|
b = m - 1;
|
|
} else {
|
|
a = m + 1;
|
|
}
|
|
}
|
|
m = a;
|
|
if (m > 0)
|
|
m--;
|
|
found:
|
|
return m;
|
|
}
|
|
|
|
static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp)
|
|
{
|
|
AVIContext *avi = s->priv_data;
|
|
AVStream *st;
|
|
AVIStream *ast;
|
|
int frame_number, i;
|
|
int64_t pos;
|
|
|
|
if (!avi->index_loaded) {
|
|
/* we only load the index on demand */
|
|
avi_load_index(s);
|
|
avi->index_loaded = 1;
|
|
}
|
|
if (stream_index < 0) {
|
|
for(i = 0; i < s->nb_streams; i++) {
|
|
st = s->streams[i];
|
|
if (st->codec.codec_type == CODEC_TYPE_VIDEO)
|
|
goto found;
|
|
}
|
|
return -1;
|
|
found:
|
|
stream_index = i;
|
|
}
|
|
|
|
st = s->streams[stream_index];
|
|
if (st->codec.codec_type != CODEC_TYPE_VIDEO)
|
|
return -1;
|
|
ast = st->priv_data;
|
|
/* compute the frame number */
|
|
frame_number = (timestamp * ast->rate) /
|
|
(ast->scale * (int64_t)AV_TIME_BASE);
|
|
#ifdef DEBUG_SEEK
|
|
printf("timestamp=%0.3f nb_indexes=%d frame_number=%d\n",
|
|
(double)timestamp / AV_TIME_BASE,
|
|
ast->nb_index_entries, frame_number);
|
|
#endif
|
|
/* find a closest key frame before */
|
|
if (frame_number >= ast->nb_index_entries)
|
|
return -1;
|
|
while (frame_number >= 0 &&
|
|
!(ast->index_entries[frame_number].flags & AVIIF_INDEX))
|
|
frame_number--;
|
|
if (frame_number < 0)
|
|
return -1;
|
|
ast->new_frame_offset = frame_number;
|
|
|
|
/* find the position */
|
|
pos = ast->index_entries[frame_number].pos;
|
|
|
|
#ifdef DEBUG_SEEK
|
|
printf("key_frame_number=%d pos=0x%llx\n",
|
|
frame_number, pos);
|
|
#endif
|
|
|
|
/* update the frame counters for all the other stream by looking
|
|
at the positions just after the one found */
|
|
for(i = 0; i < s->nb_streams; i++) {
|
|
int j;
|
|
if (i != stream_index) {
|
|
st = s->streams[i];
|
|
ast = st->priv_data;
|
|
if (ast->nb_index_entries <= 0)
|
|
return -1;
|
|
j = locate_frame_in_index(ast->index_entries,
|
|
ast->nb_index_entries,
|
|
pos);
|
|
/* get next frame */
|
|
if ((j + 1) < ast->nb_index_entries)
|
|
j++;
|
|
/* extract the current frame number */
|
|
if (st->codec.codec_type == CODEC_TYPE_VIDEO)
|
|
ast->new_frame_offset = j;
|
|
else
|
|
ast->new_frame_offset = ast->index_entries[j].cum_len;
|
|
}
|
|
}
|
|
|
|
/* everything is OK now. We can update the frame offsets */
|
|
for(i = 0; i < s->nb_streams; i++) {
|
|
st = s->streams[i];
|
|
ast = st->priv_data;
|
|
ast->frame_offset = ast->new_frame_offset;
|
|
#ifdef DEBUG_SEEK
|
|
printf("%d: frame_offset=%d\n", i,
|
|
ast->frame_offset);
|
|
#endif
|
|
}
|
|
/* do the seek */
|
|
pos += avi->movi_list;
|
|
url_fseek(&s->pb, pos, SEEK_SET);
|
|
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){
|
|
av_free(ast->index_entries);
|
|
av_free(ast);
|
|
}
|
|
av_free(st->codec.extradata);
|
|
av_free(st->codec.palctrl);
|
|
}
|
|
|
|
if (avi->dv_demux)
|
|
av_free(avi->dv_demux);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int avi_probe(AVProbeData *p)
|
|
{
|
|
/* check file header */
|
|
if (p->buf_size <= 32)
|
|
return 0;
|
|
if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
|
|
p->buf[2] == 'F' && p->buf[3] == 'F' &&
|
|
p->buf[8] == 'A' && p->buf[9] == 'V' &&
|
|
p->buf[10] == 'I' && p->buf[11] == ' ')
|
|
return AVPROBE_SCORE_MAX;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
static AVInputFormat avi_iformat = {
|
|
"avi",
|
|
"avi format",
|
|
sizeof(AVIContext),
|
|
avi_probe,
|
|
avi_read_header,
|
|
avi_read_packet,
|
|
avi_read_close,
|
|
avi_read_seek,
|
|
};
|
|
|
|
int avidec_init(void)
|
|
{
|
|
av_register_input_format(&avi_iformat);
|
|
return 0;
|
|
}
|