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5e6ce28dab
"Fast seek" uses linear interpolation to find the position of the requested seek time. For CBR this is more direct than using the mp3 TOC and bypassing the TOC avoids problems with TOC precision. (see https://crbug.com/545914#c13) For VBR, fast seek is not precise, so continue to prefer the TOC when available (the lesser of two evils). Also, some re-ordering of the logic in mp3_seek to simplify and give usetoc=1 precedence over fastseek flag. Signed-off-by: wm4 <nfxjfg@googlemail.com>
159 lines
5.0 KiB
C
159 lines
5.0 KiB
C
/*
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* Copyright (c) 2003 Fabrice Bellard
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* Copyright (c) 2007 Michael Niedermayer
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg 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 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg 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 FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <stdint.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include "libavutil/common.h"
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#include "libavutil/mathematics.h"
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#include "libavformat/avformat.h"
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static char buffer[20];
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static const char *ret_str(int v)
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{
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switch (v) {
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case AVERROR_EOF: return "-EOF";
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case AVERROR(EIO): return "-EIO";
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case AVERROR(ENOMEM): return "-ENOMEM";
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case AVERROR(EINVAL): return "-EINVAL";
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default:
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snprintf(buffer, sizeof(buffer), "%2d", v);
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return buffer;
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}
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}
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static void ts_str(char buffer[60], int64_t ts, AVRational base)
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{
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if (ts == AV_NOPTS_VALUE) {
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strcpy(buffer, " NOPTS ");
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return;
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}
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ts= av_rescale_q(ts, base, (AVRational){1, 1000000});
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snprintf(buffer, 60, "%c%"PRId64".%06"PRId64"", ts<0 ? '-' : ' ', FFABS(ts)/1000000, FFABS(ts)%1000000);
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}
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int main(int argc, char **argv)
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{
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const char *filename;
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AVFormatContext *ic = avformat_alloc_context();
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int i, ret, stream_id;
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int j;
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int64_t timestamp;
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AVDictionary *format_opts = NULL;
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int64_t seekfirst = AV_NOPTS_VALUE;
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int firstback=0;
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int frame_count = 1;
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int duration = 4;
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for(i=2; i<argc; i+=2){
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if (!strcmp(argv[i], "-seekforw")){
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seekfirst = atoi(argv[i+1]);
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} else if(!strcmp(argv[i], "-seekback")){
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seekfirst = atoi(argv[i+1]);
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firstback = 1;
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} else if(!strcmp(argv[i], "-frames")){
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frame_count = atoi(argv[i+1]);
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} else if(!strcmp(argv[i], "-duration")){
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duration = atoi(argv[i+1]);
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} else if(!strcmp(argv[i], "-fastseek")) {
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if (atoi(argv[i+1])) {
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ic->flags |= AVFMT_FLAG_FAST_SEEK;
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}
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} else {
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argc = 1;
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}
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}
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av_dict_set(&format_opts, "channels", "1", 0);
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av_dict_set(&format_opts, "sample_rate", "22050", 0);
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/* initialize libavcodec, and register all codecs and formats */
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av_register_all();
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if (argc < 2) {
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printf("usage: %s input_file\n"
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"\n", argv[0]);
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return 1;
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}
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filename = argv[1];
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ret = avformat_open_input(&ic, filename, NULL, &format_opts);
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av_dict_free(&format_opts);
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if (ret < 0) {
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fprintf(stderr, "cannot open %s\n", filename);
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return 1;
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}
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ret = avformat_find_stream_info(ic, NULL);
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if (ret < 0) {
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fprintf(stderr, "%s: could not find codec parameters\n", filename);
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return 1;
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}
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if(seekfirst != AV_NOPTS_VALUE){
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if(firstback) avformat_seek_file(ic, -1, INT64_MIN, seekfirst, seekfirst, 0);
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else avformat_seek_file(ic, -1, seekfirst, seekfirst, INT64_MAX, 0);
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}
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for(i=0; ; i++){
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AVPacket pkt = { 0 };
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AVStream *av_uninit(st);
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char ts_buf[60];
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if(ret>=0){
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for(j=0; j<frame_count; j++) {
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ret= av_read_frame(ic, &pkt);
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if(ret>=0){
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char dts_buf[60];
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st= ic->streams[pkt.stream_index];
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ts_str(dts_buf, pkt.dts, st->time_base);
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ts_str(ts_buf, pkt.pts, st->time_base);
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printf("ret:%-10s st:%2d flags:%d dts:%s pts:%s pos:%7" PRId64 " size:%6d", ret_str(ret), pkt.stream_index, pkt.flags, dts_buf, ts_buf, pkt.pos, pkt.size);
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av_packet_unref(&pkt);
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} else
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printf("ret:%s", ret_str(ret)); // necessary to avoid trailing whitespace
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printf("\n");
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}
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}
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if(i>25) break;
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stream_id= (i>>1)%(ic->nb_streams+1) - 1;
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timestamp= (i*19362894167LL) % (duration*AV_TIME_BASE) - AV_TIME_BASE;
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if(stream_id>=0){
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st= ic->streams[stream_id];
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timestamp= av_rescale_q(timestamp, AV_TIME_BASE_Q, st->time_base);
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}
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//FIXME fully test the new seek API
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if(i&1) ret = avformat_seek_file(ic, stream_id, INT64_MIN, timestamp, timestamp, 0);
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else ret = avformat_seek_file(ic, stream_id, timestamp, timestamp, INT64_MAX, 0);
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ts_str(ts_buf, timestamp, stream_id < 0 ? AV_TIME_BASE_Q : st->time_base);
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printf("ret:%-10s st:%2d flags:%d ts:%s\n", ret_str(ret), stream_id, i&1, ts_buf);
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}
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avformat_close_input(&ic);
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return 0;
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}
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