mirror of
https://github.com/ZLMediaKit/ZLMediaKit.git
synced 2024-11-23 19:20:53 +08:00
99 lines
3.0 KiB
C++
99 lines
3.0 KiB
C++
/*
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* MIT License
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*
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* Copyright (c) 2016-2019 xiongziliang <771730766@qq.com>
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*
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* This file is part of ZLMediaKit(https://github.com/xiongziliang/ZLMediaKit).
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include "Stamp.h"
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#define MAX_DELTA_STAMP 300
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namespace mediakit {
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int64_t DeltaStamp::deltaStamp(int64_t stamp) {
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if(!_last_stamp){
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//第一次计算时间戳增量,时间戳增量为0
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_last_stamp = stamp;
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return 0;
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}
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int64_t ret = stamp - _last_stamp;
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if(ret >= 0){
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//时间戳增量为正，返回之
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_last_stamp = stamp;
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//在直播情况下，时间戳增量不得大于MAX_DELTA_STAMP
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return ret < MAX_DELTA_STAMP ? ret : (_playback ? ret : 0);
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}
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//时间戳增量为负，说明时间戳回环了或回退了
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_last_stamp = stamp;
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return _playback ? ret : 0;
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}
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void DeltaStamp::setPlayBack(bool playback) {
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_playback = playback;
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}
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void Stamp::revise(int64_t dts, int64_t pts, int64_t &dts_out, int64_t &pts_out,bool modifyStamp) {
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if(!pts){
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//没有播放时间戳,使其赋值为解码时间戳
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pts = dts;
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}
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//pts和dts的差值
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int pts_dts_diff = pts - dts;
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if(_last_dts != dts){
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//时间戳发生变更
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if(modifyStamp){
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_relativeStamp = _ticker.elapsedTime();
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}else{
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_relativeStamp += deltaStamp(dts);
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}
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_last_dts = dts;
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}
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dts_out = _relativeStamp;
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//////////////以下是播放时间戳的计算//////////////////
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if(pts_dts_diff > MAX_DELTA_STAMP || pts_dts_diff < -MAX_DELTA_STAMP){
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//如果差值太大，则认为由于回环导致时间戳错乱了
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pts_dts_diff = 0;
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}
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pts_out = dts_out + pts_dts_diff;
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if(pts_out < 0){
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//时间戳不能小于0
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pts_out = 0;
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}
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}
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void Stamp::setRelativeStamp(int64_t relativeStamp) {
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_relativeStamp = relativeStamp;
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}
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int64_t Stamp::getRelativeStamp() const {
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return _relativeStamp;
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}
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}//namespace mediakit
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