/* * Copyright (c) 2016 The ZLMediaKit project authors. All Rights Reserved. * * This file is part of ZLMediaKit(https://github.com/xia-chu/ZLMediaKit). * * Use of this source code is governed by MIT license that can be found in the * LICENSE file in the root of the source tree. All contributing project authors * may be found in the AUTHORS file in the root of the source tree. */ #include #include "Util/util.h" #include "Util/NoticeCenter.h" #include "Network/sockutil.h" #include "Network/Session.h" #include "MediaSource.h" #include "Common/config.h" #include "Common/Parser.h" #include "Record/MP4Reader.h" #include "PacketCache.h" using namespace std; using namespace toolkit; namespace toolkit { StatisticImp(mediakit::MediaSource); } namespace mediakit { static recursive_mutex s_media_source_mtx; using StreamMap = unordered_map >; using AppStreamMap = unordered_map; using VhostAppStreamMap = unordered_map; using SchemaVhostAppStreamMap = unordered_map; static SchemaVhostAppStreamMap s_media_source_map; string getOriginTypeString(MediaOriginType type){ #define SWITCH_CASE(type) case MediaOriginType::type : return #type switch (type) { SWITCH_CASE(unknown); SWITCH_CASE(rtmp_push); SWITCH_CASE(rtsp_push); SWITCH_CASE(rtp_push); SWITCH_CASE(pull); SWITCH_CASE(ffmpeg_pull); SWITCH_CASE(mp4_vod); SWITCH_CASE(device_chn); SWITCH_CASE(rtc_push); SWITCH_CASE(srt_push); default : return "unknown"; } } ////////////////////////////////////////////////////////////////////////////////////////////////////////////// ProtocolOption::ProtocolOption() { GET_CONFIG(bool, s_modify_stamp, Protocol::kModifyStamp); GET_CONFIG(bool, s_enabel_audio, Protocol::kEnableAudio); GET_CONFIG(bool, s_add_mute_audio, Protocol::kAddMuteAudio); GET_CONFIG(uint32_t, s_continue_push_ms, Protocol::kContinuePushMS); GET_CONFIG(bool, s_enable_hls, Protocol::kEnableHls); GET_CONFIG(bool, s_enable_mp4, Protocol::kEnableMP4); GET_CONFIG(bool, s_enable_rtsp, Protocol::kEnableRtsp); GET_CONFIG(bool, s_enable_rtmp, Protocol::kEnableRtmp); GET_CONFIG(bool, s_enable_ts, Protocol::kEnableTS); GET_CONFIG(bool, s_enable_fmp4, Protocol::kEnableFMP4); GET_CONFIG(bool, s_hls_demand, Protocol::kHlsDemand); GET_CONFIG(bool, s_rtsp_demand, Protocol::kRtspDemand); GET_CONFIG(bool, s_rtmp_demand, Protocol::kRtmpDemand); GET_CONFIG(bool, s_ts_demand, Protocol::kTSDemand); GET_CONFIG(bool, s_fmp4_demand, Protocol::kFMP4Demand); GET_CONFIG(bool, s_mp4_as_player, Protocol::kMP4AsPlayer); GET_CONFIG(uint32_t, s_mp4_max_second, Protocol::kMP4MaxSecond); GET_CONFIG(string, s_mp4_save_path, Protocol::kMP4SavePath); GET_CONFIG(string, s_hls_save_path, Protocol::kHlsSavePath); modify_stamp = s_modify_stamp; enable_audio = s_enabel_audio; add_mute_audio = s_add_mute_audio; continue_push_ms = s_continue_push_ms; enable_hls = s_enable_hls; enable_mp4 = s_enable_mp4; enable_rtsp = s_enable_rtsp; enable_rtmp = s_enable_rtmp; enable_ts = s_enable_ts; enable_fmp4 = s_enable_fmp4; hls_demand = s_hls_demand; rtsp_demand = s_rtsp_demand; rtmp_demand = s_rtmp_demand; ts_demand = s_ts_demand; fmp4_demand = s_fmp4_demand; mp4_as_player = s_mp4_as_player; mp4_max_second = s_mp4_max_second; mp4_save_path = s_mp4_save_path; hls_save_path = s_hls_save_path; } ////////////////////////////////////////////////////////////////////////////////////////////////////////////// struct MediaSourceNull : public MediaSource { MediaSourceNull() : MediaSource("schema", MediaTuple{"vhost", "app", "stream"}) {}; int readerCount() override { return 0; } }; MediaSource &MediaSource::NullMediaSource() { static std::shared_ptr s_null = std::make_shared(); return *s_null; } MediaSource::MediaSource(const string &schema, const MediaTuple& tuple): _tuple(tuple) { GET_CONFIG(bool, enableVhost, General::kEnableVhost); if (!enableVhost || _tuple.vhost.empty()) { _tuple.vhost = DEFAULT_VHOST; } _schema = schema; _create_stamp = time(NULL); } MediaSource::~MediaSource() { unregist(); } const string& MediaSource::getSchema() const { return _schema; } const string& MediaSource::getVhost() const { return _tuple.vhost; } const string& MediaSource::getApp() const { //获取该源的id return _tuple.app; } const string& MediaSource::getId() const { return _tuple.stream; } std::shared_ptr MediaSource::getOwnership() { if (_owned.test_and_set()) { //已经被所有 return nullptr; } weak_ptr weak_self = shared_from_this(); //确保返回的Ownership智能指针不为空,0x01无实际意义 return std::shared_ptr((void *) 0x01, [weak_self](void *ptr) { auto strong_self = weak_self.lock(); if (strong_self) { strong_self->_owned.clear(); } }); } int MediaSource::getBytesSpeed(TrackType type){ if(type == TrackInvalid || type == TrackMax){ return _speed[TrackVideo].getSpeed() + _speed[TrackAudio].getSpeed(); } return _speed[type].getSpeed(); } uint64_t MediaSource::getAliveSecond() const { //使用Ticker对象获取存活时间的目的是防止修改系统时间导致回退 return _ticker.createdTime() / 1000; } vector MediaSource::getTracks(bool ready) const { auto listener = _listener.lock(); if(!listener){ return vector(); } return listener->getMediaTracks(const_cast(*this), ready); } void MediaSource::setListener(const std::weak_ptr &listener){ _listener = listener; } std::weak_ptr MediaSource::getListener(bool next) const{ if (!next) { return _listener; } auto listener = dynamic_pointer_cast(_listener.lock()); if (!listener) { //不是MediaSourceEventInterceptor对象或者对象已经销毁 return _listener; } //获取被拦截的对象 auto next_obj = listener->getDelegate(); //有则返回之 return next_obj ? next_obj : _listener; } int MediaSource::totalReaderCount(){ auto listener = _listener.lock(); if(!listener){ return readerCount(); } return listener->totalReaderCount(*this); } MediaOriginType MediaSource::getOriginType() const { auto listener = _listener.lock(); if (!listener) { return MediaOriginType::unknown; } return listener->getOriginType(const_cast(*this)); } string MediaSource::getOriginUrl() const { auto listener = _listener.lock(); if (!listener) { return getUrl(); } auto ret = listener->getOriginUrl(const_cast(*this)); if (!ret.empty()) { return ret; } return getUrl(); } std::shared_ptr MediaSource::getOriginSock() const { auto listener = _listener.lock(); if (!listener) { return nullptr; } return listener->getOriginSock(const_cast(*this)); } bool MediaSource::seekTo(uint32_t stamp) { auto listener = _listener.lock(); if(!listener){ return false; } return listener->seekTo(*this, stamp); } bool MediaSource::pause(bool pause) { auto listener = _listener.lock(); if (!listener) { return false; } return listener->pause(*this, pause); } bool MediaSource::speed(float speed) { auto listener = _listener.lock(); if (!listener) { return false; } return listener->speed(*this, speed); } bool MediaSource::close(bool force) { auto listener = _listener.lock(); if (!listener) { return false; } if (!force && totalReaderCount()) { //有人观看,不强制关闭 return false; } return listener->close(*this); } float MediaSource::getLossRate(mediakit::TrackType type) { auto listener = _listener.lock(); if (!listener) { return -1; } return listener->getLossRate(*this, type); } toolkit::EventPoller::Ptr MediaSource::getOwnerPoller() { toolkit::EventPoller::Ptr ret; auto listener = _listener.lock(); if (listener) { return listener->getOwnerPoller(*this); } throw std::runtime_error(toolkit::demangle(typeid(*this).name()) + "::getOwnerPoller failed: " + getUrl()); } void MediaSource::onReaderChanged(int size) { try { weak_ptr weak_self = shared_from_this(); getOwnerPoller()->async([weak_self, size]() { auto strong_self = weak_self.lock(); if (!strong_self) { return; } auto listener = strong_self->_listener.lock(); if (listener) { listener->onReaderChanged(*strong_self, size); } }); } catch (MediaSourceEvent::NotImplemented &ex) { // 未实现接口,应该打印异常 WarnL << ex.what(); } catch (...) { // getOwnerPoller()接口抛异常机制应该只对外不对内 // 所以listener已经销毁导致获取归属线程失败的异常直接忽略 } } bool MediaSource::setupRecord(Recorder::type type, bool start, const string &custom_path, size_t max_second){ auto listener = _listener.lock(); if (!listener) { WarnL << "未设置MediaSource的事件监听者,setupRecord失败:" << getUrl(); return false; } return listener->setupRecord(*this, type, start, custom_path, max_second); } bool MediaSource::isRecording(Recorder::type type){ auto listener = _listener.lock(); if(!listener){ return false; } return listener->isRecording(*this, type); } void MediaSource::startSendRtp(const MediaSourceEvent::SendRtpArgs &args, const std::function cb) { auto listener = _listener.lock(); if (!listener) { cb(0, SockException(Err_other, "尚未设置事件监听器")); return; } return listener->startSendRtp(*this, args, cb); } bool MediaSource::stopSendRtp(const string &ssrc) { auto listener = _listener.lock(); if (!listener) { return false; } return listener->stopSendRtp(*this, ssrc); } template static void for_each_media_l(const MAP &map, LIST &list, const First &first, const KeyTypes &...keys) { if (first.empty()) { for (auto &pr : map) { for_each_media_l(pr.second, list, keys...); } return; } auto it = map.find(first); if (it != map.end()) { for_each_media_l(it->second, list, keys...); } } template static void emplace_back(LIST &list, const Ptr &ptr) { auto src = ptr.lock(); if (src) { list.emplace_back(std::move(src)); } } template static void for_each_media_l(const MAP &map, LIST &list, const First &first) { if (first.empty()) { for (auto &pr : map) { emplace_back(list, pr.second); } return; } auto it = map.find(first); if (it != map.end()) { emplace_back(list, it->second); } } void MediaSource::for_each_media(const function &cb, const string &schema, const string &vhost, const string &app, const string &stream) { deque src_list; { lock_guard lock(s_media_source_mtx); for_each_media_l(s_media_source_map, src_list, schema, vhost, app, stream); } for (auto &src : src_list) { cb(src); } } static MediaSource::Ptr find_l(const string &schema, const string &vhost_in, const string &app, const string &id, bool from_mp4) { string vhost = vhost_in; GET_CONFIG(bool, enableVhost, General::kEnableVhost); if(vhost.empty() || !enableVhost){ vhost = DEFAULT_VHOST; } if (app.empty() || id.empty()) { //如果未指定app与stream id,那么就是遍历而非查找,所以应该返回查找失败 return nullptr; } MediaSource::Ptr ret; MediaSource::for_each_media([&](const MediaSource::Ptr &src) { ret = std::move(const_cast(src)); }, schema, vhost, app, id); if(!ret && from_mp4 && schema != HLS_SCHEMA){ //未找到媒体源,则读取mp4创建一个 //播放hls不触发mp4点播(因为HLS也可以用于录像,不是纯粹的直播) ret = MediaSource::createFromMP4(schema, vhost, app, id); } return ret; } static void findAsync_l(const MediaInfo &info, const std::shared_ptr &session, bool retry, const function &cb){ auto src = find_l(info.schema, info.vhost, info.app, info.stream, true); if (src || !retry) { cb(src); return; } GET_CONFIG(int, maxWaitMS, General::kMaxStreamWaitTimeMS); void *listener_tag = session.get(); auto poller = session->getPoller(); std::shared_ptr invoked(new atomic_flag{false}); auto cb_once = [cb, invoked](const MediaSource::Ptr &src) { if (invoked->test_and_set()) { //回调已经执行过了 return; } cb(src); }; auto on_timeout = poller->doDelayTask(maxWaitMS, [cb_once, listener_tag]() { // 最多等待一定时间,如在这个时间内,流还未注册上,则返回空 NoticeCenter::Instance().delListener(listener_tag, Broadcast::kBroadcastMediaChanged); cb_once(nullptr); return 0; }); auto cancel_all = [on_timeout, listener_tag]() { //取消延时任务,防止多次回调 on_timeout->cancel(); //取消媒体注册事件监听 NoticeCenter::Instance().delListener(listener_tag, Broadcast::kBroadcastMediaChanged); }; weak_ptr weak_session = session; auto on_register = [weak_session, info, cb_once, cancel_all, poller](BroadcastMediaChangedArgs) { if (!bRegist || sender.getSchema() != info.schema || sender.getVhost() != info.vhost || sender.getApp() != info.app || sender.getId() != info.stream) { //不是自己感兴趣的事件,忽略之 return; } poller->async([weak_session, cancel_all, info, cb_once]() { cancel_all(); if (auto strong_session = weak_session.lock()) { //播发器请求的流终于注册上了,切换到自己的线程再回复 DebugL << "收到媒体注册事件,回复播放器:" << info.getUrl(); //再找一遍媒体源,一般能找到 findAsync_l(info, strong_session, false, cb_once); } }, false); }; //监听媒体注册事件 NoticeCenter::Instance().addListener(listener_tag, Broadcast::kBroadcastMediaChanged, on_register); function close_player = [cb_once, cancel_all, poller]() { poller->async([cancel_all, cb_once]() { cancel_all(); //告诉播放器,流不存在,这样会立即断开播放器 cb_once(nullptr); }); }; //广播未找到流,此时可以立即去拉流,这样还来得及 NoticeCenter::Instance().emitEvent(Broadcast::kBroadcastNotFoundStream, info, static_cast(*session), close_player); } void MediaSource::findAsync(const MediaInfo &info, const std::shared_ptr &session, const function &cb) { return findAsync_l(info, session, true, cb); } MediaSource::Ptr MediaSource::find(const string &schema, const string &vhost, const string &app, const string &id, bool from_mp4) { return find_l(schema, vhost, app, id, from_mp4); } MediaSource::Ptr MediaSource::find(const string &vhost, const string &app, const string &stream_id, bool from_mp4) { auto src = MediaSource::find(RTMP_SCHEMA, vhost, app, stream_id, from_mp4); if (src) { return src; } src = MediaSource::find(RTSP_SCHEMA, vhost, app, stream_id, from_mp4); if (src) { return src; } return MediaSource::find(HLS_SCHEMA, vhost, app, stream_id, from_mp4); } void MediaSource::emitEvent(bool regist){ auto listener = _listener.lock(); if (listener) { //触发回调 listener->onRegist(*this, regist); } //触发广播 NoticeCenter::Instance().emitEvent(Broadcast::kBroadcastMediaChanged, regist, *this); InfoL << (regist ? "媒体注册:" : "媒体注销:") << getUrl(); } void MediaSource::regist() { { //减小互斥锁临界区 lock_guard lock(s_media_source_mtx); auto &ref = s_media_source_map[_schema][_tuple.vhost][_tuple.app][_tuple.stream]; auto src = ref.lock(); if (src) { if (src.get() == this) { return; } //增加判断, 防止当前流已注册时再次注册 throw std::invalid_argument("media source already existed:" + getUrl()); } ref = shared_from_this(); } emitEvent(true); } template static bool erase_media_source(bool &hit, const MediaSource *thiz, MAP &map, const First &first, const KeyTypes &...keys) { auto it = map.find(first); if (it != map.end() && erase_media_source(hit, thiz, it->second, keys...)) { map.erase(it); } return map.empty(); } template static bool erase_media_source(bool &hit, const MediaSource *thiz, MAP &map, const First &first) { auto it = map.find(first); if (it != map.end()) { auto src = it->second.lock(); if (!src || src.get() == thiz) { //对象已经销毁或者对象就是自己,那么移除之 map.erase(it); hit = true; } } return map.empty(); } //反注册该源 bool MediaSource::unregist() { bool ret = false; { //减小互斥锁临界区 lock_guard lock(s_media_source_mtx); erase_media_source(ret, this, s_media_source_map, _schema, _tuple.vhost, _tuple.app, _tuple.stream); } if (ret) { emitEvent(false); } return ret; } /////////////////////////////////////MediaInfo////////////////////////////////////// void MediaInfo::parse(const std::string &url_in){ full_url = url_in; auto url = url_in; auto pos = url.find("?"); if (pos != string::npos) { param_strs = url.substr(pos + 1); url.erase(pos); } auto schema_pos = url.find("://"); if (schema_pos != string::npos) { schema = url.substr(0, schema_pos); } else { schema_pos = -3; } auto split_vec = split(url.substr(schema_pos + 3), "/"); if (split_vec.size() > 0) { splitUrl(split_vec[0], host, port); vhost = host; if (vhost == "localhost" || isIP(vhost.data())) { //如果访问的是localhost或ip,那么则为默认虚拟主机 vhost = DEFAULT_VHOST; } } if (split_vec.size() > 1) { app = split_vec[1]; } if (split_vec.size() > 2) { string stream_id; for (size_t i = 2; i < split_vec.size(); ++i) { stream_id.append(split_vec[i] + "/"); } if (stream_id.back() == '/') { stream_id.pop_back(); } stream = stream_id; } auto params = Parser::parseArgs(param_strs); if (params.find(VHOST_KEY) != params.end()) { vhost = params[VHOST_KEY]; } GET_CONFIG(bool, enableVhost, General::kEnableVhost); if (!enableVhost || vhost.empty()) { //如果关闭虚拟主机或者虚拟主机为空,则设置虚拟主机为默认 vhost = DEFAULT_VHOST; } } MediaSource::Ptr MediaSource::createFromMP4(const string &schema, const string &vhost, const string &app, const string &stream, const string &file_path , bool check_app){ GET_CONFIG(string, appName, Record::kAppName); if (check_app && app != appName) { return nullptr; } #ifdef ENABLE_MP4 try { auto reader = std::make_shared(vhost, app, stream, file_path); reader->startReadMP4(); return MediaSource::find(schema, vhost, app, stream); } catch (std::exception &ex) { WarnL << ex.what(); return nullptr; } #else WarnL << "创建MP4点播失败,请编译时打开\"ENABLE_MP4\"选项"; return nullptr; #endif //ENABLE_MP4 } /////////////////////////////////////MediaSourceEvent////////////////////////////////////// void MediaSourceEvent::onReaderChanged(MediaSource &sender, int size){ if (size || sender.totalReaderCount()) { //还有人观看该视频,不触发关闭事件 _async_close_timer = nullptr; return; } //没有任何人观看该视频源,表明该源可以关闭了 GET_CONFIG(string, record_app, Record::kAppName); GET_CONFIG(int, stream_none_reader_delay, General::kStreamNoneReaderDelayMS); //如果mp4点播, 无人观看时我们强制关闭点播 bool is_mp4_vod = sender.getApp() == record_app; weak_ptr weak_sender = sender.shared_from_this(); _async_close_timer = std::make_shared(stream_none_reader_delay / 1000.0f, [weak_sender, is_mp4_vod]() { auto strong_sender = weak_sender.lock(); if (!strong_sender) { //对象已经销毁 return false; } if (strong_sender->totalReaderCount()) { //还有人观看该视频,不触发关闭事件 return false; } if (!is_mp4_vod) { //直播时触发无人观看事件,让开发者自行选择是否关闭 NoticeCenter::Instance().emitEvent(Broadcast::kBroadcastStreamNoneReader, *strong_sender); } else { //这个是mp4点播,我们自动关闭 WarnL << "MP4点播无人观看,自动关闭:" << strong_sender->getUrl(); strong_sender->close(false); } return false; }, nullptr); } string MediaSourceEvent::getOriginUrl(MediaSource &sender) const { return sender.getUrl(); } MediaOriginType MediaSourceEventInterceptor::getOriginType(MediaSource &sender) const { auto listener = _listener.lock(); if (!listener) { return MediaOriginType::unknown; } return listener->getOriginType(sender); } string MediaSourceEventInterceptor::getOriginUrl(MediaSource &sender) const { auto listener = _listener.lock(); if (!listener) { return MediaSourceEvent::getOriginUrl(sender); } auto ret = listener->getOriginUrl(sender); if (!ret.empty()) { return ret; } return MediaSourceEvent::getOriginUrl(sender); } std::shared_ptr MediaSourceEventInterceptor::getOriginSock(MediaSource &sender) const { auto listener = _listener.lock(); if (!listener) { return nullptr; } return listener->getOriginSock(sender); } bool MediaSourceEventInterceptor::seekTo(MediaSource &sender, uint32_t stamp) { auto listener = _listener.lock(); if (!listener) { return false; } return listener->seekTo(sender, stamp); } bool MediaSourceEventInterceptor::pause(MediaSource &sender, bool pause) { auto listener = _listener.lock(); if (!listener) { return false; } return listener->pause(sender, pause); } bool MediaSourceEventInterceptor::speed(MediaSource &sender, float speed) { auto listener = _listener.lock(); if (!listener) { return false; } return listener->speed(sender, speed); } bool MediaSourceEventInterceptor::close(MediaSource &sender) { auto listener = _listener.lock(); if (!listener) { return false; } return listener->close(sender); } int MediaSourceEventInterceptor::totalReaderCount(MediaSource &sender) { auto listener = _listener.lock(); if (!listener) { return sender.readerCount(); } return listener->totalReaderCount(sender); } void MediaSourceEventInterceptor::onReaderChanged(MediaSource &sender, int size) { auto listener = _listener.lock(); if (!listener) { MediaSourceEvent::onReaderChanged(sender, size); } else { listener->onReaderChanged(sender, size); } } void MediaSourceEventInterceptor::onRegist(MediaSource &sender, bool regist) { auto listener = _listener.lock(); if (listener) { listener->onRegist(sender, regist); } } float MediaSourceEventInterceptor::getLossRate(MediaSource &sender, TrackType type){ auto listener = _listener.lock(); if (listener) { return listener->getLossRate(sender, type); } return -1; //异常返回-1 } toolkit::EventPoller::Ptr MediaSourceEventInterceptor::getOwnerPoller(MediaSource &sender) { auto listener = _listener.lock(); if (listener) { return listener->getOwnerPoller(sender); } throw std::runtime_error(toolkit::demangle(typeid(*this).name()) + "::getOwnerPoller failed"); } bool MediaSourceEventInterceptor::setupRecord(MediaSource &sender, Recorder::type type, bool start, const string &custom_path, size_t max_second) { auto listener = _listener.lock(); if (!listener) { return false; } return listener->setupRecord(sender, type, start, custom_path, max_second); } bool MediaSourceEventInterceptor::isRecording(MediaSource &sender, Recorder::type type) { auto listener = _listener.lock(); if (!listener) { return false; } return listener->isRecording(sender, type); } vector MediaSourceEventInterceptor::getMediaTracks(MediaSource &sender, bool trackReady) const { auto listener = _listener.lock(); if (!listener) { return vector(); } return listener->getMediaTracks(sender, trackReady); } void MediaSourceEventInterceptor::startSendRtp(MediaSource &sender, const MediaSourceEvent::SendRtpArgs &args, const std::function cb) { auto listener = _listener.lock(); if (listener) { listener->startSendRtp(sender, args, cb); } else { MediaSourceEvent::startSendRtp(sender, args, cb); } } bool MediaSourceEventInterceptor::stopSendRtp(MediaSource &sender, const string &ssrc){ auto listener = _listener.lock(); if (listener) { return listener->stopSendRtp(sender, ssrc); } return false; } void MediaSourceEventInterceptor::setDelegate(const std::weak_ptr &listener) { if (listener.lock().get() == this) { throw std::invalid_argument("can not set self as a delegate"); } _listener = listener; } std::shared_ptr MediaSourceEventInterceptor::getDelegate() const{ return _listener.lock(); } /////////////////////////////////////FlushPolicy////////////////////////////////////// static bool isFlushAble_default(bool is_video, uint64_t last_stamp, uint64_t new_stamp, size_t cache_size) { if (new_stamp + 500 < last_stamp) { //时间戳回退比较大(可能seek中),由于rtp中时间戳是pts,是可能存在一定程度的回退的 return true; } //时间戳发送变化或者缓存超过1024个,sendmsg接口一般最多只能发送1024个数据包 return last_stamp != new_stamp || cache_size >= 1024; } static bool isFlushAble_merge(bool is_video, uint64_t last_stamp, uint64_t new_stamp, size_t cache_size, int merge_ms) { if (new_stamp + 500 < last_stamp) { //时间戳回退比较大(可能seek中),由于rtp中时间戳是pts,是可能存在一定程度的回退的 return true; } if (new_stamp > last_stamp + merge_ms) { //时间戳增量超过合并写阈值 return true; } //缓存数超过1024个,这个逻辑用于避免时间戳异常的流导致的内存暴增问题 //而且sendmsg接口一般最多只能发送1024个数据包 return cache_size >= 1024; } bool FlushPolicy::isFlushAble(bool is_video, bool is_key, uint64_t new_stamp, size_t cache_size) { bool flush_flag = false; if (is_key && is_video) { //遇到关键帧flush掉前面的数据,确保关键帧为该组数据的第一帧,确保GOP缓存有效 flush_flag = true; } else { GET_CONFIG(int, mergeWriteMS, General::kMergeWriteMS); if (mergeWriteMS <= 0) { //关闭了合并写或者合并写阈值小于等于0 flush_flag = isFlushAble_default(is_video, _last_stamp[is_video], new_stamp, cache_size); } else { flush_flag = isFlushAble_merge(is_video, _last_stamp[is_video], new_stamp, cache_size, mergeWriteMS); } } if (flush_flag) { _last_stamp[is_video] = new_stamp; } return flush_flag; } } /* namespace mediakit */