Add hls_delay feature (#3158)

conf/config.ini

@@ -135,6 +135,8 @@ segDur=2
 #m3u8索引中,hls保留切片个数(实际保留切片个数大2~3个)
 #如果设置为0，则不删除切片，而是保存为点播
 segNum=3
+#HLS切片延迟个数，大于0将生成hls_delay.m3u8文件，0则不生成
+segDelay=0
 #HLS切片从m3u8文件中移除后，继续保留在磁盘上的个数
 segRetain=5
 #是否广播 hls切片(ts/fmp4)完成通知(on_record_ts)

src/Common/config.cpp

@@ -307,6 +307,7 @@ namespace Hls {
 const string kSegmentDuration = HLS_FIELD "segDur";
 const string kSegmentNum = HLS_FIELD "segNum";
 const string kSegmentKeep = HLS_FIELD "segKeep";
+const string kSegmentDelay = HLS_FIELD "segDelay";
 const string kSegmentRetain = HLS_FIELD "segRetain";
 const string kFileBufSize = HLS_FIELD "fileBufSize";
 const string kBroadcastRecordTs = HLS_FIELD "broadcastRecordTs";
@@ -317,6 +318,7 @@ static onceToken token([]() {
     mINI::Instance()[kSegmentDuration] = 2;
     mINI::Instance()[kSegmentNum] = 3;
     mINI::Instance()[kSegmentKeep] = false;
+    mINI::Instance()[kSegmentDelay] = 0;
     mINI::Instance()[kSegmentRetain] = 5;
     mINI::Instance()[kFileBufSize] = 64 * 1024;
     mINI::Instance()[kBroadcastRecordTs] = false;

src/Common/config.h

@@ -349,6 +349,8 @@ extern const std::string kSegmentDuration;
 extern const std::string kSegmentNum;
 // 如果设置为0，则不保留切片，设置为1则一直保留切片
 extern const std::string kSegmentKeep;
+// HLS切片延迟个数，大于0将生成hls_delay.m3u8文件，0则不生成
+extern const std::string kSegmentDelay;
 // HLS切片从m3u8文件中移除后，继续保留在磁盘上的个数
 extern const std::string kSegmentRetain;
 // HLS文件写缓存大小

src/Record/HlsMaker.cpp

@@ -24,15 +24,40 @@ HlsMaker::HlsMaker(bool is_fmp4, float seg_duration, uint32_t seg_number, bool s
     _seg_keep = seg_keep;
 }
 
-void HlsMaker::makeIndexFile(bool eof) {
+void HlsMaker::makeIndexFile(bool include_delay, bool eof) {
+    GET_CONFIG(uint32_t, segDelay, Hls::kSegmentDelay);
+    GET_CONFIG(uint32_t, segRetain, Hls::kSegmentRetain);
+    std::deque<std::tuple<int, std::string>> temp(_seg_dur_list);
+    if (!include_delay) {
+        while (temp.size() > _seg_number) {
+            temp.pop_front();
+        }
+    }
     int maxSegmentDuration = 0;
-    for (auto &tp : _seg_dur_list) {
+    for (auto &tp : temp) {
         int dur = std::get<0>(tp);
         if (dur > maxSegmentDuration) {
             maxSegmentDuration = dur;
         }
     }
-    auto index_seq = _seg_number ? (_file_index > _seg_number ? _file_index - _seg_number : 0LL) : 0LL;
+    uint64_t index_seq;
+    if (_seg_number) {
+        if (include_delay) {
+            if (_file_index > _seg_number + segDelay) {
+                index_seq = _file_index - _seg_number - segDelay;
+            } else {
+                index_seq = 0LL;
+            }
+        } else {
+            if (_file_index > _seg_number) {
+                index_seq = _file_index - _seg_number;
+            } else {
+                index_seq = 0LL;
+            }
+        }
+    } else {
+        index_seq = 0LL;
+    }
 
     string index_str;
     index_str.reserve(2048);
@@ -50,7 +75,7 @@ void HlsMaker::makeIndexFile(bool eof) {
     }
 
     stringstream ss;
-    for (auto &tp : _seg_dur_list) {
+    for (auto &tp : temp) {
         ss << "#EXTINF:" << std::setprecision(3) << std::get<0>(tp) / 1000.0 << ",\n" << std::get<1>(tp) << "\n";
     }
     index_str += ss.str();
@@ -58,7 +83,7 @@ void HlsMaker::makeIndexFile(bool eof) {
     if (eof) {
         index_str += "#EXT-X-ENDLIST\n";
     }
-    onWriteHls(index_str);
+    onWriteHls(index_str, include_delay);
 }
 
 void HlsMaker::inputInitSegment(const char *data, size_t len) {
@@ -91,12 +116,13 @@ void HlsMaker::inputData(const char *data, size_t len, uint64_t timestamp, bool
 }
 
 void HlsMaker::delOldSegment() {
+    GET_CONFIG(uint32_t, segDelay, Hls::kSegmentDelay);
     if (_seg_number == 0) {
         //如果设置为保留0个切片，则认为是保存为点播
         return;
     }
     //在hls m3u8索引文件中,我们保存的切片个数跟_seg_number相关设置一致
-    if (_file_index > _seg_number) {
+    if (_file_index > _seg_number + segDelay) {
         _seg_dur_list.pop_front();
     }
     //如果设置为一直保存，就不删除
@@ -105,8 +131,8 @@ void HlsMaker::delOldSegment() {
     }
     GET_CONFIG(uint32_t, segRetain, Hls::kSegmentRetain);
     //但是实际保存的切片个数比m3u8所述多若干个,这样做的目的是防止播放器在切片删除前能下载完毕
-    if (_file_index > _seg_number + segRetain) {
-        onDelSegment(_file_index - _seg_number - segRetain - 1);
+    if (_file_index > _seg_number + segDelay + segRetain) {
+        onDelSegment(_file_index - _seg_number - segDelay - segRetain - 1);
     }
 }
 
@@ -125,6 +151,7 @@ void HlsMaker::addNewSegment(uint64_t stamp) {
 }
 
 void HlsMaker::flushLastSegment(bool eof){
+    GET_CONFIG(uint32_t, segDelay, Hls::kSegmentDelay);
     if (_last_file_name.empty()) {
         //不存在上个切片
         return;
@@ -139,7 +166,11 @@ void HlsMaker::flushLastSegment(bool eof){
     //先flush ts切片，否则可能存在ts文件未写入完毕就被访问的情况
     onFlushLastSegment(seg_dur);
     //然后写m3u8文件
-    makeIndexFile(eof);
+    makeIndexFile(false, eof);
+    //写入切片延迟的m3u8文件
+    if (segDelay) {
+        makeIndexFile(true, eof);
+    }
 }
 
 bool HlsMaker::isLive() const {

src/Record/HlsMaker.h

@@ -96,7 +96,7 @@ protected:
     /**
      * 写m3u8文件回调
      */
-    virtual void onWriteHls(const std::string &data) = 0;
+    virtual void onWriteHls(const std::string &data, bool include_delay) = 0;
 
     /**
      * 上一个 ts 切片写入完成, 可在这里进行通知处理
@@ -115,7 +115,7 @@ private:
      * 生成m3u8文件
      * @param eof true代表点播
      */
-    void makeIndexFile(bool eof = false);
+    void makeIndexFile(bool include_delay, bool eof = false);
 
     /**
      * 删除旧的ts切片

src/Record/HlsMakerImp.cpp

@@ -21,11 +21,20 @@ using namespace toolkit;
 
 namespace mediakit {
 
+std::string getDelayPath(const std::string& originalPath) {
+    std::size_t pos = originalPath.find(".m3u8");
+    if (pos != std::string::npos) {
+        return originalPath.substr(0, pos) + "_delay.m3u8";
+    }
+    return originalPath;
+}
+
 HlsMakerImp::HlsMakerImp(bool is_fmp4, const string &m3u8_file, const string &params, uint32_t bufSize, float seg_duration,
                          uint32_t seg_number, bool seg_keep) : HlsMaker(is_fmp4, seg_duration, seg_number, seg_keep) {
     _poller = EventPollerPool::Instance().getPoller();
     _path_prefix = m3u8_file.substr(0, m3u8_file.rfind('/'));
     _path_hls = m3u8_file;
+    _path_hls_delay = getDelayPath(m3u8_file);
     _params = params;
     _buf_size = bufSize;
     _file_buf.reset(new char[bufSize], [](char *ptr) { delete[] ptr; });
@@ -62,6 +71,7 @@ void HlsMakerImp::clearCache(bool immediately, bool eof) {
     {
         std::list<std::string> lst;
         lst.emplace_back(_path_hls);
+        lst.emplace_back(_path_hls_delay);
         if (!_path_init.empty()) {
             lst.emplace_back(_path_init);
         }
@@ -146,8 +156,9 @@ void HlsMakerImp::onWriteSegment(const char *data, size_t len) {
     }
 }
 
-void HlsMakerImp::onWriteHls(const std::string &data) {
-    auto hls = makeFile(_path_hls);
+void HlsMakerImp::onWriteHls(const std::string &data, bool include_delay) {
+    auto path = include_delay ? _path_hls_delay : _path_hls;
+    auto hls = makeFile(path);
     if (hls) {
         fwrite(data.data(), data.size(), 1, hls.get());
         hls.reset();
@@ -155,7 +166,7 @@ void HlsMakerImp::onWriteHls(const std::string &data) {
             _media_src->setIndexFile(data);
         }
     } else {
-        WarnL << "Create hls file failed," << _path_hls << " " << get_uv_errmsg();
+        WarnL << "Create hls file failed," << path << " " << get_uv_errmsg();
     }
 }
 

src/Record/HlsMakerImp.h

@@ -49,7 +49,7 @@ protected:
     void onDelSegment(uint64_t index) override;
     void onWriteInitSegment(const char *data, size_t len) override;
     void onWriteSegment(const char *data, size_t len) override;
-    void onWriteHls(const std::string &data) override;
+    void onWriteHls(const std::string &data, bool include_delay) override;
     void onFlushLastSegment(uint64_t duration_ms) override;
 
 private:
@@ -60,6 +60,7 @@ private:
     int _buf_size;
     std::string _params;
     std::string _path_hls;
+    std::string _path_hls_delay;
     std::string _path_init;
     std::string _path_prefix;
     RecordInfo _info;