Drop buffered SRT data if the connection is down for too long.

[nageru] / shared / mux.cpp

diff --git a/shared/mux.cpp b/shared/mux.cpp
index 819638c480c04f22a98a6364ecf1b1cb59ef569c..a52f21fbdab35b18bae0161cab70b9bd5d6013dd 100644 (file)
--- a/shared/mux.cpp
+++ b/shared/mux.cpp
@@ -124,27 +124,10 @@ Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, const
                subtitle_stream_idx = streams.size() - 1;
        }
 
-       AVDictionary *options = NULL;
-       vector<pair<string, string>> opts = MUX_OPTS;
-       for (pair<string, string> opt : opts) {
-               av_dict_set(&options, opt.first.c_str(), opt.second.c_str(), 0);
-       }
-       int err = avformat_write_header(avctx, &options);
-       if (err < 0) {
-               char errbuf[AV_ERROR_MAX_STRING_SIZE];
-               av_strerror(err, errbuf, sizeof(errbuf));
-               fprintf(stderr, "avformat_write_header() failed: %s\n", errbuf);
-               exit(EXIT_FAILURE);
-       }
-       for (MuxMetrics *metric : metrics) {
-               metric->metric_written_bytes += avctx->pb->pos;
-       }
-
-       // Make sure the header is written before the constructor exits.
-       avio_flush(avctx->pb);
-
        if (write_strategy == WRITE_BACKGROUND) {
                writer_thread = thread(&Mux::thread_func, this);
+       } else {
+               write_header();
        }
 }
 
@@ -174,7 +157,6 @@ void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational t
        assert(pts >= dts);
 
        AVPacket pkt_copy;
-       av_init_packet(&pkt_copy);
        if (av_packet_ref(&pkt_copy, &pkt) < 0) {
                fprintf(stderr, "av_copy_packet() failed\n");
                abort();
@@ -190,7 +172,9 @@ void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational t
 
        {
                lock_guard<mutex> lock(mu);
-               if (write_strategy == WriteStrategy::WRITE_BACKGROUND) {
+               if (drained) {
+                       // Just drop the packet on the floor.
+               } else if (write_strategy == WriteStrategy::WRITE_BACKGROUND) {
                        packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
                        if (plug_count == 0)
                                packet_queue_ready.notify_all();
@@ -236,6 +220,7 @@ void Mux::write_packet_or_die(const AVPacket &pkt, int64_t unscaled_pts)
 void Mux::plug()
 {
        lock_guard<mutex> lock(mu);
+       assert(!drained);
        ++plug_count;
 }
 
@@ -260,10 +245,31 @@ void Mux::unplug()
        }
 }
 
+void Mux::drain()
+{
+       lock_guard<mutex> lock(mu);
+       assert(!drained);
+       assert(plug_count == 0);
+       for (QueuedPacket &qp : packet_queue) {
+               av_packet_free(&qp.pkt);
+       }
+       packet_queue.clear();
+       drained = true;
+}
+
+void Mux::undrain()
+{
+       lock_guard<mutex> lock(mu);
+       assert(drained);
+       drained = false;
+}
+
 void Mux::thread_func()
 {
        pthread_setname_np(pthread_self(), "Mux");
 
+       write_header();
+
        unique_lock<mutex> lock(mu);
        for ( ;; ) {
                packet_queue_ready.wait(lock, [this]() {
@@ -287,6 +293,31 @@ void Mux::thread_func()
        }
 }
 
+void Mux::write_header()
+{
+       AVDictionary *options = NULL;
+       vector<pair<string, string>> opts = MUX_OPTS;
+       for (pair<string, string> opt : opts) {
+               av_dict_set(&options, opt.first.c_str(), opt.second.c_str(), 0);
+       }
+
+       int err = avformat_write_header(avctx, &options);
+       if (err < 0) {
+               char errbuf[AV_ERROR_MAX_STRING_SIZE];
+               av_strerror(err, errbuf, sizeof(errbuf));
+               fprintf(stderr, "avformat_write_header() failed: %s\n", errbuf);
+               exit(EXIT_FAILURE);
+       }
+       for (MuxMetrics *metric : metrics) {
+               metric->metric_written_bytes += avctx->pb->pos;
+       }
+
+       // Make sure the header is written before the constructor exits
+       // (assuming we are in WRITE_FOREGROUND mode).
+       avio_flush(avctx->pb);
+
+}
+
 void MuxMetrics::init(const vector<pair<string, string>> &labels)
 {
        vector<pair<string, string>> labels_video = labels;