X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=shared%2Fmux.cpp;h=adec53de7923171842d90822a7ec8600b9e78fd0;hb=HEAD;hp=0a2eaef6a8310f53b5f7ea0d9a175ea1eb226570;hpb=ee6ece72bc12e5527e114e0e1973f0c0b2dc2138;p=nageru

diff --git a/shared/mux.cpp b/shared/mux.cpp
index 0a2eaef..a52f21f 100644
--- a/shared/mux.cpp
+++ b/shared/mux.cpp
@@ -50,6 +50,13 @@ struct PacketBefore {
 Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, const string &video_extradata, const AVCodecParameters *audio_codecpar, AVColorSpace color_space, int time_base, function<void(int64_t)> write_callback, WriteStrategy write_strategy, const vector<MuxMetrics *> &metrics, WithSubtitles with_subtitles)
 	: write_strategy(write_strategy), avctx(avctx), write_callback(write_callback), metrics(metrics)
 {
+	// MPEG-TS ostensibly needs some conversions (e.g. for differing start codes),
+	// so let FFmpeg insert them as needed in case we are muxing to that.
+	// Curiously enough, things actually seem to go quite fine without
+	// (and it also seems FFmpeg's MPEG-TS muxer automatically does stuff like
+	// repeat PPS/SPS before keyframes for us), but it can't hurt.
+	avctx->flags |= AVFMT_FLAG_AUTO_BSF;
+
 	AVStream *avstream_video = avformat_new_stream(avctx, nullptr);
 	if (avstream_video == nullptr) {
 		fprintf(stderr, "avformat_new_stream() failed\n");
@@ -61,9 +68,6 @@ Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, const
 		avstream_video->codecpar->codec_id = AV_CODEC_ID_H264;
 	} else if (video_codec == CODEC_AV1) {
 		avstream_video->codecpar->codec_id = AV_CODEC_ID_AV1;
-	} else if (video_codec == CODEC_NV12) {
-		avstream_video->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
-		avstream_video->codecpar->codec_tag = avcodec_pix_fmt_to_codec_tag(AV_PIX_FMT_NV12);
 	} else {
 		assert(video_codec == CODEC_MJPEG);
 		avstream_video->codecpar->codec_id = AV_CODEC_ID_MJPEG;
@@ -120,27 +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();
 	}
 }
 
@@ -167,8 +154,9 @@ Mux::~Mux()
 
 void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational timebase, int stream_index_override)
 {
+	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();
@@ -184,7 +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();
@@ -230,6 +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;
 }
 
@@ -254,10 +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]() {
@@ -281,6 +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;