X-Git-Url: https://git.sesse.net/?p=nageru;a=blobdiff_plain;f=mux.h;h=e6193e0a36c92ec0258f3680df597a37f15ce26f;hp=47ff775d8cdf2d0faa2148ae1b55100d2bbcd8b1;hb=refs%2Fheads%2Fcef;hpb=acc9fe1e6be3e7b1c95f44e45728ec3beae576b0

diff --git a/mux.h b/mux.h
index 47ff775..e6193e0 100644
--- a/mux.h
+++ b/mux.h
@@ -6,31 +6,106 @@
 extern "C" {
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
-#include <libavformat/avio.h>
 }
 
-class PacketDestination {
-public:
-	virtual ~PacketDestination() {}
-	virtual void add_packet(const AVPacket &pkt, int64_t pts, int64_t dts) = 0;
+#include <sys/types.h>
+#include <atomic>
+#include <condition_variable>
+#include <functional>
+#include <mutex>
+#include <string>
+#include <utility>
+#include <thread>
+#include <vector>
+
+#include "timebase.h"
+
+struct MuxMetrics {
+	// “written” will usually be equal video + audio + mux overhead,
+	// except that there could be buffered packets that count in audio or video
+	// but not yet in written.
+	std::atomic<int64_t> metric_video_bytes{0}, metric_audio_bytes{0}, metric_written_bytes{0};
+
+	// Registers in global_metrics.
+	void init(const std::vector<std::pair<std::string, std::string>> &labels);
+
+	void reset()
+	{
+		metric_video_bytes = 0;
+		metric_audio_bytes = 0;
+		metric_written_bytes = 0;
+	}
 };
 
-class Mux : public PacketDestination {
+class Mux {
 public:
 	enum Codec {
 		CODEC_H264,
 		CODEC_NV12,  // Uncompressed 4:2:0.
 	};
+	enum WriteStrategy {
+		// add_packet() will write the packet immediately, unless plugged.
+		WRITE_FOREGROUND,
 
-	// Takes ownership of avctx.
-	Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, const AVCodec *codec_audio, int time_base, int bit_rate);
+		// All writes will happen on a separate thread, so add_packet()
+		// won't block. Use this if writing to a file and you might be
+		// holding a mutex (because blocking I/O with a mutex held is
+		// not good). Note that this will clone every packet, so it has
+		// higher overhead.
+		WRITE_BACKGROUND,
+	};
+
+	// Takes ownership of avctx. <write_callback> will be called every time
+	// a write has been made to the video stream (id 0), with the pts of
+	// the just-written frame. (write_callback can be nullptr.)
+	// Does not take ownership of <metrics>; elements in there, if any,
+	// will be added to.
+	Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, const std::string &video_extradata, const AVCodecParameters *audio_codecpar, int time_base, std::function<void(int64_t)> write_callback, WriteStrategy write_strategy, const std::vector<MuxMetrics *> &metrics);
 	~Mux();
-	void add_packet(const AVPacket &pkt, int64_t pts, int64_t dts) override;
+	void add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational timebase = { 1, TIMEBASE });
+
+	// As long as the mux is plugged, it will not actually write anything to disk,
+	// just queue the packets. Once it is unplugged, the packets are reordered by pts
+	// and written. This is primarily useful if you might have two different encoders
+	// writing to the mux at the same time (because one is shutting down), so that
+	// pts might otherwise come out-of-order.
+	//
+	// You can plug and unplug multiple times; only when the plug count reaches zero,
+	// something will actually happen.
+	void plug();
+	void unplug();
 
 private:
-	bool seen_keyframe = false;
-	AVFormatContext *avctx;
+	// If write_strategy == WRITE_FOREGORUND, Must be called with <mu> held.
+	void write_packet_or_die(const AVPacket &pkt, int64_t unscaled_pts);
+	void thread_func();
+
+	WriteStrategy write_strategy;
+
+	std::mutex mu;
+
+	// These are only in use if write_strategy == WRITE_BACKGROUND.
+	std::atomic<bool> writer_thread_should_quit{false};
+	std::thread writer_thread;
+
+	AVFormatContext *avctx;  // Protected by <mu>, iff write_strategy == WRITE_BACKGROUND.
+	int plug_count = 0;  // Protected by <mu>.
+
+	// Protected by <mu>. If write_strategy == WRITE_FOREGROUND,
+	// this is only in use when plugging.
+	struct QueuedPacket {
+		AVPacket *pkt;
+		int64_t unscaled_pts;
+	};
+	std::vector<QueuedPacket> packet_queue;
+	std::condition_variable packet_queue_ready;
+
 	AVStream *avstream_video, *avstream_audio;
+
+	std::function<void(int64_t)> write_callback;
+	std::vector<MuxMetrics *> metrics;
+
+	friend struct PacketBefore;
 };
 
 #endif  // !defined(_MUX_H)