extern "C" {
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
-#include <libavformat/avio.h>
}
+#include <sys/types.h>
+#include <atomic>
+#include <condition_variable>
+#include <functional>
#include <mutex>
-#include <queue>
+#include <string>
+#include <utility>
+#include <thread>
#include <vector>
-class KeyFrameSignalReceiver {
-public:
- // Needs to automatically turn the flag off again after actually receiving data.
- virtual void signal_keyframe() = 0;
+#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 {
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. <keyframe_signal_receiver> can be nullptr.
- Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, const std::string &video_extradata, const AVCodecContext *audio_ctx, int time_base, KeyFrameSignalReceiver *keyframe_signal_receiver);
+ // 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);
+ 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
void unplug();
private:
- void add_interleaved_packet(const AVPacket &pkt); // Must be called with <mu> held.
- void write_packet_with_signal(const AVPacket &pkt); // Must be called with <mu> held.
+ // 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;
- AVFormatContext *avctx; // Protected by <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>.
- std::vector<AVPacket *> plugged_packets; // Protected by <mu>.
-
- // We need to do our own interleaving since we do explicit flushes
- // before each keyframe. This queue contains every packet that we
- // couldn't send yet, in add order. Essentially, we can't send a packet
- // before we know we cannot receive an earlier (dts-wise) packet
- // from another stream. This means that this queue will either contain
- // video packets only or audio packets only, and as soon as a packet
- // of the other type comes in, we can empty the flush the queue up
- // to that point.
- // Protected by <mu>.
- std::queue<AVPacket *> waiting_packets;
+
+ // 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;
- KeyFrameSignalReceiver *keyframe_signal_receiver;
+
+ std::function<void(int64_t)> write_callback;
+ std::vector<MuxMetrics *> metrics;
+
+ friend struct PacketBefore;
};
#endif // !defined(_MUX_H)