Mark a TODO.

[nageru] / futatabi / player.h

#ifndef _PLAYER_H
#define _PLAYER_H 1

#include "clip_list.h"
#include "frame_on_disk.h"
#include "queue_spot_holder.h"

extern "C" {
#include <libavformat/avformat.h>
#include <libavformat/avio.h>
}

#include <condition_variable>
#include <functional>
#include <mutex>
#include <thread>

class JPEGFrameView;
class VideoStream;
class QSurface;
class QSurfaceFormat;

class Player : public QueueInterface {
public:
        enum StreamOutput {
                NO_STREAM_OUTPUT,
                HTTPD_STREAM_OUTPUT,  // Output to global_httpd.
                FILE_STREAM_OUTPUT    // Output to file_avctx.
        };
        Player(JPEGFrameView *destination, StreamOutput stream_output, AVFormatContext *file_avctx = nullptr);
        ~Player();

        void play(const Clip &clip)
        {
                play({ ClipWithID{ clip, 0 } });
        }
        void play(const std::vector<ClipWithID> &clips);
        void override_angle(unsigned stream_idx);  // Assumes one-clip playlist only.

        // Replace the part of the playlist that we haven't started playing yet
        // (ie., from the point immediately after the last current playing clip
        // and to the end) with the given one.
        //
        // E.g., if we have the playlist A, B, C, D, E, F, we're currently in a fade
        // from B to C and run splice_play() with the list G, C, H, I, the resulting
        // list will be A, B, C, H, I. (If the new list doesn't contain B nor C,
        // there will be some heuristics.) Note that we always compare on ID only;
        // changes will be ignored for the purposes of setting the split point,
        // although the newly-spliced entries will of course get the new in/out points
        // etc., which is the main reason for going through this exercise in the first
        // place.
        //
        // If nothing is playing, the call will be ignored.
        void splice_play(const std::vector<ClipWithID> &clips);

        // Set the status string that will be used for the video stream's status subtitles
        // whenever we are not playing anything.
        void set_pause_status(const std::string &status)
        {
                std::lock_guard<std::mutex> lock(queue_state_mu);
                pause_status = status;
        }

        void skip_to_next()
        {
                should_skip_to_next = true;
        }

        void set_master_speed(float speed)
        {
                change_master_speed = speed;
        }

        // Not thread-safe to set concurrently with playing.
        // Will be called back from the player thread.
        using done_callback_func = std::function<void()>;
        void set_done_callback(done_callback_func cb) { done_callback = cb; }

        // Not thread-safe to set concurrently with playing.
        // Will be called back from the player thread.
        // The keys in the given map are row members in the vector given to play().
        using progress_callback_func = std::function<void(const std::map<uint64_t, double> &progress, double time_remaining)>;
        void set_progress_callback(progress_callback_func cb) { progress_callback = cb; }

        // QueueInterface.
        void take_queue_spot() override;
        void release_queue_spot() override;

private:
        void thread_func(AVFormatContext *file_avctx);
        void play_playlist_once();
        void display_single_frame(int primary_stream_idx, const FrameOnDisk &primary_frame, int secondary_stream_idx, const FrameOnDisk &secondary_frame, double fade_alpha, std::chrono::steady_clock::time_point frame_start, bool snapped, const std::string &subtitle);
        void open_output_stream();
        static int write_packet2_thunk(void *opaque, uint8_t *buf, int buf_size, AVIODataMarkerType type, int64_t time);
        int write_packet2(uint8_t *buf, int buf_size, AVIODataMarkerType type, int64_t time);

        // Find the frame immediately before and after this point.
        // Returns false if pts is after the last frame.
        bool find_surrounding_frames(int64_t pts, int stream_idx, FrameOnDisk *frame_lower, FrameOnDisk *frame_upper);

        std::thread player_thread;
        std::atomic<bool> should_quit{ false };
        std::atomic<bool> should_skip_to_next{ false };
        std::atomic<float> change_master_speed{ 0.0f / 0.0f };

        JPEGFrameView *destination;
        done_callback_func done_callback;
        progress_callback_func progress_callback;

        std::mutex queue_state_mu;
        std::condition_variable new_clip_changed;
        std::vector<ClipWithID> queued_clip_list;  // Under queue_state_mu.
        bool new_clip_ready = false;  // Under queue_state_mu.
        bool playing = false;  // Under queue_state_mu.
        int override_stream_idx = -1;  // Under queue_state_mu.
        int64_t last_pts_played = -1;  // Under queue_state_mu. Used by previews only.

        bool splice_ready = false;  // Under queue_state_mu.
        std::vector<ClipWithID> to_splice_clip_list;  // Under queue_state_mu.
        std::string pause_status = "paused";  // Under queue_state_mu.

        std::unique_ptr<VideoStream> video_stream;  // Can be nullptr.

        std::atomic<int64_t> metric_dropped_interpolated_frame{ 0 };
        std::atomic<int64_t> metric_dropped_unconditional_frame{ 0 };
        std::atomic<int64_t> metric_faded_frame{ 0 };
        std::atomic<int64_t> metric_faded_snapped_frame{ 0 };
        std::atomic<int64_t> metric_original_frame{ 0 };
        std::atomic<int64_t> metric_original_snapped_frame{ 0 };
        std::atomic<int64_t> metric_refresh_frame{ 0 };
        std::atomic<int64_t> metric_interpolated_frame{ 0 };
        std::atomic<int64_t> metric_interpolated_faded_frame{ 0 };

        // under queue_state_mu. Part of this instead of VideoStream so that we own
        // its lock and can sleep on it.
        size_t num_queued_frames = 0;
        static constexpr size_t max_queued_frames = 10;

        // State private to the player thread.
        int64_t pts = 0;
        const StreamOutput stream_output;
};

double compute_time_left(const std::vector<ClipWithID> &clips, size_t currently_playing_idx, double progress_currently_playing);

static inline double compute_total_time(const std::vector<ClipWithID> &clips)
{
        return compute_time_left(clips, 0, 0.0);
}

std::string format_duration(double t);

#endif  // !defined(_PLAYER_H)