Make Frame allocated on a freelist, in preparation for PBOs.

[pkanalytics] / video_widget.h

diff --git a/video_widget.h b/video_widget.h
index 56cf92862605d41b82e56caf90f9d834c4ec64e7..24aaea3b6a8129e179ff6c7c23343b7dc4872874 100644 (file)
--- a/video_widget.h
+++ b/video_widget.h
@@ -25,7 +25,7 @@ public:
        VideoWidget(QWidget *parent);
        ~VideoWidget() { stop(); }
 
-       void open(const std::string &filename);
+       bool open(const std::string &filename);  // False on error.
        void play();
        uint64_t get_position() const { return last_position; }  // In milliseconds.
        void pause();
@@ -39,22 +39,33 @@ public:
        void paintGL() override;
        void wheelEvent(QWheelEvent *event) override;
 
-       // For dragging.
+       // For dragging, and for back/forward button presses.
        void mousePressEvent(QMouseEvent *e);
        void mouseReleaseEvent(QMouseEvent *e);
        void mouseMoveEvent(QMouseEvent *e);
 
-signals:
-       void position_changed(uint64_t pos);
-
-private:
-       // Should really have been persistent and a PBO, but this is OK for now.
+       // Should really have a PBO, but this is OK for now.
+       // public due to shared_ptr.
        struct Frame {
                unsigned width, height;
                unsigned chroma_width, chroma_height;
                std::unique_ptr<uint8_t[]> data;  // Y, followed by Cb, followed by Cr.
+               VideoWidget *owner;  // For the freelist.
        };
-       std::shared_ptr<Frame> current_frame;
+
+signals:
+       void position_changed(uint64_t pos);
+       void mouse_back_clicked();
+       void mouse_forward_clicked();
+
+private:
+       std::shared_ptr<Frame> alloc_frame(unsigned width, unsigned height, unsigned chroma_width, unsigned chroma_height);
+       static void free_frame(Frame *frame);
+
+       std::mutex current_frame_mu;
+       std::shared_ptr<Frame> current_frame;  // Protected by current_frame_mu.
+       std::mutex freelist_mu;
+       std::deque<Frame *> frame_freelist;  // Protected by freelist_mu.
        std::deque<AVFrameWithDeleter> queued_frames;  // Frames decoded but not displayed. Only used when frame-stepping backwards.
 
        GLuint ycbcr_vertex_shader, ycbcr_fragment_shader, ycbcr_program;
@@ -74,7 +85,8 @@ private:
        int64_t pts_origin;
        int64_t last_pts;
        std::atomic<uint64_t> last_position{0};  // TODO: sort of redundant wrt. last_pts (but this one can be read from the other thread)
-       std::atomic<bool> running{false};
+       enum RunState { NOT_RUNNING, STARTING, RUNNING, VIDEO_FILE_ERROR };  // NOT_RUNNING and VIDEO_FILE_ERROR both imply that the thread isn't running and can freely be restarted.
+       std::atomic<RunState> running{NOT_RUNNING};
        bool paused = false;
        std::chrono::steady_clock::time_point start, next_frame_start, last_frame;
 
@@ -106,7 +118,7 @@ private:
        AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx,
                const std::string &pathname, int video_stream_index,
                bool *error);
-       Frame make_video_frame(const AVFrame *frame);
+       std::shared_ptr<Frame> make_video_frame(const AVFrame *frame);
        bool process_queued_commands(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, int video_stream_index, bool *seeked);
        void store_pts(int64_t pts);