git.sesse.net Git - pkanalytics/blob - video_widget.h

   1 #ifndef _VIDEO_WIDGET_H
   2 #define _VIDEO_WIDGET_H 1
   3
   4 #include <QWidget>
   5 #include <QOpenGLWindow>
   6 #include <string>
   7 #include <atomic>
   8 #include <thread>
   9 #include <chrono>
  10 #include <deque>
  11
  12 extern "C" {
  13 #include <libavutil/pixfmt.h>
  14 #include <libavutil/rational.h>
  15 }
  16
  17 #include "ffmpeg_raii.h"
  18 #include "quittable_sleeper.h"
  19
  20 // Because QVideoWidget sucks, sadly. (Don't use GStreamer, kids.)
  21
  22 class VideoWindow;
  23
  24 class VideoWidget : public QWidget {
  25         Q_OBJECT
  26
  27 public:
  28         VideoWidget(QWidget *parent);
  29         ~VideoWidget() { stop(); }
  30
  31         bool open(const std::string &filename);  // False on error.
  32         void play();
  33         uint64_t get_position() const { return last_position; }  // In milliseconds.
  34         void pause();
  35         void stop();
  36         void seek(int64_t relative_seek_ms);  // Relative seek.
  37         void seek_frames(int64_t relative_frames);  // Relative seek.
  38         void seek_absolute(int64_t position_ms);  // Absolute seek.
  39
  40         void wheelEvent(QWheelEvent *event) override;
  41
  42         // For dragging, and for back/forward button presses.
  43         void mousePressEvent(QMouseEvent *e);
  44         void mouseReleaseEvent(QMouseEvent *e);
  45         void mouseMoveEvent(QMouseEvent *e);
  46
  47         // Public due to shared_ptr.
  48         struct Frame {
  49                 unsigned width, height;
  50                 unsigned chroma_width, chroma_height;
  51                 VideoWidget *owner;  // For the freelist.
  52                 GLuint pbo;
  53                 uint8_t *data;  // Persistently mapped into the PBO. Y, followed by Cb, followed by Cr.
  54                 size_t need_flush_len;  // 0 = no flush needed.
  55         };
  56
  57 signals:
  58         void position_changed(uint64_t pos);
  59         void mouse_back_clicked();
  60         void mouse_forward_clicked();
  61
  62 private:
  63         std::shared_ptr<Frame> alloc_frame(unsigned width, unsigned height, unsigned chroma_width, unsigned chroma_height);
  64         static void free_frame(Frame *frame);
  65
  66         std::mutex current_frame_mu;
  67         std::shared_ptr<Frame> current_frame;  // Protected by current_frame_mu.
  68         std::mutex freelist_mu;
  69         std::deque<Frame *> frame_freelist;  // Protected by freelist_mu.
  70         std::deque<AVFrameWithDeleter> queued_frames;  // Frames decoded but not displayed. Only used when frame-stepping backwards.
  71
  72         double zoom_matrix[9] = {  // Column-major, to match with OpenGL.
  73                 1.0, 0.0, 0.0,
  74                 0.0, 1.0, 0.0,
  75                 0.0, 0.0, 1.0,
  76         };
  77
  78         int64_t pts_origin;
  79         int64_t last_pts;
  80         std::atomic<uint64_t> last_position{0};  // TODO: sort of redundant wrt. last_pts (but this one can be read from the other thread)
  81         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.
  82         std::atomic<RunState> running{NOT_RUNNING};
  83         bool paused = false;
  84         std::chrono::steady_clock::time_point start, next_frame_start, last_frame;
  85
  86         SwsContextWithDeleter sws_ctx;
  87         int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
  88         AVPixelFormat sws_dst_format = AVPixelFormat(-1);  // In practice, always initialized.
  89         AVRational video_timebase, audio_timebase;
  90
  91         QuittableSleeper producer_thread_should_quit;
  92         std::thread producer_thread;
  93
  94         std::mutex queue_mu;
  95         struct QueuedCommand {
  96                 enum Command { PAUSE, RESUME, SEEK, SEEK_ABSOLUTE } command;
  97                 int64_t relative_seek_ms;  // For SEEK.
  98                 int64_t relative_seek_frames;  // For SEEK.
  99                 int64_t seek_ms;  // For SEEK_ABSOLUTE.
 100         };
 101         std::vector<QueuedCommand> command_queue;  // Protected by <queue_mu>.
 102
 103         std::string pathname;
 104
 105         bool dragging = false;
 106         float last_drag_x, last_drag_y;
 107
 108         VideoWindow *video_window;
 109
 110         void producer_thread_func();
 111         bool play_video(const std::string &pathname);
 112         void internal_rewind();
 113         AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx,
 114                 const std::string &pathname, int video_stream_index,
 115                 bool *error);
 116         std::shared_ptr<Frame> make_video_frame(const AVFrame *frame);
 117         bool process_queued_commands(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, int video_stream_index, bool *seeked);
 118         void store_pts(int64_t pts);
 119
 120         void fixup_zoom_matrix();
 121 };
 122
 123 class VideoWindow : public QOpenGLWindow {  // Private implementation of VideoWidget, but moc does not support nested classes.
 124         Q_OBJECT;
 125
 126 public:
 127         VideoWindow(VideoWidget *video) : video(video) {}
 128         void initializeGL() override;
 129         void resizeGL(int w, int h) override;
 130         void paintGL() override;
 131         void set_current_frame(std::shared_ptr<VideoWidget::Frame> new_frame);  // Takes ownership. Thread-safe.
 132         void set_cbcr_offset(float x, float y)  // FIXME: Thread-safe?
 133         {
 134                 cbcr_offset[0] = x;
 135                 cbcr_offset[1] = y;
 136         }
 137         void set_zoom_matrix(double new_zoom_matrix[9]) {
 138                 memcpy(zoom_matrix, new_zoom_matrix, sizeof(zoom_matrix));
 139                 update();
 140         }
 141
 142         void wheelEvent(QWheelEvent *e) override { emit mouse_wheel(e); }
 143         void mousePressEvent(QMouseEvent *e) override { emit mouse_pressed(e); }
 144         void mouseReleaseEvent(QMouseEvent *e) override { emit mouse_released(e); }
 145         void mouseMoveEvent(QMouseEvent *e) override { emit mouse_moved(e); }
 146
 147 signals:
 148         void mouse_wheel(QWheelEvent *e);
 149         void mouse_pressed(QMouseEvent *e);
 150         void mouse_released(QMouseEvent *e);
 151         void mouse_moved(QMouseEvent *e);
 152
 153 private:
 154         VideoWidget *video;
 155         GLuint ycbcr_vertex_shader, ycbcr_fragment_shader, ycbcr_program;
 156         GLuint bilinear_sampler;
 157         GLuint tex[3];
 158         GLuint last_width = 0, last_height = 0;
 159         GLuint last_chroma_width = 0, last_chroma_height = 0;
 160         double display_aspect = 1.0;
 161         GLfloat cbcr_offset[2];
 162
 163         double zoom_matrix[9] = {  // Column-major, to match with OpenGL.
 164                 1.0, 0.0, 0.0,
 165                 0.0, 1.0, 0.0,
 166                 0.0, 0.0, 1.0,
 167         };
 168
 169         std::mutex current_frame_mu;
 170         std::shared_ptr<VideoWidget::Frame> current_frame;  // Protected by current_frame_mu.
 171 };
 172
 173 #endif  // !defined(_VIDEO_WIDGET_H)