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 class QOpenGLFunctions_4_5_Compatibility;
  21
  22 // Because QVideoWidget sucks, sadly. (Don't use GStreamer, kids.)
  23
  24 class VideoWindow;
  25
  26 class VideoWidget : public QWidget {
  27         Q_OBJECT
  28
  29 public:
  30         VideoWidget(QWidget *parent);
  31         ~VideoWidget();
  32
  33         bool open(const std::string &filename);  // False on error.
  34         void play();
  35         uint64_t get_position() const { return last_position; }  // In milliseconds.
  36         void pause();
  37         void stop();
  38         void seek(int64_t relative_seek_ms);  // Relative seek.
  39         void seek_frames(int64_t relative_frames);  // Relative seek.
  40         void seek_absolute(int64_t position_ms);  // Absolute seek.
  41
  42         void wheelEvent(QWheelEvent *event) override;
  43
  44         // For dragging, and for back/forward button presses.
  45         void mousePressEvent(QMouseEvent *e);
  46         void mouseReleaseEvent(QMouseEvent *e);
  47         void mouseMoveEvent(QMouseEvent *e);
  48
  49         // Public due to shared_ptr.
  50         struct Frame {
  51                 unsigned width, height;
  52                 unsigned chroma_width, chroma_height;
  53                 VideoWidget *owner;  // For the freelist.
  54                 GLuint pbo;
  55                 uint8_t *data;  // Persistently mapped into the PBO. Y, followed by Cb, followed by Cr.
  56                 size_t need_flush_len;  // 0 = no flush needed.
  57         };
  58
  59 signals:
  60         void position_changed(uint64_t pos);
  61         void mouse_back_clicked();
  62         void mouse_forward_clicked();
  63
  64 private:
  65         std::shared_ptr<Frame> alloc_frame(unsigned width, unsigned height, unsigned chroma_width, unsigned chroma_height);
  66         static void free_frame(Frame *frame);
  67
  68         std::mutex current_frame_mu;
  69         std::shared_ptr<Frame> current_frame;  // Protected by current_frame_mu.
  70         std::mutex freelist_mu;
  71         std::deque<Frame *> frame_freelist;  // Protected by freelist_mu.
  72         std::deque<AVFrameWithDeleter> queued_frames;  // Frames decoded but not displayed. Only used when frame-stepping backwards.
  73
  74         double zoom_matrix[9] = {  // Column-major, to match with OpenGL.
  75                 1.0, 0.0, 0.0,
  76                 0.0, 1.0, 0.0,
  77                 0.0, 0.0, 1.0,
  78         };
  79
  80         int64_t pts_origin;
  81         int64_t last_pts;
  82         std::atomic<uint64_t> last_position{0};  // TODO: sort of redundant wrt. last_pts (but this one can be read from the other thread)
  83         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.
  84         std::atomic<RunState> running{NOT_RUNNING};
  85         bool paused = false;
  86         std::chrono::steady_clock::time_point start, next_frame_start, last_frame;
  87
  88         SwsContextWithDeleter sws_ctx;
  89         int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
  90         AVPixelFormat sws_dst_format = AVPixelFormat(-1);  // In practice, always initialized.
  91         AVRational video_timebase, audio_timebase;
  92
  93         QuittableSleeper producer_thread_should_quit;
  94         std::thread producer_thread;
  95
  96         std::mutex queue_mu;
  97         struct QueuedCommand {
  98                 enum Command { PAUSE, RESUME, SEEK, SEEK_ABSOLUTE } command;
  99                 int64_t relative_seek_ms;  // For SEEK.
 100                 int64_t relative_seek_frames;  // For SEEK.
 101                 int64_t seek_ms;  // For SEEK_ABSOLUTE.
 102         };
 103         std::vector<QueuedCommand> command_queue;  // Protected by <queue_mu>.
 104
 105         std::string pathname;
 106
 107         bool dragging = false;
 108         float last_drag_x, last_drag_y;
 109
 110         VideoWindow *video_window;
 111
 112         void producer_thread_func();
 113         bool play_video(const std::string &pathname);
 114         void internal_rewind();
 115         AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx,
 116                 const std::string &pathname, int video_stream_index,
 117                 bool *error);
 118         std::shared_ptr<Frame> make_video_frame(const AVFrame *frame);
 119         bool process_queued_commands(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, int video_stream_index, bool *seeked);
 120         void store_pts(int64_t pts);
 121
 122         void fixup_zoom_matrix();
 123 };
 124
 125 class VideoWindow : public QOpenGLWindow {  // Private implementation of VideoWidget, but moc does not support nested classes.
 126         Q_OBJECT;
 127
 128 public:
 129         VideoWindow(VideoWidget *video) : video(video) {}
 130         void initializeGL() override;
 131         void resizeGL(int w, int h) override;
 132         void paintGL() override;
 133         void set_current_frame(std::shared_ptr<VideoWidget::Frame> new_frame);  // Takes ownership. Thread-safe.
 134         void set_cbcr_offset(float x, float y)  // FIXME: Thread-safe?
 135         {
 136                 cbcr_offset[0] = x;
 137                 cbcr_offset[1] = y;
 138         }
 139         void set_zoom_matrix(double new_zoom_matrix[9]) {
 140                 memcpy(zoom_matrix, new_zoom_matrix, sizeof(zoom_matrix));
 141                 update();
 142         }
 143
 144         void wheelEvent(QWheelEvent *e) override { emit mouse_wheel(e); }
 145         void mousePressEvent(QMouseEvent *e) override { emit mouse_pressed(e); }
 146         void mouseReleaseEvent(QMouseEvent *e) override { emit mouse_released(e); }
 147         void mouseMoveEvent(QMouseEvent *e) override { emit mouse_moved(e); }
 148
 149 signals:
 150         void mouse_wheel(QWheelEvent *e);
 151         void mouse_pressed(QMouseEvent *e);
 152         void mouse_released(QMouseEvent *e);
 153         void mouse_moved(QMouseEvent *e);
 154
 155 private:
 156         QOpenGLFunctions_4_5_Compatibility *gl = nullptr;
 157         VideoWidget *video;
 158         GLuint ycbcr_vertex_shader, ycbcr_fragment_shader, ycbcr_program;
 159         GLuint bilinear_sampler;
 160         GLuint tex[3];
 161         GLuint last_width = 0, last_height = 0;
 162         GLuint last_chroma_width = 0, last_chroma_height = 0;
 163         double display_aspect = 1.0;
 164         GLfloat cbcr_offset[2];
 165
 166         double zoom_matrix[9] = {  // Column-major, to match with OpenGL.
 167                 1.0, 0.0, 0.0,
 168                 0.0, 1.0, 0.0,
 169                 0.0, 0.0, 1.0,
 170         };
 171
 172         std::mutex current_frame_mu;
 173         std::shared_ptr<VideoWidget::Frame> current_frame;  // Protected by current_frame_mu.
 174 };
 175
 176 #endif  // !defined(_VIDEO_WIDGET_H)