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

   1 #ifndef _VIDEO_WIDGET_H
   2 #define _VIDEO_WIDGET_H 1
   3
   4 #include <QOpenGLWidget>
   5 #include <string>
   6 #include <atomic>
   7 #include <thread>
   8 #include <chrono>
   9 #include <deque>
  10
  11 extern "C" {
  12 #include <libavutil/pixfmt.h>
  13 #include <libavutil/rational.h>
  14 }
  15
  16 #include "ffmpeg_raii.h"
  17 #include "quittable_sleeper.h"
  18
  19 // Because QVideoWidget sucks, sadly. (Don't use GStreamer, kids.)
  20
  21 class VideoWidget : public QOpenGLWidget {
  22         Q_OBJECT
  23
  24 public:
  25         VideoWidget(QWidget *parent);
  26         ~VideoWidget() { stop(); }
  27
  28         bool open(const std::string &filename);  // False on error.
  29         void play();
  30         uint64_t get_position() const { return last_position; }  // In milliseconds.
  31         void pause();
  32         void stop();
  33         void seek(int64_t relative_seek_ms);  // Relative seek.
  34         void seek_frames(int64_t relative_frames);  // Relative seek.
  35         void seek_absolute(int64_t position_ms);  // Absolute seek.
  36
  37         void initializeGL() override;
  38         void resizeGL(int w, int h) override;
  39         void paintGL() override;
  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         GLuint ycbcr_vertex_shader, ycbcr_fragment_shader, ycbcr_program;
  73         GLuint bilinear_sampler;
  74
  75         GLuint tex[3];
  76         GLuint last_width = 0, last_height = 0;
  77         GLuint last_chroma_width = 0, last_chroma_height = 0;
  78         GLfloat cbcr_offset[2];
  79         double display_aspect = 1.0;
  80         double zoom_matrix[9] = {  // Column-major, to match with OpenGL.
  81                 1.0, 0.0, 0.0,
  82                 0.0, 1.0, 0.0,
  83                 0.0, 0.0, 1.0,
  84         };
  85
  86         int64_t pts_origin;
  87         int64_t last_pts;
  88         std::atomic<uint64_t> last_position{0};  // TODO: sort of redundant wrt. last_pts (but this one can be read from the other thread)
  89         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.
  90         std::atomic<RunState> running{NOT_RUNNING};
  91         bool paused = false;
  92         std::chrono::steady_clock::time_point start, next_frame_start, last_frame;
  93
  94         SwsContextWithDeleter sws_ctx;
  95         int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
  96         AVPixelFormat sws_dst_format = AVPixelFormat(-1);  // In practice, always initialized.
  97         AVRational video_timebase, audio_timebase;
  98
  99         QuittableSleeper producer_thread_should_quit;
 100         std::thread producer_thread;
 101
 102         std::mutex queue_mu;
 103         struct QueuedCommand {
 104                 enum Command { PAUSE, RESUME, SEEK, SEEK_ABSOLUTE } command;
 105                 int64_t relative_seek_ms;  // For SEEK.
 106                 int64_t relative_seek_frames;  // For SEEK.
 107                 int64_t seek_ms;  // For SEEK_ABSOLUTE.
 108         };
 109         std::vector<QueuedCommand> command_queue;  // Protected by <queue_mu>.
 110
 111         std::string pathname;
 112
 113         bool dragging = false;
 114         float last_drag_x, last_drag_y;
 115
 116         void producer_thread_func();
 117         bool play_video(const std::string &pathname);
 118         void internal_rewind();
 119         AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx,
 120                 const std::string &pathname, int video_stream_index,
 121                 bool *error);
 122         std::shared_ptr<Frame> make_video_frame(const AVFrame *frame);
 123         bool process_queued_commands(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, int video_stream_index, bool *seeked);
 124         void store_pts(int64_t pts);
 125
 126         void fixup_zoom_matrix();
 127 };
 128
 129 #endif  // !defined(_VIDEO_WIDGET_H)