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         void open(const std::string &filename);
  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 signals:
  48         void position_changed(uint64_t pos);
  49         void mouse_back_clicked();
  50         void mouse_forward_clicked();
  51
  52 private:
  53         // Should really have been persistent and a PBO, but this is OK for now.
  54         struct Frame {
  55                 unsigned width, height;
  56                 unsigned chroma_width, chroma_height;
  57                 std::unique_ptr<uint8_t[]> data;  // Y, followed by Cb, followed by Cr.
  58         };
  59         std::mutex current_frame_mu;
  60         std::shared_ptr<Frame> current_frame;  // Protected by current_frame_mu.
  61         std::deque<AVFrameWithDeleter> queued_frames;  // Frames decoded but not displayed. Only used when frame-stepping backwards.
  62
  63         GLuint ycbcr_vertex_shader, ycbcr_fragment_shader, ycbcr_program;
  64         GLuint bilinear_sampler;
  65
  66         GLuint tex[3];
  67         GLuint last_width = 0, last_height = 0;
  68         GLuint last_chroma_width = 0, last_chroma_height = 0;
  69         GLfloat cbcr_offset[2];
  70         double display_aspect = 1.0;
  71         double zoom_matrix[9] = {  // Column-major, to match with OpenGL.
  72                 1.0, 0.0, 0.0,
  73                 0.0, 1.0, 0.0,
  74                 0.0, 0.0, 1.0,
  75         };
  76
  77         int64_t pts_origin;
  78         int64_t last_pts;
  79         std::atomic<uint64_t> last_position{0};  // TODO: sort of redundant wrt. last_pts (but this one can be read from the other thread)
  80         std::atomic<bool> running{false};
  81         bool paused = false;
  82         std::chrono::steady_clock::time_point start, next_frame_start, last_frame;
  83
  84         SwsContextWithDeleter sws_ctx;
  85         int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
  86         AVPixelFormat sws_dst_format = AVPixelFormat(-1);  // In practice, always initialized.
  87         AVRational video_timebase, audio_timebase;
  88
  89         QuittableSleeper producer_thread_should_quit;
  90         std::thread producer_thread;
  91
  92         std::mutex queue_mu;
  93         struct QueuedCommand {
  94                 enum Command { PAUSE, RESUME, SEEK, SEEK_ABSOLUTE } command;
  95                 int64_t relative_seek_ms;  // For SEEK.
  96                 int64_t relative_seek_frames;  // For SEEK.
  97                 int64_t seek_ms;  // For SEEK_ABSOLUTE.
  98         };
  99         std::vector<QueuedCommand> command_queue;  // Protected by <queue_mu>.
 100
 101         std::string pathname;
 102
 103         bool dragging = false;
 104         float last_drag_x, last_drag_y;
 105
 106         void producer_thread_func();
 107         bool play_video(const std::string &pathname);
 108         void internal_rewind();
 109         AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx,
 110                 const std::string &pathname, int video_stream_index,
 111                 bool *error);
 112         Frame make_video_frame(const AVFrame *frame);
 113         bool process_queued_commands(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, int video_stream_index, bool *seeked);
 114         void store_pts(int64_t pts);
 115
 116         void fixup_zoom_matrix();
 117 };
 118
 119 #endif  // !defined(_VIDEO_WIDGET_H)