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 signals:
  43         void position_changed(uint64_t pos);
  44
  45 private:
  46         // Should really have been persistent and a PBO, but this is OK for now.
  47         struct Frame {
  48                 unsigned width, height;
  49                 unsigned chroma_width, chroma_height;
  50                 std::unique_ptr<uint8_t[]> data;  // Y, followed by Cb, followed by Cr.
  51         };
  52         std::shared_ptr<Frame> current_frame;
  53         std::deque<AVFrameWithDeleter> queued_frames;  // Frames decoded but not displayed. Only used when frame-stepping backwards.
  54
  55         GLuint ycbcr_vertex_shader, ycbcr_fragment_shader, ycbcr_program;
  56         GLuint bilinear_sampler;
  57
  58         GLuint tex[3];
  59         GLuint last_width = 0, last_height = 0;
  60         GLuint last_chroma_width = 0, last_chroma_height = 0;
  61         GLfloat cbcr_offset[2];
  62         double display_aspect = 1.0;
  63         double zoom_matrix[9] = {  // Column-major, to match with OpenGL.
  64                 1.0, 0.0, 0.0,
  65                 0.0, 1.0, 0.0,
  66                 0.0, 0.0, 1.0,
  67         };
  68
  69         int64_t pts_origin;
  70         int64_t last_pts;
  71         std::atomic<uint64_t> last_position{0};  // TODO: sort of redundant wrt. last_pts (but this one can be read from the other thread)
  72         std::atomic<bool> running{false};
  73         bool paused = false;
  74         std::chrono::steady_clock::time_point start, next_frame_start, last_frame;
  75
  76         SwsContextWithDeleter sws_ctx;
  77         int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
  78         AVPixelFormat sws_dst_format = AVPixelFormat(-1);  // In practice, always initialized.
  79         AVRational video_timebase, audio_timebase;
  80
  81         QuittableSleeper producer_thread_should_quit;
  82         std::thread producer_thread;
  83
  84         std::mutex queue_mu;
  85         struct QueuedCommand {
  86                 enum Command { PAUSE, RESUME, SEEK, SEEK_ABSOLUTE } command;
  87                 int64_t relative_seek_ms;  // For SEEK.
  88                 int64_t relative_seek_frames;  // For SEEK.
  89                 int64_t seek_ms;  // For SEEK_ABSOLUTE.
  90         };
  91         std::vector<QueuedCommand> command_queue;  // Protected by <queue_mu>.
  92
  93         std::string pathname;
  94
  95         void producer_thread_func();
  96         bool play_video(const std::string &pathname);
  97         void internal_rewind();
  98         AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx,
  99                 const std::string &pathname, int video_stream_index,
 100                 bool *error);
 101         Frame make_video_frame(const AVFrame *frame);
 102         bool process_queued_commands(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, int video_stream_index, bool *seeked);
 103         void store_pts(int64_t pts);
 104
 105         void fixup_zoom_matrix();
 106 };
 107
 108 #endif  // !defined(_VIDEO_WIDGET_H)