+#ifndef _MIXER_H
+#define _MIXER_H 1
+
+// The actual video mixer, running in its own separate background thread.
+
+#include <epoxy/gl.h>
+#undef Success
+#include <movit/effect_chain.h>
+#include <functional>
+
+#include "bmusb.h"
+#include "h264encode.h"
+#include "pbo_frame_allocator.h"
+#include "ref_counted_gl_sync.h"
+
+#define NUM_CARDS 2
+
+namespace movit {
+class YCbCrInput;
+}
+class QOpenGLContext;
class QSurface;
-void start_mixer(QSurface *surface, QSurface *surface2, QSurface *surface3, QSurface *surface4);
-void mixer_quit();
+
+class Mixer {
+public:
+ // The surfaces are used for offscreen destinations for OpenGL contexts we need.
+ // TODO: Figure out something slightly more generic.
+ Mixer(QSurface *surface1, QSurface *surface2, QSurface *surface3, QSurface *surface4);
+ ~Mixer();
+ void start();
+ void quit();
+
+ enum Source {
+ SOURCE_INPUT1,
+ SOURCE_INPUT2,
+ SOURCE_SBS,
+ };
+ void cut(Source source);
+
+ struct DisplayFrame {
+ GLuint texnum;
+ RefCountedGLsync ready_fence; // Asserted when the texture is done rendering.
+ };
+ // Implicitly frees the previous one if there's a new frame available.
+ bool get_display_frame(DisplayFrame *frame);
+
+ typedef std::function<void()> new_frame_ready_callback_t;
+ void set_frame_ready_fallback(new_frame_ready_callback_t callback);
+
+private:
+ void bm_frame(int card_index, uint16_t timecode,
+ FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
+ FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format);
+ void place_rectangle(movit::Effect *resample_effect, movit::Effect *padding_effect, float x0, float y0, float x1, float y1);
+ void thread_func();
+
+ std::unique_ptr<PBOFrameAllocator> pbo_allocator1, pbo_allocator2;
+
+ QSurface *surface1, *surface2, *surface3, *surface4;
+ std::unique_ptr<movit::EffectChain> chain;
+ movit::ResourcePool *resource_pool; // Owned by <chain>.
+ GLuint cbcr_program_num; // Owned by <resource_pool>.
+ std::unique_ptr<H264Encoder> h264_encoder;
+
+ // Effects part of <chain>. Owned by <chain>.
+ movit::YCbCrInput *input[NUM_CARDS];
+ movit::Effect *resample_effect, *resample2_effect;
+ movit::Effect *padding_effect, *padding2_effect;
+
+ Source current_source = SOURCE_INPUT1;
+ int frame = 0;
+
+ std::mutex display_frame_mutex;
+ DisplayFrame current_display_frame, ready_display_frame; // protected by <frame_mutex>
+ bool has_current_display_frame = false, has_ready_display_frame = false; // protected by <frame_mutex>
+
+ std::mutex bmusb_mutex;
+ struct CaptureCard {
+ BMUSBCapture *usb;
+
+ // Threading stuff
+ bool thread_initialized = false;
+ QSurface *surface;
+ QOpenGLContext *context;
+
+ bool new_data_ready = false; // Whether new_frame contains anything.
+ FrameAllocator::Frame new_frame;
+ GLsync new_data_ready_fence; // Whether new_frame is ready for rendering.
+ std::condition_variable new_data_ready_changed; // Set whenever new_data_ready is changed.
+ };
+ CaptureCard cards[NUM_CARDS]; // protected by <bmusb_mutex>
+
+ FrameAllocator::Frame bmusb_current_rendering_frame[NUM_CARDS];
+
+ new_frame_ready_callback_t new_frame_ready_callback;
+ bool has_new_frame_ready_callback = false;
+
+ std::thread mixer_thread;
+ bool should_quit = false;
+};
+
+extern Mixer *global_mixer;
+
+#endif // !defined(_MIXER_H)