FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format);
void place_rectangle(movit::Effect *resample_effect, movit::Effect *padding_effect, float x0, float y0, float x1, float y1);
void thread_func();
+ void schedule_audio_resampling_tasks(unsigned dropped_frames, int num_samples_per_frame, int length_per_frame);
void render_one_frame();
void send_audio_level_callback();
void audio_thread_func();