Prepare get_one_frame_from_each_card() interface for different clocks.

[nageru] / mixer.cpp

diff --git a/mixer.cpp b/mixer.cpp
index a4ae1aab50c1a68baf623a03ce04b8990c158554..db7a060ce392aae209b38d94cfc95ec60d73cf09 100644 (file)
--- a/mixer.cpp
+++ b/mixer.cpp
@@ -186,9 +186,8 @@ Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
        BMUSBCapture::set_card_connected_callback(bind(&Mixer::bm_hotplug_add, this, _1));
        BMUSBCapture::start_bm_thread();
 
-       for (card_index = 0; card_index < num_cards; ++card_index) {
+       for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
                cards[card_index].queue_length_policy.reset(card_index);
-               cards[card_index].capture->start_bm_capture();
        }
 
        // Set up stuff for NV12 conversion.
@@ -331,7 +330,6 @@ void Mixer::configure_card(unsigned card_index, CaptureInterface *capture, bool
                card->surface = create_surface_with_same_format(mixer_surface);
        }
        while (!card->new_frames.empty()) card->new_frames.pop();
-       card->fractional_samples = 0;
        card->last_timecode = -1;
        card->capture->configure_card();
 
@@ -592,6 +590,12 @@ void Mixer::thread_func()
                exit(1);
        }
 
+       // Start the actual capture. (We don't want to do it before we're actually ready
+       // to process output frames.)
+       for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
+               cards[card_index].capture->start_bm_capture();
+       }
+
        steady_clock::time_point start, now;
        start = steady_clock::now();
 
@@ -601,14 +605,13 @@ void Mixer::thread_func()
        while (!should_quit) {
                CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS];
                bool has_new_frame[MAX_VIDEO_CARDS] = { false };
-               int num_samples[MAX_VIDEO_CARDS] = { 0 };
 
                unsigned master_card_index = theme->map_signal(master_clock_channel);
                assert(master_card_index < num_cards);
 
-               get_one_frame_from_each_card(master_card_index, new_frames, has_new_frame, num_samples);
-               schedule_audio_resampling_tasks(new_frames[master_card_index].dropped_frames, num_samples[master_card_index], new_frames[master_card_index].length);
-               stats_dropped_frames += new_frames[master_card_index].dropped_frames;
+               OutputFrameInfo output_frame_info = get_one_frame_from_each_card(master_card_index, new_frames, has_new_frame);
+               schedule_audio_resampling_tasks(output_frame_info.dropped_frames, output_frame_info.num_samples, output_frame_info.frame_duration);
+               stats_dropped_frames += output_frame_info.dropped_frames;
 
                handle_hotplugged_cards();
 
@@ -649,7 +652,7 @@ void Mixer::thread_func()
                        }
                }
 
-               int64_t frame_duration = new_frames[master_card_index].length;
+               int64_t frame_duration = output_frame_info.frame_duration;
                render_one_frame(frame_duration);
                ++frame;
                pts_int += frame_duration;
@@ -710,8 +713,10 @@ void Mixer::thread_func()
        resource_pool->clean_context();
 }
 
-void Mixer::get_one_frame_from_each_card(unsigned master_card_index, CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS], bool has_new_frame[MAX_VIDEO_CARDS], int num_samples[MAX_VIDEO_CARDS])
+Mixer::OutputFrameInfo Mixer::get_one_frame_from_each_card(unsigned master_card_index, CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS], bool has_new_frame[MAX_VIDEO_CARDS])
 {
+       OutputFrameInfo output_frame_info;
+
 start:
        // The first card is the master timer, so wait for it to have a new frame.
        // TODO: Add a timeout.
@@ -738,11 +743,6 @@ start:
                card->new_frames.pop();
                card->new_frames_changed.notify_all();
 
-               int num_samples_times_timebase = OUTPUT_FREQUENCY * new_frames[card_index].length + card->fractional_samples;
-               num_samples[card_index] = num_samples_times_timebase / TIMEBASE;
-               card->fractional_samples = num_samples_times_timebase % TIMEBASE;
-               assert(num_samples[card_index] >= 0);
-
                if (card_index == master_card_index) {
                        // We don't use the queue length policy for the master card,
                        // but we will if it stops being the master. Thus, clear out
@@ -757,6 +757,18 @@ start:
                        }
                }
        }
+
+       output_frame_info.dropped_frames = new_frames[master_card_index].dropped_frames;
+       output_frame_info.frame_duration = new_frames[master_card_index].length;
+
+       // This might get off by a fractional sample when changing master card
+       // between ones with different frame rates, but that's fine.
+       int num_samples_times_timebase = OUTPUT_FREQUENCY * output_frame_info.frame_duration + fractional_samples;
+       output_frame_info.num_samples = num_samples_times_timebase / TIMEBASE;
+       fractional_samples = num_samples_times_timebase % TIMEBASE;
+       assert(output_frame_info.num_samples >= 0);
+
+       return output_frame_info;
 }
 
 void Mixer::handle_hotplugged_cards()
@@ -870,7 +882,7 @@ void Mixer::render_one_frame(int64_t duration)
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 
-       const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampling_queue.h. TODO: Make less hard-coded.
+       const int64_t av_delay = lrint(global_flags.audio_queue_length_ms * 0.001 * TIMEBASE);  // Corresponds to the delay in ResamplingQueue.
        RefCountedGLsync fence = video_encoder->end_frame(pts_int + av_delay, duration, theme_main_chain.input_frames);
 
        // The live frame just shows the RGBA texture we just rendered.