4 // The actual video mixer, running in its own separate background thread.
10 #include <movit/effect_chain.h>
11 #include <movit/flat_input.h>
14 #include <zita-resampler/resampler.h>
18 #include <condition_variable>
29 #include "alsa_output.h"
30 #include "audio_mixer.h"
31 #include "bmusb/bmusb.h"
32 #include "correlation_measurer.h"
34 #include "ebu_r128_proc.h"
36 #include "input_state.h"
37 #include "pbo_frame_allocator.h"
38 #include "ref_counted_frame.h"
39 #include "ref_counted_gl_sync.h"
40 #include "resampling_queue.h"
43 #include "stereocompressor.h"
44 #include "video_encoder.h"
48 class QuickSyncEncoder;
61 // For any card that's not the master (where we pick out the frames as they
62 // come, as fast as we can process), there's going to be a queue. The question
63 // is when we should drop frames from that queue (apart from the obvious
64 // dropping if the 16-frame queue should become full), especially given that
65 // the frame rate could be lower or higher than the master (either subtly or
66 // dramatically). We have two (conflicting) demands:
68 // 1. We want to avoid starving the queue.
69 // 2. We don't want to add more delay than is needed.
71 // Our general strategy is to drop as many frames as we can (helping for #2)
72 // that we think is safe for #1 given jitter. To this end, we set a lower floor N,
73 // where we assume that if we have N frames in the queue, we're always safe from
74 // starvation. (Typically, N will be 0 or 1. It starts off at 0.) If we have
75 // more than N frames in the queue after reading out the one we need, we head-drop
76 // them to reduce the queue.
78 // N is reduced as follows: If the queue has had at least one spare frame for
79 // at least 50 (master) frames (ie., it's been too conservative for a second),
80 // we reduce N by 1 and reset the timers. TODO: Only do this if N ever actually
83 // Whenever the queue is starved (we needed a frame but there was none),
84 // and we've been at N since the last starvation, N was obviously too low,
85 // so we increment it. We will never set N above 5, though.
86 class QueueLengthPolicy {
88 QueueLengthPolicy() {}
89 void reset(unsigned card_index) {
90 this->card_index = card_index;
91 safe_queue_length = 0;
92 frames_with_at_least_one = 0;
93 been_at_safe_point_since_last_starvation = false;
96 void update_policy(int queue_length); // Give in -1 for starvation.
97 unsigned get_safe_queue_length() const { return safe_queue_length; }
100 unsigned card_index; // For debugging only.
101 unsigned safe_queue_length = 0; // Called N in the comments.
102 unsigned frames_with_at_least_one = 0;
103 bool been_at_safe_point_since_last_starvation = false;
108 // The surface format is used for offscreen destinations for OpenGL contexts we need.
109 Mixer(const QSurfaceFormat &format, unsigned num_cards);
114 void transition_clicked(int transition_num);
115 void channel_clicked(int preview_num);
120 OUTPUT_INPUT0, // 1, 2, 3, up to 15 follow numerically.
124 struct DisplayFrame {
125 // The chain for rendering this frame. To render a display frame,
126 // first wait for <ready_fence>, then call <setup_chain>
127 // to wire up all the inputs, and then finally call
128 // chain->render_to_screen() or similar.
129 movit::EffectChain *chain;
130 std::function<void()> setup_chain;
132 // Asserted when all the inputs are ready; you cannot render the chain
134 RefCountedGLsync ready_fence;
136 // Holds on to all the input frames needed for this display frame,
137 // so they are not released while still rendering.
138 std::vector<RefCountedFrame> input_frames;
140 // Textures that should be released back to the resource pool
141 // when this frame disappears, if any.
142 // TODO: Refcount these as well?
143 std::vector<GLuint> temp_textures;
145 // Implicitly frees the previous one if there's a new frame available.
146 bool get_display_frame(Output output, DisplayFrame *frame) {
147 return output_channel[output].get_display_frame(frame);
150 typedef std::function<void()> new_frame_ready_callback_t;
151 void set_frame_ready_callback(Output output, new_frame_ready_callback_t callback)
153 output_channel[output].set_frame_ready_callback(callback);
156 // TODO: Should this really be per-channel? Shouldn't it just be called for e.g. the live output?
157 typedef std::function<void(const std::vector<std::string> &)> transition_names_updated_callback_t;
158 void set_transition_names_updated_callback(Output output, transition_names_updated_callback_t callback)
160 output_channel[output].set_transition_names_updated_callback(callback);
163 typedef std::function<void(const std::string &)> name_updated_callback_t;
164 void set_name_updated_callback(Output output, name_updated_callback_t callback)
166 output_channel[output].set_name_updated_callback(callback);
169 typedef std::function<void(const std::string &)> color_updated_callback_t;
170 void set_color_updated_callback(Output output, color_updated_callback_t callback)
172 output_channel[output].set_color_updated_callback(callback);
175 typedef std::function<void(float level_lufs, float peak_db,
176 float global_level_lufs, float range_low_lufs, float range_high_lufs,
177 float gain_staging_db, float final_makeup_gain_db,
178 float correlation)> audio_level_callback_t;
179 void set_audio_level_callback(audio_level_callback_t callback)
181 audio_level_callback = callback;
184 std::vector<std::string> get_transition_names()
186 return theme->get_transition_names(pts());
189 unsigned get_num_channels() const
191 return theme->get_num_channels();
194 std::string get_channel_name(unsigned channel) const
196 return theme->get_channel_name(channel);
199 std::string get_channel_color(unsigned channel) const
201 return theme->get_channel_color(channel);
204 int get_channel_signal(unsigned channel) const
206 return theme->get_channel_signal(channel);
209 int map_signal(unsigned channel)
211 return theme->map_signal(channel);
214 unsigned get_audio_source() const
216 return audio_source_channel;
219 void set_audio_source(unsigned channel)
221 audio_source_channel = channel;
224 unsigned get_master_clock() const
226 return master_clock_channel;
229 void set_master_clock(unsigned channel)
231 master_clock_channel = channel;
234 void set_signal_mapping(int signal, int card)
236 return theme->set_signal_mapping(signal, card);
239 bool get_supports_set_wb(unsigned channel) const
241 return theme->get_supports_set_wb(channel);
244 void set_wb(unsigned channel, double r, double g, double b) const
246 theme->set_wb(channel, r, g, b);
249 AudioMixer *get_audio_mixer() { return &audio_mixer; }
250 const AudioMixer *get_audio_mixer() const { return &audio_mixer; }
259 unsigned get_num_cards() const { return num_cards; }
261 std::string get_card_description(unsigned card_index) const {
262 assert(card_index < num_cards);
263 return cards[card_index].capture->get_description();
266 std::map<uint32_t, bmusb::VideoMode> get_available_video_modes(unsigned card_index) const {
267 assert(card_index < num_cards);
268 return cards[card_index].capture->get_available_video_modes();
271 uint32_t get_current_video_mode(unsigned card_index) const {
272 assert(card_index < num_cards);
273 return cards[card_index].capture->get_current_video_mode();
276 void set_video_mode(unsigned card_index, uint32_t mode) {
277 assert(card_index < num_cards);
278 cards[card_index].capture->set_video_mode(mode);
281 void start_mode_scanning(unsigned card_index);
283 std::map<uint32_t, std::string> get_available_video_inputs(unsigned card_index) const {
284 assert(card_index < num_cards);
285 return cards[card_index].capture->get_available_video_inputs();
288 uint32_t get_current_video_input(unsigned card_index) const {
289 assert(card_index < num_cards);
290 return cards[card_index].capture->get_current_video_input();
293 void set_video_input(unsigned card_index, uint32_t input) {
294 assert(card_index < num_cards);
295 cards[card_index].capture->set_video_input(input);
298 std::map<uint32_t, std::string> get_available_audio_inputs(unsigned card_index) const {
299 assert(card_index < num_cards);
300 return cards[card_index].capture->get_available_audio_inputs();
303 uint32_t get_current_audio_input(unsigned card_index) const {
304 assert(card_index < num_cards);
305 return cards[card_index].capture->get_current_audio_input();
308 void set_audio_input(unsigned card_index, uint32_t input) {
309 assert(card_index < num_cards);
310 cards[card_index].capture->set_audio_input(input);
313 void change_x264_bitrate(unsigned rate_kbit) {
314 video_encoder->change_x264_bitrate(rate_kbit);
318 void configure_card(unsigned card_index, bmusb::CaptureInterface *capture, bool is_fake_capture);
319 void bm_frame(unsigned card_index, uint16_t timecode,
320 bmusb::FrameAllocator::Frame video_frame, size_t video_offset, bmusb::VideoFormat video_format,
321 bmusb::FrameAllocator::Frame audio_frame, size_t audio_offset, bmusb::AudioFormat audio_format);
322 void bm_hotplug_add(libusb_device *dev);
323 void bm_hotplug_remove(unsigned card_index);
324 void place_rectangle(movit::Effect *resample_effect, movit::Effect *padding_effect, float x0, float y0, float x1, float y1);
326 void handle_hotplugged_cards();
327 void schedule_audio_resampling_tasks(unsigned dropped_frames, int num_samples_per_frame, int length_per_frame);
328 void render_one_frame(int64_t duration);
329 void send_audio_level_callback();
330 void audio_thread_func();
331 void process_audio_one_frame(int64_t frame_pts_int, int num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
332 void subsample_chroma(GLuint src_tex, GLuint dst_dst);
333 void release_display_frame(DisplayFrame *frame);
334 double pts() { return double(pts_int) / TIMEBASE; }
339 QSurface *mixer_surface, *h264_encoder_surface;
340 std::unique_ptr<movit::ResourcePool> resource_pool;
341 std::unique_ptr<Theme> theme;
342 std::atomic<unsigned> audio_source_channel{0};
343 std::atomic<unsigned> master_clock_channel{0};
344 std::unique_ptr<movit::EffectChain> display_chain;
345 GLuint cbcr_program_num; // Owned by <resource_pool>.
346 GLuint cbcr_vbo; // Holds position and texcoord data.
347 GLuint cbcr_position_attribute_index, cbcr_texcoord_attribute_index;
348 std::unique_ptr<VideoEncoder> video_encoder;
350 // Effects part of <display_chain>. Owned by <display_chain>.
351 movit::FlatInput *display_input;
353 int64_t pts_int = 0; // In TIMEBASE units.
355 std::mutex bmusb_mutex;
356 bool has_bmusb_thread = false;
358 bmusb::CaptureInterface *capture = nullptr;
359 bool is_fake_capture;
360 std::unique_ptr<PBOFrameAllocator> frame_allocator;
362 // Stuff for the OpenGL context (for texture uploading).
363 QSurface *surface = nullptr;
366 RefCountedFrame frame;
367 int64_t length; // In TIMEBASE units.
369 unsigned field; // Which field (0 or 1) of the frame to use. Always 0 for progressive.
370 std::function<void()> upload_func; // Needs to be called to actually upload the texture to OpenGL.
371 unsigned dropped_frames = 0; // Number of dropped frames before this one.
373 std::queue<NewFrame> new_frames;
374 bool should_quit = false;
375 std::condition_variable new_frames_changed; // Set whenever new_frames (or should_quit) is changed.
377 QueueLengthPolicy queue_length_policy; // Refers to the "new_frames" queue.
379 // Accumulated errors in number of 1/TIMEBASE samples. If OUTPUT_FREQUENCY divided by
380 // frame rate is integer, will always stay zero.
381 unsigned fractional_samples = 0;
383 int last_timecode = -1; // Unwrapped.
385 CaptureCard cards[MAX_CARDS]; // protected by <bmusb_mutex>
386 AudioMixer audio_mixer;
387 void get_one_frame_from_each_card(unsigned master_card_index, CaptureCard::NewFrame new_frames[MAX_CARDS], bool has_new_frame[MAX_CARDS], int num_samples[MAX_CARDS]);
389 InputState input_state;
391 // Cards we have been noticed about being hotplugged, but haven't tried adding yet.
392 // Protected by its own mutex.
393 std::mutex hotplug_mutex;
394 std::vector<libusb_device *> hotplugged_cards;
396 class OutputChannel {
399 void output_frame(DisplayFrame frame);
400 bool get_display_frame(DisplayFrame *frame);
401 void set_frame_ready_callback(new_frame_ready_callback_t callback);
402 void set_transition_names_updated_callback(transition_names_updated_callback_t callback);
403 void set_name_updated_callback(name_updated_callback_t callback);
404 void set_color_updated_callback(color_updated_callback_t callback);
410 Mixer *parent = nullptr; // Not owned.
411 std::mutex frame_mutex;
412 DisplayFrame current_frame, ready_frame; // protected by <frame_mutex>
413 bool has_current_frame = false, has_ready_frame = false; // protected by <frame_mutex>
414 new_frame_ready_callback_t new_frame_ready_callback;
415 transition_names_updated_callback_t transition_names_updated_callback;
416 name_updated_callback_t name_updated_callback;
417 color_updated_callback_t color_updated_callback;
419 std::vector<std::string> last_transition_names;
420 std::string last_name, last_color;
422 OutputChannel output_channel[NUM_OUTPUTS];
424 std::thread mixer_thread;
425 std::thread audio_thread;
426 std::atomic<bool> should_quit{false};
427 std::atomic<bool> should_cut{false};
429 audio_level_callback_t audio_level_callback = nullptr;
430 mutable std::mutex audio_measure_mutex;
431 Ebu_r128_proc r128; // Under audio_measure_mutex.
432 CorrelationMeasurer correlation; // Under audio_measure_mutex.
433 Resampler peak_resampler; // Under audio_measure_mutex.
434 std::atomic<float> peak{0.0f};
436 std::unique_ptr<ALSAOutput> alsa;
443 std::mutex audio_mutex;
444 std::condition_variable audio_task_queue_changed;
445 std::queue<AudioTask> audio_task_queue; // Under audio_mutex.
447 // For mode scanning.
448 bool is_mode_scanning[MAX_CARDS]{ false };
449 std::vector<uint32_t> mode_scanlist[MAX_CARDS];
450 unsigned mode_scanlist_index[MAX_CARDS]{ 0 };
451 std::chrono::steady_clock::time_point last_mode_scan_change[MAX_CARDS];
454 extern Mixer *global_mixer;
455 extern bool uses_mlock;
457 #endif // !defined(_MIXER_H)