4 // The actual video mixer, running in its own separate background thread.
11 #include <movit/effect_chain.h>
12 #include <movit/flat_input.h>
13 #include <zita-resampler/resampler.h>
15 #include <condition_variable>
24 #include "bmusb/bmusb.h"
25 #include "alsa_output.h"
26 #include "ebu_r128_proc.h"
27 #include "h264encode.h"
29 #include "pbo_frame_allocator.h"
30 #include "ref_counted_frame.h"
31 #include "ref_counted_gl_sync.h"
32 #include "resampling_queue.h"
35 #include "stereocompressor.h"
37 #include "input_state.h"
38 #include "correlation_measurer.h"
55 // For any card that's not the master (where we pick out the frames as they
56 // come, as fast as we can process), there's going to be a queue. The question
57 // is when we should drop frames from that queue (apart from the obvious
58 // dropping if the 16-frame queue should become full), especially given that
59 // the frame rate could be lower or higher than the master (either subtly or
60 // dramatically). We have two (conflicting) demands:
62 // 1. We want to avoid starving the queue.
63 // 2. We don't want to add more delay than is needed.
65 // Our general strategy is to drop as many frames as we can (helping for #2)
66 // that we think is safe for #1 given jitter. To this end, we set a lower floor N,
67 // where we assume that if we have N frames in the queue, we're always safe from
68 // starvation. (Typically, N will be 0 or 1. It starts off at 0.) If we have
69 // more than N frames in the queue after reading out the one we need, we head-drop
70 // them to reduce the queue.
72 // N is reduced as follows: If the queue has had at least one spare frame for
73 // at least 50 (master) frames (ie., it's been too conservative for a second),
74 // we reduce N by 1 and reset the timers.
76 // Whenever the queue is starved (we needed a frame but there was none), N was
77 // obviously too low, so we increment N. We will never set N above 5, though.
78 class QueueLengthPolicy {
80 QueueLengthPolicy() {}
81 void reset(unsigned card_index) {
82 this->card_index = card_index;
83 safe_queue_length = 0;
84 frames_with_at_least_one = 0;
87 void update_policy(int queue_length); // Give in -1 for starvation.
88 unsigned get_safe_queue_length() const { return safe_queue_length; }
91 unsigned card_index; // For debugging only.
92 unsigned safe_queue_length = 0; // Called N in the comments.
93 unsigned frames_with_at_least_one = 0;
98 // The surface format is used for offscreen destinations for OpenGL contexts we need.
99 Mixer(const QSurfaceFormat &format, unsigned num_cards);
104 void transition_clicked(int transition_num);
105 void channel_clicked(int preview_num);
110 OUTPUT_INPUT0, // 1, 2, 3, up to 15 follow numerically.
114 struct DisplayFrame {
115 // The chain for rendering this frame. To render a display frame,
116 // first wait for <ready_fence>, then call <setup_chain>
117 // to wire up all the inputs, and then finally call
118 // chain->render_to_screen() or similar.
119 movit::EffectChain *chain;
120 std::function<void()> setup_chain;
122 // Asserted when all the inputs are ready; you cannot render the chain
124 RefCountedGLsync ready_fence;
126 // Holds on to all the input frames needed for this display frame,
127 // so they are not released while still rendering.
128 std::vector<RefCountedFrame> input_frames;
130 // Textures that should be released back to the resource pool
131 // when this frame disappears, if any.
132 // TODO: Refcount these as well?
133 std::vector<GLuint> temp_textures;
135 // Implicitly frees the previous one if there's a new frame available.
136 bool get_display_frame(Output output, DisplayFrame *frame) {
137 return output_channel[output].get_display_frame(frame);
140 typedef std::function<void()> new_frame_ready_callback_t;
141 void set_frame_ready_callback(Output output, new_frame_ready_callback_t callback)
143 output_channel[output].set_frame_ready_callback(callback);
146 typedef std::function<void(float level_lufs, float peak_db,
147 float global_level_lufs, float range_low_lufs, float range_high_lufs,
148 float gain_staging_db, float final_makeup_gain_db,
149 float correlation)> audio_level_callback_t;
150 void set_audio_level_callback(audio_level_callback_t callback)
152 audio_level_callback = callback;
155 std::vector<std::string> get_transition_names()
157 return theme->get_transition_names(pts());
160 unsigned get_num_channels() const
162 return theme->get_num_channels();
165 std::string get_channel_name(unsigned channel) const
167 return theme->get_channel_name(channel);
170 int get_channel_signal(unsigned channel) const
172 return theme->get_channel_signal(channel);
175 int map_signal(unsigned channel)
177 return theme->map_signal(channel);
180 unsigned get_audio_source() const
182 return audio_source_channel;
185 void set_audio_source(unsigned channel)
187 audio_source_channel = channel;
190 void set_signal_mapping(int signal, int card)
192 return theme->set_signal_mapping(signal, card);
195 bool get_supports_set_wb(unsigned channel) const
197 return theme->get_supports_set_wb(channel);
200 void set_wb(unsigned channel, double r, double g, double b) const
202 theme->set_wb(channel, r, g, b);
205 void set_locut_cutoff(float cutoff_hz)
207 locut_cutoff_hz = cutoff_hz;
210 void set_locut_enabled(bool enabled)
212 locut_enabled = enabled;
215 float get_limiter_threshold_dbfs()
217 return limiter_threshold_dbfs;
220 float get_compressor_threshold_dbfs()
222 return compressor_threshold_dbfs;
225 void set_limiter_threshold_dbfs(float threshold_dbfs)
227 limiter_threshold_dbfs = threshold_dbfs;
230 void set_compressor_threshold_dbfs(float threshold_dbfs)
232 compressor_threshold_dbfs = threshold_dbfs;
235 void set_limiter_enabled(bool enabled)
237 limiter_enabled = enabled;
240 void set_compressor_enabled(bool enabled)
242 compressor_enabled = enabled;
245 void set_gain_staging_db(float gain_db)
247 std::unique_lock<std::mutex> lock(compressor_mutex);
248 level_compressor_enabled = false;
249 gain_staging_db = gain_db;
252 void set_gain_staging_auto(bool enabled)
254 std::unique_lock<std::mutex> lock(compressor_mutex);
255 level_compressor_enabled = enabled;
258 void set_final_makeup_gain_db(float gain_db)
260 std::unique_lock<std::mutex> lock(compressor_mutex);
261 final_makeup_gain_auto = false;
262 final_makeup_gain = pow(10.0f, gain_db / 20.0f);
265 void set_final_makeup_gain_auto(bool enabled)
267 std::unique_lock<std::mutex> lock(compressor_mutex);
268 final_makeup_gain_auto = enabled;
278 unsigned get_num_cards() const { return num_cards; }
280 std::string get_card_description(unsigned card_index) const {
281 assert(card_index < num_cards);
282 return cards[card_index].capture->get_description();
285 std::map<uint32_t, VideoMode> get_available_video_modes(unsigned card_index) const {
286 assert(card_index < num_cards);
287 return cards[card_index].capture->get_available_video_modes();
290 uint32_t get_current_video_mode(unsigned card_index) const {
291 assert(card_index < num_cards);
292 return cards[card_index].capture->get_current_video_mode();
295 void set_video_mode(unsigned card_index, uint32_t mode) {
296 assert(card_index < num_cards);
297 cards[card_index].capture->set_video_mode(mode);
300 void start_mode_scanning(unsigned card_index);
302 std::map<uint32_t, std::string> get_available_video_inputs(unsigned card_index) const {
303 assert(card_index < num_cards);
304 return cards[card_index].capture->get_available_video_inputs();
307 uint32_t get_current_video_input(unsigned card_index) const {
308 assert(card_index < num_cards);
309 return cards[card_index].capture->get_current_video_input();
312 void set_video_input(unsigned card_index, uint32_t input) {
313 assert(card_index < num_cards);
314 cards[card_index].capture->set_video_input(input);
317 std::map<uint32_t, std::string> get_available_audio_inputs(unsigned card_index) const {
318 assert(card_index < num_cards);
319 return cards[card_index].capture->get_available_audio_inputs();
322 uint32_t get_current_audio_input(unsigned card_index) const {
323 assert(card_index < num_cards);
324 return cards[card_index].capture->get_current_audio_input();
327 void set_audio_input(unsigned card_index, uint32_t input) {
328 assert(card_index < num_cards);
329 cards[card_index].capture->set_audio_input(input);
333 void configure_card(unsigned card_index, const QSurfaceFormat &format, CaptureInterface *capture);
334 void bm_frame(unsigned card_index, uint16_t timecode,
335 FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
336 FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format);
337 void place_rectangle(movit::Effect *resample_effect, movit::Effect *padding_effect, float x0, float y0, float x1, float y1);
339 void audio_thread_func();
340 void process_audio_one_frame(int64_t frame_pts_int, int num_samples);
341 void subsample_chroma(GLuint src_tex, GLuint dst_dst);
342 void release_display_frame(DisplayFrame *frame);
343 double pts() { return double(pts_int) / TIMEBASE; }
348 QSurface *mixer_surface, *h264_encoder_surface;
349 std::unique_ptr<movit::ResourcePool> resource_pool;
350 std::unique_ptr<Theme> theme;
351 std::atomic<unsigned> audio_source_channel{0};
352 std::unique_ptr<movit::EffectChain> display_chain;
353 GLuint cbcr_program_num; // Owned by <resource_pool>.
354 GLuint cbcr_vbo; // Holds position and texcoord data.
355 GLuint cbcr_position_attribute_index, cbcr_texcoord_attribute_index;
356 std::unique_ptr<H264Encoder> h264_encoder;
358 // Effects part of <display_chain>. Owned by <display_chain>.
359 movit::FlatInput *display_input;
361 int64_t pts_int = 0; // In TIMEBASE units.
363 std::mutex bmusb_mutex;
365 CaptureInterface *capture;
366 std::unique_ptr<PBOFrameAllocator> frame_allocator;
368 // Stuff for the OpenGL context (for texture uploading).
370 QOpenGLContext *context;
373 RefCountedFrame frame;
374 int64_t length; // In TIMEBASE units.
376 unsigned field; // Which field (0 or 1) of the frame to use. Always 0 for progressive.
377 GLsync ready_fence; // Whether frame is ready for rendering.
378 unsigned dropped_frames = 0; // Number of dropped frames before this one.
380 std::queue<NewFrame> new_frames;
381 bool should_quit = false;
382 std::condition_variable new_frames_changed; // Set whenever new_frames (or should_quit) is changed.
384 QueueLengthPolicy queue_length_policy; // Refers to the "new_frames" queue.
386 // Accumulated errors in number of 1/TIMEBASE samples. If OUTPUT_FREQUENCY divided by
387 // frame rate is integer, will always stay zero.
388 unsigned fractional_samples = 0;
390 std::mutex audio_mutex;
391 std::unique_ptr<ResamplingQueue> resampling_queue; // Under audio_mutex.
392 int last_timecode = -1; // Unwrapped.
393 int64_t next_local_pts = 0; // Beginning of next frame, in TIMEBASE units.
395 CaptureCard cards[MAX_CARDS]; // protected by <bmusb_mutex>
397 InputState input_state;
399 class OutputChannel {
402 void output_frame(DisplayFrame frame);
403 bool get_display_frame(DisplayFrame *frame);
404 void set_frame_ready_callback(new_frame_ready_callback_t callback);
409 Mixer *parent = nullptr; // Not owned.
410 std::mutex frame_mutex;
411 DisplayFrame current_frame, ready_frame; // protected by <frame_mutex>
412 bool has_current_frame = false, has_ready_frame = false; // protected by <frame_mutex>
413 new_frame_ready_callback_t new_frame_ready_callback;
414 bool has_new_frame_ready_callback = false;
416 OutputChannel output_channel[NUM_OUTPUTS];
418 std::thread mixer_thread;
419 std::thread audio_thread;
420 std::atomic<bool> should_quit{false};
421 std::atomic<bool> should_cut{false};
423 audio_level_callback_t audio_level_callback = nullptr;
424 std::mutex compressor_mutex;
425 Ebu_r128_proc r128; // Under compressor_mutex.
426 CorrelationMeasurer correlation; // Under compressor_mutex.
428 Resampler peak_resampler;
429 std::atomic<float> peak{0.0f};
431 StereoFilter locut; // Default cutoff 120 Hz, 24 dB/oct.
432 std::atomic<float> locut_cutoff_hz;
433 std::atomic<bool> locut_enabled{true};
435 // First compressor; takes us up to about -12 dBFS.
436 StereoCompressor level_compressor; // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
437 float gain_staging_db = 0.0f; // Under compressor_mutex.
438 bool level_compressor_enabled = true; // Under compressor_mutex.
440 static constexpr float ref_level_dbfs = -14.0f; // Chosen so that we end up around 0 LU in practice.
441 static constexpr float ref_level_lufs = -23.0f; // 0 LU, more or less by definition.
443 StereoCompressor limiter;
444 std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f}; // 4 dB.
445 std::atomic<bool> limiter_enabled{true};
446 StereoCompressor compressor;
447 std::atomic<float> compressor_threshold_dbfs{ref_level_dbfs - 12.0f}; // -12 dB.
448 std::atomic<bool> compressor_enabled{true};
450 double final_makeup_gain = 1.0; // Under compressor_mutex. Read/write by the user. Note: Not in dB, we want the numeric precision so that we can change it slowly.
451 bool final_makeup_gain_auto = true; // Under compressor_mutex.
453 std::unique_ptr<ALSAOutput> alsa;
459 std::mutex audio_mutex;
460 std::condition_variable audio_task_queue_changed;
461 std::queue<AudioTask> audio_task_queue; // Under audio_mutex.
463 // For mode scanning.
464 bool is_mode_scanning[MAX_CARDS]{ false };
465 std::vector<uint32_t> mode_scanlist[MAX_CARDS];
466 unsigned mode_scanlist_index[MAX_CARDS]{ 0 };
467 timespec last_mode_scan_change[MAX_CARDS];
470 extern Mixer *global_mixer;
472 #endif // !defined(_MIXER_H)