1 #include "audio_mixer.h"
4 #include <bmusb/bmusb.h>
23 #include "shared/metrics.h"
25 #include "shared/timebase.h"
27 using namespace bmusb;
29 using namespace std::chrono;
30 using namespace std::placeholders;
34 // TODO: If these prove to be a bottleneck, they can be SSSE3-optimized
35 // (usually including multiple channels at a time).
37 void convert_fixed16_to_fp32(float *dst, size_t out_channel, size_t out_num_channels,
38 const uint8_t *src, size_t in_channel, size_t in_num_channels,
41 assert(in_channel < in_num_channels);
42 assert(out_channel < out_num_channels);
43 src += in_channel * 2;
46 for (size_t i = 0; i < num_samples; ++i) {
47 int16_t s = le16toh(*(int16_t *)src);
48 *dst = s * (1.0f / 32768.0f);
50 src += 2 * in_num_channels;
51 dst += out_num_channels;
55 void convert_fixed16_to_fixed32(int32_t *dst, size_t out_channel, size_t out_num_channels,
56 const uint8_t *src, size_t in_channel, size_t in_num_channels,
59 assert(in_channel < in_num_channels);
60 assert(out_channel < out_num_channels);
61 src += in_channel * 2;
64 for (size_t i = 0; i < num_samples; ++i) {
65 uint32_t s = uint32_t(uint16_t(le16toh(*(int16_t *)src))) << 16;
67 // Keep the sign bit in place, repeat the other 15 bits as far as they go.
68 *dst = s | ((s & 0x7fffffff) >> 15) | ((s & 0x7fffffff) >> 30);
70 src += 2 * in_num_channels;
71 dst += out_num_channels;
75 void convert_fixed24_to_fp32(float *dst, size_t out_channel, size_t out_num_channels,
76 const uint8_t *src, size_t in_channel, size_t in_num_channels,
79 assert(in_channel < in_num_channels);
80 assert(out_channel < out_num_channels);
81 src += in_channel * 3;
84 for (size_t i = 0; i < num_samples; ++i) {
88 uint32_t s = (s1 << 8) | (s2 << 16) | (s3 << 24); // Note: The bottom eight bits are zero; s3 includes the sign bit.
89 *dst = int(s) * (1.0f / (256.0f * 8388608.0f)); // 256 for signed down-shift by 8, then 2^23 for the actual conversion.
91 src += 3 * in_num_channels;
92 dst += out_num_channels;
96 void convert_fixed24_to_fixed32(int32_t *dst, size_t out_channel, size_t out_num_channels,
97 const uint8_t *src, size_t in_channel, size_t in_num_channels,
100 assert(in_channel < in_num_channels);
101 assert(out_channel < out_num_channels);
102 src += in_channel * 3;
105 for (size_t i = 0; i < num_samples; ++i) {
106 uint32_t s1 = src[0];
107 uint32_t s2 = src[1];
108 uint32_t s3 = src[2];
109 uint32_t s = (s1 << 8) | (s2 << 16) | (s3 << 24);
111 // Keep the sign bit in place, repeat the other 23 bits as far as they go.
112 *dst = s | ((s & 0x7fffffff) >> 23);
114 src += 3 * in_num_channels;
115 dst += out_num_channels;
119 void convert_fixed32_to_fp32(float *dst, size_t out_channel, size_t out_num_channels,
120 const uint8_t *src, size_t in_channel, size_t in_num_channels,
123 assert(in_channel < in_num_channels);
124 assert(out_channel < out_num_channels);
125 src += in_channel * 4;
128 for (size_t i = 0; i < num_samples; ++i) {
129 int32_t s = le32toh(*(int32_t *)src);
130 *dst = s * (1.0f / 2147483648.0f);
132 src += 4 * in_num_channels;
133 dst += out_num_channels;
137 // Basically just a reinterleave.
138 void convert_fixed32_to_fixed32(int32_t *dst, size_t out_channel, size_t out_num_channels,
139 const uint8_t *src, size_t in_channel, size_t in_num_channels,
142 assert(in_channel < in_num_channels);
143 assert(out_channel < out_num_channels);
144 src += in_channel * 4;
147 for (size_t i = 0; i < num_samples; ++i) {
148 int32_t s = le32toh(*(int32_t *)src);
151 src += 4 * in_num_channels;
152 dst += out_num_channels;
156 float find_peak_plain(const float *samples, size_t num_samples) __attribute__((unused));
158 float find_peak_plain(const float *samples, size_t num_samples)
160 float m = fabs(samples[0]);
161 for (size_t i = 1; i < num_samples; ++i) {
162 m = max(m, fabs(samples[i]));
168 static inline float horizontal_max(__m128 m)
170 __m128 tmp = _mm_shuffle_ps(m, m, _MM_SHUFFLE(1, 0, 3, 2));
171 m = _mm_max_ps(m, tmp);
172 tmp = _mm_shuffle_ps(m, m, _MM_SHUFFLE(2, 3, 0, 1));
173 m = _mm_max_ps(m, tmp);
174 return _mm_cvtss_f32(m);
177 float find_peak(const float *samples, size_t num_samples)
179 const __m128 abs_mask = _mm_castsi128_ps(_mm_set1_epi32(0x7fffffffu));
180 __m128 m = _mm_setzero_ps();
181 for (size_t i = 0; i < (num_samples & ~3); i += 4) {
182 __m128 x = _mm_loadu_ps(samples + i);
183 x = _mm_and_ps(x, abs_mask);
184 m = _mm_max_ps(m, x);
186 float result = horizontal_max(m);
188 for (size_t i = (num_samples & ~3); i < num_samples; ++i) {
189 result = max(result, fabs(samples[i]));
193 // Self-test. We should be bit-exact the same.
194 float reference_result = find_peak_plain(samples, num_samples);
195 if (result != reference_result) {
196 fprintf(stderr, "Error: Peak is %f [%f %f %f %f]; should be %f.\n",
198 _mm_cvtss_f32(_mm_shuffle_ps(m, m, _MM_SHUFFLE(0, 0, 0, 0))),
199 _mm_cvtss_f32(_mm_shuffle_ps(m, m, _MM_SHUFFLE(1, 1, 1, 1))),
200 _mm_cvtss_f32(_mm_shuffle_ps(m, m, _MM_SHUFFLE(2, 2, 2, 2))),
201 _mm_cvtss_f32(_mm_shuffle_ps(m, m, _MM_SHUFFLE(3, 3, 3, 3))),
209 float find_peak(const float *samples, size_t num_samples)
211 return find_peak_plain(samples, num_samples);
215 void deinterleave_samples(const vector<float> &in, vector<float> *out_l, vector<float> *out_r)
217 size_t num_samples = in.size() / 2;
218 out_l->resize(num_samples);
219 out_r->resize(num_samples);
221 const float *inptr = in.data();
222 float *lptr = &(*out_l)[0];
223 float *rptr = &(*out_r)[0];
224 for (size_t i = 0; i < num_samples; ++i) {
232 AudioMixer::AudioMixer(unsigned num_capture_cards, unsigned num_ffmpeg_inputs)
233 : num_capture_cards(num_capture_cards),
234 num_ffmpeg_inputs(num_ffmpeg_inputs),
235 ffmpeg_inputs(new AudioDevice[num_ffmpeg_inputs]),
236 limiter(OUTPUT_FREQUENCY),
237 correlation(OUTPUT_FREQUENCY)
239 for (unsigned bus_index = 0; bus_index < MAX_BUSES; ++bus_index) {
240 locut[bus_index].init(FILTER_HPF, 2);
241 eq[bus_index][EQ_BAND_BASS].init(FILTER_LOW_SHELF, 1);
242 // Note: EQ_BAND_MID isn't used (see comments in apply_eq()).
243 eq[bus_index][EQ_BAND_TREBLE].init(FILTER_HIGH_SHELF, 1);
244 compressor[bus_index].reset(new StereoCompressor(OUTPUT_FREQUENCY));
245 level_compressor[bus_index].reset(new StereoCompressor(OUTPUT_FREQUENCY));
247 set_bus_settings(bus_index, get_default_bus_settings());
249 set_limiter_enabled(global_flags.limiter_enabled);
250 set_final_makeup_gain_auto(global_flags.final_makeup_gain_auto);
252 r128.init(2, OUTPUT_FREQUENCY);
255 // hlen=16 is pretty low quality, but we use quite a bit of CPU otherwise,
256 // and there's a limit to how important the peak meter is.
257 peak_resampler.setup(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY * 4, /*num_channels=*/2, /*hlen=*/16, /*frel=*/1.0);
259 global_audio_mixer = this;
262 if (!global_flags.input_mapping_filename.empty()) {
263 // Must happen after ALSAPool is initialized, as it needs to know the card list.
264 current_mapping_mode = MappingMode::MULTICHANNEL;
265 InputMapping new_input_mapping;
266 if (!load_input_mapping_from_file(get_devices(),
267 global_flags.input_mapping_filename,
268 &new_input_mapping)) {
269 fprintf(stderr, "Failed to load input mapping from '%s', exiting.\n",
270 global_flags.input_mapping_filename.c_str());
273 set_input_mapping(new_input_mapping);
275 set_simple_input(/*card_index=*/0);
276 if (global_flags.multichannel_mapping_mode) {
277 current_mapping_mode = MappingMode::MULTICHANNEL;
281 global_metrics.add("audio_loudness_short_lufs", &metric_audio_loudness_short_lufs, Metrics::TYPE_GAUGE);
282 global_metrics.add("audio_loudness_integrated_lufs", &metric_audio_loudness_integrated_lufs, Metrics::TYPE_GAUGE);
283 global_metrics.add("audio_loudness_range_low_lufs", &metric_audio_loudness_range_low_lufs, Metrics::TYPE_GAUGE);
284 global_metrics.add("audio_loudness_range_high_lufs", &metric_audio_loudness_range_high_lufs, Metrics::TYPE_GAUGE);
285 global_metrics.add("audio_peak_dbfs", &metric_audio_peak_dbfs, Metrics::TYPE_GAUGE);
286 global_metrics.add("audio_final_makeup_gain_db", &metric_audio_final_makeup_gain_db, Metrics::TYPE_GAUGE);
287 global_metrics.add("audio_correlation", &metric_audio_correlation, Metrics::TYPE_GAUGE);
290 void AudioMixer::reset_resampler(DeviceSpec device_spec)
292 lock_guard<timed_mutex> lock(audio_mutex);
293 reset_resampler_mutex_held(device_spec);
296 void AudioMixer::reset_resampler_mutex_held(DeviceSpec device_spec)
298 AudioDevice *device = find_audio_device(device_spec);
300 if (device->interesting_channels.empty()) {
301 device->resampling_queue.reset();
303 device->resampling_queue.reset(new ResamplingQueue(
304 device_spec, device->capture_frequency, OUTPUT_FREQUENCY, device->interesting_channels.size(),
305 global_flags.audio_queue_length_ms * 0.001));
309 bool AudioMixer::add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, AudioFormat audio_format, steady_clock::time_point frame_time)
311 AudioDevice *device = find_audio_device(device_spec);
313 unique_lock<timed_mutex> lock(audio_mutex, defer_lock);
314 if (!lock.try_lock_for(chrono::milliseconds(10))) {
317 if (device->resampling_queue == nullptr) {
318 // No buses use this device; throw it away.
322 unsigned num_channels = device->interesting_channels.size();
323 assert(num_channels > 0);
325 // Convert the audio to fp32.
326 unique_ptr<float[]> audio(new float[num_samples * num_channels]);
327 unsigned channel_index = 0;
328 for (auto channel_it = device->interesting_channels.cbegin(); channel_it != device->interesting_channels.end(); ++channel_it, ++channel_index) {
329 switch (audio_format.bits_per_sample) {
331 assert(num_samples == 0);
334 convert_fixed16_to_fp32(audio.get(), channel_index, num_channels, data, *channel_it, audio_format.num_channels, num_samples);
337 convert_fixed24_to_fp32(audio.get(), channel_index, num_channels, data, *channel_it, audio_format.num_channels, num_samples);
340 convert_fixed32_to_fp32(audio.get(), channel_index, num_channels, data, *channel_it, audio_format.num_channels, num_samples);
343 fprintf(stderr, "Cannot handle audio with %u bits per sample\n", audio_format.bits_per_sample);
348 // If we changed frequency since last frame, we'll need to reset the resampler.
349 if (audio_format.sample_rate != device->capture_frequency) {
350 device->capture_frequency = audio_format.sample_rate;
351 reset_resampler_mutex_held(device_spec);
355 device->resampling_queue->add_input_samples(frame_time, audio.get(), num_samples, ResamplingQueue::ADJUST_RATE);
359 vector<int32_t> convert_audio_to_fixed32(const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, unsigned num_channels)
361 vector<int32_t> audio;
363 if (num_channels > audio_format.num_channels) {
364 audio.resize(num_samples * num_channels, 0);
366 audio.resize(num_samples * num_channels);
368 for (unsigned channel_index = 0; channel_index < num_channels && channel_index < audio_format.num_channels; ++channel_index) {
369 switch (audio_format.bits_per_sample) {
371 assert(num_samples == 0);
374 convert_fixed16_to_fixed32(&audio[0], channel_index, num_channels, data, channel_index, audio_format.num_channels, num_samples);
377 convert_fixed24_to_fixed32(&audio[0], channel_index, num_channels, data, channel_index, audio_format.num_channels, num_samples);
380 convert_fixed32_to_fixed32(&audio[0], channel_index, num_channels, data, channel_index, audio_format.num_channels, num_samples);
383 fprintf(stderr, "Cannot handle audio with %u bits per sample\n", audio_format.bits_per_sample);
391 bool AudioMixer::add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames)
393 AudioDevice *device = find_audio_device(device_spec);
395 unique_lock<timed_mutex> lock(audio_mutex, defer_lock);
396 if (!lock.try_lock_for(chrono::milliseconds(10))) {
399 if (device->resampling_queue == nullptr) {
400 // No buses use this device; throw it away.
404 unsigned num_channels = device->interesting_channels.size();
405 assert(num_channels > 0);
407 vector<float> silence(samples_per_frame * num_channels, 0.0f);
408 for (unsigned i = 0; i < num_frames; ++i) {
409 device->resampling_queue->add_input_samples(steady_clock::now(), silence.data(), samples_per_frame, ResamplingQueue::DO_NOT_ADJUST_RATE);
414 bool AudioMixer::silence_card(DeviceSpec device_spec, bool silence)
416 AudioDevice *device = find_audio_device(device_spec);
418 unique_lock<timed_mutex> lock(audio_mutex, defer_lock);
419 if (!lock.try_lock_for(chrono::milliseconds(10))) {
423 if (device->silenced && !silence) {
424 reset_resampler_mutex_held(device_spec);
426 device->silenced = silence;
430 AudioMixer::BusSettings AudioMixer::get_default_bus_settings()
432 BusSettings settings;
433 settings.fader_volume_db = 0.0f;
434 settings.muted = false;
435 settings.locut_enabled = global_flags.locut_enabled;
436 settings.stereo_width = 1.0f;
437 for (unsigned band_index = 0; band_index < NUM_EQ_BANDS; ++band_index) {
438 settings.eq_level_db[band_index] = 0.0f;
440 settings.gain_staging_db = global_flags.initial_gain_staging_db;
441 settings.level_compressor_enabled = global_flags.gain_staging_auto;
442 settings.compressor_threshold_dbfs = ref_level_dbfs - 12.0f; // -12 dB.
443 settings.compressor_enabled = global_flags.compressor_enabled;
447 AudioMixer::BusSettings AudioMixer::get_bus_settings(unsigned bus_index) const
449 lock_guard<timed_mutex> lock(audio_mutex);
450 BusSettings settings;
451 settings.fader_volume_db = fader_volume_db[bus_index];
452 settings.muted = mute[bus_index];
453 settings.locut_enabled = locut_enabled[bus_index];
454 settings.stereo_width = stereo_width[bus_index];
455 for (unsigned band_index = 0; band_index < NUM_EQ_BANDS; ++band_index) {
456 settings.eq_level_db[band_index] = eq_level_db[bus_index][band_index];
458 settings.gain_staging_db = gain_staging_db[bus_index];
459 settings.level_compressor_enabled = level_compressor_enabled[bus_index];
460 settings.compressor_threshold_dbfs = compressor_threshold_dbfs[bus_index];
461 settings.compressor_enabled = compressor_enabled[bus_index];
465 void AudioMixer::set_bus_settings(unsigned bus_index, const AudioMixer::BusSettings &settings)
467 lock_guard<timed_mutex> lock(audio_mutex);
468 fader_volume_db[bus_index] = settings.fader_volume_db;
469 mute[bus_index] = settings.muted;
470 locut_enabled[bus_index] = settings.locut_enabled;
471 stereo_width[bus_index] = settings.stereo_width;
472 for (unsigned band_index = 0; band_index < NUM_EQ_BANDS; ++band_index) {
473 eq_level_db[bus_index][band_index] = settings.eq_level_db[band_index];
475 gain_staging_db[bus_index] = settings.gain_staging_db;
476 last_gain_staging_db[bus_index] = gain_staging_db[bus_index];
477 level_compressor_enabled[bus_index] = settings.level_compressor_enabled;
478 compressor_threshold_dbfs[bus_index] = settings.compressor_threshold_dbfs;
479 compressor_enabled[bus_index] = settings.compressor_enabled;
482 AudioMixer::AudioDevice *AudioMixer::find_audio_device(DeviceSpec device)
484 switch (device.type) {
485 case InputSourceType::CAPTURE_CARD:
486 return &video_cards[device.index];
487 case InputSourceType::ALSA_INPUT:
488 return &alsa_inputs[device.index];
489 case InputSourceType::FFMPEG_VIDEO_INPUT:
490 return &ffmpeg_inputs[device.index];
491 case InputSourceType::SILENCE:
498 // Get a pointer to the given channel from the given device.
499 // The channel must be picked out earlier and resampled.
500 void AudioMixer::find_sample_src_from_device(const map<DeviceSpec, vector<float>> &samples_card, DeviceSpec device_spec, int source_channel, const float **srcptr, unsigned *stride)
502 static float zero = 0.0f;
503 if (source_channel == -1 || device_spec.type == InputSourceType::SILENCE) {
508 AudioDevice *device = find_audio_device(device_spec);
509 assert(device->interesting_channels.count(source_channel) != 0);
510 unsigned channel_index = 0;
511 for (int channel : device->interesting_channels) {
512 if (channel == source_channel) break;
515 assert(channel_index < device->interesting_channels.size());
516 const auto it = samples_card.find(device_spec);
517 assert(it != samples_card.end());
518 *srcptr = &(it->second)[channel_index];
519 *stride = device->interesting_channels.size();
522 // TODO: Can be SSSE3-optimized if need be.
523 void AudioMixer::fill_audio_bus(const map<DeviceSpec, vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float stereo_width, float *output)
525 if (bus.device.type == InputSourceType::SILENCE) {
526 memset(output, 0, num_samples * 2 * sizeof(*output));
528 assert(bus.device.type == InputSourceType::CAPTURE_CARD ||
529 bus.device.type == InputSourceType::ALSA_INPUT ||
530 bus.device.type == InputSourceType::FFMPEG_VIDEO_INPUT);
531 const float *lsrc, *rsrc;
532 unsigned lstride, rstride;
533 float *dptr = output;
534 find_sample_src_from_device(samples_card, bus.device, bus.source_channel[0], &lsrc, &lstride);
535 find_sample_src_from_device(samples_card, bus.device, bus.source_channel[1], &rsrc, &rstride);
537 // Apply stereo width settings. Set stereo width w to a 0..1 range instead of
538 // -1..1, since it makes for much easier calculations (so 0.5 = completely mono).
539 // Then, what we want is
541 // L' = wL + (1-w)R = R + w(L-R)
542 // R' = wR + (1-w)L = L + w(R-L)
544 // This can be further simplified calculation-wise by defining the weighted
545 // difference signal D = w(R-L), so that:
549 float w = 0.5f * stereo_width + 0.5f;
550 if (bus.source_channel[0] == bus.source_channel[1]) {
551 // Mono anyway, so no need to bother.
553 } else if (fabs(w) < 1e-3) {
556 swap(lstride, rstride);
559 if (fabs(w - 1.0f) < 1e-3) {
560 // No calculations needed for stereo_width = 1.
561 for (unsigned i = 0; i < num_samples; ++i) {
569 for (unsigned i = 0; i < num_samples; ++i) {
570 float left = *lsrc, right = *rsrc;
571 float diff = w * (right - left);
572 *dptr++ = right - diff;
573 *dptr++ = left + diff;
581 vector<DeviceSpec> AudioMixer::get_active_devices() const
583 vector<DeviceSpec> ret;
584 for (unsigned card_index = 0; card_index < MAX_VIDEO_CARDS; ++card_index) {
585 const DeviceSpec device_spec{InputSourceType::CAPTURE_CARD, card_index};
586 if (!find_audio_device(device_spec)->interesting_channels.empty()) {
587 ret.push_back(device_spec);
590 for (unsigned card_index = 0; card_index < MAX_ALSA_CARDS; ++card_index) {
591 const DeviceSpec device_spec{InputSourceType::ALSA_INPUT, card_index};
592 if (!find_audio_device(device_spec)->interesting_channels.empty()) {
593 ret.push_back(device_spec);
596 for (unsigned card_index = 0; card_index < num_ffmpeg_inputs; ++card_index) {
597 const DeviceSpec device_spec{InputSourceType::FFMPEG_VIDEO_INPUT, card_index};
598 if (!find_audio_device(device_spec)->interesting_channels.empty()) {
599 ret.push_back(device_spec);
607 void apply_gain(float db, float last_db, vector<float> *samples)
609 if (fabs(db - last_db) < 1e-3) {
610 // Constant over this frame.
611 const float gain = from_db(db);
612 for (size_t i = 0; i < samples->size(); ++i) {
613 (*samples)[i] *= gain;
616 // We need to do a fade.
617 unsigned num_samples = samples->size() / 2;
618 float gain = from_db(last_db);
619 const float gain_inc = pow(from_db(db - last_db), 1.0 / num_samples);
620 for (size_t i = 0; i < num_samples; ++i) {
621 (*samples)[i * 2 + 0] *= gain;
622 (*samples)[i * 2 + 1] *= gain;
630 vector<float> AudioMixer::get_output(steady_clock::time_point ts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy)
632 map<DeviceSpec, vector<float>> samples_card;
633 vector<float> samples_bus;
635 lock_guard<timed_mutex> lock(audio_mutex);
637 // Pick out all the interesting channels from all the cards.
638 for (const DeviceSpec &device_spec : get_active_devices()) {
639 AudioDevice *device = find_audio_device(device_spec);
640 samples_card[device_spec].resize(num_samples * device->interesting_channels.size());
641 if (device->silenced) {
642 memset(&samples_card[device_spec][0], 0, samples_card[device_spec].size() * sizeof(float));
644 device->resampling_queue->get_output_samples(
646 &samples_card[device_spec][0],
648 rate_adjustment_policy);
652 vector<float> samples_out, left, right;
653 samples_out.resize(num_samples * 2);
654 samples_bus.resize(num_samples * 2);
655 for (unsigned bus_index = 0; bus_index < input_mapping.buses.size(); ++bus_index) {
656 fill_audio_bus(samples_card, input_mapping.buses[bus_index], num_samples, stereo_width[bus_index], &samples_bus[0]);
657 apply_eq(bus_index, &samples_bus);
660 lock_guard<mutex> lock(compressor_mutex);
662 // Apply a level compressor to get the general level right.
663 // Basically, if it's over about -40 dBFS, we squeeze it down to that level
664 // (or more precisely, near it, since we don't use infinite ratio),
665 // then apply a makeup gain to get it to -14 dBFS. -14 dBFS is, of course,
666 // entirely arbitrary, but from practical tests with speech, it seems to
667 // put ut around -23 LUFS, so it's a reasonable starting point for later use.
668 if (level_compressor_enabled[bus_index]) {
669 float threshold = 0.01f; // -40 dBFS.
671 float attack_time = 0.5f;
672 float release_time = 20.0f;
673 float makeup_gain = from_db(ref_level_dbfs - (-40.0f)); // +26 dB.
674 level_compressor[bus_index]->process(samples_bus.data(), samples_bus.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
675 gain_staging_db[bus_index] = to_db(level_compressor[bus_index]->get_attenuation() * makeup_gain);
677 // Just apply the gain we already had.
678 float db = gain_staging_db[bus_index];
679 float last_db = last_gain_staging_db[bus_index];
680 apply_gain(db, last_db, &samples_bus);
682 last_gain_staging_db[bus_index] = gain_staging_db[bus_index];
685 printf("level=%f (%+5.2f dBFS) attenuation=%f (%+5.2f dB) end_result=%+5.2f dB\n",
686 level_compressor.get_level(), to_db(level_compressor.get_level()),
687 level_compressor.get_attenuation(), to_db(level_compressor.get_attenuation()),
688 to_db(level_compressor.get_level() * level_compressor.get_attenuation() * makeup_gain));
691 // The real compressor.
692 if (compressor_enabled[bus_index]) {
693 float threshold = from_db(compressor_threshold_dbfs[bus_index]);
695 float attack_time = 0.005f;
696 float release_time = 0.040f;
697 float makeup_gain = 2.0f; // +6 dB.
698 compressor[bus_index]->process(samples_bus.data(), samples_bus.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
699 // compressor_att = compressor.get_attenuation();
703 add_bus_to_master(bus_index, samples_bus, &samples_out);
704 deinterleave_samples(samples_bus, &left, &right);
705 measure_bus_levels(bus_index, left, right);
709 lock_guard<mutex> lock(compressor_mutex);
711 // Finally a limiter at -4 dB (so, -10 dBFS) to take out the worst peaks only.
712 // Note that since ratio is not infinite, we could go slightly higher than this.
713 if (limiter_enabled) {
714 float threshold = from_db(limiter_threshold_dbfs);
716 float attack_time = 0.0f; // Instant.
717 float release_time = 0.020f;
718 float makeup_gain = 1.0f; // 0 dB.
719 limiter.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
720 // limiter_att = limiter.get_attenuation();
723 // printf("limiter=%+5.1f compressor=%+5.1f\n", to_db(limiter_att), to_db(compressor_att));
726 // At this point, we are most likely close to +0 LU (at least if the
727 // faders sum to 0 dB and the compressors are on), but all of our
728 // measurements have been on raw sample values, not R128 values.
729 // So we have a final makeup gain to get us to +0 LU; the gain
730 // adjustments required should be relatively small, and also, the
731 // offset shouldn't change much (only if the type of audio changes
732 // significantly). Thus, we shoot for updating this value basically
733 // “whenever we process buffers”, since the R128 calculation isn't exactly
734 // something we get out per-sample.
736 // Note that there's a feedback loop here, so we choose a very slow filter
737 // (half-time of 30 seconds).
738 double target_loudness_factor, alpha;
739 double loudness_lu = r128.loudness_M() - ref_level_lufs;
740 target_loudness_factor = final_makeup_gain * from_db(-loudness_lu);
742 // If we're outside +/- 5 LU (after correction), we don't count it as
743 // a normal signal (probably silence) and don't change the
744 // correction factor; just apply what we already have.
745 if (fabs(loudness_lu) >= 5.0 || !final_makeup_gain_auto) {
748 // Formula adapted from
749 // https://en.wikipedia.org/wiki/Low-pass_filter#Simple_infinite_impulse_response_filter.
750 const double half_time_s = 30.0;
751 const double fc_mul_2pi_delta_t = 1.0 / (half_time_s * OUTPUT_FREQUENCY);
752 alpha = fc_mul_2pi_delta_t / (fc_mul_2pi_delta_t + 1.0);
756 lock_guard<mutex> lock(compressor_mutex);
757 double m = final_makeup_gain;
758 for (size_t i = 0; i < samples_out.size(); i += 2) {
759 samples_out[i + 0] *= m;
760 samples_out[i + 1] *= m;
761 m += (target_loudness_factor - m) * alpha;
763 final_makeup_gain = m;
766 update_meters(samples_out);
773 void apply_filter_fade(StereoFilter *filter, float *data, unsigned num_samples, float cutoff_hz, float db, float last_db)
775 // A granularity of 32 samples is an okay tradeoff between speed and
776 // smoothness; recalculating the filters is pretty expensive, so it's
777 // good that we don't do this all the time.
778 static constexpr unsigned filter_granularity_samples = 32;
780 const float cutoff_linear = cutoff_hz * 2.0 * M_PI / OUTPUT_FREQUENCY;
781 if (fabs(db - last_db) < 1e-3) {
782 // Constant over this frame.
783 if (fabs(db) > 0.01f) {
784 filter->render(data, num_samples, cutoff_linear, 0.5f, db / 40.0f);
787 // We need to do a fade. (Rounding up avoids division by zero.)
788 unsigned num_blocks = (num_samples + filter_granularity_samples - 1) / filter_granularity_samples;
789 const float inc_db_norm = (db - last_db) / 40.0f / num_blocks;
790 float db_norm = db / 40.0f;
791 for (size_t i = 0; i < num_samples; i += filter_granularity_samples) {
792 size_t samples_this_block = std::min<size_t>(num_samples - i, filter_granularity_samples);
793 filter->render(data + i * 2, samples_this_block, cutoff_linear, 0.5f, db_norm);
794 db_norm += inc_db_norm;
801 void AudioMixer::apply_eq(unsigned bus_index, vector<float> *samples_bus)
803 constexpr float bass_freq_hz = 200.0f;
804 constexpr float treble_freq_hz = 4700.0f;
806 // Cut away everything under 120 Hz (or whatever the cutoff is);
807 // we don't need it for voice, and it will reduce headroom
808 // and confuse the compressor. (In particular, any hums at 50 or 60 Hz
809 // should be dampened.)
810 if (locut_enabled[bus_index]) {
811 locut[bus_index].render(samples_bus->data(), samples_bus->size() / 2, locut_cutoff_hz * 2.0 * M_PI / OUTPUT_FREQUENCY, 0.5f);
814 // Apply the rest of the EQ. Since we only have a simple three-band EQ,
815 // we can implement it with two shelf filters. We use a simple gain to
816 // set the mid-level filter, and then offset the low and high bands
817 // from that if we need to. (We could perhaps have folded the gain into
818 // the next part, but it's so cheap that the trouble isn't worth it.)
820 // If any part of the EQ has changed appreciably since last frame,
821 // we fade smoothly during the course of this frame.
822 const float bass_db = eq_level_db[bus_index][EQ_BAND_BASS];
823 const float mid_db = eq_level_db[bus_index][EQ_BAND_MID];
824 const float treble_db = eq_level_db[bus_index][EQ_BAND_TREBLE];
826 const float last_bass_db = last_eq_level_db[bus_index][EQ_BAND_BASS];
827 const float last_mid_db = last_eq_level_db[bus_index][EQ_BAND_MID];
828 const float last_treble_db = last_eq_level_db[bus_index][EQ_BAND_TREBLE];
830 assert(samples_bus->size() % 2 == 0);
831 const unsigned num_samples = samples_bus->size() / 2;
833 apply_gain(mid_db, last_mid_db, samples_bus);
835 apply_filter_fade(&eq[bus_index][EQ_BAND_BASS], samples_bus->data(), num_samples, bass_freq_hz, bass_db - mid_db, last_bass_db - last_mid_db);
836 apply_filter_fade(&eq[bus_index][EQ_BAND_TREBLE], samples_bus->data(), num_samples, treble_freq_hz, treble_db - mid_db, last_treble_db - last_mid_db);
838 last_eq_level_db[bus_index][EQ_BAND_BASS] = bass_db;
839 last_eq_level_db[bus_index][EQ_BAND_MID] = mid_db;
840 last_eq_level_db[bus_index][EQ_BAND_TREBLE] = treble_db;
843 void AudioMixer::add_bus_to_master(unsigned bus_index, const vector<float> &samples_bus, vector<float> *samples_out)
845 assert(samples_bus.size() == samples_out->size());
846 assert(samples_bus.size() % 2 == 0);
847 unsigned num_samples = samples_bus.size() / 2;
848 const float new_volume_db = mute[bus_index] ? -90.0f : fader_volume_db[bus_index].load();
849 if (fabs(new_volume_db - last_fader_volume_db[bus_index]) > 1e-3) {
850 // The volume has changed; do a fade over the course of this frame.
851 // (We might have some numerical issues here, but it seems to sound OK.)
852 // For the purpose of fading here, the silence floor is set to -90 dB
853 // (the fader only goes to -84).
854 float old_volume = from_db(max<float>(last_fader_volume_db[bus_index], -90.0f));
855 float volume = from_db(max<float>(new_volume_db, -90.0f));
857 float volume_inc = pow(volume / old_volume, 1.0 / num_samples);
859 if (bus_index == 0) {
860 for (unsigned i = 0; i < num_samples; ++i) {
861 (*samples_out)[i * 2 + 0] = samples_bus[i * 2 + 0] * volume;
862 (*samples_out)[i * 2 + 1] = samples_bus[i * 2 + 1] * volume;
863 volume *= volume_inc;
866 for (unsigned i = 0; i < num_samples; ++i) {
867 (*samples_out)[i * 2 + 0] += samples_bus[i * 2 + 0] * volume;
868 (*samples_out)[i * 2 + 1] += samples_bus[i * 2 + 1] * volume;
869 volume *= volume_inc;
872 } else if (new_volume_db > -90.0f) {
873 float volume = from_db(new_volume_db);
874 if (bus_index == 0) {
875 for (unsigned i = 0; i < num_samples; ++i) {
876 (*samples_out)[i * 2 + 0] = samples_bus[i * 2 + 0] * volume;
877 (*samples_out)[i * 2 + 1] = samples_bus[i * 2 + 1] * volume;
880 for (unsigned i = 0; i < num_samples; ++i) {
881 (*samples_out)[i * 2 + 0] += samples_bus[i * 2 + 0] * volume;
882 (*samples_out)[i * 2 + 1] += samples_bus[i * 2 + 1] * volume;
887 last_fader_volume_db[bus_index] = new_volume_db;
890 void AudioMixer::measure_bus_levels(unsigned bus_index, const vector<float> &left, const vector<float> &right)
892 assert(left.size() == right.size());
893 const float volume = mute[bus_index] ? 0.0f : from_db(fader_volume_db[bus_index]);
894 const float peak_levels[2] = {
895 find_peak(left.data(), left.size()) * volume,
896 find_peak(right.data(), right.size()) * volume
898 for (unsigned channel = 0; channel < 2; ++channel) {
899 // Compute the current value, including hold and falloff.
900 // The constants are borrowed from zita-mu1 by Fons Adriaensen.
901 static constexpr float hold_sec = 0.5f;
902 static constexpr float falloff_db_sec = 15.0f; // dB/sec falloff after hold.
904 PeakHistory &history = peak_history[bus_index][channel];
905 history.historic_peak = max(history.historic_peak, peak_levels[channel]);
906 if (history.age_seconds < hold_sec) {
907 current_peak = history.last_peak;
909 current_peak = history.last_peak * from_db(-falloff_db_sec * (history.age_seconds - hold_sec));
912 // See if we have a new peak to replace the old (possibly falling) one.
913 if (peak_levels[channel] > current_peak) {
914 history.last_peak = peak_levels[channel];
915 history.age_seconds = 0.0f; // Not 100% correct, but more than good enough given our frame sizes.
916 current_peak = peak_levels[channel];
918 history.age_seconds += float(left.size()) / OUTPUT_FREQUENCY;
920 history.current_level = peak_levels[channel];
921 history.current_peak = current_peak;
925 void AudioMixer::update_meters(const vector<float> &samples)
927 // Upsample 4x to find interpolated peak.
928 peak_resampler.inp_data = const_cast<float *>(samples.data());
929 peak_resampler.inp_count = samples.size() / 2;
931 vector<float> interpolated_samples;
932 interpolated_samples.resize(samples.size());
934 lock_guard<mutex> lock(audio_measure_mutex);
936 while (peak_resampler.inp_count > 0) { // About four iterations.
937 peak_resampler.out_data = &interpolated_samples[0];
938 peak_resampler.out_count = interpolated_samples.size() / 2;
939 peak_resampler.process();
940 size_t out_stereo_samples = interpolated_samples.size() / 2 - peak_resampler.out_count;
941 peak = max<float>(peak, find_peak(interpolated_samples.data(), out_stereo_samples * 2));
942 peak_resampler.out_data = nullptr;
946 // Find R128 levels and L/R correlation.
947 vector<float> left, right;
948 deinterleave_samples(samples, &left, &right);
949 float *ptrs[] = { left.data(), right.data() };
951 lock_guard<mutex> lock(audio_measure_mutex);
952 r128.process(left.size(), ptrs);
953 correlation.process_samples(samples);
956 send_audio_level_callback();
959 void AudioMixer::reset_meters()
961 lock_guard<mutex> lock(audio_measure_mutex);
962 peak_resampler.reset();
969 void AudioMixer::send_audio_level_callback()
971 if (audio_level_callback == nullptr) {
975 lock_guard<mutex> lock(audio_measure_mutex);
976 double loudness_s = r128.loudness_S();
977 double loudness_i = r128.integrated();
978 double loudness_range_low = r128.range_min();
979 double loudness_range_high = r128.range_max();
981 metric_audio_loudness_short_lufs = loudness_s;
982 metric_audio_loudness_integrated_lufs = loudness_i;
983 metric_audio_loudness_range_low_lufs = loudness_range_low;
984 metric_audio_loudness_range_high_lufs = loudness_range_high;
985 metric_audio_peak_dbfs = to_db(peak);
986 metric_audio_final_makeup_gain_db = to_db(final_makeup_gain);
987 metric_audio_correlation = correlation.get_correlation();
989 vector<BusLevel> bus_levels;
990 bus_levels.resize(input_mapping.buses.size());
992 lock_guard<mutex> lock(compressor_mutex);
993 for (unsigned bus_index = 0; bus_index < bus_levels.size(); ++bus_index) {
994 BusLevel &levels = bus_levels[bus_index];
995 BusMetrics &metrics = bus_metrics[bus_index];
997 levels.current_level_dbfs[0] = metrics.current_level_dbfs[0] = to_db(peak_history[bus_index][0].current_level);
998 levels.current_level_dbfs[1] = metrics.current_level_dbfs[1] = to_db(peak_history[bus_index][1].current_level);
999 levels.peak_level_dbfs[0] = metrics.peak_level_dbfs[0] = to_db(peak_history[bus_index][0].current_peak);
1000 levels.peak_level_dbfs[1] = metrics.peak_level_dbfs[1] = to_db(peak_history[bus_index][1].current_peak);
1001 levels.historic_peak_dbfs = metrics.historic_peak_dbfs = to_db(
1002 max(peak_history[bus_index][0].historic_peak,
1003 peak_history[bus_index][1].historic_peak));
1004 levels.gain_staging_db = metrics.gain_staging_db = gain_staging_db[bus_index];
1005 if (compressor_enabled[bus_index]) {
1006 levels.compressor_attenuation_db = metrics.compressor_attenuation_db = -to_db(compressor[bus_index]->get_attenuation());
1008 levels.compressor_attenuation_db = 0.0;
1009 metrics.compressor_attenuation_db = 0.0 / 0.0;
1014 audio_level_callback(loudness_s, to_db(peak), bus_levels,
1015 loudness_i, loudness_range_low, loudness_range_high,
1016 to_db(final_makeup_gain),
1017 correlation.get_correlation());
1020 map<DeviceSpec, DeviceInfo> AudioMixer::get_devices()
1022 lock_guard<timed_mutex> lock(audio_mutex);
1024 map<DeviceSpec, DeviceInfo> devices;
1025 for (unsigned card_index = 0; card_index < num_capture_cards; ++card_index) {
1026 const DeviceSpec spec{ InputSourceType::CAPTURE_CARD, card_index };
1027 const AudioDevice *device = &video_cards[card_index];
1029 info.display_name = device->display_name;
1030 info.num_channels = 8;
1031 devices.insert(make_pair(spec, info));
1033 vector<ALSAPool::Device> available_alsa_devices = alsa_pool.get_devices();
1034 for (unsigned card_index = 0; card_index < available_alsa_devices.size(); ++card_index) {
1035 const DeviceSpec spec{ InputSourceType::ALSA_INPUT, card_index };
1036 const ALSAPool::Device &device = available_alsa_devices[card_index];
1038 info.display_name = device.display_name();
1039 info.num_channels = device.num_channels;
1040 info.alsa_name = device.name;
1041 info.alsa_info = device.info;
1042 info.alsa_address = device.address;
1043 devices.insert(make_pair(spec, info));
1045 for (unsigned card_index = 0; card_index < num_ffmpeg_inputs; ++card_index) {
1046 const DeviceSpec spec{ InputSourceType::FFMPEG_VIDEO_INPUT, card_index };
1047 const AudioDevice *device = &ffmpeg_inputs[card_index];
1049 info.display_name = device->display_name;
1050 info.num_channels = 2;
1051 devices.insert(make_pair(spec, info));
1056 void AudioMixer::set_display_name(DeviceSpec device_spec, const string &name)
1058 AudioDevice *device = find_audio_device(device_spec);
1060 lock_guard<timed_mutex> lock(audio_mutex);
1061 device->display_name = name;
1064 void AudioMixer::serialize_device(DeviceSpec device_spec, DeviceSpecProto *device_spec_proto)
1066 lock_guard<timed_mutex> lock(audio_mutex);
1067 switch (device_spec.type) {
1068 case InputSourceType::SILENCE:
1069 device_spec_proto->set_type(DeviceSpecProto::SILENCE);
1071 case InputSourceType::CAPTURE_CARD:
1072 device_spec_proto->set_type(DeviceSpecProto::CAPTURE_CARD);
1073 device_spec_proto->set_index(device_spec.index);
1074 device_spec_proto->set_display_name(video_cards[device_spec.index].display_name);
1076 case InputSourceType::ALSA_INPUT:
1077 alsa_pool.serialize_device(device_spec.index, device_spec_proto);
1079 case InputSourceType::FFMPEG_VIDEO_INPUT:
1080 device_spec_proto->set_type(DeviceSpecProto::FFMPEG_VIDEO_INPUT);
1081 device_spec_proto->set_index(device_spec.index);
1082 device_spec_proto->set_display_name(ffmpeg_inputs[device_spec.index].display_name);
1087 void AudioMixer::set_simple_input(unsigned card_index)
1089 assert(card_index < num_capture_cards + num_ffmpeg_inputs);
1090 InputMapping new_input_mapping;
1091 InputMapping::Bus input;
1092 input.name = "Main";
1093 if (card_index >= num_capture_cards) {
1094 input.device = DeviceSpec{InputSourceType::FFMPEG_VIDEO_INPUT, card_index - num_capture_cards};
1096 input.device = DeviceSpec{InputSourceType::CAPTURE_CARD, card_index};
1098 input.source_channel[0] = 0;
1099 input.source_channel[1] = 1;
1101 new_input_mapping.buses.push_back(input);
1103 lock_guard<timed_mutex> lock(audio_mutex);
1104 current_mapping_mode = MappingMode::SIMPLE;
1105 set_input_mapping_lock_held(new_input_mapping);
1106 fader_volume_db[0] = 0.0f;
1109 unsigned AudioMixer::get_simple_input() const
1111 lock_guard<timed_mutex> lock(audio_mutex);
1112 if (input_mapping.buses.size() == 1 &&
1113 input_mapping.buses[0].device.type == InputSourceType::CAPTURE_CARD &&
1114 input_mapping.buses[0].source_channel[0] == 0 &&
1115 input_mapping.buses[0].source_channel[1] == 1) {
1116 return input_mapping.buses[0].device.index;
1117 } else if (input_mapping.buses.size() == 1 &&
1118 input_mapping.buses[0].device.type == InputSourceType::FFMPEG_VIDEO_INPUT &&
1119 input_mapping.buses[0].source_channel[0] == 0 &&
1120 input_mapping.buses[0].source_channel[1] == 1) {
1121 return input_mapping.buses[0].device.index + num_capture_cards;
1123 return numeric_limits<unsigned>::max();
1127 void AudioMixer::set_input_mapping(const InputMapping &new_input_mapping)
1129 lock_guard<timed_mutex> lock(audio_mutex);
1130 set_input_mapping_lock_held(new_input_mapping);
1131 current_mapping_mode = MappingMode::MULTICHANNEL;
1134 AudioMixer::MappingMode AudioMixer::get_mapping_mode() const
1136 lock_guard<timed_mutex> lock(audio_mutex);
1137 return current_mapping_mode;
1140 void AudioMixer::set_input_mapping_lock_held(const InputMapping &new_input_mapping)
1142 map<DeviceSpec, set<unsigned>> interesting_channels;
1143 for (const InputMapping::Bus &bus : new_input_mapping.buses) {
1144 if (bus.device.type == InputSourceType::CAPTURE_CARD ||
1145 bus.device.type == InputSourceType::ALSA_INPUT ||
1146 bus.device.type == InputSourceType::FFMPEG_VIDEO_INPUT) {
1147 for (unsigned channel = 0; channel < 2; ++channel) {
1148 if (bus.source_channel[channel] != -1) {
1149 interesting_channels[bus.device].insert(bus.source_channel[channel]);
1153 assert(bus.device.type == InputSourceType::SILENCE);
1157 // Kill all the old metrics, and set up new ones.
1158 for (unsigned bus_index = 0; bus_index < input_mapping.buses.size(); ++bus_index) {
1159 BusMetrics &metrics = bus_metrics[bus_index];
1161 vector<pair<string, string>> labels_left = metrics.labels;
1162 labels_left.emplace_back("channel", "left");
1163 vector<pair<string, string>> labels_right = metrics.labels;
1164 labels_right.emplace_back("channel", "right");
1166 global_metrics.remove("bus_current_level_dbfs", labels_left);
1167 global_metrics.remove("bus_current_level_dbfs", labels_right);
1168 global_metrics.remove("bus_peak_level_dbfs", labels_left);
1169 global_metrics.remove("bus_peak_level_dbfs", labels_right);
1170 global_metrics.remove("bus_historic_peak_dbfs", metrics.labels);
1171 global_metrics.remove("bus_gain_staging_db", metrics.labels);
1172 global_metrics.remove("bus_compressor_attenuation_db", metrics.labels);
1174 bus_metrics.reset(new BusMetrics[new_input_mapping.buses.size()]);
1175 for (unsigned bus_index = 0; bus_index < new_input_mapping.buses.size(); ++bus_index) {
1176 const InputMapping::Bus &bus = new_input_mapping.buses[bus_index];
1177 BusMetrics &metrics = bus_metrics[bus_index];
1179 char bus_index_str[16], source_index_str[16], source_channels_str[64];
1180 snprintf(bus_index_str, sizeof(bus_index_str), "%u", bus_index);
1181 snprintf(source_index_str, sizeof(source_index_str), "%u", bus.device.index);
1182 snprintf(source_channels_str, sizeof(source_channels_str), "%d:%d", bus.source_channel[0], bus.source_channel[1]);
1184 vector<pair<string, string>> labels;
1185 metrics.labels.emplace_back("index", bus_index_str);
1186 metrics.labels.emplace_back("name", bus.name);
1187 if (bus.device.type == InputSourceType::SILENCE) {
1188 metrics.labels.emplace_back("source_type", "silence");
1189 } else if (bus.device.type == InputSourceType::CAPTURE_CARD) {
1190 metrics.labels.emplace_back("source_type", "capture_card");
1191 } else if (bus.device.type == InputSourceType::ALSA_INPUT) {
1192 metrics.labels.emplace_back("source_type", "alsa_input");
1193 } else if (bus.device.type == InputSourceType::FFMPEG_VIDEO_INPUT) {
1194 metrics.labels.emplace_back("source_type", "ffmpeg_video_input");
1198 metrics.labels.emplace_back("source_index", source_index_str);
1199 metrics.labels.emplace_back("source_channels", source_channels_str);
1201 vector<pair<string, string>> labels_left = metrics.labels;
1202 labels_left.emplace_back("channel", "left");
1203 vector<pair<string, string>> labels_right = metrics.labels;
1204 labels_right.emplace_back("channel", "right");
1206 global_metrics.add("bus_current_level_dbfs", labels_left, &metrics.current_level_dbfs[0], Metrics::TYPE_GAUGE);
1207 global_metrics.add("bus_current_level_dbfs", labels_right, &metrics.current_level_dbfs[1], Metrics::TYPE_GAUGE);
1208 global_metrics.add("bus_peak_level_dbfs", labels_left, &metrics.peak_level_dbfs[0], Metrics::TYPE_GAUGE);
1209 global_metrics.add("bus_peak_level_dbfs", labels_right, &metrics.peak_level_dbfs[1], Metrics::TYPE_GAUGE);
1210 global_metrics.add("bus_historic_peak_dbfs", metrics.labels, &metrics.historic_peak_dbfs, Metrics::TYPE_GAUGE);
1211 global_metrics.add("bus_gain_staging_db", metrics.labels, &metrics.gain_staging_db, Metrics::TYPE_GAUGE);
1212 global_metrics.add("bus_compressor_attenuation_db", metrics.labels, &metrics.compressor_attenuation_db, Metrics::TYPE_GAUGE);
1215 // Reset resamplers for all cards that don't have the exact same state as before.
1216 for (unsigned card_index = 0; card_index < MAX_VIDEO_CARDS; ++card_index) {
1217 const DeviceSpec device_spec{InputSourceType::CAPTURE_CARD, card_index};
1218 AudioDevice *device = find_audio_device(device_spec);
1219 if (device->interesting_channels != interesting_channels[device_spec]) {
1220 device->interesting_channels = interesting_channels[device_spec];
1221 reset_resampler_mutex_held(device_spec);
1224 for (unsigned card_index = 0; card_index < MAX_ALSA_CARDS; ++card_index) {
1225 const DeviceSpec device_spec{InputSourceType::ALSA_INPUT, card_index};
1226 AudioDevice *device = find_audio_device(device_spec);
1227 if (interesting_channels[device_spec].empty()) {
1228 alsa_pool.release_device(card_index);
1230 alsa_pool.hold_device(card_index);
1232 if (device->interesting_channels != interesting_channels[device_spec]) {
1233 device->interesting_channels = interesting_channels[device_spec];
1234 alsa_pool.reset_device(device_spec.index);
1235 reset_resampler_mutex_held(device_spec);
1238 for (unsigned card_index = 0; card_index < num_ffmpeg_inputs; ++card_index) {
1239 const DeviceSpec device_spec{InputSourceType::FFMPEG_VIDEO_INPUT, card_index};
1240 AudioDevice *device = find_audio_device(device_spec);
1241 if (device->interesting_channels != interesting_channels[device_spec]) {
1242 device->interesting_channels = interesting_channels[device_spec];
1243 reset_resampler_mutex_held(device_spec);
1247 input_mapping = new_input_mapping;
1250 InputMapping AudioMixer::get_input_mapping() const
1252 lock_guard<timed_mutex> lock(audio_mutex);
1253 return input_mapping;
1256 unsigned AudioMixer::num_buses() const
1258 lock_guard<timed_mutex> lock(audio_mutex);
1259 return input_mapping.buses.size();
1262 void AudioMixer::reset_peak(unsigned bus_index)
1264 lock_guard<timed_mutex> lock(audio_mutex);
1265 for (unsigned channel = 0; channel < 2; ++channel) {
1266 PeakHistory &history = peak_history[bus_index][channel];
1267 history.current_level = 0.0f;
1268 history.historic_peak = 0.0f;
1269 history.current_peak = 0.0f;
1270 history.last_peak = 0.0f;
1271 history.age_seconds = 0.0f;
1275 bool AudioMixer::is_mono(unsigned bus_index)
1277 lock_guard<timed_mutex> lock(audio_mutex);
1278 const InputMapping::Bus &bus = input_mapping.buses[bus_index];
1279 if (bus.device.type == InputSourceType::SILENCE) {
1282 assert(bus.device.type == InputSourceType::CAPTURE_CARD ||
1283 bus.device.type == InputSourceType::ALSA_INPUT ||
1284 bus.device.type == InputSourceType::FFMPEG_VIDEO_INPUT);
1285 return bus.source_channel[0] == bus.source_channel[1];
1289 AudioMixer *global_audio_mixer = nullptr;