settings.fader_volume_db = 0.0f;
settings.muted = false;
settings.locut_enabled = global_flags.locut_enabled;
+ settings.stereo_width = 1.0f;
for (unsigned band_index = 0; band_index < NUM_EQ_BANDS; ++band_index) {
settings.eq_level_db[band_index] = 0.0f;
}
settings.fader_volume_db = fader_volume_db[bus_index];
settings.muted = mute[bus_index];
settings.locut_enabled = locut_enabled[bus_index];
+ settings.stereo_width = stereo_width[bus_index];
for (unsigned band_index = 0; band_index < NUM_EQ_BANDS; ++band_index) {
settings.eq_level_db[band_index] = eq_level_db[bus_index][band_index];
}
fader_volume_db[bus_index] = settings.fader_volume_db;
mute[bus_index] = settings.muted;
locut_enabled[bus_index] = settings.locut_enabled;
+ stereo_width[bus_index] = settings.stereo_width;
for (unsigned band_index = 0; band_index < NUM_EQ_BANDS; ++band_index) {
eq_level_db[bus_index][band_index] = settings.eq_level_db[band_index];
}
}
// TODO: Can be SSSE3-optimized if need be.
-void AudioMixer::fill_audio_bus(const map<DeviceSpec, vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output)
+void AudioMixer::fill_audio_bus(const map<DeviceSpec, vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float stereo_width, float *output)
{
if (bus.device.type == InputSourceType::SILENCE) {
memset(output, 0, num_samples * 2 * sizeof(*output));
float *dptr = output;
find_sample_src_from_device(samples_card, bus.device, bus.source_channel[0], &lsrc, &lstride);
find_sample_src_from_device(samples_card, bus.device, bus.source_channel[1], &rsrc, &rstride);
- for (unsigned i = 0; i < num_samples; ++i) {
- *dptr++ = *lsrc;
- *dptr++ = *rsrc;
- lsrc += lstride;
- rsrc += rstride;
+
+ // Apply stereo width settings. Set stereo width w to a 0..1 range instead of
+ // -1..1, since it makes for much easier calculations (so 0.5 = completely mono).
+ // Then, what we want is
+ //
+ // L' = wL + (1-w)R = R + w(L-R)
+ // R' = wR + (1-w)L = L + w(R-L)
+ //
+ // This can be further simplified calculation-wise by defining the weighted
+ // difference signal D = w(R-L), so that:
+ //
+ // L' = R - D
+ // R' = L + D
+ float w = 0.5f * stereo_width + 0.5f;
+ if (bus.source_channel[0] == bus.source_channel[1]) {
+ // Mono anyway, so no need to bother.
+ w = 1.0f;
+ } else if (fabs(w) < 1e-3) {
+ // Perfect inverse.
+ swap(lsrc, rsrc);
+ swap(lstride, rstride);
+ w = 1.0f;
+ }
+ if (fabs(w - 1.0f) < 1e-3) {
+ // No calculations needed for stereo_width = 1.
+ for (unsigned i = 0; i < num_samples; ++i) {
+ *dptr++ = *lsrc;
+ *dptr++ = *rsrc;
+ lsrc += lstride;
+ rsrc += rstride;
+ }
+ } else {
+ // General case.
+ for (unsigned i = 0; i < num_samples; ++i) {
+ float left = *lsrc, right = *rsrc;
+ float diff = w * (right - left);
+ *dptr++ = right - diff;
+ *dptr++ = left + diff;
+ lsrc += lstride;
+ rsrc += rstride;
+ }
}
}
}
samples_out.resize(num_samples * 2);
samples_bus.resize(num_samples * 2);
for (unsigned bus_index = 0; bus_index < input_mapping.buses.size(); ++bus_index) {
- fill_audio_bus(samples_card, input_mapping.buses[bus_index], num_samples, &samples_bus[0]);
+ fill_audio_bus(samples_card, input_mapping.buses[bus_index], num_samples, stereo_width[bus_index], &samples_bus[0]);
apply_eq(bus_index, &samples_bus);
{
void AudioMixer::set_simple_input(unsigned card_index)
{
+ assert(card_index < num_capture_cards + num_ffmpeg_inputs);
InputMapping new_input_mapping;
InputMapping::Bus input;
input.name = "Main";
- input.device.type = InputSourceType::CAPTURE_CARD;
- input.device.index = card_index;
+ if (card_index >= num_capture_cards) {
+ input.device = DeviceSpec{InputSourceType::FFMPEG_VIDEO_INPUT, card_index - num_capture_cards};
+ } else {
+ input.device = DeviceSpec{InputSourceType::CAPTURE_CARD, card_index};
+ }
input.source_channel[0] = 0;
input.source_channel[1] = 1;
input_mapping.buses[0].source_channel[0] == 0 &&
input_mapping.buses[0].source_channel[1] == 1) {
return input_mapping.buses[0].device.index;
+ } else if (input_mapping.buses.size() == 1 &&
+ input_mapping.buses[0].device.type == InputSourceType::FFMPEG_VIDEO_INPUT &&
+ input_mapping.buses[0].source_channel[0] == 0 &&
+ input_mapping.buses[0].source_channel[1] == 1) {
+ return input_mapping.buses[0].device.index + num_capture_cards;
} else {
return numeric_limits<unsigned>::max();
}
}
}
+bool AudioMixer::is_mono(unsigned bus_index)
+{
+ lock_guard<timed_mutex> lock(audio_mutex);
+ const InputMapping::Bus &bus = input_mapping.buses[bus_index];
+ if (bus.device.type == InputSourceType::SILENCE) {
+ return true;
+ } else {
+ assert(bus.device.type == InputSourceType::CAPTURE_CARD ||
+ bus.device.type == InputSourceType::ALSA_INPUT ||
+ bus.device.type == InputSourceType::FFMPEG_VIDEO_INPUT);
+ return bus.source_channel[0] == bus.source_channel[1];
+ }
+}
+
AudioMixer *global_audio_mixer = nullptr;