When an ALSA input goes away, replace it by silence.

[nageru] / audio_mixer.cpp

diff --git a/audio_mixer.cpp b/audio_mixer.cpp
index 8485d0a6343fec00a97fe2417dd46d7aac0bb248..87a99bddc3c732dc81b29c044306bb739976815b 100644 (file)
--- a/audio_mixer.cpp
+++ b/audio_mixer.cpp
@@ -294,6 +294,22 @@ bool AudioMixer::add_silence(DeviceSpec device_spec, unsigned samples_per_frame,
        return true;
 }
 
+bool AudioMixer::silence_card(DeviceSpec device_spec, bool silence)
+{
+       AudioDevice *device = find_audio_device(device_spec);
+
+       unique_lock<timed_mutex> lock(audio_mutex, defer_lock);
+       if (!lock.try_lock_for(chrono::milliseconds(10))) {
+               return false;
+       }
+
+       if (device->silenced && !silence) {
+               reset_resampler_mutex_held(device_spec);
+       }
+       device->silenced = silence;
+       return true;
+}
+
 AudioMixer::AudioDevice *AudioMixer::find_audio_device(DeviceSpec device)
 {
        switch (device.type) {
@@ -383,11 +399,15 @@ vector<float> AudioMixer::get_output(double pts, unsigned num_samples, Resamplin
        for (const DeviceSpec &device_spec : get_active_devices()) {
                AudioDevice *device = find_audio_device(device_spec);
                samples_card[device_spec].resize(num_samples * device->interesting_channels.size());
-               device->resampling_queue->get_output_samples(
-                       pts,
-                       &samples_card[device_spec][0],
-                       num_samples,
-                       rate_adjustment_policy);
+               if (device->silenced) {
+                       memset(&samples_card[device_spec][0], 0, samples_card[device_spec].size() * sizeof(float));
+               } else {
+                       device->resampling_queue->get_output_samples(
+                               pts,
+                               &samples_card[device_spec][0],
+                               num_samples,
+                               rate_adjustment_policy);
+               }
        }
 
        vector<float> samples_out, left, right;