#8672: Implement audio gain management in pulseaudio

daemon/src/audio/alsa/alsalayer.cpp

@@ -540,15 +540,6 @@ AlsaLayer::getAudioDeviceIndex(const std::string &description) const
     return 0;
 }
 
-namespace {
-void adjustVolume(SFLDataFormat *src , int samples, int volumePercentage)
-{
-    if (volumePercentage != 100)
-        for (int i = 0 ; i < samples; i++)
-            src[i] = src[i] * volumePercentage * 0.01;
-}
-}
-
 void AlsaLayer::capture()
 {
     unsigned int mainBufferSampleRate = Manager::instance().getMainBuffer()->getInternalSamplingRate();
@@ -575,7 +566,7 @@ void AlsaLayer::capture()
         goto end;
     }
 
-    adjustVolume(in, toGetSamples, getCaptureGain());
+    AudioLayer::applyGain(in, toGetSamples, getCaptureGain());
 
     if (resample) {
         int outSamples = toGetSamples * ((double) audioSampleRate_ / mainBufferSampleRate);
@@ -639,7 +630,7 @@ void AlsaLayer::playback(int maxSamples)
 
     SFLDataFormat *out = (SFLDataFormat*) malloc(toGet);
     Manager::instance().getMainBuffer()->getData(out, toGet);
-    adjustVolume(out, toGet / sizeof(SFLDataFormat), getPlaybackGain());
+    AudioLayer::applyGain(out, toGet / sizeof(SFLDataFormat), getPlaybackGain());
 
     if (resample) {
         int inSamples = toGet / sizeof(SFLDataFormat);
@@ -676,7 +667,7 @@ void AlsaLayer::audioCallback()
 
         SFLDataFormat *out = (SFLDataFormat*) malloc(toGet);
         urgentRingBuffer_.Get(out, toGet);
-        adjustVolume(out, toGet / sizeof(SFLDataFormat), getPlaybackGain());
+        AudioLayer::applyGain(out, toGet / sizeof(SFLDataFormat), getPlaybackGain());
 
         write(out, toGet, playbackHandle_);
         free(out);

daemon/src/audio/audiolayer.cpp

@@ -78,6 +78,13 @@ void AudioLayer::putUrgent(void* buffer, int toCopy)
     urgentRingBuffer_.Put(buffer, toCopy);
 }
 
+void AudioLayer::applyGain(SFLDataFormat *src , int samples, int gain)
+{
+    if (gain != 100)
+        for (int i = 0 ; i < samples; i++)
+            src[i] = src[i] * gain* 0.01;
+}
+
 // Notify (with a beep) an incoming call when there is already a call in progress
 void AudioLayer::notifyincomingCall()
 {

daemon/src/audio/audiolayer.h

@@ -105,6 +105,11 @@ class AudioLayer {
          */
         void flushUrgent();
 
+        /**
+         * Apply gain to audio frame
+         */
+        static void applyGain(SFLDataFormat *src , int samples, int gain);
+        
         /**
          * Set capture stream gain (microphone)
          */

daemon/src/audio/pulseaudio/pulselayer.cpp

@@ -331,6 +331,7 @@ void PulseLayer::writeToSpeaker()
     if (urgentBytes) {
         pa_stream_begin_write(s, &data, &urgentBytes);
         urgentRingBuffer_.Get(data, urgentBytes);
+        applyGain(static_cast<SFLDataFormat *>(data), urgentBytes / sizeof(SFLDataFormat), getPlaybackGain());  
         pa_stream_write(s, data, urgentBytes, NULL, 0, PA_SEEK_RELATIVE);
         // Consume the regular one as well (same amount of bytes)
         Manager::instance().getMainBuffer()->discard(urgentBytes);
@@ -343,6 +344,7 @@ void PulseLayer::writeToSpeaker()
         if (playback_->isReady()) {
             pa_stream_begin_write(s, &data, &bytes);
             toneToPlay->getNext((SFLDataFormat*)data, bytes / sizeof(SFLDataFormat), 100);
+            applyGain(static_cast<SFLDataFormat *>(data), bytes / sizeof(SFLDataFormat), getPlaybackGain());
             pa_stream_write(s, data, bytes, NULL, 0, PA_SEEK_RELATIVE);
         }
 
@@ -388,11 +390,14 @@ void PulseLayer::writeToSpeaker()
     if (resample) {
         SFLDataFormat* rsmpl_out = (SFLDataFormat*) pa_xmalloc(outBytes);
         converter_->resample((SFLDataFormat*)data, rsmpl_out, mainBufferSampleRate, audioSampleRate_, inSamples);
+        applyGain(rsmpl_out, outBytes / sizeof(SFLDataFormat), getPlaybackGain());
         pa_stream_write(s, rsmpl_out, outBytes, NULL, 0, PA_SEEK_RELATIVE);
         pa_xfree(rsmpl_out);
-    } else
+    } else {
+        applyGain(static_cast<SFLDataFormat *>(data), inBytes / sizeof(SFLDataFormat), getPlaybackGain());
         pa_stream_write(s, data, inBytes, NULL, 0, PA_SEEK_RELATIVE);
     }
+}
 
 void PulseLayer::readFromMic()
 {
@@ -455,8 +460,10 @@ void PulseLayer::ringtoneToSpeaker()
     pa_stream_begin_write(s, &data, &bytes);
     AudioLoop *fileToPlay = Manager::instance().getTelephoneFile();
 
-    if (fileToPlay)
+    if (fileToPlay) {
         fileToPlay->getNext((SFLDataFormat *) data, bytes / sizeof(SFLDataFormat), 100);
+        applyGain(static_cast<SFLDataFormat *>(data), bytes / sizeof(SFLDataFormat), getPlaybackGain());
+    }
     else
         memset(data, 0, bytes);