Audio UDP/RTP: fixed A-law / mu-law compressors

sdrbase/audio/audiocompressor.cpp

@@ -86,15 +86,15 @@ void AudioCompressor::fillLUT2()
 
 void AudioCompressor::fillALaw()
 {
-    for (int i=0; i<8*4096; i++) {
-        m_lut[i] = ALaw_Encode(i/2 + 16384);
+    for (int i=-32768; i<32768; i++) {
+        m_lut[i+32768] = ALaw_Encode(i);
     }
 }
 
 void AudioCompressor::fillULaw()
 {
-    for (int i=0; i<8*4096; i++) {
-        m_lut[i] = MuLaw_Encode(i/2 + 16384);
+    for (int i=-32768; i<32768; i++) {
+        m_lut[i+32768] = MuLaw_Encode(i);
     }
 }
 
@@ -107,7 +107,7 @@ int16_t AudioCompressor::compress(int16_t sample)
 
 int8_t AudioCompressor::compress8(int16_t sample)
 {
-    return m_lut[sample/2 + 16384];
+    return m_lut[sample + 32768];
 }
 
 /* http://dystopiancode.blogspot.com/2012/02/pcm-law-and-u-law-companding-algorithms.html

sdrbase/audio/audiocompressor.h

@@ -37,7 +37,7 @@ private:
     int8_t ALaw_Encode(int16_t number);
     int8_t MuLaw_Encode(int16_t number);
 
-    int16_t m_lut[32768];
+    int16_t m_lut[65536];
     static const uint16_t ALAW_MAX;
     static const uint16_t MULAW_MAX;
     static const uint16_t MULAW_BIAS;

sdrgui/gui/audiodialog.cpp

@@ -282,7 +282,7 @@ void AudioDialogX::updateOutputSDPString()
     }
 
     int nChannels = m_outputDeviceInfo.udpChannelMode == AudioOutput::UDPChannelStereo ? 2 : 1;
-
     uint32_t decimationFactor = m_outputDeviceInfo.decimationFactor == 0 ? 1 : m_outputDeviceInfo.decimationFactor;
+
     ui->outputSDPText->setText(tr("%1/%2/%3").arg(format).arg(m_outputDeviceInfo.sampleRate/decimationFactor).arg(nChannels));
 }