[#2253] Add DcBlocker class to remove capture's dc offset

sflphone-common/src/audio/Makefile.am

@@ -19,6 +19,7 @@ libaudio_la_SOURCES = \
 		audiolayer.cpp \
 		audiodevice.cpp \
 		samplerateconverter.cpp \
+		dcblocker.cpp \
 		$(SPEEX_SOURCES_CPP)
 
 noinst_HEADERS = \
@@ -29,6 +30,7 @@ noinst_HEADERS = \
 		audiodevice.h \
 		mainbuffer.h \
 	 	recordable.h \
+		dcblocker.h \
 		samplerateconverter.h
 
 

sflphone-common/src/audio/alsa/alsalayer.cpp

@@ -46,6 +46,8 @@ AlsaLayer::AlsaLayer (ManagerImpl* manager)
     _audioThread = new AudioThread (this);
 
     _urgentRingBuffer.createReadPointer();
+
+    dcblocker = new DcBlocker();
 }
 
 // Destructor
@@ -57,6 +59,8 @@ AlsaLayer::~AlsaLayer (void)
     if(_converter) {
 	delete _converter; _converter = NULL;
     }
+
+    delete dcblocker; dcblocker = NULL;
 }
 
 bool
@@ -884,6 +888,8 @@ void AlsaLayer::audioCallback (void)
 
 		    nbSample = _converter->downsampleData ((SFLDataFormat*)in, rsmpl_out, _mainBufferSampleRate, _audioSampleRate, nb_sample_up);
 
+		    dcblocker->filter_signal(rsmpl_out, nbSample);
+
 		    _mainBuffer.putData(rsmpl_out, nbSample * sizeof (SFLDataFormat), 100);
 
 		    free(rsmpl_out);

sflphone-common/src/audio/alsa/alsalayer.h

@@ -22,6 +22,7 @@
 
 #include "audio/audiolayer.h"
 #include "audio/samplerateconverter.h"
+#include "audio/dcblocker.h"
 #include "eventthread.h"
 #include <alsa/asoundlib.h>
 
@@ -271,6 +272,8 @@ class AlsaLayer : public AudioLayer {
 
     int _converterSamplingRate;
 
+    DcBlocker* dcblocker;
+
 };
 
 #endif // _ALSA_LAYER_H_

sflphone-common/src/audio/audiolayer.h

@@ -299,6 +299,7 @@ class AudioLayer {
         int _errorMessage;
 
         ost::Mutex _mutex;
+
 };
 
 #endif // _AUDIO_LAYER_H_

sflphone-common/src/audio/dcblocker.cpp

+/*
+ *  Copyright (C) 2009 Savoir-Faire Linux inc.
+ *  Author: Alexandre Savard <alexandre.savard@savoirfairelinux.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+
+#include "dcblocker.h"
+
+DcBlocker::DcBlocker(){
+
+    y = 0;
+    x = 0;
+    xm1 = 0;
+    ym1 = 0;
+
+}
+
+DcBlocker::~DcBlocker(){
+
+   
+}
+
+void DcBlocker::filter_signal(SFLDataFormat* audio_data, int length)
+{
+    // y(n) = x(n) - x(n-1) + R y(n-1) , R = 0.9999
+
+    for(int i = 0; i < length; i++) {
+
+        x = audio_data[i];
+
+        y = (SFLDataFormat)((float)x - (float)xm1 + 0.9999 * (float)ym1);
+        xm1 = x;
+        ym1 = y;
+
+        audio_data[i] = y;
+
+    }
+
+}

sflphone-common/src/audio/dcblocker.h

+/*
+ *  Copyright (C) 2009 Savoir-Faire Linux inc.
+ *  Author: Alexandre Savard <alexandre.savard@savoirfairelinux.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef DCBLOCKER_H
+#define DCBLOCKER_H
+
+#include "global.h"
+
+class DcBlocker {
+
+public:
+
+    DcBlocker();
+
+    ~DcBlocker();
+
+    void filter_signal(SFLDataFormat* audio_data, int length);
+
+private:
+
+    SFLDataFormat y, x, xm1, ym1;
+};
+
+#endif

sflphone-common/src/audio/pulseaudio/pulselayer.cpp

@@ -41,6 +41,7 @@ PulseLayer::PulseLayer (ManagerImpl* manager)
     _debug ("PulseLayer::Pulse audio constructor: Create context\n");
 
     _urgentRingBuffer.createReadPointer();
+    dcblocker = new DcBlocker();
 }
 
 // Destructor
@@ -51,6 +52,8 @@ PulseLayer::~PulseLayer (void)
     if (_converter) {
 	delete _converter; _converter = NULL;
     }
+
+    delete dcblocker; dcblocker = NULL;
 }
 
 bool
@@ -486,6 +489,8 @@ void PulseLayer::readFromMic (void)
             
             nbSample = _converter->downsampleData ((SFLDataFormat*)data, rsmpl_out, _mainBufferSampleRate, _audioSampleRate, nb_sample_up);
 
+	    // remove dc offset
+	    dcblocker->filter_signal( rsmpl_out, nbSample );
 
 	    _mainBuffer.putData ( (void*) rsmpl_out, nbSample*sizeof(SFLDataFormat), 100);
 

sflphone-common/src/audio/pulseaudio/pulselayer.h

@@ -22,6 +22,7 @@
 
 #include "audio/audiolayer.h"
 #include "audio/samplerateconverter.h"
+#include "audio/dcblocker.h"
 #include "audiostream.h"
 
 #include <pulse/pulseaudio.h>
@@ -198,6 +199,8 @@ class PulseLayer : public AudioLayer {
     int spkrVolume;
     int micVolume;
 
+    DcBlocker* dcblocker;
+
     // private:
 
 public: 

sflphone-common/src/sip/sipvoiplink.cpp

@@ -594,8 +594,8 @@ int SIPVoIPLink::sendRegister (AccountID id)
     
     pjsip_tpselector *tp;
 
-    init_transport_selector (account->getAccountTransport (), &tp);
-    status = pjsip_regc_set_transport (regc, tp);
+    // init_transport_selector (account->getAccountTransport (), &tp);
+    // status = pjsip_regc_set_transport (regc, tp);
     
     if (status != PJ_SUCCESS) {
 	_debug ("UserAgent: Unable to set transport.\n");
@@ -1322,9 +1322,9 @@ SIPVoIPLink::SIPStartCall (SIPCall* call, const std::string& subject UNUSED)
     call->setInvSession (inv);
 
 	// Set the appropriate transport
-	pjsip_tpselector *tp;
-	init_transport_selector (account->getAccountTransport (), &tp);
-	status = pjsip_dlg_set_transport (dialog, tp);
+	// pjsip_tpselector *tp;
+	// init_transport_selector (account->getAccountTransport (), &tp);
+	// status = pjsip_dlg_set_transport (dialog, tp);
 
     status = pjsip_inv_send_msg (inv, tdata);