[#5571] Integrate mime types and codec factory

sflphone-common/src/Codec.h

+/*
+ *  Copyright (C) 2004, 2005, 2006, 2009, 2008, 2009, 2010 Savoir-Faire Linux Inc.
+ *  Author: Pierre-Luc Bacon <pierre-luc.bacon@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.
+ *
+ *  Additional permission under GNU GPL version 3 section 7:
+ *
+ *  If you modify this program, or any covered work, by linking or
+ *  combining it with the OpenSSL project's OpenSSL library (or a
+ *  modified version of that library), containing parts covered by the
+ *  terms of the OpenSSL or SSLeay licenses, Savoir-Faire Linux Inc.
+ *  grants you additional permission to convey the resulting work.
+ *  Corresponding Source for a non-source form of such a combination
+ *  shall include the source code for the parts of OpenSSL used as well
+ *  as that of the covered work.
+ */
+
+#ifndef __SFL_CODEC_H__
+#define __SFL_CODEC_H__
+
+#include "MimeParameters.h" // TODO Move to some higher directory
+
+#include <tr1/memory>
+
+#include <cc++/digest.h>
+
+/**
+ * Interface for both audio codecs as well as video codecs.
+ */
+namespace sfl {
+class Codec : public virtual MimeParameters
+{
+    public:
+        Codec() {};
+        virtual inline ~Codec() {}
+
+        /**
+         * @return The bitrate for which this codec is configured // TODO deal with VBR case.
+         */
+        virtual double getBitRate() const = 0;
+
+        /**
+         * @return The expected bandwidth used by this codec.
+         */
+        virtual double getBandwidth() const = 0;
+
+        /**
+         * @return Additional information (description) about this codec. This is meant to be shown to the user.
+         */
+        virtual std::string getDescription() const = 0;
+
+        /**
+         * @return A copy of the current codec.
+         */
+        virtual Codec* clone() const = 0;
+
+        /**
+         * Build a unique hash code for identifying the codec uniquely.
+         * Note that if multiple implementations of codec are provided,
+         * one should override this function in order to avoid conflicting
+         * hash codes.
+         *
+         * Hash code is a CRC32 digest made from :
+         * MIME "." MIME SUBTYPE "." PAYLOAD TYPE "." PAYLOAD CLOCKRATE
+         *
+         * @return a unique hash code identifying this codec.
+         */
+        virtual std::string hashCode() const {
+            ost::CRC32Digest digest;
+
+            std::ostringstream os;
+            os << getMimeType()
+            << "." << getMimeSubtype()
+            << "." << getPayloadType()
+            << "." << getClockRate();
+
+            std::string concat = os.str();
+
+            digest.putDigest ( (const unsigned char*) concat.c_str(), concat.length());
+
+            std::ostringstream buffer;
+            buffer << digest;
+
+            return buffer.str();
+        }
+
+        void setState(bool state) { _state = state; }
+
+        bool getState(void) { return _state; }
+
+    private:
+
+        bool _state;
+
+};
+}
+
+typedef sfl::Codec* create_t();
+
+typedef void destroy_t (sfl::Codec*);
+
+#endif

sflphone-common/src/MimeParameters.h

+/*
+ *  Copyright (C) 2004, 2005, 2006, 2009, 2008, 2009, 2010 Savoir-Faire Linux Inc.
+ *  Author: Pierre-Luc Bacon <pierre-luc.bacon@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.
+ *
+ *  Additional permission under GNU GPL version 3 section 7:
+ *
+ *  If you modify this program, or any covered work, by linking or
+ *  combining it with the OpenSSL project's OpenSSL library (or a
+ *  modified version of that library), containing parts covered by the
+ *  terms of the OpenSSL or SSLeay licenses, Savoir-Faire Linux Inc.
+ *  grants you additional permission to convey the resulting work.
+ *  Corresponding Source for a non-source form of such a combination
+ *  shall include the source code for the parts of OpenSSL used as well
+ *  as that of the covered work.
+ */
+
+#ifndef __SFL_MIME_PARAMETERS_H__
+#define __SFL_MIME_PARAMETERS_H__
+
+/**
+ * Start a new payload format definition.
+ */
+#define MIME_PAYLOAD_FORMAT_DEFINITION( mime, subtype, payloadType, clock ) \
+		private: \
+			uint8 payload; \
+		public: \
+		inline virtual ~MimeParameters##subtype() {}; \
+        std::string getMimeType() const { \
+            return std::string( mime ); \
+        } \
+        std::string getMimeSubtype() const { \
+            return std::string( #subtype ); \
+        } \
+        uint8 getPayloadType() const { \
+            return payload; \
+        } \
+        void setPayloadType(uint8 pt) { \
+			payload = pt; \
+		} \
+        uint32 getClockRate() const { \
+            return clock; \
+        } \
+	    MimeParameters##subtype() : payload(payloadType) {
+
+/**
+ * An alias for MIME_PARAMETER_OPTIONAL
+ */
+#define MIME_PARAMETER(name, handler)	\
+	addOptionalParameter( name ); \
+	addHandler( name, handler );
+
+/**
+ * Defines an optional parameter.
+ */
+#define MIME_PARAMETER_OPTIONAL(name, handler) \
+	addOptionalParameter( name ); \
+	addHandler( name, handler );
+
+/**
+ * Defines a required parameter. The value of this parameter
+ * should be obtained when sending the initial SDP offer.
+ */
+#define MIME_PARAMETER_REQUIRED(name, handler) \
+	addRequiredParameter( name ); \
+	addHandler( name, handler );
+
+/**
+ * End a payload format definition.
+ */
+#define MIME_PAYLOAD_FORMAT_DEFINITION_END() \
+        }
+
+#define MIME_PARAMETER_KEEP_IF_EQUAL MimeParameters::addParameterIfEqual
+
+#define MIME_PARAMETER_KEEP_MINIMUM MimeParameters::addParameterMinimum
+
+#define MIME_PARAMETER_KEEP_REMOTE MimeParameters::addParameterRemote
+
+#include "sip/Fmtp.h"
+
+#include <ccrtp/rtp.h>
+#include <algorithm>
+#include <stdexcept>
+#include <vector>
+#include <map>
+#include <errno.h>
+
+namespace sfl
+{
+
+/**
+ * This exception is thrown in cases where a given format cannot
+ * be parsed, or required pieces of information are missing.
+ */
+class SdpFormatNegotiationException: public std::runtime_error
+{
+	public:
+	SdpFormatNegotiationException (const std::string& msg) : std::runtime_error (msg) {}
+};
+
+/**
+ * Interface for exposing MIME parameters in SDP offer/answer model.
+ */
+class MimeParameters
+{
+    public:
+        /**
+         * @return The mimesubtype for this codec. Eg. : "video"
+         */
+        virtual std::string getMimeType() const = 0;
+
+        /**
+         * @return The mimesubtype for this codec. Eg. : "theora"
+         */
+        virtual std::string getMimeSubtype() const = 0;
+
+        /**
+         * @return payload type numeric identifier.
+         */
+        virtual uint8 getPayloadType() const = 0;
+
+        /**
+         * @param payload The new payload to set
+         */
+        virtual void setPayloadType(uint8 payload) = 0;
+
+        /**
+         * @return RTP clock rate in Hz.
+         */
+        virtual uint32 getClockRate() const = 0;
+
+        /**
+         * @param name The name that identifies the MIME parameter.
+         * @param value The value this parameter should have.
+         */
+        virtual void setParameter (const std::string& name, const std::string& value) = 0;
+
+        /**
+         * @param name The name that identifies the MIME parameter.
+         * @return The value that is set for this parameter.
+         */
+        virtual std::string getParameter (const std::string& name) = 0;
+
+        /**
+         * @return A string containing the codec specific parameters, formatted by default as :
+         * "PARAM_LIST : PARAM_NAME = VALUE SEMI_COLON PARAM_LIST | PARAM_END
+         *  PARAM_END : empty"
+         */
+        virtual std::string getParametersFormatted() {
+        	// TODO Instead of putting everything into the same vector,
+        	// enforce the required vs optional aspect. Unfilled required params. should
+        	// result in exception throwing.
+        	std::vector<std::string> paramList = requiredParameters;
+        	std::copy(optionalParameters.begin(), optionalParameters.end(), std::back_inserter(paramList));
+
+        	std::string output("");
+        	std::vector<std::string>::iterator it;
+        	int numberParamsAppended = 0;
+        	for (it = paramList.begin(); it != paramList.end(); it++) {
+
+        		std::string name = *it;
+        		std::string value = getParameter(name);
+        		if (value != "") {
+        	   		if (numberParamsAppended != 0) {
+        	        	output.append("; ");
+        	        }
+
+        	   		output.append(name + "=" + value);
+
+        	   		numberParamsAppended += 1;
+        		}
+        	}
+
+        	return output;
+        }
+
+        /**
+         * Calls #setParameter() in a loop for every parameters of the format object.
+         * @param format The format object containing the parameters to set.
+         */
+        void setParameters(const sfl::Fmtp& format) {
+        	sfl::Fmtp::const_iterator it;
+        	for (it = format.begin(); it != format.end(); it++) {
+        		_info("****************** Setting parameters");
+        		setParameter((*it).first, (*it).second);
+        	}
+        }
+
+        void setNegotiatedParameters(const sfl::Fmtp& format) {
+        	negotiatedFormat = format;
+        }
+
+        void applyNegotiatedParameters() {
+        	setParameters(negotiatedFormat);
+        }
+
+    protected:
+        sfl::Fmtp negotiatedFormat;
+
+        /**
+         * @param name The name for the required parameter to add.
+         */
+        void addRequiredParameter(const std::string& name) {
+        	requiredParameters.push_back(name);
+        }
+        std::vector<std::string> requiredParameters;
+
+        /**
+         * @param name The name for the optional parameter to add.
+         */
+        void addOptionalParameter(const std::string& name) {
+        	optionalParameters.push_back(name);
+        }
+        std::vector<std::string> optionalParameters;
+
+        /**
+         * Negotiation handler type.
+         * @param localParam The local parameter.
+         * @param remoteParam The remote parameter.
+         * @param offerer The specified format for the offerer.
+         * @param answerer The specified format for the answerer.
+         * @param negotiatedFmtp The format in which to make changes, if any.
+         * @throw SdpFormatNegotiationException if the format can't be processed because of missing options,
+         * or wrong formatting.
+         */
+        typedef void (*ParameterNegotiationHandler)(
+        		const sfl::SdpParameter& localParam,
+        		const sfl::SdpParameter& remoteParam,
+        		const sfl::Fmtp& offerer,
+        		const sfl::Fmtp& answerer,
+        		sfl::Fmtp& negotiatedFmtp);
+
+        std::map<std::string, ParameterNegotiationHandler> parameterHandlerTable;
+
+        typedef std::pair<std::string, ParameterNegotiationHandler> ParameterHandlerEntry;
+
+        typedef std::map<std::string, ParameterNegotiationHandler>::iterator ParameterHandlerIterator;
+
+        /**
+         * Add a negotiation handler for the given property.
+         * @param name The parameter name (eg: "profile-level-id")
+         * @param handler A pointer to the negotiation handler function;
+         */
+        void addHandler(const std::string& name, ParameterNegotiationHandler handler) {
+        	parameterHandlerTable.insert(ParameterHandlerEntry(name, handler));
+        }
+
+    public:
+
+        /**
+         * The default behavior if this method is not overriden is to return the format from
+         * the answerer.
+         * @param offerer The specified format for the offerer.
+         * @param answerer The specified format for the answerer.
+         * @return A format object containing the negotiated format.
+         * @throw SdpFormatNegotiationException if the format can't be processed because of missing options,
+         * or wrong formatting.
+         */
+        virtual sfl::Fmtp negotiate(const sfl::Fmtp& offerer, const sfl::Fmtp& answerer) throw(SdpFormatNegotiationException) {
+        	sfl::Fmtp::iterator itAnswerer;
+
+        	// This object will be built iteratively
+			sfl::Fmtp negotiatedFmtp(offerer.getPayloadType());
+
+			sfl::Fmtp::const_iterator it;
+			// Iterate over all of the properties in the answer
+    		for (it = answerer.begin(); it != answerer.end(); it++) {
+    			std::string propertyName = (*it).first;
+    			std::string valueAnswerer = (*it).second;
+
+    			// Find the corresponding property in the offer
+    			std::string valueOfferer;
+    			sfl::Fmtp::const_iterator itOfferer = offerer.getParameter(propertyName);
+    			if (it == offerer.end()) {
+    				valueOfferer = "";
+    			} else {
+    				valueOfferer = (*itOfferer).second;
+    			}
+
+    			// Find a suitable property handler
+        		ParameterHandlerIterator itHandler = parameterHandlerTable.find(propertyName);
+        		if (itHandler != parameterHandlerTable.end()) {
+        			((*itHandler).second)(sfl::SdpParameter(propertyName, valueOfferer),
+        					sfl::SdpParameter(propertyName, valueAnswerer),
+        					offerer, answerer, negotiatedFmtp);
+        		} else {
+        			_error("Could not find any handler for property \"%s\"", propertyName.c_str());
+        		}
+    		}
+
+    		return negotiatedFmtp;
+    	}
+
+    protected:
+        /**
+         * This handler makes
+         */
+        static void addParameterIfEqual(
+        		const sfl::SdpParameter& localParam,
+        		const sfl::SdpParameter& remoteParam,
+        		const sfl::Fmtp& offerer,
+        		const sfl::Fmtp& answerer,
+        		sfl::Fmtp& negotiatedFmtp)
+        {
+        	if (localParam.getValue() == remoteParam.getValue()) {
+        		negotiatedFmtp[localParam.getName()] = localParam.getValue();
+        	}
+        }
+
+        static void addParameterMinimum(
+        		const sfl::SdpParameter& localParam,
+        		const sfl::SdpParameter& remoteParam,
+        		const sfl::Fmtp& offerer,
+        		const sfl::Fmtp& answerer,
+        		sfl::Fmtp& negotiatedFmtp)
+        {
+    		long int localValue = strtol(localParam.getValue().c_str(), NULL, 16);
+    		if (localValue == 0 && errno == EINVAL) {
+    			// Throw
+    		}
+
+    		long int remoteValue = strtol(remoteParam.getValue().c_str(), NULL, 16);
+    		if (remoteValue == 0 && errno == EINVAL) {
+    			// Throw
+    		}
+
+    		long int minimumValue = std::min(localValue, remoteValue);
+    		negotiatedFmtp[localParam.getName()] = minimumValue;
+        }
+
+        static void addParameterRemote(
+        		const sfl::SdpParameter& localParam,
+        		const sfl::SdpParameter& remoteParam,
+        		const sfl::Fmtp& offerer,
+        		const sfl::Fmtp& answerer,
+        		sfl::Fmtp& negotiatedFmtp)
+        {
+        	negotiatedFmtp[remoteParam.getName()] = remoteParam.getValue();
+        }
+};
+
+}
+#endif

sflphone-common/src/audio/audiortp/AudioRtpRecordHandler.cpp

@@ -130,7 +130,7 @@ void AudioRtpRecordHandler::setRtpMedia (AudioCodec* audioCodec)
 
     // Set varios codec info to reduce indirection
     _audioRtpRecord._audioCodec = audioCodec;
-    _audioRtpRecord._codecPayloadType = audioCodec->getPayload();
+    _audioRtpRecord._codecPayloadType = audioCodec->getPayloadType();
     _audioRtpRecord._codecSampleRate = audioCodec->getClockRate();
     _audioRtpRecord._codecFrameSize = audioCodec->getFrameSize();
     _audioRtpRecord._hasDynamicPayloadType = audioCodec->hasDynamicPayload();
@@ -151,7 +151,7 @@ void AudioRtpRecordHandler::updateRtpMedia (AudioCodec *audioCodec)
     }
 
     _audioRtpRecord._audioCodec = audioCodec;
-    _audioRtpRecord._codecPayloadType = audioCodec->getPayload();
+    _audioRtpRecord._codecPayloadType = audioCodec->getPayloadType();
     _audioRtpRecord._codecSampleRate = audioCodec->getClockRate();
     _audioRtpRecord._codecFrameSize = audioCodec->getFrameSize();
     _audioRtpRecord._hasDynamicPayloadType = audioCodec->hasDynamicPayload();
@@ -297,7 +297,7 @@ int AudioRtpRecordHandler::processDataEncode (void)
 
         _audioRtpRecord.audioCodecMutex.enter();
 
-        compSize = _audioRtpRecord._audioCodec->codecEncode (micDataEncoded, micDataConverted, nbSample * sizeof (SFLDataFormat));
+        compSize = _audioRtpRecord._audioCodec->encode (micDataEncoded, micDataConverted, nbSample * sizeof (SFLDataFormat));
 
         _audioRtpRecord.audioCodecMutex.leave();
 
@@ -313,7 +313,7 @@ int AudioRtpRecordHandler::processDataEncode (void)
         _audioRtpRecord.audioCodecMutex.enter();
 
         // no resampling required
-        compSize = _audioRtpRecord._audioCodec->codecEncode (micDataEncoded, micData, nbSample * sizeof (SFLDataFormat));
+        compSize = _audioRtpRecord._audioCodec->encode (micDataEncoded, micData, nbSample * sizeof (SFLDataFormat));
 
         _audioRtpRecord.audioCodecMutex.leave();
     }
@@ -333,7 +333,7 @@ void AudioRtpRecordHandler::processDataDecode (unsigned char *spkrData, unsigned
     _audioRtpRecord.audioCodecMutex.enter();
 
     // Return the size of data in bytes
-    int expandedSize = _audioRtpRecord._audioCodec->codecDecode (spkrDataDecoded , spkrData , size);
+    int expandedSize = _audioRtpRecord._audioCodec->decode (spkrDataDecoded , spkrData , size);
 
     _audioRtpRecord.audioCodecMutex.leave();
 

sflphone-common/src/audio/codecs/Makefile.am

@@ -2,7 +2,7 @@ include $(top_srcdir)/globals.mak
 
 noinst_LTLIBRARIES = libcodecdescriptor.la
 
-libcodecdescriptor_la_SOURCES = codecDescriptor.cpp 
+libcodecdescriptor_la_SOURCES = codecDescriptor.cpp audiocodec.cpp
 
 if BUILD_GSM
 GSM_LIB = libcodec_gsm.so
@@ -10,6 +10,7 @@ libcodec_gsm_so_SOURCES = gsmcodec.cpp
 libcodec_gsm_so_CFLAGS = -fPIC -g -Wall
 libcodec_gsm_so_CXXFLAGS = -fPIC -g -Wall
 libcodec_gsm_so_LDFLAGS = --shared -lc -lgsm
+libcodec_gsm_so_LDADD = libcodecdescriptor.la
 INSTALL_GSM_RULE = install-libcodec_gsm_so
 endif
 
@@ -19,6 +20,7 @@ libcodec_speex_nb_so_SOURCES = speexcodec_nb.cpp
 libcodec_speex_nb_so_CFLAGS = -fPIC -g -Wall
 libcodec_speex_nb_so_CXXFLAGS = -fPIC -g -Wall $(SPEEXDSP)
 libcodec_speex_nb_so_LDFLAGS = --shared -lc -lspeex $(SPEEX_NIMP)
+libcodec_speex_nb_so_LDADD = libcodecdescriptor.la
 INSTALL_SPEEX_NB_RULE = install-libcodec_speex_nb_so
 endif
 
@@ -28,6 +30,7 @@ libcodec_speex_wb_so_SOURCES = speexcodec_wb.cpp
 libcodec_speex_wb_so_CFLAGS = -fPIC -g -Wall
 libcodec_speex_wb_so_CXXFLAGS = -fPIC -g -Wall $(SPEEXDSP)
 libcodec_speex_wb_so_LDFLAGS = --shared -lc -lspeex $(SPEEX_NIMP)
+libcodec_speex_wb_so_LDADD = libcodecdescriptor.la
 INSTALL_SPEEX_WB_RULE = install-libcodec_speex_wb_so
 endif
 
@@ -37,6 +40,7 @@ libcodec_speex_ub_so_SOURCES = speexcodec_ub.cpp
 libcodec_speex_ub_so_CFLAGS = -fPIC -g -Wall
 libcodec_speex_ub_so_CXXFLAGS = -fPIC -g -Wall $(SPEEXDSP)
 libcodec_speex_ub_so_LDFLAGS = --shared -lc -lspeex $(SPEEX_NIMP)
+libcodec_speex_ub_so_LDADD = libcodecdescriptor.la
 INSTALL_SPEEX_UB_RULE = install-libcodec_speex_ub_so
 endif
 
@@ -46,6 +50,7 @@ libcodec_celt_so_SOURCES = celtcodec.cpp
 libcodec_celt_so_CFLAGS = -fPIC -g -Wall -DBUILD_CELT_91
 libcodec_celt_so_CXXFLAGS = -fPIC -g -Wall -DBUILD_CELT_91
 libcodec_celt_so_LDFLAGS = --shared -lc -lcelt0 $(CELT_NIMP)
+libcodec_celt_so_LDADD = libcodecdescriptor.la
 INSTALL_CELT_RULE = install-libcodec_celt_so
 endif
 
@@ -55,6 +60,7 @@ libcodec_celt_so_SOURCES = celtcodec.cpp
 libcodec_celt_so_CFLAGS = -fPIC -g -Wall -DBUILD_CELT_71
 libcodec_celt_so_CXXFLAGS = -fPIC -g -Wall -DBUILD_CELT_71
 libcodec_celt_so_LDFLAGS = --shared -lc -lcelt0 $(CELT_NIMP)
+libcodec_celt_so_LDADD = libcodecdescriptor.la
 INSTALL_CELT_RULE = install-libcodec_celt_so
 endif
 
@@ -65,16 +71,19 @@ noinst_HEADERS = audiocodec.h codecDescriptor.h
 libcodec_ulaw_so_SOURCES = ulaw.cpp
 libcodec_ulaw_so_CFLAGS = -fPIC -g -Wall
 libcodec_ulaw_so_CXXFLAGS = -fPIC -g -Wall
+libcodec_ulaw_so_LDADD = libcodecdescriptor.la
 libcodec_ulaw_so_LDFLAGS = --shared -lc
 
 libcodec_alaw_so_SOURCES = alaw.cpp
 libcodec_alaw_so_CFLAGS = -fPIC -g -Wall
 libcodec_alaw_so_CXXFLAGS = -fPIC -g -Wall
+libcodec_alaw_so_LDADD = libcodecdescriptor.la
 libcodec_alaw_so_LDFLAGS = --shared -lc
 
 libcodec_g722_so_SOURCES = g722.cpp
 libcodec_g722_so_CFLAGS = -fPIC -g -Wall
 libcodec_g722_so_CXXFLAGS = -fPIC -g -Wall
+libcodec_g722_so_LDADD = libcodecdescriptor.la
 libcodec_g722_so_LDFLAGS = --shared -lc
 
 install-exec-local:  install-libcodec_ulaw_so install-libcodec_alaw_so install-libcodec_g722_so $(INSTALL_GSM_RULE) $(INSTALL_SPEEX_NB_RULE) $(INSTALL_SPEEX_WB_RULE) $(INSTALL_SPEEX_UB_RULE) $(INSTALL_CELT_RULE) $(INSTALL_ILBC_RULE) 

sflphone-common/src/audio/codecs/alaw.cpp

@@ -49,7 +49,7 @@ class Alaw : public AudioCodec
 
         virtual ~Alaw() {}
 
-        virtual int codecDecode (short *dst, unsigned char *src, unsigned int size) {
+        virtual int decode (short *dst, unsigned char *src, unsigned int size) {
             int16* end = dst+size;
 
             while (dst<end)
@@ -58,7 +58,7 @@ class Alaw : public AudioCodec
             return size<<1;
         }
 
-        virtual int codecEncode (unsigned char *dst, short *src, unsigned int size) {
+        virtual int encode (unsigned char *dst, short *src, unsigned int size) {
             size >>= 1;
             uint8* end = dst+size;
 
@@ -129,16 +129,30 @@ class Alaw : public AudioCodec
 
             return a^0x55; // A-law has alternate bits inverted for transmission
         }
+        /**
+         * @Override
+         */
+        std::string getDescription() const {
+            return "audio/PCMA 8000 (\"alaw\") codec.";
+        }
+
+        /**
+         * @Override
+         */
+        Alaw* clone() const {
+            return new Alaw (*this);
+        }
+
 
 };
 
 // the class factories
-extern "C" AudioCodec* create()
+extern "C" sfl::Codec* create()
 {
     return new Alaw (8);
 }
 
-extern <