1 files changed, 353 insertions, 0 deletions

diff --git a/orkaudio/filters/rtpmixer/RtpMixer.cpp b/orkaudio/filters/rtpmixer/RtpMixer.cpp
new file mode 100644
index 0000000..bbba476
--- /dev/null
+++ b/orkaudio/filters/rtpmixer/RtpMixer.cpp
@@ -0,0 +1,353 @@
+/*
+ * Oreka -- A media capture and retrieval platform
+ * 
+ * Copyright (C) 2005, orecx LLC
+ *
+ * http://www.orecx.com
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License.
+ * Please refer to http://www.gnu.org/copyleft/gpl.html
+ *
+ */
+#pragma warning( disable: 4786 )
+
+#ifdef WIN32
+#define __CDECL__ __cdecl
+#else
+#define __CDECL__
+#endif
+#ifdef WIN32
+	#define DLL_EXPORT  __declspec( dllexport )
+#else
+	#define DLL_EXPORT
+#endif
+
+#include <queue>
+#include "Filter.h"
+#include "AudioCapture.h"
+extern "C"
+{
+#include "g711.h"
+}
+
+#define NUM_SAMPLES_CIRCULAR_BUFFER 8000
+#define NUM_SAMPLES_TRIGGER 4000			// when we have this number of available samples make a shipment
+#define NUM_SAMPLES_SHIPMENT_HOLDOFF 2000	// when shipping, ship everything but this number of samples 
+
+
+class RtpMixer : public Filter
+{
+public:
+	RtpMixer();
+
+	FilterRef __CDECL__ Instanciate();
+	void __CDECL__ AudioChunkIn(AudioChunkRef& chunk);
+	void __CDECL__ AudioChunkOut(AudioChunkRef& chunk);
+	AudioEncodingEnum __CDECL__ GetInputAudioEncoding();
+	AudioEncodingEnum __CDECL__ GetOutputAudioEncoding();
+	CStdString __CDECL__ GetName();
+	int __CDECL__ GetInputRtpPayloadType();
+
+private:
+	//AudioChunkRef m_outputAudioChunk;
+	std::queue<AudioChunkRef> m_outputQueue;
+
+	void StoreRtpPacket(AudioChunkRef& chunk);
+	void CreateShipment(size_t silenceSize);
+	unsigned int FreeSpace();
+	unsigned int UsedSpace();
+	short* GetHoldOffPtr();
+	short* CircularPointerAddOffset(short *ptr, size_t offset);
+	short* CicularPointerSubtractOffset(short *ptr, size_t offset);
+
+	short* m_writePtr;		// pointer after newest RTP data we've received
+	short* m_readPtr;		// where to read from next
+	unsigned int m_readTimestamp;	// timestamp that the next shipment will have
+	unsigned int m_writeTimestamp;	// timestamp that the next RTP buffer should have
+	short* m_bufferEnd;
+	short m_buffer[NUM_SAMPLES_CIRCULAR_BUFFER];
+	unsigned int m_shippedSamples;
+
+};
+
+RtpMixer::RtpMixer()
+{
+	m_writePtr = m_buffer;
+	m_readPtr = m_buffer;
+	m_bufferEnd = m_buffer + NUM_SAMPLES_CIRCULAR_BUFFER;
+	m_writeTimestamp = 0;
+	m_readTimestamp = 0;
+	//m_log = Logger::getLogger("rtpringbuffer");
+	m_shippedSamples = 0;
+}
+
+FilterRef RtpMixer::Instanciate()
+{
+	FilterRef Filter(new RtpMixer());
+	return Filter;
+}
+
+void RtpMixer::AudioChunkIn(AudioChunkRef& chunk)
+{	
+	AudioChunkDetails* details = chunk->GetDetails();		
+	if(details->m_encoding != PcmAudio)
+	{
+		throw (CStdString("RtpMixer input audio must be PCM !"));
+	}
+
+	unsigned int rtpEndTimestamp = details->m_timestamp + chunk->GetNumSamples();  // GetNumSamples()  #############################
+
+	if(m_writeTimestamp == 0)
+	{
+		// First RTP packet of the session
+		//LOG4CXX_DEBUG(m_log, m_capturePort + " first packet");
+		m_writeTimestamp = details->m_timestamp;
+		m_readTimestamp = m_writeTimestamp;
+		StoreRtpPacket(chunk);
+	}
+	else if (details->m_timestamp >= m_readTimestamp)	// drop packets that are older than last shipment
+	{
+		if( (int)(rtpEndTimestamp - m_writeTimestamp) <= (int)FreeSpace())
+		{
+			// RTP packet fits into current buffer
+			StoreRtpPacket(chunk);
+
+			if(UsedSpace() > NUM_SAMPLES_TRIGGER)
+			{
+				// We have enough stuff, make a shipment
+				CreateShipment(0);
+			}
+		}
+		else
+		{
+			// RTP packet does not fit into current buffer
+			// work out how much silence we need to add to the current buffer when shipping
+			size_t silenceSize = details->m_timestamp - m_writeTimestamp;
+			CreateShipment(silenceSize);
+
+			// reset buffer
+			m_writePtr = m_buffer;
+			m_readPtr = m_buffer;
+			m_writeTimestamp = details->m_timestamp;
+			m_readTimestamp = m_writeTimestamp;
+
+			// Store new packet
+			StoreRtpPacket(chunk);
+		}
+	}
+	else
+	{
+		//LOG4CXX_DEBUG(m_log, m_capturePort + " packet too old, dropped");
+	}
+	CStdString debug;
+	debug.Format("free:%u used:%u wr:%x rd:%x wrts:%u rdts:%d", FreeSpace(), UsedSpace(), m_writePtr, m_readPtr, m_writeTimestamp, m_readTimestamp);
+	//LOG4CXX_DEBUG(m_log, debug);
+}
+
+void RtpMixer::AudioChunkOut(AudioChunkRef& chunk)
+{
+	if(m_outputQueue.size() > 0)
+	{
+		chunk = m_outputQueue.front();
+		m_outputQueue.pop();
+	}
+	else
+	{
+		chunk.reset();
+	}
+}
+
+AudioEncodingEnum RtpMixer::GetInputAudioEncoding()
+{
+	return PcmAudio;
+}
+
+AudioEncodingEnum RtpMixer::GetOutputAudioEncoding()
+{
+	return PcmAudio;
+}
+
+CStdString RtpMixer::GetName()
+{
+	return "RtpMixer";
+}
+
+
+int RtpMixer::GetInputRtpPayloadType(void)	// does not link if not defined here ?
+{
+	return -1;
+}
+
+// Writes to the internal buffer without any size verification
+void RtpMixer::StoreRtpPacket(AudioChunkRef& audioChunk)
+{
+	CStdString debug;
+	AudioChunkDetails* details = audioChunk->GetDetails();
+
+	// 1. Silence from write pointer until end of RTP packet
+	unsigned int endRtpTimestamp = details->m_timestamp + audioChunk->GetNumSamples();	  // GetNumSamples()  #############################
+	if (endRtpTimestamp > m_writeTimestamp)
+	{
+		for(int i=0; i<(endRtpTimestamp - m_writeTimestamp); i++)
+		{
+			*m_writePtr = 0;
+			m_writePtr++;
+			if(m_writePtr >= m_bufferEnd)
+			{
+				m_writePtr = m_buffer;
+			}
+		}
+		int silenceSize = endRtpTimestamp - m_writeTimestamp;
+		m_writeTimestamp = endRtpTimestamp;
+		debug.Format("Zeroed %d samples, wr:%x wrts:%u", silenceSize, m_writePtr, m_writeTimestamp);
+		//LOG4CXX_DEBUG(m_log, debug);
+	}
+
+	// 2. Mix in the latest samples from this RTP packet
+	unsigned int timestampDelta = m_writeTimestamp - details->m_timestamp;
+	ASSERT(timestampDelta>=0);
+	short* tempWritePtr = CicularPointerSubtractOffset(m_writePtr, timestampDelta);
+	short* payload = (short *)audioChunk->m_pBuffer;	// payload should be short* #################################################
+
+	for(int i=0; i<audioChunk->GetNumSamples() ; i++)	//#################################################
+	{
+		*tempWritePtr += payload[i];
+		tempWritePtr++;
+		if(tempWritePtr >= m_bufferEnd)
+		{
+			tempWritePtr = m_buffer;
+		}
+	}
+	debug.Format("Copied %d samples, tmpwr:%x", audioChunk->GetNumSamples(), tempWritePtr);	//#################################################
+	//LOG4CXX_DEBUG(m_log, debug);
+}
+
+short* RtpMixer::CircularPointerAddOffset(short *ptr, size_t offset)
+{
+	if((ptr + offset) >= m_bufferEnd)
+	{
+		return m_buffer + offset - (m_bufferEnd-ptr);
+	}
+	else
+	{
+		return ptr + offset;
+	}
+}
+
+short* RtpMixer::CicularPointerSubtractOffset(short *ptr, size_t offset)
+{
+	if((ptr-offset) < m_buffer)
+	{
+		return m_bufferEnd - offset + (ptr-m_buffer);
+	}
+	else
+	{
+		return ptr - offset;
+	}
+}
+
+void RtpMixer::CreateShipment(size_t silenceSize)
+{
+	// 1. ship from readPtr until stop pointer or until end of buffer if wrapped
+	bool bufferWrapped = false;
+	short* stopPtr = NULL;
+	short* wrappedStopPtr = NULL;
+	if (silenceSize)
+	{
+		// There is additional silence to ship, do not take holdoff into account
+		stopPtr = m_writePtr;
+	}
+	else
+	{
+		stopPtr = CicularPointerSubtractOffset(m_writePtr, NUM_SAMPLES_SHIPMENT_HOLDOFF);
+	}
+
+	if (stopPtr < m_readPtr)
+	{
+		wrappedStopPtr = stopPtr;
+		stopPtr = m_bufferEnd;
+		bufferWrapped = true;
+	}
+	size_t shortSize = stopPtr-m_readPtr;
+	size_t byteSize = shortSize*2;
+	AudioChunkRef chunk(new AudioChunk());
+	AudioChunkDetails details;
+	details.m_encoding = PcmAudio;
+	chunk->SetBuffer((void*)m_readPtr, byteSize, details);
+	m_outputQueue.push(chunk);
+	m_shippedSamples += shortSize;
+	m_readPtr = CircularPointerAddOffset(m_readPtr ,shortSize);
+	m_readTimestamp += shortSize;
+
+	CStdString debug;
+	debug.Format("Ship %d samples, rd:%x rdts:%u", shortSize, m_readPtr, m_readTimestamp);
+	//LOG4CXX_DEBUG(m_log, debug);
+
+
+	// 2. ship from beginning of buffer until stop ptr
+	if(bufferWrapped) 
+	{
+		shortSize = wrappedStopPtr - m_buffer;
+		byteSize = shortSize*2;
+		chunk.reset(new AudioChunk());
+		AudioChunkDetails details;
+		details.m_encoding = PcmAudio;
+		chunk->SetBuffer((void*)m_buffer, byteSize, details);
+		m_outputQueue.push(chunk);
+		m_shippedSamples += shortSize;
+		m_readPtr = CircularPointerAddOffset(m_readPtr ,shortSize);
+		m_readTimestamp += shortSize;
+		debug.Format("Ship wrapped %d samples, rd:%x rdts:%u", shortSize, m_readPtr, m_readTimestamp);
+		//LOG4CXX_DEBUG(m_log, debug);
+	}
+
+	// 3. ship silence
+	if (silenceSize)
+	{
+		byteSize = silenceSize*2;
+		char* silenceBuffer = (char*)calloc(byteSize, 1);
+		if (silenceBuffer)
+		{
+			AudioChunkRef chunk(new AudioChunk());
+			AudioChunkDetails details;
+			details.m_encoding = PcmAudio;
+			chunk->SetBuffer((void*)silenceBuffer, byteSize, details);
+			m_outputQueue.push(chunk);
+			m_shippedSamples += silenceSize;
+			m_readPtr = CircularPointerAddOffset(m_readPtr ,silenceSize);
+			m_readTimestamp += silenceSize;
+		}
+		debug.Format("Ship %d silence samples, rd:%x rdts:%u", silenceSize, m_readPtr, m_readTimestamp);
+		//LOG4CXX_DEBUG(m_log, debug);
+	}
+}
+
+
+unsigned int RtpMixer::UsedSpace()
+{
+	if(m_writePtr >= m_readPtr)
+	{
+		return m_writePtr - m_readPtr;
+	}
+	return NUM_SAMPLES_CIRCULAR_BUFFER + m_writePtr - m_readPtr;
+}
+
+
+unsigned int RtpMixer::FreeSpace()
+{
+	return NUM_SAMPLES_CIRCULAR_BUFFER - UsedSpace();
+}
+
+
+//=====================================================================
+
+
+extern "C"
+{
+	DLL_EXPORT void __CDECL__ Initialize()
+	{
+		FilterRef filter(new RtpMixer());
+		FilterRegistry::instance()->RegisterFilter(filter);
+	}
+}
\ No newline at end of file