add a new AudioInjector class that can be leveraged from eve and injector

libraries/shared/src/AudioInjector.cpp

@@ -0,0 +1,83 @@
+//
+//  AudioInjector.cpp
+//  hifi
+//
+//  Created by Stephen Birarda on 4/23/13.
+//
+//
+
+#include <sys/time.h>
+#include <fstream>
+
+#include "SharedUtil.h"
+#include "PacketHeaders.h"
+
+#include "AudioInjector.h"
+
+const int BUFFER_LENGTH_BYTES = 512;
+const int BUFFER_LENGTH_SAMPLES = BUFFER_LENGTH_BYTES / sizeof(int16_t);
+const float SAMPLE_RATE = 22050.0;
+const float BUFFER_SEND_INTERVAL_USECS = (BUFFER_LENGTH_SAMPLES / SAMPLE_RATE) * 1000000;
+
+AudioInjector::AudioInjector(const char* filename) :
+    _bearing(0),
+    _attenuationModifier(255)
+{
+    _position[0] = 0.0f;
+    _position[1] = 0.0f;
+    _position[2] = 0.0f;
+    
+    std::fstream sourceFile;
+    
+    sourceFile.open(filename, std::ios::in | std::ios::binary);
+    sourceFile.seekg(0, std::ios::end);
+    
+    _numTotalBytesAudio = sourceFile.tellg();
+    sourceFile.seekg(0, std::ios::beg);
+    long sizeOfShortArray = _numTotalBytesAudio / 2;
+    _audioSampleArray = new int16_t[sizeOfShortArray];
+    
+    sourceFile.read((char *)_audioSampleArray, _numTotalBytesAudio);
+}
+
+AudioInjector::~AudioInjector() {
+    delete[] _audioSampleArray;
+}
+
+void AudioInjector::setPosition(float* position) {
+    _position[0] = position[0];
+    _position[1] = position[1];
+    _position[2] = position[2];
+}
+
+void AudioInjector::injectAudio(UDPSocket *injectorSocket, sockaddr *destinationSocket) {
+    timeval startTime;
+    
+    // one byte for header, 3 positional floats, 1 bearing float, 1 attenuation modifier byte
+    int leadingBytes = 1 + (sizeof(float) * 4) + 1;
+    unsigned char dataPacket[BUFFER_LENGTH_BYTES + leadingBytes];
+    
+    dataPacket[0] = PACKET_HEADER_INJECT_AUDIO;
+    unsigned char *currentPacketPtr = dataPacket + 1;
+    
+    for (int i = 0; i < 3; i++) {
+        memcpy(currentPacketPtr, &_position[i], sizeof(float));
+        currentPacketPtr += sizeof(float);
+    }
+    
+    memcpy(currentPacketPtr, &_bearing, sizeof(float));
+    currentPacketPtr += sizeof(float);
+        
+    *currentPacketPtr = _attenuationModifier;
+    currentPacketPtr++;
+    
+    for (int i = 0; i < _numTotalBytesAudio; i += BUFFER_LENGTH_SAMPLES) {
+        gettimeofday(&startTime, NULL);
+        
+        memcpy(currentPacketPtr, _audioSampleArray + i, BUFFER_LENGTH_BYTES);
+        injectorSocket->send(destinationSocket, dataPacket, sizeof(dataPacket));
+        
+        double usecToSleep = usecTimestamp(&startTime) + BUFFER_SEND_INTERVAL_USECS - usecTimestampNow();
+        usleep(usecToSleep);
+    }
+}

libraries/shared/src/AudioInjector.h

@@ -0,0 +1,35 @@
+//
+//  AudioInjector.h
+//  hifi
+//
+//  Created by Stephen Birarda on 4/23/13.
+//
+//
+
+#ifndef __hifi__AudioInjector__
+#define __hifi__AudioInjector__
+
+#include <iostream>
+#include <netinet/in.h>
+
+#include "UDPSocket.h"
+
+class AudioInjector {
+public:
+    AudioInjector(const char* filename);
+    ~AudioInjector();
+    
+    void setPosition(float* position);
+    void setBearing(float bearing) { _bearing = bearing; }
+    void setAttenuationModifier(unsigned char attenuationModifier) { _attenuationModifier = attenuationModifier; }
+    
+    void injectAudio(UDPSocket* injectorSocket, sockaddr* destinationSocket);
+private:
+    int16_t* _audioSampleArray;
+    int _numTotalBytesAudio;
+    float _position[3];
+    float _bearing;
+    unsigned char _attenuationModifier;
+};
+
+#endif /* defined(__hifi__AudioInjector__) */