XnStatus XnSharedMemoryBufferPool::AllocateBuffers()
{
XnStatus nRetVal = XN_STATUS_OK;
if (m_nBufferSize > m_nMaxBufferSize)
{
return XN_STATUS_ALLOC_FAILED;
}
if (m_pSharedMemoryAddress != NULL)
{
// already allocated. nothing to do here
return (XN_STATUS_OK);
}
// first time. allocate shared memory
XnUInt32 nTotalSize = m_nMaxBufferSize * m_nBufferCount;
nRetVal = xnOSCreateSharedMemory(m_strName, nTotalSize, XN_OS_FILE_READ | XN_OS_FILE_WRITE, &m_hSharedMemory);
XN_IS_STATUS_OK(nRetVal);
void* pAddress;
nRetVal = xnOSSharedMemoryGetAddress(m_hSharedMemory, &pAddress);
if (nRetVal != XN_STATUS_OK)
{
xnOSCloseSharedMemory(m_hSharedMemory);
m_hSharedMemory = NULL;
return (nRetVal);
}
m_pSharedMemoryAddress = (XnUChar*)pAddress;
// now allocate buffers
for (XnUInt32 i = 0; i < m_nBufferCount; ++i)
{
XnBufferInPool* pBuffer = XN_NEW(XnBufferInPool);
if (pBuffer == NULL)
{
Free();
return (XN_STATUS_ALLOC_FAILED);
}
pBuffer->m_nID = i;
pBuffer->SetExternalBuffer(m_pSharedMemoryAddress + i*m_nMaxBufferSize, m_nMaxBufferSize);
xnDumpWriteString(Dump(), "Allocated buffer %u with size %u\n", i, m_nMaxBufferSize);
// add it to free list
m_AllBuffers.AddLast(pBuffer);
m_FreeBuffers.AddLast(pBuffer);
}
return (XN_STATUS_OK);
}
XnStatus XnSensorAudioStream::ReallocBuffer()
{
XnStatus nRetVal = XN_STATUS_OK;
XnDevicePrivateData* pDevicePrivateData = m_Helper.GetPrivateData();
if (m_hSharedMemory == NULL)
{
// first time, create shared memory
// we allocate enough for 5 seconds of audio
XnUInt32 nSampleSize = 2 * 2; // 16-bit per channel (2 bytes) * max number of channels (2)
XnUInt32 nSamples = 48000 * 5; // max sample rate * number of seconds
XnUInt32 nMaxBufferSize = nSamples * nSampleSize;
// find min packet size (so we'll have max packet count)
XnUInt32 nMinPacketSize = XN_MIN(XN_SENSOR_PROTOCOL_AUDIO_PACKET_SIZE_BULK, XN_SENSOR_PROTOCOL_AUDIO_PACKET_SIZE_ISO);
XnUInt32 nMaxPacketCount = nMaxBufferSize / nMinPacketSize - 1;
XnUInt32 nSharedBufferSize =
sizeof(XnAudioSharedBuffer) + // header
sizeof(XnUInt64) * nMaxPacketCount + // packet timestamps
nMaxBufferSize;
// to make the name unique, we'll add process ID
XN_PROCESS_ID procID;
xnOSGetCurrentProcessID(&procID);
XnChar strSharedName[XN_DEVICE_MAX_STRING_LENGTH];
sprintf(strSharedName, "%u_%s_%s", procID, m_strDeviceName, GetName());
nRetVal = m_SharedBufferName.UnsafeUpdateValue(strSharedName);
XN_IS_STATUS_OK(nRetVal);
nRetVal = RequiredSizeProperty().UnsafeUpdateValue(nMaxBufferSize);
XN_IS_STATUS_OK(nRetVal);
nRetVal = xnOSCreateSharedMemory(strSharedName, nSharedBufferSize, XN_OS_FILE_READ | XN_OS_FILE_WRITE, &m_hSharedMemory);
XN_IS_STATUS_OK(nRetVal);
XnUChar* pAddress;
nRetVal = xnOSSharedMemoryGetAddress(m_hSharedMemory, (void**)&pAddress);
XN_IS_STATUS_OK(nRetVal);
m_pSharedHeader = (XnAudioSharedBuffer*)pAddress;
pDevicePrivateData->pAudioPacketsTimestamps = (XnUInt64*)(pAddress + sizeof(XnAudioSharedBuffer));
pDevicePrivateData->pAudioBuffer = (XN_AUDIO_TYPE*)(pAddress + sizeof(XnAudioSharedBuffer) + sizeof(XnUInt64) * nMaxPacketCount);
pDevicePrivateData->nAudioBufferSize = nMaxBufferSize;
m_pSharedHeader->nTimestampsListOffset = sizeof(XnAudioSharedBuffer);
m_pSharedHeader->nBufferOffset = pDevicePrivateData->pAudioBuffer - pAddress;
}
// calculate current packet size
pDevicePrivateData->nAudioPacketSize = m_nOrigAudioPacketSize;
if (m_Helper.GetFirmwareVersion() >= XN_SENSOR_FW_VER_5_2 && GetNumberOfChannels() == 1)
{
pDevicePrivateData->nAudioPacketSize /= 2;
}
pDevicePrivateData->nAudioBufferNumOfPackets = pDevicePrivateData->nAudioBufferSize / pDevicePrivateData->nAudioPacketSize;
pDevicePrivateData->nAudioBufferSize = pDevicePrivateData->nAudioBufferNumOfPackets * pDevicePrivateData->nAudioPacketSize;
m_pSharedHeader->nPacketCount = pDevicePrivateData->nAudioBufferNumOfPackets;
m_pSharedHeader->nPacketSize = pDevicePrivateData->nAudioPacketSize;
// set read and write indices
pDevicePrivateData->nAudioReadIndex = 0;
pDevicePrivateData->nAudioWriteIndex = 0;
return (XN_STATUS_OK);
}