Method writeSamples

Transceiver52M/USRPDevice.cpp:453–506

}

int USRPDevice::writeSamples(short *buf, int len, bool *underrun, 
			     unsigned long long timestamp,
			     bool isControl) 
{
  writeLock.lock();

#ifndef SWLOOPBACK 
  if (!m_uTx) return 0;
 
  static uint32_t outData[128*20];
 
  for (int i = 0; i < len*2; i++) {
	buf[i] = host_to_usrp_short(buf[i]);
  }

  int numWritten = 0;
  unsigned isStart = 1;
  unsigned RSSI = 0;
  unsigned CHAN = (isControl) ? 0x01f : 0x00;
  len = len*2*sizeof(short);
  int numPkts = (int) ceil((float)len/(float)504);
  unsigned isEnd = (numPkts < 2);
  uint32_t *outPkt = outData;
  int pktNum = 0;
  while (numWritten < len) {
    // pkt is pointer to start of a USB packet
    uint32_t *pkt = outPkt + pktNum*128;
    isEnd = (len - numWritten <= 504);
    unsigned payloadLen = ((len - numWritten) < 504) ? (len-numWritten) : 504;
    pkt[0] = (isStart << 12 | isEnd << 11 | (RSSI & 0x3f) << 5 | CHAN) << 16 | payloadLen;
    pkt[1] = timestamp & 0x0ffffffffll;
    memcpy(pkt+2,buf+(numWritten/sizeof(short)),payloadLen);
    numWritten += payloadLen;
    timestamp += payloadLen/2/sizeof(short);
    isStart = 0;
    pkt[0] = host_to_usrp_u32(pkt[0]);
    pkt[1] = host_to_usrp_u32(pkt[1]);
    pktNum++;
  }
  m_uTx->write((const void*) outPkt,sizeof(uint32_t)*128*numPkts,NULL);

  samplesWritten += len/2/sizeof(short);
  writeLock.unlock();

  return len/2/sizeof(short);
#else
  int retVal = len;
  memcpy(loopbackBuffer+loopbackBufferSize,buf,sizeof(short)*2*len);
  samplesWritten += retVal;
  loopbackBufferSize += retVal*2;
   
  return retVal;
#endif
}

bool USRPDevice::updateAlignment(TIMESTAMP timestamp) 
{