/** {@inheritDoc} */
public long getLocalTime(long ssrc, long rtp0) {
// don't use getSSRCDesc, because we don't want to create an instance
SSRCDesc ssrcDesc = ssrcs.get(ssrc);
if (ssrcDesc == null) {
return -1;
}
// get all required times
long clockRate; // the clock rate for the RTP clock for the given SSRC
long rtp1; // some time X in the RTP clock for the given SSRC
double ntp1; // the same time X in the source's wallclock
String endpointId;
synchronized (ssrcDesc) {
clockRate = ssrcDesc.clockRate;
rtp1 = ssrcDesc.rtpTime;
ntp1 = ssrcDesc.ntpTime;
endpointId = ssrcDesc.endpointId;
}
// if something is missing, we can't calculate the time
if (clockRate == -1 || rtp1 == -1 || ntp1 == -1.0 || endpointId == null) {
return -1;
}
Endpoint endpoint = endpoints.get(ssrcDesc.endpointId);
if (endpoint == null) {
return -1;
}
double ntp2; // some time Y in the source's wallclock (same clock as for ntp1)
long local2; // the same time Y in the local clock
synchronized (endpoint) {
ntp2 = endpoint.ntpTime;
local2 = endpoint.localTime;
}
if (ntp2 == -1.0 || local2 == -1) {
return -1;
}
// crunch the numbers. we're looking for 'local0',
// the local time corresponding to 'rtp0'
long local0;
double diff1S = ntp1 - ntp2;
double diff2S = ((double) TimeUtils.rtpDiff(rtp0, rtp1)) / clockRate;
long diffMs = Math.round((diff1S + diff2S) * 1000);
local0 = local2 + diffMs;
return local0;
}
/**
* Returns a <tt>SimulcastLayer</tt> that is the closest match to the target order, or null if
* simulcast hasn't been configured for this receiver.
*
* @param targetOrder the simulcast layer target order.
* @return a <tt>SimulcastLayer</tt> that is the closest match to the target order, or null.
*/
public SimulcastLayer getSimulcastLayer(int targetOrder) {
SimulcastLayer[] layers = getSimulcastLayers();
if (layers == null || layers.length == 0) {
return null;
}
// Iterate through the simulcast layers that we own and return the one
// that matches best the targetOrder parameter.
SimulcastLayer next = layers[0];
for (int i = 1; i < Math.min(targetOrder + 1, layers.length); i++) {
if (!layers[i].isStreaming()) {
break;
}
next = layers[i];
}
return next;
}
/**
* Opens a connection to the media source of the associated <tt>DataSource</tt>.
*
* @throws IOException if anything goes wrong while opening a connection to the media source of
* the associated <tt>DataSource</tt>
*/
public synchronized void connect() throws IOException {
javax.media.format.AudioFormat af = (javax.media.format.AudioFormat) getFormat();
int channels = af.getChannels();
int channelConfig;
switch (channels) {
case Format.NOT_SPECIFIED:
case 1:
channelConfig = AudioFormat.CHANNEL_IN_MONO;
break;
case 2:
channelConfig = AudioFormat.CHANNEL_IN_STEREO;
break;
default:
throw new IOException("channels");
}
int sampleSizeInBits = af.getSampleSizeInBits();
int audioFormat;
switch (sampleSizeInBits) {
case 8:
audioFormat = AudioFormat.ENCODING_PCM_8BIT;
break;
case 16:
audioFormat = AudioFormat.ENCODING_PCM_16BIT;
break;
default:
throw new IOException("sampleSizeInBits");
}
double sampleRate = af.getSampleRate();
length =
(int)
Math.round(
20 /* milliseconds */ * (sampleRate / 1000) * channels * (sampleSizeInBits / 8));
/*
* Apart from the thread in which #read(Buffer) is executed, use the
* thread priority for the thread which will create the AudioRecord.
*/
setThreadPriority();
try {
int minBufferSize =
AudioRecord.getMinBufferSize((int) sampleRate, channelConfig, audioFormat);
audioRecord =
new AudioRecord(
MediaRecorder.AudioSource.DEFAULT,
(int) sampleRate,
channelConfig,
audioFormat,
Math.max(length, minBufferSize));
// tries to configure audio effects if available
configureEffects();
} catch (IllegalArgumentException iae) {
IOException ioe = new IOException();
ioe.initCause(iae);
throw ioe;
}
setThreadPriority = true;
}
/**
* Inspect an <tt>RTCPCompoundPacket</tt> and build-up the state for future estimations.
*
* @param pkt
*/
public void apply(RTCPCompoundPacket pkt) {
if (pkt == null || pkt.packets == null || pkt.packets.length == 0) {
return;
}
for (RTCPPacket rtcpPacket : pkt.packets) {
switch (rtcpPacket.type) {
case RTCPPacket.SR:
RTCPSRPacket srPacket = (RTCPSRPacket) rtcpPacket;
// The media sender SSRC.
int ssrc = srPacket.ssrc;
// Convert 64-bit NTP timestamp to Java standard time.
// Note that java time (milliseconds) by definition has
// less precision then NTP time (picoseconds) so
// converting NTP timestamp to java time and back to NTP
// timestamp loses precision. For example, Tue, Dec 17
// 2002 09:07:24.810 EST is represented by a single
// Java-based time value of f22cd1fc8a, but its NTP
// equivalent are all values ranging from
// c1a9ae1c.cf5c28f5 to c1a9ae1c.cf9db22c.
// Use round-off on fractional part to preserve going to
// lower precision
long fraction = Math.round(1000D * srPacket.ntptimestamplsw / 0x100000000L);
/*
* If the most significant bit (MSB) on the seconds
* field is set we use a different time base. The
* following text is a quote from RFC-2030 (SNTP v4):
*
* If bit 0 is set, the UTC time is in the range
* 1968-2036 and UTC time is reckoned from 0h 0m 0s UTC
* on 1 January 1900. If bit 0 is not set, the time is
* in the range 2036-2104 and UTC time is reckoned from
* 6h 28m 16s UTC on 7 February 2036.
*/
long msb = srPacket.ntptimestampmsw & 0x80000000L;
long remoteTime =
(msb == 0)
// use base: 7-Feb-2036 @ 06:28:16 UTC
? msb0baseTime + (srPacket.ntptimestampmsw * 1000) + fraction
// use base: 1-Jan-1900 @ 01:00:00 UTC
: msb1baseTime + (srPacket.ntptimestampmsw * 1000) + fraction;
// Estimate the clock rate of the sender.
int frequencyHz = -1;
if (receivedClocks.containsKey(ssrc)) {
// Calculate the clock rate.
ReceivedRemoteClock oldStats = receivedClocks.get(ssrc);
RemoteClock oldRemoteClock = oldStats.getRemoteClock();
frequencyHz =
Math.round(
(float)
(((int) srPacket.rtptimestamp - oldRemoteClock.getRtpTimestamp())
& 0xffffffffl)
/ (remoteTime - oldRemoteClock.getRemoteTime()));
}
// Replace whatever was in there before.
receivedClocks.put(
ssrc,
new ReceivedRemoteClock(
ssrc, remoteTime, (int) srPacket.rtptimestamp, frequencyHz));
break;
case RTCPPacket.SDES:
break;
}
}
}