/// <summary>
/// Callback function for the outputstream.
/// </summary>
/// <param name="streamHandle">Bass stream handle that requests sample data.</param>
/// <param name="buffer">Buffer to write the sampledata to.</param>
/// <param name="requestedBytes">Requested number of bytes.</param>
/// <param name="userData"></param>
/// <returns>Number of bytes read.</returns>
private int OutputStreamWriteProc(int streamHandle, IntPtr buffer, int requestedBytes, IntPtr userData)
{
IInputSource inputSource;
lock (_syncObj)
{
if (_state == SessionState.Reset)
{
return(0);
}
inputSource = _currentInputSource;
if (inputSource == null)
{
_state = SessionState.Ended;
return((int)BASSStreamProc.BASS_STREAMPROC_END);
}
}
try
{
BassStream stream = inputSource.OutputStream;
int read = stream.Read(buffer, requestedBytes);
bool doCheckNextInputSource = false;
lock (_syncObj)
if (!_isAwaitingNextInputSource && stream.GetPosition() > stream.Length.Subtract(REQUEST_NEXT_ITEM_THRESHOLD))
{ // Near end of the stream - make sure that next input source is available
_isAwaitingNextInputSource = true;
doCheckNextInputSource = true;
}
if (doCheckNextInputSource)
{
_playbackProcessor.CheckInputSourceAvailable();
}
if (read > 0)
{
// Normal case, we have finished
return(read);
}
// Old buffer ran out of samples - either we can get another valid input source below or we are finished. End wait state.
_isAwaitingNextInputSource = false;
// Nothing could be read from old input source. Second try: Next input source.
IInputSource newInputSource = _playbackProcessor.PeekNextInputSource();
// Special treatment for CD drives: If the new input source is from the same audio CD drive, we must take the stream over
BassCDTrackInputSource bcdtisOld = inputSource as BassCDTrackInputSource;
BassCDTrackInputSource bcdtisNew = newInputSource as BassCDTrackInputSource;
if (bcdtisOld != null && bcdtisNew != null)
{
if (bcdtisOld.SwitchTo(bcdtisNew))
{
_playbackProcessor.ClearNextInputSource();
return(OutputStreamWriteProc(streamHandle, buffer, requestedBytes, userData));
}
}
lock (_syncObj)
{
_currentInputSource = null;
_controller.ScheduleDisposeObject_Async(inputSource);
if (newInputSource == null)
{
_state = SessionState.Ended;
return((int)BASSStreamProc.BASS_STREAMPROC_END);
}
}
if (!MatchesInputSource(newInputSource))
{ // The next available input source is not compatible, so end our stream. The playback processor will start a new playback session later.
lock (_syncObj)
_state = SessionState.Ended;
return((int)BASSStreamProc.BASS_STREAMPROC_END);
}
_playbackProcessor.ClearNextInputSource(); // Should be the contents of newInputSource
lock (_syncObj)
{
_currentInputSource = newInputSource;
_state = SessionState.Playing;
}
// Next try
return(OutputStreamWriteProc(streamHandle, buffer, requestedBytes, userData));
}
catch (Exception)
{
// We might come here due to a race condition. To avoid that, we would have to employ a new manual locking mechanism
// to avoid that during the execution of this method, no methods are called from outside which change our
// streams/partner instances.
return(0);
}
}
/// <summary>
/// Moves to the next available input source.
/// </summary>
/// <remarks>
/// This method blocks the calling thread as long as the switching to the new input source lasts. This includes
/// the crossfading duration (if crossfading is done) or the fading out (if no crossfading is done).
/// </remarks>
protected void MoveToNextInputSource_Sync()
{
// TODO: Insert gap between tracks if we are in playback mode Normal
IInputSource inputSource = PeekNextInputSource();
if (_playbackSession != null)
{
BassCDTrackInputSource bcdtisNew = inputSource as BassCDTrackInputSource;
IInputSource currentInputSource = _playbackSession.CurrentInputSource;
BassCDTrackInputSource bcdtisOld = currentInputSource as BassCDTrackInputSource;
if (bcdtisOld != null && bcdtisNew != null)
{
// Special treatment for CD drives: If the new input source is from the same audio CD drive, we must take the stream over
if (bcdtisOld.SwitchTo(bcdtisNew))
{
_playbackSession.IsAwaitingNextInputSource = false;
ClearNextInputSource();
return;
}
}
// TODO: Trigger crossfading if CF is configured
_playbackSession.End(_internalState == InternalPlaybackState.Playing); // Only wait for fade out when we are playing
}
_internalState = InternalPlaybackState.Playing;
if (inputSource == null)
{
Log.Debug("No more input sources available.");
}
else
{
Log.Debug("Playing next input source '{0}'", inputSource);
}
if (_playbackSession != null)
{
if (_playbackSession.InitializeWithNewInputSource(inputSource))
{
_playbackSession.Play();
ClearNextInputSource();
return;
}
_playbackSession.Dispose();
_playbackSession = null;
}
if (inputSource == null)
{
Ended();
return;
}
_playbackSession = PlaybackSession.Create(_controller);
if (_playbackSession == null)
{
_internalState = InternalPlaybackState.Stopped;
return;
}
_playbackSession.Play();
_internalState = InternalPlaybackState.Playing;
_controller.StateReady();
}