Audio position-

Question

I am using Audio Queues for playback and recording. For the playback, I need sometimes to start at a specific position, or to jump at a specific position.
Is there a way to do that?
Also, is there a way to retrieve the current position where the player is in the file.
Thanks

Answer 1

In case anyone is still looking for this information, I modified the SpeakHere Application to do both of these functions. Here are the I added to the AudioPlayer:
- (void) setPlayPosition:(Float64) seconds startPlaying:(BOOL)startPlaying {
AudioQueuePause (self.queueObject);
AudioQueueReset (self.queueObject);
startingPacketNumber = seconds * audioFormat.mSampleRate / audioFormat.mFramesPerPacket;
[self setupPlaybackAudioQueueObject];
if (startPlaying) AudioQueueStart (self.queueObject, NULL);
- (UInt32) estimateTimeLapsed {
UInt32 currentTime = (startingPacketNumber - (numPacketsToRead * kNumberAudioDataBuffers )) * audioFormat.mFramesPerPacket / audioFormat.mSampleRate;
return currentTime;
It's possible to get a TimeStamp from the buffer, but it get's messsed up after changing the play position. I haven't tried managing this with a Timeline.
The estimateTimeLapsed method above calculates the time based on the current startingPacketNumber. StartingPacketNumber is the next packet to be read by one of the [3] buffers rather than the one playing, so it counts back to the one playing assuming all the buffers are active. It seems like a silly way to do it, but it's giving me all the accuracy I need right now.
Message was edited by: shindigg