To access the AMFPacket timecodes, there are a few different methods that you can use, depending on what you want.
If you just want the latest timecode in the stream, you can call stream.getMaxTimecode(); or stream.getAudioTC(); or stream.getVideoTC(); for the audio & video respectively.
If you want to get the latest AMF Packets, you can call stream.getLastPacket(); or stream.getLastKeyFrame();. To get a list of the available AMF packets on the stream, you can call stream.getPlayPackets();. This list is constantly updating so you will need to keep track of the packet sequence numbers. With the AMF Packets, you can call packet.getAbsTimecode(); to get the packet timecode. There is also a *getTimecode();*method which is the delta offset to the previous packet of the same type.
These methods are available on all published streams. To gain access to the published stream, you can use:
IMediaStream stream = appInstance.getStreams().getStream(streamName);if(stream != null){ ...}