JMF and audio streams

Question

Hi all,
I am writing an application that reads an audio stream and performs some analysis on the audio samples (e.g. detection of dtmf tones). I'd like to be able to write some code that works both on streams from files and from RTP connections (in order to easily write test classes). I made a little test program that reads a wav file with javasound and does some audio analysis.
public static void main(String[] args)
   AudioInputStream sound = AudioSystem.getAudioInputStream(new File(args[0]));
   int length = (int) sound.getFrameLength();
   for(int i=0; i<length; i++)
      byte[] sample = new byte[2];
      int res = in.read(sample, 0, sample.length);
      if(res != sample.length)
         throw new RuntimeException(
            "Couldn't read a 2 bytes sample from audio stream.");
      if(!in.getFormat().isBigEndian())
         byte tmp = sample[0];
         sample[0] = sample[1];
         sample[1] = tmp;
      DataInputStream ds = new DataInputStream(
         new ByteArrayInputStream(sample));
      goertzel(ds.readShort());
}Now, I tried to do the same using JMF but I failed. More specific in JMF:
1) How can I get informations about the stream I'm reading? (e.g. all infos I can get from AudioInputStream's getFormat() method)
2) Is there a way to get a stream from a DataSource and determine at runtime if the stream is in a particular format I'm expecting, WITHOUT bothering if it is coming form RTP, audio file or something else?
3) Eventually, Is it hard to use the stream I'm reading to create a new DataSource that some other component will use?

Answer 1

Sorry but.. I don't know which is the appropriate subclass: I can't find it. I guess you missed "instanceof" in Java 101, eh?
Moreover I'd like to find a class that is not something like "RTPStream" or "AudioFileInputStream" but something representing just the audio stream itself.There are ways you can get access to the raw data as it flows through the system, but as far as I know, there's no way of gaining random access to the audio stream itself...
Note that a solution could be to use javasound AudioInputStream class and a simple java rtp library. I could implement my Audio analysis methods in order to work on "abstract streams" (given a particular audio format), then write a test class that work with audio files and a real application that gets input streams from RTP connections.
I just want to know whether JMF allows me do do that or not?It'd be relatively simple to use JMF to receive an RTP stream and "export" it to JavaSound... you'd just need to write a custom DataSink.