Google vs. Apple(businessweek.com)

   // GetMediaSampleDescription takes a SampleDescriptionHandle, but apparently
   // if the media is a sound (which presumably we know it is) then it will treat
   // it as a SoundDescriptionHandle (which in addition to the format of single
   // samples, also tells you sample rate, number of channels, etc.)
   // Pretty messed up interface, if you ask me.
   SoundDescriptionHandle soundDescription = (SoundDescriptionHandle)NewHandle(0);
   GetMediaSampleDescription(mMedia, 1, (SampleDescriptionHandle)soundDescription);

   // If this is a compressed format, it may have out-of-stream compression
   // parameters that need to be passed to the sound converter.  We retrieve
   // these in the form of an audio atom.  To do this, however we have to
   // get the data by way of a handle, then copy it manually from the handle to
   // the atom.  These interfaces get worse all the time!
   Handle decompressionParamsHandle = NewHandle(0);
   AudioFormatAtomPtr decompressionParamsAtom = NULL;
   err = GetSoundDescriptionExtension(soundDescription, &decompressionParamsHandle,
                                      siDecompressionParams);
   if(err == noErr)
   {
      // this stream has decompression parameters.  copy from the handle to the atom.
      int paramsSize = GetHandleSize(decompressionParamsHandle);
      HLock(decompressionParamsHandle);
      decompressionParamsAtom = (AudioFormatAtomPtr)NewPtr(paramsSize);
      BlockMoveData(*decompressionParamsHandle, decompressionParamsAtom, paramsSize);
      HUnlock(decompressionParamsHandle);
   }