JMF with Fobs4jmf: Problem getting supported formats

Question

I'm trying to use JMF with fobs4jmf to try stitching together video files into a single file. Fortunately, I found a sample program to do just that in the SDN website (http://java.sun.com/javase/technologies/desktop/media/jmf/2.1.1/solutions/Concat.html).
I copied and pasted the Concat.java class in a new Eclipse Java class, set up the classpaths, and tested it. (I've gone through the pain of setting up and resetting classpaths so that the JMF diagnostics is able to detect the correct JMF installation in my machine).
However, in the tryMatch method of Concat.java, I am getting an empty array of Format objects, represented by the "supported" variable, during a call to the following:
{color:#0000ff}TrackControl tc = pInfo[0].tracksByType[type][trackID].tc;
Format origFmt = tc.getFormat();
Format newFmt, oldFmt;
Format supported[] = tc.getSupportedFormats();
for (int i = 0; i < supported.length; i++) {
if (supported[i] instanceof AudioFormat) {
// If it's not the original format, then for audio, we'll
// only do linear since it's more accurate to compute the
// audio times.
if (!supported.matches(tc.getFormat()) &&
!supported[i].getEncoding().equalsIgnoreCase(AudioFormat.LINEAR))
continue;
{color:#000000}Here's my problem: While on debug mode, I see that the "supported" variable shows an empty array, when I look deeper in the TrackControl tc variable and look the its supportedFormats instance variable, I can see that it has a value. For my testing, I used a .mov file and the supportedFormats variable contains an {color:#0000ff}AudioFormat{color} with the value {color:#0000ff}mp4a, 32000.0 Hz, 16-bit, Stereo, BigEndian, Signed, FrameSize=32 bits{color}.
{color}
{color:#000000}I can't get past through this hurdle for now. Why am I getting an empty array of Format objects when the TrackControl tc variable actually contains value in its supportedFormats property?
I'd appreciate any help on this matter.
Anthony
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Answer 1

I again don't have my code in front of me, but I did take a look at the sample code my code is based on...
Format format = tracks.getFormat();
if (tracks[i].isEnabled()) {
supported = tracks[i].getSupportedFormats();
Just a shot in the dark, but perhaps getSupportedFormats returns the empty set when the TrackControl object is disabled?
Try enabling the TrackControl before you try to get its supported formats, and see if that changes the behavior in any sort of meaningful way?