Xtykutl

I am looking at the JMF code source, written out as an answer on this thread by user Mavie. As I try to trace the code, from the function doIt --> ImageDataSource --> ImageSourceStream, I'm not too clear how the program reads the list of image files from the vector.

As far as I know, this part of the code read(Buffer buf) reads the image data file, but this function does not seem to be called by the processor from within the code itself.

I have managed to get the code running perfectly fine, but do not understand the logical flow. How/Where does the processor call this function to read and generate the video?

read(Buffer buf) - part of the entire source code

/**

 * This is called from the Processor to read a frame worth of video

 * data.

 */

 public void read(Buffer buf) throws IOException {



        // Check if we've finished all the frames.

        if (nextImage >= images.size()) {

            // We are done. Set EndOfMedia.

            //System.err.println("Done reading all images.");

            buf.setEOM(true);

            buf.setOffset(0);

            buf.setLength(0);

            ended = true;

            return;

        }



        String imageFile = (String) images.elementAt(nextImage);

        nextImage++;



        //System.err.println("  - reading image file: " + imageFile);



        // Open a random access file for the next image.

        RandomAccessFile raFile;

        raFile = new RandomAccessFile(imageFile, "r");



        byte data = null;



        // Check the input buffer type & size.



        if (buf.getData() instanceof byte)

            data = (byte) buf.getData();



        // Check to see the given buffer is big enough for the frame.

        if (data == null || data.length < raFile.length()) {

            data = new byte[(int) raFile.length()];

            buf.setData(data);

        }



        // Read the entire JPEG image from the file.

        raFile.readFully(data, 0, (int) raFile.length());



        //System.err.println("    read " + raFile.length() + " bytes.");



        buf.setOffset(0);

        buf.setLength((int) raFile.length());

        buf.setFormat(format);

        buf.setFlags(buf.getFlags() | buf.FLAG_KEY_FRAME);



        // Close the random access file.

        raFile.close();

    }