javase/src/main/java/org/jcodec/api/awt/AWTFrameGrab.java
public static BufferedImage getFrame(SeekableDemuxerTrack vt, ContainerAdaptor decoder, int frameNumber)
            throws IOException, JCodecException {
        return ((AWTFrameGrab) new AWTFrameGrab(vt, decoder).seekToFramePrecise(frameNumber)).getFrame();
    }
public static BufferedImage getFrame(SeekableDemuxerTrack vt, ContainerAdaptor decoder, int frameNumber)
            throws IOException, JCodecException {
        return ((AWTFrameGrab) new AWTFrameGrab(vt, decoder).seekToFramePrecise(frameNumber)).getFrame();
    }
Get a specified frame by number from an already open demuxer track

@param vt
@param decoder
@param frameNumber
@return
@throws IOException
@throws JCodecException