org.freedesktop.gstreamer.ControlSource Maven / Gradle / Ivy

/* 
 * Copyright (c) 2019 Neil C Smith
 * 
 * This file is part of gstreamer-java.
 *
 * This code is free software: you can redistribute it and/or modify it under 
 * the terms of the GNU Lesser General Public License version 3 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT 
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License 
 * version 3 for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with this work.  If not, see .
 */
package org.freedesktop.gstreamer;

import org.freedesktop.gstreamer.lowlevel.GstControlSourcePtr;

import static org.freedesktop.gstreamer.lowlevel.GstControlSourceAPI.GSTCONTROLSOURCE_API;

/**
 * Base class for control source sources.
 * 
 * See upstream documentation at
 * https://gstreamer.freedesktop.org/data/doc/gstreamer/stable/gstreamer/html/GstControlSource.html
 * 

 */
public class ControlSource extends GstObject {
    
    public static final String GTYPE_NAME = "GstControlSource";

    private final Handle handle;

    protected ControlSource(Handle handle, boolean needRef) {
        super(handle, needRef);
        this.handle = handle;
    }

    ControlSource(Initializer init) {
        this(new Handle(
                init.ptr.as(GstControlSourcePtr.class, GstControlSourcePtr::new),
                init.ownsHandle),
                init.needRef);
    }

    /**
     * Gets the value for this ControlSource at a given timestamp.
     *
     * @param timestamp the time for which the value should be returned
     * @return value
     * @throws IllegalStateException if the value could not be calculated
     */
    public double getValue(long timestamp) {
        double[] out = new double[1];
        boolean ok = GSTCONTROLSOURCE_API.gst_control_source_get_value(handle.getPointer(), timestamp, out);
        if (ok) {
            return out[0];
        } else {
            throw new IllegalStateException();
        }
    }

    /**
     * Gets an array of values for for this ControlSource. Values that are
     * undefined contain NANs.
     *
     * @param timestamp the first timestamp
     * @param interval the time steps
     * @param values array to put control-values in
     * @return true if the values were successfully calculated
     */
    public boolean getValueArray(long timestamp, long interval, double[] values) {
        return GSTCONTROLSOURCE_API.gst_control_source_get_value_array(
                handle.getPointer(),
                timestamp,
                interval,
                values.length,
                values);
    }

    /**
     * A simple structure for saving a timestamp and a value.
     * 

     * Equivalent to GstTimedValue.
     * 
     * https://gstreamer.freedesktop.org/data/doc/gstreamer/stable/gstreamer/html/GstControlSource.html#GstTimedValue
     *
     */
    public static final class TimedValue {

        public final long timestamp;
        public final double value;

        /**
         * Create a TimedValue wrapping the timestamp (see {@link ClockTime})
         * and corresponding value.
         *
         * @param timestamp the timestamp (GstClockTime) of the value change
         * @param value the corresponding value
         */
        public TimedValue(long timestamp, double value) {
            this.timestamp = timestamp;
            this.value = value;
        }

        @Override
        public int hashCode() {
            int hash = 7;
            hash = 37 * hash + (int) (this.timestamp ^ (this.timestamp >>> 32));
            hash = 37 * hash + (int) (Double.doubleToLongBits(this.value) ^ (Double.doubleToLongBits(this.value) >>> 32));
            return hash;
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj == null) {
                return false;
            }
            if (getClass() != obj.getClass()) {
                return false;
            }
            final TimedValue other = (TimedValue) obj;
            if (this.timestamp != other.timestamp) {
                return false;
            }
            if (Double.doubleToLongBits(this.value) != Double.doubleToLongBits(other.value)) {
                return false;
            }
            return true;
        }

        @Override
        public String toString() {
            return "TimedValue{" + "timestamp=" + timestamp + ", value=" + value + '}';
        }

    }

    protected static class Handle extends GstObject.Handle {

        public Handle(GstControlSourcePtr ptr, boolean ownsHandle) {
            super(ptr, ownsHandle);
        }

        @Override
        protected GstControlSourcePtr getPointer() {
            return (GstControlSourcePtr) super.getPointer();
        }

    }

}