/*
* Copyright (c) 2008 Wayne Meissner
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wim.taymans@chello.be>
* 2005 Wim Taymans <wim@fluendo.com>
*
* 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 <http://www.gnu.org/licenses/>.
*/
package org.gstreamer.event;
import org.gstreamer.Event;
import org.gstreamer.Format;
import org.gstreamer.SeekType;
import org.gstreamer.lowlevel.GstNative;
import com.sun.jna.Pointer;
/**
* A request for a new playback position and rate.
* <p>
* The seek event configures playback of the pipeline between <tt>start</tt> to <tt>stop</tt>
* at the speed given in <tt>rate</tt>, also called a playback segment.
* <p>
* The <tt>start</tt> and <tt>stop</tt> values are expressed in <tt>format</tt>.
* <p>
* A <tt>rate</tt> of 1.0 means normal playback rate, 2.0 means double speed.
* Negative values means backwards playback. A value of 0.0 for the
* rate is not allowed and should be accomplished instead by PAUSING the
* pipeline.
* <p>
* A pipeline has a default playback segment configured with a start
* position of 0, a stop position of -1 and a rate of 1.0. The currently
* configured playback segment can be queried with #GST_QUERY_SEGMENT.
* <p>
* <ttstartType</tt> and <tt>stopType</tt> specify how to adjust the currently configured
* start and stop fields in <tt>segment</tt>. Adjustments can be made relative or
* absolute to the last configured values. A type of {@link SeekType#NONE} means
* that the position should not be updated.
* <p>
* When the rate is positive and <tt>start</tt> has been updated, playback will start
* from the newly configured start position.
* <p>
* For negative rates, playback will start from the newly configured <tt>stop<tt>
* position (if any). If the stop position if updated, it must be different from
* -1 for negative rates.
* <p>
* It is not possible to seek relative to the current playback position, to do
* this, PAUSE the pipeline, query the current playback position with
* {@link org.gstreamer.Pipeline#queryPosition getPosition} and update the playback segment
* current position with a {@link SeekType#SET} to the desired position.
*/
public class SeekEvent extends Event {
private static interface API extends com.sun.jna.Library {
Pointer ptr_gst_event_new_seek(double rate, Format format, int flags,
SeekType start_type, long start, SeekType stop_type, long stop);
void gst_event_parse_seek(Event event, double[] rate, Format[] format,
int[] flags, SeekType[] start_type, long[] start,
SeekType[] stop_type, long[] stop);
}
private static final API gst = GstNative.load(API.class);
/**
* This constructor is for internal use only.
* @param init initialization data.
*/
public SeekEvent(Initializer init) {
super(init);
}
/**
* Creates a new seek event.
*
* @param rate the new playback rate
* @param format the format of the seek values
* @param flags the optional seek flags
* @param startType the type and flags for the new start position
* @param start the value of the new start position
* @param stopType the type and flags for the new stop position
* @param stop the value of the new stop position
*/
public SeekEvent(double rate, Format format, int flags,
SeekType startType, long start, SeekType stopType, long stop) {
super(initializer(gst.ptr_gst_event_new_seek(sanitizeRate(rate), format,
flags, startType, start, stopType, stop)));
}
private static double sanitizeRate(double rate) {
if (rate == 0d) {
throw new IllegalArgumentException("Cannot have rate == 0.0");
}
return rate;
}
/**
* Gets the playback rate.
*
* A <tt>rate</tt> of 1.0 means normal playback rate, 2.0 means double speed.
* Negative values means backwards playback. A value of 0.0 for the
* rate is not allowed and should be accomplished instead by PAUSING the
* pipeline.
*
* @return the playback rate.
*/
public double getRate() {
double[] rate = { 0d };
gst.gst_event_parse_seek(this, rate, null, null, null, null, null, null);
return rate[0];
}
/**
* Gets the {@link Format} of the start and stop seek values.
*
* @return the format.
*/
public Format getFormat() {
Format[] format = new Format[1];
gst.gst_event_parse_seek(this, null, format, null, null, null, null, null);
return format[0];
}
/**
* Gets the {@link org.gstreamer.SeekFlags} of this seek event.
*
* @return the seek flags.
*/
public int getFlags() {
int[] flags = { 0 };
gst.gst_event_parse_seek(this, null, null, flags, null, null, null, null);
return flags[0];
}
/**
* Gets the SeekType of the start value.
*
* @return the SeekType.
*/
public SeekType getStartType() {
SeekType[] type = new SeekType[1];
gst.gst_event_parse_seek(this, null, null, null, type, null, null, null);
return type[0];
}
/**
* Gets the start of the seek segment.
*
* @return the start of the seek.
*/
public long getStart() {
long[] value = { 0 };
gst.gst_event_parse_seek(this, null, null, null, null, value, null, null);
return value[0];
}
/**
* Gets the SeekType of the start value.
*
* @return the SeekType.
*/
public SeekType getStopType() {
SeekType[] type = new SeekType[1];
gst.gst_event_parse_seek(this, null, null, null, null, null, type, null);
return type[0];
}
/**
* Gets the stop position of the seek.
*
* @return the stop position.
*/
public long getStop() {
long[] value = { 0 };
gst.gst_event_parse_seek(this, null, null, null, null, null, null, value);
return value[0];
}
}