/*
* Envelope.java
* Transform
*
* Copyright (c) 2001-2010 Flagstone Software Ltd. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Flagstone Software Ltd. nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package com.flagstone.transform.sound;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import com.flagstone.transform.Constants;
import com.flagstone.transform.coder.Coder;
import com.flagstone.transform.coder.Context;
import com.flagstone.transform.coder.Copyable;
import com.flagstone.transform.coder.SWFDecoder;
import com.flagstone.transform.coder.SWFEncodeable;
import com.flagstone.transform.coder.SWFEncoder;
import com.flagstone.transform.exception.IllegalArgumentRangeException;
/**
* Envelope is a container class for Level objects that describe how the volume
* of a sound changes over time.
*/
public final class Envelope implements SWFEncodeable, Copyable<Envelope> {
/**
* Level describes the sound levels for stereo sound.
*
* <p>
* Each Level object contains a sample number in the audio <b>when it is
* played</b> where the envelope will be applied along with the sound levels
* for the left and right channels.
* </p>
*
* <p>
* The Flash Player plays sounds at a fixed rate of 44.1KHz, therefore
* sounds sampled at a lower frequency are interpolated with each sample
* repeated to generated the 44.1Khz playback rate. For example each sample
* in a sound sampled at 22KHz is played twice to generated the 44.1Khz
* playback rate.
* </p>
*
* <p>
* The Level defines the sample number (and hence the time) in the
* playback data stream where the level information applies and <b>not</b>
* the sample number in the original sound data. For example to set the
* level 0.1 seconds into a sound that plays for 1 second the value for the
* mark attribute in the envelope object would be 44100 * 0.1/1.0 = 4410.
* </p>
*
* @see SoundInfo
*/
public static final class Level implements SWFEncodeable {
/** Format string used in toString() method. */
private static final String FORMAT = "Envelope: { mark=%d; left=%d;"
+ " right=%d}";
/** The sample number (at 44KHz) where the levels apply. */
private final transient int mark;
/** The sound level for the left channel. */
private final transient int left;
/** The sound level for the right channel. */
private final transient int right;
/**
* Creates and initialises a sound Level object using values encoded
* in the Flash binary format.
*
* @param coder
* an SWFDecoder object that contains the encoded Flash data.
*
* @throws IOException
* if an error occurs while decoding the data.
*/
public Level(final SWFDecoder coder) throws IOException {
mark = coder.readInt();
left = coder.readUnsignedShort();
right = coder.readUnsignedShort();
}
/**
* Creates a envelope specifying the mark, left and right sound levels.
*
* @param markValue
* the sample number in the 44.1KHz playback data stream
* where the levels for the channels is applied.
* @param leftValue
* the level for the left sound channel, in the range
* 0..65535.
* @param rightValue
* the level for the right sound channel, in the range
* 0..65535.
*/
public Level(final int markValue, final int leftValue,
final int rightValue) {
mark = markValue;
if ((leftValue < 0) || (leftValue > Coder.USHORT_MAX)) {
throw new IllegalArgumentRangeException(0,
Coder.USHORT_MAX, leftValue);
}
left = leftValue;
if ((rightValue < 0) || (rightValue > Coder.USHORT_MAX)) {
throw new IllegalArgumentRangeException(0,
Coder.USHORT_MAX, rightValue);
}
right = rightValue;
}
/**
* Get the sample number in the 44.1KHz playback data stream where
* the level information is applied.
*
* @return the sample number where the sound levels will be applied.
*/
public int getMark() {
return mark;
}
/**
* Get the level of the sound played in the left channel.
*
* @return the sound level for the left channel.
*/
public int getLeft() {
return left;
}
/**
* Get the level of the sound played in the right channel.
*
* @return the sound level for the right channel.
*/
public int getRight() {
return right;
}
@Override
public String toString() {
return String.format(FORMAT, mark, left, right);
}
@Override
public boolean equals(final Object object) {
boolean result;
Level level;
if (object == null) {
result = false;
} else if (object == this) {
result = true;
} else if (object instanceof Level) {
level = (Level) object;
result = (mark == level.mark) && (left == level.left)
&& (right == level.right);
} else {
result = false;
}
return result;
}
@Override
public int hashCode() {
return ((mark * Constants.PRIME) + left) * Constants.PRIME + right;
}
/** {@inheritDoc} */
@Override
public int prepareToEncode(final Context context) {
// CHECKSTYLE IGNORE MagciNumberCheck FOR NEXT 1 LINES
return 8;
}
/** {@inheritDoc} */
@Override
public void encode(final SWFEncoder coder, final Context context)
throws IOException {
coder.writeInt(mark);
coder.writeShort(left);
coder.writeShort(right);
}
}
/** List of sound levels that define the envelope. */
private List<Level> levels;
/** Number of levels in list. */
private transient int count;
/**
* Creates and initialises an Envelope object using values encoded
* in the Flash binary format.
*
* @param coder
* an SWFDecoder object that contains the encoded Flash data.
*
* @throws IOException
* if an error occurs while decoding the data.
*/
public Envelope(final SWFDecoder coder) throws IOException {
count = coder.readByte();
levels = new ArrayList<Level>(count);
for (int i = 0; i < count; i++) {
levels.add(new Level(coder));
}
}
/**
* Creates and initialises an Envelope object using the values copied
* from another Envelope object.
*
* @param object
* an Envelope object from which the values will be
* copied.
*/
public Envelope(final Envelope object) {
levels = new ArrayList<Level>(object.levels);
}
/**
* Add a Envelope object to the list of envelope objects.
*
* @param level
* a SoundLevel object. Must not be null.
* @return this object.
*/
public Envelope add(final Level level) {
if (level == null) {
throw new IllegalArgumentException();
}
levels.add(level);
return this;
}
/**
* Get the list of Levels that control the volume of the sound.
*
* @return the Levels that define the envelope.
*/
public List<Level> getLevels() {
return levels;
}
/**
* Sets the list of Levels that define the levels at which a
* sound is played over the duration of the sound. May be set to null if no
* envelope is defined.
*
* @param list
* a list of Envelope objects. Must not be null.
*/
public void setLevels(final List<Level> list) {
if (list == null) {
throw new IllegalArgumentException();
}
levels = list;
}
/** {@inheritDoc} */
@Override
public Envelope copy() {
return new Envelope(this);
}
@Override
public String toString() {
return levels.toString();
}
/** {@inheritDoc} */
@Override
public int prepareToEncode(final Context context) {
// CHECKSTYLE IGNORE MagicNumberCheck FOR NEXT 2 LINES
count = levels.size();
return 1 + (count << 3);
}
/** {@inheritDoc} */
@Override
public void encode(final SWFEncoder coder, final Context context)
throws IOException {
coder.writeByte(count);
for (final Level level : levels) {
level.encode(coder, context);
}
}
}