fssoundstreamhead.java

利用opensource的开源jar实现生成flash文件

/*
 * FSSoundStreamHead.java
 * Transform
 * 
 * Copyright (c) 2001-2006 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, 
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 * 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;

/**
FSSoundStreamHead defines the format of a streaming sound, identifying the encoding scheme, 
the rate at which the sound will be played and the size of the decoded samples. 
 
<p>The actual sound is streamed used the FSSoundStreamBlock class which contains 
the data for each frame in a movie.</p>

<table class="datasheet">

<tr><th align="left" colspan="2">Attributes</th></tr>

<tr><td><a name="FSSoundStreamHead_0">type</a></td>
<td>Identifies the data structure when it is encoded. Read-only.</td>
</tr>

<tr>
<td><a name="FSSoundStreamHead_1">format</a></td>
<td>The format of the encoded sound data - FSSound.PCM (Little0endian byte order), 
FSSound.ADPCM, or FSSound.NATIVE_PCM (Big-endian or Little-Endian byte order depending
on the platform where the sound was generated.).</td>
</tr>

<tr>
<td><a name="FSSoundStreamHead_2">playbackRate</a></td>
<td>The recommended playback rate in Hertz - 5512, 11025, 22050 or 44100.</td>
</tr>

<tr>
<td><a name="FSSoundStreamHead_3">playbackSampleSize</a></td>
<td>The number of bytes in an uncompressed sample when the sound is played, either 1 or 2.</td>
</tr>

<tr>
<td><a name="FSSoundStreamHead_4">playbackChannels</a></td>
<td>The recommended number of playback channels: 1 = mono or 2 = stereo.</td>
</tr>

<tr>
<td><a name="FSSoundStreamHead_5">streamRate</a></td>
<td>The rate at which the streaming sound was samples - 5512, 11025, 22050 or 44100 Hz.</td>
</tr>

<tr>
<td><a name="FSSoundStreamHead_6">streamSampleSize</a></td>
<td>The size of an uncompressed sample in the streaming sound in bytes, either 1 or 2.</td>
</tr>

<tr>
<td><a name="FSSoundStreamHead_7">streamChannels</a></td>
<td>The number of channels: 1 = mono or 2 = stereo, in the streaming sound</td>
</tr>

<tr>
<td><a name="FSSoundStreamHead_8">streamSampleCount</a></td>
<td>The average number of samples in each FSSoundStreamBlock object.</td>
</tr>

</table>

<p>Three encoded formats for the sound data are supported:</p>

<ul>
<li>NATIVE_PCM - uncompressed Pulse Code Modulated: samples are either 1 or 2 bytes. For two-byte samples the byte order is dependent on the platform on which the Flash Player is hosted. Sounds created on a platform which supports big-endian byte order will not be played correctly when listened to on a platform which supports little-endian byte order.</li>
<li>PCM - uncompressed Pulse Code Modulated: samples are either 1 or 2 bytes with 
the latter presented in Little-Endian byte order. This ensures that sounds can be played across different platforms.</li>
<li>ADPCM - compressed ADaptive Pulse Code Modulated: samples are encoded and compressed
by comparing the difference between successive sound sample which dramatically reduces
the size of the encoded sound when compared to the uncompressed PCM formats. Use this 
format whenever possible.</li>
</ul>

<p>Constants representing the different formats are defined in the FSSound class.</p>

<p>When a stream sound is played if the Flash Player cannot render the frames fast enough 
to maintain synchronisation with the sound being played then frames will be skipped. 
Normally the player will reduce the frame rate so every frame of a movie is played. 
The different sets of attributes that identify how the sound will be played compared 
to the way it was encoded allows the Player more control over how the animation is 
rendered. Reducing the resolution or playback rate can improve synchronisation with 
the frames displayed.</p>

<h1 class="datasheet">History</h1>

<p>The FSSoundStreamHead class represents the SoundStreamHead structure from the 
Macromedia Flash (SWF) File Format Specification. It was introduced in Flash 1.</p>
 */
public class FSSoundStreamHead extends FSMovieObject
{
    private int format = FSSound.ADPCM;

    private int playbackRate = 5512;
    private int playbackChannels = 1;
    private int playbackSampleSize = 16;

    private int streamRate = 5512;
    private int streamChannels = 1;
    private int streamSampleSize = 16;
    private int streamSampleCount = 0;
    private int latency = 0;

    /**
     * Construct an FSSoundStreamHead object, initalizing it with values decoded 
     * from an encoded object.
     * 
     * @param coder an FSCoder containing the binary data.
     */
    public FSSoundStreamHead(FSCoder coder)
    {
        super(FSMovieObject.SoundStreamHead);
        decode(coder);
    }
    /** Constructs an FSSoundStreamHead object specifying all the parameters required to define the sound.

        @param playRate the recommended rate for playing the sound, either 5512, 11025, 22050 or 44100 Hz.
        @param playChannels The recommended number of playback channels: 1 = mono or 2 = stereo.
        @param playSize the recommended uncompressed sample size for playing the sound, either 1 or 2 bytes.
        @param streamingRate the rate at which the sound was sampled, either 5512, 11025, 22050 or 44100 Hz.
        @param streamingChannels the number of channels: 1 = mono or 2 = stereo.
        @param streamingSize the sample size for the sound in bytes, either 1 or 2.
        @param streamingCount the number of samples in each subsequent FSSoundStreamBlock object.
        @param latency defines the number of samples to skip only when playing sounds encoded with the MP3 format.
        */
    public FSSoundStreamHead(int playRate, int playChannels, int playSize, int streamingRate, int streamingChannels, int streamingSize, int streamingCount, int latency)
    {
        super(FSMovieObject.SoundStreamHead);
        
        setPlaybackRate(playRate);
        setPlaybackChannels(playChannels);
        setPlaybackSampleSize(playSize);

        setStreamRate(streamingRate);
        setStreamChannels(streamingChannels);
        setStreamSampleSize(streamingSize);
        setStreamSampleCount(streamingCount);
        setLatency(latency);
    }
    /**
     * Constructs an FSSoundStreamHead object by copying values from an existing 
     * object.
     *
     * @param obj an FSSoundStreamHead object.
     */
    public FSSoundStreamHead(FSSoundStreamHead obj)
    {
        super(obj);
        format = obj.format;
        playbackRate = obj.playbackRate;
        playbackChannels = obj.playbackChannels;
        playbackSampleSize = obj.playbackSampleSize;
        
        streamRate = obj.streamRate;
        streamChannels = obj.streamChannels;
        streamSampleSize = obj.streamSampleSize;
        streamSampleCount = obj.streamSampleCount;
        latency = obj.latency;
    }
    
    /** Gets the streaming sound format. For the FSSoundStreamHead class supports 
     * ADPCM or MP3 encoded sound data.
    
        @return the format used to play the sound.
        */
    public int getFormat()
    {
        return format;
    }

    /** Sets the format for the streaming sound.

        @param encoding the compression format for the sound data, either 
        FSSound.ADPCM or FSSound.MP3.
    */
    public void setFormat(int encoding)
    {
        format = encoding;
    }

   /** Gets the recommended playback rate: 5512, 11025, 22050 or 44100 Hertz.

        @return the rate at which the sound will be played back.
        */
    public int getPlaybackRate() { return playbackRate; }

    /** Gets the recommended number of playback channels = 1 = mono 2 = stereo.

        @return the number of channels for the sound playback.
        */
    public int getPlaybackChannels() { return playbackChannels; }

    /** Gets the recommended playback sample range in bytes: 1 or 2.

        @return the sample size used to play back the sound.
        */
    public int getPlaybackSampleSize() { return playbackSampleSize; }

    /** Gets the sample rate: 5512, 11025, 22050 or 44100 Hz in the streaming sound.

        @return the rate at which the sound was sampled.
        */
    public float getStreamRate() { return streamRate; }

    /** Gets the number of channels, 1 = mono 2 = stereo, in the streaming sound.

        @return the number of channels in the sound.
        */
    public int getStreamChannels() { return streamChannels; }

    /** Gets the sample size in bytes: 1 or 2 in the streaming sound.

        @return the sample size.
        */
    public int getStreamSampleSize() { return streamSampleSize; }