www.pudn.com > jlayermp3midlet.rar > Decoder.java

/** 
 *----------------------------------------------------------------------- 
 *   This program is free software; you can redistribute it and/or modify 
 *   it under the terms of the GNU Library General Public License as published 
 *   by the Free Software Foundation; either version 2 of the License,or 
 *   (at your option) any later version. 
 * 
 *   This program 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 Library General Public License for more details. 
 * 
 *   You should have received a copy of the GNU Library General Public 
 *   License along with this program; if not,write to the Free Software 
 *   Foundation,Inc.,675 Mass Ave,Cambridge,MA 02139,USA. 
 *---------------------------------------------------------------------- 
 */ 
package javazoom.jlme.decoder; 
 
 
public class Decoder { 
  private SampleBuffer output; 
  private SynthesisFilter filter1; 
  private SynthesisFilter filter2; 
  private LayerIIIDecoder decoder; 
  private int outputFrequency; 
  private int outputChannels; 
  private boolean initialized; 
  protected Header hd; 
 
  /** 
   *  Constructor for the Decoder object 
   *@param  header  Description of Parameter 
   *@param  stream  Description of Parameter 
   */ 
  public Decoder(Header header,BitStream stream) { 
	// E.B Fix - Damned unloaded static fields ! 
    System.gc(); 
    hd=header; 
    BitReserve.totbit = 0; 
    BitReserve.buf_bit_idx=0; 
    BitReserve.buf_byte_idx=0; 
    BitReserve.offset=0; 
    // End of fix. 
    if (header.layer() == 3) { 
      //float scalefactor = 48000.0f; 
      float scalefactor = 32700.0f; 
      int mode = header.mode(); 
      int layer = header.layer(); 
      int channels = mode == Header.SINGLE_CHANNEL ? 1 : 2; 
      output = new SampleBuffer(header.frequency(),channels); 
      filter1 = new SynthesisFilter(0,scalefactor); 
      if (channels == 2) { 
        filter2 = new SynthesisFilter(1,scalefactor); 
      } 
      outputChannels = channels; 
      outputFrequency = header.frequency(); 
      decoder = new LayerIIIDecoder(stream,header,filter1,filter2,output,OutputChannels.BOTH_CHANNELS); 
    } 
    else { 
      System.out.println("only supports mp3 files"); 
      System.exit(1); 
    } 
  } 
 
  /** 
   *  Sets the outputBuffer attribute of the Decoder object 
   *@param  out  The new outputBuffer value 
   */ 
  public final void setOutputBuffer(SampleBuffer out) { 
    output = out; 
  } 
 
  /** 
   *  Gets the outputFrequency attribute of the Decoder object 
   *@return    The outputFrequency value 
   */ 
  public final int getOutputFrequency() { 
    return outputFrequency; 
  } 
 
  /** 
   *  Gets the outputChannels attribute of the Decoder object 
   *@return    The outputChannels value 
   */ 
  public final int getOutputChannels() { 
    return outputChannels; 
  } 
 
  /** 
   *  Gets the outputBlockSize attribute of the Decoder object 
   *@return    The outputBlockSize value 
   */ 
  public final int getOutputBlockSize() { 
    return SampleBuffer.OBUFFERSIZE; 
  } 
 
  /** 
   *  Description of the Method 
   *@return    Description of the Returned Value 
   */ 
  public final SampleBuffer decodeFrame() { 
    output.clear(); 
    decoder.decodeFrame(); 
    return output; 
  } 
}