block.java

java ogg player library. for play back ogg audio

/* JOrbis
 * Copyright (C) 2000 ymnk, JCraft,Inc.
 *  
 * Written by: 2000 ymnk<[e-mail]>
 *   
 * Many thanks to 
 *   Monty <[e-mail]> and 
 *   The XIPHOPHORUS Company http://www.xiph.org/ .
 * JOrbis has been based on their awesome works, Vorbis codec.
 *   
 * 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 com.jcraft.jorbis;

import com.jcraft.jogg.*;

public class Block{
  ///necessary stream state for linking to the framing abstraction
  float[][] pcm=new float[0][]; // this is a pointer into local storage
  Buffer opb=new Buffer();
  
  int lW;
  int W;
  int nW;
  int pcmend;
  int mode;

  int eofflag;
  long granulepos;
  long sequence;
  DspState vd; // For read-only access of configuration

  // local storage to avoid remallocing; it's up to the mapping to
  // structure it
//byte[] localstore;
//int  localtop;
//int  localalloc;
//int  totaluse;
//AllocChain reap;

  // bitmetrics for the frame
  int glue_bits;
  int time_bits;
  int floor_bits;
  int res_bits;

  public Block(DspState vd){
    this.vd=vd;
//  localalloc=0;
//  localstore=null;
    if(vd.analysisp!=0){
      opb.writeinit();
    }
  }

  public void init(DspState vd){
    this.vd=vd;
  }

//  int alloc(int bytes){
//    bytes=(bytes+(8-1))&(~(8-1));
//    if(bytes+localtop>localalloc){
//      if(localstore!=null){
//	AllocChain link=new AllocChain();
//	totaluse+=localtop;
//	link.next=reap;
//	link.ptr=localstore;
//	reap=link;
//      }
//      // highly conservative
//      localalloc=bytes;
//      localstore=new byte[localalloc];
//      localtop=0;
//    }
//    {
//      int foo=localtop;
//      //void *ret=(void *)(((char *)vb->localstore)+vb->localtop);
//      localtop+=bytes;
//      return foo;
//    }
//  }

  // reap the chain, pull the ripcord
//  void ripcord(){
//    // reap the chain
//    while(reap!=null){
//      AllocChain next=reap.next;
//      //free(reap->ptr);
//      reap.ptr=null;
//      //memset(reap,0,sizeof(struct alloc_chain));
//      //free(reap);
//      reap=next;
//    }
//    // consolidate storage
//    if(totaluse!=0){
//      //vb->localstore=realloc(vb->localstore,vb->totaluse+vb->localalloc);
//      byte[] foo=new byte[totaluse+localalloc];
//      System.arraycopy(localstore, 0, foo, 0, localstore.length);
//      localstore=foo;
//      localalloc+=totaluse;
//      totaluse=0;
//    }
//    // pull the ripcord
//    localtop=0;
//    reap=null;
//  }

  public int clear(){
    if(vd!=null){
      if(vd.analysisp!=0){
	opb.writeclear();
      }
    }
    //ripcord();
    //if(localstore!=null)
    //  localstore=null;
    //memset(vb,0,sizeof(vorbis_block));
    return(0);
  }

  public int synthesis(Packet op){
    Info vi=vd.vi;
 
    // first things first.  Make sure decode is ready
    // ripcord();
    opb.readinit(op.packet_base, op.packet, op.bytes);

    // Check the packet type
    if(opb.read(1)!=0){
      // Oops.  This is not an audio data packet
      return(-1);
    }

    // read our mode and pre/post windowsize
    int _mode=opb.read(vd.modebits);
    if(_mode==-1)return(-1);
  
    mode=_mode;
    W=vi.mode_param[mode].blockflag;
    if(W!=0){
      lW=opb.read(1);
      nW=opb.read(1);
      if(nW==-1) return(-1);
    }
    else{
      lW=0;
      nW=0;
    }
  
    // more setup
    granulepos=op.granulepos;
    sequence=op.packetno-3; // first block is third packet
    eofflag=op.e_o_s;

    // alloc pcm passback storage
    pcmend=vi.blocksizes[W];
    //pcm=alloc(vi.channels);
    if(pcm.length<vi.channels){
      pcm=new float[vi.channels][];
    }
    for(int i=0;i<vi.channels;i++){
      if(pcm[i]==null || pcm[i].length<pcmend){
        pcm[i]=new float[pcmend];
        //pcm[i]=alloc(pcmend);
      }
      else{
        for(int j=0;j<pcmend;j++){ pcm[i][j]=0; }
      }
    }

    // unpack_header enforces range checking
    int type=vi.map_type[vi.mode_param[mode].mapping];
    return(FuncMapping.mapping_P[type].inverse(this, vd.mode[mode]));
  }
}