streamstate.java

来自「java ogg player library. for play back o」· Java 代码 · 共 658 行 · 第 1/2 页

/* 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.jogg;

public class StreamState{
  byte[] body_data;    /* bytes from packet bodies */
  int body_storage;    /* storage elements allocated */
  int body_fill;       /* elements stored; fill mark */
private  int body_returned;   /* elements of fill returned */


  int[] lacing_vals;    /* The values that will go to the segment table */
  long[] granule_vals;  /* pcm_pos values for headers. Not compact
			   this way, but it is simple coupled to the
			   lacing fifo */
  int lacing_storage;
  int lacing_fill;
  int lacing_packet;
  int lacing_returned;

  byte[] header=new byte[282];      /* working space for header encode */
  int header_fill;

  public int e_o_s;   /* set when we have buffered the last packet in the
			 logical bitstream */
  int b_o_s;          /* set after we've written the initial page
			 of a logical bitstream */
  int serialno;
  int pageno;
  long packetno;      /* sequence number for decode; the framing
                         knows where there's a hole in the data,
                         but we need coupling so that the codec
                         (which is in a seperate abstraction
                         layer) also knows about the gap */
  long granulepos;

  public StreamState(){
    init();
  }

  StreamState(int serialno){
    this();
    init(serialno);
  }
  void init(){
    body_storage=16*1024;
    body_data=new byte[body_storage];
    lacing_storage=1024;
    lacing_vals=new int[lacing_storage];
    granule_vals=new long[lacing_storage];
  }
  public void init(int serialno){
    if(body_data==null){ init(); }
    else{
      for(int i=0; i<body_data.length; i++) body_data[i]=0;
      for(int i=0; i<lacing_vals.length; i++) lacing_vals[i]=0;
      for(int i=0; i<granule_vals.length; i++) granule_vals[i]=0;
    }
    this.serialno=serialno;
  }
  public void clear(){
    body_data=null;
    lacing_vals=null;
    granule_vals=null;
    //memset(os,0,sizeof(ogg_stream_state));    
  }
  void destroy(){
    clear();
  }
  void body_expand(int needed){
    if(body_storage<=body_fill+needed){
      body_storage+=(needed+1024);
      byte[] foo=new byte[body_storage];
      System.arraycopy(body_data, 0, foo, 0, body_data.length);
      body_data=foo;
//System.out.println("expand: body_fill="+body_fill+", body_storage="+body_data.length);
    }
  }
  void lacing_expand(int needed){
    if(lacing_storage<=lacing_fill+needed){
      lacing_storage+=(needed+32);
      int[] foo=new int[lacing_storage];
      System.arraycopy(lacing_vals, 0, foo, 0, lacing_vals.length);
      lacing_vals=foo;

      long[] bar=new long[lacing_storage];
      System.arraycopy(granule_vals, 0, bar, 0, granule_vals.length);
      granule_vals=bar;
    }
  }

  /* submit data to the internal buffer of the framing engine */
  public int packetin(Packet op){
    int lacing_val=op.bytes/255+1;

    if(body_returned!=0){
      /* advance packet data according to the body_returned pointer. We
         had to keep it around to return a pointer into the buffer last
         call */
    
      body_fill-=body_returned;
      if(body_fill!=0){
//        memmove(os->body_data,os->body_data+os->body_returned,
//  	        os->body_fill*sizeof(char));
        System.arraycopy(body_data, body_returned, body_data, 0, body_fill);
      }
      body_returned=0;
    }

    /* make sure we have the buffer storage */
    body_expand(op.bytes);
    lacing_expand(lacing_val);

  /* Copy in the submitted packet.  Yes, the copy is a waste; this is
     the liability of overly clean abstraction for the time being.  It
     will actually be fairly easy to eliminate the extra copy in the
     future */

    System.arraycopy(op.packet_base, op.packet, body_data, body_fill, op.bytes);
    body_fill+=op.bytes;
//System.out.println("add: "+body_fill);

  /* Store lacing vals for this packet */
    int j;
    for(j=0;j<lacing_val-1;j++){
      lacing_vals[lacing_fill+j]=255;
      granule_vals[lacing_fill+j]=granulepos;
    }
    lacing_vals[lacing_fill+j]=(op.bytes)%255;
    granulepos=granule_vals[lacing_fill+j]=op.granulepos;

  /* flag the first segment as the beginning of the packet */
    lacing_vals[lacing_fill]|= 0x100;

    lacing_fill+=lacing_val;

  /* for the sake of completeness */
    packetno++;

    if(op.e_o_s!=0)e_o_s=1;
    return(0);
  }

  public int packetout(Packet op){

  /* The last part of decode. We have the stream broken into packet
     segments.  Now we need to group them into packets (or return the
     out of sync markers) */

    int ptr=lacing_returned;

    if(lacing_packet<=ptr){
      return(0);
    }

    if((lacing_vals[ptr]&0x400)!=0){
    /* We lost sync here; let the app know */
      lacing_returned++;

    /* we need to tell the codec there's a gap; it might need to
       handle previous packet dependencies. */
      packetno++;
      return(-1);
    }

  /* Gather the whole packet. We'll have no holes or a partial packet */
    {
      int size=lacing_vals[ptr]&0xff;
      int bytes=0;

      op.packet_base=body_data;
      op.packet=body_returned;
      op.e_o_s=lacing_vals[ptr]&0x200; /* last packet of the stream? */
      op.b_o_s=lacing_vals[ptr]&0x100; /* first packet of the stream? */
      bytes+=size;

      while(size==255){
	int val=lacing_vals[++ptr];
	size=val&0xff;
	if((val&0x200)!=0)op.e_o_s=0x200;
	bytes+=size;
      }

      op.packetno=packetno;
      op.granulepos=granule_vals[ptr];
      op.bytes=bytes;

//System.out.println(this+" # body_returned="+body_returned);
      body_returned+=bytes;
//System.out.println(this+"## body_returned="+body_returned);

      lacing_returned=ptr+1;
    }
    packetno++;
    return(1);
  }


  // add the incoming page to the stream state; we decompose the page
  // into packet segments here as well.

  public int pagein(Page og){
    byte[] header_base=og.header_base;
    int header=og.header;
    byte[] body_base=og.body_base;
    int body=og.body;
    int bodysize=og.body_len;
    int segptr=0;

    int version=og.version();
    int continued=og.continued();
    int bos=og.bos();
    int eos=og.eos();
    long granulepos=og.granulepos();
    int _serialno=og.serialno();
    int _pageno=og.pageno();
    int segments=header_base[header+26]&0xff;

    // clean up 'returned data'
    {
      int lr=lacing_returned;
      int br=body_returned;

      // body data

//System.out.println("br="+br+", body_fill="+body_fill);

      if(br!=0){
        body_fill-=br;
        if(body_fill!=0){
	  System.arraycopy(body_data, br, body_data, 0, body_fill);
	}
	body_returned=0;
      }

//System.out.println("?? br="+br+", body_fill="+body_fill+" body_returned="+body_returned);

      if(lr!=0){
        // segment table
	if((lacing_fill-lr)!=0){
	  System.arraycopy(lacing_vals, lr, lacing_vals, 0, lacing_fill-lr);
	  System.arraycopy(granule_vals, lr, granule_vals, 0, lacing_fill-lr);
	}
	lacing_fill-=lr;
	lacing_packet-=lr;
	lacing_returned=0;
      }
    }

    // check the serial number
    if(_serialno!=serialno)return(-1);
    if(version>0)return(-1);

    lacing_expand(segments+1);

    // are we in sequence?
    if(_pageno!=pageno){
      int i;

      // unroll previous partial packet (if any)
      for(i=lacing_packet;i<lacing_fill;i++){
	body_fill-=lacing_vals[i]&0xff;
//System.out.println("??");
      }
      lacing_fill=lacing_packet;

      // make a note of dropped data in segment table
      if(pageno!=-1){
	lacing_vals[lacing_fill++]=0x400;
	lacing_packet++;
      }

      // are we a 'continued packet' page?  If so, we'll need to skip
      // some segments
      if(continued!=0){
	bos=0;
	for(;segptr<segments;segptr++){
	  int val=(header_base[header+27+segptr]&0xff);
	  body+=val;
	  bodysize-=val;
	  if(val<255){
	    segptr++;
	    break;
	  }
	}
      }
    }

//System.out.println("bodysize="+bodysize);

    if(bodysize!=0){
      body_expand(bodysize);
      System.arraycopy(body_base, body, body_data, body_fill, bodysize);
      body_fill+=bodysize;
    }

//System.out.println("bodyfill="+body_fill);

    {
      int saved=-1;
      while(segptr<segments){
	int val=(header_base[header+27+segptr]&0xff);
	lacing_vals[lacing_fill]=val;
	granule_vals[lacing_fill]=-1;
      
	if(bos!=0){