www.pudn.com > jlayermp3midlet.rar > BitReserve.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; 
 
final class BitReserve { 
  private final static int BUFSIZE = 4096 * 8; 
  private final static int BUFSIZE_MASK = BUFSIZE - 1; 
  static int offset,buf_byte_idx; 
  private static final int[] buf = new int[BUFSIZE]; 
  static int buf_bit_idx; 
  public static int totbit; 
  //public int hsstell() { 
  //  return totbit; 
  //} 
 
  public final int hgetbits(int N) { 
   totbit += N; 
    val=0; 
    if (buf_byte_idx + N < BUFSIZE) { 
      while (N-- > 0) { 
        val <<= 1; 
        val |= ((buf[buf_byte_idx++] == 0) ? 0 : 1); 
      } 
    } 
    else { 
      while (N-- > 0) { 
        val <<= 1; 
        val |= ((buf[buf_byte_idx] == 0) ? 0 : 1); 
        buf_byte_idx = (buf_byte_idx + 1) & BUFSIZE_MASK; 
      } 
    } 
 
    return val; 
  
   } 
 
 
  static int val; 
 
  public final int hget1bit() { 
    totbit++; 
    val = buf[buf_byte_idx]; 
    buf_byte_idx = (buf_byte_idx + 1) & BUFSIZE_MASK; 
    return val; 
  } 
 
  public final void hputbuf(int val) { 
    buf[offset++] = val & 0x80; 
    buf[offset++] = val & 0x40; 
    buf[offset++] = val & 0x20; 
    buf[offset++] = val & 0x10; 
    buf[offset++] = val & 0x08; 
    buf[offset++] = val & 0x04; 
    buf[offset++] = val & 0x02; 
    buf[offset++] = val & 0x01; 
    if (offset == BUFSIZE) 
      offset = 0; 
  } 
 
 
  public final void rewindNbits(int N) { 
    totbit -= N; 
    buf_byte_idx -= N; 
    if (buf_byte_idx < 0) { 
      buf_byte_idx += BUFSIZE; 
    } 
  } 
 
  static int bits; 
  public final void rewindNbytes(int N) { 
    bits = (N << 3); 
    totbit -= bits; 
    buf_byte_idx -= bits; 
    if (buf_byte_idx < 0) { 
      buf_byte_idx += BUFSIZE; 
    } 
  } 
 
}