namespace NSpeex
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{
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using System;
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internal class Bits
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{
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private int bitPtr = 0;
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private int bytePtr = 0;
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private byte[] bytes = new byte[0x400];
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public const int DefaultBufferSize = 0x400;
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private int nbBits;
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public void Advance(int n)
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{
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this.bytePtr += n >> 3;
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this.bitPtr += n & 7;
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if (this.bitPtr > 7)
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{
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this.bitPtr -= 8;
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this.bytePtr++;
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}
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}
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public int BitsRemaining { get { return (this.nbBits - ((this.bytePtr * 8) + this.bitPtr)); } }
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public void InsertTerminator()
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{
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if (this.bitPtr > 0)
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{
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this.Pack(0, 1);
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}
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while (this.bitPtr != 0)
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{
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this.Pack(1, 1);
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}
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}
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public void Pack(int data, int nbBits)
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{
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int num = data;
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while ((this.bytePtr + ((nbBits + this.bitPtr) >> 3)) >= this.bytes.Length)
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{
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int num2 = this.bytes.Length * 2;
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byte[] destinationArray = new byte[num2];
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Array.Copy(this.bytes, 0, destinationArray, 0, this.bytes.Length);
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this.bytes = destinationArray;
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}
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while (nbBits > 0)
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{
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int num3 = (num >> (nbBits - 1)) & 1;
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this.bytes[this.bytePtr] = (byte)(this.bytes[this.bytePtr] | ((byte)(num3 << (7 - this.bitPtr))));
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this.bitPtr++;
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if (this.bitPtr == 8)
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{
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this.bitPtr = 0;
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this.bytePtr++;
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}
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nbBits--;
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}
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}
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public int Peek { get { return (((this.bytes[this.bytePtr] & 0xff) >> (7 - this.bitPtr)) & 1); } }
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public void ReadFrom(byte[] newbytes, int offset, int len)
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{
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for (int i = 0; i < len; i++)
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{
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this.bytes[i] = newbytes[offset + i];
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}
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this.bytePtr = 0;
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this.bitPtr = 0;
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this.nbBits = len * 8;
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}
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public void Reset()
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{
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Array.Clear(this.bytes, 0, this.bytes.Length);
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this.bytePtr = 0;
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this.bitPtr = 0;
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}
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public int Unpack(int nbBits)
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{
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int num = 0;
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while (nbBits != 0)
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{
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num = num << 1;
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num |= ((this.bytes[this.bytePtr] & 0xff) >> (7 - this.bitPtr)) & 1;
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this.bitPtr++;
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if (this.bitPtr == 8)
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{
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this.bitPtr = 0;
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this.bytePtr++;
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}
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nbBits--;
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}
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return num;
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}
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public int Write(byte[] buffer, int offset, int maxBytes)
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{
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int bitPtr = this.bitPtr;
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int bytePtr = this.bytePtr;
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byte[] bytes = this.bytes;
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this.InsertTerminator();
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this.bitPtr = bitPtr;
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this.bytePtr = bytePtr;
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this.bytes = bytes;
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if (maxBytes > this.BufferSize)
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{
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maxBytes = this.BufferSize;
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}
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Array.Copy(this.bytes, 0, buffer, offset, maxBytes);
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return maxBytes;
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}
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public int BufferSize { get { return (this.bytePtr + ((this.bitPtr > 0) ? 1 : 0)); } }
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}
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}
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