cleanup, optimizations

This commit is contained in:
chudov
2009-08-17 20:16:56 +00:00
parent ea0afc6273
commit bc2aceebda
4 changed files with 394 additions and 250 deletions

View File

@@ -4,19 +4,39 @@ using System.Text;
namespace CUETools.Codecs.FLAKE
{
class BitReader
unsafe class BitReader
{
byte[] buffer;
byte[] byte_to_unary_table;
byte* buffer;
int pos, len;
int _bitaccumulator;
uint cache;
static readonly byte[] byte_to_unary_table = new byte[]
{
8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
public int Position
{
get { return pos; }
}
public byte[] Buffer
public byte* Buffer
{
get
{
@@ -24,110 +44,93 @@ namespace CUETools.Codecs.FLAKE
}
}
public BitReader(byte[] _buffer, int _pos, int _len)
public BitReader(byte* _buffer, int _pos, int _len)
{
buffer = _buffer;
pos = _pos;
len = _len;
_bitaccumulator = 0;
byte_to_unary_table = new byte[] {
8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
cache = peek4();
}
/* supports reading 1 to 24 bits, in big endian format */
public uint readbits_24(int bits)
public uint peek4()
{
uint result = (((uint)buffer[pos]) << 24) | (((uint)buffer[pos + 1]) << 16) | (((uint)buffer[pos + 2]) << 8) | ((uint)buffer[pos + 3]);
//uint result = ((((uint)buffer[pos]) << 24) | (((uint)buffer[pos + 1]) << 16) | (((uint)buffer[pos + 2]) << 8) | ((uint)buffer[pos + 3])) << _bitaccumulator;
byte* b = buffer + pos;
uint result = *(b++);
result = (result << 8) + *(b++);
result = (result << 8) + *(b++);
result = (result << 8) + *(b++);
result <<= _bitaccumulator;
result >>= 32 - bits;
int new_accumulator = (_bitaccumulator + bits);
pos += (new_accumulator >> 3);
_bitaccumulator = (new_accumulator & 7);
return result;
}
public uint readbits_8(int bits)
{
uint result = (((uint)buffer[pos]) << 24) | (((uint)buffer[pos + 1]) << 16);
result <<= _bitaccumulator;
result >>= 32 - bits;
int new_accumulator = (_bitaccumulator + bits);
pos += (new_accumulator >> 3);
_bitaccumulator = (new_accumulator & 7);
return result;
}
public uint peekbits_24(int bits)
{
uint result = (((uint)buffer[pos]) << 24) | (((uint)buffer[pos + 1]) << 16) | (((uint)buffer[pos + 2]) << 8) | ((uint)buffer[pos + 3]);
result <<= _bitaccumulator;
result >>= 32 - bits;
return result;
}
///* supports reading 1 to 16 bits, in big endian format */
//private unsafe uint peekbits_9(byte* buff, int pos)
//{
// uint result = (((uint)buff[pos]) << 8) | (((uint)buff[pos + 1]));
// result <<= _bitaccumulator;
// result &= 0x0000ffff;
// result >>= 7;
// return result;
//}
/* supports reading 1 to 16 bits, in big endian format */
/* skip any number of bits */
public void skipbits(int bits)
{
int new_accumulator = (_bitaccumulator + bits);
pos += (new_accumulator >> 3);
_bitaccumulator = (new_accumulator & 7);
cache = peek4();
}
/* skip up to 8 bits */
public void skipbits8(int bits)
{
cache <<= bits;
int new_accumulator = (_bitaccumulator + bits);
pos += (new_accumulator >> 3);
_bitaccumulator = (new_accumulator & 7);
cache |= ((uint)buffer[pos + 3] << _bitaccumulator);
}
/* supports reading 1 to 24 bits, in big endian format */
public uint readbits24(int bits)
{
//uint result = peek4() >> (32 - bits);
uint result = cache >> (32 - bits);
skipbits(bits);
return result;
}
public uint peekbits24(int bits)
{
return cache >> 32 - bits;
}
/* supports reading 1 to 32 bits, in big endian format */
public uint readbits(int bits)
{
uint result = cache >> 32 - bits;
if (bits <= 24)
return readbits_24(bits);
{
skipbits(bits);
return result;
}
skipbits(24);
result |= cache >> 56 - bits;
skipbits(bits - 24);
return result;
}
ulong result = (((ulong)buffer[pos]) << 32) | (((ulong)buffer[pos + 1]) << 24) | (((ulong)buffer[pos + 2]) << 16) | (((ulong)buffer[pos + 3]) << 8) | ((ulong)buffer[pos + 4]);
result <<= _bitaccumulator;
result &= 0x00ffffffffff;
result >>= 40 - bits;
int new_accumulator = (_bitaccumulator + bits);
pos += (new_accumulator >> 3);
_bitaccumulator = (new_accumulator & 7);
return (uint)result;
public ulong readbits64(int bits)
{
if (bits <= 24)
return readbits24(bits);
ulong result = readbits24(24);
bits -= 24;
if (bits <= 24)
return (result << bits) | readbits24(bits);
result = (result << 24) | readbits24(24);
bits -= 24;
return (result << bits) | readbits24(bits);
}
/* reads a single bit */
public uint readbit()
{
int new_accumulator;
uint result = buffer[pos];
result <<= _bitaccumulator;
result = result >> 7 & 1;
new_accumulator = (_bitaccumulator + 1);
pos += (new_accumulator / 8);
_bitaccumulator = (new_accumulator % 8);
uint result = cache >> 31;
skipbits8(1);
return result;
}
@@ -135,33 +138,28 @@ namespace CUETools.Codecs.FLAKE
{
uint val = 0;
int result = (buffer[pos] << _bitaccumulator) & 0xff;
if (result == 0)
uint result = cache >> 24;
while (result == 0)
{
val = 8 - (uint)_bitaccumulator;
_bitaccumulator = 0;
pos++;
return val + read_unary();
// check eof
val += 8;
skipbits8(8);
result = cache >> 24;
}
val = byte_to_unary_table[result];
int new_accumulator = (_bitaccumulator + (int)val + 1);
pos += (new_accumulator / 8);
_bitaccumulator = (new_accumulator % 8);
val += byte_to_unary_table[result];
skipbits8((int)(val & 7) + 1);
return val;
}
public void flush()
{
if (_bitaccumulator > 0)
readbits(8 - _bitaccumulator);
skipbits8(8 - _bitaccumulator);
}
public int readbits_signed(int bits)
{
int val = (int) readbits(bits);
int val = (int)readbits(bits);
val <<= (32 - bits);
val >>= (32 - bits);
return val;
@@ -223,15 +221,7 @@ namespace CUETools.Codecs.FLAKE
public int read_rice_signed(int k)
{
uint msbs = read_unary();
uint lsbs = readbits_24(k);
uint uval = (msbs << k) | lsbs;
return (int)(uval >> 1 ^ -(int)(uval & 1));
}
public int read_rice_signed8(int k)
{
uint msbs = read_unary();
uint lsbs = readbits_8(k);
uint lsbs = readbits24(k);
uint uval = (msbs << k) | lsbs;
return (int)(uval >> 1 ^ -(int)(uval & 1));
}
@@ -241,5 +231,49 @@ namespace CUETools.Codecs.FLAKE
uint uval = read_unary();
return (int)(uval >> 1 ^ -(int)(uval & 1));
}
public void read_rice_block(int n, int k, int* r)
{
fixed (byte* unary_table = byte_to_unary_table)
{
if (k == 0)
for (int i = n; i > 0; i--)
*(r++) = read_unary_signed();
else if (k <= 8)
for (int i = n; i > 0; i--)
{
//*(r++) = read_rice_signed((int)k);
uint bits = unary_table[cache >> 24];
uint msbs = bits;
while (bits == 8)
{
skipbits8(8);
bits = unary_table[cache >> 24];
msbs += bits;
}
skipbits8((int)(msbs & 7) + 1);
uint uval = (msbs << k) | (cache >> (32 - k));
skipbits8(k);
*(r++) = (int)(uval >> 1 ^ -(int)(uval & 1));
}
else
for (int i = n; i > 0; i--)
{
//*(r++) = read_rice_signed((int)k);
uint bits = unary_table[cache >> 24];
uint msbs = bits;
while (bits == 8)
{
skipbits8(8);
bits = unary_table[cache >> 24];
msbs += bits;
}
skipbits8((int)(msbs & 7) + 1);
uint uval = (msbs << k) | (cache >> (32 - k));
skipbits(k);
*(r++) = (int)(uval >> 1 ^ -(int)(uval & 1));
}
}
}
}
}