Managed FLAC encoder/decoder based on Flake, initial revision

This commit is contained in:
chudov
2009-08-17 03:39:53 +00:00
parent 83cfd28d6b
commit ea0afc6273
8 changed files with 3692 additions and 0 deletions

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using System;
using System.Collections.Generic;
using System.Text;
namespace CUETools.Codecs.FLAKE
{
class BitReader
{
byte[] buffer;
byte[] byte_to_unary_table;
int pos, len;
int _bitaccumulator;
public int Position
{
get { return pos; }
}
public byte[] Buffer
{
get
{
return buffer;
}
}
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
};
}
/* supports reading 1 to 24 bits, in big endian format */
public uint readbits_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;
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 */
public void skipbits(int bits)
{
int new_accumulator = (_bitaccumulator + bits);
pos += (new_accumulator >> 3);
_bitaccumulator = (new_accumulator & 7);
}
/* supports reading 1 to 32 bits, in big endian format */
public uint readbits(int bits)
{
if (bits <= 24)
return readbits_24(bits);
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;
}
/* 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);
return result;
}
public uint read_unary()
{
uint val = 0;
int result = (buffer[pos] << _bitaccumulator) & 0xff;
if (result == 0)
{
val = 8 - (uint)_bitaccumulator;
_bitaccumulator = 0;
pos++;
return val + read_unary();
// check eof
}
val = byte_to_unary_table[result];
int new_accumulator = (_bitaccumulator + (int)val + 1);
pos += (new_accumulator / 8);
_bitaccumulator = (new_accumulator % 8);
return val;
}
public void flush()
{
if (_bitaccumulator > 0)
readbits(8 - _bitaccumulator);
}
public int readbits_signed(int bits)
{
int val = (int) readbits(bits);
val <<= (32 - bits);
val >>= (32 - bits);
return val;
}
public uint read_utf8()
{
uint x = readbits(8);
uint v;
int i;
if (0 == (x & 0x80))
{
v = x;
i = 0;
}
else if (0xC0 == (x & 0xE0)) /* 110xxxxx */
{
v = x & 0x1F;
i = 1;
}
else if (0xE0 == (x & 0xF0)) /* 1110xxxx */
{
v = x & 0x0F;
i = 2;
}
else if (0xF0 == (x & 0xF8)) /* 11110xxx */
{
v = x & 0x07;
i = 3;
}
else if (0xF8 == (x & 0xFC)) /* 111110xx */
{
v = x & 0x03;
i = 4;
}
else if (0xFC == (x & 0xFE)) /* 1111110x */
{
v = x & 0x01;
i = 5;
}
else if (0xFE == x) /* 11111110 */
{
v = 0;
i = 6;
}
else
throw new Exception("invalid utf8 encoding");
for (; i > 0; i--)
{
x = readbits(8);
if (0x80 != (x & 0xC0)) /* 10xxxxxx */
throw new Exception("invalid utf8 encoding");
v <<= 6;
v |= (x & 0x3F);
}
return v;
}
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 uval = (msbs << k) | lsbs;
return (int)(uval >> 1 ^ -(int)(uval & 1));
}
public int read_unary_signed()
{
uint uval = read_unary();
return (int)(uval >> 1 ^ -(int)(uval & 1));
}
}
}

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using System;
using System.Collections.Generic;
using System.Text;
namespace CUETools.Codecs.FLAKE
{
class BitWriter
{
uint bit_buf;
int bit_left;
byte[] buffer;
int buf_start, buf_ptr, buf_end;
bool eof;
public BitWriter(byte[] buf, int pos, int len)
{
buffer = buf;
buf_start = pos;
buf_ptr = pos;
buf_end = pos + len;
bit_left = 32;
bit_buf = 0;
eof = false;
}
public void writebits_signed(int bits, int val)
{
writebits(bits, val & ((1 << bits) - 1));
}
public void writebits_signed(uint bits, int val)
{
writebits((int) bits, val & ((1 << (int) bits) - 1));
}
public void writebits(int bits, int val)
{
writebits(bits, (uint)val);
}
public void writebits(int bits, uint val)
{
//assert(bits == 32 || val < (1U << bits));
if (bits == 0 || eof) return;
if ((buf_ptr + 3) >= buf_end)
{
eof = true;
return;
}
if (bits < bit_left)
{
bit_buf = (bit_buf << bits) | val;
bit_left -= bits;
}
else
{
uint bb = 0;
if (bit_left == 32)
{
//assert(bits == 32);
bb = val;
}
else
{
bb = (bit_buf << bit_left) | (val >> (bits - bit_left));
bit_left += (32 - bits);
}
if (buffer != null)
{
buffer[buf_ptr + 3] = (byte)(bb & 0xFF); bb >>= 8;
buffer[buf_ptr + 2] = (byte)(bb & 0xFF); bb >>= 8;
buffer[buf_ptr + 1] = (byte)(bb & 0xFF); bb >>= 8;
buffer[buf_ptr + 0] = (byte)(bb & 0xFF);
}
buf_ptr += 4;
bit_buf = val;
}
}
public void write_utf8(int val)
{
write_utf8((uint)val);
}
public void write_utf8(uint val)
{
if (val < 0x80)
{
writebits(8, val);
return;
}
int bytes = (Flake.log2i(val) + 4) / 5;
int shift = (bytes - 1) * 6;
writebits(8, (256U - (256U >> bytes)) | (val >> shift));
while (shift >= 6)
{
shift -= 6;
writebits(8, 0x80 | ((val >> shift) & 0x3F));
}
}
public void write_rice_signed(int k, int val)
{
int v, q;
if (k < 0) return;
// convert signed to unsigned
v = -2 * val - 1;
v ^= (v >> 31);
// write quotient in unary
q = (v >> k) + 1;
while (q > 31)
{
writebits(31, 0);
q -= 31;
}
writebits(q, 1);
// write write remainder in binary using 'k' bits
writebits(k, v & ((1 << k) - 1));
}
public void flush()
{
bit_buf <<= bit_left;
while (bit_left < 32 && !eof)
{
if (buf_ptr >= buf_end)
{
eof = true;
break;
}
if (buffer != null)
buffer[buf_ptr] = (byte)(bit_buf >> 24);
buf_ptr++;
bit_buf <<= 8;
bit_left += 8;
}
bit_left = 32;
bit_buf = 0;
}
public int Length
{
get
{
return buf_ptr - buf_start;
}
}
}
}

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<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
<Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
<ProductVersion>8.0.50727</ProductVersion>
<SchemaVersion>2.0</SchemaVersion>
<ProjectGuid>{082D6B9E-326E-4D15-9798-EDAE9EDE70A6}</ProjectGuid>
<OutputType>Library</OutputType>
<AppDesignerFolder>Properties</AppDesignerFolder>
<RootNamespace>CUETools.Codecs.FLAKE</RootNamespace>
<AssemblyName>CUETools.Codecs.FLAKE</AssemblyName>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
<DebugSymbols>true</DebugSymbols>
<DebugType>full</DebugType>
<Optimize>false</Optimize>
<OutputPath>bin\Debug\</OutputPath>
<DefineConstants>DEBUG;TRACE</DefineConstants>
<ErrorReport>prompt</ErrorReport>
<WarningLevel>4</WarningLevel>
<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
<DebugType>pdbonly</DebugType>
<Optimize>true</Optimize>
<OutputPath>bin\Release\</OutputPath>
<DefineConstants>TRACE</DefineConstants>
<ErrorReport>prompt</ErrorReport>
<WarningLevel>4</WarningLevel>
<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
</PropertyGroup>
<ItemGroup>
<Reference Include="System" />
<Reference Include="System.Data" />
<Reference Include="System.Xml" />
</ItemGroup>
<ItemGroup>
<Compile Include="BitReader.cs" />
<Compile Include="BitWriter.cs" />
<Compile Include="Flake.cs" />
<Compile Include="FlakeReader.cs" />
<Compile Include="FlakeWriter.cs" />
<Compile Include="lpc.cs" />
<Compile Include="Properties\AssemblyInfo.cs" />
</ItemGroup>
<ItemGroup>
<ProjectReference Include="..\CUETools.Codecs\CUETools.Codecs.csproj">
<Project>{6458A13A-30EF-45A9-9D58-E5031B17BEE2}</Project>
<Name>CUETools.Codecs</Name>
</ProjectReference>
</ItemGroup>
<Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
<!-- To modify your build process, add your task inside one of the targets below and uncomment it.
Other similar extension points exist, see Microsoft.Common.targets.
<Target Name="BeforeBuild">
</Target>
<Target Name="AfterBuild">
</Target>
-->
</Project>

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using System;
using System.Collections.Generic;
using System.Text;
namespace CUETools.Codecs.FLAKE
{
public class Flake
{
public const int MAX_BLOCKSIZE = 65535;
public const int MAX_RICE_PARAM = 14;
public const int MAX_PARTITION_ORDER = 8;
public const int MAX_PARTITIONS = 1 << MAX_PARTITION_ORDER;
public static int log2i(int v)
{
return log2i((uint)v);
}
public static int log2i(uint v)
{
int i;
int n = 0;
if (0 != (v & 0xffff0000)) { v >>= 16; n += 16; }
if (0 != (v & 0xff00)) { v >>= 8; n += 8; }
for (i = 2; i < 256; i <<= 1)
{
if (v >= i) n++;
else break;
}
return n;
}
public static PredictionType LookupPredictionType(string name)
{
switch (name)
{
case "fixed": return PredictionType.Fixed;
case "levinson": return PredictionType.Levinson;
case "search" : return PredictionType.Search;
}
return (PredictionType)Int32.Parse(name);
}
public static StereoMethod LookupStereoMethod(string name)
{
switch (name)
{
case "independent": return StereoMethod.Independent;
case "estimate": return StereoMethod.Estimate;
case "estimate2": return StereoMethod.Estimate2;
case "estimate3": return StereoMethod.Estimate3;
case "estimate4": return StereoMethod.Estimate4;
case "estimate5": return StereoMethod.Estimate5;
case "search": return StereoMethod.Search;
}
return (StereoMethod)Int32.Parse(name);
}
public static OrderMethod LookupOrderMethod(string name)
{
switch (name)
{
case "estimate": return OrderMethod.Estimate;
case "logfast": return OrderMethod.LogFast;
case "logsearch": return OrderMethod.LogSearch;
case "estsearch": return OrderMethod.EstSearch;
case "search": return OrderMethod.Search;
}
return (OrderMethod)Int32.Parse(name);
}
public static WindowFunction LookupWindowFunction(string name)
{
string[] parts = name.Split(',');
WindowFunction res = (WindowFunction)0;
foreach (string part in parts)
{
switch (part)
{
case "welch": res |= WindowFunction.Welch; break;
case "tukey": res |= WindowFunction.Tukey; break;
case "hann": res |= WindowFunction.Hann; break;
case "flattop": res |= WindowFunction.Flattop; break;
default: res |= (WindowFunction)Int32.Parse(name); break;
}
}
return res;
}
unsafe public static bool memcmp(int* res, int* smp, int n)
{
for (int i = n; i > 0; i--)
if (*(res++) != *(smp++))
return true;
return false;
}
unsafe public static void memcpy(int* res, int* smp, int n)
{
for (int i = n; i > 0; i--)
*(res++) = *(smp++);
}
unsafe public static void memset(int* res, int smp, int n)
{
for (int i = n; i > 0; i--)
*(res++) = smp;
}
}
unsafe struct RiceContext
{
public int porder; /* partition order */
public fixed uint rparams[Flake.MAX_PARTITIONS]; /* Rice parameters */
public fixed int esc_bps[Flake.MAX_PARTITIONS]; /* bps if using escape code */
};
unsafe struct FlacSubframe
{
public SubframeType type;
public int order;
public uint obits;
public uint wbits;
public int cbits;
public int shift;
public fixed int coefs[lpc.MAX_LPC_ORDER];
public int* samples;
public int* residual;
public RiceContext rc;
public uint size;
public fixed uint done_lpcs[lpc.MAX_LPC_WINDOWS];
public uint done_fixed;
public int window;
};
unsafe struct FlacFrame
{
public int blocksize;
public int bs_code0, bs_code1;
public ChannelMode ch_mode;
public int ch_order0, ch_order1;
public byte crc8;
public FlacSubframe* subframes;
public uint frame_count;
public FlacSubframe current;
}
public enum OrderMethod
{
Max = 0,
Estimate = 1,
LogFast = 2,
LogSearch = 3,
EstSearch = 4,
Search = 5
}
/// <summary>
/// Type of linear prediction
/// </summary>
public enum PredictionType
{
/// <summary>
/// verbatim
/// </summary>
None = 0,
/// <summary>
/// Fixed only
/// </summary>
Fixed = 1,
/// <summary>
/// Levinson-Durbin recursion
/// </summary>
Levinson = 2,
/// <summary>
/// Exhaustive search
/// </summary>
Search = 3,
/// <summary>
/// Internal; Use prediction type from previous estimation
/// </summary>
Estimated = 4
}
public enum StereoMethod
{
Independent = 0,
Estimate = 1,
Estimate2 = 2,
Estimate3 = 3,
Estimate4 = 4,
Estimate5 = 5,
Search = 9
}
public enum SubframeType
{
Constant = 0,
Verbatim = 1,
Fixed = 8,
LPC = 32
};
public enum ChannelMode
{
NotStereo = 0,
LeftRight = 1,
LeftSide = 8,
RightSide = 9,
MidSide = 10
}
public enum WindowFunction
{
Welch = 1,
Tukey = 2,
Hann = 4,
Flattop = 8
}
public enum MetadataType
{
/// <summary>
/// <A HREF="../format.html#metadata_block_streaminfo">STREAMINFO</A> block
/// </summary>
FLAC__METADATA_TYPE_STREAMINFO = 0,
/// <summary>
/// <A HREF="../format.html#metadata_block_padding">PADDING</A> block
/// </summary>
FLAC__METADATA_TYPE_PADDING = 1,
FLAC__METADATA_TYPE_APPLICATION = 2,
/**< <A HREF="../format.html#metadata_block_application">APPLICATION</A> block */
FLAC__METADATA_TYPE_SEEKTABLE = 3,
/**< <A HREF="../format.html#metadata_block_seektable">SEEKTABLE</A> block */
FLAC__METADATA_TYPE_VORBIS_COMMENT = 4,
/**< <A HREF="../format.html#metadata_block_vorbis_comment">VORBISCOMMENT</A> block (a.k.a. FLAC tags) */
FLAC__METADATA_TYPE_CUESHEET = 5,
/**< <A HREF="../format.html#metadata_block_cuesheet">CUESHEET</A> block */
FLAC__METADATA_TYPE_PICTURE = 6,
/**< <A HREF="../format.html#metadata_block_picture">PICTURE</A> block */
FLAC__METADATA_TYPE_UNDEFINED = 7
/**< marker to denote beginning of undefined type range; this number will increase as new metadata types are added */
};
}

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using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
namespace CUETools.Codecs.FLAKE
{
public class FlakeReader: IAudioSource
{
int[] flac_blocksizes;
int[] flac_bitdepths;
int[] samplesBuffer;
int[] residualBuffer;
byte[] _framesBuffer;
int _framesBufferLength = 0, _framesBufferOffset = 0;
Crc8 crc8;
Crc16 crc16;
int channels;
uint bits_per_sample;
int sample_rate = 44100;
uint min_block_size = 0;
uint max_block_size = 0;
uint min_frame_size = 0;
uint max_frame_size = 0;
uint _samplesInBuffer, _samplesBufferOffset;
ulong _sampleCount = 0;
ulong _sampleOffset = 0;
string _path;
Stream _IO;
public int[] Samples
{
get
{
return samplesBuffer;
}
}
public FlakeReader(string path, Stream IO)
{
_path = path;
_IO = IO != null ? IO : new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);
flac_bitdepths = new int[8] { 0, 8, 12, 0, 16, 20, 24, 0 };
flac_blocksizes = new int[15] { 0, 192, 576, 1152, 2304, 4608, 0, 0, 256, 512, 1024, 2048, 4096, 8192, 16384 };
crc8 = new Crc8();
crc16 = new Crc16();
_framesBuffer = new byte[0x10000];
decode_metadata();
//max_frame_size = 16 + ((Flake.MAX_BLOCKSIZE * (int)(bits_per_sample * channels + 1) + 7) >> 3);
if (max_frame_size * 2 > _framesBuffer.Length)
{
byte[] temp = _framesBuffer;
_framesBuffer = new byte[max_frame_size * 2];
if (_framesBufferLength > 0)
Array.Copy(temp, _framesBufferOffset, _framesBuffer, 0, _framesBufferLength);
_framesBufferOffset = 0;
}
_samplesInBuffer = 0;
if (bits_per_sample != 16 || channels != 2 || sample_rate != 44100)
throw new Exception("invalid flac file");
samplesBuffer = new int[Flake.MAX_BLOCKSIZE * channels];
residualBuffer = new int[Flake.MAX_BLOCKSIZE * channels];
}
public FlakeReader(int _channels, uint _bits_per_sample)
{
flac_bitdepths = new int[8] { 0, 8, 12, 0, 16, 20, 24, 0 };
flac_blocksizes = new int[15] { 0, 192, 576, 1152, 2304, 4608, 0, 0, 256, 512, 1024, 2048, 4096, 8192, 16384 };
crc8 = new Crc8();
crc16 = new Crc16();
channels = _channels;
bits_per_sample = _bits_per_sample;
samplesBuffer = new int[Flake.MAX_BLOCKSIZE * channels];
residualBuffer = new int[Flake.MAX_BLOCKSIZE * channels];
}
public void Close()
{
_IO.Close();
}
public int[,] Read(int[,] buff)
{
return AudioSamples.Read(this, buff);
}
public ulong Length
{
get
{
return _sampleCount;
}
}
public ulong Remaining
{
get
{
return _sampleCount - _sampleOffset + _samplesInBuffer;
}
}
public ulong Position
{
get
{
return _sampleOffset - _samplesInBuffer;
}
set
{
throw new Exception("seeking not yet supported");
}
}
public int BitsPerSample
{
get
{
return (int)bits_per_sample;
}
}
public int ChannelCount
{
get
{
return channels;
}
}
public int SampleRate
{
get
{
return sample_rate;
}
}
public string Path
{
get
{
return _path;
}
}
void interlace(int [,] buff, int offset, int count)
{
for (int ch = 0; ch < channels ; ch++)
for (int i = 0; i < count; i++)
buff[offset + i, ch] = samplesBuffer[_samplesBufferOffset + i + ch * Flake.MAX_BLOCKSIZE];
}
public uint Read(int[,] buff, uint sampleCount)
{
uint offset = 0;
while (_samplesInBuffer < sampleCount)
{
if (_samplesInBuffer > 0)
{
interlace(buff, (int)offset, (int)_samplesInBuffer);
sampleCount -= (uint)_samplesInBuffer;
offset += _samplesInBuffer;
_samplesInBuffer = 0;
_samplesBufferOffset = 0;
}
fill_frames_buffer();
if (_framesBufferLength == 0)
return offset;
int bytesDecoded = DecodeFrame(_framesBuffer, _framesBufferOffset, _framesBufferLength);
_framesBufferLength -= bytesDecoded;
_framesBufferOffset += bytesDecoded;
_samplesInBuffer -= _samplesBufferOffset; // can be set by Seek, otherwise zero
_sampleOffset += _samplesInBuffer;
}
interlace(buff, (int)offset, (int)sampleCount);
_samplesInBuffer -= sampleCount;
_samplesBufferOffset += sampleCount;
if (_samplesInBuffer == 0)
_samplesBufferOffset = 0;
return (uint)offset + sampleCount;
}
void fill_frames_buffer()
{
if (_framesBufferLength == 0)
_framesBufferOffset = 0;
else if (_framesBufferLength < _framesBuffer.Length / 2 && _framesBufferOffset >= _framesBuffer.Length / 2)
{
Array.Copy(_framesBuffer, _framesBufferOffset, _framesBuffer, 0, _framesBufferLength);
_framesBufferOffset = 0;
}
while (_framesBufferLength < _framesBuffer.Length / 2)
{
int read = _IO.Read(_framesBuffer, _framesBufferOffset + _framesBufferLength, _framesBuffer.Length - _framesBufferOffset - _framesBufferLength);
_framesBufferLength += read;
if (read == 0)
break;
}
}
unsafe void decode_frame_header(BitReader bitreader, FlacFrame* frame)
{
int header_start = bitreader.Position;
if (bitreader.readbits(16) != 0xFFF8)
throw new Exception("invalid frame");
frame->bs_code0 = (int) bitreader.readbits(4);
uint sr_code0 = bitreader.readbits(4);
frame->ch_mode = (ChannelMode)bitreader.readbits(4);
uint bps_code = bitreader.readbits(3);
if (flac_bitdepths[bps_code] != bits_per_sample)
throw new Exception("unsupported bps coding");
uint t1 = bitreader.readbit(); // == 0?????
if (t1 != 0)
throw new Exception("unsupported frame coding");
frame->frame_count = bitreader.read_utf8();
// custom block size
if (frame->bs_code0 == 6)
{
frame->bs_code1 = (int)bitreader.readbits(8);
frame->blocksize = frame->bs_code1 + 1;
}
else if (frame->bs_code0 == 7)
{
frame->bs_code1 = (int)bitreader.readbits(16);
frame->blocksize = frame->bs_code1 + 1;
}
else
frame->blocksize = flac_blocksizes[frame->bs_code0];
// custom sample rate
if (sr_code0 < 4 || sr_code0 > 11)
{
// sr_code0 == 12 -> sr == bitreader.readbits(8) * 1000;
// sr_code0 == 13 -> sr == bitreader.readbits(16);
// sr_code0 == 14 -> sr == bitreader.readbits(16) * 10;
throw new Exception("invalid sample rate mode");
}
int frame_channels = (int)frame->ch_mode + 1;
if (frame_channels > 11)
throw new Exception("invalid channel mode");
if (frame_channels == 2 || frame_channels > 8) // Mid/Left/Right Side Stereo
frame_channels = 2;
else
frame->ch_mode = ChannelMode.NotStereo;
if (frame_channels != channels)
throw new Exception("invalid channel mode");
// CRC-8 of frame header
byte crc = crc8.ComputeChecksum(bitreader.Buffer, header_start, bitreader.Position - header_start);
frame->crc8 = (byte)bitreader.readbits(8);
if (frame->crc8 != crc)
throw new Exception("header crc mismatch");
}
unsafe void decode_subframe_constant(BitReader bitreader, FlacFrame* frame, int ch)
{
int obits = (int)frame->subframes[ch].obits;
frame->subframes[ch].residual[0] = bitreader.readbits_signed(obits);
}
unsafe void decode_subframe_verbatim(BitReader bitreader, FlacFrame* frame, int ch)
{
int obits = (int)frame->subframes[ch].obits;
for (int i = 0; i < frame->blocksize; i++)
frame->subframes[ch].residual[i] = bitreader.readbits_signed(obits);
}
unsafe void decode_residual(BitReader bitreader, FlacFrame* frame, int ch)
{
// rice-encoded block
uint coding_method = bitreader.readbits(2); // ????? == 0
if (coding_method != 0) // if 1, then parameter length == 5 bits instead of 4
throw new Exception("unsupported residual coding");
// partition order
frame->subframes[ch].rc.porder = (int)bitreader.readbits(4);
if (frame->subframes[ch].rc.porder > 8)
throw new Exception("invalid partition order");
int psize = frame->blocksize >> frame->subframes[ch].rc.porder;
int res_cnt = psize - frame->subframes[ch].order;
// residual
int j = frame->subframes[ch].order;
int* r = frame->subframes[ch].residual + j;
for (int p = 0; p < (1 << frame->subframes[ch].rc.porder); p++)
{
uint k = frame->subframes[ch].rc.rparams[p] = bitreader.readbits(4);
if (p == 1) res_cnt = psize;
int n = Math.Min(res_cnt, frame->blocksize - j);
if (k == 0)
for (int i = n; i > 0; i--)
*(r++) = bitreader.read_unary_signed();
else if (k <= 8)
for (int i = n; i > 0; i--)
*(r++) = bitreader.read_rice_signed8((int)k);
else
for (int i = n; i > 0; i--)
*(r++) = bitreader.read_rice_signed((int)k);
j += n;
}
}
unsafe void decode_subframe_fixed(BitReader bitreader, FlacFrame* frame, int ch)
{
// warm-up samples
int obits = (int)frame->subframes[ch].obits;
for (int i = 0; i < frame->subframes[ch].order; i++)
frame->subframes[ch].residual[i] = bitreader.readbits_signed(obits);
// residual
decode_residual(bitreader, frame, ch);
}
unsafe void decode_subframe_lpc(BitReader bitreader, FlacFrame* frame, int ch)
{
// warm-up samples
int obits = (int)frame->subframes[ch].obits;
for (int i = 0; i < frame->subframes[ch].order; i++)
frame->subframes[ch].residual[i] = bitreader.readbits_signed(obits);
// LPC coefficients
frame->subframes[ch].cbits = (int)bitreader.readbits(4) + 1; // lpc_precision
frame->subframes[ch].shift = bitreader.readbits_signed(5);
for (int i = 0; i < frame->subframes[ch].order; i++)
frame->subframes[ch].coefs[i] = bitreader.readbits_signed(frame->subframes[ch].cbits);
// residual
decode_residual(bitreader, frame, ch);
}
unsafe void decode_subframes(BitReader bitreader, FlacFrame* frame)
{
fixed (int *r = residualBuffer, s = samplesBuffer)
for (int ch = 0; ch < channels; ch++)
{
// subframe header
uint t1 = bitreader.readbit(); // ?????? == 0
if (t1 != 0)
throw new Exception("unsupported subframe coding");
int type_code = (int)bitreader.readbits(6);
frame->subframes[ch].wbits = bitreader.readbit();
if (frame->subframes[ch].wbits != 0)
frame->subframes[ch].wbits += bitreader.read_unary();
frame->subframes[ch].obits = bits_per_sample - frame->subframes[ch].wbits;
switch (frame->ch_mode)
{
case ChannelMode.MidSide: frame->subframes[ch].obits += (uint)ch; break;
case ChannelMode.LeftSide: frame->subframes[ch].obits += (uint)ch; break;
case ChannelMode.RightSide: frame->subframes[ch].obits += 1 - (uint)ch; break;
}
frame->subframes[ch].type = (SubframeType)type_code;
frame->subframes[ch].order = 0;
if ((type_code & (uint)SubframeType.LPC) != 0)
{
frame->subframes[ch].order = (type_code - (int)SubframeType.LPC) + 1;
frame->subframes[ch].type = SubframeType.LPC;
}
else if ((type_code & (uint)SubframeType.Fixed) != 0)
{
frame->subframes[ch].order = (type_code - (int)SubframeType.Fixed);
frame->subframes[ch].type = SubframeType.Fixed;
}
frame->subframes[ch].residual = r + ch * Flake.MAX_BLOCKSIZE;
frame->subframes[ch].samples = s + ch * Flake.MAX_BLOCKSIZE;
// subframe
switch (frame->subframes[ch].type)
{
case SubframeType.Constant:
decode_subframe_constant(bitreader, frame, ch);
break;
case SubframeType.Verbatim:
decode_subframe_verbatim(bitreader, frame, ch);
break;
case SubframeType.Fixed:
decode_subframe_fixed(bitreader, frame, ch);
break;
case SubframeType.LPC:
decode_subframe_lpc(bitreader, frame, ch);
break;
default:
throw new Exception("invalid subframe type");
}
}
}
unsafe void restore_samples_fixed(FlacFrame* frame, int ch)
{
FlacSubframe* sub = frame->subframes + ch;
Flake.memcpy(sub->samples, sub->residual, sub->order);
int* data = sub->samples + sub->order;
int* residual = sub->residual + sub->order;
int data_len = frame->blocksize - sub->order;
switch (sub->order)
{
case 0:
Flake.memcpy(data, residual, data_len);
break;
case 1:
for (int i = 0; i < data_len; i++)
data[i] = residual[i] + data[i - 1];
break;
case 2:
for (int i = 0; i < data_len; i++)
data[i] = residual[i] + (data[i - 1] << 1) - data[i - 2];
break;
case 3:
for (int i = 0; i < data_len; i++)
data[i] = residual[i] + (((data[i - 1] - data[i - 2]) << 1) + (data[i - 1] - data[i - 2])) + data[i - 3];
break;
case 4:
for (int i = 0; i < data_len; i++)
data[i] = residual[i] + ((data[i - 1] + data[i - 3]) << 2) - ((data[i - 2] << 2) + (data[i - 2] << 1)) - data[i - 4];
break;
}
}
unsafe void restore_samples_lpc(FlacFrame* frame, int ch)
{
FlacSubframe* sub = frame->subframes + ch;
if ((ulong)sub->order * ((1UL << (int)sub->obits) - 1) * ((1U << sub->cbits) - 1) >= (1UL << 32))
lpc.decode_residual_long(sub->residual, sub->samples, frame->blocksize, sub->order, sub->coefs, sub->shift);
else
lpc.decode_residual(sub->residual, sub->samples, frame->blocksize, sub->order, sub->coefs, sub->shift);
}
unsafe void restore_samples(FlacFrame* frame)
{
for (int ch = 0; ch < channels; ch++)
{
switch (frame->subframes[ch].type)
{
case SubframeType.Constant:
Flake.memset(frame->subframes[ch].samples, frame->subframes[ch].residual[0], frame->blocksize);
break;
case SubframeType.Verbatim:
Flake.memcpy(frame->subframes[ch].samples, frame->subframes[ch].residual, frame->blocksize);
break;
case SubframeType.Fixed:
restore_samples_fixed(frame, ch);
break;
case SubframeType.LPC:
restore_samples_lpc(frame, ch);
break;
}
if (frame->subframes[ch].wbits != 0)
{
int x = (int) frame->subframes[ch].wbits;
for (int i = 0; i < frame->blocksize; i++)
frame->subframes[ch].samples[i] <<= x;
}
}
switch (frame->ch_mode)
{
case ChannelMode.NotStereo:
break;
case ChannelMode.LeftRight:
break;
case ChannelMode.MidSide:
for (int i = 0; i < frame->blocksize; i++)
{
int mid = frame->subframes[0].samples[i];
int side = frame->subframes[1].samples[i];
mid <<= 1;
mid |= (side & 1); /* i.e. if 'side' is odd... */
frame->subframes[0].samples[i] = (mid + side) >> 1;
frame->subframes[1].samples[i] = (mid - side) >> 1;
}
break;
case ChannelMode.LeftSide:
for (int i = 0; i < frame->blocksize; i++)
frame->subframes[1].samples[i] = frame->subframes[0].samples[i] - frame->subframes[1].samples[i];
break;
case ChannelMode.RightSide:
for (int i = 0; i < frame->blocksize; i++)
frame->subframes[0].samples[i] += frame->subframes[1].samples[i];
break;
}
}
public unsafe int DecodeFrame(byte[] buffer, int pos, int len)
{
BitReader bitreader = new BitReader(buffer, pos, len);
FlacFrame frame;
FlacSubframe* subframes = stackalloc FlacSubframe[channels];
frame.subframes = subframes;
decode_frame_header(bitreader, &frame);
decode_subframes(bitreader, &frame);
bitreader.flush();
ushort crc = crc16.ComputeChecksum(bitreader.Buffer, pos, bitreader.Position - pos);
if (crc != bitreader.readbits(16))
throw new Exception("frame crc mismatch");
restore_samples(&frame);
restore_samples(&frame);
_samplesInBuffer = (uint)frame.blocksize;
return bitreader.Position - pos;
}
bool skip_bytes(int bytes)
{
for (int j = 0; j < bytes; j++)
if (0 == _IO.Read(_framesBuffer, 0, 1))
return false;
return true;
}
void decode_metadata()
{
byte x;
int i, id;
bool first = true;
byte[] FLAC__STREAM_SYNC_STRING = new byte[] { (byte)'f', (byte)'L', (byte)'a', (byte)'C' };
byte[] ID3V2_TAG_ = new byte[] { (byte)'I', (byte)'D', (byte)'3' };
for (i = id = 0; i < 4; )
{
if (_IO.Read(_framesBuffer, 0, 1) == 0)
throw new Exception("FLAC stream not found");
x = _framesBuffer[0];
if (x == FLAC__STREAM_SYNC_STRING[i])
{
first = true;
i++;
id = 0;
continue;
}
if (id < 3 && x == ID3V2_TAG_[id])
{
id++;
i = 0;
if (id == 3)
{
if (!skip_bytes(3))
throw new Exception("FLAC stream not found");
int skip = 0;
for (int j = 0; j < 4; j++)
{
if (0 == _IO.Read(_framesBuffer, 0, 1))
throw new Exception("FLAC stream not found");
skip <<= 7;
skip |= ((int)_framesBuffer[0] & 0x7f);
}
if (!skip_bytes(skip))
throw new Exception("FLAC stream not found");
}
continue;
}
id = 0;
if (x == 0xff) /* MAGIC NUMBER for the first 8 frame sync bits */
{
do
{
if (_IO.Read(_framesBuffer, 0, 1) == 0)
throw new Exception("FLAC stream not found");
x = _framesBuffer[0];
} while (x == 0xff);
if (x >> 2 == 0x3e) /* MAGIC NUMBER for the last 6 sync bits */
{
//_IO.Position -= 2;
// state = frame
throw new Exception("headerless file unsupported");
}
}
throw new Exception("FLAC stream not found");
}
do
{
long pos = _IO.Position;
fill_frames_buffer();
BitReader bitreader = new BitReader(_framesBuffer, _framesBufferOffset, _framesBufferLength - _framesBufferOffset);
bool is_last = bitreader.readbit() != 0;
MetadataType type = (MetadataType)bitreader.readbits(7);
int len = (int)bitreader.readbits(24);
if (type == MetadataType.FLAC__METADATA_TYPE_STREAMINFO)
{
const int FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN = 16; /* bits */
const int FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN = 16; /* bits */
const int FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN = 24; /* bits */
const int FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN = 24; /* bits */
const int FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN = 20; /* bits */
const int FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN = 3; /* bits */
const int FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN = 5; /* bits */
const int FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN = 36; /* bits */
const int FLAC__STREAM_METADATA_STREAMINFO_MD5SUM_LEN = 128; /* bits */
min_block_size = bitreader.readbits(FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN);
max_block_size = bitreader.readbits(FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN);
min_frame_size = bitreader.readbits(FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN);
max_frame_size = bitreader.readbits(FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN);
sample_rate = (int) bitreader.readbits(FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN);
channels = 1 + (int) bitreader.readbits(FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN);
bits_per_sample = 1 + bitreader.readbits(FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN);
_sampleCount = (((ulong)bitreader.readbits(4)) << 4) + (ulong)bitreader.readbits(32);
bitreader.skipbits(FLAC__STREAM_METADATA_STREAMINFO_MD5SUM_LEN);
}
if (_framesBufferLength < 4 + len)
{
_IO.Position = pos + 4 + len;
_framesBufferLength = 0;
}
else
{
_framesBufferLength -= 4 + len;
_framesBufferOffset += 4 + len;
}
if (is_last)
break;
} while (true);
}
}
}

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@@ -0,0 +1,35 @@
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
// General Information about an assembly is controlled through the following
// set of attributes. Change these attribute values to modify the information
// associated with an assembly.
[assembly: AssemblyTitle("CUETools.Codecs.FLAKE")]
[assembly: AssemblyDescription("")]
[assembly: AssemblyConfiguration("")]
[assembly: AssemblyCompany("Microsoft")]
[assembly: AssemblyProduct("CUETools.Codecs.FLAKE")]
[assembly: AssemblyCopyright("Copyright © Microsoft 2009")]
[assembly: AssemblyTrademark("")]
[assembly: AssemblyCulture("")]
// Setting ComVisible to false makes the types in this assembly not visible
// to COM components. If you need to access a type in this assembly from
// COM, set the ComVisible attribute to true on that type.
[assembly: ComVisible(false)]
// The following GUID is for the ID of the typelib if this project is exposed to COM
[assembly: Guid("af385bb5-1d2e-409b-97db-b96d9ed491a0")]
// Version information for an assembly consists of the following four values:
//
// Major Version
// Minor Version
// Build Number
// Revision
//
// You can specify all the values or you can default the Revision and Build Numbers
// by using the '*' as shown below:
[assembly: AssemblyVersion("1.0.0.0")]
[assembly: AssemblyFileVersion("1.0.0.0")]

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@@ -0,0 +1,650 @@
using System;
using System.Collections.Generic;
using System.Text;
namespace CUETools.Codecs.FLAKE
{
class lpc
{
public const int MAX_LPC_ORDER = 32;
public const int MAX_LPC_WINDOWS = 4;
/**
* Apply Welch window function to audio block
*/
static unsafe void
apply_welch_window(/*const*/int* data, uint len, double* w_data)
{
double c = (2.0 / (len - 1.0)) - 1.0;
for (uint i = 0; i < (len >> 1); i++)
{
double w = 1.0 - ((c - i) * (c - i));
w_data[i] = data[i] * w;
w_data[len - 1 - i] = data[len - 1 - i] * w;
}
}
/**
* Calculates autocorrelation data from audio samples
* A Welch window function is applied before calculation.
*/
static unsafe void
compute_autocorr(/*const*/ int* data, uint len, uint lag, double* autoc, double* window)
{
double* data1 = stackalloc double[(int)len + 16];
uint i, j;
double temp, temp2;
if (window == null)
apply_welch_window(data, len, data1);
else
{
for (i = 0; i < len; i++)
data1[i] = data[i] * window[i];
}
data1[len] = 0;
for (i = 0; i <= lag; ++i)
{
temp = 1.0;
temp2 = 1.0;
for (j = 0; j <= lag - i; ++j)
temp += data1[j + i] * data1[j];
double* finish = data1 + len - i;
for (double* pdata = data1 + lag + 1 - i; pdata < finish; pdata += 2)
{
temp += pdata[i] * pdata[0];
temp2 += pdata[i + 1] * pdata[1];
}
autoc[i] = temp + temp2;
}
//int sample, coeff;
//for (coeff = 0; coeff <= lag; coeff++)
// autoc[coeff] = 0.0;
//int data_len = (int)len;
//int limit = data_len - (int)lag - 1;
//for (sample = 0; sample <= limit; sample++)
//{
// double d = data1[sample];
// for (coeff = 0; coeff <= lag; coeff++)
// autoc[coeff] += d * data1[sample + coeff];
//}
//for (; sample < data_len; sample++)
//{
// double d = data1[sample];
// for (coeff = 0; coeff < data_len - sample; coeff++)
// autoc[coeff] += d * data1[sample + coeff];
//}
}
/**
* Levinson-Durbin recursion.
* Produces LPC coefficients from autocorrelation data.
*/
static unsafe void
compute_lpc_coefs(/*const*/ double* autoc, uint max_order, double* reff,
double* lpc/*[][MAX_LPC_ORDER]*/)
{
double* lpc_tmp = stackalloc double[MAX_LPC_ORDER];
int i, j, i2;
double r, err, tmp;
if (max_order > MAX_LPC_ORDER)
throw new Exception("wierd");
for (i = 0; i < max_order; i++)
lpc_tmp[i] = 0;
err = 1.0;
if (autoc != null)
err = autoc[0];
for (i = 0; i < max_order; i++)
{
if (reff != null)
{
r = reff[i];
}
else
{
r = -autoc[i + 1];
for (j = 0; j < i; j++)
{
r -= lpc_tmp[j] * autoc[i - j];
}
r /= err;
err *= 1.0 - (r * r);
}
i2 = (i >> 1);
lpc_tmp[i] = r;
for (j = 0; j < i2; j++)
{
tmp = lpc_tmp[j];
lpc_tmp[j] += r * lpc_tmp[i - 1 - j];
lpc_tmp[i - 1 - j] += r * tmp;
}
if (0 != (i & 1))
{
lpc_tmp[j] += lpc_tmp[j] * r;
}
for (j = 0; j <= i; j++)
{
lpc[i * MAX_LPC_ORDER + j] = -lpc_tmp[j];
}
}
}
/**
* Compute LPC coefs for Flake.OrderMethod._EST
* Faster LPC coeff computation by first calculating the reflection coefficients
* using Schur recursion. That allows for estimating the optimal order before
* running Levinson recursion.
*/
static unsafe uint
compute_lpc_coefs_est(/*const*/ double* autoc, uint max_order,
double* lpc/*[][MAX_LPC_ORDER]*/)
{
double* gen0 = stackalloc double[MAX_LPC_ORDER];
double* gen1 = stackalloc double[MAX_LPC_ORDER];
double* reff = stackalloc double[MAX_LPC_ORDER];
// Schur recursion
for (uint i = 0; i < max_order; i++)
gen0[i] = gen1[i] = autoc[i + 1];
double error = autoc[0];
reff[0] = -gen1[0] / error;
error += gen1[0] * reff[0];
for (uint i = 1; i < max_order; i++)
{
for (uint j = 0; j < max_order - i; j++)
{
gen1[j] = gen1[j + 1] + reff[i - 1] * gen0[j];
gen0[j] = gen1[j + 1] * reff[i - 1] + gen0[j];
}
reff[i] = -gen1[0] / error;
error += gen1[0] * reff[i];
}
// Estimate optimal order using reflection coefficients
uint order_est = 1;
for (int i = (int)max_order - 1; i >= 0; i--)
{
if (Math.Abs(reff[i]) > 0.10)
{
order_est = (uint)i + 1;
break;
}
}
// Levinson recursion
compute_lpc_coefs(null, order_est, reff, lpc);
return order_est;
}
/**
* Quantize LPC coefficients
*/
public static unsafe void
quantize_lpc_coefs(double* lpc_in, int order, uint precision, int* lpc_out,
out int shift)
{
int i;
double d, cmax, error;
int qmax;
int sh, q;
// define maximum levels
qmax = (1 << ((int)precision - 1)) - 1;
// find maximum coefficient value
cmax = 0.0;
for (i = 0; i < order; i++)
{
d = Math.Abs(lpc_in[i]);
if (d > cmax)
cmax = d;
}
// if maximum value quantizes to zero, return all zeros
if (cmax * (1 << 15) < 1.0)
{
shift = 0;
for (i = 0; i < order; i++)
lpc_out[i] = 0;
return;
}
// calculate level shift which scales max coeff to available bits
sh = 15;
while ((cmax * (1 << sh) > qmax) && (sh > 0))
{
sh--;
}
// since negative shift values are unsupported in decoder, scale down
// coefficients instead
if (sh == 0 && cmax > qmax)
{
double scale = ((double)qmax) / cmax;
for (i = 0; i < order; i++)
{
lpc_in[i] *= scale;
}
}
// output quantized coefficients and level shift
error = 0;
for (i = 0; i < order; i++)
{
error += lpc_in[i] * (1 << sh);
q = (int)(error + 0.5);
if (q <= -qmax) q = -qmax + 1;
if (q > qmax) q = qmax;
error -= q;
lpc_out[i] = q;
}
shift = sh;
}
/**
* Calculate LPC coefficients for multiple orders
*/
public static unsafe uint
calc_coefs(/*const*/ int* samples, uint blocksize, uint max_order, OrderMethod omethod, double* lpcs, double* window)
{
double* autoc = stackalloc double[MAX_LPC_ORDER + 1];
compute_autocorr(samples, blocksize, max_order + 1, autoc, window);
uint opt_order = max_order;
if (omethod == OrderMethod.Estimate || omethod == OrderMethod.EstSearch)
opt_order = compute_lpc_coefs_est(autoc, max_order, lpcs);
else
compute_lpc_coefs(autoc, max_order, null, lpcs);
return opt_order;
}
public static unsafe void
encode_residual(int* res, int* smp, int n, int order,
int* coefs, int shift)
{
for (int i = 0; i < order; i++)
res[i] = smp[i];
int* s = smp;
int* r = res + order;
int c0 = coefs[0];
int c1 = coefs[1];
switch (order)
{
case 1:
for (int i = n - order; i > 0; i--)
{
int pred = c0 * *(s++);
*(r++) = *s - (pred >> shift);
}
break;
case 2:
for (int i = n - order; i > 0; i--)
{
int pred = c1 * *(s++);
pred += c0 * *(s++);
*(r++) = *(s--) - (pred >> shift);
}
break;
case 3:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*(r++) = *s - (pred >> shift);
s -= 2;
}
break;
case 4:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*(r++) = *s - (pred >> shift);
s -= 3;
}
break;
case 5:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[4] * *(s++);
pred += coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*(r++) = *s - (pred >> shift);
s -= 4;
}
break;
case 6:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[5] * *(s++);
pred += coefs[4] * *(s++);
pred += coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*(r++) = *s - (pred >> shift);
s -= 5;
}
break;
case 7:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[6] * *(s++);
pred += coefs[5] * *(s++);
pred += coefs[4] * *(s++);
pred += coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*(r++) = *s - (pred >> shift);
s -= 6;
}
break;
case 8:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[7] * *(s++);
pred += coefs[6] * *(s++);
pred += coefs[5] * *(s++);
pred += coefs[4] * *(s++);
pred += coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*(r++) = *s - (pred >> shift);
s -= 7;
}
break;
default:
for (int i = order; i < n; i++)
{
s = smp + i - order;
int pred = 0;
int* co = coefs + order - 1;
int* c7 = coefs + 7;
while (co > c7)
pred += *(co--) * *(s++);
pred += coefs[7] * *(s++);
pred += coefs[6] * *(s++);
pred += coefs[5] * *(s++);
pred += coefs[4] * *(s++);
pred += coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*(r++) = *s - (pred >> shift);
}
break;
}
}
public static unsafe void
decode_residual(int* res, int* smp, int n, int order,
int* coefs, int shift)
{
for (int i = 0; i < order; i++)
smp[i] = res[i];
int* s = smp;
int* r = res + order;
int c0 = coefs[0];
int c1 = coefs[1];
switch (order)
{
case 1:
for (int i = n - order; i > 0; i--)
{
int pred = c0 * *(s++);
*s = *(r++) + (pred >> shift);
}
break;
case 2:
for (int i = n - order; i > 0; i--)
{
int pred = c1 * *(s++);
pred += c0 * *(s++);
*(s--) = *(r++) + (pred >> shift);
}
break;
case 3:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*s = *(r++) + (pred >> shift);
s -= 2;
}
break;
case 4:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*s = *(r++) + (pred >> shift);
s -= 3;
}
break;
case 5:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[4] * *(s++);
pred += coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*s = *(r++) + (pred >> shift);
s -= 4;
}
break;
case 6:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[5] * *(s++);
pred += coefs[4] * *(s++);
pred += coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*s = *(r++) + (pred >> shift);
s -= 5;
}
break;
case 7:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[6] * *(s++);
pred += coefs[5] * *(s++);
pred += coefs[4] * *(s++);
pred += coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*s = *(r++) + (pred >> shift);
s -= 6;
}
break;
case 8:
for (int i = n - order; i > 0; i--)
{
int pred = coefs[7] * *(s++);
pred += coefs[6] * *(s++);
pred += coefs[5] * *(s++);
pred += coefs[4] * *(s++);
pred += coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*s = *(r++) + (pred >> shift);
s -= 7;
}
break;
default:
for (int i = order; i < n; i++)
{
s = smp + i - order;
int pred = 0;
int* co = coefs + order - 1;
int* c7 = coefs + 7;
while (co > c7)
pred += *(co--) * *(s++);
pred += coefs[7] * *(s++);
pred += coefs[6] * *(s++);
pred += coefs[5] * *(s++);
pred += coefs[4] * *(s++);
pred += coefs[3] * *(s++);
pred += coefs[2] * *(s++);
pred += c1 * *(s++);
pred += c0 * *(s++);
*s = *(r++) + (pred >> shift);
}
break;
}
}
public static unsafe void
decode_residual_long(int* res, int* smp, int n, int order,
int* coefs, int shift)
{
for (int i = 0; i < order; i++)
smp[i] = res[i];
int* s = smp;
int* r = res + order;
int c0 = coefs[0];
int c1 = coefs[1];
switch (order)
{
case 1:
for (int i = n - order; i > 0; i--)
{
long pred = c0 * (long)*(s++);
*s = *(r++) + (int)(pred >> shift);
}
break;
case 2:
for (int i = n - order; i > 0; i--)
{
long pred = c1 * (long)*(s++);
pred += c0 * (long)*(s++);
*(s--) = *(r++) + (int)(pred >> shift);
}
break;
case 3:
for (int i = n - order; i > 0; i--)
{
long pred = coefs[2] * (long)*(s++);
pred += c1 * (long)*(s++);
pred += c0 * (long)*(s++);
*s = *(r++) + (int)(pred >> shift);
s -= 2;
}
break;
case 4:
for (int i = n - order; i > 0; i--)
{
long pred = coefs[3] * (long)*(s++);
pred += coefs[2] * (long)*(s++);
pred += c1 * (long)*(s++);
pred += c0 * (long)*(s++);
*s = *(r++) + (int)(pred >> shift);
s -= 3;
}
break;
case 5:
for (int i = n - order; i > 0; i--)
{
long pred = coefs[4] * (long)*(s++);
pred += coefs[3] * (long)*(s++);
pred += coefs[2] * (long)*(s++);
pred += c1 * (long)*(s++);
pred += c0 * (long)*(s++);
*s = *(r++) + (int)(pred >> shift);
s -= 4;
}
break;
case 6:
for (int i = n - order; i > 0; i--)
{
long pred = coefs[5] * (long)*(s++);
pred += coefs[4] * (long)*(s++);
pred += coefs[3] * (long)*(s++);
pred += coefs[2] * (long)*(s++);
pred += c1 * (long)*(s++);
pred += c0 * (long)*(s++);
*s = *(r++) + (int)(pred >> shift);
s -= 5;
}
break;
case 7:
for (int i = n - order; i > 0; i--)
{
long pred = coefs[6] * (long)*(s++);
pred += coefs[5] * (long)*(s++);
pred += coefs[4] * (long)*(s++);
pred += coefs[3] * (long)*(s++);
pred += coefs[2] * (long)*(s++);
pred += c1 * (long)*(s++);
pred += c0 * (long)*(s++);
*s = *(r++) + (int)(pred >> shift);
s -= 6;
}
break;
case 8:
for (int i = n - order; i > 0; i--)
{
long pred = coefs[7] * (long)*(s++);
pred += coefs[6] * (long)*(s++);
pred += coefs[5] * (long)*(s++);
pred += coefs[4] * (long)*(s++);
pred += coefs[3] * (long)*(s++);
pred += coefs[2] * (long)*(s++);
pred += c1 * (long)*(s++);
pred += c0 * (long)*(s++);
*s = *(r++) + (int)(pred >> shift);
s -= 7;
}
break;
default:
for (int i = order; i < n; i++)
{
s = smp + i - order;
long pred = 0;
int* co = coefs + order - 1;
int* c7 = coefs + 7;
while (co > c7)
pred += *(co--) * (long)*(s++);
pred += coefs[7] * (long)*(s++);
pred += coefs[6] * (long)*(s++);
pred += coefs[5] * (long)*(s++);
pred += coefs[4] * (long)*(s++);
pred += coefs[3] * (long)*(s++);
pred += coefs[2] * (long)*(s++);
pred += c1 * (long)*(s++);
pred += c0 * (long)*(s++);
*s = *(r++) + (int)(pred >> shift);
}
break;
}
}
}
}