internal static VorbisCodebook Init(VorbisStreamDecoder vorbis, DataPacket packet, int number)
{
var temp = new VorbisCodebook();
temp.BookNum = number;
temp.Init(packet);
return temp;
}
internal int DecodeScalar(DataPacket packet)
{
int bitCnt;
var bits = (int)packet.TryPeekBits(PrefixBitLength, out bitCnt);
if (bitCnt == 0) return -1;
// try to get the value from the prefix list...
var node = PrefixList[bits];
if (node != null)
{
packet.SkipBits(node.Length);
return node.Value;
}
// nope, not possible... run the tree
bits = (int)packet.TryPeekBits(MaxBits, out bitCnt);
node = PrefixOverflowTree;
do
{
if (node.Bits == (bits & node.Mask))
{
packet.SkipBits(node.Length);
return node.Value;
}
} while ((node = node.Next) != null);
return -1;
}
internal static VorbisMode Init(VorbisStreamDecoder vorbis, DataPacket packet)
{
var mode = new VorbisMode(vorbis);
mode.BlockFlag = packet.ReadBit();
mode.WindowType = (int)packet.ReadBits(16);
mode.TransformType = (int)packet.ReadBits(16);
var mapping = (int)packet.ReadBits(8);
if (mode.WindowType != 0 || mode.TransformType != 0 || mapping >= vorbis.Maps.Length) throw new InvalidDataException();
mode.Mapping = vorbis.Maps[mapping];
mode.BlockSize = mode.BlockFlag ? vorbis.Block1Size : vorbis.Block0Size;
// now pre-calc the window(s)...
if (mode.BlockFlag)
{
// long block
mode._windows = new float[4][];
mode._windows[0] = new float[vorbis.Block1Size];
mode._windows[1] = new float[vorbis.Block1Size];
mode._windows[2] = new float[vorbis.Block1Size];
mode._windows[3] = new float[vorbis.Block1Size];
}
else
{
// short block
mode._windows = new float[1][];
mode._windows[0] = new float[vorbis.Block0Size];
}
mode.CalcWindows();
return mode;
}
internal static VorbisTime Init(VorbisStreamDecoder vorbis, DataPacket packet)
{
var type = (int)packet.ReadBits(16);
VorbisTime time = null;
switch (type)
{
case 0: time = new Time0(vorbis); break;
}
if (time == null) throw new InvalidDataException();
time.Init(packet);
return time;
}
internal static VorbisMapping Init(VorbisStreamDecoder vorbis, DataPacket packet)
{
var type = (int)packet.ReadBits(16);
VorbisMapping mapping = null;
switch (type)
{
case 0: mapping = new Mapping0(vorbis); break;
}
if (mapping == null) throw new InvalidDataException();
mapping.Init(packet);
return mapping;
}
internal static VorbisFloor Init(VorbisStreamDecoder vorbis, DataPacket packet)
{
var type = (int)packet.ReadBits(16);
VorbisFloor floor = null;
switch (type)
{
case 0: floor = new Floor0(vorbis); break;
case 1: floor = new Floor1(vorbis); break;
}
if (floor == null) throw new InvalidDataException();
floor.Init(packet);
return floor;
}
internal static VorbisResidue Init(VorbisStreamDecoder vorbis, DataPacket packet)
{
var type = (int)packet.ReadBits(16);
VorbisResidue residue = null;
switch (type)
{
case 0: residue = new Residue0(vorbis); break;
case 1: residue = new Residue1(vorbis); break;
case 2: residue = new Residue2(vorbis); break;
}
if (residue == null) throw new InvalidDataException();
residue.Init(packet);
return residue;
}
internal abstract PacketData UnpackPacket(DataPacket packet, int blockSize, int channel);
void InitLookupTable(DataPacket packet)
{
MapType = (int)packet.ReadBits(4);
if (MapType == 0) return;
var minValue = Utils.ConvertFromVorbisFloat32(packet.ReadUInt32());
var deltaValue = Utils.ConvertFromVorbisFloat32(packet.ReadUInt32());
var valueBits = (int)packet.ReadBits(4) + 1;
var sequence_p = packet.ReadBit();
var lookupValueCount = Entries * Dimensions;
var lookupTable = new float[lookupValueCount];
if (MapType == 1)
{
lookupValueCount = lookup1_values();
}
var multiplicands = new uint[lookupValueCount];
for (var i = 0; i < lookupValueCount; i++)
{
multiplicands[i] = (uint)packet.ReadBits(valueBits);
}
// now that we have the initial data read in, calculate the entry tree
if (MapType == 1)
{
for (var idx = 0; idx < Entries; idx++)
{
var last = 0.0;
var idxDiv = 1;
for (var i = 0; i < Dimensions; i++)
{
var moff = (idx / idxDiv) % lookupValueCount;
var value = (float)multiplicands[moff] * deltaValue + minValue + last;
lookupTable[idx * Dimensions + i] = (float)value;
if (sequence_p) last = value;
idxDiv *= lookupValueCount;
}
}
}
else
{
for (var idx = 0; idx < Entries; idx++)
{
var last = 0.0;
var moff = idx * Dimensions;
for (var i = 0; i < Dimensions; i++)
{
var value = multiplicands[moff] * deltaValue + minValue + last;
lookupTable[idx * Dimensions + i] = (float)value;
if (sequence_p) last = value;
++moff;
}
}
}
LookupTable = lookupTable;
}
internal override PacketData UnpackPacket(DataPacket packet, int blockSize, int channel)
{
var data = _reusablePacketData[channel];
data.BlockSize = blockSize;
data.ForceEnergy = false;
data.ForceNoEnergy = false;
data.PostCount = 0;
Array.Clear(data.Posts, 0, 64);
// hoist ReadPosts to here since that's all we're doing...
if (packet.ReadBit())
{
var postCount = 2;
data.Posts[0] = (int)packet.ReadBits(_yBits);
data.Posts[1] = (int)packet.ReadBits(_yBits);
for (int i = 0; i < _partitionClass.Length; i++)
{
var clsNum = _partitionClass[i];
var cdim = _classDimensions[clsNum];
var cbits = _classSubclasses[clsNum];
var csub = (1 << cbits) - 1;
var cval = 0U;
if (cbits > 0)
{
if ((cval = (uint)_classMasterbooks[clsNum].DecodeScalar(packet)) == uint.MaxValue)
{
// we read a bad value... bail
postCount = 0;
break;
}
}
for (int j = 0; j < cdim; j++)
{
var book = _subclassBooks[clsNum][cval & csub];
cval >>= cbits;
if (book != null)
{
if ((data.Posts[postCount] = book.DecodeScalar(packet)) == -1)
{
// we read a bad value... bail
postCount = 0;
i = _partitionClass.Length;
break;
}
}
++postCount;
}
}
data.PostCount = postCount;
}
return data;
}
protected override void Init(DataPacket packet)
{
_partitionClass = new int[(int)packet.ReadBits(5)];
for (int i = 0; i < _partitionClass.Length; i++)
{
_partitionClass[i] = (int)packet.ReadBits(4);
}
var maximum_class = _partitionClass.Max();
_classDimensions = new int[maximum_class + 1];
_classSubclasses = new int[maximum_class + 1];
_classMasterbooks = new VorbisCodebook[maximum_class + 1];
_classMasterBookIndex = new int[maximum_class + 1];
_subclassBooks = new VorbisCodebook[maximum_class + 1][];
_subclassBookIndex = new int[maximum_class + 1][];
for (int i = 0; i <= maximum_class; i++)
{
_classDimensions[i] = (int)packet.ReadBits(3) + 1;
_classSubclasses[i] = (int)packet.ReadBits(2);
if (_classSubclasses[i] > 0)
{
_classMasterBookIndex[i] = (int)packet.ReadBits(8);
_classMasterbooks[i] = _vorbis.Books[_classMasterBookIndex[i]];
}
_subclassBooks[i] = new VorbisCodebook[1 << _classSubclasses[i]];
_subclassBookIndex[i] = new int[_subclassBooks[i].Length];
for (int j = 0; j < _subclassBooks[i].Length; j++)
{
var bookNum = (int)packet.ReadBits(8) - 1;
if (bookNum >= 0) _subclassBooks[i][j] = _vorbis.Books[bookNum];
_subclassBookIndex[i][j] = bookNum;
}
}
_multiplier = (int)packet.ReadBits(2);
_range = _rangeLookup[_multiplier];
_yBits = _yBitsLookup[_multiplier];
++_multiplier;
var rangeBits = (int)packet.ReadBits(4);
var xList = new List<int>();
xList.Add(0);
xList.Add(1 << rangeBits);
for (int i = 0; i < _partitionClass.Length; i++)
{
var classNum = _partitionClass[i];
for (int j = 0; j < _classDimensions[classNum]; j++)
{
xList.Add((int)packet.ReadBits(rangeBits));
}
}
_xList = xList.ToArray();
// precalc the low and high neighbors (and init the sort table)
_lNeigh = new int[xList.Count];
_hNeigh = new int[xList.Count];
_sortIdx = new int[xList.Count];
_sortIdx[0] = 0;
_sortIdx[1] = 1;
for (int i = 2; i < _lNeigh.Length; i++)
{
_lNeigh[i] = 0;
_hNeigh[i] = 1;
_sortIdx[i] = i;
for (int j = 2; j < i; j++)
{
var temp = _xList[j];
if (temp < _xList[i])
{
if (temp > _xList[_lNeigh[i]]) _lNeigh[i] = j;
}
else
{
if (temp < _xList[_hNeigh[i]]) _hNeigh[i] = j;
}
}
}
// precalc the sort table
for (int i = 0; i < _sortIdx.Length - 1; i++)
{
for (int j = i + 1; j < _sortIdx.Length; j++)
{
if (_xList[i] == _xList[j]) throw new InvalidDataException();
if (_xList[_sortIdx[i]] > _xList[_sortIdx[j]])
{
// swap the sort indexes
var temp = _sortIdx[i];
_sortIdx[i] = _sortIdx[j];
_sortIdx[j] = temp;
}
}
}
// pre-create our packet data instances
_reusablePacketData = new PacketData1[_vorbis._channels];
for (int i = 0; i < _reusablePacketData.Length; i++)
{
_reusablePacketData[i] = new PacketData1();
}
}
protected override void Init(DataPacket packet)
{
// this is pretty well stolen directly from libvorbis... BSD license
_begin = (int)packet.ReadBits(24);
_end = (int)packet.ReadBits(24);
_partitionSize = (int)packet.ReadBits(24) + 1;
_classifications = (int)packet.ReadBits(6) + 1;
_classBook = _vorbis.Books[(int)packet.ReadBits(8)];
_cascade = new int[_classifications];
var acc = 0;
for (int i = 0; i < _classifications; i++)
{
var low_bits = (int)packet.ReadBits(3);
if (packet.ReadBit())
{
_cascade[i] = (int)packet.ReadBits(5) << 3 | low_bits;
}
else
{
_cascade[i] = low_bits;
}
acc += icount(_cascade[i]);
}
var bookNums = new int[acc];
for (var i = 0; i < acc; i++)
{
bookNums[i] = (int)packet.ReadBits(8);
if (_vorbis.Books[bookNums[i]].MapType == 0) throw new InvalidDataException();
}
var entries = _classBook.Entries;
var dim = _classBook.Dimensions;
var partvals = 1;
while (dim > 0)
{
partvals *= _classifications;
if (partvals > entries) throw new InvalidDataException();
--dim;
}
// now the lookups
dim = _classBook.Dimensions;
_books = new VorbisCodebook[_classifications][];
acc = 0;
var maxstage = 0;
int stages;
for (int j = 0; j < _classifications; j++)
{
stages = Utils.ilog(_cascade[j]);
_books[j] = new VorbisCodebook[stages];
if (stages > 0)
{
maxstage = Math.Max(maxstage, stages);
for (int k = 0; k < stages; k++)
{
if ((_cascade[j] & (1 << k)) > 0)
{
_books[j][k] = _vorbis.Books[bookNums[acc++]];
}
}
}
}
_maxStages = maxstage;
_decodeMap = new int[partvals][];
for (int j = 0; j < partvals; j++)
{
var val = j;
var mult = partvals / _classifications;
_decodeMap[j] = new int[_classBook.Dimensions];
for (int k = 0; k < _classBook.Dimensions; k++)
{
var deco = val / mult;
val -= deco * mult;
mult /= _classifications;
_decodeMap[j][k] = deco;
}
}
_entryCache = new int[_partitionSize];
_partWordCache = new int[_vorbis._channels][][];
var maxPartWords = ((_end - _begin) / _partitionSize + _classBook.Dimensions - 1) / _classBook.Dimensions;
for (int ch = 0; ch < _vorbis._channels; ch++)
{
_partWordCache[ch] = new int[maxPartWords][];
}
}
void UpdatePosition(int samplesDecoded, DataPacket packet)
{
_samples += samplesDecoded;
if (packet.IsResync)
{
// during a resync, we have to go through and watch for the next "marker"
_currentPosition = -packet.PageGranulePosition;
// _currentPosition will now be end of the page... wait for the value to change, then go back and repopulate the granule positions accordingly...
_resyncQueue.Push(packet);
}
else
{
if (samplesDecoded > 0)
{
_currentPosition += samplesDecoded;
packet.GranulePosition = _currentPosition;
if (_currentPosition < 0)
{
if (packet.PageGranulePosition > -_currentPosition)
{
// we now have a valid granuleposition... populate the queued packets' GranulePositions
var gp = _currentPosition - samplesDecoded;
while (_resyncQueue.Count > 0)
{
var pkt = _resyncQueue.Pop();
var temp = pkt.GranulePosition + gp;
pkt.GranulePosition = gp;
gp = temp;
}
}
else
{
packet.GranulePosition = -samplesDecoded;
_resyncQueue.Push(packet);
}
}
else if (packet.IsEndOfStream && _currentPosition > packet.PageGranulePosition)
{
var diff = (int)(_currentPosition - packet.PageGranulePosition);
if (diff >= 0)
{
_preparedLength -= diff;
_currentPosition -= diff;
}
else
{
// uh-oh. We're supposed to have more samples to this point...
_preparedLength = 0;
}
packet.GranulePosition = packet.PageGranulePosition;
_eosFound = true;
}
}
}
}
protected override void Init(DataPacket packet)
{
}
void SetParametersChanging(object sender, ParameterChangeEventArgs e)
{
_parameterChangePacket = e.FirstPacket;
}
protected override bool WriteVectors(VorbisCodebook codebook, DataPacket packet, float[][] residue, int channel, int offset, int partitionSize)
{
var chPtr = 0;
offset /= _channels;
for (int c = 0; c < partitionSize; )
{
var entry = codebook.DecodeScalar(packet);
if (entry == -1)
{
return true;
}
for (var d = 0; d < codebook.Dimensions; d++, c++)
{
residue[chPtr][offset] += codebook[entry, d];
if (++chPtr == _channels)
{
chPtr = 0;
offset++;
}
}
}
return false;
}
protected override void Init(DataPacket packet)
{
var submapCount = 1;
if (packet.ReadBit()) submapCount += (int)packet.ReadBits(4);
// square polar mapping
var couplingSteps = 0;
if (packet.ReadBit())
{
couplingSteps = (int)packet.ReadBits(8) + 1;
}
var couplingBits = Utils.ilog(_vorbis._channels - 1);
CouplingSteps = new CouplingStep[couplingSteps];
for (int j = 0; j < couplingSteps; j++)
{
var magnitude = (int)packet.ReadBits(couplingBits);
var angle = (int)packet.ReadBits(couplingBits);
if (magnitude == angle || magnitude > _vorbis._channels - 1 || angle > _vorbis._channels - 1)
throw new InvalidDataException();
CouplingSteps[j] = new CouplingStep { Angle = angle, Magnitude = magnitude };
}
// reserved bits
if (packet.ReadBits(2) != 0UL) throw new InvalidDataException();
// channel multiplex
var mux = new int[_vorbis._channels];
if (submapCount > 1)
{
for (int c = 0; c < ChannelSubmap.Length; c++)
{
mux[c] = (int)packet.ReadBits(4);
if (mux[c] >= submapCount) throw new InvalidDataException();
}
}
// submaps
Submaps = new Submap[submapCount];
for (int j = 0; j < submapCount; j++)
{
packet.ReadBits(8); // unused placeholder
var floorNum = (int)packet.ReadBits(8);
if (floorNum >= _vorbis.Floors.Length) throw new InvalidDataException();
var residueNum = (int)packet.ReadBits(8);
if (residueNum >= _vorbis.Residues.Length) throw new InvalidDataException();
Submaps[j] = new Submap
{
Floor = _vorbis.Floors[floorNum],
Residue = _vorbis.Residues[floorNum]
};
}
ChannelSubmap = new Submap[_vorbis._channels];
for (int c = 0; c < ChannelSubmap.Length; c++)
{
ChannelSubmap[c] = Submaps[mux[c]];
}
}
// We can use the type 0 logic by saying we're doing a single channel buffer big enough to hold the samples for all channels
// This works because WriteVectors(...) "knows" the correct channel count and processes the data accordingly.
internal override float[][] Decode(DataPacket packet, bool[] doNotDecode, int channels, int blockSize)
{
_channels = channels;
return base.Decode(packet, doNotDecode, 1, blockSize * channels);
}
protected override bool WriteVectors(VorbisCodebook codebook, DataPacket packet, float[][] residue, int channel, int offset, int partitionSize)
{
var res = residue[channel];
for (int i = 0; i < partitionSize; )
{
var entry = codebook.DecodeScalar(packet);
if (entry == -1)
{
return true;
}
for (int j = 0; j < codebook.Dimensions; i++, j++)
{
res[offset + i] += codebook[entry, j];
}
}
return false;
}
protected virtual bool WriteVectors(VorbisCodebook codebook, DataPacket packet, float[][] residue, int channel, int offset, int partitionSize)
{
var res = residue[channel];
var step = partitionSize / codebook.Dimensions;
for (int i = 0; i < step; i++)
{
if ((_entryCache[i] = codebook.DecodeScalar(packet)) == -1)
{
return true;
}
}
for (int i = 0; i < codebook.Dimensions; i++)
{
for (int j = 0; j < step; j++, offset++)
{
res[offset] += codebook[_entryCache[j], i];
}
}
return false;
}
void InitTree(DataPacket packet)
{
bool sparse;
int total = 0;
if (packet.ReadBit())
{
// ordered
var len = (int)packet.ReadBits(5) + 1;
for (var i = 0; i < Entries; )
{
var cnt = (int)packet.ReadBits(Utils.ilog(Entries - i));
while (--cnt >= 0)
{
Lengths[i++] = len;
}
++len;
}
total = 0;
sparse = false;
}
else
{
// unordered
sparse = packet.ReadBit();
for (var i = 0; i < Entries; i++)
{
if (!sparse || packet.ReadBit())
{
Lengths[i] = (int)packet.ReadBits(5) + 1;
++total;
}
else
{
Lengths[i] = -1;
}
}
}
MaxBits = Lengths.Max();
int sortedCount = 0;
int[] codewordLengths = null;
if (sparse && total >= Entries >> 2)
{
codewordLengths = new int[Entries];
Array.Copy(Lengths, codewordLengths, Entries);
sparse = false;
}
// compute size of sorted tables
if (sparse)
{
sortedCount = total;
}
else
{
sortedCount = 0;
}
int sortedEntries = sortedCount;
int[] values = null;
int[] codewords = null;
if (!sparse)
{
codewords = new int[Entries];
}
else if (sortedEntries != 0)
{
codewordLengths = new int[sortedEntries];
codewords = new int[sortedEntries];
values = new int[sortedEntries];
}
if (!ComputeCodewords(sparse, sortedEntries, codewords, codewordLengths, len: Lengths, n: Entries, values: values)) throw new InvalidDataException();
PrefixList = Huffman.BuildPrefixedLinkedList(values ?? Enumerable.Range(0, codewords.Length).ToArray(), codewordLengths ?? Lengths, codewords, out PrefixBitLength, out PrefixOverflowTree);
}
bool ProcessStreamHeader(DataPacket packet)
{
if (!packet.ReadBytes(7).SequenceEqual(new byte[] { 0x01, 0x76, 0x6f, 0x72, 0x62, 0x69, 0x73 }))
{
// don't mark the packet as done... it might be used elsewhere
_glueBits += packet.Length * 8;
return false;
}
if (!_pagesSeen.Contains((_lastPageSeen = packet.PageSequenceNumber))) _pagesSeen.Add(_lastPageSeen);
_glueBits += 56;
var startPos = packet.BitsRead;
if (packet.ReadInt32() != 0) throw new InvalidDataException("Only Vorbis stream version 0 is supported.");
_channels = packet.ReadByte();
_sampleRate = packet.ReadInt32();
_upperBitrate = packet.ReadInt32();
_nominalBitrate = packet.ReadInt32();
_lowerBitrate = packet.ReadInt32();
Block0Size = 1 << (int)packet.ReadBits(4);
Block1Size = 1 << (int)packet.ReadBits(4);
if (_nominalBitrate == 0)
{
if (_upperBitrate > 0 && _lowerBitrate > 0)
{
_nominalBitrate = (_upperBitrate + _lowerBitrate) / 2;
}
}
_metaBits += packet.BitsRead - startPos + 8;
_wasteHdrBits += 8 * packet.Length - packet.BitsRead;
return true;
}
bool UnpackPacket(DataPacket packet)
{
// make sure we're on an audio packet
if (packet.ReadBit())
{
// we really can't do anything... count the bits as waste
return false;
}
// get mode and prev/next flags
var modeBits = _modeFieldBits;
_mode = Modes[(int)packet.ReadBits(_modeFieldBits)];
if (_mode.BlockFlag)
{
_prevFlag = packet.ReadBit();
_nextFlag = packet.ReadBit();
modeBits += 2;
}
else
{
_prevFlag = _nextFlag = false;
}
if (packet.IsShort) return false;
var startBits = packet.BitsRead;
var halfBlockSize = _mode.BlockSize / 2;
// read the noise floor data (but don't decode yet)
for (int i = 0; i < _channels; i++)
{
_floorData[i] = _mode.Mapping.ChannelSubmap[i].Floor.UnpackPacket(packet, _mode.BlockSize, i);
_noExecuteChannel[i] = !_floorData[i].ExecuteChannel;
// go ahead and clear the residue buffers
Array.Clear(_residue[i], 0, halfBlockSize);
}
// make sure we handle no-energy channels correctly given the couplings...
foreach (var step in _mode.Mapping.CouplingSteps)
{
if (_floorData[step.Angle].ExecuteChannel || _floorData[step.Magnitude].ExecuteChannel)
{
_floorData[step.Angle].ForceEnergy = true;
_floorData[step.Magnitude].ForceEnergy = true;
}
}
var floorBits = packet.BitsRead - startBits;
startBits = packet.BitsRead;
foreach (var subMap in _mode.Mapping.Submaps)
{
for (int j = 0; j < _channels; j++)
{
if (_mode.Mapping.ChannelSubmap[j] != subMap)
{
_floorData[j].ForceNoEnergy = true;
}
}
var rTemp = subMap.Residue.Decode(packet, _noExecuteChannel, _channels, _mode.BlockSize);
for (int c = 0; c < _channels; c++)
{
var r = _residue[c];
var rt = rTemp[c];
for (int i = 0; i < halfBlockSize; i++)
{
r[i] += rt[i];
}
}
}
_glueBits += 1;
_modeBits += modeBits;
_floorBits += floorBits;
_resBits += packet.BitsRead - startBits;
_wasteBits += 8 * packet.Length - packet.BitsRead;
_packetCount += 1;
return true;
}
protected override void Init(DataPacket packet)
{
// this is pretty well stolen directly from libvorbis... BSD license
_order = (int)packet.ReadBits(8);
_rate = (int)packet.ReadBits(16);
_bark_map_size = (int)packet.ReadBits(16);
_ampBits = (int)packet.ReadBits(6);
_ampOfs = (int)packet.ReadBits(8);
_books = new VorbisCodebook[(int)packet.ReadBits(4) + 1];
if (_order < 1 || _rate < 1 || _bark_map_size < 1 || _books.Length == 0) throw new InvalidDataException();
_ampDiv = (1 << _ampBits) - 1;
for (int i = 0; i < _books.Length; i++)
{
var num = (int)packet.ReadBits(8);
if (num < 0 || num >= _vorbis.Books.Length) throw new InvalidDataException();
var book = _vorbis.Books[num];
if (book.MapType == 0 || book.Dimensions < 1) throw new InvalidDataException();
_books[i] = book;
}
_bookBits = Utils.ilog(_books.Length);
_barkMaps = new Dictionary<int, int[]>();
_barkMaps[_vorbis.Block0Size] = SynthesizeBarkCurve(_vorbis.Block0Size / 2);
_barkMaps[_vorbis.Block1Size] = SynthesizeBarkCurve(_vorbis.Block1Size / 2);
_wMap = new Dictionary<int, float[]>();
_wMap[_vorbis.Block0Size] = SynthesizeWDelMap(_vorbis.Block0Size / 2);
_wMap[_vorbis.Block1Size] = SynthesizeWDelMap(_vorbis.Block1Size / 2);
_reusablePacketData = new PacketData0[_vorbis._channels];
for (int i = 0; i < _reusablePacketData.Length; i++)
{
_reusablePacketData[i] = new PacketData0() { Coeff = new float[_order + 1] };
}
}
internal void Init(DataPacket packet)
{
// first, check the sync pattern
var chkVal = packet.ReadBits(24);
if (chkVal != 0x564342UL) throw new InvalidDataException();
// get the counts
Dimensions = (int)packet.ReadBits(16);
Entries = (int)packet.ReadBits(24);
// init the storage
Lengths = new int[Entries];
InitTree(packet);
InitLookupTable(packet);
}
internal override float[][] Decode(DataPacket packet, bool[] doNotDecode, int channels, int blockSize)
{
var residue = GetResidueBuffer(doNotDecode.Length);
// this is pretty well stolen directly from libvorbis... BSD license
var end = _end < blockSize / 2 ? _end : blockSize / 2;
var n = end - _begin;
if (n > 0 && doNotDecode.Contains(false))
{
var partVals = n / _partitionSize;
var partWords = (partVals + _classBook.Dimensions - 1) / _classBook.Dimensions;
for (int j = 0; j < channels; j++)
{
Array.Clear(_partWordCache[j], 0, partWords);
}
for (int s = 0; s < _maxStages; s++)
{
for (int i = 0, l = 0; i < partVals; l++)
{
if (s == 0)
{
for (int j = 0; j < channels; j++)
{
var idx = _classBook.DecodeScalar(packet);
if (idx >= 0 && idx < _decodeMap.Length)
{
_partWordCache[j][l] = _decodeMap[idx];
}
else
{
i = partVals;
s = _maxStages;
break;
}
}
}
for (int k = 0; i < partVals && k < _classBook.Dimensions; k++, i++)
{
var offset = _begin + i * _partitionSize;
for (int j = 0; j < channels; j++)
{
var idx = _partWordCache[j][l][k];
if ((_cascade[idx] & (1 << s)) != 0)
{
var book = _books[idx][s];
if (book != null)
{
if (WriteVectors(book, packet, residue, j, offset, _partitionSize))
{
// bad packet... exit now and try to use what we already have
i = partVals;
s = _maxStages;
break;
}
}
}
}
}
}
}
}
return residue;
}
protected abstract void Init(DataPacket packet);
internal abstract float[][] Decode(DataPacket packet, bool[] doNotDecode, int channels, int blockSize);
internal override PacketData UnpackPacket(DataPacket packet, int blockSize, int channel)
{
var data = _reusablePacketData[channel];
data.BlockSize = blockSize;
data.ForceEnergy = false;
data.ForceNoEnergy = false;
data.Amp = packet.ReadBits(_ampBits);
if (data.Amp > 0f)
{
// this is pretty well stolen directly from libvorbis... BSD license
Array.Clear(data.Coeff, 0, data.Coeff.Length);
data.Amp = (float)(data.Amp / _ampDiv * _ampOfs);
var bookNum = (uint)packet.ReadBits(_bookBits);
if (bookNum >= _books.Length)
{
// we ran out of data or the packet is corrupt... 0 the floor and return
data.Amp = 0;
return data;
}
var book = _books[bookNum];
// first, the book decode...
for (int i = 0; i < _order; )
{
var entry = book.DecodeScalar(packet);
if (entry == -1)
{
// we ran out of data or the packet is corrupt... 0 the floor and return
data.Amp = 0;
return data;
}
for (int j = 0; i < _order && j < book.Dimensions; j++, i++)
{
data.Coeff[i] = book[entry, j];
}
}
// then, the "averaging"
var last = 0f;
for (int j = 0; j < _order; )
{
for (int k = 0; j < _order && k < book.Dimensions; j++, k++)
{
data.Coeff[j] += last;
}
last = data.Coeff[j - 1];
}
}
return data;
}
void ProcessParameterChange(DataPacket packet)
{
_parameterChangePacket = null;
// try to do a stream header...
var wasPeek = false;
var doFullReset = false;
if (ProcessStreamHeader(packet))
{
packet.Done();
wasPeek = true;
doFullReset = true;
packet = _packetProvider.PeekNextPacket();
if (packet == null) throw new InvalidDataException("Couldn't get next packet!");
}
// try to do a comment header...
if (LoadComments(packet))
{
if (wasPeek)
{
_packetProvider.GetNextPacket().Done();
}
else
{
packet.Done();
}
wasPeek = true;
packet = _packetProvider.PeekNextPacket();
if (packet == null) throw new InvalidDataException("Couldn't get next packet!");
}
// try to do a book header...
if (LoadBooks(packet))
{
if (wasPeek)
{
_packetProvider.GetNextPacket().Done();
}
else
{
packet.Done();
}
}
ResetDecoder(doFullReset);
}