public FlakeReader(string path, Stream IO)
{
_path = path;
_IO = IO != null ? IO : new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read, 0x10000);
crc8 = new Crc8();
crc16 = new Crc16();
_framesBuffer = new byte[0x20000];
decode_metadata();
frame = new FlacFrame(PCM.ChannelCount);
framereader = new BitReader();
//max_frame_size = 16 + ((Flake.MAX_BLOCKSIZE * PCM.BitsPerSample * PCM.ChannelCount + 1) + 7) >> 3);
if (((int)max_frame_size * PCM.BitsPerSample * PCM.ChannelCount * 2 >> 3) > _framesBuffer.Length)
{
byte[] temp = _framesBuffer;
_framesBuffer = new byte[((int)max_frame_size * PCM.BitsPerSample * PCM.ChannelCount * 2 >> 3)];
if (_framesBufferLength > 0)
Array.Copy(temp, _framesBufferOffset, _framesBuffer, 0, _framesBufferLength);
_framesBufferOffset = 0;
}
_samplesInBuffer = 0;
if ((PCM.BitsPerSample != 16 && PCM.BitsPerSample != 24) || PCM.ChannelCount != 2 || (PCM.SampleRate != 44100 && PCM.SampleRate != 48000))
throw new Exception("invalid flac file");
samplesBuffer = new int[Flake.MAX_BLOCKSIZE * PCM.ChannelCount];
residualBuffer = new int[Flake.MAX_BLOCKSIZE * PCM.ChannelCount];
}
public FlakeReader(Stream IO)
{
if (IO == null)
{
throw new ArgumentNullException("IO");
}
_IO = IO;
crc8 = new Crc8();
_framesBuffer = new byte[0x20000];
decode_metadata();
frame = new FlacFrame(PCM.ChannelCount);
framereader = new BitReader();
//max_frame_size = 16 + ((Flake.MAX_BLOCKSIZE * PCM.BitsPerSample * PCM.ChannelCount + 1) + 7) >> 3);
if (((int)max_frame_size * PCM.BitsPerSample * PCM.ChannelCount * 2 >> 3) > _framesBuffer.Length)
{
byte[] temp = _framesBuffer;
_framesBuffer = new byte[((int)max_frame_size * PCM.BitsPerSample * PCM.ChannelCount * 2 >> 3)];
if (_framesBufferLength > 0)
Array.Copy(temp, _framesBufferOffset, _framesBuffer, 0, _framesBufferLength);
_framesBufferOffset = 0;
}
_samplesInBuffer = 0;
if (PCM.BitsPerSample != 16 && PCM.BitsPerSample != 24)
throw new Exception("invalid flac file");
samplesBuffer = new int[Flake.MAX_BLOCKSIZE * PCM.ChannelCount];
residualBuffer = new int[Flake.MAX_BLOCKSIZE * PCM.ChannelCount];
}
unsafe void restore_samples_fixed(FlacFrame frame, int ch)
{
FlacSubframeInfo sub = frame.subframes[ch];
AudioSamples.MemCpy(sub.samples, sub.best.residual, sub.best.order);
int *data = sub.samples + sub.best.order;
int *residual = sub.best.residual + sub.best.order;
int data_len = frame.blocksize - sub.best.order;
int s0, s1, s2;
switch (sub.best.order)
{
case 0:
AudioSamples.MemCpy(data, residual, data_len);
break;
case 1:
s1 = data[-1];
for (int i = data_len; i > 0; i--)
{
s1 += *(residual++);
*(data++) = s1;
}
//data[i] = residual[i] + data[i - 1];
break;
case 2:
s2 = data[-2];
s1 = data[-1];
for (int i = data_len; i > 0; i--)
{
s0 = *(residual++) + (s1 << 1) - s2;
*(data++) = s0;
s2 = s1;
s1 = s0;
}
//data[i] = residual[i] + data[i - 1] * 2 - 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;
}
}
public FlakeReader(AudioPCMConfig _pcm)
{
pcm = _pcm;
crc8 = new Crc8();
crc16 = new Crc16();
samplesBuffer = new int[Flake.MAX_BLOCKSIZE * PCM.ChannelCount];
residualBuffer = new int[Flake.MAX_BLOCKSIZE * PCM.ChannelCount];
frame = new FlacFrame(PCM.ChannelCount);
framereader = new BitReader();
}
unsafe void Decode_subframe_fixed(BitReader bitreader, FlacFrame frame, int ch)
{
// warm-up samples
int obits = frame.subframes[ch].obits;
for (int i = 0; i < frame.subframes[ch].best.order; i++)
{
frame.subframes[ch].best.residual[i] = bitreader.Readbits_signed(obits);
}
// residual
Decode_residual(bitreader, frame, ch);
}
unsafe void Decode_residual(BitReader bitreader, FlacFrame frame, int ch)
{
// rice-encoded block
// coding method
frame.subframes[ch].best.rc.coding_method = (int)bitreader.Readbits(2); // ????? == 0
if (frame.subframes[ch].best.rc.coding_method != 0 && frame.subframes[ch].best.rc.coding_method != 1)
{
throw new Exception("unsupported residual coding");
}
// partition order
frame.subframes[ch].best.rc.porder = (int)bitreader.Readbits(4);
if (frame.subframes[ch].best.rc.porder > 8)
{
throw new Exception("invalid partition order");
}
int psize = frame.blocksize >> frame.subframes[ch].best.rc.porder;
int res_cnt = psize - frame.subframes[ch].best.order;
int rice_len = 4 + frame.subframes[ch].best.rc.coding_method;
// residual
int j = frame.subframes[ch].best.order;
int *r = frame.subframes[ch].best.residual + j;
for (int p = 0; p < (1 << frame.subframes[ch].best.rc.porder); p++)
{
if (p == 1)
{
res_cnt = psize;
}
int n = Math.Min(res_cnt, frame.blocksize - j);
int k = frame.subframes[ch].best.rc.rparams[p] = (int)bitreader.Readbits(rice_len);
if (k == (1 << rice_len) - 1)
{
k = frame.subframes[ch].best.rc.esc_bps[p] = (int)bitreader.Readbits(5);
for (int i = n; i > 0; i--)
{
*(r++) = bitreader.Readbits_signed((int)k);
}
}
else
{
bitreader.Read_rice_block(n, (int)k, r);
r += n;
}
j += n;
}
}
unsafe void Restore_samples_lpc(FlacFrame frame, int ch)
{
FlacSubframeInfo sub = frame.subframes[ch];
ulong csum = 0;
fixed(int *coefs = sub.best.coefs)
{
for (int i = sub.best.order; i > 0; i--)
{
csum += (ulong)Math.Abs(coefs[i - 1]);
}
if ((csum << sub.obits) >= 1UL << 32)
{
Lpc.Decode_residual_long(sub.best.residual, sub.samples, frame.blocksize, sub.best.order, coefs, sub.best.shift);
}
else
{
Lpc.Decode_residual(sub.best.residual, sub.samples, frame.blocksize, sub.best.order, coefs, sub.best.shift);
}
}
}
public FlakeReader(Stream IO)
{
if (IO == null)
{
throw new ArgumentNullException("IO");
}
_IO = IO;
crc8 = new Crc8();
_framesBuffer = new byte[0x20000];
decode_metadata();
frame = new FlacFrame(PCM.ChannelCount);
framereader = new BitReader();
//max_frame_size = 16 + ((Flake.MAX_BLOCKSIZE * PCM.BitsPerSample * PCM.ChannelCount + 1) + 7) >> 3);
if (((int)max_frame_size * PCM.BitsPerSample * PCM.ChannelCount * 2 >> 3) > _framesBuffer.Length)
{
byte[] temp = _framesBuffer;
_framesBuffer = new byte[((int)max_frame_size * PCM.BitsPerSample * PCM.ChannelCount * 2 >> 3)];
if (_framesBufferLength > 0)
{
Array.Copy(temp, _framesBufferOffset, _framesBuffer, 0, _framesBufferLength);
}
_framesBufferOffset = 0;
}
_samplesInBuffer = 0;
if (PCM.BitsPerSample != 16 && PCM.BitsPerSample != 24)
{
throw new Exception("invalid flac file");
}
samplesBuffer = new int[Flake.MAX_BLOCKSIZE * PCM.ChannelCount];
residualBuffer = new int[Flake.MAX_BLOCKSIZE * PCM.ChannelCount];
}
unsafe void postprocess_coefs(FlacFrame frame, FlacSubframe sf, int ch)
{
if (eparams.development_mode < 0)
return;
if (sf.type != SubframeType.LPC || sf.order > 30)
return;
int orig_window = sf.window;
int orig_order = sf.order;
int orig_shift = sf.shift;
int orig_cbits = sf.cbits;
uint orig_size = sf.size;
var orig_coefs = stackalloc int[orig_order];
for (int i = 0; i < orig_order; i++) orig_coefs[i] = sf.coefs[i];
int orig_xx = -1;
int orig_seq = 0;
int maxxx = Math.Min(good_x[orig_order].Length, eparams.development_mode);
var pmax = get_max_p_order(eparams.max_partition_order, frame.blocksize, orig_order);
var pmin = Math.Min(eparams.min_partition_order, pmax);
ulong* sums = stackalloc ulong[(pmax + 1) * Flake.MAX_PARTITIONS];
while (true)
{
var best_coefs = stackalloc int[orig_order];
int best_shift = orig_shift;
int best_cbits = orig_cbits;
uint best_size = orig_size;
int best_xx = -1;
for (int xx = -1; xx < maxxx; xx++)
{
int x = xx;
if (xx < 0)
{
if (orig_xx < 0 || maxxx < 1/*3*/)// || (orig_xx >> orig_order) != 0)
continue;
x = orig_xx;
orig_seq++;
}
else
{
orig_seq = 0;
if (orig_order < good_x.Length && good_x[orig_order] != null)
x = good_x[orig_order][xx];
}
frame.current.type = SubframeType.LPC;
frame.current.order = orig_order;
frame.current.window = orig_window;
frame.current.shift = orig_shift;
frame.current.cbits = orig_cbits;
if (((x >> orig_order) & 1) != 0)
{
frame.current.shift--;
frame.current.cbits--;
if (frame.current.shift < 0 || frame.current.cbits < 2)
continue;
}
ulong csum = 0;
int qmax = (1 << (frame.current.cbits - 1)) - 1;
for (int i = 0; i < frame.current.order; i++)
{
int shift = (x >> orig_order) & 1;
int increment = (x == 1 << orig_order) ? 0 : (((x >> i) & 1) << 1) - 1;
frame.current.coefs[i] = (orig_coefs[i] + (increment << orig_seq)) >> shift;
if (frame.current.coefs[i] < -(qmax + 1)) frame.current.coefs[i] = -(qmax + 1);
if (frame.current.coefs[i] > qmax) frame.current.coefs[i] = qmax;
csum += (ulong)Math.Abs(frame.current.coefs[i]);
}
fixed (int* coefs = frame.current.coefs)
{
if ((csum << frame.subframes[ch].obits) >= 1UL << 32)
lpc.encode_residual_long(frame.current.residual, frame.subframes[ch].samples, frame.blocksize, frame.current.order, coefs, frame.current.shift);
else
lpc.encode_residual(frame.current.residual, frame.subframes[ch].samples, frame.blocksize, frame.current.order, coefs, frame.current.shift);
}
var cur_size = calc_rice_params(frame.current.rc, pmin, pmax, frame.current.residual, (uint)frame.blocksize, (uint)frame.current.order, Settings.PCM.BitsPerSample);
frame.current.size = (uint)(frame.current.order * frame.subframes[ch].obits + 4 + 5 + frame.current.order * frame.current.cbits + 6 + (int)cur_size);
if (frame.current.size < best_size)
{
//var dif = best_size - frame.current.size;
for (int i = 0; i < frame.current.order; i++) best_coefs[i] = frame.current.coefs[i];
best_shift = frame.current.shift;
best_cbits = frame.current.cbits;
best_size = frame.current.size;
best_xx = x;
frame.ChooseBestSubframe(ch);
//if (dif > orig_order * 5)
// break;
}
if (xx < 0 && best_size < orig_size)
break;
}
if (best_size < orig_size)
{
//if (best_xx >= 0) best_x[order, best_xx]++;
//if (orig_size != 0x7FFFFFFF)
// System.Console.Write(string.Format(" {0}[{1:x}]", orig_size - best_size, best_xx));
for (int i = 0; i < orig_order; i++) orig_coefs[i] = best_coefs[i];
orig_shift = best_shift;
orig_cbits = best_cbits;
orig_size = best_size;
orig_xx = best_xx;
}
else
{
break;
}
}
//if (orig_size != 0x7FFFFFFF)
// System.Console.WriteLine();
//if (frame_count % 0x400 == 0)
//{
// for (int o = 0; o < best_x.GetLength(0); o++)
// {
// //for (int x = 0; x <= (1 << o); x++)
// // if (best_x[o, x] != 0)
// // System.Console.WriteLine(string.Format("{0:x2}\t{1:x4}\t{2}", o, x, best_x[o, x]));
// var s = new List<KeyValuePair<int, int>>();
// for (int x = 0; x < (1 << o); x++)
// if (best_x[o, x] != 0)
// s.Add(new KeyValuePair<int, int>(x, best_x[o, x]));
// s.Sort((x, y) => y.Value.CompareTo(x.Value));
// foreach (var x in s)
// System.Console.WriteLine(string.Format("{0:x2}\t{1:x4}\t{2}", o, x.Key, x.Value));
// int i = 0;
// foreach (var x in s)
// {
// System.Console.Write(string.Format(o <= 8 ? "0x{0:x2}," : "0x{0:x3},", x.Key));
// if ((++i) % 16 == 0)
// System.Console.WriteLine();
// }
// System.Console.WriteLine();
// }
//}
}
unsafe void restore_samples(FlacFrame frame)
{
for (int ch = 0; ch < PCM.ChannelCount; ch++)
{
switch (frame.subframes[ch].best.type)
{
case SubframeType.Constant:
AudioSamples.MemSet(frame.subframes[ch].samples, frame.subframes[ch].best.residual[0], frame.blocksize);
break;
case SubframeType.Verbatim:
AudioSamples.MemCpy(frame.subframes[ch].samples, frame.subframes[ch].best.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* s = frame.subframes[ch].samples;
int x = (int) frame.subframes[ch].wbits;
for (int i = frame.blocksize; i > 0; i--)
*(s++) <<= x;
}
}
if (frame.ch_mode != ChannelMode.NotStereo)
{
int* l = frame.subframes[0].samples;
int* r = frame.subframes[1].samples;
switch (frame.ch_mode)
{
case ChannelMode.LeftRight:
break;
case ChannelMode.MidSide:
for (int i = frame.blocksize; i > 0; i--)
{
int mid = *l;
int side = *r;
mid <<= 1;
mid |= (side & 1); /* i.e. if 'side' is odd... */
*(l++) = (mid + side) >> 1;
*(r++) = (mid - side) >> 1;
}
break;
case ChannelMode.LeftSide:
for (int i = frame.blocksize; i > 0; i--)
{
int _l = *(l++), _r = *r;
*(r++) = _l - _r;
}
break;
case ChannelMode.RightSide:
for (int i = frame.blocksize; i > 0; i--)
*(l++) += *(r++);
break;
}
}
}
public FlakeWriter(string path, Stream IO, AudioPCMConfig pcm)
{
_pcm = pcm;
//if (_pcm.BitsPerSample != 16)
// throw new Exception("Bits per sample must be 16.");
if (_pcm.ChannelCount != 2)
throw new Exception("ChannelCount must be 2.");
channels = pcm.ChannelCount;
// flake_validate_params
_path = path;
_IO = IO;
samplesBuffer = new int[Flake.MAX_BLOCKSIZE * (channels == 2 ? 4 : channels)];
residualBuffer = new int[Flake.MAX_BLOCKSIZE * (channels == 2 ? 10 : channels + 1)];
windowBuffer = new float[Flake.MAX_BLOCKSIZE * 2 * lpc.MAX_LPC_WINDOWS];
windowScale = new double[lpc.MAX_LPC_WINDOWS];
eparams.flake_set_defaults(_compressionLevel);
eparams.padding_size = 8192;
crc8 = new Crc8();
crc16 = new Crc16();
frame = new FlacFrame(channels * 2);
}
unsafe void encode_residual_pass2(FlacFrame frame, int ch)
{
encode_residual(frame, ch, eparams.prediction_type, eparams.order_method, 2, estimate_best_window(frame, ch));
}
unsafe void output_subframes(FlacFrame frame, BitWriter bitwriter)
{
for (int ch = 0; ch < channels; ch++)
{
FlacSubframeInfo sub = frame.subframes[ch];
// subframe header
int type_code = (int) sub.best.type;
if (sub.best.type == SubframeType.Fixed)
type_code |= sub.best.order;
if (sub.best.type == SubframeType.LPC)
type_code |= sub.best.order - 1;
bitwriter.writebits(1, 0);
bitwriter.writebits(6, type_code);
bitwriter.writebits(1, sub.wbits != 0 ? 1 : 0);
if (sub.wbits > 0)
bitwriter.writebits((int)sub.wbits, 1);
// subframe
switch (sub.best.type)
{
case SubframeType.Constant:
output_subframe_constant(frame, bitwriter, sub);
break;
case SubframeType.Verbatim:
output_subframe_verbatim(frame, bitwriter, sub);
break;
case SubframeType.Fixed:
output_subframe_fixed(frame, bitwriter, sub);
break;
case SubframeType.LPC:
output_subframe_lpc(frame, bitwriter, sub);
break;
}
}
}
output_subframe_fixed(FlacFrame frame, BitWriter bitwriter, FlacSubframeInfo sub)
{
// warm-up samples
for (int i = 0; i < sub.best.order; i++)
bitwriter.writebits_signed(sub.obits, sub.best.residual[i]);
// residual
output_residual(frame, bitwriter, sub);
}
output_subframe_constant(FlacFrame frame, BitWriter bitwriter, FlacSubframeInfo sub)
{
bitwriter.writebits_signed(sub.obits, sub.best.residual[0]);
}
unsafe void decode_subframe_lpc(BitReader bitreader, FlacFrame frame, int ch)
{
// warm-up samples
int obits = frame.subframes[ch].obits;
for (int i = 0; i < frame.subframes[ch].best.order; i++)
frame.subframes[ch].best.residual[i] = bitreader.readbits_signed(obits);
// LPC coefficients
frame.subframes[ch].best.cbits = (int)bitreader.readbits(4) + 1; // lpc_precision
frame.subframes[ch].best.shift = bitreader.readbits_signed(5);
if (frame.subframes[ch].best.shift < 0)
throw new Exception("negative shift");
for (int i = 0; i < frame.subframes[ch].best.order; i++)
frame.subframes[ch].best.coefs[i] = bitreader.readbits_signed(frame.subframes[ch].best.cbits);
// residual
decode_residual(bitreader, frame, ch);
}
unsafe void Decode_subframe_constant(BitReader bitreader, FlacFrame frame, int ch)
{
int obits = frame.subframes[ch].obits;
frame.subframes[ch].best.residual[0] = bitreader.Readbits_signed(obits);
}
unsafe void Decode_frame_header(BitReader bitreader, FlacFrame frame)
{
int header_start = bitreader.Position;
if (bitreader.Readbits(15) != 0x7FFC)
{
throw new Exception("invalid frame");
}
uint vbs = bitreader.Readbit();
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 (Flake.flac_bitdepths[bps_code] != PCM.BitsPerSample)
{
throw new Exception("unsupported bps coding");
}
uint t1 = bitreader.Readbit(); // == 0?????
if (t1 != 0)
{
throw new Exception("unsupported frame coding");
}
frame.frame_number = (int)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 = Flake.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 != PCM.ChannelCount)
{
throw new Exception("invalid channel mode");
}
// CRC-8 of frame header
byte crc = DoCRC ? crc8.ComputeChecksum(bitreader.Buffer, header_start, bitreader.Position - header_start) : (byte)0;
frame.crc8 = (byte)bitreader.Readbits(8);
if (DoCRC && frame.crc8 != crc)
{
throw new Exception("header crc mismatch");
}
}
public FlakeReader(AudioPCMConfig _pcm)
{
pcm = _pcm;
crc8 = new Crc8();
crc16 = new Crc16();
samplesBuffer = new int[Flake.MAX_BLOCKSIZE * PCM.ChannelCount];
residualBuffer = new int[Flake.MAX_BLOCKSIZE * PCM.ChannelCount];
frame = new FlacFrame(PCM.ChannelCount);
framereader = new BitReader();
}
unsafe void restore_samples_lpc(FlacFrame frame, int ch)
{
FlacSubframeInfo sub = frame.subframes[ch];
ulong csum = 0;
fixed (int* coefs = sub.best.coefs)
{
for (int i = sub.best.order; i > 0; i--)
csum += (ulong)Math.Abs(coefs[i - 1]);
if ((csum << sub.obits) >= 1UL << 32)
lpc.decode_residual_long(sub.best.residual, sub.samples, frame.blocksize, sub.best.order, coefs, sub.best.shift);
else
lpc.decode_residual(sub.best.residual, sub.samples, frame.blocksize, sub.best.order, coefs, sub.best.shift);
}
}
unsafe void restore_samples_fixed(FlacFrame frame, int ch)
{
FlacSubframeInfo sub = frame.subframes[ch];
AudioSamples.MemCpy(sub.samples, sub.best.residual, sub.best.order);
int* data = sub.samples + sub.best.order;
int* residual = sub.best.residual + sub.best.order;
int data_len = frame.blocksize - sub.best.order;
int s0, s1, s2;
switch (sub.best.order)
{
case 0:
AudioSamples.MemCpy(data, residual, data_len);
break;
case 1:
s1 = data[-1];
for (int i = data_len; i > 0; i--)
{
s1 += *(residual++);
*(data++) = s1;
}
//data[i] = residual[i] + data[i - 1];
break;
case 2:
s2 = data[-2];
s1 = data[-1];
for (int i = data_len; i > 0; i--)
{
s0 = *(residual++) + (s1 << 1) - s2;
*(data++) = s0;
s2 = s1;
s1 = s0;
}
//data[i] = residual[i] + data[i - 1] * 2 - 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 output_frame_header(FlacFrame frame, BitWriter bitwriter)
{
bitwriter.writebits(15, 0x7FFC);
bitwriter.writebits(1, eparams.variable_block_size > 0 ? 1 : 0);
bitwriter.writebits(4, frame.bs_code0);
bitwriter.writebits(4, sr_code0);
if (frame.ch_mode == ChannelMode.NotStereo)
bitwriter.writebits(4, ch_code);
else
bitwriter.writebits(4, (int) frame.ch_mode);
bitwriter.writebits(3, bps_code);
bitwriter.writebits(1, 0);
bitwriter.write_utf8(frame_count);
// custom block size
if (frame.bs_code1 >= 0)
{
if (frame.bs_code1 < 256)
bitwriter.writebits(8, frame.bs_code1);
else
bitwriter.writebits(16, frame.bs_code1);
}
// custom sample rate
if (sr_code1 > 0)
{
if (sr_code1 < 256)
bitwriter.writebits(8, sr_code1);
else
bitwriter.writebits(16, sr_code1);
}
// CRC-8 of frame header
bitwriter.flush();
byte crc = crc8.ComputeChecksum(frame_buffer, 0, bitwriter.Length);
bitwriter.writebits(8, crc);
}
unsafe void output_residual(FlacFrame frame, BitWriter bitwriter, FlacSubframeInfo sub)
{
// rice-encoded block
bitwriter.writebits(2, sub.best.rc.coding_method);
// partition order
int porder = sub.best.rc.porder;
int psize = frame.blocksize >> porder;
//assert(porder >= 0);
bitwriter.writebits(4, porder);
int res_cnt = psize - sub.best.order;
int rice_len = 4 + sub.best.rc.coding_method;
// residual
int j = sub.best.order;
fixed (byte* fixbuf = &frame_buffer[0])
for (int p = 0; p < (1 << porder); p++)
{
int k = sub.best.rc.rparams[p];
bitwriter.writebits(rice_len, k);
if (p == 1) res_cnt = psize;
int cnt = Math.Min(res_cnt, frame.blocksize - j);
bitwriter.write_rice_block_signed(fixbuf, k, sub.best.residual + j, cnt);
j += cnt;
}
}
unsafe void decode_subframe_fixed(BitReader bitreader, FlacFrame frame, int ch)
{
// warm-up samples
int obits = frame.subframes[ch].obits;
for (int i = 0; i < frame.subframes[ch].best.order; i++)
frame.subframes[ch].best.residual[i] = bitreader.readbits_signed(obits);
// residual
decode_residual(bitreader, frame, ch);
}
output_subframe_verbatim(FlacFrame frame, BitWriter bitwriter, FlacSubframeInfo sub)
{
int n = frame.blocksize;
for (int i = 0; i < n; i++)
bitwriter.writebits_signed(sub.obits, sub.samples[i]);
// Don't use residual here, because we don't copy samples to residual for verbatim frames.
}
unsafe void Decode_subframes(BitReader bitreader, FlacFrame frame)
{
fixed(int *r = residualBuffer, s = Samples)
for (int ch = 0; ch < PCM.ChannelCount; ch++)
{
// subframe header
uint t1 = bitreader.Readbit(); // ?????? == 0
if (t1 != 0)
{
throw new Exception("unsupported subframe coding (ch == " + ch.ToString() + ")");
}
int type_code = (int)bitreader.Readbits(6);
frame.subframes[ch].wbits = (int)bitreader.Readbit();
if (frame.subframes[ch].wbits != 0)
{
frame.subframes[ch].wbits += (int)bitreader.Read_unary();
}
frame.subframes[ch].obits = PCM.BitsPerSample - frame.subframes[ch].wbits;
switch (frame.ch_mode)
{
case ChannelMode.MidSide: frame.subframes[ch].obits += ch; break;
case ChannelMode.LeftSide: frame.subframes[ch].obits += ch; break;
case ChannelMode.RightSide: frame.subframes[ch].obits += 1 - ch; break;
}
frame.subframes[ch].best.type = (SubframeType)type_code;
frame.subframes[ch].best.order = 0;
if ((type_code & (uint)SubframeType.LPC) != 0)
{
frame.subframes[ch].best.order = (type_code - (int)SubframeType.LPC) + 1;
frame.subframes[ch].best.type = SubframeType.LPC;
}
else if ((type_code & (uint)SubframeType.Fixed) != 0)
{
frame.subframes[ch].best.order = (type_code - (int)SubframeType.Fixed);
frame.subframes[ch].best.type = SubframeType.Fixed;
}
frame.subframes[ch].best.residual = r + ch * Flake.MAX_BLOCKSIZE;
frame.subframes[ch].samples = s + ch * Flake.MAX_BLOCKSIZE;
// subframe
switch (frame.subframes[ch].best.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");
}
}
}
output_subframe_lpc(FlacFrame frame, BitWriter bitwriter, FlacSubframeInfo sub)
{
// warm-up samples
for (int i = 0; i < sub.best.order; i++)
bitwriter.writebits_signed(sub.obits, sub.best.residual[i]);
// LPC coefficients
int cbits = 1;
for (int i = 0; i < sub.best.order; i++)
while (cbits < 16 && sub.best.coefs[i] != (sub.best.coefs[i] << (32 - cbits)) >> (32 - cbits))
cbits++;
bitwriter.writebits(4, cbits - 1);
bitwriter.writebits_signed(5, sub.best.shift);
for (int i = 0; i < sub.best.order; i++)
bitwriter.writebits_signed(cbits, sub.best.coefs[i]);
// residual
output_residual(frame, bitwriter, sub);
}
unsafe uint measure_frame_size(FlacFrame frame, bool do_midside)
{
// crude estimation of header/footer size
uint total = (uint)(32 + ((BitReader.log2i(frame_count) + 4) / 5) * 8 + (eparams.variable_block_size != 0 ? 16 : 0) + 16);
if (do_midside)
{
uint bitsBest = AudioSamples.UINT32_MAX;
ChannelMode modeBest = ChannelMode.LeftRight;
if (bitsBest > frame.subframes[2].best.size + frame.subframes[3].best.size)
{
bitsBest = frame.subframes[2].best.size + frame.subframes[3].best.size;
modeBest = ChannelMode.MidSide;
}
if (bitsBest > frame.subframes[3].best.size + frame.subframes[1].best.size)
{
bitsBest = frame.subframes[3].best.size + frame.subframes[1].best.size;
modeBest = ChannelMode.RightSide;
}
if (bitsBest > frame.subframes[3].best.size + frame.subframes[0].best.size)
{
bitsBest = frame.subframes[3].best.size + frame.subframes[0].best.size;
modeBest = ChannelMode.LeftSide;
}
if (bitsBest > frame.subframes[0].best.size + frame.subframes[1].best.size)
{
bitsBest = frame.subframes[0].best.size + frame.subframes[1].best.size;
modeBest = ChannelMode.LeftRight;
}
frame.ch_mode = modeBest;
return total + bitsBest;
}
for (int ch = 0; ch < channels; ch++)
total += frame.subframes[ch].best.size;
return total;
}
unsafe void encode_residual_pass1(FlacFrame frame, int ch, int best_window)
{
int max_prediction_order = eparams.max_prediction_order;
int max_fixed_order = eparams.max_fixed_order;
int min_fixed_order = eparams.min_fixed_order;
int lpc_min_precision_search = eparams.lpc_min_precision_search;
int lpc_max_precision_search = eparams.lpc_max_precision_search;
int max_partition_order = eparams.max_partition_order;
int estimation_depth = eparams.estimation_depth;
eparams.min_fixed_order = 2;
eparams.max_fixed_order = 2;
eparams.lpc_min_precision_search = eparams.lpc_max_precision_search;
eparams.max_prediction_order = 8;
eparams.estimation_depth = 1;
encode_residual(frame, ch, eparams.prediction_type, OrderMethod.Akaike, 1, best_window);
eparams.min_fixed_order = min_fixed_order;
eparams.max_fixed_order = max_fixed_order;
eparams.max_prediction_order = max_prediction_order;
eparams.lpc_min_precision_search = lpc_min_precision_search;
eparams.lpc_max_precision_search = lpc_max_precision_search;
eparams.max_partition_order = max_partition_order;
eparams.estimation_depth = estimation_depth;
}
unsafe int encode_frame(out int size)
{
fixed (int* s = samplesBuffer, r = residualBuffer)
fixed (float* window = windowBuffer)
{
frame.InitSize(eparams.block_size, eparams.variable_block_size != 0);
if (frame.blocksize != _windowsize && frame.blocksize > 4)
{
_windowsize = frame.blocksize;
_windowcount = 0;
calculate_window(window, lpc.window_welch, WindowFunction.Welch);
calculate_window(window, lpc.window_tukey, WindowFunction.Tukey);
calculate_window(window, lpc.window_flattop, WindowFunction.Flattop);
calculate_window(window, lpc.window_hann, WindowFunction.Hann);
calculate_window(window, lpc.window_bartlett, WindowFunction.Bartlett);
if (_windowcount == 0)
throw new Exception("invalid windowfunction");
}
if (channels != 2 || frame.blocksize <= 32 || eparams.stereo_method == StereoMethod.Independent)
{
frame.window_buffer = window;
frame.current.residual = r + channels * Flake.MAX_BLOCKSIZE;
frame.ch_mode = channels != 2 ? ChannelMode.NotStereo : ChannelMode.LeftRight;
for (int ch = 0; ch < channels; ch++)
frame.subframes[ch].Init(s + ch * Flake.MAX_BLOCKSIZE, r + ch * Flake.MAX_BLOCKSIZE,
_pcm.BitsPerSample, get_wasted_bits(s + ch * Flake.MAX_BLOCKSIZE, frame.blocksize));
for (int ch = 0; ch < channels; ch++)
encode_residual_pass2(frame, ch);
}
else
{
//channel_decorrelation(s, s + Flake.MAX_BLOCKSIZE, s + 2 * Flake.MAX_BLOCKSIZE, s + 3 * Flake.MAX_BLOCKSIZE, frame.blocksize);
frame.window_buffer = window;
frame.current.residual = r + 4 * Flake.MAX_BLOCKSIZE;
for (int ch = 0; ch < 4; ch++)
frame.subframes[ch].Init(s + ch * Flake.MAX_BLOCKSIZE, r + ch * Flake.MAX_BLOCKSIZE,
_pcm.BitsPerSample + (ch == 3 ? 1 : 0), get_wasted_bits(s + ch * Flake.MAX_BLOCKSIZE, frame.blocksize));
//for (int ch = 0; ch < 4; ch++)
// for (int iWindow = 0; iWindow < _windowcount; iWindow++)
// frame.subframes[ch].lpc_ctx[iWindow].GetReflection(32, frame.subframes[ch].samples, frame.blocksize, frame.window_buffer + iWindow * Flake.MAX_BLOCKSIZE * 2);
estimate_frame(frame, true);
uint fs = measure_frame_size(frame, true);
if (0 != eparams.variable_block_size)
{
FlacFrame frame2 = new FlacFrame(channels * 2);
FlacFrame frame3 = new FlacFrame(channels * 2);
int tumbler = 1;
while ((frame.blocksize & 1) == 0 && frame.blocksize >= 1024)
{
frame2.InitSize(frame.blocksize / 2, true);
frame2.window_buffer = frame.window_buffer + frame.blocksize;
frame2.current.residual = r + tumbler * 5 * Flake.MAX_BLOCKSIZE;
for (int ch = 0; ch < 4; ch++)
frame2.subframes[ch].Init(frame.subframes[ch].samples, frame2.current.residual + (ch + 1) * frame2.blocksize,
frame.subframes[ch].obits + frame.subframes[ch].wbits, frame.subframes[ch].wbits);
estimate_frame(frame2, true);
uint fs2 = measure_frame_size(frame2, true);
uint fs3 = fs2;
if (eparams.variable_block_size == 2 || eparams.variable_block_size == 4)
{
frame3.InitSize(frame2.blocksize, true);
frame3.window_buffer = frame2.window_buffer;
frame3.current.residual = frame2.current.residual + 5 * frame2.blocksize;
for (int ch = 0; ch < 4; ch++)
frame3.subframes[ch].Init(frame2.subframes[ch].samples + frame2.blocksize, frame3.current.residual + (ch + 1) * frame3.blocksize,
frame.subframes[ch].obits + frame.subframes[ch].wbits, frame.subframes[ch].wbits);
estimate_frame(frame3, true);
fs3 = measure_frame_size(frame3, true);
}
if (fs2 + fs3 > fs)
break;
FlacFrame tmp = frame;
frame = frame2;
frame2 = tmp;
fs = fs2;
if (eparams.variable_block_size <= 2)
break;
tumbler = 1 - tumbler;
}
}
frame.ChooseSubframes();
encode_estimated_frame(frame);
}
BitWriter bitwriter = new BitWriter(frame_buffer, 0, max_frame_size);
output_frame_header(frame, bitwriter);
output_subframes(frame, bitwriter);
output_frame_footer(bitwriter);
if (bitwriter.Length >= max_frame_size)
throw new Exception("buffer overflow");
if (frame_buffer != null)
{
if (eparams.variable_block_size > 0)
frame_count += frame.blocksize;
else
frame_count++;
}
size = frame.blocksize;
return bitwriter.Length;
}
}
unsafe int estimate_best_window(FlacFrame frame, int ch)
{
if (_windowcount == 1)
return 0;
switch (eparams.window_method)
{
case WindowMethod.Estimate:
{
int best_window = -1;
double best_error = 0;
int order = 2;
for (int i = 0; i < _windowcount; i++)
{
frame.subframes[ch].lpc_ctx[i].GetReflection(order, frame.subframes[ch].samples, frame.blocksize, frame.window_buffer + i * Flake.MAX_BLOCKSIZE * 2);
double err = frame.subframes[ch].lpc_ctx[i].prediction_error[order - 1] / frame.subframes[ch].lpc_ctx[i].autocorr_values[0];
//double err = frame.subframes[ch].lpc_ctx[i].autocorr_values[0] / frame.subframes[ch].lpc_ctx[i].autocorr_values[2];
if (best_window == -1 || best_error > err)
{
best_window = i;
best_error = err;
}
}
return best_window;
}
case WindowMethod.Evaluate:
encode_residual_pass1(frame, ch, -1);
return frame.subframes[ch].best.type == SubframeType.LPC ? frame.subframes[ch].best.window : -1;
case WindowMethod.Search:
return -1;
}
return -1;
}
unsafe void encode_residual_fixed_sub(FlacFrame frame, int order, int ch)
{
if ((frame.subframes[ch].done_fixed & (1U << order)) != 0)
return; // already calculated;
frame.current.order = order;
frame.current.type = SubframeType.Fixed;
encode_residual_fixed(frame.current.residual, frame.subframes[ch].samples, frame.blocksize, frame.current.order);
int pmax = get_max_p_order(eparams.max_partition_order, frame.blocksize, frame.current.order);
int pmin = Math.Min(eparams.min_partition_order, pmax);
frame.current.size = (uint)(frame.current.order * frame.subframes[ch].obits) + 6
+ calc_rice_params(frame.current.rc, pmin, pmax, frame.current.residual, (uint)frame.blocksize, (uint)frame.current.order, PCM.BitsPerSample);
frame.subframes[ch].done_fixed |= (1U << order);
frame.ChooseBestSubframe(ch);
}
unsafe void estimate_frame(FlacFrame frame, bool do_midside)
{
int subframes = do_midside ? channels * 2 : channels;
switch (eparams.stereo_method)
{
case StereoMethod.Estimate:
for (int ch = 0; ch < subframes; ch++)
{
LpcContext lpc_ctx = frame.subframes[ch].lpc_ctx[0];
lpc_ctx.GetReflection(4, frame.subframes[ch].samples, frame.blocksize, frame.window_buffer);
lpc_ctx.SortOrdersAkaike(frame.blocksize, 1, 4, 4.5, 0.0);
frame.subframes[ch].best.size = (uint)Math.Max(0, lpc_ctx.Akaike(frame.blocksize, lpc_ctx.best_orders[0], 4.5, 0.0) + 7.1 * frame.subframes[ch].obits * eparams.max_prediction_order);
}
break;
case StereoMethod.Evaluate:
for (int ch = 0; ch < subframes; ch++)
encode_residual_pass1(frame, ch, 0);
break;
case StereoMethod.Search:
for (int ch = 0; ch < subframes; ch++)
encode_residual_pass2(frame, ch);
break;
}
}
unsafe void decode_subframe_verbatim(BitReader bitreader, FlacFrame frame, int ch)
{
int obits = frame.subframes[ch].obits;
for (int i = 0; i < frame.blocksize; i++)
frame.subframes[ch].best.residual[i] = bitreader.readbits_signed(obits);
}
unsafe void encode_estimated_frame(FlacFrame frame)
{
switch (eparams.stereo_method)
{
case StereoMethod.Estimate:
for (int ch = 0; ch < channels; ch++)
{
frame.subframes[ch].best.size = AudioSamples.UINT32_MAX;
encode_residual_pass2(frame, ch);
}
break;
case StereoMethod.Evaluate:
for (int ch = 0; ch < channels; ch++)
encode_residual_pass2(frame, ch);
break;
case StereoMethod.Search:
break;
}
}
unsafe void Restore_samples(FlacFrame frame)
{
for (int ch = 0; ch < PCM.ChannelCount; ch++)
{
switch (frame.subframes[ch].best.type)
{
case SubframeType.Constant:
AudioSamples.MemSet(frame.subframes[ch].samples, frame.subframes[ch].best.residual[0], frame.blocksize);
break;
case SubframeType.Verbatim:
AudioSamples.MemCpy(frame.subframes[ch].samples, frame.subframes[ch].best.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 *s = frame.subframes[ch].samples;
int x = (int)frame.subframes[ch].wbits;
for (int i = frame.blocksize; i > 0; i--)
{
*(s++) <<= x;
}
}
}
if (frame.ch_mode != ChannelMode.NotStereo)
{
int *l = frame.subframes[0].samples;
int *r = frame.subframes[1].samples;
switch (frame.ch_mode)
{
case ChannelMode.LeftRight:
break;
case ChannelMode.MidSide:
for (int i = frame.blocksize; i > 0; i--)
{
int mid = *l;
int side = *r;
mid <<= 1;
mid |= (side & 1); /* i.e. if 'side' is odd... */
*(l++) = (mid + side) >> 1;
*(r++) = (mid - side) >> 1;
}
break;
case ChannelMode.LeftSide:
for (int i = frame.blocksize; i > 0; i--)
{
int _l = *(l++), _r = *r;
*(r++) = _l - _r;
}
break;
case ChannelMode.RightSide:
for (int i = frame.blocksize; i > 0; i--)
{
*(l++) += *(r++);
}
break;
}
}
}
unsafe void encode_residual_lpc_sub(FlacFrame frame, float* lpcs, int iWindow, int order, int ch)
{
// select LPC precision based on block size
uint lpc_precision;
if (frame.blocksize <= 192) lpc_precision = 7U;
else if (frame.blocksize <= 384) lpc_precision = 8U;
else if (frame.blocksize <= 576) lpc_precision = 9U;
else if (frame.blocksize <= 1152) lpc_precision = 10U;
else if (frame.blocksize <= 2304) lpc_precision = 11U;
else if (frame.blocksize <= 4608) lpc_precision = 12U;
else if (frame.blocksize <= 8192) lpc_precision = 13U;
else if (frame.blocksize <= 16384) lpc_precision = 14U;
else lpc_precision = 15;
for (int i_precision = eparams.lpc_min_precision_search; i_precision <= eparams.lpc_max_precision_search && lpc_precision + i_precision < 16; i_precision++)
// check if we already calculated with this order, window and precision
if ((frame.subframes[ch].lpc_ctx[iWindow].done_lpcs[i_precision] & (1U << (order - 1))) == 0)
{
frame.subframes[ch].lpc_ctx[iWindow].done_lpcs[i_precision] |= (1U << (order - 1));
uint cbits = lpc_precision + (uint)i_precision;
frame.current.type = SubframeType.LPC;
frame.current.order = order;
frame.current.window = iWindow;
fixed (int* coefs = frame.current.coefs)
{
lpc.quantize_lpc_coefs(lpcs + (frame.current.order - 1) * lpc.MAX_LPC_ORDER,
frame.current.order, cbits, coefs, out frame.current.shift, 15, 0);
if (frame.current.shift < 0 || frame.current.shift > 15)
throw new Exception("negative shift");
ulong csum = 0;
for (int i = frame.current.order; i > 0; i--)
csum += (ulong)Math.Abs(coefs[i - 1]);
if ((csum << frame.subframes[ch].obits) >= 1UL << 32)
lpc.encode_residual_long(frame.current.residual, frame.subframes[ch].samples, frame.blocksize, frame.current.order, coefs, frame.current.shift);
else
lpc.encode_residual(frame.current.residual, frame.subframes[ch].samples, frame.blocksize, frame.current.order, coefs, frame.current.shift);
}
int pmax = get_max_p_order(eparams.max_partition_order, frame.blocksize, frame.current.order);
int pmin = Math.Min(eparams.min_partition_order, pmax);
uint best_size = calc_rice_params(frame.current.rc, pmin, pmax, frame.current.residual, (uint)frame.blocksize, (uint)frame.current.order, PCM.BitsPerSample);
// not working
//for (int o = 1; o <= frame.current.order; o++)
//{
// if (frame.current.coefs[o - 1] > -(1 << frame.current.shift))
// {
// for (int i = o; i < frame.blocksize; i++)
// frame.current.residual[i] += frame.subframes[ch].samples[i - o] >> frame.current.shift;
// frame.current.coefs[o - 1]--;
// uint new_size = calc_rice_params(ref frame.current.rc, pmin, pmax, frame.current.residual, (uint)frame.blocksize, (uint)frame.current.order);
// if (new_size > best_size)
// {
// for (int i = o; i < frame.blocksize; i++)
// frame.current.residual[i] -= frame.subframes[ch].samples[i - o] >> frame.current.shift;
// frame.current.coefs[o - 1]++;
// }
// }
//}
frame.current.size = (uint)(frame.current.order * frame.subframes[ch].obits + 4 + 5 + frame.current.order * (int)cbits + 6 + (int)best_size);
frame.ChooseBestSubframe(ch);
}
}
public FlakeWriter(Stream IO, FlakeWriterSettings settings)
{
m_settings = settings;
//if (Settings.PCM.BitsPerSample != 16)
// throw new Exception("Bits per sample must be 16.");
//if (Settings.PCM.ChannelCount != 2)
// throw new Exception("ChannelCount must be 2.");
channels = Settings.PCM.ChannelCount;
// flake_validate_params
//_path = path;
if (IO == null)
{
throw new ArgumentNullException("IO");
}
_IO = IO;
samplesBuffer = new int[Flake.MAX_BLOCKSIZE * (channels == 2 ? 4 : channels)];
residualBuffer = new int[Flake.MAX_BLOCKSIZE * (channels == 2 ? 10 : channels + 1)];
windowBuffer = new float[Flake.MAX_BLOCKSIZE * 2 * lpc.MAX_LPC_WINDOWS];
windowScale = new double[lpc.MAX_LPC_WINDOWS];
var _compressionLevel = Settings.EncoderModeIndex;
eparams.flake_set_defaults(_compressionLevel);
crc8 = new Crc8();
frame = new FlacFrame(channels * 2);
}
unsafe void encode_residual(FlacFrame frame, int ch, PredictionType predict, OrderMethod omethod, int pass, int best_window)
{
int* smp = frame.subframes[ch].samples;
int i, n = frame.blocksize;
// save best.window, because we can overwrite it later with fixed frame
// CONSTANT
for (i = 1; i < n; i++)
{
if (smp[i] != smp[0]) break;
}
if (i == n)
{
frame.subframes[ch].best.type = SubframeType.Constant;
frame.subframes[ch].best.residual[0] = smp[0];
frame.subframes[ch].best.size = (uint)frame.subframes[ch].obits;
return;
}
// VERBATIM
frame.current.type = SubframeType.Verbatim;
frame.current.size = (uint)(frame.subframes[ch].obits * frame.blocksize);
frame.ChooseBestSubframe(ch);
if (n < 5 || predict == PredictionType.None)
return;
// FIXED
if (predict == PredictionType.Fixed ||
(predict == PredictionType.Search && pass != 1) ||
//predict == PredictionType.Search ||
//(pass == 2 && frame.subframes[ch].best.type == SubframeType.Fixed) ||
n <= eparams.max_prediction_order)
{
int max_fixed_order = Math.Min(eparams.max_fixed_order, 4);
int min_fixed_order = Math.Min(eparams.min_fixed_order, max_fixed_order);
for (i = min_fixed_order; i <= max_fixed_order; i++)
encode_residual_fixed_sub(frame, i, ch);
}
// LPC
if (n > eparams.max_prediction_order &&
(predict == PredictionType.Levinson ||
predict == PredictionType.Search)
//predict == PredictionType.Search ||
//(pass == 2 && frame.subframes[ch].best.type == SubframeType.LPC))
)
{
float* lpcs = stackalloc float[lpc.MAX_LPC_ORDER * lpc.MAX_LPC_ORDER];
int min_order = eparams.min_prediction_order;
int max_order = eparams.max_prediction_order;
for (int iWindow = 0; iWindow < _windowcount; iWindow++)
{
if (best_window != -1 && iWindow != best_window)
continue;
LpcContext lpc_ctx = frame.subframes[ch].lpc_ctx[iWindow];
lpc_ctx.GetReflection(max_order, smp, n, frame.window_buffer + iWindow * Flake.MAX_BLOCKSIZE * 2);
lpc_ctx.ComputeLPC(lpcs);
//int frameSize = n;
//float* F = stackalloc float[frameSize];
//float* B = stackalloc float[frameSize];
//float* PE = stackalloc float[max_order + 1];
//float* arp = stackalloc float[max_order];
//float* rc = stackalloc float[max_order];
//for (int j = 0; j < frameSize; j++)
// F[j] = B[j] = smp[j];
//for (int K = 1; K <= max_order; K++)
//{
// // BURG:
// float denominator = 0.0f;
// //float denominator = F[K - 1] * F[K - 1] + B[frameSize - K] * B[frameSize - K];
// for (int j = 0; j < frameSize - K; j++)
// denominator += F[j + K] * F[j + K] + B[j] * B[j];
// denominator /= 2;
// // Estimate error
// PE[K - 1] = denominator / (frameSize - K);
// float reflectionCoeff = 0.0f;
// for (int j = 0; j < frameSize - K; j++)
// reflectionCoeff += F[j + K] * B[j];
// reflectionCoeff /= denominator;
// rc[K - 1] = arp[K - 1] = reflectionCoeff;
// // Levinson-Durbin
// for (int j = 0; j < (K - 1) >> 1; j++)
// {
// float arptmp = arp[j];
// arp[j] -= reflectionCoeff * arp[K - 2 - j];
// arp[K - 2 - j] -= reflectionCoeff * arptmp;
// }
// if (((K - 1) & 1) != 0)
// arp[(K - 1) >> 1] -= reflectionCoeff * arp[(K - 1) >> 1];
// for (int j = 0; j < frameSize - K; j++)
// {
// float f = F[j + K];
// float b = B[j];
// F[j + K] = f - reflectionCoeff * b;
// B[j] = b - reflectionCoeff * f;
// }
// for (int j = 0; j < K; j++)
// lpcs[(K - 1) * lpc.MAX_LPC_ORDER + j] = (float)arp[j];
//}
switch (omethod)
{
case OrderMethod.Akaike:
//lpc_ctx.SortOrdersAkaike(frame.blocksize, eparams.estimation_depth, max_order, 7.1, 0.0);
lpc_ctx.SortOrdersAkaike(frame.blocksize, eparams.estimation_depth, max_order, 4.5, 0.0);
break;
default:
throw new Exception("unknown order method");
}
for (i = 0; i < eparams.estimation_depth && i < max_order; i++)
encode_residual_lpc_sub(frame, lpcs, iWindow, lpc_ctx.best_orders[i], ch);
}
}
}
unsafe void encode_residual_pass1(FlacFrame frame, int ch, int best_window)
{
int max_prediction_order = eparams.max_prediction_order;
int max_fixed_order = eparams.max_fixed_order;
int min_fixed_order = eparams.min_fixed_order;
int lpc_min_precision_search = eparams.lpc_min_precision_search;
int lpc_max_precision_search = eparams.lpc_max_precision_search;
int max_partition_order = eparams.max_partition_order;
int estimation_depth = eparams.estimation_depth;
var development_mode = eparams.development_mode;
eparams.min_fixed_order = 2;
eparams.max_fixed_order = 2;
eparams.lpc_min_precision_search = eparams.lpc_max_precision_search;
eparams.max_prediction_order = Math.Min(eparams.max_prediction_order, Math.Max(eparams.min_prediction_order, 8));
eparams.estimation_depth = 1;
eparams.development_mode = Math.Min(eparams.development_mode, -1);
encode_residual(frame, ch, eparams.prediction_type, OrderMethod.Akaike, 1, best_window);
eparams.min_fixed_order = min_fixed_order;
eparams.max_fixed_order = max_fixed_order;
eparams.max_prediction_order = max_prediction_order;
eparams.lpc_min_precision_search = lpc_min_precision_search;
eparams.lpc_max_precision_search = lpc_max_precision_search;
eparams.max_partition_order = max_partition_order;
eparams.estimation_depth = estimation_depth;
eparams.development_mode = development_mode;
}
