internal override FlacMethodAndDataPair[] FindBestMethods(int[][] samples, int bitsPerSamples)
{
FlacMethodAndDataPair[] samplesAndMethods = new FlacMethodAndDataPair[samples.Length];
parallel.For(0, samples.Length, i =>
{
samplesAndMethods[i] = new FlacMethodAndDataPair(
FindBestMethod(samples[i], bitsPerSamples),
bitsPerSamples,
samples[i]);
});
return(samplesAndMethods);
}
private void WriteSubframe(FlacBitStreamWriter bitWriter, FlacMethodAndDataPair flacMethodAndDataPair)
{
bitWriter.WriteUnsigned(0, 1);
int subframeType = flacMethodAndDataPair.Method.SubframeTypeCode;
bitWriter.WriteUnsigned((uint)subframeType, 6);
bitWriter.WriteUnsigned(0, 1);
flacMethodAndDataPair.WriteData(bitWriter);
}
internal override FlacMethodAndDataPair[] FindBestMethods(int[][] samples, int bitsPerSamples)
{
FlacMethodAndDataPair[] samplesAndMethods = new FlacMethodAndDataPair[samples.Length];
parallel.For(0, samples.Length, i =>
{
samplesAndMethods[i] = new FlacMethodAndDataPair(
FindBestMethod(samples[i], bitsPerSamples),
bitsPerSamples,
samples[i]);
});
return samplesAndMethods;
}
private void WriteSubframe(FlacBitStreamWriter bitWriter, FlacMethodAndDataPair flacMethodAndDataPair)
{
bitWriter.WriteUnsigned(0, 1);
int subframeType = flacMethodAndDataPair.Method.SubframeTypeCode;
bitWriter.WriteUnsigned((uint)subframeType, 6);
bitWriter.WriteUnsigned(0, 1);
flacMethodAndDataPair.WriteData(bitWriter);
}
public void WriteFrame(FlacMethodAndDataPair[] methods, SoundChannelAssignmentType channelAssignment)
{
EnsureFramesMode();
sink.StartFrame(streamPosition, currentSample);
if (methods == null) throw new ArgumentNullException("methods");
if(methods.Length != Streaminfo.ChannelsCount)
throw new ArgumentNullException("Methods items does not correspond to amount of channels");
int samplesCount = methods[0].Data.Length;
const byte Blocking = 0x00; // fixed
MemoryStream frameHeader = new MemoryStream();
// sync code + reserved = 0 + blocking
frameHeader.WriteByte(0xFF); frameHeader.WriteByte(0xF8 | Blocking);
int interChannelSamplesTypeIndex = Array.IndexOf(FlacCommons.StaticBlockSizeSamples, samplesCount);
int interChannelSamplesType;
if (interChannelSamplesTypeIndex > 0)
interChannelSamplesType = interChannelSamplesTypeIndex;
else if (samplesCount > 256)
interChannelSamplesType = FlacCommons.Bit16BlockSizeSamplesType;
else
interChannelSamplesType = FlacCommons.Bit8BlockSizeSamplesType;
int sampleRateTypeIndex = Array.IndexOf(FlacCommons.StaticSampleRates, Streaminfo.SampleRate);
int sampleRateType = sampleRateTypeIndex > 0
? sampleRateTypeIndex : FlacCommons.StreaminfoSampleRateType;
frameHeader.WriteByte((byte)(interChannelSamplesType << 4 | sampleRateType));
int channelAssignmetType = (int)channelAssignment;
int sampleSizeInBitsTypeIndex = Array.IndexOf(FlacCommons.StaticSampleSizeInBits, Streaminfo.BitsPerSample);
int sampleSizeInBitsType = sampleSizeInBitsTypeIndex > 0
? sampleSizeInBitsTypeIndex : FlacCommons.StreaminfoSizeInBitsType;
frameHeader.WriteByte((byte)(channelAssignmetType << 4 | sampleSizeInBitsType << 1));
WriteUtf8Number(frameHeader, frameNumber);
switch (interChannelSamplesType)
{
case FlacCommons.Bit8BlockSizeSamplesType:
frameHeader.WriteByte((byte)(samplesCount - 1)); break;
case FlacCommons.Bit16BlockSizeSamplesType:
frameHeader.WriteByte((byte)((samplesCount - 1) >> 8));
frameHeader.WriteByte((byte)(samplesCount - 1));
break;
}
frameHeader.Close();
byte[] frameHeaderData = frameHeader.ToArray();
byte crc8 = CrcUtils.Crc8(0, frameHeaderData);
BaseStream.Write(frameHeaderData, 0, frameHeaderData.Length);
BaseStream.WriteByte(crc8);
++frameNumber;
ushort crc16Seed = CrcUtils.Crc16(CrcUtils.Crc16(0, frameHeaderData), crc8);
// write channels
FlacBitStreamWriter bitWriter = new FlacBitStreamWriter(BaseStream, crc16Seed);
for (int i = 0; i < methods.Length; i++)
{
WriteSubframe(bitWriter, methods[i]);
}
int subframesLength;
ushort crc16;
bitWriter.Complete(out crc16, out subframesLength);
// write footer
BaseStream.WriteByte((byte)(crc16 >> 8)); BaseStream.WriteByte((byte)crc16);
int frameSize = frameHeaderData.Length + 1 + subframesLength + 2;
streamPosition += frameSize;
currentSample += samplesCount;
sink.EndFrame(streamPosition, currentSample);
}
public SoundChannelAssignmentType FindBestMethod(int[] leftSamples, int[] rightSamples, out FlacMethodAndDataPair[] methods)
{
if (leftSamples == null) throw new ArgumentNullException("leftSamples");
if (rightSamples == null) throw new ArgumentNullException("rightSamples");
if (leftSamples.Length != rightSamples.Length)
throw new ArgumentException("leftSamples and rightSamples has to have same amount of samples");
if(leftSamples.Length == 0)
throw new ArgumentException("channels has to have at least one item");
return estimator.FindBestMethods(leftSamples, rightSamples, Streaminfo.BitsPerSample,
out methods);
}
internal override SoundChannelAssignmentType FindBestMethods(int[] leftSamples, int[] rightSamples, int bitsPerSample, out FlacMethodAndDataPair[] methods)
{
if (policy.StereoEncoding == StereoEncodingPolicy.AsIs)
{
methods = FindBestMethods(new int[2][] { leftSamples, rightSamples }, bitsPerSample);
return(SoundChannelAssignmentType.LeftRight);
}
int samplesPerChannel = leftSamples.Length;
int[] differenceLeftMinusRight = null, average = null;
FlacMethod methodForLeft = null, methodForRight = null, methodForSide = null, methodForAverage = null;
parallel.Invoke(
delegate
{
methodForLeft = FindBestMethod(leftSamples, bitsPerSample);
},
delegate
{
methodForRight = FindBestMethod(rightSamples, bitsPerSample);
},
delegate
{
differenceLeftMinusRight = new int[samplesPerChannel];
for (int i = 0; i < samplesPerChannel; i++)
{
differenceLeftMinusRight[i] = leftSamples[i] - rightSamples[i];
}
methodForSide = FindBestMethod(differenceLeftMinusRight, bitsPerSample + 1);
},
delegate
{
if (policy.StereoEncoding == StereoEncodingPolicy.TrySidesAndAverage)
{
average = new int[samplesPerChannel];
for (int i = 0; i < samplesPerChannel; i++)
{
average[i] = (leftSamples[i] + rightSamples[i]) >> 1;
}
methodForAverage = FindBestMethod(average, bitsPerSample);
}
}
);
int independentEstimation = methodForLeft.EstimatedSize + methodForRight.EstimatedSize;
int leftSideEstimation = methodForLeft.EstimatedSize + methodForSide.EstimatedSize;
int rightSideEstimation = methodForSide.EstimatedSize + methodForRight.EstimatedSize;
int averageEstimation = average == null ? int.MaxValue :
methodForAverage.EstimatedSize + methodForSide.EstimatedSize;
SoundChannelAssignmentType type;
if (Math.Min(independentEstimation, leftSideEstimation) < Math.Min(rightSideEstimation, averageEstimation))
{
if (independentEstimation <= leftSideEstimation)
{
type = SoundChannelAssignmentType.LeftRight;
methods = new FlacMethodAndDataPair[] {
new FlacMethodAndDataPair(methodForLeft, bitsPerSample, leftSamples),
new FlacMethodAndDataPair(methodForRight, bitsPerSample, rightSamples)
};
}
else
{
type = SoundChannelAssignmentType.LeftSide;
methods = new FlacMethodAndDataPair[] {
new FlacMethodAndDataPair(methodForLeft, bitsPerSample, leftSamples),
new FlacMethodAndDataPair(methodForSide, bitsPerSample + 1, differenceLeftMinusRight)
};
}
}
else
{
if (rightSideEstimation <= averageEstimation)
{
type = SoundChannelAssignmentType.RightSide;
methods = new FlacMethodAndDataPair[] {
new FlacMethodAndDataPair(methodForSide, bitsPerSample + 1, differenceLeftMinusRight),
new FlacMethodAndDataPair(methodForRight, bitsPerSample, rightSamples)
};
}
else
{
type = SoundChannelAssignmentType.MidSide;
methods = new FlacMethodAndDataPair[] {
new FlacMethodAndDataPair(methodForAverage, bitsPerSample, average),
new FlacMethodAndDataPair(methodForSide, bitsPerSample + 1, differenceLeftMinusRight)
};
}
}
return(type);
}
internal override SoundChannelAssignmentType FindBestMethods(int[] leftSamples, int[] rightSamples, int bitsPerSample, out FlacMethodAndDataPair[] methods)
{
if (policy.StereoEncoding == StereoEncodingPolicy.AsIs)
{
methods = FindBestMethods(new int[2][] { leftSamples, rightSamples }, bitsPerSample);
return SoundChannelAssignmentType.LeftRight;
}
int samplesPerChannel = leftSamples.Length;
int[] differenceLeftMinusRight = null, average = null;
FlacMethod methodForLeft = null, methodForRight = null, methodForSide = null, methodForAverage = null;
parallel.Invoke(
delegate
{
methodForLeft = FindBestMethod(leftSamples, bitsPerSample);
},
delegate
{
methodForRight = FindBestMethod(rightSamples, bitsPerSample);
},
delegate
{
differenceLeftMinusRight = new int[samplesPerChannel];
for (int i = 0; i < samplesPerChannel; i++)
{
differenceLeftMinusRight[i] = leftSamples[i] - rightSamples[i];
}
methodForSide = FindBestMethod(differenceLeftMinusRight, bitsPerSample + 1);
},
delegate
{
if (policy.StereoEncoding == StereoEncodingPolicy.TrySidesAndAverage)
{
average = new int[samplesPerChannel];
for (int i = 0; i < samplesPerChannel; i++)
{
average[i] = (leftSamples[i] + rightSamples[i]) >> 1;
}
methodForAverage = FindBestMethod(average, bitsPerSample);
}
}
);
int independentEstimation = methodForLeft.EstimatedSize + methodForRight.EstimatedSize;
int leftSideEstimation = methodForLeft.EstimatedSize + methodForSide.EstimatedSize;
int rightSideEstimation = methodForSide.EstimatedSize + methodForRight.EstimatedSize;
int averageEstimation = average == null ? int.MaxValue :
methodForAverage.EstimatedSize + methodForSide.EstimatedSize;
SoundChannelAssignmentType type;
if (Math.Min(independentEstimation, leftSideEstimation) < Math.Min(rightSideEstimation, averageEstimation))
{
if (independentEstimation <= leftSideEstimation)
{
type = SoundChannelAssignmentType.LeftRight;
methods = new FlacMethodAndDataPair[] {
new FlacMethodAndDataPair(methodForLeft, bitsPerSample, leftSamples),
new FlacMethodAndDataPair(methodForRight, bitsPerSample, rightSamples)
};
}
else
{
type = SoundChannelAssignmentType.LeftSide;
methods = new FlacMethodAndDataPair[] {
new FlacMethodAndDataPair(methodForLeft, bitsPerSample, leftSamples),
new FlacMethodAndDataPair(methodForSide, bitsPerSample + 1, differenceLeftMinusRight)
};
}
}
else
{
if (rightSideEstimation <= averageEstimation)
{
type = SoundChannelAssignmentType.RightSide;
methods = new FlacMethodAndDataPair[] {
new FlacMethodAndDataPair(methodForSide, bitsPerSample + 1, differenceLeftMinusRight),
new FlacMethodAndDataPair(methodForRight, bitsPerSample, rightSamples)
};
}
else
{
type = SoundChannelAssignmentType.MidSide;
methods = new FlacMethodAndDataPair[] {
new FlacMethodAndDataPair(methodForAverage, bitsPerSample, average),
new FlacMethodAndDataPair(methodForSide, bitsPerSample + 1, differenceLeftMinusRight)
};
}
}
return type;
}
internal abstract SoundChannelAssignmentType FindBestMethods(int[] leftSamples, int[] rightSamples, int bitsPerSample, out FlacMethodAndDataPair[] methods);
