private IEnumerable <int> GetPredictorSamples(int blockSize, int[] warmupSamples, IPredictor predictor, IEnumerator <int> residualData)
{
int lastSample = 0;
if (warmupSamples.Length > 0)
{
for (int i = 0; i < warmupSamples.Length; i++)
{
yield return(warmupSamples[i]);
}
lastSample = warmupSamples[warmupSamples.Length - 1];
}
for (int i = warmupSamples.Length; i < blockSize; i++)
{
if (!residualData.MoveNext())
{
throw new FlacException("Not enough residual data");
}
int x = predictor.Next(lastSample);
int e = residualData.Current;
int nextSample = x + e;
yield return(nextSample);
lastSample = nextSample;
}
if (residualData.MoveNext())
{
throw new FlacException("Not all residual data is decoded");
}
}
private IEnumerator<int> GetResidual(int[] samples, int predictorOrder, IPredictor predictor)
{
int lastSample = predictorOrder > 0 ? samples[predictorOrder - 1] : 0;
for (int i = predictorOrder; i < samples.Length; i++)
{
int nextSample = samples[i];
yield return nextSample - predictor.Next(lastSample);
lastSample = nextSample;
}
}
private IEnumerator <int> GetResidual(int[] samples, int predictorOrder, IPredictor predictor)
{
int lastSample = predictorOrder > 0 ? samples[predictorOrder - 1] : 0;
for (int i = predictorOrder; i < samples.Length; i++)
{
int nextSample = samples[i];
yield return(nextSample - predictor.Next(lastSample));
lastSample = nextSample;
}
}
private IEnumerable<int> GetPredictorSamples(int blockSize, int[] warmupSamples, IPredictor predictor, IEnumerator<int> residualData)
{
int lastSample = 0;
if (warmupSamples.Length > 0)
{
for (int i = 0; i < warmupSamples.Length; i++)
{
yield return warmupSamples[i];
}
lastSample = warmupSamples[warmupSamples.Length - 1];
}
for (int i = warmupSamples.Length; i < blockSize; i++)
{
if (!residualData.MoveNext())
throw new FlacException("Not enough residual data");
int x = predictor.Next(lastSample);
int e = residualData.Current;
int nextSample = x + e;
yield return nextSample;
lastSample = nextSample;
}
if (residualData.MoveNext())
throw new FlacException("Not all residual data is decoded");
}
public int Next(int x)
{
return(basePredictor.Next(x) << shift);
}
private FlacResidualCoefficeints FindBestResidual(int[] channelSamples, int order, IPredictor predictor, FlacEncodingPolicy policy)
{
int[] residual;
if (order > 0)
{
residual = new int[channelSamples.Length];
int lastSample = channelSamples[order - 1];
for (int i = order; i < residual.Length; i++)
{
int nextSample = channelSamples[i];
residual[i] = nextSample - predictor.Next(lastSample);
lastSample = nextSample;
}
}
else
{
residual = channelSamples;
}
int minRiceOrder = policy.RicePartionOrder.MinValue;
int maxRiceOrder = policy.RicePartionOrder.MaxValue;
List <FlacResidualCoefficeints> rices = new List <FlacResidualCoefficeints>();
int samplesPerPartition = channelSamples.Length >> minRiceOrder;
if (samplesPerPartition << minRiceOrder != channelSamples.Length)
{
minRiceOrder = maxRiceOrder = 0; // reset minRiceOrder to zero;
}
for (int riceOrder = minRiceOrder; riceOrder <= maxRiceOrder; riceOrder++)
{
if (samplesPerPartition <= order)
{
break;
}
int partitionCount = 1 << riceOrder;
int[] parameters = new int[partitionCount];
int totalPartitionDataSize = 0;
int j = order;
for (int i = 0; i < partitionCount; i++)
{
int skipAmount = i == 0 ? order : 0;
int estimatedPartitionSize;
int riceParameter;
FindBestResidual(residual, samplesPerPartition * i + skipAmount, samplesPerPartition - skipAmount,
out estimatedPartitionSize, out riceParameter);
totalPartitionDataSize += estimatedPartitionSize;
parameters[i] = riceParameter;
}
const int NormalPrecision = 4;
const int ExtendedPrecision = 5;
const int MinValueForExtendedParameters = 15;
bool isExtended = false;
for (int i = 0; i < parameters.Length && !isExtended; ++i)
{
isExtended = parameters[i] >= MinValueForExtendedParameters;
}
int totalSize = 4 + totalPartitionDataSize +
partitionCount * (isExtended ? ExtendedPrecision : NormalPrecision);
FlacResidualCoefficeints rice = new FlacResidualCoefficeints();
rice.EstimatedSize = totalSize;
rice.IsExtended = isExtended;
rice.RiceParameters = parameters;
rice.Order = riceOrder;
rices.Add(rice);
if ((samplesPerPartition & 1) != 0)
{
break;
}
samplesPerPartition >>= 1;
}
int bestRicePartition = 0;
for (int i = 1; i < rices.Count; i++)
{
if (rices[bestRicePartition].EstimatedSize > rices[i].EstimatedSize)
{
bestRicePartition = i;
}
}
return(rices[bestRicePartition]);
}
private FlacResidualCoefficeints FindBestResidual(int[] channelSamples, int order, IPredictor predictor, FlacEncodingPolicy policy)
{
int[] residual;
if (order > 0)
{
residual = new int[channelSamples.Length];
int lastSample = channelSamples[order - 1];
for (int i = order; i < residual.Length; i++)
{
int nextSample = channelSamples[i];
residual[i] = nextSample - predictor.Next(lastSample);
lastSample = nextSample;
}
}
else
residual = channelSamples;
int minRiceOrder = policy.RicePartionOrder.MinValue;
int maxRiceOrder = policy.RicePartionOrder.MaxValue;
List<FlacResidualCoefficeints> rices = new List<FlacResidualCoefficeints>();
int samplesPerPartition = channelSamples.Length >> minRiceOrder;
if (samplesPerPartition << minRiceOrder != channelSamples.Length)
{
minRiceOrder = maxRiceOrder = 0; // reset minRiceOrder to zero;
}
for (int riceOrder = minRiceOrder; riceOrder <= maxRiceOrder; riceOrder++)
{
if (samplesPerPartition <= order) break;
int partitionCount = 1 << riceOrder;
int[] parameters = new int[partitionCount];
int totalPartitionDataSize = 0;
int j = order;
for (int i = 0; i < partitionCount; i++)
{
int skipAmount = i == 0 ? order : 0;
int estimatedPartitionSize;
int riceParameter;
FindBestResidual(residual, samplesPerPartition * i + skipAmount, samplesPerPartition - skipAmount,
out estimatedPartitionSize, out riceParameter);
totalPartitionDataSize += estimatedPartitionSize;
parameters[i] = riceParameter;
}
const int NormalPrecision = 4;
const int ExtendedPrecision = 5;
const int MinValueForExtendedParameters = 15;
bool isExtended = Array.Exists(parameters, delegate(int x) {
return x >= MinValueForExtendedParameters;
});
int totalSize = 4 + totalPartitionDataSize +
partitionCount * (isExtended ? ExtendedPrecision : NormalPrecision);
FlacResidualCoefficeints rice = new FlacResidualCoefficeints();
rice.EstimatedSize = totalSize;
rice.IsExtended = isExtended;
rice.RiceParameters = parameters;
rice.Order = riceOrder;
rices.Add(rice);
if ((samplesPerPartition & 1) != 0) break;
samplesPerPartition >>= 1;
}
int bestRicePartition = 0;
for (int i = 1; i < rices.Count; i++)
{
if (rices[bestRicePartition].EstimatedSize > rices[i].EstimatedSize)
bestRicePartition = i;
}
return rices[bestRicePartition];
}