package micromod.resamplers;
/**
The Resampler interface specifies a pure resampling algorithm.
The algorithm need not maintain any state between invocations,
making implementations of resamplers far more straight-forward.
As an added advantage, the resampling loop (where most of the
cpu time is spent) can be made tighter. Since an implementation
need not have to maintain a state, a single instance of a Resampler
can be used for all channels, and this may be switched on the fly.
*/
public interface Resampler {
public static final int FIXED_POINT_SHIFT=16;
public static final int FIXED_POINT_ONE=1<<FIXED_POINT_SHIFT;
public static final int FIXED_POINT_BITMASK=FIXED_POINT_ONE-1;
/**
Resample the audio in inputBuf to outputBuf.
The resampler should be able to deal correctly with a length of at least 1.
@param samplePos The index of the sample in inputBuf
@param subSamplePos The fractional part of the index, in 16 bit fixed point.
@param step The integer part of the number of input samples per output sample.
@param subStep The fractional part of the number of input samples per output sample.
The value is in 16 bit fixed point.
@param position The index of the output buffer to start writing to.
@param length The number of samples of output to produce.
*/
public void resample( short[] inputBuf, int samplePos, int subSamplePos, int step, int subStep,
short[] outputBuf, int position, int length );
/**
Return minimum number of samples required by the resampler before and after the audio
to be processed. A cubic resampler might return 3, for example.
*/
public int getCushionSize();
}
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