Implements an audio delay effect as a Media Foundation transform (MFT).
Demonstrates how to write an audio MFT.
This MFT is a 1-input, 1-output transform with fixed streams. It accepts any PCM audio type. The input and output formats must be identical.
The MFT maintains a circular buffer of the last N audio samples that were received as input. To produce the output data, each input sample is mixed with the next sample on the circular buffer. The percentage of each sample in the output is the "wet/dry" mix:
output_sample = (1.0 - wet) * input_sample + wet * delay_sample
where "wet" ranges [0..1]
The length of the buffer determines the length of the delay. If the client drains the MFT, the MFT produces an "effect tail," which is the trailing end of the delay effect.
The application can set the delay length and the wet/dry mix using the following attributes:
This sample requires Windows Vista or later.
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