Extra buffer metadata describing how much audio has to be clipped from the start or end of a buffer.
This is used for compressed formats, where the first frame usually has some additional samples due to encoder and decoder delays, and the last frame usually has some additional samples to be able to fill the complete last frame.
This is used to ensure that decoded data in the end has the same amount of samples, and multiply decoded streams can be gaplessly concatenated.
Note: If clipping of the start is done by adjusting the segment, this meta has to be dropped from buffers as otherwise clipping could happen twice.