Name
Splice -- perform the equivalent of a cross-faded tape splice
Synopsis
splice [-h|-t|-q] { position(=)[,excess[,leeway]] }
Function
Splice together audio sections. This effect provides two things over simple audio concatenation: a (usually short) cross-fade is applied at the join, and a wave similarity comparison is made to help determine the best place at which to make the join.

One of the options -h, -t, or -q may be given to select the fade envelope as half-cosine wave (the default), triangular (a.k.a. linear), or quarter-cosine wave respectively.

t
Audio: correlated. Fade level: constant gain. Transitions: abrupt.

h
Audio: correlated. Fade level: constant gain. Transitions: smooth.

q
Audio: uncorrelated. Fade level: constant power. Transitions: smooth.

To perform a splice, first use the trim effect to select the audio sections to be joined together. As when performing a tape splice, the end of the section to be spliced onto should be trimmed with a small excess (default 0.005 seconds) of audio after the ideal joining point. The beginning of the audio section to splice on should be trimmed with the same excess (before the ideal joining point), plus an additional leeway (default 0.005 seconds). Any time specification may be used for these parameters. The sound processor should then be invoked with the two audio sections as input samples and the splice effect given with the position at which to perform the splice - this is length of the first audio section (including the excess).

It is also possible to use this effect to perform general crossfades, e.g. to join two songs. In this case, excess would typically be a number of seconds, the -q option would typically be given (to select an "equal power" cross-fade), and leeway should be zero (which is the default if -q is given).

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