Video can be accessed and manipulated fairly extensively in the current runtime system, but it lacks support for processing audio. There is no easy way of replacing or adding audio from another source, or performing any kind of audio processing at runtime.
Put differently, any audio processing that is attempted is ignored, because audio outputs from ScriptClip() and ConditionalSelect() are ignored (effectively, audio from
last is used instead). ConditionalFilter() can take audio from a clip other than
last, but because it cannot access variables defined and/or modified at runtime it is a less than ideal solution. In addition, care needs to be taken because unlike with ScriptClip(), with ConditionalFilter() output clip length is not invariant - ConditionalFilter() can inadvertently modify output clip length.
Therefore, for its existing video processing support, read/write access to runtime variables and output length invariance, ScriptClip() appears the most suitable solution for adding runtime audio processing support.
Thanks!
