Forward two audio streams and control the order the buffers are forwarded.
The filter accepts the following options:
- expr, e
-
Set the expression deciding which stream should be forwarded next: if the result is negative, the first stream is forwarded; if the result is positive or zero, the second stream is forwarded. It can use the following variables:
- b1 b2
-
number of buffers forwarded so far on each stream
- s1 s2
-
number of samples forwarded so far on each stream
- t1 t2
-
current timestamp of each stream
The default value is
t1-t2, which means to always forward the stream that has a smaller timestamp.
Examples
Stress-test amerge by randomly sending buffers on the wrong
input, while avoiding too much of a desynchronization:
amovie=file.ogg [a] ; amovie=file.mp3 [b] ; [a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ; [a2] [b2] amerge