aevalsrc


Generate an audio signal specified by an expression.

This source accepts in input one or more expressions (one for each channel), which are evaluated and used to generate a corresponding audio signal.

This source accepts the following options:

'exprs'

Set the '|'-separated expressions list for each separate channel. In case the 'channel_layout' option is not specified, the selected channel layout depends on the number of provided expressions. Otherwise the last specified expression is applied to the remaining output channels.

'channel_layout, c'

Set the channel layout. The number of channels in the specified layout must be equal to the number of specified expressions.

'duration, d'

Set the minimum duration of the sourced audio. See for the accepted syntax. Note that the resulting duration may be greater than the specified duration, as the generated audio is always cut at the end of a complete frame.

If not specified, or the expressed duration is negative, the audio is supposed to be generated forever.

'nb_samples, n'

Set the number of samples per channel per each output frame, default to 1024.

'sample_rate, s'

Specify the sample rate, default to 44100.

Each expression in exprs can contain the following constants:

'n'

number of the evaluated sample, starting from 0

't'

time of the evaluated sample expressed in seconds, starting from 0

's'

sample rate