Re: [PD] no more sound on iOS with biquad~ and libpd

On 2015-07-14 16:11, Jack wrote:

Hello,

Jumping fast to certain coefficient (for frequency around 40/50 Hz and Q around 0.7) cut sound on iOS (iPad) when i use libpd (it seems to be OK with MacOSX). I need to restart the iOS after. Do you know what I have to do to solve this issue ?

provide a test-patch.

two ideas:

• the quick jump causes some very high sample values. the iOS system

limiter~ mutes the signal and takes ages to recover (too long to wait). a quick fix would be to use [clip~] just before the [dac~]s

• the quick jump might cause a NaN to be introduced in the signal

vector; due to the recursive nature of [biquad~] all successive samples become NaNs. no quick fix for this. try to get the sample values after muting. e.g. using [print~], or even just [env~]...

fmasdr IOhannes