Variable playback speed of audio files

vvvv beta general
1

I would like to adjust the speed of an audio file during playpack.

I tried this by simply changing the value of the speed pin on the FileStream-node.
But when the value changes you hear a short break/click in the audio playback.

Is this because of my cheap audio card or is it like it is ?

Any other idea around to do this in VVVV ?

Markus

2

mm…jap. that is directshow again.

changing the speed of a graph actually pauses it, changes speed and restarts. therefore i see no way to do this without clicks in vvvv.

but. we’ve been talking a lot recently about linking vvvvs clock and directshows clock…somehow. or even being able to generate directshows clock manually in vvvv via an lfo…or such stupid things. this could then maybe allow you to change the rate of the clock (instead of the speed parameter) and consequently the playbackspeed of an audio/video file.

hower those fiction thoughts may not help you for now. what about pd? should be easy there.

3

Hi Joreg,

hmm PD … but PD can not do all the other things I would need for this project … and the user interface really is very basic (to say it friendly)

when googling for pitch, speed, audio, adjust, directshow usw., I found the following page:

http://www.chronotron.com/content.php?page=products#chronotron

Do you know this program/pluging ?
It allows realtime manipultaion of playback speed and it seems to work pretty good with WMP10 for audio AND video.

I am not a programmer at all, but maybe it is interesting for you !?

Markus

4

Do you mean PD cant do all the audio processing you need?

otherwise you can exchange data between vvvv and pd via netsend/receive or via osc.

this way this programs can work together and each can do what it can do best. pd for audio processing and vvvv vor visuals.

5

hm.

just downloaded the chronotron but didn’t find its directshowfilter (if there is any). if there was one i could probably include it into vvvv if they publish the parameters properly!

i’d also say. use pd only for the audio-processing part. and communicate with vvvv for the visual stuff. i’ll be back in office around 14th. maybe i could give you a hint on the pd-part (you have to pick up your mirror anyway).

seeyou.

6

@joreg: once i had quite different playback behaviour, depending on whether i changed the playback rate at the source or the sink of the ds graph. why the graph needs to be restarted?

7

hmm…its a directshow-thing. setting the rate of the graph actually stops and restarts it. therefore changing the rate will not do without hickups.

concerning different behaviour changing rate at source or sink: directshow-manual says you should not change the rate of individual filters but rather of the graph (who will then change rate on all its filters in the correct order) only. so i guess what you encountered was random.