Change videostream during playback


We plan a interactive video projekt and need to change the videostream (simply switch to another file) during the playback in accoring to a viewers actions.

Is that possible with vvvv?


(If it ist not directly possible, maybe there is a workaround like playback several files and just switch between them or playback as textures with direct3d an switch between them.)

most simple solution is to switch the filenames of the filestream node. if you like to have blendings between two video sources you will nee two filestream nodes… there are several tricks to pseudo blend with just one filestream, but they are more complicated to achieve… how should your video switch look like?

it should switch directly (like a hard cut) without any latency

i heard that changing the filestream makes some delay/switching problems

With a raptor hard drive and 1 stream of video, switching filenames, latency is minimal, with yuv if it works on your system, the latency is very good. Picvideo mjpeg works well for this.

The old school trick of avoiding latency when switching files (rebuilding render graphs) would be to concatenate all your clips into just one file and then doSeek to a keyframe.
If you don’t have more than a handful of clips you can also just open all of them and play only one. (this will be limited by your computers resources, it might be interesting to find out where these limits are)

and yes, time to open a clip does depend on the codec you use.
Picvideo is quite a favorite here, XVid seemed quick to me, too - as long as you don’t scrub the video.

Then (if you’re desperate) there’s also the high-performance possibility of playing preloaded textures directly from RAM…


i made some tests

first i used a dv avi - there was a latency with or without playing it as a texture

than i user a mjpeg and it worked basicly - but the playback ist sometimes not fluently which cannot came from cpu or hd problems - this is a little bit curios

what i dont understand is: the dv and the mjpeg both dont work with keyframes so why the difference in the handling - maybe vvvv is better in supporting qt than avi

maybe i will test the doseek thing sometimes soon

thanks for your help


i have another problem now:

when i play back the sound in a different file the sound get out of sync with the video. thats why i included the sound in the qt-files but now the sound stutters during playback. why?

is there a solution to sync sound with video?
ist there a way to end the stuttering of the sound in the videofile?

thanks for your help