Video and audio live player

[Lib]

Hello everybody,

I have an upcoming project in which I'll need to trigger about 60 video clips, at any time during the performance. Each video clip is associated with a multichannel audio clip. I'm thinking of using Usine because of the video features and I've started some preliminary testing. I'd need the following features, all of them to be used live during the performance:

- change quickly and seamlessly video and audio clips,
- (gradually) change the speed of the clips,
- set loop start and end points,
- jump to any part of the video,
- keep audio and video in sync.

From what I understood the best way to deal with video in Usine is to convert the material to Motion Jpeg. My videos are 1920x1080 50fps.

I'm a bit confused on which video player module I should use: Video player has loop, start and end positions, speed and current frame number controls that seem to be what I'm looking for, while Player Image has less controls.

Moreover, what would be the best strategy to keep audio and video in sync, especially when interacting live with the video?

Thank you in advance for any hint!

Lib

[joffo78]

Hello. Video with sound in usine seems to be a tricky subject
Nevertheless you can have a look on this video to understand some interaction possibility :
https://www.youtube.com/watch?v=ZaovoouXfUw
Don't forget that the sound is much more demanding than the video
For this reason it is imperative that the sound must always be the master

[Lib]

Hi,
Thank you so much for the video, it seems to covers exactly what I'm looking for! Thanks as well for the tip of using the audio as the master, very good to know, and I wouldn't have necessarily thought so.
Kind regards

[Lib]

Hi, following the video you linked I managed to make a patch that works very well except one thing.

When I slow down the pitch of the audio sampler the video flickers between two frames. I temporarily solved this by setting the video playback speed slightly above 0, so that the video 'speed' is guided only by the audio. It seems to work, but I'm wondering if there would be a better way to do that, for example by converting the pitch values of the audio sampler into speed values for the video. I wouldn't like to skip frames or mess up things with my simple and crude solution.

Another problem is that I cannot find a way to define the parameters of the video output window. Am I right in assuming that the video output keeps the same resolution and fps as the file that is currently playing?

This looks very promising, it'd be great to use Usine for this project!
Thanks for your help

[joffo78]

your flicker problem is probably due to a decimal point problem.
Did you try to adjust the number of FPS with your sample rate (typically 24 fps for 48K) ?
If not, you can actually multiply the positon value by the number of frames and round it off before sending the value.
On the question of the dimensions and format of your video, you can try the resize module as well as change aspect ratio.
In short, I invite you to browse through the geometric part of the videos modules.

[Lib]

Hi, thanks for your help. I think the flicker occurs when the video sampler 'speed' parameter is faster than the frame rate sent by the audio sampler (the flicker is visible when the audio sampler pitch is very low). I tried your solution but it gives the same result. However, having a very slow speed in the video sampler seems to solve the issue.

This brings another question: is it possible to slow down the audio sampler pitch more than -48 semitones i.e. slowing its playback speed even more? I'd like to slow down the playback to 0 and I cannot find a way to do that.

[joffo78]

Of course.
Change the min and max value on the pitch fader ( right click on the object).
No limit with that !

[Lib]

Oh thanks! I somehow always assumed that a fader would automatically be set up according to hard-coded values (and kind of surprised by that choice in such an open environment as Usine is). I was obviously wrong, thank you!