Clip duration is not correct.

[guido.nicolini]

Hi, I'm using Resolume 7.2.1 and I'm facing a strange behaviour of Arena.
I'm using it as a content player, that's all. I have only one Layer, and the composition is playing about 900 different contents, that are created in DXV with the sam length that is 20 sec.
For my usage it is essential that Resolume respect the exact duration of each content.
All the speed parameters (Composition speed & Clip speed) are set to 1.
The problem is that after 9 - 10 minutes the contents are loaded 1 sec before the correct timing, after 10 minutes the content are loaded 2 sec before the correct timing...
Basically, seems that Resolume running a little bit fast and became 1 sec faster every 10 minutes of playlist.

Any suggestion ?
Thanks.

[Zoltán]

Playing clips in auto pilot it might happen that the clip end is not in complete sync with the rendering.
Imagine playing 25 FPS clips in a composition running at 60 FPS. There is no guarantee, that the last frame of the clip will be displayed for 1/25th of a second, as that doesn't match with 60 FPS. Similarly specific length clips might not end exactly on render pass. Resolume is also not rendering a t a locked frame rate, so composition FPS can vary depending on the system loads.
In these cases the auto pilot might fire the next clip a bit earlier. Over a long time, this bit can add up to seconds, and look like what you are experiencing.

Another thing which could have an effect on playback speed is the Sound card's sample rate accuracy. Resolume gets the playback timing from the sound card, and if the sound card sample rate is not 100% accurate (which it is not ) you'll see drift in playback, compared to another system which is saying the same sample rate. This is why often a master clock is used to sync all devices across a production.

Does this explain things a bit?

[guido.nicolini]

Thanks Zoltàn for your prompt reply.
Here we have only 16 different contents, all rendered at 60 fps, all with the same length that is 20 sec, all without sound. Resolume is used to manage the playlist showed on a LED perimeter system in a stadium of soccer, and in this particular case the perfect timing is a must.
I understood all your explanation / reason, but after only 10 minutes that means 40 different contents loaded - executed - closed by Resolume, it's moved 1 sec faster that the real clock timing, and seems to be too much.
I have altro tried to increase the buffer size of the sound card section without any positive results.
I know that Resolume is oriented to another usage (VJ) but due to the fact the is really powerful and flexible my idea was to use it just a "advanced" Media player...

Do you have some other suggestion for me ?
Thanks in advance.

[Zoltán]

Using an external sound card synced to house Wordclock might help with the sound card drift.
I'd use an external timer bound to system time, to trigger the videos via OSC, if timing is so important.

[guido.nicolini]

Thanks Zoltàn,
I'll do some test using external OSC timing source then I'll back to you.