How can I accomplish smooth video playback with QLab 2?

Question

My setup is the following:

• BlackMagic Television Studio
• MacBook Pro for controlling the BlackMagic TVS
• A video camera connected via SDI (stands in front of a blue screen)
• MacBook Pro with QLab 2.0 for back- / foreground connected to the TVS

QLab's rendering:

• 1x Video background @ 720p (QuickTime - JPEG codec)
• 3x Video footage @ 720p with alpha (QuickTime - HAP codec)

These four video layers needs to play at one time all together. But unfortunately the images stutters already when playing the video background alone. Image what happens when playing these four layers together. ;)

The MacBook is pretty new and filled with 16 GB of RAM, so I can't imagine thats is the biggest bottleneck. Is there a possibility to load the video's in the RAM before playing it? Or are there other things I can do to make the playback smooth? Maybe other cue-able programs?

Thanks in advantage!

PS - No audio is needed.

Answer 1

Sounds like a job for either re-compression, solid state drives or both. It appears that the BlackMagic Television Studio does has the media server that the other Black Magic ATEMs have, so you might also be able to load them in to that depending on their length.

Your bottle neck is almost certainly data rates, and the main options are to increase the rate your system can move data at (solid state drives), reduce the amount of data that needs to be moved (re-compression) or place the data somewhere that it can be accessed more easily (in the media server of the ATEM).