We are experimenting with XAVC AMA in anticipation of our own FS7 finally turning up (any month now!).
We have now gotten hold of a decent quantity of FS7 25fps 4K footage, some in I-frame, some Long Gop.
Basically we are having great results with AMA performance to the I-frame material, but dreadful with Long Gop. The latter is incredibly sticky while scrubbing, drops frames constantly and generally makes it look like our computer is WAY underpowered.
Thing is, our computer isn't at all, and when we monitor subsystems nothing seems to be working especially hard... Quadro 4200, 32GB RAM etc, all quite moderately strolling along. Yet the timeline performance is an absolute dog.
Its looking to us like this must be a software problem, presumably with the Sony AMA plugin. That seems plausible maybe, given that people have been cutting F5 & F55 I-frame footage for a while now, but the Long GOP is brand new?
We'd REALLY appreciate any feedback from others to determine if this issue is universal or something bizarre in just our system.
I'd like to add that, with the FS7 4K I-frame material, we can more than comfortably run multiple layers with four or more real-time effects and a realtime LUT applied, and it absolutely sings along, even in non-proxy mode. Scrubbing is fast, playback is quick and perfect, all is well.
With L-GOP, even a single layer with no effects, no LUT, and proxy on 1/16th cannot play back cleanly. It will drop frames constantly, frequently "gum up", and generally be such a pig that it is completely unusable for real editing.
It also seems that the mere presence of L-GOP material through the timeline, even after if it is removed, causes similar performance problems to continue, even for I-frame material that is fine if cut in a project by itself.
All of this definitely has the character of a software bug to our eyes.
Here are our system specs:-
Avid version: MC 8.3.1
Sony XAVC AMA plugin: PDZK-MA2
OS: Windows 7
Processor: Intel i7 3930k
Motherboard: asus p9x79 pro
GPU: Nvidia quadro k4200
RAM: 32gb ddr corsair ram (4x8gb DIMMs)
System drive; 128gb Samsung 840 sata3 ssd
Media storage: RAID 0 array of 4*2tb western digital black 7200rpm hdds
Video monioring: Matrox MX02 mini to 1080p screen via HDMI