Member
Brand new system from Highend. Mac Pro 2.66 with SCSI drive etc....
QuickTime clips about a minute or two long, 1024 x 576, Photo JPEG 75% or 50%, with 48 khz audio.
And in the middle of several clips, the frame rate stutters. And we are talking one clip playing on one layer...
Why?
Member
I´m in another city now, so I don´t have the system in front of me anymore. But it´s a brand new system running version 4 point something. Probably not the latest build, but that should not matter.
Developer
there is a lot of difference between photjpeg 75 and 50 and whenever you do anything that isnt standard def - the whole game changes. things are much more critical.Originally Posted by ping141
if you dont have any history with doing anything with digital video you will be in for a sharp learning experience- you will need to learn what works and what doesnt for whatever your system is.
most things do not work. you have to find something that works for what you need to do.
there are only a few things that do. its not the other way round.
what did you use photojpeg 75 or 50?
and are you trying to play audio at the same time?
Member
I have 10 years video expericene from high end post production to 360 x 288 VDMX vj´ing, so digital video and codecs are not new to me.
It seems that in the middle of certain clips that are a minute or two long, the frame rate will stutter a bit and then play smooth again. The clips that I have noticed this with were originally in 75% Photo JPEG with 48khz stereo audio. Then I lowered them to 50% in order see if it helped and it didn´t. It´s not a major thing, this show is up and running every night, and I´m probably the only person noticing this problem, but still. On a 2.66 Mac Pro with a SCSI drive and an x1900 card, anything should in reality play fine, at least one stream on these resolutions. They play flawlessly on my laptop in QTP from the internal drive btw. It might be something funny with my clips, but I can´t see what it could be.
And in order to track what plays well and what doen not it would be great to have a FPS history in the Catalyst where you could see and track when the frame rate dips. Also, the FPS indicator in the Layers window does not work when playing with audio.
Last edited by ping141; 28-01-2007 at 07:57 PM.
Developer
when you play with audio - playback is handled totally by quicktime.
so whatever happens with what you see if something quicktime is doing.
and audio takes priority.
quicktime player doesnt have to handle lots of layers and lots of fx...so it doesnt have so much to do. nor does it have to handle interfaces to lots of equipment like video input simulaneously.
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what size and frequency are all your display screens set to?
what is your screen setup?
do you see this when you dont have audio?
can you send me your pdf profile
Member
Using both outputs at 1024 x 768, 75 hz. I don´t use video input or anything else.
On one output the files are 1024 x 576, on the other 1024 x 768. This due to one screen being 16:9 and the beamer is squeezing the frame.
Problem files have been on both these outputs.
I´ll see if I can get the profile sent over.
Developer
so you are playing back 2 files at the same time?
Member
No. Only one file at a time. But I have several troublesome clips.
Expert
It could be that the jump happens when the drives have there caches flushed by the system. I know with the Xserve RAID there is an option to disable this so the cache is manged by the hardware controller and not the Operating system. The difference is quite amazing. I don't know if this is an option with your SCSI drive (I don't use one) but I have noticed this same effect when playing back longer files off Raptors.
Unfortunately I think Quicktime controls all this stuff so it is out of our mere mortals control.
This is just a guess so it could still be another issue. I am not that familiar with SCSI set ups.
Cheers
Toby
Member
That could be an explanation, actually. But QuickTime itself plays everything very nice, at least in the QTP, so it´s a little strange that it will make trouble here. But it seems to happen to my long clips.
This is a spanking new system from Highend and it came with an ATTO PCI card and a SCSI drive for contents.
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