Unpredictable Movie Playback Speed

I am using a Catalyst v3 system on a G4 with two outputs and one internal hard drive containing all operating system and library files.

I am trying to synchronize a movie clip to audio on a CD in the Whole Hog 3 (controlling the server). The playback cues fire off of CD time code.

My problem is that the speed of video playback is highly unpredictable. From night to night, I may get up to a 2x (estimated) difference in video playback speed of the same clip with the same settings.

I have tried this using playback speeds of 'Recorded Speed' (DMX channel 8 @ 0) and other fixed rates.

Can someone lend me some insight into how the Catalyst times itself internally, and what the fix for this problem may be?

Thanks in advance for your help.

Sincerely,

Phil Gilbert

philjr@gilbert.com

Austin, TX

Quote:

---

Originally Posted by z6p6tist6

I am using a Catalyst v3 system on a G4 with two outputs and one internal hard drive containing all operating system and library files.


Austin, TX

---

G4? Which one? What speed - how many processors?
With which graphics card?
And what size hard disc?
And which Operating system?

You need to goto the About menu - as shown below in catalyst.
And send me the information code below the 'Catalyst OSXv3..'
Beginning here with 1033E1-1471...

And movie questions....

What codec did you use to render the movies you want to playback?

....who created your movie files?

How many movies are you trying to play at the same time?

You have dual outputs?

2 outputs on a G4 is a little bit optimistic. You should a at least get a G5, preferably with serious disks to do this.

I am still getting up to speed on conversion techniques and best formats, however the computer is a loaner and the show goes up tomorrow, so it may be a moot point anyhow.

I will pass on the version info as you requested Richard (later tonight), but I guess what my question really boils down to is this:

How does Catalyst play back movies at 'recorded speed'? Is this speed based off of the processor, the computer clock, voodoo witch science?

I completely understand the qualms about the processor speed and dual outputs. Although I am aware that the processing of a black second display will have some effect on the computer's speed, I have not had any problems, and I am quite happy with the results.

During the cues in question, I am only running one layer of video. I have tried using the play speed to lock in the speed at which the video plays back in relation to the audio. When that didn't appear to be consistent, I checked the new manual and found the function pertaining to setting DMX address 8 (of the given layer) to 0. My interpretation of the manual was that this would play back the video at exactly 1x speed. I would tend to think that if there were processor issues (not enough power) I would see choppiness (as I have with layering intense effects on top of moving images.

So, although I am aware that I may be pushing my hardware a little bit, can anyone give me any tips as to why this is happening?

Does the channel 8 setting 0 really play back at 1x speed?

Thanks for your help,

Phil

Quote:

---

Originally Posted by Martin

2 outputs on a G4 is a little bit optimistic. You should a at least get a G5, preferably with serious disks to do this.

---

it just about works if you only have a couple of things playing back - on two outputs - we did this on Jerry Springer the Musical - but maintaining playback accuracy is just not possible on internal ATA drives - esp when you have the OS on the same disc.
They just go off and do other things.

Quote:

---

Originally Posted by z6p6tist6

During the cues in question, I am only running one layer of video. I have tried using the play speed to lock in the speed at which the video plays back in relation to the audio. When that didn't appear to be consistent, I checked the new manual and found the function pertaining to setting DMX address 8 (of the given layer) to 0. My interpretation of the manual was that this would play back the video at exactly 1x speed. I would tend to think that if there were processor issues (not enough power) I would see choppiness (as I have with layering intense effects on top of moving images.

Phil

---

The software does actually play back at 30fps if it can. and it sticks to 30fps. it can be accurate.

If you need the computer to 'sync' accurately to a music source - you have to use timecode of one form or another.

This is because computers exist in their own worlds, they use crystal clocks which are not accurate between computers- which change their frequency with temperature, 2 computers trying to playback audio can and do drift within seconds because their cpu clocks are running at slightly different frequencies.

I did a test with 2 different g4's about a year ago. I started an audio track playing back on both computers - and within about 30 seconds there was an audible different between them.
This was with pro-audio software.

---
to try and help this - d56 can take a timecode input.

---
The main problem you are facing - is your drives-
The problem with internal drives is that they just seem to go off and do other stuff.

I will wait until we know what computer and os you are using before making any further suggestions.
You are probably using photojpeg files as well. they dont playback very consistently.

testing on a dual 2Ghz g5 with a single scsi drive - its possible to playback 3 dv-pal/dv-ntsc movies and have long-term (minutes )30fps accuracy- the 4th layer works very close to 30fps- but reduces long term accuracy.

Thank you.

I think that pretty much answers my question.

I completely forgot to write down that information last night. I will try to put it up tonight.

In reference to problems running everything off the same drive...Is it worth attempting running my content off of an external FireWire hard drive? Is this anywhere near fast enough to consider? I'm not sure if the computer would have FW400 or 800.

And as a side note to that, is the Library location set during installation of the Catalyst software? I have not noticed a reference to this setting anywhere. Do you have to re-install the software to change your Library location?

I think that's it for now.

Thanks for all the help!

Phil

Quote:

---

Originally Posted by z6p6tist6

Thank you.

I think that pretty much answers my question.

I completely forgot to write down that information last night. I will try to put it up tonight.

In reference to problems running everything off the same drive...Is it worth attempting running my content off of an external FireWire hard drive? Is this anywhere near fast enough to consider? I'm not sure if the computer would have FW400 or 800.

And as a side note to that, is the Library location set during installation of the Catalyst software? I have not noticed a reference to this setting anywhere. Do you have to re-install the software to change your Library location?

I think that's it for now.

Thanks for all the help!

Phil

---

firewire 400/800 worth a try for a couple of layers. dont fill the drive.

no you set the location of the library files from the user interface.
download the new manual, it tells you what to do, and where to do it.

You can select up to 8 folders all of which can contain content.
The content can be on any drive and changed at any time

Quote:

---

Originally Posted by z6p6tist6

In reference to problems running everything off the same drive...Is it worth attempting running my content off of an external FireWire hard drive? Is this anywhere near fast enough to consider? I'm not sure if the computer would have FW400 or 800.
Phil

---

With firewire - the speed of the interface isnt important - whats important is that the drives that all these boxes use are just standard ide drives.
It the drives inside these things that arent too great - if you need 4 layers of playback,
If you just need 2 layers, then firewire is ok

Thanks Richard!

The show was a huge success, and I was very pleased with my first use of Catalyst.

I appreciate the comments from everyone and look forward to working with the technology quite a bit more in the near future.

I did not get a chance to try using a Firewire drive for my content, though I probably would in the future as there definitely were some issues I was having that were more than likely tied directly to the fact that I was streaming from the same drive as my operating system and application.

Check out a few pictures of the show:

Pic 1 (w/ Catlayst)
Pic 2
Pic 3
Pic 4
Pic 5
Pic 6
Pic 7 (w/ Catalyst)

Cheers,

PG

Quote:

---

Originally Posted by z6p6tist6

Thanks Richard!

The show was a huge success, and I was very pleased with my first use of Catalyst.

I appreciate the comments from everyone and look forward to working with the technology quite a bit more in the near future.

I did not get a chance to try using a Firewire drive for my content, though I probably would in the future as there definitely were some issues I was having that were more than likely tied directly to the fact that I was streaming from the same drive as my operating system and application.

PG

---

Phil.
Thanks for the pictures.
This wasnt your machine? You couldnt put another drive inside it? Rather than use firewire?

Did you create your own movies - or did you use all the stuff on the machine?

The box was a demo unit that we were trying out. I had never used Catalyst before, so it was basically a 'trial by fire'. I think if I were to use the same rig again I would definitely try a firewire drive for content storage. I actually had a couple on hand, but by the time the idea came around, the show was already upon us, and I didn't want to make any hardware changes.

The first output was sent to one of two projectors at a time. One of the projectors was a 3000 lumen unit used for projecting onto a flown in 12x16 screen. The second was a 6500 lumen unit used for projecting onto the cyc (as seen in two of the photos above).

The second output was sent to two identical 2000 lumen projectors used for aerial effects over the audience. (One of the projectors was switched to 'rear projection' so that they would mirror each other. Thanks to Brad Schiller for the recommendation.)

Most of the content I used was stock Catalyst content. I also pulled some clips off of some DVDs for use during the light show.

During two or three sequences of the show, I used the Catalyst for slideshow duty, which allowed me to do some very nice movement and transitions with still photos that would not have been possible using PowerPoint. I found the image speed feature to be a lifesaver...and I beat my head against many walls because of it. Just like the mspeed feature on Cyberlights, but I kept forgetting about it.

Hmmm. I think that sums it up.

Quote:

---

Originally Posted by z6p6tist6

The box was a demo unit that we were trying out. I had never used Catalyst before, so it was basically a 'trial by fire'. I think if I were to use the same rig again I would definitely try a firewire drive for content storage. I actually had a couple on hand, but by the time the idea came around, the show was already upon us, and I didn't want to make any hardware changes.

The first output was sent to one of two projectors at a time. One of the projectors was a 3000 lumen unit used for projecting onto a flown in 12x16 screen. The second was a 6500 lumen unit used for projecting onto the cyc (as seen in two of the photos above).

The second output was sent to two identical 2000 lumen projectors used for aerial effects over the audience. (One of the projectors was switched to 'rear projection' so that they would mirror each other. Thanks to Brad Schiller for the recommendation.)

Most of the content I used was stock Catalyst content. I also pulled some clips off of some DVDs for use during the light show.

During two or three sequences of the show, I used the Catalyst for slideshow duty, which allowed me to do some very nice movement and transitions with still photos that would not have been possible using PowerPoint. I found the image speed feature to be a lifesaver...and I beat my head against many walls because of it. Just like the mspeed feature on Cyberlights, but I kept forgetting about it.

Hmmm. I think that sums it up.

---

You will have to test a firewire drive on your machine to see how well it works.
Firewire is no faster than simply adding an additional ide internal drive.

Yes the 'Mspeed' or image speed parameter is vital for smooth image movement.
DMX isnt stable enough to do this by itself.
and DMX is never synchronised to the video refresh rate.
Moving lights get away with this because they have mechanical inertia that helps smooth the movement.

---

I hope you found it easy enough to understand.
I wanted to design something that people could do useful work in - in less than 30 minutes - from their first encounter.

I think its vital in the age of super - complex computers, that things get simpler to use, rather than more complex.