Editing Monitor Advice

[Steve Burke]

Hi - hope I have got the right forum here.....

I run a PC editing system, with dual PC monitors. To view actual footage on a studio monitor, I pass this from my PC Firewire port, via my 'hoilday' camcorder ( not my XL2 ), and use the DV OUT function, to convert to the analog signals required for the monitor. This works great for colour correction / title placement etc. I have a few questions that you may be able to help me with....

1) The picture sometimes 'shakes' as though stopped 'between' frames. To overcome this I have to wind the footage on a few frames until the picture settles. The frames on my PC monitor timeline monitor are always steady and perfect. Anyone have any ideas on what I have not set correctly, or is this inherent in the DV OUT function not having a dedicated CODEC chip for the D-to-A conversion? I have tried it using the XL2, with similar effect, hence it's not my 'holiday' camcorder at fault.

2) I was thinking of investing in the Canopus ADVC110 for 2 reasons.
a) To use it as my monitor output to replace the 'holiday' camcorder
b) To use for A-to-D conversion when I convert Videos to DVD, instead of using the function on my XL2, which I use at present.
Can anyone help with the following Q's?
i) Will the Canopus unit help create a steadier picture while editing?
ii) The tech spec says it will only accept SECAM video input, although it does state it is NTSC and PAL compatible.... does that mean I cannot use it to capture PAL videos for conversion to DVD? It would seem an expensive bit of kit to just use it as a monitor output device.

All comments welcome. Many thanks. Steve

[James Henley]

Hi Steve,
I've had the ADVC110 for a while now and am very happy with it. To answer your questions....

i) I get the same 'shake' problem as you describe. I had assumed it was something which had to be put up with, but if anyone's got any good ideas about how to get rid of it I'd love to hear them!

ii) There are switches on the unit for choosing between SECAM and PAL and between NTSC and PAL. In other words yes you can use it to capture PAL for conversion to DVD. I've used it for exactly that many times with great results.

Hope that helps.

cheers - James

[Steve Burke]

Many thanks for your reply, and advice, James.

Can you please confirm that you get the shaky problem when routed via the Canopus unit, or are you going via a 'holiday' camcorder, like me?

[James Henley]

Sorry I wasn't very clear. I get the shaking with the Canopus device. I've just been playing round a bit and the shaking seems to be caused by field order problems. I tried changing the field processing options to 'deinterlace' and got a perfectly still picture on the TV. Obviously that means you you have to convert everything back if you want an interlaced final output though.....

cheers - James

[Steve Burke]

Thanks for your reply, James.
I'll give that a try, when I get a minute, in between editing.
I'll post my results here.
Many thanks.
Steve

[Steve Burke]

Forgot to ask what editing system you use, James. I use Premiere Pro 2.
Just had a quick look. What I have just realised is that in Project settings - playback settings, when I specify realtime playback, the only external device selectable is 'DV 25i (720x576)' - surely this should be 50i, and this may be causing the flicker? Any ideas how to add different external devices?

Can you confirm which interlace settings you change to get the steady picture, and under which option? Is it the 'playback' settings only you change, or the actual 'project' settings for the footage?

Many thanks.

Steve

[James Henley]

Hi Steve,

I'm using Premiere 1.5. The only options I've got available in the playback settings is 24fps, 25fps or 30fps. Not sure that having 50i as an option would make any difference anyway, as presumably what you output to the TV is the same as the capture format (which in PAL is 25i). I'm not very good on the technical stuff though so I might be wrong.

I got the steady picture by right-clicking on the individual clips on the timeline, then clicking 'field options' and selecting 'always deinterlace'.

I'd be interested if you find another workaround though :)

cheers - James

[Steve Burke]

Hi again, James.

Thanks for your reply.

Not in my studio today, but will give it a try later if I get bored.. :-)

Footage is shot in 50i. My understanding is that each 'frame' is made up of two 'fields' - the top and bottoms. The tv puts out the top first, then the bottom and hence creates the 'frame' with two fields. As PAL is 25fps, then this means there are 50 fields per second, hence the 50i. PAL camcorders record in the same format. The alternative is to shoot in 25p - 25 progressive, which shoots 'each frame' and doesnt bother about the upper and lower fields, as such. MAybe if we try some 25p footage maybe the flicker will go away? The reason I suspect the flicker could be to do with what I posted yesterday.... I only have ext monitor output option of 25i in the drop down menu..... hence 25i equates to 12.5fps, and I think this is why we are seeing 'in between' frames on the tv, hence the flicker..... I could be wrong here, so will stand corrected if you or anyone else can confirm.

It's just how to get the software to recognise to output the full 25fps to the tv instead of the psudeo 12.5fps..... it's that 25i option thats throwing me off the trail.....

Cheers for now.

Steve

[Steve Burke]

Can anyone assist me and James with this fairly 'simple' problem.

I'm sure we are not the only 2 editing on the forum. I assume it applies across all editing systems, not just PPro.

Your input is appreciated.

Thanks

Steve

[James Henley]

Hi Steve,
Sorry for the delay in getting back to you - had to actually do some work!

I think we're using slightly different terminology for the same thing. I had always been under the impression that the terms 25i and 50i were interchangeable and both meant 25fps interlaced. This is what the fourth post on this thread suggests http://www.dvinfo.net/conf/showthrea...&highlight=25i

Either way it doesn't really help with the problem! I'd be very surprised if PPro was outputting at 12.5fps - just doesn't make sense. I'm still inclined to think that's it's an interlacing issue and subsequently can only be removed by deinterlacing everything.

I see you've put a general appeal for help out though so hopefully someone elese can put us right!

keep smiling

cheers - James

[Steve Burke]

Hi again, James

50i and 25i been interchangeable makes a lot of sense - I was not aware these 2 terms were interchangeable, so thanks for clearing that one up.

This means when I see 25i as the only option in PPro, this means 25fps, which makes sense as the output.

I tried what you suggested, but on my current Master timeline ( 1h15min ) I have many razor'd clips, hence changing them all to deinterlace and then all back again is very time consuming, as they have to be done 1 at a time - if you mark them all, it wont do a global change?????

There has to be a PPro setting I'm missing here to get the stable pic......????

The deinterlacing steadies the picture, but why, as the monitor is interlaced???? Must do a conversion before output???? What happens if you export an .avi for Encore DVD with the deinterlacing in place on the timeline? Does the DVD start to flicker then?????

I'm sure we are not the only 2 on the forum who uses PPro..... even if someone can reply back to say the 'flickering' is normal, it would help.

Ah well, back to the editing work.......

Cheers

Steve

[Steve Burke]

Thanks also to Josh Bass, who helped with feedback via another thread.

For anyone else reading this thread, I have copied his comments here for completeness.

''Flicker issue: sounds like you're looking at interlaced footage. That's just how it looks when paused, if there's much movement in the paused frame; you're looking at two fields of video at once, two pieces of two different images-the odd lines from one image, the even from another.''