Convert HD 60i to HD 50i

Ozzie wrote on 1/1/2011, 4:11 AM
Can anyone tell me if it's feasible and how, using Vegas, to convert HD shot at 60i frame rate to HD at 50i frame rate for burning to DVD for playback on Australian PAL TV?

A family member in the USA has bought a Canon Vixia HFM31 camera (AVCHD) which according to the user manual I've downloaded has recording frame rate options of 60i, PF24 (is this 24p?) and PF30.

He wants to be able to playback videos from this camera on his American NTSC TV, but also give them to me for editing and then playback on our PAL TV.

Is it possible to do this conversion without serious loss of quality? Does conversion of frame rates create problems with the audio?

Appreciate any advice/suggestions.

Comments

farss wrote on 1/1/2011, 4:24 AM
It's pretty easy as the frame sizes for 50i and 60i are the same in HD.
Depending our what you want just render to the apprpriate 50i template. Make certain you have De-Interlace Method set to Interpolate in your project properties and if changing frame size e.g. rendering to SD make, certain you do It at Best.

You'll have no audio issues, it's all 48KHz.

All of that said most TVs in PAL land will play 60i, might pay to just see if the original plays OK.

Bob.
Mauriceh9 wrote on 1/1/2011, 5:20 AM
Hi Farss,

I have been grappling with a not unrelated issue. I want to buy a camera that will film movies so that I can capture something that might occur serendipitously when I'm out and about without my luggable camcorder. But, at the modest price point I'm at all the cameras sold in the UK capture film at 30fps. So following the logic applied to your answer I could use my Vegas to convert that to 25fps.

I did a test converting converting a clip of HDV 25fps to HDV 30fps and it worked fine. So I put both the 25fps and 30fps clips on the timeline and rendered that to a WMV at 25fps and that worked fine too. Well done Vegas.

Cheers, Maurice
farss wrote on 1/1/2011, 5:42 AM
COnverting 25p <> 30p is a different problem than converting 50i <> 60i. You have half the temporal resolution to play with and things can get nasty.

The other issue to be aware off is the standard frame rates in Region50 (PAL) and Region60 (NTSC) are what they are for a very good reason, flicker from lighting sources. Twice years ago I took my PAL camera to NTSC countries and both times I hit this problem. If you only want to shoot outdoors then you will not have this issue.

Bob.
Ozzie wrote on 1/1/2011, 7:57 PM
farss: Thanks for your fast response to my initial post.

I don't really understand the difference between the 50i/60i issue and the 25fps/30fps issue raised later by Mauriceh9.

Does 50i/60i relate to getting "clean" video playback on a TV in Region 50 versus Region 60 (presumably something to do with the respective Regions 50Hz vs 60Hz electricity supply systems)?

And the 25fps/30fps is the number of separate frames/pictures that occur in 1 second of video in the different formats?

Following on your suggestion for converting HD 60i to HD 50i of: "Depending on what you want just render to the apprpriate 50i template", I've checked out the available templates in "File" > "Properties" in Vegas 10.

The only relevant choices appear to be HD-1080 60i (1920x1080 at 29.97 fps) or HD-1080 50i (1920x1080 at 25 fps).

Doesn't this mean that in using the available Vegas HD 50i template to convert from the camera's HD 60i video, I'll also be forced to convert from 29.97 to 25 fps.

If so, won't I run into the "temporal resolution" issue (I don't know what that is exactly, but it sounds like loss of quality and ugly to deal with) that you mentioned in your reply to Mauriceh9.

Also, won't a change from 29.97 to 25 fps create an audio speed problem e.g. slowed speech or audio/video synch issues?