Mixing 720p and 1080i on same timeline

[Rich Perry]

I am trying to mix 2 formats together in the same timeline. 1080i shot with a Sony FX1 and 720p at 60fps shot on a JVC HD200. I am using prospect HD and loaded a Cineform preset into CS3 (1280x720 - 59.94p).

All is good with the 720p footage from the JVC however with the 1080i footage being at the wrong resolution naturally over scales in the timeline. This is probably a stupid question but is there anyway to bring the 1080i (intermediate) footage onto the timeline and have it downscale automatically to 1280x720 without the need for rendering? The 1080i footage is being interpreted at 29.97 and playback and rendered file seems OK although I am not sure if there is a quality loss on the 1080i footage rendering to 720p.

Hopefully someone has a good solution or workflow for multiple formats within CS3.
Thanks for any help!

[Graham Hickling]

Not quite what you asked, but Cineform's HDLink can do a nice convertion from 1080i to 720p either during capture from the FX1, or as a standaone conversion of your already-captured 1080i CFHD files.

[Rich Perry]

Hi Graham, HDlink is great at these conversions but
I was hoping to eliminate a step and rather then re-render
all my 1080i footage, just render it all out at the end.
I believe FCP offers this ability but was not sure if it's possible with
cineform and CS3.

any ideas how I can make both resolutions work on
a timeline without resizing one of them first?

[David Newman]

We allow 720p in 1080 timelines, but not the other way round (without rendering.)

[Rich Perry]

Thanks for the info David,

Is there a specific way of doing this? I opened a new cineform timeline 1080i (1440x1080) and imported a 720p (60fps) clip encoded already converted to cineform at 1280 x 720 and I still getting a red bar indicating rendering is required.

The strange this is when playing the clip without rendering, it plays back upscaled to fit with the rest of the 1080i footage, but after rendering it remains at the original smaller 1280 x 720 size,

[David Newman]

You need to set, Default scale to frame size, in the Premiere preferences, and that render to the wrong size goes away. The Red bar will remain, but playback will work in RT.

[Rich Perry]

Thanks David!

One last question for you if you don't mind. I am assuming that given this work flow, If I output both formats (720p and 1080i) from my (1080i) timeline to a 720p progressive file I am not loosing anything quality wise?

The source 720p clips are 59.94 fps so for best results should I be outputing a 720 x 1280 (1 for 1 pixel) 59.94 fps avi file?
Or mabey a 1080i file?

Thanks again for you help on this!

[David Newman]

You will lose quality when mixing, that can't be helped. If you want a 60p output, editing in 720p60 and transcode your 1080i source down. 1080i30 is only 30 fps.

[Rich Perry]

Thanks for the info David, it looks like a 720p timeline might be best option and down converting the 1080i in HDlink before importing.