mixing 1080i on 720p timeline
 

Ok the scenario is this:

I am intending to purchase a JVC GZ-HD7 in the next few days primarily as a B roll cam for my wedding business, its also gonna double as a holiday cam, but thats just the excuse - I am one of those techno geeks likes the kit!

I shoot weddings with a JVC HD110 in 720p you see (Pal land) and really want to include B roll footage. My current B roll cam is a Panny G200 which is a great little cam for holidays but does not cut it for mixing with HD or even HD downconverted to SD so its really out of the picture. I obviously want true 16:9 as well and the HD7 looks like its gonna hit the mark in that respect.

So what am I rambling on about?

I am worried about Liquids ability to deinterlace having never tried to mix 1080i on a 720p timeline:

a) Can it perform OK?

b) How do I go about it?

I figured the following workflow:

Import to the 720p timeline, write to a file then use that native file in 720p. Sorry for the over simplicity if there is a better way, I have not gotten to grips with a mixed timeline to be honest!

Is it best to work with a 720p or 1080i timeline? Bearing in mind that I deliver currently on PAL SD DVD? 720p works fine on my PC too.

Sorry for the noob questions.

Ian

I'm not sure the JVC HD 7 uses standard HDV (its not HDV2 in this case) and I'm pretty sure that Liquid and most professional edit systems don't support it yet.. Different m2t file structure and GOP.

You would need to shoot with a Sony Z1U or one of the pro Canon HDV 1080i cameras which are compatible with Liquid. Then setup a 1080i timeline vs. 720p. 720p interlaces cleanly. My experience shows me to interlace progressive vs. deinterlace interlaced. But that's my experience and others may have a different take.

All JVC ProHD is good with Avid Liquid. If you use Xpress Pro or Media Composer, it will only work in 30P, and poorly I might add. Avid has lied to us for over 2 years about support. They hate the JVC camera, and do not ever plan to support it.

HD 7 isn't ProHD
 

The The JVC HD 7 that Ian is referring to isn't in the ProHD line.

http://www.jvc.com/product.jsp?model...hId=141&page=3

So, it is unknown whether Liquid supports this camera.

I thought he was talking about his HD110...ah

No worries. Read this thread http://www.avid.com/exchange/forums/thread/233548.aspx and then it gets better.

You don't need to use PowerDirector to take the TOD file off and convert it to MPG. You just copy it and change the name of the TOD file to M2T, import it, and snap it into a 1920x1080 29.97 sequence.

For the mix, I think start with 1920 format and then put a LinearTime Warp at 100% with Progressive mixing. Make that a container when it is finished (or drag the sequence) to your 720p Sequence. You would create a 720p sequence as your main edit and output (downresing the 1080 to it.) I have not worked out dropping 1440x1080 into a 720 sequence yet as I have tried it exactly once and got some clipped off parts. I suspect it is just an issue with dropped non-square in a square sequence. More research required.

Remember that Fuse is your friend when working through change resolutions step by step.

If you want an example of format changes, look at Douglas' Gaijan-eyes site for Encoding for the Web. http://www.gaijin-eyes.com/tutorials/enc/pagepre1.htm. Some great tips for moving from format to format.

Cheers guys. I have the cam now but due to a problem with Liquid, I havent started to use it yet. The problem I have is nothing to do with resizing and de-interlace, its more fundamental and deserves a thread all on its own :(


Ian

OK have fixed my probles and all is well :)

Workflow I have decided on actually does not use liquid till the import stage.

Originally it was going to be
- rename files from .tod to .m2t
- import into Liquid on 1080i timeline
- resize the clips to 67% (720 is 66.6666% of 1080)
- Fuse
- put fuse onto a 720p timeline
- Fuse
- copy to clips and use.

Probably in error there cos its from memory

This seemed a little long winded as the HD7 splits long files into 9 min segments (I think - 2Gb limiit issue - must be fat32 again )

I had a look at the free TMPG encoder, but that did not handle HDV at all, but the payware TMPGenc V4 Xpress works a treat as a single step process, (1080i in 720p out) well the trial version did so it looks like buying that!

Ian

Tsunami works for a lot of things well. Does dual pass encoding for both MPEG2 and WMV. It is easy to export a fused file and then encode it with Tsunami. But, it is not always best (MPEG2 SD from HDV2 worked better in Liquid, but I have V3.x of Xpress).

Hmm I have a strange problem now:(

I tried the method I outlined above and it worked - well it worked ok in so far as I had resized m2t files that played great in nero (resize was with tmpg 4 express) however, when I imported the files into Liquid, the picture was fine but the audio wasnt imported properly - Choppy no real sound at all. The m2t files imported from my HD110 - firestore work just fine in liquid.

The 1080i files import into liquid OK too, its just the externally converted files :(

Oh hum back to the liquid route. All very time consuming and its time I dont have. Always happens on a wedding that I need to edit within a week!

Ian