Optimum conversion of 1920x1080i AVCHD to 1440x1080i

[Persistence]

I have a 2.5 hour long video project whose source video consists about 70% of 1440x1080i AVCHD, 20% of JPEG stills, and 10% of 1920x1080i AVCHD. It made sense to set up the project specs based on the majority content.

The 1920x1080i AVCHD would be hard to edit in a large project on a core 2 duo PC, and has to be downsized to conform to the rest of the project anyway, so I exported the clips to a 1440x1080i MPEG2 file at 25 mbps. I then imported that clip to the primary project, completed the editing, and then created a Blu-ray disc in AVC at 21 mbps. I used Pinnacle Studio 12.1 for each operation.

Problem: the sequences based on the native 1920x1080i video look rather blurry, worse than the native 1440x1080i, even in instances where I also transcoded the latter to HDV MPEG2.

Is there a generic problem with converting 1920x1080i to 1440x1080i?

Of all the intermediate codecs or conversion software available, which might be the most loss-less way to convert 1920x1080i AVCHD to a more editable format?

Thanks for any comments or experiences.

[minidv2dvd]

the 1920 to 1440 shouldn't be much of a problem. it's almost a direct conversion, 1440 is 1920 but with "squished" pixels, otherwise known as a widescreen flag. there are intermediate codecs like cineform neoscene or mxf you could use, but you shouldn't have to for that project. what i am surprised at is that pinnacle was able to do it at all. it has a really bad rep around here for good reason.

[Persistence]

Pinnacle performed the conversion, but with IQ loss. I don't know how much degradation is "normal," but would sure like to test some way to reduce it. If the reduction from 1920 to 1440 entails a tidy 0.75 ratio does that make it "slam dunk" and that any conversion program would yield more or less the same?

[minidv2dvd]

the problem you have was most likely created by the multiple format conversions. you took 1920 avchd mpeg-4 and converted it to 1440 mpeg-2 and then back to mpeg-4 when you exported it. maybe try the project over without converting it to mpeg-2.