Please doublecheck my understanding about AVCHD and Macs

Question

Ours is substantially a Mac household because we appreciate the simplicity of OS-X and Macs in general. I am in the market for an AVCHD based HD camcorder and a new computer to handle its video. After a few weeks of reading here, I am leaning towards a PC, but before I do that, I would like to lay out my reasoning on the chance that I misunderstand some things that could tip the balance back towards a Mac.
First, with a powerful enough computer, under Windows, Sony Vegas (for well under one hundred dollars), will edit AVCHD directly. There may be other PC software that does this as well or better. Using such software, I can burn the AVCHD file to a standard DVD disk and play it on a blue ray player, or to an SDHC card and play it on a device that plays AVCHD from an SDHC card. I have been running the Windows 7 RC on our one last remaining PC, and it has been a pleasure to use. Maybe not all the way to OS-X, but close (in fact, compared to the one computer I upgraded to Snow Leopard and the problems I had with Front Row, in some respects the Win7 RC has been better than OS-X).
iMovie will import AVCHD, but in doing so it will convert it to AIC. That will cause the file size to grow by about 4X. And editing a 1080i video (or any interlaced video) will strip out half of the lines to down convert it to 540p. The alternatives are to either download and install some other software (free or low cost) to convert the AVCHD file from interlaced to progressive, or to limit my shooting to 24p....so I would be limited to only cameras that support that mode.
With all these changes to the file in iMovie, I would not be able to burn the file to a DVD or an SDHC card in AVCHD format to play on my blue-ray player or HDTV (both of which have AVCHD-capable SDHC slots for this purpose).
The other Mac software alternatives are either Final Cut Express, or Final Cut Pro. Final Cut Express has the same issues as iMovie. FCP will not down convert the file to 540p if I import to Apple ProRes. It has a list price of about one thousand dollars.
When I balance the issues, it is pretty clear to me that Win7 on a PC quad core desktop with a beefy video card is my best option for video. I still have my old Macs for doing day to day stuff. But I would love to find out that I have missed something and that I can edit and export AVCHD on a Mac without the hassle of bloated files and kludgy workarounds.
Thanks in advance for your consideration.

Answer 1

Barry Speronello wrote:
Thank-you both for your responses. Winston, please let me ask for clarification of some of your points. If I understand you correctly, maybe I can stay with a Mac and just buy a much bigger hard drive to handle the big AIC files.
It's possible to save a great deal of space by importing your AVCHD files as AIC for imovie and copying them (drag and drop to an area on your drive for archives), once you have edited your video in imovie, you can delete the project and associated AIC files content in the knowledge you can always import to AIC again from your archive should you ever need to return to re-edit.
You wrote: "...well it's not actually all that bad since your 1080i is actually only 540 fields every frame". I am impressed by what I see as a significant difference between 480p (p, not i) and 1080i images on a large TV. That is why I was focusing on 1080 HD camcorders. Is there something special about the 540 line export that would make it materially better than 480p for display on a modern 46" plasma HDTV?
I suppose you could say there was something special about 540 lines of resolution, in that twice 540 is 1080. 1080i actually displays 540 odd and then 540 even lines 30 times a second, throwing away the odd lines and making the even lines progressive isn't quite the same thing but it gives a surprisingly good result, much better than proportionally better than 480.
Take a look at this movie (ignore the camera work/standing to near the bass player - it's our party and I'd had more than a few beers),
http://gallery.me.com/gartside1104#101874
I used a Sony HDR SR8 AVCHD camera (1080i/25 fps @ 15 mbps) and a canon xm2 DV camera (576i/25fps) the later being quite a good camera. I made the mistake of shooting in 4:3 with the DV camera so had to crop the video to the equivalent of around 433 vertical lines which makes it a little worse than your 480i but you get the idea. Don't forget to view the video as large and set it to play at full screen.
The information that one can export nearly source-quality 1080i video after editing in iMovie as AIC is encouraging to me. There are 3 points to that for me.
You can't export 1080i from imovie, I didn't actually say that, what you can do is export 1080p, Although I think we are supposed to be able to export 1080i because there is a setting for it although it doesn't work. I'm assuming it's a bug that will get ironed out, the same 1080i export option in QT works just fine.
1) The point that you make earlier in your note that upon conversion to AIC only "...technically speaking only a small amount of loss in quality..". And the inference that there will be no further loss in quality upon the back-conversion from AIC to AVCHD. That is a pretty subjective analysis and I'd appreciate others' opinion on the degree of quality-loss upon that double conversion (AVCHD to AIC to AVCHD). I am skeptical, but open to the possibility.
You can't export to AVCHD with imovie, I didn't actually say that, what you can do is export to AVC. (AVCHD is h264 in an mpeg2 stream, AVC is h264 in an mpeg4 stream, they may contain the same codec but have different containers). And yes I agree, every conversion will result in some quality loss, noticeable or not. I don't use a pc for editing and have never used sony vegas, but I would imagine that native editing merely means the particular chunk of video you are applying an edit to is decompressed rendered and re-compressed and would result in a similar loss of quality.
2) I wasn't aware that Quicktime would export 1920x1080 AVCHD video from a file that had been converted to AIC from 1080i AVCHD. What version would I need, and is it still available. I have Snow Leopard that I will eventually be re-installing on my machines (once the issues with Front Row and some other things are corrected). Will QT-X in Snow Leopard do this? I do not own QT-Pro. Can I still purchase it if I need it to do the export?
Again Quicktime doesn't export to AVCHD, but it does have 1440 x 1080 and 1920 x 1080 AVC export settings. What I was trying to say was that while I don't have one, I was assuming that many blu-ray players and tv's with card slots would support the playback of AVC as well as AVCHD, although I can't in anyway be sure.
3) I presume that the re-exported files go back to being much smaller than the AIC version...ie, that they are about 1/4th the size of the AIC file from which they were created? Please confirm that. I need the compactness of AVCHD to fit a reasonable amount of video onto standard DVDs and reasonably sized SDHC cards.
The AVCHD files that I started the aforementioned movie with were 15 mbps, AIC decompresses these to between 80 and 100 mbps, the movie I created at 960 x 540 is about 3.6 mbps
Regarding burning of the exported AVCHD file to DVD or SDHC card, couldn't I use Toast, as suggested by Steve Mullin above, to do that?
Sorry I don't know anything about toast, I'm assuming you stick the AVC file on the DVD or data card as data and not as a DVD or other format.
Finally, I am not familiar with AVC and don't know if my devices will handle it (the user guides only mention AVCHD). If it is just a lower-res version of AVCHD, then I suspect that they might handle it, but I don't think that it would do what I want it to do. Is it lower res AVCHD, or is it a different way to output 1080 resolution video?
Hopefully I've answered that.
QT Pro is a key that unlocks a number of features in QT 7, QT 7 is still available and so is the pro key, although as I say it does not export to AVCHD. If the AVC format is a problem for you getting it to your tv, then the mac may be an issue for you as I'm not aware of any software that will create AVCHD on the mac.
Message was edited by: Winston Churchill