I have a Canon HFS100, which records in AVCHD at a bitrate of 24Mbps.

I have been transcoding in FCP 7 to ProRes Proxy, which uses a minimum of 36Mbps.

Below my post is Apple's Pro Res White Paper, which gives insight into the LT and Proxy flavors of ProRes. It seems to recommend that you should use LT for transcoding AVCHD.

My question is this: If Pro Res Proxy uses a higher bitrate (36) than the native bitrate of the Canon HFS100 (24), is there any practical benefit of using LT or even regular Pro Res as opposed to just using Proxy as your master file? Or are you simply creating larger quicktime files?

The whitepaper points out that Proxy should really only be used in off-line situations, but it seems that if Proxy is a higher bitrate than the native footage the camera shoots with, you've gotten as good as you're going to get so why not just stick with them as your master quicktimes ala the quicktimes created when using an EX1?

Perhaps there are other factors involved and I would love to hear from someone with greater knowledge.

Thanks,

Chad


White Paper

Apple ProRes 422 (LT): Like Apple ProRes 422 (HQ) and Apple ProRes 422, the new Apple ProRes 422 (LT) codec supports full-width 10-bit video sequences, but at a target data rate even lower than these siblings. Apple ProRes 422 (LT) weighs in at 100 Mbps or less, depending on the particular video format. It balances incredible image quality with small file sizes, and is perfect for digital broadcast environments where storage capacity and bandwidth are often at a premium.

Apple ProRes 422 (LT) is ideal for live multi-camera and on-location productions where large amounts of footage are acquired to disk. The low data rate of Apple ProRes 422 (LT) also makes it an excellent choice for transcoding complex camera codecs like AVCHD.

• Apple ProRes 422 (Proxy): The third new member of the Apple ProRes family is Apple ProRes 422 (Proxy). This codec maintains HD data rates below 36 Mbps, yet like its higher-rate Apple ProRes 422 siblings, it supports full-frame, 10-bit, 4:2:2 video.
Apple ProRes 422 (Proxy) is intended for draft-mode or preview uses where low data rates are required, yet full-resolution video is desired. It is the ideal format for use in offline editing workflows with Final Cut Server. The traditional offline-to-online workflow with Final Cut Pro has relied on the Offline RT codec, but today’s HD workflows demand offline video formats that support native frame size and aspect ratio. Apple ProRes 422 (Proxy) supports full 1920 x 1080 and 1280 x 720 resolutions, enabling full HD resolution while editing, and accurate representation of FCP motion effects from the creative stages through finishing.

Hi Chad,
your logic does seem to hold up, although there may be more alchemy under the hood than I know about. Best thing is try both and write back.

I also have an HFS100 on a Mac. I tried simply downloading the files via Image Capture or Adobe Bridge, but could only get the JPGs, not the video files. What's your workflow for getting the files into Compressor?

Also, I'm looking at removing the SD door. Ever heard of anyone doing that?


thanks,

Hi Scott-

I couldn't tell the difference to my eye between Pro Res Proxy, LT, Regular, HQ when transcoding the Canon HFS100 footage.

I used FCP 7 directly so I didn't have to go to compressor at all.

I guess the question is whether a higher quality of pro res would hold up better if you added filters, did color correction or made copies? I can't seem to tell the difference and once I transcode I really don't want to have to go and re-transcode the edited footage. The filing naming system in the camera is not pro level and the naming basically happens when you import and transcode via FCP. If possible, it would be great to save the QT as masters and not have to make a dmg and store the original files. That's what I'm currently doing, it eats up in the drive space if you shoot a great deal.

Anyone else have any thoughts?

Sorry I didn't reply. I didn't think I had any hits on this post!


PS. Not sure why you'd want to remove the SD door? What benefit are you looking to gain by doing this?

Hi Chad....was there a big difference in the QT files sizes?
Thanks, Craig