AVCHD conversion to ProRes quality?

Is log and transfer from an AVCHD file to ProRes the optimum quality you will get out of the file? I saw an old post (not here) about working in ProRes, and then doing an online from AVCHD at a higher quality. Can I consider my transcoded ProRes as final quality, or should I be planning an online from original AVCHD files? I was thinking of these like HDV where transcoding to ProRes was pretty much the best they could ever be, am I wrong? Because an
online is going to be rough for this show, is it warranted?

The rest of this post explains some of the drawbacks to the project. And may be of less interest. The essential question at hand is stated above.

Another editor was originally hired on one of my current projects, a feature with lot and lots of dailies. (A low budget feature that I'm not sure why I took because the money is so low, god I'm doing it for the glory of it, please help me.)

Editor A (not me) started transcoding the files, I think he just popped everything into L&T, and went to bed, rise and repeat for a week. Editor B (me) receives files after editor A determined he didn't like editing/the movie/producers and stopped working on the show.

The files don't have the same name as the original, because each camera roll starts with clip 000.mts, so L&T I'm guessing kept a running count, and sometimes added spaces in the name? Because he, editor A, was always putting everything in the same directory/scratch folder.

My PowerPC G5, doesn't handle AVCHD in FCP, and never will. Voltaic handles it, it takes 8X running time...whatever. Some of the directories/files where overlooked I'm filling in. Voltaic doesn't really pass any meta-data. Quality from Voltaic seems on par with L&T.

The upshot an online is going to be rough, is it warranted?

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Is log and transfer from an AVCHD file to ProRes the optimum quality you will get out of the file?

Yes. You can empty a five-pound sack of manure into a twenty-pound sack, but you'll never end up with more than five pounds of manure.

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A low budget feature that I'm not sure why I took because the money is so low, god I'm doing it for the glory of it, please help me.

Working is better than not working.

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Because he, editor A, was always putting everything in the same directory/scratch folder.

Unless you're that guy. We're all better off if he's not working.

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The upshot an online is going to be rough, is it warranted?

Any technical argument in favor of it would be weak.

> The files don't have the same name as the original, because each camera roll starts with clip
> 000.mts, so L&T I'm guessing kept a running count

Unfortunately, AVCHD is even worse than Panasonic P2 media in that the file names are drop-dead simple (00000.MTS, 00001.MTS), but if you renamed the MTS files, you'll muck with Log and Transfer's ability to detect the files.

You're supposed to rename the files only in the Log and Transfer interface. I'm assuming that FCP will then write data into an XML file so that it can keep track of which 00000.MTS corresponds to which converted QuickTime movie. However, I have never used AVCHD except on tiny projects where I backed everything (original MTS files, folder structures as well as resulting QuickTimes) up the wazoo. So I don't know how Log and Transfer deals with a lost QuickTime, whether it's able to re-open the reel's folder structure and rename the files according to the changed user-defined file names.

But the process is a pain in the butt, so I think a complete backup would be easier to deal with than trying to redo the Log and Transfer. And yeah, I would try to convert everything at best possible quality. ProRes should do it.

Since you're dealing with a feature, with a presumed long edit process, why not do a test? Backup all your original AVCHD reels with folder structures intact to two other non-active external drives first. Then open up one reel, do the renaming in Log and Transfer, save, and then convert. Do a "dummy edit" of the resulting QuickTimes, with arbitrary In and Out points, speed changes, effects, Freeze Frames etc. Now dump the QuickTimes and redo the Log and Transfer. Do the file names get recreated properly? Do the edits reconnect to the new media properly? A test like this should only take 30 minutes to an hour. Personally I would be a lot more comfortable if I could see it work in front of me, hands-on.


www.derekmok.com

Thank you so much, it's such a pleasure to have an answer in my own language. AVCHD is the 5lb sack of shite. And ProRes is a 20Lb bag. :-) Got it.

>You're supposed to rename the files only in the Log and Transfer interface. I'm assuming that
>FCP will then write data into an XML file so that it can keep track of which 00000.MTS
>corresponds to which converted QuickTime movie

Clip IDs. That's how FCP usually keeps track of tapeless media. So when a media goes offline, you can right click and do a batch capture through L&T.


>My PowerPC G5, doesn't handle AVCHD in FCP, and never will.

Now, here's the deal. You try to avoid it. Or recapture the AvcHD as ProRes in an Intel machine. Question is do you need to recapture it? If the media is already online, and is captured as ProRes, and you want to shift it for organization, you can use Media Manager.



www.strypesinpost.com

You can transfer AVCHD to Prores with a third party tool……

Yea, Clipwrap does that, but I've heard it's slow.

[www.divergentmedia.com]



www.strypesinpost.com

> Clipwrap does that, but I've heard it's slow.

ClipWrap isn't *that* slow. Voltaic HD, now that is SLOOOOOW. I've used both, and switching to ClipWrap was like night and day. At only $10 more than Voltaic, ClipWrap wins hands-down in my books.


www.derekmok.com

I was under the impression that Apple didn't support Avchd on PPCs because it just didn't have the number crunching power to transcode avchd feasibly. Did you gt real time performance with it?



www.strypesinpost.com

> My PowerPC G5, doesn't handle AVCHD in FCP, and never will.

I never even tried. I always shot only very small projects on AVCHD back when I was still using a PowerPC G5. It took two days to convert one to two hours of AVCHD footage. And I always used either DVCPro HD or Apple Intermediate Codec (remember that little nugget?), since ProRes didn't work on PowerPCs, at least not as an editing/timeline codec or output format.


www.derekmok.com

>It took two days to convert one to two hours of AVCHD footage

Cripes. That sounds like doing a full debayer on RED footage, which is also much faster than that now.



www.strypesinpost.com

And don't you love it when you've got people asking the whole time whether the cut is done yet?

I always tell the story about the producer who was unhappy that I'd cut 28 minutes of an unscripted, untranscribed documentary -- with 40 hours of footage -- in one day. When I went in to tell him I was done for the day, he said, "You're leaving already?"

Head, meet clouds.


www.derekmok.com

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Ethan
AVCHD is the 5lb sack of shite. And ProRes is a 20Lb bag.

This thinking might induce people to choose too weak flavors of ProRes, such as LT, for transcoding their AVCHD. AVCHD's image sharpness can be quite high because it puts its bits to different uses than ProRes does.
ProRes's frame-by-frame compression is nicer than AVCHD's interframe, but it's the compression of the latter's I-frames that mostly determines image sharpness.
ProRes's 4:2:2 is nicer than AVCHD's 4:2:0 but image sharpness is mostly carried by the 4.
ProRes's 10-bit is nicer than AVCHD's 8-bit but this doesn't affect image sharpness.
Even when AVCHD shows nasty artefacts it can be sharp.

While many of ProRes's qualities are wasted on AVCHD material it's conservative to choose the ProRes flavor that wastes none of the quality AVCHD does have. I transcode AVCHD to ProRes [SQ]. I think I'd use ProRes HQ if my camera had a better lens.

Dennis Couzin
Berlin, Germany

[www.exitedit.com]



www.strypesinpost.com