missing/corrupted AVCHD files? or am I missing something?
 

Hi there,
I've tested a Sony XR-520 during an interview (handheld; worked well), and now a Canon HF S10 (once on a tripod, with a bad experience with auto-focus, and today handheld with manual focus, and that part worked fine), and after each of these three shoots, one out of the approximately five interview 'takes' was labelled as corrupted (actually, marked with a question mark) by VideoPier HD, which I use to export for Avid.
When it happened the first time, I blamed myself: user error with the camera. But now that it's happened a second time, and a third time (and with a Canon as well as a Sony), it makes me think it might not be the camera.
I have two theories. One has to do with long 'takes'. I notice that twenty-odd short shots I got AFTER this afternoon's interview (street scenes) are all fine. The three 'problem' files were all interview clips, which could have been 15 minutes long. Do long files sometimes cause problems?
Here's another hypothesis: each time I exported these files I used software called VideoPier HD (which exports Avid-ready QT files). VideoPier simply wasn't able to export the three files that it showed (in its thumbnail icons) as question marks.
If the problem is with VideoPier, I'd like to see if I can export the files another way... and I'm sorry to say I don't know how.
I use a MacBook Pro.
I still have two of the suspect (?) files on the Canon drive, at least I presume these are the files: they're in the BDMV folder... and I see two .MTS files with the right number in the STREAM folder.
Would someone kindly tell me how I can convert one of these troublesome files to QuickTime, so I can see if the problem is with the file itself, or with my software?
Thanks very much,
Malcolm

I'll add a bit more information, which may or may not help... I was just checking for possibly corrupt files in the camera itself. Certainly nothing marked with a question mark. Every file I can see plays just fine.
But here's the odd thing: when VideoPier reads the camera's hard drive, it sees seven files from today's interview, and exports six of them to QT (it can't do anything with the file whose icon is a question-mark). When I check out today's interview clips 'in-camera', I see only five files.
Something's not adding up.
Malcolm

One of the really neat things about AVCHD is the utter simplicity of transfer of video files to the computer. For some reason MAC software still seems to lag behind and be overly complicated in this respect.

For me, with the HF100, I pull the SDHC card and plug it into a USB reader, plug that into a USB port and the computer "sees" it as a drive or external storage device. I find the .MTS files and drag 'n drop to whatever folder I need to put them into.

With HF S10 you can copy the .MTS files from the internal memory over to an SDHC card to do what I describe above and go from there. Or use a USB cable from the camera to the USB port on the computer and copy them over.

Your problem probably stems from your NLE needing the the .MTS files to be converted to something else, and I suspect the corruption is happening in Videopier HD and the conversion to Avid ready Quicktime.

This is a goshawful complicated way of having to do it. I found the following link which offers information on how to work with AVCHD and MAC and may offer a better solution.

Editing AVCHD on Mac OS X with iMovie or Final Cut

Hi Bruce... thank you for this. I don't have Final Cut (either flavour), so I guess I'll try iMovie. I appreciate the help.
Malcolm

IT isn't long files Malcom. In the last week I have shot two theatre shows with the SR11 and XR500. Both shows in two parts of over an hour each. I thus have about 8 hours of AVCHD with no problems. I transfer to the PC with the Sony Browser software that transfers and stitches the FAT 32 files( on the camera hard drives)into one big file on the PC. I think your experiencing the problem of both using a MAC and needing to go to AVid. I do not believe these are as up to date with AVCHD as the PC software at the moment.

Ron Evans

Actually it IS the long files - they must be stitched together, or the first file in the series will show "corrupted".

With AVCHD, the max file size is around 17 minutes/2G in size, and once you exceed that, the camera starts a new file. There is software that comes with the camera to stitch the two files together, or there's a little utility someone on these boards cooked up, not sure where it is, but a search should find it.

I'm not sure why they designed it this way, but that's the way it is... longer clips get split on the media/drive in camera, and must be stitched.

Well I guess I didn't explain things very well. I really meant takes. Yes I agree the problem is with stitching the FAT 32 files together but AVCHD doesn't have a file size limit. It just depends what file format its recorded in. The cameras record to FAT 32, presumably to have compatibility between MAC and PC and maybe efficiency for small memory sizes. But in an NTFS environment they can be enormous!!!! If one is on a PC with a Sony camera there seems to be no problem using the Sony Browser software to transfer and stitch. People who have tried to bypass the cameras included software and just copy files to the PC seem to have problems. I started with the SR7 and now still have a SR11 and XR500. Shoot family stuff( small clips) and theatre ( nearly always over an hour for each "take", several times the take has been close to 3 hours almost 24G). Since the SR7 I now have over 400G of AVCHD files with absolutely no problems from day one. Edit native AVCHD with Vegas Pro8 for family videos and convert AVCHD to Canopus HQ to edit multicam with Edius mixing both SR11, XR500 and two tracks of FX1 HDV.
The problem isn't the "take" time. The problem is with the transfer software supplied by the camera manufacture or users bypassing this software and just copying to the PC. The files in the camera clearly have data that indicates which files form a "take" and if this isn't taken into consideration an error will occur in reading the files.
Ron Evans

Aha... all very interesting. I'll check the dvd that came with the camera (as a Mac user, I tend to ignore these) and see if it helps.
Cheers, Malcolm

So what do I do... the 'Digital Camera driver Disk' only works on Windows machines...
Two of the interview clips I got this morning won't load.
Any suggestions,
Malcolm

I don't know exactly where the thread is since the forums were re-arranged, but I seem to recall that there was a "command line" type "fix" for Mac (sorry, I'm on PC...).

Other option is to find a PC, load the software, download and transfer via a USB drive... once the files are stitched, they should work fine.

thank you Dave and Ron... will check into this. I've also contacted the makers of VideoPier HD (something I need as an Avid user; not sure if it's anything the rest of you would ever need). Will post back.
cheers,
Malcolm