View Full Version : AVCHD File corruption


Paul Haworth
February 24th, 2010, 10:57 PM
I was out on a 3 cam shoot using Panasonic HMC150s and ran into an issue. I have used the cameras in the past with success. I am using Vegas 9.0c on a Quad 2.8 machine with an internal striped array drive containing 4 7200 RPM drives. the system (as I said) has all worked in the past flawlessly and fast. this time when I opened the files (.mts moved to HD) I have some of the files that function properly, and some that don't. the ones that are not good seem to have a lot of artifacting and digital noise in them(big blocks of colors that pop up for a few frames, then kind of dissipate. It looks like a poor Codec, except that all of the files were recorded in the same exact format, and som of them work fine. I at this piont think that one of my hires possibly pulled the memory card to switch it without stopping the recording. If this is the case, is there anything I can do to repair the files?

I have tried transcoding them, but as soon as any peice of software that I have hits one of the bad spots in the file, it crashes out. the "clean" files transcode just fine. I am just absolutely stumped here as to what is happening and how to fix it, any help would be appreciated...

Ron Evans
February 25th, 2010, 08:56 AM
Not sure about the Panasonic but if you still have the cards and camera maybe the Panasonic is like the Sony's I have with a database repair utility in the camera. This may repair the files on the cards and you can try transferring again.

Ron Evans

Paul Haworth
February 25th, 2010, 11:59 AM
I rent the cameras, but the rental house is quite accomidating. they are going to let me come in and attempt a file repair. The only forseeable problem is that I have just the MTS files, so I have to run a muxer on them to re create the file structure. does anyone know of a muxer that will put the panasonic structure on?

Ron Evans
February 25th, 2010, 12:25 PM
I don't think that will work. It will have to be the original cards unaltered. The problem was on the card so once you took the files off, those files will corrupted and of no use. I believe the repair needs some hidden files that are on the card and needs the video files to be in the same location on the card etc. The data base file repair will only work on the original unaltered card as far as I know.

Ron Evans

Paul Haworth
February 25th, 2010, 06:02 PM
that sounds right. I am going to try a muxer, and see if it works, I only own one of the cards I used, and it still has some footage on it, other than this, I am out of options I think.

Paul Haworth
March 2nd, 2010, 12:13 AM
After a full day of testing, I can not seem to re-create the problem. I tried opning the card door, this just causes the Camera to pause recording. I tried each different format. I tried moving just the mts file into folders by themselves and running them. Everything I did looked like good quality HD to me. The only thing I can imagine at this point is the possibility of elecromagnetism scrambling the files before I could get them to the editor. does this sound like a viable reason to have dropped frames and artifacting at random intervals in an AVCHD file? has anyone seen this on files recorded to cards? at this point, I hust have to move along with what I have that looks good, but I still want to know what caused this, and how to avoid it in the future.

Ron Evans
March 2nd, 2010, 07:09 AM
IT is more likely a bad write operation to the PC. Something else like a virus program update etc running in the background took priority as the files were being copied. Do you have a virus program running on the PC?

Ron Evans

Paul Haworth
March 5th, 2010, 11:33 AM
ya, I think either way, i am up for some long painstaking edit time to cut around the bad frames, I think the laptop that we ended up using to transfer files was running the robocam. it is one of the network cameras that sends a feed down the net. that could be what got me. I was also hearing something about a sync problem. on the HMC 150s I was using the RGB HD out to go to a Newtek TCXD 300 switcher for streaming. the thought was that the cameras were out of sync with the switcher, and possibly some sort of feedback occured. I can't test this, as I dont own the newtek box, but since I am relatively young in the field, I haven't had to deal with a lot of sync issues that my forfathers did. the Tricaster recorded fine, the cameras did not, that's all I know.