Losing 24 minutes of audio from 53 minute video

William Koehler wrote on 4/26/2009, 8:14 PM
One of my functions at church has been to videotape the Senior Minister at our Men's Thursday Morning Bible Study. This lasts almost an hour. I setup my Sony HDR-HC9 with a Rode Stereo Video Mic., set the camera from audio AGC to manual gain, and the manual gain level. The camera also gets plugged into a small external monitor. I plug my headphones either directly into the camera or into the monitor, so if there is a sound problem, I know about it. I also have the camera plugged directly into a PC laptop via FireWire for direct capture using Vegas MovieStudio 9.

This past Thursday I recorded the 54 minute event, and generated a file checksum for the video file (1080i60 m2t), which allows me to verify file integrity as it gets copied around. I then copy the two files to a USB hard drive (WD Passport 160 GB). When I get home the two files get transferred from the USB hard drive to my desktop computer for verification, edit, render, and DVD creation.

My problem is this. When I load the video file into Vegas Movie Studio 9 on my desktop, Vegas does a scan of the file to build the sound waveform view, or I assume that's what it's doing. It skips over the sound from the ~2:34:07 (minutes:sec:frame) to ~26:33:14. Indeed, I can watch the scan skip from 3% to 50% in the blink of an eye. When I look at the sound track in Vegas, the sound flatlines between the aforementioned times and when I play it to start figuring out where my chapter marks should go from the sound, the sound goes dead quiet for that ~24 minutes.

I can play the file just fine in VLC and the sound is all there!
Does anybody have any idea what's up with this?
I've done this half a dozen times so it's 100% repeatable - on my machine at least.

Thanks in advance.

Comments

musicvid10 wrote on 4/26/2009, 8:25 PM
"I then copy the two files to a USB hard drive (WD Passport 160 GB)."

Try saving your files directly to your C: drive and see if that makes a difference.

I completely gave up on trying to use a WD Passport USB drive for any capturing, editing, or rendering. Too many problems.
William Koehler wrote on 4/26/2009, 8:35 PM
Thanks for the fast responce.

When I am capturing, I am capturing to the laptop's hard drive.
That's where the capturing is done and where the checksum creation is done.

The USB hard drive isn't used until after the event is over and done.
By the time it is pulled out, everything else except the laptop has been packed away. It is used ONLY as a transport mechanism to get the files from the laptop to the desktop. And the file checksums checkout, so I am pretty sure the file isn't getting corrupted along the way. I've been using this with excellent results for a couple of years.
Chienworks wrote on 4/27/2009, 3:41 AM
Try loading the files onto the Vegas timeline on the laptop (yes, i know that means unpacking it, sorry). Is the problem evident there? If so then something is wrong with the capturing process. If it's fine on the laptop then something is wrong with the file transfer process, in which case you might want to try transferring directly from the laptop to the desktop PC.
William Koehler wrote on 4/27/2009, 5:06 AM
My kit isn't so extensive that unpacking is a problem.
Thanks for the suggestion.

I have the blessing of knowing all my systems are consistent.
The laptop gets the same result as my desktop.
From ~2:34:07 (minutes:sec:frame) to ~26:33:14 the sound flatlines.

But it plays just fine in VLC 0.9.9 (the most current).

So at least I know my file copying procedures work.
When I did the original live realtime capture, Vegas told me 0 frames were lost. Something went bad somewhere!
richard-amirault wrote on 4/27/2009, 7:14 AM
You didn't actually say, but I assume that you didn't also capture to Mini-Dv tape at the same time. If you had then you could try uploading *that* version to your computer and see if it has the same problem.
William Koehler wrote on 4/27/2009, 1:23 PM
You are correct - I typically do not have a tape in the camcorder.
My observation is that I get cleaner audio if there is nothing in the tape transport.

I did get an answer on another Forum to use this program:

http://www.videohelp.com/tools/MPEG2Repair

I did and all is now Golden.

Thanks everyone.
Terry Esslinger wrote on 4/27/2009, 3:45 PM
I did and all is now Golden.

Except you don't know what happened and how to prevent it from happening again!
BTW I got warnings about possible adware and viruses from that site.