audio dropout on 3rd party tape at DVinfo.net

Mark Ahrens · June 30th, 2003, 09:32 AM

I am trying to transfer a friend's footage from tape to dvd using my XL1S. He has a 1 chip Mini DV camera (sony or something) and the audio (12 bit) completely drops out at irregular intervals . . . just brief 1 sec abrupt cut outs. I have replayed certain segments to verify that the audio is there and that the camera is just not playing the audio continuously (ie. the dropout placements are different each playback attempt). The meters reflect the problem . . . so it's not a connection issue. The "12-bit" text in the display/eyepiece flickers or coincides with the dropouts. It's as if the camera is second guessing the audio settings while playing back and momentarily readjusting . . . causing the dropouts.

Are there incompatibility issues with 1ccd to 3 ccd cameras?

Any ideas?

Jeff Donald · June 30th, 2003, 09:44 AM

The number of CCD's has no effect on audio transfer or reproduction. The cause may be related to 12bit recording and the use of LP speed rather than SP speed. Are you playing the tape back on the camera that originally recorded it? The dropouts are probably due to incomplete error correction on the camera playing back the tape.

Mark Ahrens · June 30th, 2003, 09:55 AM

No, the tape was recorded on my friends consumer camera. I have tried playback in LP and SP modes with the same result.

What is "incomplete error correction"?

Any work arounds? Or am i relegated to having to borrow the camera used to record it?

Thanks for your help!

Bud Kuenzli · June 30th, 2003, 02:59 PM

If I were in your shoes and could not get ahold of the original camera, I would record the tape twice and assuming I got different drop-out places I would simply cut and paste the "good" sound from one track into the empty spot on the second track. In Final Cut Pro this would be simple but of course I have no idea what you have available for post, but anything approaching pro software should allow you to cover a bad portion of one tape with the good portion from another capture, assuming, as you say, that the dropouts are random.

Jeff Donald · June 30th, 2003, 03:51 PM

Error correction is used in all digital formats. If there is a small dropout the error correction uses information before and after the dropout to try and correct the missing audio and /or video. If the dropout is large, the error correction can't do it's job completely and audio errors may be heard. The errors may be caused by problems with the tape (physical damage, stretching, etc.) or the playback or record unit.

Many times the errors can be caused by the recording unit being slightly misadjusted. If played back by the same recording unit the errors go away.

Tapes recorded in LP, rather than SP, are generally harder to playback and may contain more errors.

June 30th, 2003, 09:32 AM	#1
Mark Ahrens Major Player Join Date: Dec 2002 Location: Plantation, FL Posts: 239	audio dropout on 3rd party tape I am trying to transfer a friend's footage from tape to dvd using my XL1S. He has a 1 chip Mini DV camera (sony or something) and the audio (12 bit) completely drops out at irregular intervals . . . just brief 1 sec abrupt cut outs. I have replayed certain segments to verify that the audio is there and that the camera is just not playing the audio continuously (ie. the dropout placements are different each playback attempt). The meters reflect the problem . . . so it's not a connection issue. The "12-bit" text in the display/eyepiece flickers or coincides with the dropouts. It's as if the camera is second guessing the audio settings while playing back and momentarily readjusting . . . causing the dropouts. Are there incompatibility issues with 1ccd to 3 ccd cameras? Any ideas?

June 30th, 2003, 09:44 AM	#2
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	The number of CCD's has no effect on audio transfer or reproduction. The cause may be related to 12bit recording and the use of LP speed rather than SP speed. Are you playing the tape back on the camera that originally recorded it? The dropouts are probably due to incomplete error correction on the camera playing back the tape. __________________ Jeff Donald Carpe Diem Search DVinfo.net for quick answers \| Where to Buy? From the best in the business: DVinfo.net sponsors

June 30th, 2003, 02:59 PM	#4
Bud Kuenzli Regular Crew Join Date: Mar 2003 Location: North Pole, Alaska Posts: 197	one work around If I were in your shoes and could not get ahold of the original camera, I would record the tape twice and assuming I got different drop-out places I would simply cut and paste the "good" sound from one track into the empty spot on the second track. In Final Cut Pro this would be simple but of course I have no idea what you have available for post, but anything approaching pro software should allow you to cover a bad portion of one tape with the good portion from another capture, assuming, as you say, that the dropouts are random. __________________ on the Internet, when you get where you're going you still don't know where you are

June 30th, 2003, 03:51 PM	#5
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Error correction is used in all digital formats. If there is a small dropout the error correction uses information before and after the dropout to try and correct the missing audio and /or video. If the dropout is large, the error correction can't do it's job completely and audio errors may be heard. The errors may be caused by problems with the tape (physical damage, stretching, etc.) or the playback or record unit. Many times the errors can be caused by the recording unit being slightly misadjusted. If played back by the same recording unit the errors go away. Tapes recorded in LP, rather than SP, are generally harder to playback and may contain more errors. __________________ Jeff Donald Carpe Diem Search DVinfo.net for quick answers \| Where to Buy? From the best in the business: DVinfo.net sponsors

June 30th, 2003, 09:55 AM	#3
Mark Ahrens Major Player Join Date: Dec 2002 Location: Plantation, FL Posts: 239	No, the tape was recorded on my friends consumer camera. I have tried playback in LP and SP modes with the same result. What is "incomplete error correction"? Any work arounds? Or am i relegated to having to borrow the camera used to record it? Thanks for your help!