I posted a while back that I had encountered a similar problem, but don't remember if there were any replies addressing my problem, namely, when I run an analog regular 8mm tape shot on my Sony CCDV220 camcorder (machine records audio via PCM stereo)through my digi8 vidcam to capture via firewire, the result is always two channel containing the exact same audio track - that sounds mono (is that how VV draws mono tracks - left/right waveforms of the exact same audio?).

I assumed (and still do assume) that there is some difference in track arrangement that causes this. I get around it by capturing a copy of the PCM track via the composite outputs of my CCDV220 through my sound card, and then syncing that stereo track up to the captured video/mono audio. Once sync'd, I delete the mono track (or mute it) before rendering.

The 8mm cam in question was, in its day, top-of-the-consumer line, and, owing to the fact that it has jacks for two mono external mics (via RCA plug connections), is the cam I rely on to obtain a sound track free of mechanical noise produced by my other more up to date cams.

I'm not sure anyone here can help me with the mono problem that occurs when I play these 8mm tapes through my digi8, but, any suggestions/comments on the process I described above would be appreciated.

Thanks.

Caruso

The clip on the time line shows only one Audio track and the properties says it is mono. I am fairly new to VV and still running the demo would this cause it?
Can you shed more more light on the - "event "Channel" submenu to make sure you didn't accidentally set a stereo event to mono" - is this the camera or the software. the camera has no mono switch, only the 16bit, 12 bit I am set to 16bit.
If I capture a long piece the stereo items (as in post) remain as is but the otherbit suddley becomes mono after the auto split.
TIA.

Forgot to mention it is mono (one channel), but it is the plugged in device that the audio is captured and not the internal mic, so it is mono but only the left track is present.

TIA

Caruso:

Stereo events are drawn with 2 waveforms, Mono events just have one down the middle.

///d@

zcheema:

Right-click on the audio event, you'll see a "Channels" menu item, pick "Left Only" or "Right Only", depending on which stereo track has your only audio signal.

However, if you only have mono audio in the stream, the sub-menu will be grayed out.

I didn't think DV allowed mono audio, though.

///d@

SonicD:
I hear you and understand about stereo/2 waveforms and mono/1. That's why it took me a while to figure out my little problem. I use this older cam as a fixed video source during multi-cam shoots. The images aren't quite as good as my newer gear, but it is still a sound-capable piece, and, since it allows for external left/right channel mics, always gives me a clean audio track.

I was sickened one day to learn that the entire audio track from this cam seemed somehow to have recorded with a signal level so low that it was useless for my project. At first I didn't realize what the problem was, but, since all my other footage for the project had particularly noisy sound tracks (I hadn't concerned myself with cam noise and such on these cams, since I was counting on my fixed cam for the audio), I spent some time trying to tweak this weak audio and finally realized that, although VV detected a stereo source when I played this analog 8mm tape through my DV firewire, both waveforms were identical, producing, in effect, mono audio.

I'm no engineer, so I am not able to be as precise in my analysis as I'd like, but, I assume that there must be some slight difference in the way the original cam lays down/reads the track on tapes recorded in that cam which causes a problem when the newer DV cam tries to read/play back those tapes.

The video is fine.

If, instead of using the DV cam to digitize these analog tapes, I first dub them to DV tape via the composite connections (no Svideo on the older cam), I loose some video quality, but the audio is fine.

For me, the best solution is to record the audio only direct to my HD via my sound card, then let the DV cam digitize, bad audio and all, sync the audio only track to the newly digitized audio/video, then use that 'audio only' in place of the audio captured with the video in my final production.

I apologize if I've gone off topic.

If someone more technically astute than I would care to comment, I'd welcome your input.

As to Zcheema's problem, I'm wondering about his/her cam setup, and, whether mixing internal/external mic sources might be causing the problem. This is a total guess, but, it could be that, when you plug in an external mic (even into only one of the two channels), circuitry in the cam is designed so that it assumes you will be recording both channels via external and that the internal is designated as a narration mic which signal gets sent to a special audio track on the tape. Playing back on that cam might give you both audio signals which sound like stereo, but, when you play back on something else, only the external audio (or vice versa) is acutally coupled to the video.

The older cam about which I spoke above always records two separate audio tracks, one PCM stereo, one mono. If I activate the narration mic, that audio is captured on the mono track. When the narration mic is not in operation, a mono version of the scene being videoed is sent to that track.

You might check your cam's manual on this.

Hope this helped a little.

Good luck.

Caruso

Caruso:

Oh, hence my confusion. You *are* getting a stereo capture and file, it's just the "same" on both sides, which you are calling "mono".

And this is only happening when you play the tape from that camera on your DV camera? But when you capture through the analog-ins of the DV camera, you get your separate channels like you want? Do I have this right so far?

You said the older camera is an analog 8mm (perhaps "Hi8"?). Anh the newer camera that you're playing the tape on is Digital8.

I wonder if it's something like the old VHS decks that captured an analog linear stereo track, and a higher bandwidth (was it PCM? They called it "HiFi") stereo audio track using flying heads (it was "buried" under the video signal). These decks had a switch to select which track (or a mix) got used during playback.

Perhaps whatever format your older camera is using, it has two audio sources to choose from, and when you play it in the original camera, you're getting the better stereo source, and when you play the tape in the DV camera, it's picking off the lower-quality mono soundtrack, digitizing it to (identical) stereo, and sending it through Firewire.

I'd suggest reading the Hi8 manual to learn if this is the case, and then the Digital8 manual to see if there's a setting for which audio track(s) get digitized to Firewire.

///d@

I apologize if I'm misunderstanding, but here's how I get this thread so far...

zcheema is reporting that stereo audio (recorded in a sony 9000 )captured to VV using the Panasonic 1000 cam comes in mono. Capturing using the Sony is OK.

If so, I might check the Pana cam settings.

*******

caruso reports that regular-8mm (not hi8) tapes with pcm stereo do not recover the pcm tracks when played in a D8 cam, so caruso dubs to D8/DV via analog ports to recover the pcm before capture.

If so, I believe this is due to the rare use of pcm in standard-8 cams (perhaps ony two models were made?). Either the pcm tracks are not in the same place as Hi8 tracks, or perhaps the D8 cam detects the standard-8 signal (or tape shell) and defaults to analog audio. (I don't think I have a regular8 tape to test. Yet.)

******

Sidebar: My sleepy grey-matter recalls that HiFi audio is a FM subcarier modulated onto the video wave, similar to HiFi in VHS or broadcast stereo TV. It's pretty good audio, but highly vulnerable to tape dropout and can't be heard in shuttle.


HTH, MPH

I do thank you all for your comments so far, but their seems to some confustion still so here it is again taking your comments into account.

Right lets start again,

The audio is being recorded in stereo on the camera there are two distinct channesl, one with the radio mic and the other the internal microphone. i have checked on the headphones to verify this.

When I play on the Panasonic player (or the Sony Camera) I can hear two channels from the audio outputs. When I connect the fire wire to the PC and record on VV3 I get only the left channel recorded (radio mic), i can see only one wave form, the select RIGHT/LEFT etc are all greyed out.

When the internal microphone is used (which is stereo) or two external microphones are used (via the camera socket)I get the two waveforms on the time line, i can like above hear the stereo channels in the headphones.

I would expect that even if the sound was mono I would still have two channels of audio recorded but identical being mono.

I am strangly enough an electronics engineer by trade and know about PCM and HI-Fi tracks etc, but as to FireWire and the proyocals not a clue, yet....

TIA ZC

Caruso, you say "my Sony CCDV220 camcorder (machine records audio via PCM stereo)" and then say "through my digi8 vidcam to capture via firewire, the result is always two channel containing the exact same audio track "

I would guess your Digi8 Vidcam does not decode or have the facilities to read the PCM audio which is (if I remember correctly) added after the video, as it is layed down on tape, and so as default is reading the linear sound along the edge of the tape (which would be a sum of the left and right channels) and so giving you the mono sound on the fireWire.

I hope that answers your question.

Caruso, you are right to indicate ..
"I assume that there must be some slight difference in the way the original cam lays down/reads the track on tapes recorded in that cam which causes a problem when the newer DV cam tries to read/play back those tapes."

If the mechanism is slightly out of line then the tracking will aslo go so when playing on a different machine it just can not track the tape correctly and as the pCM is on a very small patch on the end of the recoding cycle it is not picked up due to this error, the linear track on the otherhand has no has a wider tolerance and so does get picked all be it with a reduciton in voulme and range, so it tends to sound slightly muffled.

In VHS machines as the heads wear or there is a tracking problem, the Hi-Fi channels start to click on loud noises start with one of the channels first.

ZC

zcheema:

I think I finally know exactly what's happening now. I talked to one of our DV experts (you know, the type who pull out the spec when you have a question <g>), and he pointed out that DV is not just 16-bit stereo or 12-bit dual stereo, but can also do 2 channels of 16-bit mono or 4 channels of 12-bit mono (as well as LCRS surround). SFVidCap only writes a DV Type-2 audio stream for the *first* audio stream. Typically, this is stereo, but, with the right combinations of DV bitflags, it can be mono.

Your camera is being too smart for you. When you plug-in a single external mic, it's saying "well, since I've got one external mic and one internal, these two channels are certainly no longer stereo, so I'm going to mark them as 2 mono streams. If you use the built-in stereo mic, or two external mics, it leaves it as a single stereo stream. When you capture this dual mono file, VidCap is writing the first channel in the DV Type-2 audio stream.

There are some workarounds, but they might be more work than they are worth. Basically, go back to VidCap version 2, which wrote Type-1 DV, load the AVI file into Vegas, let it build proxies (.sfap0) for the audio streams, and then rename the proxies to .w64 and use them as mono soundtracks.

In the future, you might just want to use two external mics, or none <g>.

///d@

Thanks for that SonicDennis, i assumed it might be some spec problem but not knowing the specs was not sure where to look. can you tell me where I can get V2 of the VIDCAP ? will there be any dis-advantages using it from the recent one ?
Will the next version (assuming there is one) be able to bring in two track and or the stereo tracks?
Thanks everyone for your replies.
Z Cheema...