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-   -   Filmmakers: want to try a PCM recording? (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/55209-filmmakers-want-try-pcm-recording.html)

Steve Mullen November 29th, 2005 04:39 PM

Filmmakers: want to try a PCM recording?
 
Someone with a portable mixer than outputs a Line-level signal to an XLR plug might want to try the following if they are interested in using the HD100's single PCM channel.

Right now -- it sounds like Channel 1 is being amplified from MIC level to Line-level and then this signal is being fed to the MP2 encoder AND fed back into the DV circuit which then again amplifies the signal from MIC level to Line level and then to PCM. The signal is very distored.

In other words, the HDV and DV are handled by two separate circuits. And, both respond to the MIC/LINE switch setting.

If I'm correct, an audio mixer can be used to input a Line-level which would, of course, NOT need to be amplified. (The switch would be set to LINE.) Then the signal would not be re-amplified in the DV circuit.

If someone tries this experiment, post, and I'll post instructions on how to get the PCM channel out.

By the way -- only Channel 1 is recorded to PCM so only input to #1. You can, however, connect the built-in Mic or another Mic to Channel 2. Both #1 and #2 are recorded to HDV.

If this works, it is a perfect solution for filmmakers!

Andrew Young December 3rd, 2005 06:48 AM

Steve,

I have the mixer and would like to do the line level test, but I can't get PCM out for the life of me. Please post what worked for you.

Steve Mullen December 3rd, 2005 08:25 AM

PCM Audio Capture from HDV Tapes

To capture this PCM audio, set the external HDV/DV switch to DV when the camera is powered off.

Now turn on the camcorder and set PB TAPE to DV, select VTR mode, and press PLAY.

Ignore the HD100ís warning.

Now start capture of 48kHz DV.

When HDV is output (PB TAPE set to DV) the MPEG-2 data will be recorded as though it were DV data. Of course, no image can be obtained from this data. It will appear as colored confetti.

If you have the option, you should disable recording video when capturing DV. This will result in an audio-only recording that requires far less storage.

Thank you for trying this!

Steve Mullen December 7th, 2005 07:06 PM

After much work -- thank you -- Andrew found distortion on PCM no matter how audio was input.

So although PCM is present and can be captured, the fact it is so distorted makes it unusable.

PCM must be there for a reason. But, somewhere JVC messed-up. Feedback to JVC has been made.


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