HDV format- audio recording on HDV cameras

According to the specs for the HDV format standard the audio is recorded in
2 channels using MPEG-1 Audio Layer II (48kHz, 16bits).

Unlike most other digital video tape formats in the last 10 years this is
not PCM digital audio. This is a lossy format using perceptual masking
techniques to eliminate frequencies.

There are 4 new cameras many of us will come into contact with in the
documentary and low budget narrative world. the Sony HDR-FX1 (prosumer
version/& ? model pro version) and the JVC GR-HD1 and JY-HD10U.

With the $3,700 price tag for entry level HD video the Sony HDR-FX1 prosumer
version also only has 1/8" audio input (need a Beachtek box for XLR in), and
even the "pro" version uses the HDV format with the lossy audio. even though
the "pro" version will be less than $7,000. The 63 minute tapes cost $17.

This format is NOT going away. It is a cost efficient entry-level into High
Definition video. Unlike the Sony VX1000 back in 1997 that started change
video production (although it was only 12bit 32kHz audio), it was PCM audio.

With this lossy audio built into the spec we as sound recordists at least
have additional leverage to push for the primary audio recorded double
system uncompressed PCM audio and a scratch track for editing sent via
Comtek with 1/8" jack plugged directly into the camera.

Since its lossy why bother sending a pristine wireless signal as a scratch
track?

With this MPEG-1 Audio Layer II spec can we strap a sync box to the camera
feeding timecode to the other audio channel? (via Beachtek box split for
audio and TC) or will it be unreadable after its recorded? As we know it
will not work with a lossless format like Minidisc.

comments are welcome to start a discussion on this new format.

-kspaz

"Earthlink" <undergroundvision RemoveThis @yahoo.com> wrote in message news:<OnNid.868$_J2.31@newsread2.news.atl.earthlink.net>...

> With this MPEG-1 Audio Layer II spec can we strap a sync box to the camera
> feeding timecode to the other audio channel? (via Beachtek box split for
> audio and TC) or will it be unreadable after its recorded? As we know it
> will not work with a lossless format like Minidisc.

TC sent to one channel *should* be readable. HDV's MPEG-1 Layer 2
isn't *that* lossy. It's 4:1, I think.
However, my engineering friends say the codec probably compresses both
channels of audio together and assumes they'll be a stereo pair with
similar audio content. So the scratch track might have some ticking,
buzzing, or pumping. But might still be usable as a scratch track.

With HDV's long group-of-pictures MPEG images, though, I wonder how TC
slates would look.

I should have an HDV camera in hand within two weeks. I hope to find
out more about how it can work with double system.

Of course, if someone knows now, please chime in.

Jim Feeley
POV Media