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Dofray
04-20-2005, 01:21 PM
The first reports on the quality of the images of the HD100 seem very promising. And for the sound ?
Does the camera use compression HDV to record on tape? Everyone knows that the management of the sound in HDV is bad. Does JVC has a solution for stage with that? Also, if one records Direct-to-Disk with uncompressed 4:2:2 or 4:4:4, as is it seems to be possible, the sound also to record on the disc without any compression ?

Barry_Green
04-20-2005, 01:45 PM
Yes it uses compressed audio, same as HDV, so it's 4:1 compression using MPEG-1 layer II.

Future cameras will offer the ability to record uncompressed sound, but not with this camera.


Also, if one records Direct-to-Disk with uncompressed 4:2:2 or 4:4:4, as is it seems to be possible, the sound also to record on the disc without any compression ?
First, the direct-to-disk the JVC offers is most definitely not uncompressed, nor is it 4:2:2 or 4:4:4. The direct-to-disk feature on that camera records the same HDV (or ProHD) stream as would be recorded to the tape, so it'll be compressed audio and MPEG-2 compressed video at 4:2:0.

If you were to set up some sort of external uncompressed hard disk recording station, with a RAID of hard disks and a component analog capture station that could handle 166 megabytes per second of data, then you could capture video without MPEG-2 compression (although we don't know if it'd be 4:2:0, 4:2:2, or 4:4:4 yet). The audio question is a good one. Presumably in that scenario the audio would also be uncompressed, but that's a wild guess.

Gibby
04-20-2005, 04:09 PM
If you were to set up some sort of external uncompressed hard disk recording station, with a RAID of hard disks and a component analog capture station that could handle 166 megabytes per second of data, then you could capture video without MPEG-2 compression (although we don't know if it'd be 4:2:0, 4:2:2, or 4:4:4 yet). The audio question is a good one. Presumably in that scenario the audio would also be uncompressed, but that's a wild guess.

I had a 30-minute conversation with a JVC engineer at the JVC NAB booth this morning. I'll post the results of that, and much more shortly. I specifically asked him if the analog component out on the HD100 was with MPEG2 compression or without MPEG2 compression, and whether it is 4:4:4, 4:2:2, or 4:2:0. His answer was that it is WITHOUT MPEG2 compression, and 4:2:2. I didn't specifically ask if the audio was without compression, but it seems reasonable that it is also uncompressed as it hits the component outs. Good news!!

Gibby
www.cut4.tv

Dofray
04-20-2005, 04:26 PM
Very Good News !!!!
I wait for the results and much more, as you say, of your conversation with this JVC Ingeneer.
Thanks Barry & Gibby