Slightly OT- reel-stream for HVX-200?

[Barry Green]

[Brian Wells] “But Barry.. The DVX100 also has “uncompressed output” as well.
It’s done over the S-Video connector.
Analog HD Component isn’t any different in that regard. “

Not necessarily true. Has anyone verified that?

Back in the old Sony VX1000 days there was much argument over whether the s-video port would be better for chroma keying. Eventually an engineer traced the schematic and proved that the s-video was coming after the DV compression. S-video output, at least on the VX1000, was post-compression.

I don’t know what the status of today’s cameras are. They may be pre- or post-compression… we’ll have to figure out a way to test it to tell for sure. But I wouldn’t just assume that it was.

—————–
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[Christopher S. johnson]

Emery,

Well, let’s leave that up to me, OK? If the S-video port is uncompressed, I might do a live switch between two cameras, feed into a DV deck and then I will have only used the DV crunch ONE time instead of TWO. S-video is not the worst thing in the world for budget production. Multiple DV compressions is.

I was asking a question to my peers here in this thread and it appears that they do not know the answer. Its not a common question. But I do need an answer. Any suggestions?

-Christopher

[Graeme Nattress]

You can also get gear that will live-switch the Firewire DV stream and thus again only have one DV compression.

Graeme

– http://www.nattress.com – Film Effects for FCP

[Emery]

Hey Christopher, your right… I dont know exactly whats comming out of the s-video on the DVX, but its a composite signal. Its definitely not the best solution. As Graeme suggested you could use a DV switcher.

Emery

[Carlos]

I have used the firewire Datavideo switcher with three cameras and the live edited version looks as good as the master tapes. It works very nicely.
Carlos

[Brian Wells]

I suppose my comment was made with the impression that all DSP in a camera is performed at the same point in the chain and that if you’ve got white balance on output, then you’ve also got chroma sampling, characteristic curves, etc.

Perhaps I have a fundamental misunderstanding of the HD component outputs on the FX1/Z1 and HD100 camcorders. I thought they were outputting 4:2:0 sampled footage and because it was coming out of an analog connector, you could call it “uncompressed” the same way Media100 calls DV editing “uncompressed” or the same way any other editor works “uncompressed” Says nothing about the raw material but only about the way it’s recorded.

Do I misunderstand the analog output of a HDV camera? Just looking at it, it doesn’t appear any more “uncompressed” than if one were using DV, but then I haven’t verified this either. Please advise.

Thanks,
Brian

[Toke]

I’m getting a bit puzzled also.
Isn’t all analog component “chroma compressed” ie. chroma channels have half the bandwidth than what luma has?

[Deleted User]

[Brian Wells] “… Do I misunderstand the analog output of a HDV camera? Just looking at it, it doesn’t appear any more “uncompressed” than if one were using DV, but then I haven’t verified this either. …”

Hi Brian: It depends on the design of the camcorder.

For example, Sony’s techs in NJ tell me the Sony DSR-390 and DSR-570WS DVCAM camcorders output “live” (not from tape) analog component video which does not have DV compression applied to it. This “uncompressed” analog component video is 10-bit 4:2:2. It’s not 36-bit 4:4:4, but it’s much better than DV-compressed 8-bit 4:1:1 (NTSC) video. (I didn’t ask about the s-video outputs of these cams, regrets.)

I suspect other camcorders route video signals in various ways. I suppose the senior techs at each manufacturer’s “home” office aren’t necessarily infallible sources of this information, but it would seem a good place to start.

All the best,

– Peter

Just a friendly reminder to all: Please consider filling-in your COW user profile information so we have a better idea who you are, where you’re from, and so forth. It’s the friendly thing to do. Thanks!

[Rennie Klymyk]

[Brian Wells] “But Barry.. The DVX100 also has “uncompressed output” as well.
It’s done over the S-Video connector.
Analog HD Component isn’t any different in that regard. “

It’s possible that it may not be compressed on certain cameras but s-video is chroma/luminance, the 3 primary colors have been mixed, whereas DV at least retains component color signals.

[Brian Wells]

Peter,

Thanks for clarification on the Sony cameras you mention. Whether or not the DVX camera has a similar signal routing, this pretty much confirms my fundamental understanding of how “it could work”

The talk of “uncompressed” output from a HD100 (I only mention this specific camera because of the limitations of not recording 60p to tape, for no other reason.. This looks like a nice camera, okay) seems to be “talked-up” per say as a “groundbreaking” feature that seems to have been there all along in (at least some) DV camera products.

I’m definitely not into hype and I’m glad to have confirmed that “uncompressed” output on a DV or HDV camera is not a “groundbreaking” feature as has been illuded by certain folks.

Looking forward to great things in digital video this coming year!

Best,
Brian Wells
Texas

PS. – I’ll try to update my Profile on here soon. Thanks again, Peter.