HDV to DV Conversion
 

I'm stumped. I need to make DV backup copies of some HDV footage.

My Source:
- JVC HD100 playing a 720/30P/HDV source tape.
Menu Settings:
- PB Tape > Auto
- PB Output > NTSC (have also tried 480P [my next guess], 720p [which doesn't make sense] and 1080i [which also makes no sense at all for a dump to DV]
I have aslo set the IEEE-1394 switch to DV.

I have tried using an HVX200 (in DVX100 Mode) as a Recording Deck.
No Luck.
I have tried all kinds of variations of settings on both cameras.
No Luck.
I have also tried using a Sony Z1U as a Recording Deck.
No Luck.
I have tried outputting the signal to Sony Vegas Video (instead of a camera) just to see if the darn thing is working at all.
No Luck.

In all cases, the HD100 flashes "CHANGE 1394 SWITCH"

So I try it out, against my better judgement, switching the HD100's 1394 Switch to HDV.

In this mode, my Windows machine recognizes there is a new device and procedes to install it. (Albeit an HDV device, not DV).

Also, in this mode, the Sony Z1U recognizes SOMETHING attached to the other end, but warns: "No output image in 'VCR HDV/DV'. Change format."

I simply need to make a DV Dub from HDV (HD100/30P) footage.

Any thoughts?

Hi Clark,

I am probably completely wrong but I think you might have to transcode the HDV footage to get a DV copy to tape as they use different types of compression. However, you could probably record an SD version to tape by playing the footage through a standard definition monitor and recording that (maybe) although you obviously wont have all the HDV indfo there but then again you wouldn't with the DV copies either. Also just wondering if you couldn't back up in HDV like for like after all it takes up the same amount of space (more or less) on mini DV tape. Sorry this probably doesn't help much, hopefully some of the others will chip in.

Regards Greg

You cannot use the camera or the BRHD50 deck to down-convert HDV1 to DV via firewire as you can with Sony HDV2 gear, so stop trying! You would need to capture native HDV to an NLE, transcode and then output to DV via firewire.

As Greg says, the only fast and simple way to down-convert with hardware (camera or deck) is via analogue (component is best), which is not a great solution, of course. If you have the HD250 or the Convergent interface you could go via SD SDI into a pro DV deck with SDI input, which would be much better. There would still be a decompress to baseband SDI and recompress to DV but at least there would be no D to A to D and the introduction of analogue blanking and possible timing errors.

That makes sense to me. Now I'm curious, how does the Canon XLH1 acheive DV Downconversion straight from the camera? I can shoot in HDV and then capture DV or HDV without doing the transcode you mention.

Hi Clark. I know - it's very frustrating. I couldn't believe it when I found that out! The Sony HDV2 gear is capable of down-conversion via firewire and I'm interested to hear that it is possible on the Canon hardware as well. It's another aspect (the first being poor NLE support) that makes post for HDV1 pretty frustrating.

It's not overly complex. JVC simply didn't include that feature on the HD100.

maybe not complex, but a good downcoverter does require some processing for a nice picture. a quick scale operation will not look so good. FWIW, you are aware that the data rate of HDV 720 is only 2.5mb/sec, DV is 3.5, so it generally does not make sence to

1. increase your data rate by going to DV
2. take an extra compression hit, losing quality go to DV
3. have to match back to HD in the end

much better just edit in HD, the downconvert your final. the kona cards will do decent HD->SD downconversion, the matrox MXO does excellent downconversion, and plays nice with FW audio interfaces


Steve Oakley

Hi Antony , which Sony HDV2 gear is capable of down-conversion via firewire? (not component)

Thanks,

Johnnie

For one the Sony Z1u will.

Here is the brochure. Look under Downconvert for the possibilities. Through component it will also downconvert to 480p.
http://bssc.sel.sony.com/Broadcastan...613_HVRZ1U.pdf

I don't know about the FX1 or the new V1u.

If you have a Mac then the MXO looks like a really interesting product...

http://www.matrox.com/video/products/mxo/home.cfm

Sorry my mistake...sure the Z1 can do this...

Still looking for a one VTR or camera that can down convert HDV 1 and HDV 2 to DV via firewire

Yep, the Z1 and the companion VTRs can do this. I'm not aware of any VTR that can handle both HDV1 and HDV2, let alone down-convert both via firewire. It would be great, though.

Oh, and HD/SD SDI out together with RS422 control would be nice, too. And yes I know you can have this with the Convergent and Miranda boxes!

Antony,

how would you make AXP work with either of the Convergent and Miranda boxes? Is there a way of getting the m2t files converted on ingest to one of the DNxHD formats? As far as I am reading into it both convertors use 1394 as input but SDI as output, which I guess wouldn't work with AXP, would it? Am I missing something here?

On the upside, if there was a way to make this work, either of the boxes would provide the missing link in the AXP chain bu giving the user an HD component client monitor.

Hi Jiri

If you have the Convergent HDConnect LE (not the SDI-only or HDMI-only cut-down versions) you can capture down-converted HDV via SD SDI into Mojo SDI or down-converted SD analogue component into analogue Mojo. Since AXPro has no HD i/o the HD SDI and HD component features on the Convergent are not much use for ingest. They only come into play if you have Symphony Nitris or Media Composer Adrenaline (not Soft) plus the DNx board, both of which give you HD SDI I/O, as you know. Of course, Symph Nitris gives you the option of capturing to uncompressed HD as well as DNx. I believe the current HDV architecture of AXPro does not give realtime HDV output via firewire (as per standard DV solutions) from a HD timeline, so the Convergent box won't help you with your HD client monitoring.

With FCP, you have many hardware options for HD monitoring, of course.

The only affordable HD client monitoring solution that I can see might be possible for us with AXPro is the nVidia Quadro FX 1500 card, with HDMI third head. I know that colour represention is not to be trusted with such solutions but it might be good enough for client monitoring. Has anyone tried this?

Well...that would be nice. Where did you hear/read about this possibility Antony?