Local TV Station Uses P2 DVCPRO HD - Need Conversion Solution for my 700U

[Steve J. Nordahl]

Hi all,

First I love my GY-HM700U, and this question is specific to the file format of a JVC GY-HM700 cam.

My local TV Station uses Quantel's Media Asset Mgmt system for intake and Panasonic Cams with P2 cards, however my first foray with their intake system was problematic. As expected, the TV station intake software did not recognize (right off the card) native 700 codec in either format (MOV or MP4). So I went home, quickly outputted in MOV H264 HD 10.3 mbps after running it through FCP and Compressor and threw the file on a data DVD and gave it to them. The intake system took that file without issue, and it aired later in the day. But I'm concerned about how much quality I may have lost through the conversion process.

Here are my questions:

1. Has anyone else had this problem with TV intake systems (and more specifically Quantel's Media Asset Mgmt system) not recognizing the Native MOV & MP4 formats directly off the SDHC card?

2. Has anyone figured out a workaround to convert either 700 format into files that look the same as what is recorded on P2 DVCPRO HD cards and is accepted by intake?

3. What would be the recommended method using FCP and Compressor to get the best results.

I would like to be able to provide the station with the highest quality I can, and most important the least compressed material that would be closest to the P2 DVCPRO HD format they use that I can.

I would appreciate any help as I would like keep the conversion process down to a minimum and be able to get the material to them quickly in the future.

Thanks in advance,

Steve Nordahl,
Bethlehem, Pa.

[William Hohauser]

I found your problem interesting as I had to work with integrating a new mpeg 2 server system earlier this year. Quantel's web site is quite out there in terms of clear inforamtion but if I read it correctly their sQ server can only take MPEG IMX, DV, DVCPRO and AVC-i formats. Fortunately it seems that DVCProHD is in the mix so that's the format I would use in Compressor either to convert the footage directly or the final edited sequence in FCP.

Strangely, elsewhere on their website, they have a facility called Mission, a "holistic" media system (Quantel's words) that indicates that it can take XDCAM files. Perhaps you are giving them a frame rate or data rate that their system can't take. These media management systems can be quite a bundle to get used to but once a system is arrived at they can work great.

[Steve J. Nordahl]

Thanks William,

I think I'll try your suggestion and output in DVCPRO HD and see how it goes. It would be nice if I could somehow utilize the XDCAM codec, but for now, at least I know the H264 HD in MOV worked, so I have that as a backup.

Thanks again and have a Happy New Year...

Steve

[Robert M Wright]

If they can take AVC-Intra, that would work better than DVCPRO HD. DVCPRO HD will knock 25% (or more) off your luma resolution, and isn't nearly as efficient as AVC-I (image quality at a given bitrate).

[William Hohauser]

Depends how the footage is to be utilized. If it a finished piece that will be cued for playback only then AVCi should work fine. If they intend to edit it and integrate it with other work DVCProHD probably will work better. It really all depends on how the system is set up.

My understanding is the AVCi comes in two bit rate types; 50 which is 4:2:0 just like HDV and 100 which is 4:2:2 just like DVCProHD. DVCProHD uses a slightly lower line resolution than normal HD but it works fine. There is a new AVCu (or Ultra) which can do 4:4:4 but only at 24p and I haven't heard about which equipment can even play it. Regardless it's likely that if the Quantel system can play DVCProHD it can play AVCi 100.

[Robert M Wright]

I don't know that the difference in resolution is all that minor. 1080 line DVCPRO HD is 1280x1080 luma (720 line is 960x720 luma).

The broadcast will be 4:2:0 color, so if it was me, I'd even choose the 1080 line 50Mbps AVC-I "lite" vs 1080 line DVCPRO HD. Remember, the chroma takes a hit with DVCPRO HD also. It might be 4:2:2 color, but it's only effectively 640x1080, not 960x1080 (like full raster 1080 line 4:2:2 - and 540 of the lines of chroma on the vertical axis get whacked for broadcast anyway). Don't let the "lower" 50Mbps bitrate of AVC-I "lite" throw you off either. AVC-I is roughly twice as efficient (image quality wise) as DVCPRO HD, so it's not really lesser quality (aside from lower, but not as much as you might think, chroma resolution). Full 100Mbps AVC-I really should just blow away DVCPRO HD.

[Robert M Wright]

Another thing to keep in mind is, that what you shoot with the HM700 is recorded with 4:2:0 color (full raster), unless you use a nanoflash or something.

So, unless your editing process yields 4:2:2 material, and actually results in making the extra lines of chroma significant (like perhaps with a spatial noise reduction filter, for example), then delivering the footage encoded as 4:2:2 color really doesn't do anything at all for you, thus even going with 4:2:0 AVC-I "lite" wouldn't hurt you with the chroma resolution anyway.

[William Hohauser]

A question regarding AVCi and Final Cut 7. I know about the ability to ingest AVCi but do you still need to purchase a third party plug-in to export AVCi?

Depending on the sort of editing needed, I agree that staying in 4:2:0 will work fine.

The DVCProHD resolution issue stems from times when many were told that HDV was unsuitable for HD broadcast which DVCProHD was totally acceptable. Even now some networks put a limit on how much HDV is used in a program. I wonder how they feel about XDCamEX?

[Robert M Wright]

I'm not sure where you would get an AVC-I encoder - never looked into it (probably Panasonic, but might cost a pile of cash), although if you knew the specs for certain, heck you could probably get AVC-I lite complaint streams out of x264 pretty easily (and x264 is a very good encoder - actually used to outperform the much pricier MainConcept H264 encoder a couple years ago, but MainConcept has improved there's a bit and now edges out x264 a little). As far as I know, neither x264 nor MainConcepts H264 encoder can produce 10bit 4:2:2 encodings, so they couldn't really do full bore AVC-I complaint encodings.

From what I've gathered, mostly from reading war stories right here, it would seem that a lot of folks making decisions, on what gets accepted for broadcast, simply are not knowledgeable enough, or perhaps competent enough, to make such decisions very well at all.

If HDV is not edited, it's actually pretty dang close to what will be broadcast out over the air. I think I read somewhere that anamorphic 1440x1080 MPEG-2 is valid for broadcasting (assuming it is otherwise proper), but I could be wrong on that (never really checked to be sure). If it is valid, I've got to think it would not be tough to write software to simply reduce the bitrate of 1080i60 HDV recorded footage, without changing motion vector information at all, putting a relatively minimal hit on degradation from a single re-encoding (what Nero has got to be doing with their zippy recode stuff for DVDs - works quite nicely, and is also very fast due to no need for motion vector searching). If you shot news, as if shooting "for dailies" (and got it right) with an HDV camera that has a good imaging block (like perhaps the Canons), I've got to think HDV might be very useful for low-budget, almost live, news gathering (perhaps quite ideal for live broadcast, for that matter, since the re-encode should be pretty easy to accomplish in real-time, with relatively little CPU power - a fast modern laptop could might even be able to do it with efficiently written software - and still probably get better quality than with a really pricey hardware broadcast encoder, re-encoding from scratch, doing motion vector search all over again).

Also (not to knock the HVX200), apparently some broadcasters would sooner take DVCPRO HD coming out of an original HVX200, than other footage recorded using "inferior" formats, coming from camcorders that record just a far and away superior image overall. I mean really, would you rather have noisy 1280x1080 10bit 4:2:2 recorded footage, shot with dang close to SD CCDs leveraged to the hilt with pixel shifting technology, or EX1 footage??? I know I've read of EX1 footage being rejected, because of 4:2:0 color, while being slighted as essentially no better than HDV. That's really pretty silly, when you carefully consider the merits. (A similar approach, to what I outlined above using HDV footage, could easily work very well with EX1 footage, and at 1920x1080 to boot even. If I ran an OTA television station, broadcasting 1080i60, the news crews would probably be running around with EX1s or EX3s, not HPX300s, and certainly not 1280x1080 DVCPRO HD only cams, and take lessons on "shooting for dailies" if needed.)

It's also occurred to me, after seeing what an HMC40 can do, that a lot of footage out of that camera, shot in ideal conditions, would likely just blow away footage from a camera like the original HVX200 (especially when broadcasting 4:2:0 color anyway - at full raster though), but guess which footage would likely be accepted by just way, way more broadcasters.

Any OTA TV station owners out there want to hire a consultant, to considerably improve their screening process for accepting footage for broadcast, as well as improve camera purchasing decisions??? Even at the shockingly obscene (er, uh, I mean reasonable) rate I would bill out at, you would almost assuredly save a nice pile of money, and get better looking broadcasts to boot! :)

You know, when you get down to it, cable networks could probably do a whale of a lot better at making decisions on what footage to accept also. The realities of what cable and satellite operators do to video prior to "broadcast" presents some entirely unique (notably different from OTA broadcast) issues that should certainly be considered when making those decisions.

[William Hohauser]

Here is a plug-in for AVCi exports: AVC-Intra QT
I have no experience with it.

[Robert M Wright]

I don't think I'd purchase that plug-in without a trial, or at least knowing more about that particular codec (like who developed it). It might be really good, or it might junk.

I was thinking Edius 5 probably can export AVC-I, and just checked. Apparently it does (see link below), and every encoder that comes with Edius that I've tried out works pretty dang good, but Edius does have a tendency to be rather limited, essentially to what is useful for DVD, Blu-Ray or broadcast applications, which is probably a good and a bad thing.

Personally, I'd like to have options for much less conventional encoding also, but by limiting the options I'm sure they made it much more practical to develop their software affordably, with the rock solid performance Edius tends to deliver quite consistently (it just don't crash hardly at all). I'd like to be able to encode with Edius, for web video, but they don't let you do H264 MP4s at low enough bitrates. Otherwise, their H264 encoder seems to perform quite well, from what I've tried (not a whole lot, but I've thrown it some reasonably challenging stuff, and got good results).

I would suggest Edius 5, if a PC is available for encoding (rather than purchasing an AVC-I plugin from a vendor I know nothing about). It's probably available with the 30 day trial version of Edius 5, although I haven't used it in quite some time. I use Edius Neo 2 (suits my purposes quite nicely). The few things that aren't available with the trial version of Edius 5 tends only to be features that involve third party licensing issues (essentially Corel's Blu-Ray authoring stuff), which I doubt would affect the availability of AVC-I encoding.

Of course, if it has to work on a Mac, Edius is probably not the way to go, although you might be able to use it with a PC emulator - no idea - haven't hardly touched a Mac since the 80s. I'm sure Macs work very well for a lot of folks, but for me, especially building my own hardware, and knowing PCs so well for decades of working closely with them (both hardware and software), it would take me years and years to become as comfortable and productive with a Mac as with a PC.

http://www.grassvalley.com/docs/Misc.../PRV-3062M.pdf

[Robert M Wright]

Come to think of it, I bet Edius 5 probably would work with a PC emulator on a Mac just fine. The way Edius is designed to be so reliable on just about any PC hardware (within reason), makes it seem pretty likely. I'm sure it would run slower, so the encode might take awhile, but I'd sure give it a shot (especially if it's just a one time thing).