Real 1080 24p @ 4:2:2???

[Douglas Spotted Eagle]

Originally Posted by Heath McKnight

John B.,

Converting HDV to 4:2:2 is a good thing, trust me. Besides, it's pixel-shifting 960x1080 to 1440, then you output and it pixel-shifts again to 1920 on those displays. And it's clean. I like working with captured footage at 1920 and it apparently looks great!

heath

Heath, the camera doesn't pixel shift; it acquires pixels at 960 x 1080 on the sensor block and interpolates, stores them at 1440 x 1080 on tape, and then displays them at 1920 by 1080 at a PAR of 1.333.
However, you're right; acquiring at 4:2:2 short GOP or no GOP vs acquiring at 4:2:0 long GOP provides for a better editing experience in almost all situations. In fact, even though it's 8 bit data, capturing at 10 bit and editing at 10 bit provides a much better and malleable image. This is why many pro's capture with an AJA, Bluefish, or BMD card instead of using firewire. Additionally, you avoid the software decode of the .m2t on your computer, which has an impact on the quality of your image.
You might recall the 4:2:2 Sheer video images compared to the Firewire images we had on the HDV tour. The 4:2:2 ingest is significantly more robust when pushed than is the 4:2:0 image.
Another way of looking at it is that *every* NLE developer has an intermediary codec available for HDV content. Some won't allow editing of HDV without the intermediary. There is a reason they spent the time/money to develop the intermediary.
It's a better output and editing experience.

[Mike Gorski]

Yeah I read that it just scans twice and literally puts the image together which makes a 1920X1080 image with 4:2:2 color space before any kind of compression. That HDMI port is looking nice.

[Bob Grant]

Sorry but I can't see the advantage of capture HDV via anything apart from firewire, other than speed.
The HDV capture gets you a bit image of what's on the tape, from there on you can convert that to anything / apply chroma tweaking etc without the need for large, fast RAID drives.
On top of that the mpeg-2 has to be decoded somewhere, either by a VCRs hardware or in the PC's software, one is forced to do it in realtime, the later has all the time it needs to do the best possible job.
I'm not questioning the value of using a DI, just how you get from HDV to the DI. Sure decoding the HDV in a VCR's hardware to 10 bit 4:2:2 and feeding that down HD-SDI is going to give you a faster workflow than capturing native HDV and convertering to 10bit 4:2:2 in software but doing it in software would be a heck of a lot cheaper and could yield even better results.

[Douglas Spotted Eagle]

Firewire is definitely cheaper, and arguably easier. If you have a DR60 or similar, it's significantly faster, too.
However, capturing via an AJA Xena, there is some chroma smoothing that takes place, which is entirely subjective, of course, but I prefer it.
For full-length and/or dramatic projects (yeah, only done a couple with the V1) it's a sweet look.
If it's just a fast capture, edit, spit it out, we use the Firewire and/or DR60 to transfer the footage. The content we're spitting out to cable providers such as ESPN etc are all just firewire captures, printed to either HDCAM or on data DVD as one of several file formats.

[Michael Liebergot]

Originally Posted by Douglas Spotted Eagle

he content we're spitting out to cable providers such as ESPN etc are all just firewire captures, printed to either HDCAM or on data DVD as one of several file formats.

Spot, are you using an intermediary codec like Cineform or edting staight captured HDV on the timeline? And also, are you using Vegas, FCP or both.

I am looking to make the switch to FCS2 from Vegas, as I just received a new 2.66 Quad core MACPRO. And I was wondering about capture and conversion in FCP in regards to HDV video. And if I would need a intermedairy codec or can edit straight HDV footae on teh FCP timeline. Of course this will be the new FC Studio 2 verison which isn't released yet.

And just so you know, I will be running Bootcamp and Vegas/SF9 on Win XP.

[Heath McKnight]

Spot,

Thanks for correcting me! I need to brush up on the still-new ClearVid technology.

heath

[Steve Mullen]

"mpeg-2 has to be decoded somewhere"

Bob's 100% correct which is why the post-HDV compressed capture path is very different than the pre-HDV compressed path.

Once you get Bob's point, the issues become two-fold: WHEN and HOW.

WHEN:

1) In camera
2) During capture to intermediate
3) During editing

The earlier you do it -- the bigger the source files and the greater the disk bandwidth load on the computer.

But what about 10-bits? Totally irrelevant with FCP. If you want to work with 10-bits -- use FCP 10-bit mode. The video information is neither enhanced or preserved while waiting to be used, if its stored as 10-bits.

But what about 4:2:2? Again totally irrelevant with FCP. FCP always decodes to 4:4:4 internally. Once again, video information is neither enhanced or preserved while waiting to be used, if its stored as 4:2:2.

But, what about the "difficulty" of editing long GOP video? This is a trade-off: yes more CPU cycles must be used to decode on the fly. But, on a laptop, CPU cycles are very available. What's not available is the much greater storage required AND the need to move this rapidly. That's why CineForm warns that unless you want to be disk-bound, you need a RAID.

But what about the re-compressing FX to HDV. This myth has no basis. MC and Xpress Pro both force all renders to DNxHD. FCP never re-uses renders for the final output. Color has an option to render to ProRes rather than HDV.

HOW: this is the real issue. How good is the decode, the upsampling to 4:2:2 or 4:4:4, and the conversion to 10-bits if wanted. And, do some methods tweek the chroma better. If i had raised this issue, it would be called "measurbating" because we have no real way to measure the claims. :)

However, interlaced MPEG-2 does have inherent chroma issues that can be solved various ways. So, it's possible for different decoders to output video that looks different.

Bob assumes that software may do it better than software. But, Apple has long been known to do a bad job -- at least for AIC. CineForm has long been known for doing a very good job. Avid, may or may not do a good job. I'll bet they do a good job.

So there MAY be a "quality" advantage to using something other than native HDV, but it's not for the reasons usually posted.

If you edit long form with MC and Xpress Pro, there is a huge reason to stay native. Both MC 2.7 and Xpress Pro 5.7 support Smart GOP Splicing. No need to wait for conforming before exporting HDV. And, since the BD and HD DVD creation software imports HDV and places it -- without recompression -- on optical disc, it means you have a very fast way of distributing HD versions of your project during production.

Bottom-line, all the measurable issues favor native HDV editing. Others can measurebate on the "quality" issues they see.