DVCPRO HD bits question.

[Emanuel]

Uncompressed 10bit holds advantages for filmout even if you only shoot with an 8bit codec. Stepping can be introduced in post if, for example you darken a scene. Of course film is analogue and can not be descibed in "bits." For DVD I don't think there is any advantage of using 10 bit unless you were doing multiple generation work on the image. 10bit will obviously retain more information.

Thank you mmm for your concern in answering!

Anyone know if the eye can see a difference between 10 and 12 bit?

Good question?...is there anybody with the answer...[1]

3:1:1 means the colour is recorded at 1/3 the resolution of the luma (black and white).

4:2:2 (same as 2:1:1) means the colour is recorded at 1/2 the resolution of the luma.

Obviously, the nearer to 1:1 the ratio is, the better.

Yes I know but:

http://www.dvxuser.com/V3/showthread.php?t=26672&page=3&pp=10

It really all depends how you read/reduce numbers.
3:1:1 sounds like less than 4:2:2, but it's not.

The Sony has more luma information and the same chroma information as Panasonic
when in 1080i/p. That could be perceived as an "advantage"

DVCPRO-HD (720p & 1080i)
4:2:2 (15:7:7) 74.25, 37.125, 37.125

HDCAM (1080p & 1080i)
3:1:1 (17:6:6) 148.5, 37.125, 37.125

So?...what can we know about this? Is there anybody with the answer?[2]

 

[Shaw]

Of course we could all get reel-stream mods and shoot 12bit, uncompressed, 720p =D

 

[Barry_Green]

So?...what can we know about this?

We can know that it's completely irrelevant. The cheapest HDCAM camera that shoots 24p is $100,000. So how HDCAM works is irrelevant.

Secondly, for you European users, HDCAM has no advantage in color sampling, instead it's quite the opposite, DVCPRO-HD is better. 1440x1080 vs. 1440x1080, but in chroma it's DVCPRO-HD 720x1080 vs. HDCAM's 480x1080. DVCPRO-HD has the same luma resolution and 50% more chroma resolution than HDCAM, in the 50i/25p mode.

In 60i terms, HDCAM has a 10% more luma pixels, and DVCPRO-HD has 25% more chroma resolution. 1440x1080 with 480x1080 chroma, vs. 1280x1080 with 640x1080 chroma.

So, it's all pretty much irrelevant. But then HDCAM has higher bandwidth, about 140mbps vs. 100mbps.

But then again, you *cannot* edit HDCAM on any personal computer, nor can you shoot 24p HDCAM on a less-than-$100,000 camera, so -- it's irrelevant. DVCPRO-HD is directly comparable in quality, yet you can get it in a $6,000 camera and edit it on a desktop computer. So -- why even bother comparing them?

 

[Jarred Land]

i edited HDcam on my desktop.. granted its not a normal desktop, and as Barry said, its hell. Might as well take that 3 month vacation to Africa while you wait for it to render.. and while your there dig up some diamonds cause your gonna need them to pay for the storage requirements.

 

[Emanuel]

Thanks Barry for your anwser and thanks Jarred for your dvxuser.com, as well. (Useful as always)

[PS] The DVCPRO-HD vs HDCAM comparative is very useful for who needs go to 35mm film-out because I know a lot of HDCAM examples but not (yet) even one from DVCPRO-HD.

 

[macgregor]

i edited HDcam on my desktop.. granted its not a normal desktop, and as Barry said, its hell. Might as well take that 3 month vacation to Africa while you wait for it to render.. and while your there dig up some diamonds cause your gonna need them to pay for the storage requirements.

Was that a mac or a pc? how did you capture the video to your laptop?

By the way, is HDCAM always 1440x1080?

 

[izoneguy]

Thanks Barry for your anwser and thanks Jarred for your dvxuser.com, as well. (Useful as always)

[PS] The DVCPRO-HD vs HDCAM comparative is very useful for who needs go to 35mm film-out because I know a lot of HDCAM examples but not (yet) even one from DVCPRO-HD.

I think you will start seeing DVCPRO HD showing up in theaters. Many films have been shot with the Varicam and the DVX-100.
The growth of HD shot for TV is growing on a daily basis.
And I think as you see DVD HD mature the demand for HD shooting will continue to accelerate. Fasten your seatbelts!!

 

[Emanuel]

By the way, is HDCAM always 1440x1080?

Though IANAE*, I think so*!

But not for SR mode (HDCAM-SR as you well must know) that is 1920x1080, 4:2:2 for a bit rate of 440 megabits and 4:4:4 with a double bit rate of 880.

Hope it helps!

*I Am Not An Engineer

*1920x1080 only through upsampling or a pixel shift method (I'm not sure but I already ask it here after Graeme Nattress' quote @post#8 for an enlightenment)

 

[Jim Arthurs]

i edited HDcam on my desktop.. granted its not a normal desktop, and as Barry said, its hell. Might as well take that 3 month vacation to Africa while you wait for it to render.. and while your there dig up some diamonds cause your gonna need them to pay for the storage requirements.

Good gosh yes there are lots of capture cards that will do this... software only editing is a different story, but Blackmagic, AJA, Leitch, Matrox, etc. all make cards that can edit material from HDcam.

As to the storage requirements, different needs for different systems. Pure uncompressed 8 or 10 bit is brutal, but has been doable for many years now. In fact, uncompressed HD NLE was FIRST, while only now are we seeing good compressed NLE's that work in HD.

My system, a Leitch VelocityHD, does both 1080 and 720 and SD. Full raster, meaning true resolution for each format. Uncompressed or compressed. Using compressed, a totally variable data rate! I find approx. 30 to 40 MB/sec looks great for HDcam captures. This is a bit more than the native HDcam data rate, but it's needed because the the card is 1920 by 1080 4:2:2 and not 1440 by 1080 3:1:1.

The tower could set on my desktop, and the AV drives (4 RAIDed SATA's) are internal. The drives will handle two streams of 60 MB/sec with ease, or a single stream of 8bit uncompressed. You can mix compressed and uncompressed on the timeline.

Regards,

Jim Arthurs

 

[Jim Arthurs]

By the way, is HDCAM always 1440x1080?

The format is defined that way, as it is recorded on tape, but the cameras can output full 1920 by 1080 4:2:2 when "live". There is an HD-SDI module/pack that makes a NLE friendly signal.

Jim Arthurs

 

[Jarred Land]

what makes HDcam such a crappy format to work with is that the pipe for moving insists that you uncompress the footage.. so you go from compressed on tape to uncompressed to your comptuter.. its not a constant compression like DVCpro HD.. thats what kills ya, is that temporary bandwidth jump.

 

[Barry_Green]

[PS] The DVCPRO-HD vs HDCAM comparative is very useful for who needs go to 35mm film-out because I know a lot of HDCAM examples but not (yet) even one from DVCPRO-HD.

Well, no, it's still completely irrelevant, because you cannot compare a $100,000 camera to a $6,000 camera! The HVX is not a match for the CineAlta by any stretch of the imagination (even if we nickname it the "MiniAlta" or "VariAlta"). And there is not now, nor will there ever be, an HDCAM camera in the HVX price range. So it's totally irrelevant.

The only way you could make it a relevant comparison would be to shoot on the same camera head, and record to the different formats through HD-SDI (for example, use a Canon XL H1 and pipe the HD-SDI out to an HDCAM deck, or to a DVCPRO-HD deck). In those circumstances I think you'd find the formats roughly comparable, but then again, that would be an extraordinarily silly thing to do -- why use a $50,000 tape deck with a $9,000 camera head?

 

[Barry_Green]

i edited HDcam on my desktop..

How? You can't, unless you're using an XPRI, because you can't transfer the compressed data over, nor is there a software codec.

So you probably used HD-SDI and captured it into another format. That's not the same thing. You can edit footage that originated on HDCAM, sure, but not *as* HDCAM. You can't edit HDCAM on a desktop computer. You'd have to transcode it to uncompressed or cineform or something like that.

Unless I'm totally dead wrong and somewhere along the way they introduced an HDCAM deck with SDTI transfer of the compressed stream, and a software codec... but I'm pretty sure they didn't...

 

[Jim Arthurs]

Unless I'm totally dead wrong and somewhere along the way they introduced an HDCAM deck with SDTI transfer of the compressed stream, and a software codec... but I'm pretty sure they didn't...

You're not dead wrong... but it did happen, and I still have a boardset that can do this... years ago DPS (now Leitch) created an adaptation of their Reality board set, which allowed the direct capture of HDcam codec material to your harddrive via the SDI inputs. VERY similar in concept to editing DV with firewire, only with vastly more expensive hardware

The board cabled to the SDTI out/in of an HDCam deck equipped with the optional SDTI card and there you go... it worked flawlessly, and in fact, made a great way to clone HDCam material simply by transferring it to the hard drive, doing simple edits, then pushing it back to tape. Unless you did an effect or dissolve it was a bit per bit copy. Again, just like DV.

Digital Fusion was the compositing engine for this hybrid, and they re-worked the Sony provided HDCam codec to greater decode/incode speed.

Drackbacks? Expensive license with the codec. Sony wanted, If I remember correctly, $4,500 per licence. Also, good luck finding a HDCam deck where someone has purchased the SDTI board... it tended to be the last of the boards you'd need to purchase, what with the 3:2, etc boards being a priority.

So, the product died a quick death. But it did work, I actually edited material with it, and I have one of only about 19 of them ever sold.

Regards,

Jim Arthurs

 

[Emanuel]

Well, no, it's still completely irrelevant, because you cannot compare a $100,000 camera to a $6,000 camera! The HVX is not a match for the CineAlta by any stretch of the imagination (even if we nickname it the "MiniAlta" or "VariAlta"). And there is not now, nor will there ever be, an HDCAM camera in the HVX price range. So it's totally irrelevant.

Under a tech POV, maybe, but for a indy, maybe not: 1st) If it's possible to shoot a 1440x1080 filmlook with 100mbps as bitrate with a $6,000 camera why spend our money with a 100,000 camera with 140mbps when it can enrich other production fields?; 2nd) If we prefer a $6,000 camera instead a $100,000 (for instance, in the name of that strong reasons) that's why, in the same way, that particular $6,000 camera is enough to our needs without loss the bigscreen@35mm aim. And a comparative like that (with the true-and-tested Cinealta method) can be important in order to say why it's possible to go to film-out without HDCAM but with HVX200 DVCPRO-HD.

The only way you could make it a relevant comparison would be to shoot on the same camera head, and record to the different formats through HD-SDI (for example, use a Canon XL H1 and pipe the HD-SDI out to an HDCAM deck, or to a DVCPRO-HD deck). In those circumstances I think you'd find the formats roughly comparable, but then again, that would be an extraordinarily silly thing to do -- why use a $50,000 tape deck with a $9,000 camera head?

However, under a tech POV, this comparative makes sense but as you're saying, and I can only agree, to use a $50,000 tape deck with a $9,000 camera head doesn't make any sense under a strictly production POV.

Last but not least, a comparative between HVX200 vs XL-H1 will be very useful to all the community that hopes to see it through Barry Green's POV, for 35mm/film-out, as well.

 

[Emanuel]

But there is one thing that I don't understand indeed! Why thisiswells said here:

«It really all depends how you read/reduce numbers.
3:1:1 sounds like less than 4:2:2, but it's not.

The Sony has more luma information and the same chroma information as Panasonic
when in 1080i/p. That could be perceived as an "advantage"

DVCPRO-HD (720p & 1080i)
4:2:2 (15:7:7) 74.25, 37.125, 37.125

HDCAM (1080p & 1080i)
3:1:1 (17:6:6) 148.5, 37.125, 37.125»

What are those values?...if Barry are saying:

«(...) for you European users, HDCAM has no advantage in color sampling, instead it's quite the opposite, DVCPRO-HD is better. 1440x1080 vs. 1440x1080, but in chroma it's DVCPRO-HD 720x1080 vs. HDCAM's 480x1080. DVCPRO-HD has the same luma resolution and 50% more chroma resolution than HDCAM, in the 50i/25p mode.

In 60i terms, HDCAM has a 10% more luma pixels, and DVCPRO-HD has 25% more chroma resolution. 1440x1080 with 480x1080 chroma, vs. 1280x1080 with 640x1080 chroma. (...)»

<PS> For all bits & bytes experts...

 

[pertierr]

This might be a bit off, but still on topic. Here's what concerns me about all these codecs:

DV(25MBps max) encodes 60i(30 frames) regardless of what recording mode the camera is in. On a broad estimate, disregarding audio, you get 25/30=0.83Mbps/frame

For DVCPRO50 you get 1.67Mbps/frame

Now, DVCPROHD 100Mbps always encodes 60 frames, regardless of what frame rate the camera is in. So if it is in 24P, it repeats frames to fit it in the 60P stream. This yields 100/60=1.67Mbps per frame.

That's 1.67Mbps whether it is 720P or 1080P. This is the same bandwidth per frame than DVCPRO50, but there is 2-4.5 times the pixels! For 1080P there is less bandwidth per pixel than there is for standard definition DV.

This is what really worries me about the available codecs in general. Many people only see the "100Mbps instead of 25Mps? wow!". Yet they don't point out how there are twice the frames to encode whether you use them or not, and 2-4.5 times the pixels yielding less bandwidth per pixels than even the standard definition codecs out right now.

One thing for sure, of all the codecs I would choose DVCPROHD anyday, specially over any of the HDV counterparts.

 

[Barry_Green]

DV/DVCPRO25 uses a DCT compression ratio of 5:1.

DVCPRO50 uses a DCT compression ratio of 3.3:1, yielding less compression artifacts, etc.

DVCPRO-HD uses a DCT compression ratio of 6.7:1. So yes, it is about 1/3 more compressed than straight DV is, as far as the DCT portion of the compression system is concerned.

 

[Dahopafilms]

Originally Posted by Jarred Land
i edited HDcam on my desktop..

How? You can't, unless you're using an XPRI, because you can't transfer the compressed data over, nor is there a software codec.

So you probably used HD-SDI and captured it into another format. That's not the same thing. You can edit footage that originated on HDCAM, sure, but not *as* HDCAM. You can't edit HDCAM on a desktop computer. You'd have to transcode it to uncompressed or cineform or something like that.

Unless I'm totally dead wrong and somewhere along the way they introduced an HDCAM deck with SDTI transfer of the compressed stream, and a software codec... but I'm pretty sure they didn't...

... I sense a tremendous and rather uncomfortable disturbance in the Force, Luke ...

 

[thisiswells]

Emanuel-

Thanks for the four PM's you sent me about this thead. And, thanks for quoting me. I'm too busy at the moment to read all of this discussion, but you should really listen to Barry Green. I can't think of single occasion he was wrong about any of this stuff!

Sincerely,
Brian