View Full Version : HD-SDI: 1080i or also 24f?
Emanuel
08-01-2006, 10:07 PM
If there is only 1080i from the HD-SDI offer @XL-H1, can we expect the same setup with the new camcorders or not? That is: 24f (25f@PAL) option available too? Or just 1080i?
If so, the HD-SDI will be limited to the interlaced mode and not also to the progressive one, right? And in this case even if we are handling @800_x_800 lines of resolution, the vertical one will drop 'cause the post-production via will be the only alternative in order to get progressive from the HD-SDI or am I wrong?
Elton
08-01-2006, 10:49 PM
With the NTSC version you have 24F/P carried within a standard 1080i signal via SDI. It has pulldown 3:2 frames but the progressive is there. You can extract the 24p in post fairly easily. With PAL there is no pulldown so it is 25F/P carried in 50i.
Emanuel
08-01-2006, 11:03 PM
:dankk2: Barlow
My doubt is: the signal is interlaced as it happens with the 60i/50i or not?
That is:
1) it's 1080i not 1080/24f or 25f, right?
2) it means we can get the same 24p* or 25p* @post from any 1080i signal as for instance from the Sony Z1 or am I wrong?
* p or f whatever...
The question is progressive:
Aside the uncompression advantage, I want to know if I will buy the A1/G1 'cause its progressive properties (for example I wouldn't buy the Sony Z1 considering it just gives an interlaced capture and simply I don't want it!), the G1's HD-SDI is irrelevant if I just want progressive capture or isn't my point reasonable?
Elton
08-02-2006, 12:42 PM
It's exactly like 24p is carried within the 1080i DVCPROHD standard codec with the HVX. For 60hz users it's a standard 1080i signal that has 24p material carried within the stream. When you capture 24F via SDI you can step through the frames and notice that you have 3 frames progressive, 2 interlaced, over and over again... i.e. standard film pulldown.
For 50hz users 25F works perfectly with 50i capture. It's 25p carried within an interlace signal but it's all stitched together with no frame interpolations.
Is this making any sense now?
Emanuel
08-02-2006, 01:28 PM
:dankk2: Barlow
My feelings are with the interlaced@post. Isn't it the case from the 1080i HD-SDI capture?
If it is 1080/50i or 60i it's not progressive, right?
Like the HDV Z1/FX1 or the new AVC-HD camcorders or am I wrong?
EDIT
See this:
http://www.hdvinfo.net/articles/canon/hv10overview.php
24f or 25f only as playback option.
I'm asking if the HD-SDI is offering progressive as well. Or just interlaced as it happens with the Sony Z1/FX1?
Of course, we know it's possible to go to 24p or 25p @post but this isn't what I'm talking about.
I'm speaking concerning the capture.
If it is 1080/60i (50i to PAL), is it 24f (25f to PAL) too?
Or only interlaced @capture...
...and afterwards we can go to 24p or 25p for sure but only @post? Is that so?
Barry is denouncing the interlaced --> progressive @post. And I can confirm, it's not the same.
Isn't the same result with the 24f/25f from the HD-SDI? Why?
Robert Sanders
08-02-2006, 04:04 PM
The HD-SDI 24P spec on the H1 is identicle to HDCAM. If it's good enough for HDCAM then it should be good enough for the XLH1.
Elton
08-02-2006, 04:25 PM
Emanuel,
You simply extract 24 progressive frames from the 30 fps for 60 hz users. It's not interpolation--it's true extraction of progressive frames embedded within the stream.
This isn't blending fields into frames--it's removing redundant fields from the original 24p material.
Emanuel
08-02-2006, 09:05 PM
What can I say? If it's you -- Barlow and Robert who are saying...
I must be grateful and I am, regarding your attention. Sorry my ignorance but I don't just understand what's the difference between both cases. I thought if we have 1080i we have interlaced not progressive...
In this case, I'm asking if the new pocket cam above mentioned...
http://www.hdvinfo.net/articles/canon/hv10overview.php
...can it do the same 24f or 25f even when they're saying it doesn't!?... Just @post, right? But according my ignorance if it has 1080i as it happens with the HD-SDI offer, it might have it embedded within the stream or my conclusion is so non-logical? Why can't we say it but we can pronounce it about the HD-SDI feature? What's the special feature that scape me by now?
What are the differences? Pardon me if I have been consistent all along, insistant as well. But I'm not a techie and I like to ask when I don't figure out how it works.
:dankk2: in advance my fellows!
Jack_Felis
08-02-2006, 09:30 PM
Sorry, Emanuel, the HV10 can't do 24F or 30F, it can only play them back. The best thing the HV10 will be good for is 1080i filming and as a playback deck for the A1, G1, and H1.
Emanuel
08-02-2006, 10:00 PM
Yes Jack. But my question is what's the difference between not doing the "f" mode and to have it (as 24p whatever) from the HD-SDI embedded within the stream, as Barlow or even Robert enlight us.
If we can say there it can't do 24f/30f/25f mode (situation A) but from 1080i HD-SDI there is true extraction of progressive* frames (situation B). Why? How? What's the difference between both situations?
* "f" or "p" it's irrelevant now that usual debate about if it is progressive or f progressive... (to this point now both are progressives and they are indeed -- period)
...the question is another one.
Elton
08-03-2006, 12:37 AM
Have you ever stepped frame by frame through DVX footage that was shot 24p normal? i.e. you were watching DVX 24p as a 30 fps clip? It's 24p with pulldown frames added for compatbility with the 60i SD NTSC signal.
24F live signal from HD-SDI is the same, only carried within the HD 1080i standard..
robotriderdh
08-03-2006, 10:38 PM
I hope I'm not repeating something someone already said, but I was told today that FCP isn't compatible with Canon's 24f format. Is that true? Also, (this may be a n00b question, but I'm curious) how do you make 60i film look like 24p footage on NLE programs? thanks The new XH-A1 and G1 look incredible, and I'd hate to not be able to use 24f just because i've got FCP.
Elton
08-03-2006, 11:34 PM
It'll be compatible with FCP6 shortly, but there's a fairly easy way to work with 24F in intermediate codec mode, just like people are doing on the PC with CineForm Aspect HD.
Here's the method: http://www.dvinfo.net/conf/showpost.php?p=492340&postcount=7
Emanuel
01-13-2007, 07:20 AM
It'll be compatible with FCP6 shortly(since I'm completely outside from the Mac world) Any update?
Elton
01-13-2007, 08:39 AM
(since I'm completely outside from the Mac world) Any update?
YES! It's called FCP 5.1.2--We've had F Mode compatibility since last Oct.
There's an expected update from AJA that will allow SDI/Analog capture with pulldown removed, but this isn't an issue at all for PAL users.
David Newman
01-13-2007, 10:45 AM
There's an expected update from AJA that will allow SDI/Analog capture with pulldown removed...
Interesting. We use AJA cards and have done real-time 24P pulldown extraction for over a year, it is a standard feature in Prospect HD/2K and Wafian products. I guess AJA is having to do it as the down stream tool vendors (other than CineForm) aren't stepping up to the plate.
what exactly is the difference between standard HD off of a tape or p2 card, compared to this SDI, uncompressed HD?
is it the color sampling? is there more resolution? Im very confused.
David Newman
01-13-2007, 03:01 PM
On a P2 card you will only get one of these 8-bit DCT compressed options : 960x720(up to p60) or 1280x1080p30/i60/24p, 1440x1080xp25/i50. HDSDI is a 10-bit uncompressed interface for 1280x720p60 and 1920x1080p24/p25/p30/i50i60. Both systems use 4:2:2 color sampling.
agwah
01-14-2007, 01:27 PM
HDSDI is a 10-bit uncompressed interface for 1280x720p60 and 1920x1080p24/p25/p30/i50i60. Both systems use 4:2:2 color sampling.
hi david
is it possible now with the new adobe stuff to get a cineform capture from the analog component on a canon a1 into a mac laptop in the field
if so what will be the effective resolution and quality,
will it be vastly different from direct to tape,
will it function well enough for greenscreen and make the a1 comparable to an hvx
what power do the mac need to have and how much data per second is captured MB/s
David Newman
01-14-2007, 10:33 PM
...analog component ... into a .. laptop in the field...
If you can find hardware that does this for a laptop then yes we can compress that in real-time.
agwah
01-14-2007, 11:12 PM
thanks,
guess we are waiting for that one
so uncompressed just means 4:2:2 ??
Barry_Green
01-15-2007, 12:34 PM
No, uncompressed means it hasn't undergone a compression scheme.
4:2:2 is, in and of itself, a sort of compression -- the rawest signal could be up to 4:4:4, although that is really rare in video, you usually only see 4:2:2 at the max.
so the resolution remains the same? quality of image perhaps slightly lessened, and a 4:1:1 color space as opposed to 4:4:4 ? can the G1 produce this? along with the h1?
Barry_Green
01-15-2007, 12:58 PM
Direct HD-SDI output is probably the 1920x1080 image off the DSP, vs. the 1440x1080 recorded by HDV. And it should be 4:2:2 off of HD-SDI, vs. the 4:2:0 of recorded imagery. And it will be 100% free of compression artifacts.
The G1 and H1 can both do it, the other cameras can do uncompressed analog component, the newest crop of cameras can do it through HDMI.
does the A1 have this? ( i always feel so ignorant around you :P )
Barry_Green
01-15-2007, 01:08 PM
A1 can do uncompressed analog output. Barlow just put up a thread here in the last few days showing HDV capture vs. uncompressed analog capture from an A1, you should look for recent threads started by Elton.