Why does the EX encode 1440x1080 24P like this?
 

Newbie question.

Judging by the Australian literature the SP mode encodes the 23.98 within a interlaced stream that requires pulldown?

Why does the camera do this when presumably the 1920x1080p24 mode is recorded natively to the SxS cards.

Is it to do with getting the stuff off over Firewire?

It uses progressive segmented frame which does not require pulldown. The progressive image is broken into two fields with no time differential so they can pass through the same signal chain that handles interlaced material. On output, the two fields are re-assembled into a true progressive frame.

-gb-

Two questions:

1. According to the brochure, there is no 24p in SP mode.
2. The brochure lists PAL and NTSC as separate modes. Am I safe to assume that the camera released in the U.S. is going to be identical to the camrera released in Austrlia? I ask because The V1U had 24p but the V1P didn't. I'm wondering whether the Austrlian (or PAL in general) release of this camera will remove the 24p capability and therefore the CineAlta badge?

Attached is the part from the brochure that addresses this.

What th Aussie brochure says (in multiple places) is:

"*In 1440 x 1080/23.98P (SP) mode, images are handled as 23.98P and
recorded as 59.94i signals through means of 2-3 pull-down."

So... I guess (and the Sony copy could have been worded better):

1. Full XDCAM HD 1080p24 1920x1080 is recorded as the progressive segmented frame. No pulldown required and will need to be transfered to computer visa card or SDI.

2. SP 1080p24 1440x1080 is recorded in an interlaced stream and will require pulldown (but can be transferred to computer by Firewire). Like the V1U

Really? I guess I'm behind the 8 ball then. Is there a link somewhere to this Australian brochure?

When you say 1920x1080 24p must be captured via card or SDI, I assume you are referring to the SxS card? Or do you mean something else?

John,

The brochure download is in the sticky at the head of this forum.

Vaughan

That's the brochure I saw. It does not say in the specs at the end that the recording modes include 1920x1080 24p in SD mode.

I'll have another look at that brochure. I notice they are labeling HD modes as PAL and NTSC which is bogus. In HD, there is no PAL or NTSC, only different frame rates for proper sync with lighting based on power line frequency.

EDIT: Just re-read it and it does indeed look like they are using pulldown to 60i. That's a bit of a shame because it doesn't increase record capacity when shooting 24P.

-gb-

agre 100% about the non "native" frame recording (ie using pulldown) and its lack of efficiency.
As for teh PAL model shooting 24p (as opposed to 25p) the transport stream itself needs to be able to handle the math.. u cant get 25p from 60i unless ur messing with it in post.
One other thing, and i believe this is the fundamental reason why 25p is not supported, is due to the fact that BluePrint (the BluRay MPG standard) does NOT support 25p, it only supports 24p. Also, 1440x1080 is NOT supported either, in turn scaling up or a shift in the Aspect is required.

Not quite - progressive segmented frame ("psf") is true progressive images delivered in an interlace fashion. So whereas for a true progressive image lines would be delivered 1,2,3,4 etc..... then next frame, for psf *THE SAME LINES* are delivered 1,3,5 etc, ..... next FIELD 2,4,6 etc....., then next frame.

Consequently (unlike interlace) conversion between psf and progressive is simply a matter of reordering lines - not scaling or deinterlacing etc.

For 23.98p, the psf variant is delivered over 60i (so needs pulldown), whereas for 25p, 25psf is delivered over 50i, so no pulldown is needed.

The reasoning is that to a display it presents the same appearance as an interlace signal, and hence is compatible. Better displays should detect that it is psf, not interlace, and treat it accordingly.

Can I get some clarification on this point?

It's confused the heck out of me. Is it possible to shoot 24p (or 25p) 1920x1080 footage to an SxS card and then simply drag it to the PC as a file?

I don't need to capture live via SDI do I?

Yeah... With my V1E 25PsF, I didn't find any such "better display"; unfortunately all HDTVs I tried, treated the signal as regular 1080i and de-interlaced it, resulting in heavy line twitter. The only way to play it back properly has been so far using a software MPEG player with deinterlaced forced off.

Do you know of any "better display" device model that will recognize the 25PsF properly?

In short - no. But I'd expect them to be the more expensive ones!

<snip> Is it possible to shoot 24p (or 25p) 1920x1080 footage to an SxS card and then simply drag it to the PC as a file?

Yes.

Here's a good document that explains all this stuff.

http://www.leitch.com/resources/whit.../Whatis24P.pdf

-gb-

Here is a simple solution. Shoot 720p 24p then you will never have to worry about psf frames and how a digital dsplay that a client has will deal with the footage.

Other then that you will need Blu-Ray authoring tools that will set proper flags on the disc so a Blu-Ray player will output true 1080p. I'm not sure if DVD-it will do that yet or not. The same will be true for HD-DVD. The encoder and authoring software will have to support flags on the disc just like with DVD's.

I've said it once, and I'll probably keep saying it until the day I die. HD is the most "un-standard" standard ever standardized. ;)

Thanks for the link Greg.


-Andrew

So can someone please desrcibe to me what kind of workflow your looking at if you want to ingest 1920-1080 24p EX footage into your FCS without the use of a capture card/HD-SDI or what not? so that the resultant footage is the full rez capture? This will just clarify this whole argument for me lol

AFAIK the EX format is not supported yet by FCS so you'd need to transcode to a full raster codec (like ProRes) to keep it 1920*1080. I've e-mailed my Sony rep w/Q's about an EX workflow but I haven't heard back yet.


-A

Okay well be sure to post that up here when you hear back

Definitely will.


-A

And this is HQ mode 35 Mbit footage?

FCS will support the EX at launch. The importer has been written and I was demoing it at IBC. You open the importer and get thumbnails of the clips (the camera is connected using firewire and File Access Mode (FAM)). You select the clips you want and hit import. The files are imported into FCP as .mov files but without any transcoding and at the full 1920x1080 resolution. The .mp4 files are re-wrapped in .mov wrappers so FCP can handle them but the content is not transcoded or re-compressed so there is no loss of quality and the transfer is extremely quick (6x real time or more depending on the connection). The importer is essentially an improved version of the one currently used to import XDCAM HD material. You will also be able to use the "Log and Transfer" function of FCP to import EX material.

Alister, while we are at "rewrapping" - does the EX1 own application that rewraps MP4's into mxf's use any recompression?

Not to answer for Alister, but the answer is no. MXF is also a container format that includes video, audio, and metadata. There is no re-compression needed.

-gb-

Sony USA isn't making an official announcement about the EX until the 18th so my rep's lips are sealed until then unfortunately.


-A