Does P2 support AFD?

mikkowilson

mikkowilson

Steadi-Guru
Probabaly a question for Jan or Barry, however maybe somone has tested and knows.

Does (and if so, which gear) P2 support AFD (Active Format Descriptor)?
http://en.wikipedia.org/wiki/Active_Format_Description

We are about to adopt it as a station format, and it would be great to know if stuff like the HPG20 could be used to store programs with the AFD codes intact.
..and if it's a metadata field that could be edited (or even set by the camera automatically), that would be awsome!

- Mikko
 
No expert on that, but as far as I know AFD isn't any sort of metadata, it's encoded in the video signal like closed captioning. So if your video equipment is generating or inserting AFD, then P2 should be able to record it. But... yeah, I should defer to Jan, because I don't really know.
 
In a live stream of video (such as HD-SDI), AFD is carried as "ancilliary data" in the vertical interval, like digital closed captions and also like Embedded Audio.
Basically it is "embedded meta-data" in a video stream.

Most recorders strip the embedded audio to a seperate stream(s). Closed captions are often recorded as part of the picture information, though sometimes also decoded to a seperate stream (such as when beeing transcoded to MPEG2 where captions are a seperate data stream).

So it depends on the P2 ... and probabaly more accuratly the DVCPRO and/or AVC-Intra ... format(s) and the recording & playback equipment as to whether they record AFD as part of the video, as metadata into the MXF structure or not at all.

...And if P2 can/does carry AFD; it would be really cool if the cameras (and other recorders) could insert that data during recoding based on the recording format and a user preferance (for example if 16:9 material is beeing shot "4:3 safe" or not). I realize this might be more in the way of a feature request, but it could sure be a handy firmware update for us TV folks.


- Mikko ... is feeling a little nerdy after typing this post.
 
I can't speak for Panasonic but I'm going to guess as AFD is a new technology and sounds like a signal that an MPEG encoder/broadcaster must specifically run that it's not recordable as part of a regular video signal and thus would not be something P2 would pick up. But sounds like it's not meant to either as this is a signal designed to be encoded at the broadcasting/final output level not the capture stage. I imagine it is not designed to survive through editing, etc. It would be a real mess to try and mix footage that says it's 4:3 safe into a 16:9 edit- for sure I've not seen any sort of implementation of this spec in Avid/Premiere/FCP so I think it's a broadcaster thing, not a camera thing.

-Noah
 
It is primeraly a broadcaster thing yes, however - at heart - so are cameras. And P2 is much more than just cameras.

I agree that in a lot of production environments there's no need for a camera to put in AFD codes. - However the concept behind AFD beeing that the formatting specified by the creator (which means shooter at the start of the chain) can instruct automation down the chain is handy.

And I feel that AFD definatly has a place with any device that has a SDI interface for example.
Example: News shooter sets up a liveshot. It's 16:9, however it's not 4:3 safe. The SDI output of the camera feeds directly into the uplink encoder that then back at the studio gets fed into the video mixer. With miscommunication, the video mixer (/mixer operator(TD)) might accidentally center-cut the footage for a 4:3 output. If the camera set the AFD flag for "16:9 full frame" at it's SDI output, then video mixer would know to automatically letterbox.

Ok when the footage is ingested from the camera into a media archive, it would be handy to know how the footage was shot and how it should be presented if converted. Isn't this type of information the very idea of meta-data?


But Cameras aside .. how about other P2 gear .. like the HPG20? There's no reason that this couldn't be used as a deck to record a incoming program feed from a satellite (with AFD data embedded - as all NBC and FOX stuff is for example [Note that NBC and FOX have both adopted P2 as their house format.]) to then playback later. or process. or whatever..

Point beeing; in a mixed aspect ratio environment AFD is just as important part of the signal as closed captions, or color burst. Shouldn't the most flexible recording media on the planet be able to at least carry the signal?

- Mikko
 
If you think about it though- it could also really screw things up. Suppose a camera man sets the metadata incorrectly and suddenly a 16:9 clip is playing out to air as 4:3 with the sides chopped off. I'd imagine that only needs to happen once before the format is banned at a TV station as a shooting format. No one is going out directly to air from P2 any more than they're playing out DV tapes from a camera. I'm all for extended metadata going into post but in this case it seems like more potential for harm than help.

Noah
 
The same mistake could be made by accidentally shooting 4:3 and not 16:9 innitally. Or in the wrong codec, etc..
The HPX300 for example shoots in, what, 142 different image formats? You've allready got to know what you are shooting.

The AFD insertation could (should) be only an option if it was there in a camera. But in a "P2 deck" for example, it should be available to be recorded.
AVCintra for example is touted as a "Master" format ... AFD is *definatly* a signal that belongs in a master format.

Why after producing a master in AVC-I onto a HPG20, should I then have to pass the signal through a $3000 unit and onto some *other* format for delivery?

- Mikko
 
Yeah but I could say that about a host of other features too- why doesn't my camera shoot out a Blu-ray when I'm done. :) Not saying AFD is a bad option to have just makes a bit more sense in post. But maybe some camera maker will take it up. Personally I'd love to see a unified camera codec that comes out ready to edit without any major ingest step require and tons of EXIF-style metadata that's universal across all cameras.

Noah
 
But there's my point; I'm not talking about just (or necesarraly at all!) about cameras. But rather the format as a whole and it's use specifically in decks.

- Mikko
 
Yeah I could see that but I think it would have to become really adopted at the industry-standard level everywhere first. There's tons of other metadata stuff in various broadcast signals that cameras/decks ignore too. I suspect it will remain a specialty encoder box thing if/until more folks request it.

Noah
 
But P2 is part of everywhere else. Since when has Panasonic been the last on board with industry trends?
And I'm asking. :)

It's not that speciality of a thing. Loads of broadcast processing gear supports AFD. In fact every NBC station (that's some 200+ stations) in the US is using AFD every single day. NBC has been using AFD internally for years now. Fox has it in their national network delivery chain too. There are over 20 major broadcast companies that are fully supporting AFD and rolling it out across their lines of products.


If P2 can do it (and that's my question here, simply can it carry it? [I don't have access to gear to test it, or I just would]) then great, if not; I'll have to find some other option.

- Mikko
 
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