Supporting non-square pixels

[Mike]

To better conform to broadcast standards I will be introducing support for non-square pixels in VidBlaster Broadcast. Not exactly sure yet how I will add these to the menu (true PAL 720*576?), and if we should resample all displayed video to square pixels or just program & preview.

Any suggestions or other technical feedback about this topic is appreciated. Martin Kay has already offered to run conformity tests when this has been implemented.

[Edwardgriswold]

This would be a big + for me since I'm trying to selling in to locations such as schools and sports arenas that would like to broadcast on local networks. I always get hit with the questions about outputting to NTSC 720x480 non square. The more broadcast like this system becomes the better penetration we will have in this market.

[PeterHazenberg]

+1

Some additional info: http://lurkertech.com/lg/pixelaspect/

[zenvideo]

My suggestion was for a new set of global resolutions, with the Video menu split into square and non-square groups, to include some or all of the following:-

Webcasting (square pixel)
(all the existing resolutions)

Broadcast SD (non-square)
PAL 720x576 standard 4:3 (1.0940)
PAL 720x576 widescreen 16:9 (1.4587)
NTSC 720x480 DV standard 4:3 (0.9091)
NTSC 720x480 DV widescreen 16:9 (1.2121)
NTSC 720x486 standard 4:3 (0.9091)
NTSC 720x486 widescreen 16:9 (1.2121)

[Mike]

Thanks. 720p and 1080p are also used in broadcasting so I think this can be confusing.

[PeterHazenberg]

Thanks. 720p and 1080p are also used in broadcasting so I think this can be confusing.

I agree. This square / non-square issue is only related to SD environments. From HD on only square pixels are used. Without denying the world of SD, I think professional/broadcast is mainly square pixel anyway...

[zenvideo]

Thanks. 720p and 1080p are also used in broadcasting so I think this can be confusing.

Although they are HD, not SD. That's why I used the term "Broadcast SD", but perhaps "Legacy SD" might be better if you wish to convey a sense of obsolescence to the whole issue of non-square pixel usage. Production of DVDs with their quaint non-square pixels should be ending any day soon, I hear.... http://forum.vidblaster.com/images/smilies/smiley.gif

[Mike]

Thanks all. I added two new resolutions to the menu of v2.10:

720*480 (SD NTSC NSP)
720*576 (SD PAL NSP)

Used NSP to indicate non square pixel as I could not find a better description and adding the PAR makes no sense if the resolution does not change. As no one mentioned anything about display I will assume for now you do not want any adjustment for the PAR in the displays. This was confirmed by someone who mentioned doing this to save CPU usage. Obviously this means distortion of displayed video so I will document this in the help.
I also decided to make this available to all editions, for now anyway, as above posts made clear this is not really a broadcast matter anyway.

[zenvideo]

Thanks all. I added two new resolutions to the menu of v2.10:

720*480 (SD NTSC NSP)
720*576 (SD PAL NSP)

Well, it's certainly a step in the right direction and will save those of us who have had to resort to editing the .ini file the trouble of doing so.

I look forward to trying it, because as things stand I can't tell whether you've done anything beyond putting a global "720*x" SD resolution into the menu.

Used NSP to indicate non square pixel as I could not find a better description and adding the PAR makes no sense if the resolution does not change. As no one mentioned anything about display I will assume for now you do not want any adjustment for the PAR in the displays. This was confirmed by someone who mentioned doing this to save CPU usage. Obviously this means distortion of displayed video so I will document this in the help.
I also decided to make this available to all editions, for now anyway, as above posts made clear this is not really a broadcast matter anyway.

Surely anyone dealing with 16:9 display-ratio video would prefer to see it displayed as such, and not as something closer to 4:3? That's why I suggested the two versioins earlier in the thread:-
PAL 720x576 standard 4:3 (1.0940)
PAL 720x576 widescreen 16:9 (1.4587)

The two versions would use different display ratios whilst keeping the underlying frame data at the same pixel size, as already happens in the real world of broadcast video. OK, maybe I didn't spell this out in the previous post but I certainly meant it (with reference to "...no one mentioned...").

You could drop the pixel aspect ratios if you don't think they'll mean anything to people, or maybe:-
PAL 720x576 standard 4:3 (NSP)
PAL 720x576 widescreen 16:9 (NSP)

However, I for one am a little puzzled by the term "NSP" in the menu as it's not something I'm used to seeing in that sort of context. And I don't think broadcast users would be fazed by seeing PAR values in a menu, given that most good editing & encoding software includes them, which they might already be familiar with. And the whole reason for quoting actual PAR values for SD video is BECAUSE the underlying resolution doesn't change, so you need to know (in the case of PAL) what your 720x576 pixels is supposed to represent when it's displayed.

Anyway, maybe something for the future...

[Monoscopio]

Would it also be possible to set the 16:9 flag in the video output module to let tv-sets, dvd-recorders etc. automatically recognize that its widescreen?

[Mike]

Sigh. Thanks for the feedback. I clearly asked this and no one replied, so I took what I read elsewhere on the forum (keep 1:1 all the way to save CPU).

I removed this from the software and the help again and will wait for further discussions about what is preferred.

This will not be implemented in v2.10.

[zenvideo]

Sigh. Thanks for the feedback. I clearly asked this and no one replied, so I took what I read elsewhere on the forum (keep 1:1 all the way to save CPU).

I removed this from the software and the help again and will wait for further discussions about what is preferred.

This will not be implemented in v2.10.

The trouble is, we all want everything, and there's only one of you! :) I do feel for you in this position with so many different requests coming in.

I stand by what I wrote at the begining, today, that this would have been a good and welcome step, even if it didn't go as far as I would have liked. I think it would have been better to move forward on this, even by a small step, than do nothing at all. As I said at the end of my post, the rest can came later...

[Dave Owen]

Personally I couldn't care less about non-square pixels and I'd prefer that Mike's efforts were looking towards the future than the past, but FWIW I feel showing the PAR would be more useful than "NSP". PAR is more in line with editing software, it's something that video producers who care about aspect ratio should already be familiar with, and it provides more information. Just my 5 cents on a relatively insignificant matter, but there ya go.

[Niko]

For our use the non-square 720x576 would be a really welcome option. I understand that it may not be important for those working in HD, but my view is that it really is the only way to do standard-definition video (PAL or NTSC) right. Especially when you consider our current workflow, which is:

1. Capture and mix from FireWire DV PAL sources (720x576)
2. Vidblaster converts this to 1024x576
3. We edit the final result in Avid Media Composer (converted back to 720x576)

This causes unwanted aliasing and moiré effects. Having the 720x576 option would really solve a lot of problems for us. I believe we could get much closer to the quality of the original 720x576 DV sources that way (which are 3CCD Sony HVR-Z7 cameras).

I would definitely welcome this option - even without pixel aspect ratio correction. However, having the possibility to enable pixel aspect ratio correction (perhaps even for individual modules) would help a lot. Especially as I believe most of us are currently using 16:9 which looks quite weird in 720x576 square pixels, which has 5:4 aspect ratio.

[Niko]

Any news on this feature? Having 720x576, even without pixel aspect ratio correction, would result in much better quality from professional SD video sources.

[ClementN]

We use PAL 720x576 widescreen 16:9 (1.4587) .

Having that supported in VB will be a big plus !!

[ivan gonzalez]

any news on non square pixel for dv 720x480?