Cagey:

lalittle:

I don't understand how this would save any bandwidth.  It's still 23.976 fps of material displayed every second, so isn't the actual amount of image data per second the same?

Bandwidth is a measure of how big the chunks of data are that you are moving.  The data rate is a measure how much data is being moved per unit of time.  The analogy of pipe diameter, pressure, and volumetric flow rate works well for this where the bandwidth is the pipe diameter, the volumetric flow rate is the data rate, and the pressure is the frequency (determines speed of flow).  With interlacing, the frame size is halved so a lower bandwidth is possible.  When it comes to video, cutting your bandwidth in half will greatly reduce your costs.

I'm guessing that the reason we aren't seeing any true 1080p support is that it would be much more expensive, and besides, PsF isn't such a bad compromise.  IMHO side-by-side, most people would preceive the PsF version to be of higher quality do to it having less flicker.

Keith

Based on what I've been reading, the point of creating PsF was not to save on bandwidth, but rather to continue to utilize existing equipment and media -- which were designed for an interlaced environment -- when working with progressive video.  In other words, to maintain compatibility with current processing standards and equipment.

The part of this that still confuses me is the end result.  When the specs say that "Playback" is 24 and 23.976 PsF, are we talking about the signal from the Aja box to the monitor?  If so, does this mean that the monitor "sees" a PsF signal?  How is a PsF signal displayed on a normal progressive monitor?  Since 24PsF is still 24 progressive frames per second, does the monitor put the fields back together and display them as progressive frames, or do we see some sort of interlaced field sequence?  Are there certain monitor requirements for using the Aja?

I still don't understand what the PsF output spec actually means for people working with a 1080 23.976P project in Avid and wanting to display it to a normal progressive monitor using the Aja.  Is it possible that this is essentially a non-issue?

Thanks,

Larry

lalittle:

Based on what I've been reading, the point of creating PsF was not to save on bandwidth, but rather to continue to utilize existing equipment and media

Then why not support both?  Surely they would if it were feasable, especially considering progressive's prevalance and rapid adoption.

lalittle:

How is a PsF signal displayed on a normal progressive monitor?

Just like how an interlaced signal is displayed on a progressive monitor. 

Keith

lalittle:

Since 24PsF is still 24 progressive frames per second, does the monitor put the fields back together and display them as progressive frames

Yes (as long as the monitor is a modern one, the Sony BVM-D tubes may actually have been displaying 48i).

lalittle:

I still don't understand what the PsF output spec actually means for people working with a 1080 23.976P project in Avid and wanting to display it to a normal progressive monitor using the Aja

Here's the thing:

1. You need to know what the output device is providing, P or PsF (and on which spigots). Same image, different signal.

2. You need to know what your monitor excepts (and over which spigots), P or PsF.

AFAIK, any monitor that supports HDSDI input, will support PsF. So if you use HDSDI out of the AJA into an HDSDI-equipped monitor, you should be good to go.

A lot of (consumer/prosumer type) monitors will NOT support PsF over HDMI. So if you use the AJA box's HDMI output and stick it into an HDMI-capable monitor, it is not guaranteed to work, as not all monitors will accept PsF over HDMI.

This is true for Nitris DX, and it seems to be just as true for the AJA Io Express when used with Avid MC. There's the difference with the MXO2 Mini, which allows for P rather than PsF, making it more compatible with consumer/prosumer HDMI displays.

Cagey:

lalittle:

Based on what I've been reading, the point of creating PsF was not to save on bandwidth, but rather to continue to utilize existing equipment and media

Then why not support both?  Surely they would if it were feasable, especially considering progressive's prevalance and rapid adoption.

Based on the specs at the Aja site, the Aja box actually DOES support both -- it's just with MC 5.5 that it only supports PsF.  I totally agree that it seems absolutely bizarre in today's world not to support true progressive on a product like this.

lalittle:

How is a PsF signal displayed on a normal progressive monitor?

Just like how an interlaced signal is displayed on a progressive monitor.

I'm not sure how to interpret that given that we're dealing with a very specific "type" of interlacing here.  I'm not convinced that consumer HDTV's will even recognize a PsF signal.

On normal consumer progressive monitors in the US (scanning at 60Hz), a 24 fps signal that has had 3:2 pulldown applied will go through an inverse telecine process to reconstruct the original frames.  These frames will then be displayed using a 3-2 frame sequence in order to display 24 frames at a 60Hz progressive scanning rate.  (Many TV's now offer much higher scanning rates, but only some of them offer the ability to use these rates without turning on the "smooth motion" - i.e. frame interpolation - processing.)

If you're correct and a similar situation happens with a PsF signal, then this would mean that the original 24 fps sequence will be reconstructed and displayed as progressive frames.  This in turn would mean that this is entire subject is a non-issue since you end up with the EXACT same sequence of frames being displayed on the monitor.

What I'm not clear on is if normal consumer progressive monitors using HDMI actually work this way -- i.e. are they really able to understand a PsF signal.  I've never actually seen a consumer HDTV state specs on this, so I have no idea what the situation is.

Larry

lalittle:

This in turn would mean that this is entire subject is a non-issue since you end up with the EXACT same sequence of frames being displayed on the monitor.

lalittle:

What I'm not clear on is if normal consumer progressive monitors using HDMI actually work this way -- i.e. are they really able to understand a PsF signal.

Like I said, most of those don't support PsF. They won't understand the signal. A few will, apparently. I think Michael Phillips from Avid wrote here (in a 3D topic) that in Burlington, Avid has a consumer 3DTV with HDMI that accepts PsF. They simply took an Avid system to the local electronics store and tried some devices until they found one that would eat PsF.

Whenever they DO accept and understand the PsF signal, these monitors will display the very same picture as if they were fed P.

Job ter Burg:

Like I said, most of those don't support PsF. They won't understand the signal. A few will, apparently. I think Michael Phillips from Avid wrote here (in a 3D topic) that in Burlington, Avid has a consumer 3DTV with HDMI that accepts PsF. They simply took an Avid system to the local electronics store and tried some devices until they found one that would eat PsF.

Whenever they DO accept and understand the PsF signal, these monitors will display the very same picture as if they were fed P.

I was just writing a response to your previous post, but you beat me to it with this post, which answered some of the questions I was writing, so I dumped that post.

It sounds like what I was thinking was generally correct -- i.e. that P and PsF, once displayed, are identical, and that the only question would be if the display could ingest the signal.

I was also going to point out that I've never seen specs on a consumer HDTV that listed PsF -- i.e. there was no indication one way or another if they could handle the signal or not.  Apparently, this is indeed a problem since Avid themselves had to just go to the store and test sets until they found one that worked.

It would be really nice if there was a list somewhere that revealed what consumer displays could handle a PsF signal.  This single issue will determine whether I go with the Aja or the Matrox, so I need to find out what my choices will be when it comes to the display.  If the choices are overly limited, I'll have to give up the capture capabilities and go with the Matrox.  I simply need to monitor 1080p 24 fps projects from Avid.

Thanks again,

Larry

Remember that many HD televisions will accept an interlaced "aka Psf signal" via a component or RGB connection, indeed that is how I feed my Panasonic TH50-PF11 (as I cannot afford Job's HDSDI card for this model.

This works perfectly with both  the component input and the Dsub VGA type connector on this model.

The problem seems to be that many screens need a non interlaced signal on the HDMI input.

NubusAvid:

Remember that many HD televisions will accept an interlaced "aka Psf signal" via a component or RGB connection, indeed that is how I feed my Panasonic TH50-PF11 (as I cannot afford Job's HDSDI card for this model.

This works perfectly with both  the component input and the Dsub VGA type connector on this model.

The problem seems to be that many screens need a non interlaced signal on the HDMI input.

That's good to note as a potential workaround.

I'd still like to use HDMI if possible, however, and we're still faced with the fact that there doesn't seem to be any way of knowing if any given monitor can handle a PsF signal on ANY inputs before purchasing it.

Thanks,

Larry

NubusAvid:

Remember that many HD televisions will accept an interlaced "aka Psf signal" via a component or RGB connection

OK, now things are becoming too confusing.

In the PAL world, you could use a 'normal' 50i signal over component from any 50i or 25p project. Not from a 24.00p project, though.

From 23.976p projects, you could theoretically output 59.98i. This is NOT the same as PsF, this is with 3:2 pulldown added. The display will need to be able to inverse pulldown and destill the original 23.976 frames.

I know the MXO2 Mini offers this option, so that, in a 23.976p project, you can set the video output to 59.98i, and connect over component video. Not sure if that works from a 24.00p project, though!

I am not at all sure that the AJA offers this 59.98i output feature on 23.976p/24.00p projects. The DX boxes - AFAIK - do NOT.

The 'classsic' way of playing back 24p - think Sony HDCAM and HDSDI monitors - is PsF. This is different from 24p-over-60i.

lalittle:

there doesn't seem to be any way of knowing if any given monitor can handle a PsF signal on ANY inputs before purchasing it

Sorry, if I was confusing things.

Just saying the Panasonic "pro" plasma series will work with 24 Psf (48i) signals via component in.

The Sony LCD I tried did not work at 24Psf but did at 25Psf.

I think the key is that the monitor supports a refresh rate as low as 48Hz.

Kind a makes you wonder what's so bad w/ Full Screen Playback, LOL! Hook it up to a DreamColor or use a cheaper monitor and calibrate it with a probe and choose Expand Luminance for broadcast levels.

I'm saying this a little tongue in cheek, but with a few tweaks, it seems like FSP could be made to be very usable.

Job ter Burg:

lalittle:

there doesn't seem to be any way of knowing if any given monitor can handle a PsF signal on ANY inputs before purchasing it

Go to a store? Ask for a demo unit?

We're talking about consumer electronics here, not pro monitors, which means a normal consumer electronics store.  If the manuals for these HDTV's don't even say if PsF is supported, then there is absolutely zero chance that anyone at store will know the answer to this.  As far as a demo unit goes, there is no such thing in the consumer electronics arena.  As you yourself noted, even Avid had to take a system to the store and test the sets to find one that worked with PsF.

Larry

FWIW I just bought a Sony Bravia KDL40EX400 40" LCD and it works perfectly with the Matrox Mini/Avid MC5.0.3 in a 1080 23.976p  project - via HDMI. It was $666.99 with tax at Best Buy (on sale). A steal.

ronn:

FWIW I just bought a Sony Bravia KDL40EX400 40" LCD and it works perfectly with the Matrox Mini/Avid MC5.0.3 in a 1080 23.976p  project - via HDMI. It was $666.99 with tax at Best Buy (on sale). A steal.

They key question here is: what output signal is your Matrox MXO2 Mini set to?

I was doing some on-site final tweaking of a 23.976/1080p project with the MXO2 Mini and my MBP last year, hooked up to a simple living room LCD TV that happened to be there. Worked as well, but the Mini was set to output 59.94i, and I hooked them up over component.