Steve, simply with VLC streaming from Capture Device (uses DirecDraw). NO line twitter - just like with captured files. Now, what do you make out of this?!!

The i.LINK should be getting an exact copy of the bits on tape. Assuming you are using VLC with deinterlace DISABLED -- that would mean the 2 fields are going into 1 frame that is repeated twice per second. This is the correct way of presenting 25p.

So what's happening with the camera analog & HDMI output?

I assume it's sending out one field then the next field. Each field has only 540-lines. It is an interlaced signal which means a monitor will treat it as interlaced. Static video will have it's fields woven together (weave) into a frame and presented twice per second. No twitter.

What happens with motion video is based on the monitor's deinterlacer. It might bob, or do something much better.

If bob: the first field's odd lines go into a 1080-line frame. The 540 missing (even) lines are interpolated from the existing 540-lines. Now this frame is presented for 1/50th second.

Then, the second field's even lines go into a 1080-line frame. The 540 missing (odd) lines are interpolated from the existing 540-lines. Now this frame is presented for 1/50th second.

Herein lies the problem. Watch the top odd line: it goes from real to interpolated to real to interpolated.

A thin line will fall on a single row. Assume the line falls on top of real line. The next interpolated line CANNOT have this thin line. So when you watch, every 1/50th of a second it dissappears. On and off. On and off.

bob generates flicker. Hence the name bob.

I'll bet if you plug the V1 into an HDTV that does not do bob the twitter will go away. There are two levels of Bravia. One is a cheap unit typically sold in Asia, etc. The S2 if I remember.

Look for an XBR HDTV.

I think the reason we see this only on the E/P is because the CMOS sampling rate is higher than it is for the U -- yet the chips have the same number of rows. This causes more aliasing, but also captures more V rez. hence the E/P actually records finer vertical detail. Hence, the greater possibility of very "thin" lines.

If I'm correct, it is an unhappy combination of the V1's geater V. rez. plus its interlaced PsF plus a bob monitor's deinterlacer. A real bad combination.

Can anyone guess why the E/P might have a CMOS sampling rate is higher than it is for the U?

As I pointed out before, here's the problem. Vegas cannot print to tape 25PsF the same as the camera records. That's straight from the Vegas engineers. Also there's no way to PTT 25p as per Canon either.

So Vegas is a one way solution. That would be like editing 24p from the DVX100 and never being able to record 24p back to the camcorder.

Now I wonder if it also cannot record 30p and 24p back to the V1U.

Spot?

So Vegas is a one way solution. That would be like editing 24p from the DVX100 and never being able to record 24p back to the camcorder.

Now I wonder if it also cannot record 30p and 24p back to the V1U.

Spot?

Yes, from the timeline you can only print a 1080/50(60)i back to tape, but as I mentioned earlier you can print a 25p file from your HDD as well.

Steve, what would your "bottom line" verdict on the V1E's 25PsF be, based on what we established? Your theory on why the line twitter appears (and spoils the picture) under certain conditions boil down to how the video is watched and NOT to how it's produced - do I get you right?

Look for an XBR HDTV.


Steve, I cannot find XBR in the context of European Bravia models, and the local dealer never heard of it. Any hints?

but as I mentioned earlier you can print a 25p file from your HDD as well.
How do you write a 25p file from your HDD using Vegas to the V1?

Later today I'm going to burn your 25p and play it on my hd dvd play. This would be like your using a 50i movie.

lets see if the twitter stays gone.

I'm heading to bed.

Sorry Steve, my bad. Yes you can pick a progressive movie file from your HDD and print it to tape from within Vegas, but it is recorded in the interlaced format anyway.

So Vegas is a one way solution. That would be like editing 24p from the DVX100 and never being able to record 24p back to the camcorder.

Now I wonder if it also cannot record 30p and 24p back to the V1U.

Spot?

No 30PsF back to tape either, only 24p. Keep in mind though that as far as I'm aware there's no way to send a frame down component.
One can pretty easily convert 25p to 24p in Vegas without any resampling, you can do a precise frame rate conversion. There's at least one utility to do this in FCP too.

As to are the bit clocks faster in the V1E.
I'd suspect they might be. In SD DV they're the same 13.5MHz, the lower PAL frame rate yields more pixels in the same bps. What happens in HD where there's the same number of pixels and a different frame rate?
My best guess is the bitclock runs faster and hence yields more res.

The i.LINK should be getting an exact copy of the bits on tape. Assuming you are using VLC with deinterlace DISABLED -- that would mean the 2 fields are going into 1 frame that is repeated twice per second. This is the correct way of presenting 25p.

So what's happening with the camera analog & HDMI output?

I assume it's sending out one field then the next field. Each field has only 540-lines. It is an interlaced signal which means a monitor will treat it as interlaced. Static video will have it's fields woven together (weave) into a frame and presented twice per second. No twitter.

What happens with motion video is based on the monitor's deinterlacer. It might bob, or do something much better.

If bob: the first field's odd lines go into a 1080-line frame. The 540 missing (even) lines are interpolated from the existing 540-lines. Now this frame is presented for 1/50th second.

Then, the second field's even lines go into a 1080-line frame. The 540 missing (odd) lines are interpolated from the existing 540-lines. Now this frame is presented for 1/50th second.

Herein lies the problem. Watch the top odd line: it goes from real to interpolated to real to interpolated.

A thin line will fall on a single row. Assume the line falls on top of real line. The next interpolated line CANNOT have this thin line. So when you watch, every 1/50th of a second it dissappears. On and off. On and off.

bob generates flicker. Hence the name bob.

I'll bet if you plug the V1 into an HDTV that does not do bob the twitter will go away. There are two levels of Bravia. One is a cheap unit typically sold in Asia, etc. The S2 if I remember.

Look for an XBR HDTV.

I think the reason we see this only on the E/P is because the CMOS sampling rate is higher than it is for the U -- yet the chips have the same number of rows. This causes more aliasing, but also captures more V rez. hence the E/P actually records finer vertical detail. Hence, the greater possibility of very "thin" lines.

If I'm correct, it is an unhappy combination of the V1's geater V. rez. plus its interlaced PsF plus a bob monitor's deinterlacer. A real bad combination.

Can anyone guess why the E/P might have a CMOS sampling rate is higher than it is for the U?

Your assumption about static video at least on the Barvia V series would seem incorrect unfortunately. With the V1P connected HDMI to the display and a locked down camera with nothing moving in the frame it most certainly can twitter.

Thanks for your explaination of how bob works, from what I've seen on the Bravia it looks exactly like what you'd get if that's what it's doing, as you've rightly said it shouldn't be doing that, it should be weaving.

Is this just a sloppy display device or is it something the camera is sending it fooling it into bobbing when it should be weaving?

I need to go back and very carefully recheck this but I'm 80% certain that my 25p footage shot at 1/25th on a bright sunny day shows no twitter on the Bravia. With the camera connected directly via HDMI to the Bravia and pointed into our flat well lit office, no line twitter in 25p. Move the camera around to point at a dimly lit page with fine horizontal lines, twitter.

How is the display being fooled, my best guess, noise.
I should check this by simply pointing the camera at the same problematic subject and changing the light level while letting the camera raise gain.

I need to go back and very carefully recheck this but I'm 80% certain that my 25p footage shot at 1/25th on a bright sunny day shows no twitter on the Bravia. With the camera connected directly via HDMI to the Bravia and pointed into our flat well lit office, no line twitter in 25p. Move the camera around to point at a dimly lit page with fine horizontal lines, twitter.

How is the display being fooled, my best guess, noise.
I should check this by simply pointing the camera at the same problematic subject and changing the light level while letting the camera raise gain.

I'm afraid I cannot confirm this observation Bob. When on HDMI or Component, the line twitter is present on ALL contrasty, nearly horizontal lines - also in those picture areas where there is virtually no noise at all.

I'm afraid I cannot confirm this observation Bob. When on HDMI or Component, the line twitter is present on ALL contrasty, nearly horizontal lines - also in those picture areas where there is virtually no noise at all.


Thanks for that.
I'll still do the tests later this week.
On this very matter though here's what has me confused.

With a locked off shot, no camera or subject motion. What the camera is sending to the Bravia will be the same whether the camera is in I or P, two fields with no temporal offset. Now Steve has said the resolution is the same in I or P, OK. So why does the Bravia not display any twitter in I and yet it does in P?

In theory in I a camera is supposed to employ line averaging to avoid twitter but from what Steve was saying some time ago, this camera doesn't do that. I'm not so certain this is correct. The noise levels are lower in I and the twitter is missing from the display.

The noise levels are lower in I and the twitter is missing from the display.

Confirmed here 100%, but the twitter aside, the noise in 25p I can live with as the price for the ultra-sharp picture I'm getting with sharpness levels up to 12 (I didn't test higher). And there are many situations (depending on contents etc) where sharpness of 4 or 5 is enough, and the noise (dancing pixels) are negligible then.

If we could nail down the true nature of the line twitter and devise an optimal method of delivering 25p without it, I'm sold on the V1E.

Your assumption about static video at least on the Barvia V series would seem incorrect unfortunately. With the V1P connected HDMI to the display and a locked down camera with nothing moving in the frame it most certainly can twitter.


Is this just a sloppy display device or is it something the camera is sending it fooling it into bobbing when it should be weaving?

How is the display being fooled, my best guess, noise.
I should check this by simply pointing the camera at the same problematic subject and changing the light level while letting the camera raise gain.

I think you are onto something here. Besides twitter, I find that as S is increased the whole picture gets "busy" on fine details. This dancing dot noise is aliasing. So is the barber pole banding you see on thin objects. All this is "noise" heading toward the display.

So it could be that even on static VIDEO, the changing noise accross fields is enough to trigger the deinterlacer into not weaving.


"Steve was saying some time ago, this camera doesn't do that ..."

I've worried about this. Last night I rechecked the stuff from Japan. The cmos signals pass through a signal-procesing chip on the way to the eip. I now think that in interlace mode a flicker filter is engaged which will also slightly reduce noise. This confirms your finding.

Later I'll burn my hd dvd and see what happens when it feeds the signal to the hdtv.

Thanks for that.

In theory in I a camera is supposed to employ line averaging to avoid twitter but from what Steve was saying some time ago, this camera doesn't do that. I'm not so certain this is correct. The noise levels are lower in I and the twitter is missing from the display.

Bob, as mentioned in my post a while back (twitter being different than...etc)
it was mentioned that the V1 does indeed have a set level average to avoid twitter. Sony confirmed the feature a while back.

Bob, as mentioned in my post a while back (twitter being different than...etc)
it was mentioned that the V1 does indeed have a set level average to avoid twitter. Sony confirmed the feature a while back.

I wonder why Sony hasn't adjusted the settings for the E/P. Turning down Sharpness is a brute force solution as it kills both H. rez. (bad, and totally unneeded) as well as V. rez. (ok, but not ideal).

A flicker filter is a much more precise way of handling flicker.

Bob, as mentioned in my post a while back (twitter being different than...etc)
it was mentioned that the V1 does indeed have a set level average to avoid twitter. Sony confirmed the feature a while back.

Must admit I'd missed that one, thanks.

I wonder why Sony hasn't adjusted the settings for the E/P. Turning down Sharpness is a brute force solution as it kills both H. rez. (bad, and totally unneeded) as well as V. rez. (ok, but not ideal).

A flicker filter is a much more precise way of handling flicker.


There's a flicker switch but I thought it was for shooting 50Hz in a 60Hz country or vice versa, same as the Z1.

There's a flicker switch but I thought it was for shooting 50Hz in a 60Hz country or vice versa, same as the Z1.

You are correct -- the switch is for the 50Hz / 60Hz.

Not "our" twitter.

There's a flicker switch but I thought it was for shooting 50Hz in a 60Hz country or vice versa, same as the Z1.

You're correct, Bob. The flicker switch has no bearing on what this thread is discussing.

Good news. The 25p timeline that I exported as 1080/60i through compressor did play -- with some dropped frames -- on my HD DVD player.

Four 25p S=8 clips:

1) no flicker filter: bad flicker -- just like original

2) minimum flicker filter -- less flicker

3) medium flicker filter -- even less flicker

4) maximum flicker filter -- very very little flicker

Looking at these results it seem with FCP it is possible to clean the signal such that when played from an hd dvd player to my HDTV -- it looks good. And, unlike the S=3, the bark on the tree is very detailed.

Sony's S=3 recommendation does not show a lot of research. It seems a panic fix.

However, I think S=8 is just too high. I think S=5 or S=6 would provide more than enough detail and enable the filter to remove all of it.

In fact, for a film look, the image needs to be a bit softer. If not 5, no more than 6.

I'm also wondering if I had made a 1080/50i disc -- would my Toshiba play it. And, would my HDTV show it. I'm wondering how multi-system these units might be.

So if you upload an S=5 clip I'll try it.

Anyway, I think it's clear there is an HD production solution for 25p.

Piotr, for all the work you've done, Sony should give you a V1. Thank you for all your help.

Steve, thank you very much for your work! I'll upload an S=5 clip later today. It may sound dumb, but do I get it right you've engaged a flicker filter in FCP? Is the "Reduce interlace flicker" its counterpart in Vegas?

Steve, thank you vey much for your work! I'll upload an S=5 clip later today. It may sound dumb, but do I get it right you've engaged a flicker filter in FCP? Is the "Reduce interlace flicker" its counterpart in Vegas?
Yes -- and the FCP filter has the levels. With S=8 it required the Max level to eliminate most of the twitter.

I also tried to make a 50i hd dvd. Compressor will not let me -- no 50i support. When I get your new clip, I'll try a 25p. However, I suspect that the burning software may reject it.

Right now I'm going to see if the burning software will work with 24p. I fear not.

Steve, the weather today is too dull for comparative shooting; I do have ready S=5 clips on disk but the shortest is just above the 100 MB limit of the server I've been using. Can you suggest any other host for a 107 MB file - if so, I could upload it immediately? Can your e-mail server accept an over 100 MB file?

Of course I can trim it, but this would require recompression...

Steve,
Which HD-DVD model are you using? Does it have 1080p output?

OK, so here is the link to a raw clip with sharpness=5:

http://rapidshare.com/files/19694265/s_5.m2t

I also encoded it using Vegas Flicker Reduction switch; please compare it with your FCP flicker switch and assess which of its levels it is closest to.

Here is the link: http://rapidshare.com/files/19712604/s_5_with_flicker_filter_Vegas.m2t

Finally, I encoded it again using the smallest possible amount of the Gaussian Blurr (V=0.001), and this - while showing noticeable softening of the image - eliminates all twitter, even with VLC bobbing, which we have esablished as most closely mimicking the "live" ipnut from camera.

Here is the link: http://rapidshare.com/files/19727858/s_5_with_Gaussian_Blur_V_0.001_in_Vegas.m2t

My opinion is that - with 25PsF playing fine with sharpness up to 12, provided no deinterlacing kicks in - we should try to find a way to deliver it that way, rather than reduce the resolution (even if vertical only). Sony should definitely speak their standpoint on this.

.


My opinion is that - with 25PsF playing fine with sharpness up to 12, provided no deinterlacing kicks in - we should try to find a way to deliver it that way, rather than reduce the resolution (even if vertical only). Sony should definitely speak their standpoint on this.

Piotr,
from my work with this issue in SD there simply is no way to deliver 50i (or 60i I'd have to suppose) with V res greater than half the number of lines. Barry Green makes much of this in his support for progressive scan but I think the point missed is that even if you've acquired in P there's no way to force display devices to display it properly. SD CRT TVs only do I and I can assure you flicker can be a huge problem if you don't carefully watch what you're doing. HD CRT displays will do exactly the same thing. LCD displays that attempt to emulate interlace display will also manage to create flicker.

Someone correct me if I'm wrong but this 'bob' display system is close to what a real interlace display does. The difference would seem to be that bob will cause the edges to appear to roll or bob, a proper interlaced display will make them blink.

A fine line only one scan line high is always going to flicker on a 50i display. When the CRT writes that line, it's only displayed for as long as the phosphor persistance lasts. It's another 40mS before it gets displayed again. Something blinking at 25Hz is well under the point where persistance of vision kicks in, it's more of a problem where the duty cycle is very low, that's why the problem is worse on CRTs than LCDs, the poor response times of LCDs helps but as you've seen it's still not enough to totally avoid the problem. R60 displays will do a little better but still not good enough to eliminate the problem.

The only correct way to display 25p is what is effectively 50p, merge the fields and display the same frame twice. This is almost the same as what a film projector does with a two blade shutter.

None of this is really the cameras fault, it's delivering a perfectly good 25p image, you might argue it's too good but I'd rather have the res in the first place, it's going to make many things easier in post. The down side is you need to factor in at some point having to reduce the V res depending on your delivery.

Steve,
Which HD-DVD model are you using? Does it have 1080p output?

I have the A2 which only has 60i. This is no problem for me because I bought it only for my own work which, except for what I shot is Asia as a test, will always be 720p or 1080i60.

"Barry Green makes much of this in his support for progressive scan but I think the point missed is that even if you've acquired in P there's no way to force display devices to display it properly."

With 720p60 the monitor simply skips the deinterlacer and shows the P video exactly as it came from the CCDs. It looks perfect. I've used 720p since day 1 of HDV and I've never had a problem.

The fact is CineAlta is an acquistion format and I perhaps all PsF formats should be used that way. Or, at least that's true for R50 V1 video. The R50 V1 has way too much V. rez and too much aliasing in P mode. There really is a "problem" with the V1E/P. Turning S to 3 is a very bad fix for real production work. Euro Sony should get on top of this with a White Paper.

I have the A2 which only has 60i. This is no problem for me because I bought it only for my own work which, except for what I shot is Asia as a test, will always be 720p or 1080i60.

"Barry Green makes much of this in his support for progressive scan but I think the point missed is that even if you've acquired in P there's no way to force display devices to display it properly."

With 720p60 the monitor simply skips the deinterlacer and shows the P video exactly as it came from the CCDs. It looks perfect. I've used 720p since day 1 of HDV and I've never had a problem.

The fact is CineAlta is an acquistion format and I perhaps all PsF formats should be used that way. Or, at least that's true for R50 V1 video. The R50 V1 has way too much V. rez and too much aliasing in P mode. There really is a "problem" with the V1E/P. Turning S to 3 is a very bad fix for real production work. Euro Sony should get on top of this with a White Paper.

"The V1E/P has too much V res."

Maybe, depends how you want to deliver it and / or do with it. Wouldn't as much V res as possible be better for keying, display from computer systems or a film out?

Has anyone put a V1U and V1E upto a res chart to compare them?
Also lets not forget the V1U in 30p, is it having the same issues?

And we can still shoot 25p to deliver 24p very easily. Is even 24p guaranteed to be displayed correctly anyway. I realise you've got more of a shot with it than anything else but I'm under the impression it can still be problematic.

Regarding 720p, I don't think it's a big enough step up from SD in R50 countries to hold much attraction some how. That might be wrong in some ways based on what we're seeing, if 720p always gets displayed correctly then effectively the usable V res is about the same as 1080, if not higher.

"The V1E/P has too much V res."

Wouldn't as much V res as possible be better for keying, display from computer systems or a film out?

Has anyone put a V1U and V1E upto a res chart to compare them?

And we can still shoot 25p to deliver 24p very easily. Is even 24p guaranteed to be displayed correctly anyway.

if 720p always gets displayed correctly then effectively the usable V res is about the same as 1080, if not higher.

No problem with 30p or 24p so that's why I said it is only the R50 V1. While we have been focused on twitter, the other reason Sony recommended S=3 is to minimize aliasing. Same reason I use S=5/6 even though I don't have twitter. I would still not use above S=5/6 for the V1E/P.

720p always gets displayed correctly on progressive displays. That's why I'm such a fan of P. The V1 res is only VERY slightly higher than JVC 720p. So there is no real loss going to 720p. Tests have shown P "looks" 1.5X more detailed than I. So until there is 1080p, 720p is a far better format.

However, to get to 720p one has to convert files. If one is going to do this then there are two other options:

1) DVCPRO HD at 1080i50 which is 1280x1080 at 4:2:2 at 10-bits. This is a great option as it preserves full V. rez and 1280 is more than enough H. rez for a camcorder with only 960-pixels. You can export from Compressor for HD DVD at 1080p25. I'll soon know if it can be burned.

2) CineForm's new codec gives you 10-bits.

You can also convert to 720p25 AIC. This file is 317MB for 30S vs 422MB for DVCPROHD. I would go with DVCPROHD. However, it may be reduction to 720p may reduce V. rez automatically eliminating the need for a Flicker Filter.

-------------------

If the flags are set properly and one has a hidef dvd player that outputs 1080p60 -- then 24p will be perfect. The real goal in the USA is now 1080p24 into an LCD that will display it at 24p or 48p. This will duplicate a movie perfectly.

How are you easily going to get 25p to 24p without audio problems?

How are you easily going to get 25p to 24p without audio problems?

Too many ways to count on two hands. Without any hardware, just open a 25p file in Vegas. Set project properties to 24p, drag audio. No sync issues, regardless of the length of the project. There is always Minerva, there are also resampling algorithms in most DVD player decoders that account for this.
24p to 25p, 25p to 24p, 24p to 60i, 60i to 25p, 30p to 24p, 24p to 50i...none of these framerates offer challenges any longer on the audio side, even if they do present difficulties to some degree on the video side.

I'd bet Bob does this in his sleep, given the work he does.

How are you easily going to get 25p to 24p without audio problems?

Ctl+Drag the end of the event so it's 4% longer, you've got the option of correcting the 4% pitch change in the audio. Pretty much the reverse of what our telecines do except I'm told they don't even bother to shift the audio pitch back.

The question of how to do this in FCP came up on the Sony Vegas forum, from memory there's 3rd party utilities to do the same thing.

Probably the safest approach so you don't have a can of worms is to convert as a final step i.e. run a 25p project, render a mixed master and convert that.

Ctl+Drag the end of the event so it's 4% longer, you've got the option of correcting the 4% pitch change in the audio.

The question of how to do this in FCP came up on the Sony Vegas forum, from memory there's 3rd party utilities to do the same thing.

"Without any hardware, just open a 25p file in Vegas. Set project properties to 24p. No sync issues, regardless of the length of the project."

Bob, are you talking about Vegas? If so, Spot's solution seems the easier way. Of course, I wasn't really asking about Vegas -- because with Vegas unable to record 25PsF back to HDV, it isn't an NLE I would recommend for R50 users who want to shoot 25p.

I was hoping there were some FCP or Premiere lurkers in R50 areas. Somebody is reading all these posts. :)

I was hoping there were some FCP or Premiere lurkers in R50 areas. Somebody is reading all these posts. :) I am but I can't make head nor tail of any of it. Just when I think I've got this technology figured out they tell me otherwise.

Someone wrote to me that editing V1 footage shot in 25p mode in a 50i project in PPro (without AspectHD) resulted in pure 25p output. But I've read otherwise since. I don't understand a thing...

"Without any hardware, just open a 25p file in Vegas. Set project properties to 24p. No sync issues, regardless of the length of the project."

Bob, are you talking about Vegas? If so, Spot's solution seems the easier way. Of course, I wasn't really asking about Vegas -- because with Vegas unable to record 25PsF back to HDV, it isn't an NLE I would recommend for R50 users who want to shoot 25p.

I was hoping there were some FCP or Premiere lurkers in R50 areas. Somebody is reading all these posts. :)

What difference will it make if you can or cannot record 25PsF back to tape?
If you record it back as 50i or 25PsF what comes out the HD component from your deck is exactly the same isn't it?
If you capture it back all you have to do is tell your NLE it's Progressive, hardly a difficult task, certainly not with Vegas and I'd guess with most other NLEs as well, after all we've been getting telecined film that way since day one in R50 land. I'd hazard a guess most people just process it as 50i, the only downside being any temporal FXs will come out truly interlaced, it's indeed better to tell the NLE to keep everything progressive.
You'll face the exactly same issues with 25F once it's captured for that matter.
Personally I wouldn't recommend going back to HDV anyway, one pass of HDV compression is bad enough.

Does any of you guys have access to an HDTV with FireWire input? Since feeding 25PsF live (before or after tape) into VCL using i.link doesn't create twitter, it'd be an interesting test!

As a side note: does any of the current, early HD/Blu-Ray DVD players have i.link outputs?

I am but I can't make head nor tail of any of it. Just when I think I've got this technology figured out they tell me otherwise.

Someone wrote to me that editing V1 footage shot in 25p mode in a 50i project in PPro (without AspectHD) resulted in pure 25p output. But I've read otherwise since. I don't understand a thing...

I am not surprised you finding it hard to follow.

If I have followed the meanderings correctly there is an inference that because the V1E is not sending a progressive flag via hdmi that HD DVD and Blu-ray players will not do it either.

There seems to be a misunderstanding of the Blu-ray specs. 25P will be supported via 50i. 25P is not listed in the specs as 25PsF is 50i and the only true progressive mode that is supported is 24P. That really is progressive encoded material and will be supported across all regions. In PAL land we'll watch BD at normal speed at last.

So how will TVs know not to deinterlace 25PsF? There are two methods, cadence detection and flags.

I am 99% certain of the facts but I have emailed a friend who is a very skilled DVD author using Scenarist. I am hoping he has some detailed knowledge of BD and will confirm what I say and give a greater insight.

TT

There seems to be a misunderstanding of the Blu-ray specs. 25P will be supported via 50i. 25P is not listed in the specs as 25PsF is 50i and the only true progressive mode that is supported is 24P. That really is progressive encoded material and will be supported across all regions. In PAL land we'll watch BD at normal speed at last.

So how will TVs know not to deinterlace 25PsF? There are two methods, cadence detection and flags.

I am 99% certain of the facts but I have emailed a friend who is a very skilled DVD author using Scenarist. I am hoping he has some detailed knowledge of BD and will confirm what I say and give a greater insight.

TT

Tony, this is a very interesting and promising assumption. Please let us know what your friend has to say! BTW, do you think that the 25F from Canon doesn't show twitter because it is correctly recognized and not de-interlaced by HDTVs, or because it has less overall aliasing (at least at the default sharpness settings, as I didn't test it with sharpness turned up)?

Tony, this is a very interesting and promising assumption. Please let us know what your friend has to say! BTW, do you think that the 25F from Canon doesn't show twitter because it is correctly recognized and not de-interlaced by HDTVs, or because it has less overall aliasing (at least at the default sharpness settings, as I didn't test it with sharpness turned up)?


If you can trust the figures from the Texas shootout the XL-H1 reads 540 lines vertical res. I doubt the Canon A1 is any higher. This would probably explain why the Canon doesn't have the same issue. I think Steve was saying the V1 reads 700+

I've just tried converting 25p to 24p using Vegas. I'm doing it the long way as this avoids any interpolation. It is covered quite well in the documantation. In brief you measure the number of frames using the ruler at 25p, change the project to 24p, move the cursor to the original frame number and ctl-Drag the end of the clip to the cursor. You've slowed down the clip as needed, no different to changing the speed on a projector.

The 24p looks every bit as good as the 25p on the Vegas preview monitor. Except I'm having no end of fun trying to render it to anything without it falling to bits on fast motion. It looks like pulldown is being added but I'm compressing frames instead of fields, the macroblocking is really bad. Need to do more research on this.

What difference will it make if you can or cannot record 25PsF back to tape?
If you record it back as 50i or 25PsF what comes out the HD component from your deck is exactly the same isn't it?

Personally I wouldn't recommend going back to HDV anyway, one pass of HDV compression is bad enough.

Obviously one can NOT record 25p or 30p to a V1. And, I assume Piotr knows that as well. He, if I remember correctly, said he could not record a 25p TIMELINE because Vegas would not convert it to the 50i needed for recording.

There is no such thing as "HDV" compression. HDV is only the marketing name attached to one Profile/Level of MPEG-2 encoding. There is little difference between the MPEG-2 recorded to HD DVD or BD and the MPEG-2 HDV recorded back to tape.

So if you fear re-encoding to HDV you equally will fear encoding for an HD DVD or BD disc.

Same "stuff" in both cases. That's why you can take an HDV file and make an HD DVD without any re-encoding.

For the next few years it will be a lot smarter to carry an HDV camcorder and your production's tape than it will be to assume you'll find an HD DVD player waiting for you in Asia or Europe -- or even the USA.

If you can trust the figures from the Texas shootout the XL-H1 reads 540 lines vertical res. I doubt the Canon A1 is any higher. This would probably explain why the Canon doesn't have the same issue. I think Steve was saying the V1 reads 700+

I was sent a chart. When I look at the chart -- I see lots of aliasing at 800. So I'm being more conservative when I say 700+. Horizontally it was a solid 800 -- the same as the Canon.

The shootout had an F9xx at 1000x1000 -- so the V1 really does well. In fact, if not scaled/filtered to 1440, the 3ClearVid system might offer 1000 horizontally. And, Sony just happens to have a 24Mbps version of AVCHD that records 1920x1080.

So just when we've bought all our HDV toys ...

If
The 24p looks every bit as good as the 25p on the Vegas preview monitor. Except I'm having no end of fun trying to render it to anything without it falling to bits on fast motion. It looks like pulldown is being added but I'm compressing frames instead of fields, the macroblocking is really bad. Need to do more research on this.

Same here Bob - everything looks perfect but any motion!
However, when I deliberately BOB the 24p output in VLC, and send it to my LCD via component - the twitter is still there. Probably my monitor doesn't recognize it properly, either. Of course I'm bobbing it just out of curiosity, as 24p definitely shouldn't use ANY de-interlacing.

Does any of you guys have access to an HDTV with FireWire input? Since feeding 25PsF live (before or after tape) into VCL using i.link doesn't create twitter, it'd be an interesting test!

As a side note: does any of the current, early HD/Blu-Ray DVD players have i.link outputs?

Steve, you mentioned an XBR HDTV earlier on - does it happen to have an i.link input?

Piotr, I'm watch your 25p >>> 60i on HD DVD and with the Flicker filter set to MEDIUM, 99% of the twitter is gone.

But the tree bark is way too soft. (Of course the light was very soft.) So if 5 is too soft and 8 is too hard -- that leaves 6 or 7.

I can go up to MAXIMUM and have a bit of twitter, but still great detail if you use 7 or almost no twitter and good detail.

My instincts tell me 7 was chosen by Sony for a very reason. So 7 seems an obvious choice. But for a film look, you may want a softer look. Just don't use 5 or 8.

Your garage has the perfect ultra thin lines for testing. Not very many things are so thin! I guess I bet 7 will be OK for most shooting. Nothing prevents presets for NORM and presets for brick buildings, etc.

Post both when you get a sunny day.

Steve, you mentioned an XBR HDTV earlier on - does it happen to have an i.link input?

Sony made an XBR about 3 years ago I almost bought because it had an i.LINK. I think Sony has switched to HDMI for better copy protection.

Your garage has the perfect ultra thin lines for testing. Not very many things are so thin! I guess I bet 7 will be OK for most shooting. Nothing prevents presets for NORM and presets for brick buildings, etc.

Post both when you get a sunny day.

Yes, I've chosen these fine lines on the garage wall deliberately:)
I'll be posting raw clips with S=6 and 7 at the first opportunity.

Here is a clip with sharpness 6:

http://rapidshare.com/files/19857440/25p_s_6.m2t

And here - the same fine lines on the garage, but with sharpness set at 7:

http://rapidshare.com/files/19857444/25p_s_7.m2t

Guys, I'll repeat my question from another topic here, as I'm about to order my gear for the V1: does the Manfrotto MN523Pro lanc controller wotk flawlessly with the V1/FX7? Thanks!

OK, finally got Vegas to do the 25p to 24p thing, well that was the easy part.
Finding out how to render it to 24p with pulldown had me confused for while but here it is:

http://rapidshare.com/files/19937797/25PsF_to_24p_60i_2-3_Pulldown_Test-01.m2t

Sorry kind of big (66MB) file.

Shot at S=7, 1/25th some time ago now.

Telling Vegas to remove pulldown on file open seems to yield perfect 23.976 although it's only 2:3 pulldown so I guess that means there'll still be judder frames in there.
Haven't looked at it on a full 1080 monitor as yet but didn't notice any nasties at half res, so far I'm pretty happy with the camera.

OK, finally got Vegas to do the 25p to 24p thing, well that was the easy part.
Finding out how to render it to 24p with pulldown had me confused for while but here it is:

http://rapidshare.com/files/19937797/25PsF_to_24p_60i_2-3_Pulldown_Test-01.m2t

Sorry kind of big (66MB) file.

Shot at S=7, 1/25th some time ago now.

Telling Vegas to remove pulldown on file open seems to yield perfect 23.976 although it's only 2:3 pulldown so I guess that means there'll still be judder frames in there.
Haven't looked at it on a full 1080 monitor as yet but didn't notice any nasties at half res, so far I'm pretty happy with the camera.

Bob, could you tell us how to do the procedure in Vegas.

Thanks Michael.

Bob, could you tell us how to do the procedure in Vegas.

Thanks Michael.

The documentation pretty well covers how to do a frame rate conversion but it makes it sound unduly complex.

Open a 1080 50i project. Manually change the project properties to Field Order None (Progressive). Make certain you have Quantize to Frames On.
Drop the m2t file from the V1 into the project. Set the ruler to Absolute Frames. Move the cursor to the last frame. Either copy the cursor position (left most box under the T/L) to the clipboard or just write down the frame number. This has to be accurate!

Now change the project properties to 24fps. Move the cursor to the same position as it was before i.e. the same frame number. You can Paste the number back into the cursor position box or type it in. This should be a little to the right of where it was. Now Ctl-Drag the end of the clip to the cursor.

You now have 24p!

Sorry if that sound complex still, but the idea is to measure how many frames the original video had and keep the number of frames the same in a 24p project. This means the speed and length will change BUT there's no resampling, all frames stay intact.

Then I rendered to 1080 60i HDV but in the MainConcept mpeg encoder set the frame rate to 23.976 + 2-3 Pulldown and moved the quality slider to 15.

Vegas will render the file with a .m2t extension and although I haven't tried as yet you should be able to PTT this file.

So how will TVs know not to deinterlace 25PsF? There are two methods, cadence detection and flags.

Close but TV's don't read flags because 480p/720p/1080p are not mpeg, it is uncompressed ATSC video frames, an internal pulldown mode works off the cadence only.

Close but TV's don't read flags because 480p/720p/1080p are not mpeg, it is uncompressed ATSC video frames, an internal pulldown mode works off the cadence only.

That's right, which is why 2-3 or 3-2 is so good. There are almost a dozen different cadences used, so a TV can do it's "best" with either real P (no deinterlace sensed by the scanning frequencies) or 24p via interlace. Of course, 720p is perfect.

But it's not simply that 24p is easier to sense, the rules for creating 1080-line buffers from 540-line fields are ABSOLUTE. There is no need for bob or weave or anything. The fields all wind-up back in the original frames where they came from.

Despite this, the majority of HDTV can't sense the cadence perfectly. So if you want perfect P, you need to shoot 720p. Which is why the option of converting 25PsF to 720p50 DVCPRO HD is so attractive. You get 4:2:2 and no loss is rez. Recording back to a VTR can be done by FireWire. D-5 accepts it.