HSJS 2 - DVD jerkyness anyone?

[Dave]

Hello everyone,

Perhaps it's me but when I play the short DVD accompanying "Hayley Sings Japanese Songs 2", I find that on my large screen TV, the video is noticeably jerky when the camera pans across a scene, much more than I see on broadcast TV or my normal DVDs.

This DVD was produced using the NTSC TV system and I wonder if anyone else has noticed jerkyness when the camera pans, particularly members in Countries using the PAL TV system (UK, Australia, NZ, Ireland, Germany etc.). There may be no problem in "NTSC" Countries e.g. Japan, the US and Canada etc. but I cannot be sure about that as it could have been made in PAL (NZ) then converted into NTSC for the DVD.

I see the same effect on "Live in NZ" when the rolling clouds are shown on the big oval TV screen on the stage: that is also an NTSC DVD, Worldwide.

Before I speculate about what may be causing this, I'd be interested to know if anyone else sees this jerkyness on camera pans or the rolling clouds on the HSJS2 DVD (or Live in NZ cloud scenes). If I am the only one, I may need a new DVD player!

Or if there are any other problems with it, please say so!

Cheers, Dave

[comet]

as I grow older or maybe it is the digital flatscreens which cause this Jerkyness ( What a lovely word jerkiness )
I find a lot of panned shots produce digital shudders, particularly on football or motor racing where there is constant panning across lines that are just slightly off horizontal, which can be particularly irritating , so much for High Definition not to good on skin tones either

I suppose it may have something to do with the number of dots or pixels per inch on the screen in relation to the number the scene was recorded at.
Then you have moving lego bricks instead of sloped lines.

Hard to beat a good 70mm film projector.

A good excuse not to watch too much telly..

[John]

Hi Dave

It was shot 1080P 24 frame as per instructions from Japan.
They then appear to have edited in NTSC 30i (or edited in HD then down-converted)
You are now watching in PAL 25i
As the frame rates change the motion can get jerky.
Going from 24 to 30 frames per sec requires some extra frames to be added then most of those are taken out when converting to PAL (but probably not the same ones)
Maybe some day it will be released for broadcast in full HD

[comet]

Well Hi John,
Thanks for the info,
I hope to take a closer look at Mona Vale real soon'

Welcome to the forum and thank you for your valuable contributions.

[martindn]

What a coincidence. I was just watching that DVD five minutes ago on my laptop. And yes, it was a bit jerky, but I also got a couple of those pauses that you get when Windows decides that something else is a more imporant task for the CPU than playing the DVD, and I put it down to that.
And yes Paul, I have tried to do frame rate conversions on videos before now, and given up becuse of some of the wierd effects you can get. So it wouldn't surprise me if frame rate conversion was not the cause of it.
Martin

[postscript]

Apr 6, 2009 19:25:03 GMT comet said:

as I grow older or maybe it is the digital flatscreens which cause this Jerkyness ( What a lovely word jerkiness )
I find a lot of panned shots produce digital shudders, particularly on football or motor racing where there is constant panning across lines that are just slightly off horizontal, which can be particularly irritating , so much for High Definition not to good on skin tones either

I suppose it may have something to do with the number of dots or pixels per inch on the screen in relation to the number the scene was recorded at.
Then you have moving lego bricks instead of sloped lines.

Hard to beat a good 70mm film projector.

A good excuse not to watch too much telly..

Is it possible we are not defining 'High Definition'? Is it 1080i or 1080p (UK orientated) and is it 'as is' or scaled up? and what engine is in the receiver? Is it at 50Hz or 100Hz, the later models designed to reduce 'blur', which may not be what you are describing?

No I am NOT technically-minded. I just happen to be following things from the perimeter for when I upgrade my analogue stuff (for home entertainment, not PC-orientated). My equipment is still over a quarter of a century old! And still working fine, especially when we have these ads showing us how much better pictures look on HD--they still look fine to me on my ancient analogue stuff

Peter S.

[Dave]

Apr 6, 2009 20:50:34 GMT John said:

Hi Dave

It was shot 1080P 24 frame as per instructions from Japan.
They then appear to have edited in NTSC 30i (or edited in HD then down-converted)
You are now watching in PAL 25i
As the frame rates change the motion can get jerky.
Going from 24 to 30 frames per sec requires some extra frames to be added then most of those are taken out when converting to PAL (but probably not the same ones)
Maybe some day it will be released for broadcast in full HD

Thanks very much John, for your insight. That confirms my suspicions, though I didn't know until now that it was originally shot at 24 fps full HD. What a treat it would be to see it as recorded but I suspect that we never will.

With difficulty, because the DVD is encrypted, I managed to extract the video to analyze it and yes indeed, every fifth frame is an exact duplicate of the preceeding frame, so undoubtedly, that is causing the jerkyness when the camera pans (the faster it pans the worse it gets). For members who don't know, the extra frames that were inserted increase the speed from 24 fps to 30 fps (well 29.97 but that's another story) which is the frame rate for the NTSC broadcast TV standard used in Japan and North America. The duplicate frames add no extra information and introduce that jerky effect on certain scenes, at a rate of six times a second.

What I completely fail to understand is why Universal in Japan wanted it recorded at 24 fps in the first place because they must have (or should have) known the DVD would be released at 30 fps in standard definition and that it was unlikely to ever be released for the cinema or HDTV (24 fps is what celluloid cinema films are shot at, perhaps it is also the standard for HD video shoots?).

All this means, I think, that the amount of jerkyness (on the scenes affected) will be similar for everyone, be they in Japan, the US, in PAL TV Countries like the UK and NZ and even when played on a PC. It's probably no worse in PAL Countries than the others, because most PAL equipment will automatically play NTSC material correctly. The problem could have been completely avoided by asking for the videos to be shot at 30 fps.

Universal Japan, this isn't a very good way to do business (though I still love the videos, just not quite as much!).

Cheers, Dave

[John]

Hi Peter (with apologies to everyone else for the technical jargon which may be considered off topic)

You are right when you say there are several versions of HD
When the HD specs were conceived I hoped that we would eventually get 1 common format for the whole world but that has not happened
The current highest def in common usage is 1080p (1920x1080 pixels) 720p is 1280 x 720
To confuse everyone there is another standard called 1080i
The p stands for Progressive, every frame is like a film frame with a complete copy of the image.
i means interlaced where each frame has 2 fields, the first field has the even numbered lines and the second has the odd numbered (or it could be the other way around - I forget)
What that means is 1080p50 is 50 full frames of information per second while 1080i50 is only 50 field or 25 frames per second.
1080p is twice as much data as 1080i
720p is similar in data requirements to 1080i
In New Zealand TV3 and Sky transmit 1080i50 and TVNZ transmits 720p50.
The BBC has said 1080p50 will be the only acceptable spec from 2011 on.
The number on the end is the number of frames for p or fields for i
In PAL countries 50 is the norm. In NTSC countries I assume 60 is the norm.
Film is 24p.
The HSJS2 videos were shot 24p to give it a more film like feel.
In New Zealand 1080p is called Full HD while 1080i/720p capable equipment is call HD ready.

This is a real minefield for people purchasing new HD TVs.
The HD ready TVs are much much cheaper and I'm not sure the sales people really understand the difference.
They can get away with it now but when Blue-ray HD players become more common and films come out in HD at 1080p people will start to see the difference between the 2 types of TV.

So in Analogue TV we only had 3 standards to deal with PAL, NTSC and SECAM
Now whe have 1080p60, 1080p50, 1080p24, 1080i60, 1080i50, 720p60, 720p50 and 720p24

To bring us back to the topic, when we were asked to shoot 1080p24 we assumed that the music vids were for Japanese TV which I understand is all HD.
On reflection, we probably shouldn't have used as many big crane moves as 24p only has 24 frames per second which means pans can become jerky.
I can assure you that the original HD footage looks stunning, the crane moves look fine and I hope at some time in the future that Universal Japan release a HD version for TV.

[Dave]

Hi John,

Thanks for the explanation, I understood it and it was helpful. I've now figured out how to remove the duplicated frames used in Japan to increase the frame rate from 24 to 30 fps, and which are responsible for introducing a bit of jerkyness on a few scenes.

I cannot post more than half a minute or so of the "before" and "after" videos for obvious reasons, but for the benefit of any members who may be interested and who aren't sure what we are on about, I will post about half a minute from the start of Track 1 (Tsubomi (Buds).

Short Sample as on the DVD at NTSC frame rate (converted in Japan from 24 to 30 fps)

Same Sample at the original 24 fps as filmed (extra frames removed).

I've done it in Windows Media format at 2 mbps video so most members who are interested should be able to download and play them.

What I see is smoother video in the second "corrected" version - although it's not perfect because, of course, it's only 24 fps and we are viewing it on a computer. I know the movie industry uses this as a standard but I don't see why Japan should have requested it when they knew it would have to be converted to 30 fps for the DVD, it's annoying. Perhaps it was for HDTV advertising?

But I still love the videos, the corrected versions are even better and possibly a bit closer in smoothness to the originals? Excellent video and with stunning sound quality too!

Cheers, Dave

[martindn]

I find this a fascinating insight, since I am only now learning about such things. As a professional engineer I had no difficulty undertanding your post John, but even so I don't think it was over-technical.

Dave,
The panning in both of your samples looks jerky to me during the pan at the start. The second one might be marginally better, but now that I have been alerted to it, I find it very noticeable.

I think John is right, the root problem is the 24fps. There is nothing that can be done to overcome that unfortunately. And it must look the same in Japan too.

Martin

[Dave]

Apr 8, 2009 21:12:32 GMT martindn said:

I find this a fascinating insight, since I am only now learning about such things. As a professional engineer I had no difficulty undertanding your post John, but even so I don't think it was over-technical.

Dave,
The panning in both of your samples looks jerky to me during the pan at the start. The second one might be marginally better, but now that I have been alerted to it, I find it very noticeable.

I think John is right, the root problem is the 24fps. There is nothing that can be done to overcome that unfortunately. And it must look the same in Japan too.

Martin

Hi Martin,

Yes of course, John is exactly right (he's the expert!) and it's just one of those things that some people are sensitive to jerkyness/judder during fast panning/crane shots at 24 frames a second. Conversion to 30 frames/sec tor NTSC (as for this DVD) makes it a bit more noticeable to those who don't like it, because of the duplicated frames, but not everyone is bothered by it. Some people apparently love the "film feel" of video recorded and played at 24 fps but personally, I've never understood the logic of that - judder is judder and it irritates me!

I think it's something we don't notice as much in PAL TV Countries (say on cinema films shot at 24 fps then shown on TV) because they don't convert the frame rates as such, no extra frames are added. They just speed them up and play them for TV at 25 fps so they are 4% faster, 4% shorter... but no extra judder. The audio would normally increase in pitch when this is done but this can be fixed so the pitch is the same and of course the audio always plays 4% faster.

I can illustrate this using the same clip as before: using the "corrected" 24 fps version, I have speeded it up to play at 25 fps (like PAL TV) and kept the audio at the same pitch, but it too is 4% shorter! The judder should now be slightly less than before and in places is, I think, noticeably less than the original DVD 30 fps version. But in the end, it's a matter of personal judgement and many people aren't bothered at all by these things.

Same Sample speeded up from 24 fps to 25 fps (no added frames).

I've learned a lot today!

Cheers, Dave

[postscript]

Apr 7, 2009 22:17:34 GMT John said:

Hi Peter (with apologies to everyone else for the technical jargon which may be considered off topic)

You are right when you say there are several versions of HD
When the HD specs were conceived I hoped that we would eventually get 1 common format for the whole world but that has not happened

...The HD ready TVs are much much cheaper and I'm not sure the sales people really understand the difference.
['Do not understand' or choose not to know?]
They can get away with it now but when Blue-ray HD players become more common and films come out in HD at 1080p people will start to see the difference between the 2 types of TV.

So in Analogue TV we only had 3 standards to deal with PAL, NTSC and SECAM
[when (although expensive but good quality equipment but therefore it lasted--I'm still using mine after twenty-five years) it was comparatively simple to obtain VCR and monitor that automatically covered all three! So in many ways going forward with better picture definition we have actually gone backwards in terms of ease of use and interactivity!]

To bring us back to the topic, when we were asked to shoot 1080p24 we assumed that the music vids were for Japanese TV which I understand is all HD.
On reflection, we probably shouldn't have used as many big crane moves as 24p only has 24 frames per second which means pans can become jerky.
I can assure you that the original HD footage looks stunning, the crane moves look fine and I hope at some time in the future that Universal Japan release a HD version for TV.

[/size]
That last paragraph, John implies your personal involvement and if I have missed such detail from your earlier five posts I will now check them out. Failing that perhaps you would enlighten us?

I would not presume to comment for Dave, as I suspect he already knew all that you have said but I am sure I am not the only UK person who has not yet committed to upgrading for future BBC intentions (we don't finally go over nationally until 2012, the largest populated area being the last to go over) wanting to be sure that what we go for IS the latest standard.

Thanks, John. I personally believe we remained on topic and regardless I think we have enlightened many most usefully.

Peter S.

[postscript]

Apr 8, 2009 19:20:46 GMT Dave said:

Hi John,

Thanks for the explanation, I understood it and it was helpful. I've now figured out how to remove the duplicated frames used in Japan to increase the frame rate from 24 to 30 fps, and which are responsible for introducing a bit of jerkyness on a few scenes.

I cannot post more than half a minute or so of the "before" and "after" videos for obvious reasons, but for the benefit of any members who may be interested and who aren't sure what we are on about, I will post about half a minute from the start of Track 1 (Tsubomi (Buds).

Short Sample as on the DVD at NTSC frame rate (converted in Japan from 24 to 30 fps)

Same Sample at the original 24 fps as filmed (extra frames removed).

I've done it in Windows Media format at 2 mbps video so most members who are interested should be able to download and play them.

What I see is smoother video in the second "corrected" version - although it's not perfect because, of course, it's only 24 fps and we are viewing it on a computer. I know the movie industry uses this as a standard but I don't see why Japan should have requested it when they knew it would have to be converted to 30 fps for the DVD, it's annoying. Perhaps it was for HDTV advertising?

But I still love the videos, the corrected versions are even better and possibly a bit closer in smoothness to the originals? Excellent video and with stunning sound quality too!

Cheers, Dave

Delighted to feel you were able to build on the discussion as I thought you would, Dave. I think it would be interesting to know on what computer you (and anyone else) used for viewing, or perhaps screen.

Initially, I thought the first version was smoother but running both again I noticed MINUTE jerkiness (best expressed as a lack of smoothness) in the first which I had not noticed before, while the jerkiness in the second seemed smoothed out somewhat. Whether the computer 'learned' from the first pass I don't know but I was viewing from a MacBook Pro.

Peter S.

[jordi]

I have watched the DVD on a 24" HD-Ready, and on an Apple Imac 24" full HD.
In both, the jerkiness was noticeable in the pannings. Plus, if I try to watch the DVD on the imac full screen, it gets worse, all edges go sawtooth-like. Pity they did not left it at 24pfs; as Dave's work shows, it would be quite better.

[gra7890]

Hi Everyone,
I am catching upon things and have just got round to playing this
I don't know if it is because I have excellent equipment, or that it is not sensitive enough ...... but it plays fine with no jerkyness

I really enjoyed the two songs and the photo's i.postimg.cc/9fYxy370/smilie-big-grin.gif

Best Wishes,

Graham