Not sure whats causing this problem

[stigslim]

Its like this.I have an NEC ND1000A drive which i am having problems with, i think.If i view a clip on my PC in whichever format i have no problems watching and it looks fine.Everything goes according to plan when i convert (i have used countless software packages and tools usualy from links on this site) and it does exactly what it says on the tin.I have nearly never had any problems playing my burned disks on stand alone players but, and here is the but.I get what i can only describe as a judder on playback.Its very regular and only really noticable when the camera pans round in a shot.Its almost like a very quick still frame about every second.This problem has been bugging me now for ages and any help you could offer would be great, thanx in advance.My appologies if this post is in the wrong place but this is doin my head in.

[daamon]

Hi stigslim,

What disks are you burning to? Have you changed to these recently?

What is the source material? Divx / Xvid, MOV, DV AVI, WMV etc.

What are you using to encode them, and with what settings?

Try cleaning the lens on the burner... A friend had similar problems to you and he tried all sorts of things. Even though it was a fairly new burner, he resorted to cleaning the lens and all was OK.

[ozymango]

I have nearly never had any problems playing my burned disks on stand alone players but, and here is the but.I get what i can only describe as a judder on playback.Its very regular and only really noticable when the camera pans round in a shot.

I'm not sure I understand correctly, are you saying that you've always had this judder problem when playing these discs on stand-alone players, or is this a new thing? Well, in any case, my hunch is that your source video is non-interlaced, and/or it's being recorded to DVD as non-interlaced (progressive). This would explain why it looks smooth when you play it back on your computer (progressive display) but, during motion scenes on an (interlaced) TV, you get motion weirdness due to frame/field sync issues. There's a technical name for this but I haven't had my coffee yet today so I apologize for any incorrect terminology.

There are bunch of ways to check for this and a bunch of "fixes," depending on your source and software. My next hunch is that you just have a checkbox ticked somewhere in your encoding software that's set to de-interlace the video or preserve the progessive source. That'd be an easy fix, anyway.

Let us know if any of this makes any sense, and what software you're using and we can walk you through a few things to check if this is the issue. Good luck!

[lordsmurf]

Sounds like framerate or interlace errors.

[jtoolman2000]

BINGO!

[stigslim]

Hi sorry about the wait.Right here goes i will try and get everything in.As for source material it doesn't really matter what it is they pretty much all turn out the same.The software i am using right now ranges from Intervideo to Power director or even ulead Movie factory.The disks i am using right now are Bulkpaq allthough i have used many others with no luck.And heres the big one, i converted one last night and mounted the DVD image on Asus DVD software (no burning required) and quess what it still does the same thing even when they play on my PC.So judging by this it aint the burner or the source cos that plays O.K so i'm lost.Any help would be good.

[Nelson37]

Good, you have eliminated media and the standalone player.

Source material - Yes, it does matter for reasons of which I could fill a few pages. I understand it happens on every file you have tried, but you may not be aware that the type of source you are using will tell us a LOT about what could be causing the problem!!!!!!!!!!!

Try reversing the field order, there should be a "top field first" or similar.

IF I had some idea of the type of source video, I might have a few other ideas or be able to eliminate some possibilities.

There is a reason some of these questions are asked. It is not necessary for you to understand why, it is only necessary for us to understand why.

[stigslim]

O.K here is an example, if i get it right.X-Vid Mpeg4 23.976 fps 576*240 855 Kbps (thats the video).Audio, Mpeg layer 3, 48000Hz 131 Kbps.I ecnode to Pal keeping the aspect ratio the same and the highest resolution i can.And to do this i use one of the above programs or DVD Santa.Is this enough?.Be back ASAP to find out what you made of it.(Probably be tommorow).Cheers

[daamon]

I'm no expert on this, so I may be off - but encoding 23.976fps to PAL (which is 25fps) might well be your problem - unless you're doing something to address this that you're not describing...

Like I say, I may be wrong but that caught my eye. I'll leave others to confirm or deny my suspicion.

[Nelson37]

I think daamon got it right, that is most likely it. For test, do one without changing the framerate and play on the PC as before.

The description of the source file immediately pinpointed the problem.

It is possible that it is something else, a description of the final format you are encoding to would nail this down.

Terms like "the highest resolution I can" are extremely unhelpful, and not worth the time it took to type it.

Go to the store and get me a dozen.

[Abond]

mp3 VBR is the problem

[stigslim]

Right lets see.You guys seem to know what its all about. Can you tell me how to see what the final format is, and how to encode without changing the Fps.I dont mean to sound like a complete N00b but to be honest i aint really clued in here as i only really have any experience with all in one packages.And mp3 VBR whats that and why do you think its the problem?.Any helps good cheers

[daamon]

Can you tell me how to see what the final format is?

Use either GSpot or AVICodec. I usually find GSpot v2.52 (beta) gives the most info.

...and how to encode without changing the Fps.

I've never encoded with a source that's 23.976fps - but, from what I've read here, you may well need to encode using "3:2 pulldown". I'll leave others to confirm or deny my guess...

You'll need a tool dedicated to encoding: TMPGEnc Plus, Canopus Procoder, Mainconcept MPEG Encoder, Cinemacraft Encoder etc. (there are others).

I dont mean to sound like a complete N00b but to be honest i aint really clued in here as i only really have any experience with all in one packages.

Hey, no problem - we all started as noobs. You're experimenting, trialling, trying to figure it out and asking questions when you're stuck - much better than: "Hi, I'm lazy and want you to spoon feed me the answers to the simplest questions"...

And mp3 VBR whats that?

MP3 is a way of compressing audio so that filesizes are much smaller, but the audio is still decent (depending on the bitrate used, of course). "VBR" stands for variable bitrate - this means that, throughout the audio, the bitrate varies according to the degree the codec thinks the audio at that point can be compressed. If it can be compressed a lot without affecting quality beyond a threshold, the bitrate is low. if not, it's higher.

It's worth you reading up on how bitrate is used to control quality and why it would vary. It's too much for a quick answer here.

...and why do you think its the problem?

Dunno - Not experienced with encoding from a VBR audio source. I'll leave that for "Abond" to explain...

Hope that helps some...

[stigslim]

Again here we go.I converted again and upon using AVI Codec i got this info.Video 83000Kbps 29.970 fps \res 352*480 Mpeg2.Audio 384Kbps 48000Hz AC3.Now i did convert from 23fps to NTSC instead of Pal and it did improve but still not smooth.Anyway i will have a go with TMPGenc and see how it goes, i will try and keep the frame rate the same.I think ive got you with the VBR but i will read through it again.And thanx for the help, some people are only interested in showing what they know by putting those that dont down.Rest assured i will be back to let you know how i get on.

[daamon]

As it's still doing it, even with AC3 audio, I'm more convinced it's the direct encoding from 23fps to 29.97fps.

I think you need to read up on that "pulldown" I mentioned, before you do any more experimenting - I believe it's a way of encoding properly from 23fps to 29.97fps. I'm in PAL land, so I'm not familiar with NTSC intricacies, so I may be wrong.

An observation: with a resolution of half-D1 (352 x 480), a bitrate of 8.3Mbps (8,300kbps) as reported by AVICodec is quite probably overkill - unless you really do need that high a bitrate. You'll probably get away with something around the 4 - 5,000kbps mark. Try it out... You'll get a smaller filesize with (hopefully) little noticeable drop in quality.

I'm glad you appreciate the help. Those who talk down are only a few, and some people just have bad days...

Good luck...

[Nelson37]

23 and 29 are both NTSC. 23 requires insertion of a Pulldown flag which instructs the player to insert a fifth frame out of every four to smoothly convert to the higher framerate. To change the framerate from 23 to 29 in software could very well cause the same issues as changing from 23 to 25.

In short, changing the framerate is usually a bad idea and causes many issues.

Repeat suggestion - do a test without changing the framerate. Look for a 3:2 pulldown on playback selection, make sure you do not select Inverse 3:2 pulldown, that is the reverse.

The conversion of 23 to 29 is standard, performed in hardware, and necessary. It is not an encoding change, merely an inserted instruction.

I would suggest reading up on some of these issues as there is a lot of ground to cover, it is a load but it will gradually begin to make more sense as you go along.

I do not believe VBR audio is your problem, this usually leads to synch issues, not video stutter.

[stigslim]

Hi again, sorry to keep goin on at all you guys but i am pretty clueless.Whats this about a pull down flag? do you mean i TMPGenc or something else.Like i said sorry if all the questions seem dumb but i sort of get where your coming from but dont have much experience with the software.Cheers

[stigslim]

Back again .Now i had a go with TMPGenc Plus and got on pretty well.The clips i have encoded seem to be much better, and will probably improve even more when i learn how to tweak an encode.The ones that i encode from PAL seem spot on but the ones from NTSC look much better but never really cut the mustard in comparison.Now this question, very fine lines upon playback.Now i know your sayin interlace problems (believe it or not i actually worked that one out).But how can i put this right the only options i get are interlaced or non interlaced, do i need to use some other software?.Cheers guys i am finally getting there, and its been a while.
P.S sorry about that last question it was a bit dumb.

[daamon]

Hi stigslim,

Good to hear you've made a leap forward... Here's a guide I found very udeful when I started out with TMPGEnc Plus.

www.videohelp.com/guides.php?guideid=303#303

(Don't forget to rate it if you use it...)

The issues it raises with encoding audio can be got around by setting TMPGEnc to use external encoders (tooLame and SSRC).

When you say "fine lines on playback" - is this in the PC or a TV? I ask coz PC monitors display a "progressive" image as opposed to TVs which display an "interlace" image (read up on the two words in quotes, and the differences between them).

In short, interlaced footage displayed on a monitor looks crappy, due to the interlaced frames being displayed at the same time, but one of the frames is slightly ahead and so the image is slightly different - hence the problems.

Using something like WinDVD or PowerDVD will negate this problem, as it displays an interlaced image on a progessive monitor without the interlace effect.

If you are seeing these lines on a TV, try reversing the field order when you're encoding (i.e. if you're doing "bottom field first", try "top field first" and vice versa).

Of course, these lines may be an inherent result of doing the pulldown - I don't know, as I've never done pulldown.

[Nelson37]

When you say PAL works and NTSC is not as good, are you still changing the framerate on the NTSC conversion or not?

This will pinpoint the problem as not being a PAL vs NTSC issue but rather a changed vs unchanged framerate issue.

I will again suggest doing some reading. There are many pages of explanations on interlacing issues on this site, often the key to understanding is to read several different descriptions of the same thing. I know for me, the first few did not make sense and/or used other terms I did not fully understand to describe the issue. After reading several different guides and discussions, both the related terms and the specific problem became much more clear. Also, several more unrelated but necessary to understand concepts also became clear. That is why I went on to read every single guide on this site, several of them 3 or more times.

Do you really want my or somebody else's 2-line description of an issue when you are surrounded by Encyclopedic articles which have been rehashed and refined over several years, by a number of experts, specifically for the benefit of newcomers such as yourself? The Cliff Notes version will almost certainly leave out things you need to know.