How to reduce flicker effect of CCE encode?

[Butcher Wing]

Hi everyone with knowledge,

I hope someone can advise me on this...

I have been able to successfully encode an uncompressed AVI movie to mpg2 using CCE SP and I'm totally happy with the outcome apart from one thing which I don't understand. During scenes in the movie which I have, for instance.. wooden fences with lots of lines on them, or buildings with intricate carved details in the design or windows with bars on them... I get a kind of crazy flicker effect going on on those particular parts of the image. This weird effect is most commonly seen on people wearing "black and white striped shirts" I think. You know how they create a kind of crazy flickering effect on the stripes?

Well, what causes this, does it have a name and what settings can I play with in CCE to reduce this weird effect?

Thanks alot. :)

P.S - I'm encoding progressive AVI to progressive mpg2 - a high VBR like (max 9000/ avg 8500/min 2000) and 2 pass. All filters were disabled.

Note: This crazy effect is present slightly on the original source dvd video but not as bad or in as many places as the mpg2 CCE produced for me.

[TheSkiller]

Note: This crazy effect is present slightly on the original source dvd video but not as bad or in as many places as the mpg2 CCE produced for me.
Is the source AVI's horizontal and vertical resolution the same as your desired DVD output size? If not CCE has to scale the video. In that case it's very likely that the scaling algorithm causes sharp edges that flicker.

[Didée]

Perhaps the mpeg2 video is okay, but during playback the decoder is set to forced de-interlacing.

[Biggiesized]

It sounds like the scaling algorithm is creating moire.

[Butcher Wing]

Thanks for all your replies. Atleast someone knows what I'm talking about.... hopefully. Then you've all seen this kind of issue before. You even see it on some commercial movie dvds and on tv, but what is it called? ---Moire?--- If so, then atleast I have a name to Google now.



Ok, - My uncompressed AVI is exactly the same as the mpg2 I'm converting to. NTSC 720 x 480 IVTC 2:3pulldown


I'm adding the mpg2 to a dvd via authoring with DVDLabPro and then playing back the mpg2 on 2 different Pioneer dvd players.


I'm guessing I won't find a fix for this problem and it's likely something to do with the original source, since there is evidence of ''moire'' on the original too.


Oh well. I guess I'll just have to put up with it.


What is the most common cause of "moire" then?

-

[TheSkiller]

In case of progressive encodes CCE (any version) never sets the "Frametype progressive" flag (which is said to cause problems on some players, that's why). Thus DVD players usually assume that the video is interlaced. On PCs and progressive scan DVD players in progressive output mode (you know, 480p etc.) this will certainly trigger the players deinterlacing, how much depends on the players ability to detect *actual* interlacing. This can cause what you're seeing.

If it's really that what you're seeing, it's called jagged lines. But it could also be line twittering or both.

Edit: You can use Restream to patch the "Frametype progressive" flag. You can also have a look at the source (demuxed to M2V) to see if it has the "Frametype progressive" set.

[Biggiesized]

http://en.wikipedia.org/wiki/Aliasing

[manono]

In case of progressive encodes CCE (any version) never sets the "Frametype progressive" flag
Eh? Are we talking about the same thing here? Using CCE 2.70.02.12, when in the Picture Quality screen if you check the 'Progressive frame' box the 'Frametype progressive' flag gets set. This can be confirmed by checking with Bitrate Viewer, DGIndex, ReStream, or other apps. Perhaps Butcher Wing didn't set the flag and his player is deinterlacing it, I don't know. Here's a pic from a VOB made from one of several thousand CCE encodes I've done:

[mp3dom]

Probably TheSkiller refers to the "Progressive Sequence" in the sequence extension. Some encoders flag a progressive stream in this way (Frametype Progressive on, TFF off, Progressive sequence on)

[Ghitulescu]

I have been able to successfully encode an uncompressed AVI movie to mpg2 using CCE SP and I'm totally happy with the outcome apart from one thing which I don't understand. During scenes in the movie which I have, for instance.. wooden fences with lots of lines on them, or buildings with intricate carved details in the design or windows with bars on them... I get a kind of crazy flicker effect going on on those particular parts of the image. This weird effect is most commonly seen on people wearing "black and white striped shirts" I think. You know how they create a kind of crazy flickering effect on the stripes?

Well, what causes this, does it have a name and what settings can I play with in CCE to reduce this weird effect?

Thanks alot. :)

P.S - I'm encoding progressive AVI to progressive mpg2 - a high VBR like (max 9000/ avg 8500/min 2000) and 2 pass. All filters were disabled.

Note: This crazy effect is present slightly on the original source dvd video but not as bad or in as many places as the mpg2 CCE produced for me.

There are several details that you forgot to tell us, which details are extremely important.

1. the original source being a DVD why do you converted the interlaced MPEG-2 file into a progressive uncompressed AVI? and which tool had you used? Its settings could have done a lot of harm if incorrectly set

2. are you encoding back to DVD or to a "generic" MPEG-2? because, by standard, all DVDs should be interlaced encoded, even if they contain progressive material. A generic MPEG-2 file is not constrained

3. how did you notice the artefacts? playing the file on a computer (inherently progressive)? in this case did you checked the interlaced/progressive settings of the player? or on a standalone? and paid attention to its settings (on TVs') as well?

[Butcher Wing]

A lot of possible good information here to help me. Thanks alot all of you. But first I need to figure out which one of your suggestions to try out first. 'lol



First off, to "The Skiller" - Thank you for suggesting "line twittering"! I've just googled this for more info and it sounds just like what I'm experiencing. It has to be ''line twitter" I've got here. And very possibly "Jagged edges" too.

So I guess the first thing to do is to learn how to patch a "Frametype progressive" flag - using Restream. Hopefully it's not too hard to learn.

And you're saying even though one ticks the "Frametype progressive" box in CCE, it doesn't apply it? Well that's not on!

And yes, I always ticked the "progressive box" in CCE.

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

"manono" - I'm confused. How come your screen shot shows that your video is both "Progressive" and "Top Field First"? I thought "top field first" was to do with "Interlacing only"?

If not, then maybe I shouldn't have unticked the box that says "Output Top field first stream" in the 'Advanced settings' section of 'CCE'. ?



--------------
Ghitulescu - If I don't find the solution this time, I will post a description of exactly what I did. From beginning to end, with screen shots. :)


Thanks all.

[Butcher Wing]

Update: I checked both the original source and my encoded mpg2 in 'Restream' and both are showing correct as "Frametype Progressive" and "Top field first". Just like 'manono's screen shot.

Guess that isn't the problem then.

The original source is a commercial PAL dvd movie that says it's made from an 'HD master'. So I guess down scaling that to dvd as they have would have caused some of the "twittering lines" in the first place (as I've read). Just can't work out why my mpg2 has it worse and in more places. :/

In case you want to know. It's a 'progressive' PAL remastered movie dvd that I took and converted to "NTSC" properly using Sony Vegas, changed the 'hue' slightly, then rendered as "uncompressed AVI" with all the correct settings. ie: 23.976fps IVTC/ progressive/....

Encoding to mgp2 with - CCE SP ver. 2.70.02. 12

[mp3dom]

Well, if you've converted to NTSC you have scaled the video even more from 576 (pal) to 480 (ntsc). This can explain why you have even more twittering than the source. Also, where are you watching the movie? Even if your conversion is a 24p+3:2pulldown, only on progressive scan tv (or computer monitor) the frame will be displayed at full resolution. If you're watching it on a standard tv-set probably you'll always see it by field rather than frame.
You can try to apply a gentle lowpass filter that you can find inside CCE. It can helps on this kind of problems (at the price of a less detailed image)

[Butcher Wing]

Thanks mp3dom,

I am watching it on a standard tv-set, yes.

I've tried it on both an old old school CRT tv with a big back. That tv usually makes quality look good for some reason. That's why I've stuck with it in my bedroom.

And I've tried it on a Pannasonic 40" plazma on the wall.


So basically I'm stuck with this twittering problem then?
Or I can apply a low pass filter to reduce it but resulting in a softer picture. I'm not keen on that.

Oh well. Atleast I know it's nothing I've done wrong. (I think)

[Butcher Wing]

I need to ask -

There's a box in the ''Advanced Settings'' of CCE SP - that is already ticked by default called "Top Field First Stream".

Even though I have the "Progressive frame" box ticked, this "Top Field First Stream" option is ticked. I have been "un-ticking" it. Is that wrong?

Should I leave it ticked?


Thanks.

[mp3dom]

Have you that problem even on the plasma with a progressive scan dvd-player?
With a gentle Lowpass filter the image will be a little softer only on high frequencies (some noise, edges etc). Middle-lower frequencies will not be affected and will retain the original detail. The detail-loss is not visible on standard tv-set (we're always speaking of SD video intended to be seen on SD tv). It will be visible on HD monitor/tv.

[manono]

Should I leave it ticked?
Your source is progressive so it doesn't make a whole lot of difference what you do. However, I have the 'Output top field first' box checked and 'Offset line' set for 0 (zero) for all of my progressive encodes.

Where you have to be careful is when encoding interlaced material.

[Butcher Wing]

Thanks manono.

And thanks mp3dom, I will try a lowpass filter. Will it make the encoding take alot longer do you know? It already takes around 9 hours!

Also, what settings for this lowpass filter do you recommend? There's so many settings and options, I don't have a clue.

I guess, choose "Natural" and tick the "Low" box. But what to do with the sliders?

Thanks...

[poisondeathray]

9 hours!? for 2pass encoded SD DVD ?

older computer ?

you say uncompressed avi, but are you filtering on top of that ?

[mp3dom]

Feed CCE with an YUY2 lossless AVI file (Lagarith, Huffyuv etc). This will speedup things *a lot*. Don't use AVS that have filtering stage on top. Are you encoding with 9 pass?
Regarding the lowpass filter, you can start from a value of 40 and see the ratio between flickering and detail loss. The filter is fast and should affect the encoding speed only by some marginal value.

[Butcher Wing]

9 hours!? for 2pass encoded SD DVD ?

older computer ?

you say uncompressed avi, but are you filtering on top of that ?

Older computer, possibly, but not that old. It's still pretty good. I'm not sure what is considered 'old'. This one is 2007 I think.

No, no filters. 2 pass, yeah. Maybe it's less than 9 hours. I can't remember for sure. But I have to leave it going all night. How long should it take?

It's a 139GB AVI file - 1hr 39 min movie.


Feed CCE with an YUY2 lossless AVI file (Lagarith, Huffyuv etc). This will speedup things *a lot*. Don't use AVS that have filtering stage on top. Are you encoding with 9 pass?
.

Sorry, mp3dom, that's a bit over my head. I'm a novice at this. I just chose the "uncompressed" codec for AVI in Sony Vegas.
That's what a friend told me to use.

Regarding the lowpass filter, you can start from a value of 40 and see the ratio between flickering and detail loss. The filter is fast and should affect the encoding speed only by some marginal value

Thanks alot, I will give that a go.

[poisondeathray]

How long should it take?

It's a 139GB AVI file - 1hr 39 min movie.




Not that long, not even for a single core P4. Something else must be going on

What are your computer specs? Maybe you have memory issues and are swapping out to page file ?

[Midzuki]

Not that long, not even for a single core P4. Something else must be going on.

I agree. TMPGEnc Plus takes around 8 hours to encode a 2-hour SD movie on an ancient "monocore" Pentium-4. But both HCEnc and CCE are much faster, doubtless.

[Butcher Wing]

I don't know much about PCs but I found this out...

It's an "AMD Semprom(tm) Processor 2800+" it doesn't have an "Intel chip" whatever that means. --- It's not got 'Pentium' mentioned anywhere. It's not that type.

It says 1.47GB Ram, although I've been told it's actually got 2GB Ram. So not sure what's going on there.

I've always thought it was pretty good, untill now. 'lol

Do I have a shite computer?

[poisondeathray]

Yes it's outdated

A modern computer will easily be 8-12x faster

Also if you export from vegas uncompressed AVI, it will be RGB. If you feed it directly into CCE there will be RGB=>YV12 conversion. That will slow things slightly as well

[Butcher Wing]

Yikes! 8-12 x faster?! I'm missing out.

Ok, well thanks for letting me know. Got that cleared up.

Feed CCE with an YUY2 lossless AVI file (Lagarith, Huffyuv etc)

So I install one of these codecs to use with Vegas to gain a bit of encoding speed? Ok, gonna give that a try.

Thanks for your help.


Now I'm gonna go somewhere and think about how crap my computer is and cry. :(