Video Deinterlace question

[nddcndndd]

Hi. Here is my problem. I have among my video players BSplayer Pro and VLC. I’m using K-Lite Mega codec pack v3.30 (Full Installed I think without missing codec’s). When I play certain *.vob, certain *.m2v and one converted from VOB to DivX Avi(Using “Total video converter) files with my default player (BSplayer Pro). I get these horizontal periodical flicker lines which lower the quality. They appear periodically in a different period of a few seconds in the mentioned files and look like waves in the video (I hope you by now know what I’m talking about, because this is the best way I can describe it). The same thing I get when I play them with VLC, but VLC has a deinterlace option and I noticed that when it is set from disabled(it’s default) to something else like Blend, Linear or Mean these lines disappear. What is this all about? How can I modify my files so when I play them with BS player I get the same effect as with VLC (with the deinterlace thing)? Is this from the settings, codec’s or the files? Is there an option like this in BSplayer? I’m looking for a solution in which I don’t have to manually change settings for these files every time and play them with BSplayer. What are these lines and this deinterlacing all about? Ask if you need more information.

Please help if you can and thanks in advance!

[edDV]

VLC in Blend, Linear, Mean or Bob mode is deinterlacing the video playback but leaves the file unchanged. I'm not sure what "X" does.

Disable is the same as deinterlace off. Discard means one field is discarded (not played) while the other plays. Single field playback will have half motion smoothless and half vertical resolution but takes the least CPU power.

I've never used BSplayer.

[nddcndndd]

Thanks for the quick reply. I understand now deinterlacing-thanks again. I have a second question regarding the waves. Can I fix that and what are the waves all about?

[jagabo]

what are the waves all about?

Something like this?



That is what happens when you resize interlaced video without first deinterlacing.

[nddcndndd]

Something like this?

No. Here’s a screenshot. They appear when it isn’t deinterlaced and are periodical in the video (not all the time), but are always in the same moments and are always horizontal like this, but are of different quantity. If you want I can post a screenshot of a moment without them. They appear when I just play the video. No setting changes. Thanks for the reply. I hope you can help me some more. Thanks again.

[jagabo]

That's simply what interlaced video looks like on a progressive display when not deinterlaced. Each frame of video contains two half-pictures, called fields. One is contained in all the even numberd scanlines, one in all the odd numbered scanlines. When you watch this on an interlaced TV you see only one field at a time. When you see it on a progressive computer monitor you see both fields at the same time.

[nddcndndd]

I think I get it. These videos are meant to be played on a TV, but I’m playing them on my computer and because of the progressive scan I’m getting this. So is there a way I can fix this so when I pay them on my computer I don’t get the lines? Maybe modification to the files? Or maybe turn off progressive scan when I play them? I’m new to this things and I don’t know what can or can not be done. And is this possible without deinterlacing manually every time and is it possible to fix this without loss of resolution?

[jagabo]

Use a player that deinterlaces on-the-fly, like VLC. Many players have deinterlacing features.

It's possible to deinterlace and reencode as a progressive video. But all deinterlacers are imperfect. You will create a files with imperfections forever. A deinterlacing player may be just as imperfect, but tomorrow a better deinterlacer may be used and your interlaced files will play better.

[edDV]

Bottom line, for a TV (PAL/SECAM) as the target display, you shouldn't alter the file. You should just alter your method of display on the computer if this is bothering you. Interlace is normal and necessary for a PAL/SECAM display.

VLC is free. Other more automated video playback viewers are PowerDVD and WinDVD. If you play back with VLC, you need to turn on deinterlace under the "Video" menu. Easiest to use is "mean" deinterlace. Other options are blend, bob and linear.

Many of us that work with interlace video day after day don't always use a deinterlacing player. We learn to see past the split fields while editing. It is also possible with advanced editing programs to monitor the timeline on an interlace display using IEEE-1394 out.

[nddcndndd]

Ok. I have some new questions so I’m resurrecting this subject. I uninstalled the latest version of K-Lite codec pack and installed the latest version of CCCP (I have problems with playing some files in VOB and RM, but that is something that doesn’t bother me right now). This seems has solved my problem with the playback of the original files that needed deinterlacing. When I play them with a player using the installed codec’s it seems only the first 1-2 seconds the lines appear and then the video looks like it’s automatically deinterlaced( I mean the lines disappear like they were never there and the player shows that it’s playing the files with their original resolution). All of the files that can run with these codec’s and needed deinterlacing before, now are OK. But here is the new problem some of these files in *.vob were too big for me so I converted them with “Total Video Converter” in DivX *.avi, but the converted files again have the same interlacing problem like before even played with the player using the codec’s. I can’t understand this. I thought converting programs use the installed system codec’s. What’s with this? So please help again.

[edDV]

Can you take a frame grab and post an example? It seems like you performed a poor software deinterlace and have encoded a file with the error in the video.

Dixv compression usually requires deinterlace as a first step. If you are going to deinterlace, do it before you resize the video or you get the result that Jagabo posted above.

If you want to preserve interlace with mild downsizing (TV as target display) consider 352x576 MPeg2 which is DVD compliant. The file size is half but interlace is preserved for quality TV scan.

[Alex_ander]

If you have converted your interlaced video from VOB to divx and resized it vertically at this (e.g. for correcting AR) without (or prior to) deinterlacing, you might have gotten artifacts (like combing bars wider than one line) not repairable completely.

[nddcndndd]

I will try to show what I mean, because I’m not 100% sure I understand what you are saying. If you are asking if I got the waves from Jagabo’s screenshots, the ansuer is-no. Here is what I mean(Sorry, I probably should have posted them earlier).The first one is from the Vob file played with BSplayer usind the CCCP codec’s:



The second one is fro the converted DivX Avi file at the same second again played with BSplayer using the CCCP codec’s. I converted the file after installing CCCP. Before with the K-Lite codec’s the vob file had the same playback like the converted file, but I’m mentioning the last thing just to give some not so important information.

[edDV]

What exactly are you complaining about? That just looks like a highly compressed image.

Update: I responded before the second image loaded. If the split fields were encoded into the progressive frames, it can't be fixed.

[nddcndndd]

What exactly are you complaining about? That just looks like a highly compressed image

Sorry I was a bit slow on editing my post with the second screenshot

Edit: Isn’t there any way I can again convert the file and prevent the split fields from being encoded in the frames? I see that you clearly said: it can’t be fixed, but I just had to ask.

[jagabo]

I suspect all that's happening is the player is deinterlacing when it plays the VOB file, but not when playing the Divx file.

[nddcndndd]

I suspect all that's happening is the player is deinterlacing when it plays the VOB file, but not when playing the Divx file.

That’s what I thought, but the player fixes also files which had this problem in *.mpg and *.m2v I suppose it should fix all formats, but when I think about it some vob file it doesn’t play(only sound but no picture) and plays other vob files without problems and fixes them. I will convert the files in mpg and m2v and tell you the results

Edit: I converted the files in .mpg and the result is completely deinterlaced small (before 200mb-now30mb) file with 0% lines, but with loss in resolution and overall quality like mentioned in an above post. But I suppose Jagabo is right, because when the player plays the DivX file I suppose it uses the DivX codec instead of the codec which automatically fixe the playback (I should have guessed it before ). Now I need someone to recommend me formats that will make the file smaller with very little or no loss, like DivX. The files are about 200mb I want them to be about 110mb or less.

If you want to preserve interlace with mild downsizing (TV as target display) consider 352x576 MPeg2 which is DVD compliant. The file size is half but interlace is preserved for quality TV scan.

Edit2: Now I tried Mpeg2 in NTSC TS stream (whatever that is), but the file is still too big 196mb and it seems it isn’t played by the fixing codec. However I think I got it up and running now and maybe need to try every format until I get one that I’m happy with and can you tell me which format results in a .m2v extension or maybe recommend me something else. Anyway my problems are pretty much solved and a BIG load of THANKS and virtual beer go out to edDV, Jagabo and Alex_ander

[jagabo]

VOB, MPG, M2V, MPV, TS are all MPEG formats. I wouldn't expect a player to handle them differently (unless you encode without the interlace flag).

edDV was suggesting you reduce the resolution by half on the horizontal axis. Fewer pixels per frame means less bitrate needed to encode. So encoding at 352x576 instead of 720x576 will allow you to use less bitrate.

Divx and Xvid have the ability to encode interlaced but most players will still not deinterlace on the fly. You have to manually tell them to.

If you really want to reduce file sizes your best bet is to deinterlace and use Xvid or Divx. X264 will give even better compression but will take a lot longer to encode and more CPU resources on playback.

Try Donald Graft's Smart Deinterlace filter for VirtualDub with the Edge Directed Interpolate option. A faster and dirtier option is to use VirtualDub's built in Deinterlace filter with Discard Field 1 or Discard Field 2, followed by a resize to whatever final frame size you want (discarding a field leaves you with a half height image).

Some interlace info: http://www.100fps.com/

[manono]

And if it's a movie, the chances are good that the fields are just phase shifted and can be fixed with a simple field matcher (AviSynth's Telecide from Decomb, or TFM from TIVTC). An untouched 10 second sample of the source might help to sort it out.

[nddcndndd]

Some interlace info: http://www.100fps.com/

I suppose I’m getting annoying after all the help . But after reading the info from the link I noticed that the codec that fixes the files is “CyberLink Video\SP decoder” which I noticed has a “Bob” feature that is automatic and the mouse teeth appear after it is turned off. All of the converted files are played with the “ffdshow video decoder” which I think is the reason for the difference. I’m asking if I can in some way make things the was so the converted files (the old ones or new ones) be played with this “CyberLink Video\SP decoder”. I’m not sure if I succeed that it will change anything, because I tried virtualDub and I could see on the avi file that it is resized(because of the deinterlacing) but the lines are still in the video because I suppose in the conversion they got printed on the frames(the Last sentence is something that I’m 99% unsure about).

[jagabo]

I’m asking if I can in some way make things the was so the converted files (the old ones or new ones) be played with this “CyberLink Video\SP decoder”.

Cyberlink's decoder only decodes MPEG. You can't use it to decode Divx, Xvid, or x264.

I’m not sure if I succeed that it will change anything, because I tried virtualDub and I could see on the avi file that it is resized(because of the deinterlacing) but the lines are still in the video because I suppose in the conversion they got printed on the frames(the Last sentence is something that I’m 99% unsure about).

Yes, if the video was resized before deinterlacing then saved to an AVI file, the video is forever corrupt. You need to deinterlace the original interlaced source video before resizing. VirtualDub can't read MPEG 2 files. You need to use VirtualDubMPEG2 or VirtualDubMod for that.

Here's your JPG image from earlier deinterlaced and resized to 640x480:



It's not as clean as you could get from the original MPEG 2 file because I had to start with a JPG image.

[nddcndndd]

Here's your JPG image from earlier deinterlaced and resized to 640x480

How did you do that?

Deinterlace before resizing with the converter? How do I do that? I tried VirtualDubMPEG2, but the playback is something that I’m not sure what I’m seeing(again I can see resizing of the frames, but I’m not sure if I’m seeing lines or not) even on one of the videos the picture got pastel like so I will try to do what you say after(if) you answer.

[jagabo]

Just do the whole conversion in VirtualDubMPEG2:

1) File -> Open Video File
2) Video -> Filters -> Add -> Deinterlace -> Discard Field 1
3) Video -> Filters -> Add -> Resize -> select size you want, Lanczos3
4) Video -> Compression -> Xvid -> Configure -> select options
5) Audio -> Full Processing Mode
6) Audio -> Compression -> select codec (LAME?) and parameters
7) File -> Save as AVI.

[nddcndndd]

I tried this: first time

1)-
2)->blend fields together
3)->640x480,Nearest neigbor
4)->ffdshow video codec(didn't find Xvid)->Configure:encoder-MPEG4, FOURCC-Xvid, Bitrate-900kbps
5)-
6)->MPEG Layer3(didn't find LAME MP3)->56kbit\s,24000Hz,Stereo
7)-

secont time:

1)-
2)->Discard Field 1
3)->640x480,Lanczos3
4)-ffdshow...->encoder-DivX 3, FOURCC-MP43,Bitrate-900kbps
5)-
6)->same
7)-

Results: completely deinterlaced video with good resolution. And very lowered quality because my videos are mainly dance videos with lots of movement ant where the most movement is the picture is like a chess board. The file size is about 28mb. I can afford bigger files. Could you tell me settings that preserve maximum quality?

[jagabo]

I tried this: first time

1)-
2)->blend fields together

I think blend is the worst choice. It will look like double exposures when there is a lot of motion. Try Discard Field 1 or 2. It will leave jaggy edges if the video is very sharp. Download and install Donald Graft's Smart Deinterlace filter http://neuron2.net/smart/smart28b1.zip and try Edge Directed Interpolate. That usually gives the best results although a little bit of interlacing may get through at times (I often follow with VirtualDub's Blur and Sharpen(~40) to get rid of this).

3)->640x480,Nearest neigbor

Nearest Neighbor is the worst choice. You almost always want to use Lanczos3 in VirtualDub.

4)->ffdshow video codec(didn't find Xvid)->Configure:encoder-MPEG4, FOURCC-Xvid, Bitrate-900kbps

900 kbps CBR is too low for a 640x480 frame. Switch to target quantizer encoding or 2-pass VBR. Try traget quantizer with the quantizer set at 3 or 4. Install the Xvid codec if you want to use it directly.

5)-
6)->MPEG Layer3(didn't find LAME MP3)->56kbit\s,24000Hz,Stereo

Windows' built in MP3 encoder is crap. Install Lame ACM.

secont time:

1)-
2)->Discard Field 1
3)->640x480,Lanczos3
4)-ffdshow...->encoder-DivX 3, FOURCC-MP43,Bitrate-900kbps
5)-
6)->same
7)-

Results: completely deinterlaced video with good resolution. :) And very lowered quality because my videos are mainly dance videos with lots of movement ant where the most movement is the picture is like a chess board. :( The file size is about 28mb. I can afford bigger files. Could you tell me settings that preserve maximum quality?

As noted above, try target quantizer encoding with a quantizer of 3 or 4.

ffdshow:



xvid:

[nddcndndd]

Caching 8)

VICTORIIIIIIIIIIIIIIIIIIIIIIIIII.
That really did the trick! Just what the doctor ordered!!!!!(I’m not a doctor)
The Avi file is with better quality than the original and is almost 115mb. :P

Now I can only show you the fruits of your help->




I hope one day they make interlacing illegal. :P

By the way I got this message in one of the files, but anyway I’m so happy mayna (Bulgarian Talk).





Edit:^^^^^Fixed it by leaving the audio on “direct stream copy”
Edit2:Another thing in one of the videos in the source video (and in the avi file) when it plays I get like light flickers as if the mater is flicking, but with no actual difference to the picture, like the brightest part of the picture is glowing. This is when it’s running when I pause you can’t really see the flickering. It’s on parts of the picture like this (notice also the little blue spots, that’s all that you can notice in pause.->

Edit3:Nice and useful info I hope you didn’t write it just because of

I hope one day they make interlacing illegal

I was joking you see

[edDV]

When you deinterlace (discard, blend, edge detect) you are making the motion less smooth on a TV display. A progressive computer display can't show one field at a time (50 fields/sec) so you get two time samples in one frame at half the rate (25fps).

This isn't the fault of "interlacing" it is the fault of the computer display. There is one method of deinterlacing that preserves motion detail called a bob. A bob interpolates a frame from each field (calculates the non-existent opposite field) for a 50 fps rate. This keeps motion smooth but has twice the information (more bitrate required) and when done imperfectly has vertical judder or flicker. More sophisticated pixel motion adaptive techniques are needed to maintain quality through a deinterlace.

This is why maintaining interlace is the best method if an interlace TV is your target display. The video will look better on the TV at 1x size (or half horizontal) in its original interlace form

Deinterlace is used for two main reasons. First reason is to improve display on a progressive monitor. For this it is best to deinterlace at or near the point of display (e.g. in a software player or with deinterlace hardware in the display system). Typical deinterlacing software players are VLC, PowerDVD and WinDVD. Hardware deinterlacing is done in advanced computer display cards, progressive DVD players and digital TV sets.

The second common reason to deinterlace is to maximize data compression usually at the cost of image quality. That is what you are doing to get 640x288 or less with bitrates down below 2Mb/s. For stream compression, bob deinterlace isn't an option because it doubles the bitrate so the first thing you give up is 50 motion samples per second. You now have 25. Then you go to work compressing the image with in frame raw compression and interframe motion compression. The latter records motion over picture groups (GOPS) with one full frame and pixel change data for other frames in the group.

HDTV is taking quality in the other direction. In that application picture quality is the goal and compression is used to preserve as much quality as possible using realistic bitrates (6-25 Mb/s). The first dispute over quality resulted in a split between those wanting highest image resolution (e.g. movie and still snobs) vs. those wanting motion accuracy with progressive stop motion capability (e.g. sports and computer geeks).

The first group chose 1920x1080i at 29.97, 25 or 23.976 interlace* frame rates. The second group chose 1280x720p at 59.94 or 50 progressive frame rates. Bit rates are similar for both groups. Compressor choice determines system bit rate. Today MPeg2 based systems use 15-25Mb/s for HD, MPeg4 AVC (h.264 and VC-1) based systems are looking to 6-12Mb/s at similar quality.


* 24 fps progressive film frames can be reconstructed from a 1080i stream.