What is going on with Deinterlacing?!?!

[jieve]

Hello,

I have a deinterlacing/video player/format conversion question about which I am completely stumped. I have ripped my original Family Guy DVDs to my hard drive using DVDShrink (no compression) and DVD43. The idea was to convert to DivX and reburn to use for travelling on my portable DVD player, so I don't have to carry around boxes of the originals.

I have a number of video editing software programs on my comp but am mostly using Procoder 3 with DivX Pro 6.8.5. So I opened the main IFO file in Procoder, selected each episode, and started the conversion with the following settings: Source - 720x480, Interlaced, top field first. Target - 720x480, Interlaced, top field first. In the DivX codec I set 1500 kbps, balanced speed/quality, home theater and preserve interlace (top field first). I figured I'd keep it interlaced in case I watch them on my old TV. So I convert to DivX and they play fine. HOWEVER I've been trying to test different deinterlacing filters in VirtualDub and Procoder, and have been using Windows Media Player 11 to play back with the WinDVD 6.0 Xpack for viewing DVDs. I was using VLC 1.0.1, but I didn't like the DVD deinterlacing filters as much as the WinDVD one and found that there were some issues with DVD playback on my system, such as certain buttons in the dvd menus wouldn't line up, the colors were off, and I couldn't select some episodes.
Anyway here is the thing that's driving me crazy. When I play DVDs in windows media player with the windvd xpack, they are automatically deinterlaced and the playback is very smooth. I am assuming that the WinDVD plugin is responsible for this, and it seems to use a blend type deinterlace algorithm, there is definite ghosting upon motion, but it is clean and there are no interlacing artifacts. I would ideally like to recreate this deinterlacing scheme in a final progressive framed DivX version. Btw, the DVD output of the Family Guy DVDs is interlaced TFF, as verified by DGIndex and Procoder. Now, what I’ve found is that windows media player playback is not consistent, and I’m not sure what is causing this. It seems that sometimes when I open the converted DivX files in WMP, they are automatically deinterlaced, the method is not the same as with DVD, there’s no ghosting, more like a bob/weave combo type, but there are some jumpy artifacts, which I originally figured was from the DivX compression. Then I will close WMP, reopen it with the same file, and suddenly it plays completely interlaced with the typical interlace artifacts, but without the jumpiness, just as I encoded it. Why is it doing this?!?! I’ve noticed the same thing in the Procoder preview window. Is this an issue with the DivX codec? Obviously when you’re trying to compare different deinterlacing methods, you need the player to be consistent and to work properly. Any ideas?

Also, one other thing while I’m babbling here, I’ve tried all of the VirtualDub deinterlacing filters, and for this type of cartoon media, I’ve found by far the best method to be the ghosting/blend that the WinDVD plugin employs with WMP. I couldn’t get as clean images with the VirtualDub blend filter, there were still colored interlaced lines during motion, they just weren’t as frequent. It seems there were only half as many after applying the filter. Anyone have any reason why this was the case?

[jagabo]

VirtualDub doesn't handle interlaced YV12 sources correctly. You should try VirtualDubMod which does. Or use AviSynth (DgIndex, Mpeg2Source()) to open your MPG files and convert to YUY2 or RGB before VirtualDub:

Mpeg2Source("filename.d2v")
ConvertToYUY2(interlaced=true)

[poisondeathray]

IIRC, Family Guy R1 isn't straight forward. It's a mix of blends, and hybrid. When you encode straight to DivX as you have been doing, you're assuming a regular pattern, which might account for the jumpiness and inconsistencies

If you post a sample, I'm sure someone here could give you more info, and maybe suggest a script

I think there were a couple of threads here and on Doom9 dealing with Family Guy if you search

[jieve]

Thanks for the replies.

Yeah I noticed that family guy was a hard encoded blend of a number of different schemes, some scenes seem to be telecined with the 3,2 pattern, then suddenly the next scene has a different pattern, and these hard telecined, then interlaced on top of that. It seems to be all over the place, but the WinDVD decoder seems to deinterlace the DVD cleanly upon playback. However, regardless of the mix, the final product is interlaced tff according to DGIndex, otherwise the DVDs wouldn't play right on conventional interlaced TVs, at least I'm assuming this to be the case. I actually just played the interlaced DivX conversion on an old interlaced TV, and it played perfectly, as well as in my portable player, with no jumpiness of any kind. So standard deinterlacing should solve the problem on the computer monitor, I'm just wondering why I keep getting different results each time I play it with windows media player, as well as other players (VLC) for that matter. Eventually I'm going to want to probably deinterlace some of my DV footage, so being able to see what the original video actually looks like without unpredictable deinterlacing using random methods is important. I'll do a search for family guy. I'm not sure though that if I posted a short video it would show like it does on my comp, since I seem to be getting inconsistent results.

Jagabo, what exactly do you mean it doesn't handle them correctly? How does the color space relate to the interlacing? While I've been researching tons regarding digital video, transcoding, deinterlacing, etc. the color spaces/encoding methods are something that I haven't gone into too much depth with yet.

[poisondeathray]

However, regardless of the mix, the final product is interlaced tff according to DGIndex, otherwise the DVDs wouldn't play right on conventional interlaced TVs, at least I'm assuming this to be the case.

But DGIndex doesn't analyze the video and tell you what the actual content is. You have to do this manually. DGIndex is just reading the header, and it is often wrong.

If your goal is eventually to make a progressive DivX AVI as stated in your original post, I think the only semi-reliable way to do this is with an avs script with different filters, perhaps processing in segments

To farther investigate your WMP inconsistent playback, are you using DivX as the decoder? or some other like ffdshow? If you start a segment and skip forward a section (instead of starting at the same section), that might help explain your obersevations too

[jagabo]

You can perform a simple blend deinterlace (similar to VirtualDub's) in AviSynth with Blur():

Mpeg2Source("filename.d2v")
ConvertToYUY2(interlaced=true)
Blur(0, 1.0)

I like to follow that up with Sharpen(0, 0.7).

[lordsmurf]

Given the output viewing device, I think DEINTERLACE AREA-BASED filter in VirtualDub would be easy and fine to use. Try for quality, but let's not get OCD and overdo it. That is a quality method, it will work. Maybe not the best (or "perfect") for a large screen, but plenty perfect for anything normal sized or smaller.

[jieve]

Guys, thanks again for the informative responses.

<<<But DGIndex doesn't analyze the video and tell you what the actual content is. You have to do this manually. DGIndex is just reading the header, and it is often wrong.

If your goal is eventually to make a progressive DivX AVI as stated in your original post, I think the only semi-reliable way to do this is with an avs script with different filters, perhaps processing in segments

To farther investigate your WMP inconsistent playback, are you using DivX as the decoder? or some other like ffdshow? If you start a segment and skip forward a section (instead of starting at the same section), that might help explain your obersevations too>>>

You’re definitely right about this. I guess if I were severely OCD and forgot to take my medication I could probably go through segment by segment and try to correct every frame, but fortunately I’m not that much of a perfectionist. I actually just wanted to have compressed versions of the episodes that are deinterlaced and easy on the eyes, sorta the way they looked from the DVD in WMP. While you’re absolutely right that DGIndex is just reading the header and the actual footage could be completely different, with mixes of telecine patterns thrown in there for good measure, it definitely has been processed to 29.97 fps and interlaced for tv viewing.

About the codec, this is a good question. Is there any way I can find out which codec is being used? I was assuming the DivX decoder, but maybe it’s switching back and forth for some unknown reason, resulting in the mix of deinterlacing vs. not.




Lordsmurf, thanks for the recommendation. Actually, I just tried it out and this is almost exactly how WinDVD does it when playing the DVD in WMP. It is exactly what I was looking for for this type of footage. But I do notice that the color is off in the blend, for example, in Lois’s hair in the opening scene in one frame, there are two of her in two different positions (ghost), but there are blue stripes in her red hair from the background wall. Anyone know why this is? I figured the field lines would just be doubled in the motion areas and overlayed. Jagabo, was this maybe what you were talking about the YU12 issues?

[jagabo]

But I do notice that the color is off in the blend, for example, in Lois’s hair in the opening scene in one frame, there are two of her in two different positions (ghost), but there are blue stripes in her red hair from the background wall. Anyone know why this is? I figured the field lines would just be doubled in the motion areas and overlayed. Jagabo, was this maybe what you were talking about the YU12 issues?

Yes, that is from VirtualDub's incorrect handling of interlaced YV12.
https://forum.videohelp.com/topic369911.html#1983329
https://forum.videohelp.com/topic369911.html#1989163

I've seen TV broadcasts do this when upscaling or downscaling between HD and SD.

[jieve]

Awesome, thanks.

Ahhhh, yes now I remember why I wasn't working with virtualdubmod, it says it can't find corona.dll, and the link to the sourceforge website I found with the dll is broken. Any idea where I can get it?

[jagabo]

coronal.dll should be in the VirtualDubMod folder along with VirtualDubMod.exe. Here's a copy:

corona.zip

But I suspect you'll need something else too.

[jieve]

Of course you were right about needing more. The only things in the virtualdubmod folder from my download are virtualdubmod and virtualdubmod.vdi. Now it's saying I need ogg.dll. Anywhere I can get all of these in one place?

Also, I'm trying to find out which codec windows media player is using for divx files, any ideas where I can find out? Alternating codecs seemed like a feasable possibility as to why it was deinterlacing sometimes and not other times.

[poisondeathray]

Also, I'm trying to find out which codec windows media player is using for divx files, any ideas where I can find out? Alternating codecs seemed like a feasable possibility as to why it was deinterlacing sometimes and not other times.

Render the file in graphstudio, this will tell you your current directshow decoder.

You can adjust the properties, switch filters , change merits etc...

If jieve is using DGIndex, (I'm assuming he's already using an avs script to open this in vdub, since he talked about DGIndex earlier), how can the color issues be the result of vdub's MPEG2 decoder?

[jagabo]

If jieve is using DGIndex, (I'm assuming he's already using an avs script to open this in vdub, since he talked about DGIndex earlier), how can the color issues be the result of vdub's MPEG2 decoder?

DgIndex outputs YV12. VirtualDub converts it incorrectly to RGB for filtering.

The MPEG2 decoder plugin for VirtualDub also outputs YV12 which VirtualDub then converts to RGB for filtering.

[jieve]

I only used DGIndex to check out the VOB info from these DVDs, I haven't used a script or anything to open it from VDub. The problem jagabo described with the chroma channels seems to be exactly the problem I'm having, having to do with the incorrect handling of them when interlaced.

[poisondeathray]

Thanks jagabo, I read that other thread some good info there

If you do all your filtering in avisynth, using "fast recompress" this issue is avoided , correct? i.e. it's only if you use vdub in full processing mode (vdub incorrect conversion of interlaced YV12 to RGB) and vdub filters

[jieve]

Ugh, sorry to keep posting about these dlls, but looks like any trustworthy link is broken and most of the sites I'm coming across on google seem sketchy, according to other forums I'm gonna need

ogg.dll
msvcr70.dll
vorbis.dll

none of which came from the download from sourceforge.

[jagabo]

https://www.videohelp.com/download/VirtualDubMod_1_5_10_2_b2542.zip

[jagabo]

If you do all your filtering in avisynth, using "fast recompress" this issue is avoided , correct? i.e. it's only if you use vdub in full processing mode (vdub incorrect conversion of interlaced YV12 to RGB) and vdub filters

Yes, as long as your encoder handles interlaced YV12 correctly you'll be ok in Fast Recompress mode.

I mentioned this to Avery Lee a while back but his opinion was that the YV12 fourcc should never be used for interlaced YUV 4:2:0 video. So he refuses to compensate for it. Though he may be technically right, many codecs and programs output interlaced YUV 4:2:0 video with the fourcc YV12. Maybe in ten years or so he'll eventually come around like he finally did with VBR MP3.

[jieve]

Thank you! Now it's working fine with VirtualDubMod and that's the type of deinterlacing I've been looking for. Too bad I couldn't do that with procoder, there I can select the individual episodes instead of having to cut them out of the slew of VOB files.

[jagabo]

If you want really good deinterlacing you want to use TempGaussMC_beta1() in AviSynth.

[jieve]

All this talk about deinterlacing has gotten me to take a look back at my archived DV footage which I left interlaced, and motivating me to deinterlace them. Is there a way to do this without converting color spaces from DV 4:1:1? I'd like to deinterlace first, then import into premiere pro for possible editing.

Also, what do you guys think about Gunnar Thalin's Smooth Deinterlace with Virtualdubmod, and doubling the framerate to deinterlace? This seems like the best way to maintain temporal resolution, but can I keep it in DV format at 60 fps? Also, can this happen without changing color spaces since VDM works with RGB? I've read that site 100fps.com's deinterlacing article probably 10 times and the guy raves about it, but the site also seems a little dated.

[jagabo]

I wouldn't deinterlace unless you are posting clips to places like Youtube where interlaced video gets screwed up, or sending video to others where you can't control the playback (they may not have a deinterlacing player). Deinterlacing always degrades the picture quality.

VirtualDub converts everything to RGB for filtering. AviSynth can work in RGB, YUY2, or YV12. YUY2 is the closest match to DV 4:1:1.

From what I've seen Gunnar Thalin's Smooth Deinterlace leads to terrible bob bouncing. Here are some examples of deinterlacing algorithms in AviSynth:

https://forum.videohelp.com/images/guides/p1934885/stockholma_0-520_q3_yadif_mvbobmod_t...mca4_tdtmm.avi

Smooth Deinterlace is something like Yadif() or TDeint(). TempGuassMC_beta1() only works in YV12 but if you're going to MPEG 2 or MPEG 4 that's fine.

[jieve]

The clips are recordings that I've made travelling that I want to keep archived in the highest quality possible. They are currently in DV25 format taken directly off tape with no edits, and will not be compressed to MPEG2 or 4. Eventually as hard drive space gets larger and larger I will probably be able to resave them as uncompressed. While my initial inclination was not to touch them, they are and will be only ever watched on non-interlaced output devices (I don't see interlaced TVs making a comeback any time soon) so they are constantly deinterlaced upon playback anyway (or not, and I'm watching the artifacts). Obviously I have to face the fact that deinterlacing will reduce the quality, but if I can double the framerate and preserve as much information as possible with a good filter, I figured I may as well do it.

So in avisynth, I would convert to 4:2:2 and then run it through one of the deinterlacers? But not in the timeline otherwise it turns to RGB? Since the NTSC DV standard is 29.97fps interlaced, what would the output format be?

[jieve]

Wow yeah the TempGaussMC looks good. Is that double framerate?

[poisondeathray]

Yes that's double frame rate (bobber), but that sample video was actaully slowed down to 1/2 speed

Warning: TempGaussMC_beta1 is very, very CPU intensive (i.e. slow processing)

Yadifmod+nnedi2 gives similar results to TempGaussMC_beta1 (except it's a few times faster, and applies less blur, retains more detail), and can stay in YUY2

I'm not quite understanding your rationale for this? Are you wanting to make some deinterlaced copies just for view purposes on an LCD ? I would always keep the original DV-AVI archived for later projects

You seem very concerned about the quality losses during additional colorspace conversions, but in reality you will lose more during the lossy compression to your final format for viewing, than the colorspace conversion itself

[jagabo]

they are and will be only ever watched on non-interlaced output devices (I don't see interlaced TVs making a comeback any time soon) so they are constantly deinterlaced upon playback anyway (or not, and I'm watching the artifacts). Obviously I have to face the fact that deinterlacing will reduce the quality, but if I can double the framerate and preserve as much information as possible with a good filter, I figured I may as well do it.

But if you deinterlace and save now the artifacts you generate will be in the video forever. Whereas allowing the player or TV to deinterlace will lead to better deinterlacing with time (ie, software and TVs will get better at deinterlacing).

So in avisynth, I would convert to 4:2:2 and then run it through one of the deinterlacers? But not in the timeline otherwise it turns to RGB? Since the NTSC DV standard is 29.97fps interlaced, what would the output format be?

I'm not aware of any Directshow or VFW DV decoder that outputs YUV 4:1:1 video, any software that would accept it, or even a fourcc code that would indicate it. The DV decoder will output YUV 4:2:2 (usually YUY2) or RGB, whichever both the decoder and receiving software accepts.

For example, Panasonic DV codec only outputs RGB. Cedocida can output RGB, YUY2, or YV12. You can configure it to output only a specific color space or let it negotiate the best color space with the editor/player (usually YUY2).

[jieve]

Yeah, this is the question I always argue with myself, whether or not/how much to process video/photos/etc for archiving. For example, I scan an old photo family photo, it has a bad color cast. I do some touchups in photoshop, and the final version looks great. So do I delete the original, or keep it? With photos it's an easier decision since they don't take up tons of space uncompressed, but video of course is a different story. These videos are not going to be used professionally, they're only for myself, so do I edit them, keep the improved version and delete the original, or do I keep the original? I can never decide. I guess in 5-10 years with the move toward progressive video, better deinterlacers will come along. Hmmm, I guess it's something I'll have to think about a little more.

Hmmm, oh I see, the video comes off tape YCrCb 4:1:1 and stored on HD, is decoded to 4:2:2 or RGB by the codec. Sorry, I think my question may have been confusing, probably because I may not have a clear understanding of what's happening: I was assuming that since an NTSC DV formatted has certain characteristics ( 29.97fps, 4:1:1 YUV), that if I changed the color space and doubled the framerate that somehow it would no longer be DV-AVI, of course that doesn't seem to make sense... Sorry, this is probably a stupid question, but I've been reading so much about this lately that my head is reeling.

[poisondeathray]

Yep you're correct, it would no longer be DV-AVI, and passthough wouldn't work in Premiere for example, as you and EdDV were talking about in the other thread. 720x480 60p doesn't fall within DV-AVI standards

When you deinterlace or process with avisynth, you have to encode to some other format. The majority of end user formats for playback are YV12 4:2:0.

Your target playback device also may limit your decisions on what format you choose. Something like an HTPC would be leave you the most options, but if you were watching on a standard DVD player you have very limited options

I would keep the originals, but it's a decision you have to make weighing pros/cons. HD space is much more affordable these days. Personally I like to use non-destructive methods as long as possible in the workflow. So if I were to touch up some photos, I would save using adjustment layers and .psd format instead of .jpg. I hate losing quality, and try to minimize it at every stage even if it takes longer.

[jieve]

Poisondeathray, thanks for that. Good to see my thinking was in the right place. I am the same way, I hate losing quality so any conversion I do I tend to move toward uncompressed when compression is involved (photos, music, where space permits). However, archiving becomes a complicated topic since pretty much anytime you change major formats/technologies (analog to digital, for example), there is a loss of information, and it is impossible to predict what the future will hold. Who knows, maybe 30 years from now we'll be trying to convert our footage to 3D holographs or something. I've decided I'm definitely going to keep the originals and see what comes along technology-wise as time progresses, would be interesting to try out some of those deinterlacing filters though.