Interlaced.... or not?

[pgoelz]

Hi all,

I have a couple rather basic questions but I'm finding the correct answers a bit elusive. I am capturing old camera-original VHS videos (sometimes SP but usually LP) for archiving and potential restoration. I am using a Panasonic AG-1970 through a Prime Image TBC and an ADVC-55. Processing is done in Vegas Pro. Rendering to either MPEG2 at 6Mb/S or Sony AVC (h.264 at 4Mb/S)

I am having a terrible time getting the final product (or even the captured DV-AVI file) to look as good as it does straight off the recorder and through a TBC on my analog monitor (a Magnavox LCD TV/monitor that looks very good). It always seems a bit soft compared to the original. It occurred to me today that while I have been treating these captures as interlaced, they might be progressive (the ADVC manual is not specific). So as an experiment I reset the Vegas project to progressive scan (and disabled de-interlacing) and it looks noticeably sharper. These are old vidicon recordings in low light there is a lot of blurring that masks potential interlace effects. When the project is set to progressive I THINK I see interlace effects, indicating the output of the ADVC-55 is interlaced, same as the source.

I also discovered that the captured AVI file reports as 720X480 but Vegas was defaulting to 640X480. After I reset it to 720X480, it might look a bit sharper. Hard to say.

So..... what IS the output from the ADVC-55? I am assuming it is interlaced, same as the source. So the most optimum project settings in Vegas would be 720X480, lower field first. For de-interlacing, I had been using "blend fields". I just discovered that "interpolate" looks a tiny bit sharper. Tiny steps.....

I have played the raw DV-AVI file straight from the ADVC-55 and it doesn't look as sharp as the analog original. Any suggestions re: any way to optimise it? I don't think so since there are no options to be set. The difference is subtle but I am pretty sure it is real. Or is it that my analog monitor just happens to do a really good job with analog video?

TIA,
Paul

[edDV]

The ADVC-55 outputs DV format which is 720x480 interlace lower field first. For Vegas you should be using the "DV NTSC" default setting which is 720x480 lower field first. Set Deinterlacing Method to "interpolate fields".

If you were getting 640x480, some of your Vegas settings were wrong. Use the DV project preset.

When it comes to encoding you should stick with 720x480 interlace lower field first. Your MPeg2 bit rate is too low, this is the main reason for the quality drop. The TBC will cause some loss as well. For camcorder VHS source, you should be using CBR 9500 Kbps (highest quality) for video and 224 Kb/s for AC3 or mp2 audio.

For AVC h.264 export, you have several choices depending on the target player (e.g. media player, hand held device, internet uplink, etc). Some targets require deinterlace, others would do better with interlace.

[edDV]

I have played the raw DV-AVI file straight from the ADVC-55 and it doesn't look as sharp as the analog original. Any suggestions re: any way to optimise it? I don't think so since there are no options to be set. The difference is subtle but I am pretty sure it is real. Or is it that my analog monitor just happens to do a really good job with analog video?

How are you playing the DV-AVI capture file? I suggest you play with MPCHC or VLC with YADIF deinterlace set. Interlace video will never look as good on a PC monitor. The real test is to burn an interlace DVD and play that back to the same TV. If you set the DVD player to output interlace, then you have an apples to apples 480i comparison at the TV input.

[jagabo]

I recommend you view your DV AVI file with a program that shows you the frames without any processing (deinterlacing). Then you'll know exactly what you have. VirtualDub is good for this.

[pgoelz]

Thanks for the suggestions.

1. Yes, the Vegas defaults were wrong. I am now using the correct settings. Lower field first and interpolate.

2. I started this capture project a while ago outputting to MPEG2 so I could upload to YouTube or put them on DVD without re-encoding. But recently I noticed that rendering to AVC goes at least twice as fast when using NeatVideo so I've been using AVC and accepting a re-encode in the rare occasion that I need to make a DVD. The farther down the road I get on this project the more recent the videos are and the better they look off the recorder. I've been omitting NeatVideo with OK results, so the encoding speed is less of an issue.

3. Are you sure that 6Mb/S is too low for MPEG2 from VHS source? I haven't done careful analysis but it seems adequate so far. The originals do NOT represent the best you can get from VHS.

4. Re: the target for h.264 renders..... basically, YouTube. Possibly PC playback. Occasionally a DVD. I figure better to de-interlace it and stay progressive after the edited version is rendered. ?? That way I have control over the de-interlace. ??

5. Good point about what I am playing the raw (and edited) AVI files on. Vegas won't always play back at full resolution so I play back in Media Player. Perhaps not the best choice for interlaced content (the raw AVI file)? Never considered that. I'm using Windows 7 and do not have additional codecs installed. Maybe I should load ffdshow and try the various MPEG2 and DV-AVI de-interlace options?

6. I assume the Prime Image Freeze II outputs interlaced even though it acts on the full frame?

Bottom line is my LCD analog monitor still seems to look better than playing back the captured video. One thing I can try is to freeze a frame with the TBC, record that as video, and then look at it raw as well as rendered by Vegas. If nothing else it should allow more careful analysis since it will be static. As long as I don't use NeatVideo (which does temporal filtering that might not work well on a single frozen frame), that should work.

Paul

[jagabo]

For DVD you should keep your video interlaced. Otherwise you are losing half the temporal and spacial resolution. For upload to Youtube (or wherever) you need to deinterlace. There are much better deinterlacers than those provided by Vegas. I don't know if you want to go to the trouble of learning AviSynth though.

Don't judge your video by Vegas' preview. I believe Vegas displays DV without the usual rec.601 contrast enhancement. That will leave your video looking washed out. And again, it uses a poor deinterlacing technique. Make an interlaced DVD and watch it on your TV.

6 MB/s is generally sufficient for VHS to DVD transfers. But VHS is very noisy so it requires more bitrate than a clean film transfer or off air recording. So 9 Mb/s will look a little better.

[pgoelz]

OK, some things are becoming clear(er). But I need some clarification on the "rules" with Vegas.... I'm not entirely sure I understand the difference between the project settings and the encoder settings.

Do I always set the Vegas project settings to match the source..... except for the deinterlace method?

Example 1. I have interlaced source and I want interlaced MPEG2 for DVD use. I assume I set the project settings to lower field first. What about the de-interlace method.... set it to none? And ditto for the MPEG2 encoder... set it to lower field first?

Example 2. I have interlaced source and I want progressive output. I assume I set the project settings to lower field first and the deinterlace method to interpolate, right? What about the MPEG2 encoder? Do the project settings (set to deinterlace) present progressive video to the encoder so it should be set to "none - progressive"?

I feel like I'm over-thinking this, but I'm having trouble boiling all these choices down to basic rules.

And it is sounding like I will need to render separately for YouTube and for DVD. What does DVD architect do when asked to put progressive video on a DVD? Does it put it on as progressive?

Thanks for the help. As usual I thought I had the answers for a while. Then I realized I didn't. Not a good thing with about 100 YouTube uploads so far. I'm now slowly getting a grip on things. Oh, and you mentioned the bit rate needing to be higher for noisy VHS. It never occurred to me that low frequency chroma noise might be accentuated instead of masked by a low bit rate. But I do notice that there is usually more chroma noise in the rendered file than in the original. I'll have to try a higher bit rate.

Paul

[pgoelz]

Oh, I forgot to mention... Vegas does allow you to deinterlace for monitoring. It also can expand studio RGB out to 0-255 for the external monitor. Of course I had both set wrong.

Paul

[themaster1]

Don't use the deinterlacing filter in Vegas it's an advice. What's best is to use avisynth scripts and import them in vegas with the utility avs2avi. In avisynth use QTGMC to deinterlace it's simple to use and the best really.

[pgoelz]

So in other words, capture normally to an AVI file, then de-interlace with AVISynth to a new progressive file before editing that progressive file in Vegas? Makes sense except that it means double archiving if I want to keep both interlaced and de-interlaced versions. Are there any better de-interlacing plugins for Vegas? That way I would not have to deal with a second deinterlaced file. Not sure I understand the part about importing.... does that utility allow Vegas to perform the deinterlace using the script? I'll look it up.

My captures are going much better today. I think part of the problem was that I had been deinterlacing in Vegas with blend instead of interpolate AND rendering with Sony AVC set for interlaced video instead of progressive. I believe that in addition to the inferior blend deinterlace, that also cut my vertical resolution in half, right?

Thanks a million for the advice. It helped enormously to get my head around the process and separate out the settings that match the input from those that affect the output.

Paul

[edDV]

So in other words, capture normally to an AVI file, then de-interlace with AVISynth to a new progressive file before editing that progressive file in Vegas? Makes sense except that it means double archiving if I want to keep both interlaced and de-interlaced versions. Are there any better de-interlacing plugins for Vegas? That way I would not have to deal with a second deinterlaced file. Not sure I understand the part about importing.... does that utility allow Vegas to perform the deinterlace using the script? I'll look it up.

My captures are going much better today. I think part of the problem was that I had been deinterlacing in Vegas with blend instead of interpolate AND rendering with Sony AVC set for interlaced video instead of progressive. I believe that in addition to the inferior blend deinterlace, that also cut my vertical resolution in half, right?

Thanks a million for the advice. It helped enormously to get my head around the process and separate out the settings that match the input from those that affect the output.

Paul

Back to goals. You can't do one encode that optimizes for both DVD-HDTV display and Youtube. I'm assuming you want the best quality result for TV display right? Or will you accept poor TV quality with an optimized YouTube file?

The method I suggested gets you an optimized DV format edit master and DVD MPeg2 encode. Quick review:

1. Capture from Canopus ADVC to DV-AVI (Use WinDV or Vegas capture utility)
2. Set Vegas new project to "DV-AVI" (DV, 720x480, lower field first)
3. Edit with Vegas. Don't make quality judgments from the Vegas monitor. Make test MPeg2 DVD encodes and judge quality from DVD playback to TV*. Compare quality to direct VHS or captured DV-AVI file.
4. Export DV-AVI as your edit master archive file. You may want to apply different filters later for different encodes.
5. Encode DVD-MPeg2 720x480i 29.97 fps lower field first. Bit rate sets quality.
___ Use 9500 Kbps CBR to max quality. VHS is extremely noisy and needs bitrate**
___ Use default 6000 Kbps VBR for medium-low quality but for longer record times per DVD (97min vs 62min)
6. Test DVD playback to HDTV. Compare to original.

Next you go back to your DV-AVI edit master file to optimize an encode for YouTube. You can use Vegas to do the next steps or better do this with AviSynth filters.

Vegas method:
1. Set a 'NTSC DV" project. Set deinterlace method to "Interpolate fields".
2. Import your edit master DV-AVI file.
3. Optional - apply noise reduction or other enhancement filters (Sony or plug-ins). Noise reduction will reduce compression artifacts later.
4. Render as: Sony AVC 640x480 29.97 fps, progressive. Bit rate should increased until You-Tube max file size is approached. In other words, bit rate will vary by the length of the clip. You do this because YouTube will re-encode again to their standard. The more bit rate you give them, the better the re-encode quality.



Vegas will deinterlace using your "interpolate fields" setting in project. This usually gives better motion performance vs "blend fields" at the cost of slight blur to the clip. There are better noise reduction and deinterlace filters available for AviSynth but Vegas will give good results.


* Vegas has realtime DV export monitoring capability. If you had the ADVC-100/110/300 you could monitor the timeline live to your TV and make realtime quality assessment. The ADVC 55 lacks the DV to S-Video return feature.

** VHS is very noisy so requires high bit rate to minimize MPeg artifacts. Camcorder VHS is a worst case because of shaky camera handling and poor low light performance. Various noise reduction techniques will allow lower bit rates to be used. Still unless a tripod was used, shaky video will compress poorly.

[pgoelz]

Thanks, that makes sense. And is basically what I am now doing, although I am not encoding for DVD at present. Every once in a while someone asks me for a DVD of one or two YouTube uploads and until now I have just been using the YouTube render and accepting the quality hit. This also preserves the original captured AVI file for archival purposes.... I don't upload the entire capture, just highlights.

But you hit the nail on the head where playback quality is concerned. The problem was that I was variously deinterlacing twice and/or viewing deinterlaced when it was progressive. Got that straightened out now. On to find a better deinterlace. I tried the Smart Deinterlace plugin and it resulted in sine wave wigglies (much coarser than the line to line issues with bad deinterlace) in moving vertical lines so I abandoned it. Not sure I'm ready for AVISynth yet

Yes, my camera originals can often be the worst of the worst although I did often use a fluid damped tripod. For the first year, I was using an old two piece JVC two tube camera that was lucky to produce 20IRE in the lighting situations I was shooting in. Manual zoom and focus. Darker areas went full monochrome. After that I used an RCA with electric zoom that was better in low light but still rarely hit 100IRE. Couple that with LP speed (expensive tape in the early 80s) and I'm starting way behind the curve before I even capture it.

Yes, I see the folly of my ways... I should have opted for the ADVC-110 but I was trying to be cheap and didn't see the need for analog output.

Paul

[poisondeathray]

You should keep your original project and project files. It should be left as interlaced. This allows you to go to DVD without the generation losses. When you need a progressive export, deinterlace on export

There are large differences in quality between deinterlacers; all the best ones are avisynth based.

If you want to see an older comparison, download this file (right click and save)
https://forum.videohelp.com/images/guides/p1934885/stockholma_0-520_q3_yadif_mvbobmod_t...mca4_tdtmm.avi

Vegas with "interpolate" just resizes the fields with bicubic resizer, as a result you're left with aliasing and jaggy edges, these result in "shimmering" artifacts. In that video above, interpolate would look similar to yadif. Those aliasing artifacts require a lot more bitrate to encode. This is especially important for youtube, which re-encodes everything at a low bitrate

Even the most pristine VHS capture will have noise and can benefit substantially by cleaning it up and filtering it - again especially for youtube, because of the low bitrate

[pgoelz]

Yes, I definitely keep all raw AVI captures, Vegas project files and renders. I have close to 40 VHS tapes with 80+ hours of old folk music video shot in the early to mid 80s and this project started out as a simple archiving effort. I branched out into YouTube uploads later. I even back them up! Good thing hard drives are cheap

Out of curiosity, why are all the best deinterlacers implimented as AVISynth scripts? Why can't similar processing be done in a Vegas plugin?

Ya know, I am tempted to leave the video interlaced all the way to YouTube. The older recordings have enough motion blur just from the low light characteristics of the vidicon that interlace artifacts are not as visible as you would think. And there is a subtle but definite increase in sharpness.

Oh, and I de-noise all the noisier captures using NeatVideo. But I omit that step where possible because it takes so much longer to render.

Paul

[poisondeathray]

Out of curiosity, why are all the best deinterlacers implimented as AVISynth scripts? Why can't similar processing be done in a Vegas plugin?

I suppose someone could program a plugin, but no one has...

Deinterlacing isn't very good with other editors either: FCP, Premiere Pro, Avid MC, they all produce similar low quality results. Interlaced material is meant to be kept interlaced.

Even 3rd party deinterlacing plugins e.g. revision fx, red giant magic bullet frames, jes deinterlacer on a mac, etc... produce markedly worse results than QTGMC

[pgoelz]

Well, I had a go at AVSynth. Um..... life is too short While I can easily understand the power of that tool, I may just wait until someone ports it over to a GUI.

I got AVISynth installed along with QTGMC and all its required plugins. I made a script per the example in the QTGMC documentation and after some trial and error figured out how to specify my input file (that REALLY needs to be a GUI). Or at least I THINK I figured it out..... the script and the source file are in the same folder so I omitted the full path in the script.

I ran the script by opening it with Media Player. And the script (as displayed in Media Player) complained that it "couldn't locate a decompressor for fourcc dvsd". Thud. I'm assuming that it doesn't understand whatever codec was used to make the source avi file, but what to do about it? It is stuff like this that just doesn't fly in my world. At least not for long. I remember DOS and I occasionally dabble in Linux. This is like a throwback to that style of computer operation.

I'm not really looking for help, just venting. Unless it is something real simple I may go back in a quiet moment and try to go forward. But for now my captures are looking good enough that I am not highly motivated

EDIT: Just discovered that for whatever reason, AVISynth broke WinDV. WinDV would start its process but would not open the GUI. No idea why. I uninstalled AVISynth and rebooted and all was normal again.

Paul

[jagabo]

I ran the script by opening it with Media Player. And the script (as displayed in Media Player) complained that it "couldn't locate a decompressor for fourcc dvsd".

I suppose you've given up on AviSynth but FYI: Windows has two video subsystems VFW and DirectShow. Some programs use one, some use the other. There are separate codecs for the two systems.

Assuming you used AviSource("filename.avi"), you need a VFW DV decoder. I recommend Cedocida. You could also switch to DirectShowSource("filename.avi"). Windows has a built in DirectShow DV decoder.

[pgoelz]

Yes, I gave up on AVISynth and uninstalled it when it broke WinDV. However, I might go back to it at some point. I would like to see if the deinterlace routine is worth the effort if nothing else. If I do I'll try substituting DirectShowSource.

Paul

[pgoelz]

I feel compelled to mention how grateful I am for your patience with my issues and questions. This is not always the case on the internet. It could easily have gone "OH NO, not THAT question again! Use the SEARCH!". Searching for these sorts of answers is not always easy when you are not how to word the question.

Just wanted to say that I noticed and appreciate it.

Paul

[themaster1]

no need of a gui you just need a good avs script editor like AVsp..it'll change your life

- For QTGMC settings above Fast use denoising so beware if you want to retain grain

- Never use directshowsource but rather avisource,mpeg2source etc..

example of script (work with AvsP)

Function TestFunction(int index) { return Select(index, "Placebo", "Very Slow", "Slower", "Slow", "Medium", "Fast", "Faster", "Very Fast", "Super Fast", "Ultra Fast", "Draft") } # For UserSlider QTGMC
Avisource("C:MyVideo.avi", fourCC="LAGS", pixel_type="YV12") # Better to specify the pixel type and fourcc, change according to your source file
AssumeTFF() # important to specify the field order (TFF or BFF)
# QTGMC: 0= Placebo 1= Very Slow 3=SLow etc....
#QTGMC(preset=Select([<"Preset", 0, 10, 6>], "Placebo", "Very Slow", "Slower", "Slow", "Medium", "Fast", "Faster", "Very Fast", "Super Fast", "Ultra Fast", "Draft"))
QTGMC(preset=TestFunction([<"Preset",0,10,3>]))
SelectEven() # For QTMGC / Add this line to keep original framerate, leave it out for smoother doubled framerate

[pgoelz]

A script editor? I'll have to give that a try. But first to find out why AVISynth broke WinDV. If I can't figure that out, I can't install it again Even after rebooting, WinDV would load its process (as viewed in task manager) but would stall before bringing up the GUI. Enosoft worked OK so it wasn't something to do with either of them being able to see my ADVC-55.

Paul

[pgoelz]

Sigh.... I thought I'd devote an hour to trying out AvspMod. I got real close....

I re-installed AVISynth, then tried running AvspMod. No go. I'm running Windows 7 x64, so I tried some compatibility settings. That allowed it to run (as administrator). I could open, edit and (sort of) preview the video. But when I tried writing to an AVI file, the program started writing to the disk and then crashed. This was using an input from DirectShowSource, since I apparently don't have a VFW AVI codec.

So I thought I'd install the recommended Cedocida. But the readme warned that it would replace my existing codec. Since I don't know for sure if I have one and if replacing it would break something else, I stopped. I've been through codec hell back on Vista, trying to get h.264 to work and don't fully understand installing and uninstalling codecs, so I am reluctant to do anything that I cannot easily back out of. If I decide to go forward, I'll run a system backup first, just in case.

What I saw of AvspMod looked good, and something that would make using AVISynth fairly simple and straightforward. But I think I'll save it for a rainy day. OK, it is raining today... but I'll save it for ANOTHER rainy day. I have a recording session this afternoon and I need to get ready and have a clear head. Well, as clear as possible...

Oh, in case you are wondering, this time around, after installing AVISynth, WinDV works fine. Go figure.

Thanks,
Paul

[themaster1]

I'm not familiar with Seven but istn't there a 32bits mode you can enable? Avsp has been developped for 32 bits systems to the best of my knowledge.
Also you better download the normal version i find the modded version very bugy:
official website for avsp: http://avisynth.org/qwerpoi/Download.html

[jagabo]

32 bit programs run in a separate environment under 64 bit Windows. 32 bit programs cannot access 64 bit codecs, and vice versa. Some 32 bit codecs (LAME ACM, for example) don't install properly in 64 bit Windows and require a special installation procedure.

[pgoelz]

I am running it in compatibility mode in a 64 bit environment. It runs OK but barfs when I try to output an AVI file. But not right away. There is a period of maybe 5-10 seconds where it seems to be working. And even after Windows reports that it has stopped working and I close it, it remains open and goes through the motions of finishing the file output.... the progress bar rapidly goes from near zero to 100% and then the process seems to end normally. I haven't tried to figure out why. The QTGMC script uses several other plugins... maybe one of those is not compatible with x64?

Paul

[poisondeathray]

what do you mean "output an AVI file" ? do you mean through avspmod using avs2avi ? this can be unstable, I would use vdub instead (i.e open the .avs in vdub once you're done script editing in avspmod, to encode to some AVI format)

[jagabo]

I can use QTGMC() with 32 bit AviSynth and 32 bit VirtualDub under 64 bit Windows 7.

[themaster1]

You don't make .avi with avsp you edit your script, save it as .avs, you can see a preview of your script by clicking on the button at the extreme left/bottom you can even play your script in a video player such as MPC-HC which is probably the only one that can do that (the script must not be resource intensive). If you want to import the script in Vegas you must install avs2avi and in AvSp go to tools > save using avs2avi which will make a pseudo .avi file (very small).
Vegas like RGB24 so add a line at the end of the script:
ConverttoRGB24(matrix="rec601",interlaced=false)
....assuming you deinterlace with QTGMC prior that


Or if you wanna encode in mpeg2 i suggest you use HC-enc (free) which accept .avs script directly or other possibility for x264 (HD) encodes is Mediacoder.

[poisondeathray]

tools > save using avs2avi which will make a pseudo .avi file (very small).

Interesting, in the version I'm using (2.1.1 and all the others before that) it encodes AVI , by bringing up the VFW compression menu like vdub's compression menu . So it encodes actual video (but some versions are unstable in my testing)

It's not like avs2avi 0.3 (the dummy avi wrapper)

[themaster1]

Alright, i got an older version...i'd stick by the mothodology i've explained anyhow regardless of the version used