Still Massive Frame Drops *groan*

[funsoul]

Hi all!

After a major h/w meltdown...am back. Now have a 40g primary and am using the Fastrack66 controller with a pair of ibm 27g eide drives. Sustained throughput is over 24meg/s.

Even with the improved throughput, am still dropping tons of frames. On an 8min capture, dropped 16 frames. Have installed Flying Dutchman's YUY-enabler and am capturing at 352x240, 29.970 fps, 44.1KHz stereo in uncompressed mode (for some reason the HuffYUV codec results in hyper-digitized blurry colors...can't make out any images whatsoever...but that's another issue). Am using avi-i/o for the capture. The Matrox PC/VCR Remote (as always) reports 0 dropped frames.

Any ideas what the issue is and what could possibly resolve this problem?

My system:
pIII 500eb
256meg ram
g400-tv
40g primary (avi-io is sitting on this drive)
2 27g eide drives w/fastrack66

Thanks in advance (once again) for any assistance!
-funsoul

[funsoul]

OK...seem to be narrowing it down... I love avi-io and would like to use it. It's ease of use is excellent but the frame drops are killing me.

Tried out virtualdub this morning. Was able to capture at 352x480, 29.97fps, 44.1KHz, uncompressed without a single frame drop.

The problem with virtualdub, though (besides the fact that it's pretty complicated) is that I can't do anything with avi's that are over 2,096meg and virtualdub just tries to create these monster-sized files that are impossible to work with (or even play for that matter). Avi-io was excellent at this as it created a series of files that size.

So the problem is avi-io for some reason. For ease of use and the filesize issue, would prefer to go with it over virtualdub (unless someone can help me figure it out) but need to resolve the frame drop issue before buying it.

Any suggestions?
Thanks!

[Eric VanHeest]

VirtualDub will make separate AVI files if you really want it to; in v1.4b, the option is "Enable Multisegment Capture" under the capture menu. It used to be called "Enable Spill System" in older versions. In "Capture Drives" ("Spill System Setup" in old versions), just point it to your capture drive letter (you don't need to specify multiple drives unless you want to to dump files on them when it runs out of space on the primary).

Sometimes it's more convenient to let VirtualDub make the gigantic OpenDML files, though, and do your pre-editing cropping, noise reduction, and miscellaneous filtering in VirtualDub itself, but it depends on what you do to your video after you capture it. Mostly what I do is just archive television programs and such, so I can do everything without leaving VirtualDub. If I needed to use a Premiere-ish program after capturing to do more complex things, I might try using VirtualDub's frameserver (I don't know how well that works for interactive stuff, though; I've only tried it with MPEG encoders and the like).

[funsoul]

Hi Eric!

Thanks for the tip.

Any clue as to why I get frame drops in avi-io, though?

[funsoul]

Hi again Eric,

OK...tried it out using version 1.4b. Under Capture, Enable Multisegment Capture is checked. Under Capture>Capture Drives have my raided eide selected.

When I choose Capture>CaptureVideo(compatibility mode), there are no frame drops at all but the filesizes go way over the limit. When I choose Capture>CaptureVideo, the files are segmented properly but I dropped 5 frames in just over 3 1/2 minutes.

Am I doing something wrong here? Frames per second are set to 29.970.

[Eric VanHeest]

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When I choose Capture>CaptureVideo(compatibility mode), there are no frame drops at all but the filesizes go way over the limit. When I choose Capture>CaptureVideo, the files are segmented properly but I dropped 5 frames in just over 3 1/2 minutes.
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I'm not absolutely certain that those dropped frames are actually being dropped (i.e. causing a replicated frame instead of good data). I've had the same thing happen (1 frame reported as dropped every 1000 or so), but when looking through the video file at around the area that the reported dropped frame occurred, I didn't see any duplicated frames; there was constant motion between every frame for several hundred frames (a frame may have been missing in the middle of it; it would be hard for me to find that, but a missing frame wouldn't be important anyhow, compared to duplicate frames). The interesting thing is that 1 frame per 1000 is precisely the difference between 30.00 and 29.97 frames per second. However, it doesn't matter if I pick 30.00 or 29.97; I still get the one drop per 1000. I haven't done anything extensive (like determine whether the total length of capture matches up with 29.97 or 30.00), but I do know that I've never seen any problems in the resulting video at all due to frame drops.

I don't completely understand how the capture process is working there, but I suspect that at some level, that 0.03 frame/sec loss is intentional on the part of VirtualDub to keep something straight. If I experiment with it any more, I'll let you know; perhaps someone else here will have some extra insight. I also suspect that AVI_IO may be doing the same thing, although I don't use AVI_IO for anything (don't feel like buying it since VirtualDub is free and does what I need).

[SteveR]

You don't mention the capture source... Some camcorder, VCR equipment runs at 30 rather than 29.97 fps.

[funsoul]

Hi Steve,

Am capturing from videotape.

Also...why can't premiere properly open the series of mulitsegment files that virtualdub creates (for example...one long scene of say 10g that ends up being 5 2g files)? Will MediaStudioPro6 do it?

[Eric VanHeest]

Are they exactly 2048 kBytes? I can fully believe Premiere might do something stupid with that precise size. I might try 2000 kBytes or so and verify, if that is the case.

Then again, I often can't get Premiere to do anything useful whatsoever, so I may be a bit biased.

[kefoo]

AVI_IO will drop frames to keep the video and audio in sync with each other. Most audio cards don't deliver exactly 44,100 samples per second, so the audio will go out of sync over time. I get the 1 frame in 1000 drop every time I capture. If I capture with PC-VCR, the audio goes noticibly out of sync after a few minutes. I'm not sure if VirtualDub does the same thing, but it could explain why it's happening with AVI_IO.

Kefoo

[funsoul]

Thanks kefoo & Eric,

The files were actually 1,901meg each. I generally have no problems with Premiere (the only exception is when trying to batch encode more than 10 clips or so...it dies after that saying silly stuff like disk full or ran out of file handles).

It seems to have more to do with how VirtualDub spills the clips. When I opened the 1st of the six 1.9g files, it opened the entire scene (all 6 clips as 1 scene).

The frame drops are really that. They show up in the clip as black frames and even though there are a relatively low number of them, they show up on the final video clip. Am hoping to get this resolved as it'd be nice to be able to cap something and not have to go through it frame by frame to edit out the drops.

As for soundcard, am using TurtleBeach's MontegoBay2+

Doesn't anyone here ever get captures with 0 frames dropped? Would love to know what they're doing.

Thanks again!

[Eric VanHeest]

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The frame drops are really that. They show up in the clip as black frames and even though there are a relatively low number of them, they show up on the final video clip. Am hoping to get this resolved as it'd be nice to be able to cap something and not have to go through it frame by frame to edit out the drops.
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Are they black when you look at the files in VirtualDub? I've never seen a black frame when capturing; I'd definitely have noticed that, and VirtualDub is reporting several dozen dropped frames in a typical hour long capture. I have never, however, tried opening up a file that I just captured into Premiere; I always use VirtualDub to edit the file (temporal cleaning and such) and write it out to a new file before it ever touches things like Premiere. VirtualDub may be editing those out for you, in which case that may be ideal.

I've never gotten zero frames dropped, not on four different machines with three different types of capture cards between them, namely the Marvel G400, WinTV, and WinTV Theater (the Theater has S-Video input, which is handy). I would also like to know how to avoid these dropped frames if they are actually showing up, though. I assume they have to be related to the 29.97 vs. 30.00 nonsense.

[Sillyname]

I really don't know if it would matter if you're getting dropped frames on a "unsupported" feature. It's just like with overclocking the RR-S. Some people could, some couldn't. Perhaps MATROX did not document or enable the YUY feature because it was not reliable in all instances.

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Deep is not the root word of depression.

[funsoul]

Hi Eric,

Do you watch your final movies in their entirety? Ever see any black/dropped frames?

Also...am finding the VirtualDub documentation pretty tough. Is there a thread somewhere around that describes the ultimate way to use it and the filters/settings/etc that people have found optimal? On your longer vids, you say you capture using VDub then editing and exporting from there before using Premiere...doesn't that result in additional loss of quality? (premiere appears to have trouble with files over 2gig so are you splitting your vid in vdub or compressing it so that it's under that size?)

Am not sure what temporal cleaning does or is...any place that you know of that has complete descriptions and instructions on how to use these things?

I know am asking TONS of questions but would love to make the best possible vcds!

Thanks once again for your assistance!
-funsoul

[Eric VanHeest]

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Do you watch your final movies in their entirety? Ever see any black/dropped frames?
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I have never seen a black frame in any video I have ever captured with VirtualDub. I don't always watch the final movies all of the way through (although I so sometimes), but I usually select a segment 3/4 of the way through the video and play that for about 2 minutes to verify that the audio and video are synchronized, and I have never seen a black frame.

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Also...am finding the VirtualDub documentation pretty tough. Is there a thread somewhere around that describes the ultimate way to use it and the filters/settings/etc that people have found optimal?
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I have a personal set of filters that I use for capturing from cable television at less-than-perfect quality (which the cable always is). I don't have the settings file with me at the moment (you can save the filter sets to .syl files and load them in to any video), but it's basically:

1. Smart De-interlacer (Graft's) - this is absolutely essential unless the final target is a television, which it isn't; I make video files for personal viewing on the computer, not the television (eight computers in the apartment, one television). Deinterlacing is also necessary if your final vertical resolution is not 480 (which it isn't, for me; I use all kinds of resolutions, trying to find which looks best for the size).

2. Cropping (added to whatever filter I decide to add next). Always remember to crop away rubbush, especially the lines as the bottom of the capture that are invariably present when capturing from VHS. Always remember to retain the same aspect ratio when cropping. If your source is 4:3 and you crop off 6 lines from the bottom, you should crop off 8 columns total from the sides (4 left and 4 right, or 7 left and 1 right, doesn't matter).

3. Temporal Cleaner (Casaburi's) - This is another essential filter. When I look at the videos I make now versus the ones I made before I knew about the cleaner, it makes me want to re-do the older ones. I continually fiddle with the settings on this filter trying to find optimal combinations, but what's turning up is that the optimal numbers are quite different for different videos (however, any settings are vastly better than not using this filter at all). If your source is not cable/broadcast, then this filter isn't as essential.

4. 2D cleaner or smoother (on a low setting). Sometimes this one helps; sometimes it just wastes time during the encoding; you have to try it with whatever video you're using.

5. Resize (precise bicubic or precise bilinear). VirtualDub's bicubic filter has a sharpening algorithm in it which is sometimes what I want and sometimes not. When I capture video from a noisy source such as VHS, I always use a reduction filter, down to at least 448x336, sometimes 384x288. If it's an extremely noisy source, I'll size it down to 320x240, but past that I don't bother to continue with the capture. Of course, if you are targetting something specific like VCD, you need to resize to exactly 352x240, or 352x480, or whatever VCD/SVCD is (I've never made one myself).

I personally leave all of the audio in the file as 44 kHz/stereo until I'm finished with the project, then I extract the video (with VirtualDub, File->Save WAV) and use Cool Edit for normalization and noise reduction (audio noise reduction can make a tremendous difference), then save back to WAV and use VirtualDub to stream the audio back into the video file.

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On your longer vids, you say you capture using VDub then editing and exporting from there before using Premiere...doesn't that result in additional loss of quality? (premiere appears to have trouble with files over 2gig so are you splitting your vid in vdub or compressing it so that it's under that size?)
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I don't use Premiere a whole lot; someone else may have more to offer on this subject. When I do fiddle with Premiere, it's only to edit small segments of the video, so I just save the entire filtered file from VirtualDub (to a giant HuffYUV file), then load that file into VirtualDub and clip those segments out and save them to separate files (this is not the most painless operation in VirtualDub, but it works; lots of re-opening the source video, though), use Premiere to edit the small clips, and then use VirtualDub to re-join the segments back into a giant file (this is all done with no recompression, or to HuffYUV compression only) and start the final compression process.

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Am not sure what temporal cleaning does or is...any place that you know of that has complete descriptions and instructions on how to use these things?
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Temporal cleaning is the process of removing "snow" type noise from video; a temporal cleaner looks at the small differences between several frames and smoothes them out (according to a threshold; otherwise you would ghosting effects). It's extremely effective (far more than just blurring individual frames without regard to time) when used properly. Jim Casaburi's filter is available at http://home.earthlink.net/~casaburi/download/index.html

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I know am asking TONS of questions but would love to make the best possible vcds!
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Also be prepared to spend half a day or more compressing your final video