VDub VHS Capture probs

[Bender]

Hi folks !

I'm trying to restore some old VHS recordings of mine using Virtual Dub and whatever encoder I can use (Actually I've recently tried the Indeo codec, as it's great for TV Captures to be later compressed to DivX in optimized settings).

Now, I have done everything I read in those countless How-To's on optimizing your sytem (no background tasks, manual settings of virtual RAM, and so on). For ordinary TV-Caps my system (Athlon XP 1800+, 256 DDR, Win98) works fine, even when compresing directly ot DivX, but not for VHS captures. There are loads of dropped frames, even though my CPU is bored (25-50% usage). What am I doing wrong ?
Does the messed up old VHS tape sabotage all enoding techniques or something ?
Can I tune some of those VDub parameters to cope with that (what the hell are those video buffers about) ?

And secondly, once I got the film on HDD, what's the best way to clean up that unsharp, blurred, whatevery image of my second copy of a copy of them old TV movie broadcasts ?

[techno]

use this: never use compression:

make sure DMA mode is enabled on your hdd.

biy a hauppauge wintv go pci capture card (dirt cheap but near DVD quality!)

then capture using these settings:

YUV2 or YU12 format
320-240/352*288
30.00 fps
CD QUALITY PCM AUDIO
NO RECOMPRESSION

and capture

now, file size will be huge but worth it.

you will get 10% dropped frames tops!

Everytime you capture something and use a compression codec, you WILL lose frames, no doubt, no recompression is not a compression codec, it captures it in true time.

You can also use AVI_IO as it drops less frames.

alternativly, capture :

directly to DIVX v3.22b (scene detect patch) and MP3 audio 44100Hz 128KBPS!

Techno

[benderman]

May be a problem with bad-quality tapes. There is a sync-signal that marks a new picture. Most TVs can handle a weak signal, but many capture-cards don't. Maybe it works if you use a better VHS-player or hardware-quality-enhancement that is connected between player and card. I don't know any software solution for that problem.

[jagarus]

Which of these video cards is better and why?:

http://www.compusa.com/products/product_info.asp?product_code=280217

http://www.compusa.com/products/product_info.asp?product_code=260799

http://www.compusa.com/products/product_info.asp?product_code=260803

[techno]

just don't go for ATI - I had bad experience - oh, awful. it was expensive and quality was so bad. go for hauppauge, Cheap and NEAR DVD or DVD quality!

Techno

[Apnoea]

I've had some problems with the VDub capture on my significantly lesser powered duron 750. realtime DivX compression at a mid resolution 358x276 (approx- i forget) works generally nicely, but I still get ~6% dropped frames, even with no compression.
Maybe dodgy video sync signal as Benderman says...
However, I get strange audio sync problems. The beginning will be in sync then gradually throughout the film it gets more and more out of sync. Frame rate alteration to match sync at the end of the file does not match the middle... non-linearity...

I'm thinking that the dropped frames (totalling more than 1 second) act cumulatively throughout the capture to de-sync audio & video.

So... Is there a way to avoid this? I was thinking forcing 1:1 interleaving and removing the 'additional' audio frames somehow later...? I suspect that VDub direct stream copy causes everything to fit nicely back into 1:1 interleaving with no double video or audio packets.

Cheers-
Apnoea

[Apnoea]

Just to clear things up....

I imagined that a dropped video frame would not cause the corresponding audio frame to be dropped.

This _may_ (pure speculation) cause 'double' audio packets in the subsequent avi which are ironed out by VDub direct stream copy, forcing 1:1 interleaving and hence a longer and delayed audio track than video track in the avi.

Clear as mud...

Apnoea

[techno]

correct.

use those settings I gave ya....see what happens, and remember...enable DMA mode on your hdd!

Quit any background apps too....install new motherboard and chipset drivers.

And then capture.

I always lose 10% of frames in ALL my captures - but then all fixed when I do my "special" encodings in TMPGENC then to fast motion.

Techno

[Apnoea]

I've been getting somewhat better results today from video.
Though my poor old cpu is 70-80% busy most of the time, I'm getting about 60 dropped frames per hour with:
20fps
352x288
DivX3.11 @500kbps
15bit RGB <------------- Is this particularly slow?
22khz 16bit Stereo --worth recording @44khz?
Would you seriously get noticably poorer quality from VHS @22khz?

Just a few queries though:

I've been using DivX 3.11a low motion
-Does bitrate affect performance?
I tried with 500 and 700- loads more dropped frames over the same portion of video. Purely one-off at the moment though.

Huffyuv 2.1.1- I downloaded & installed it but... Can't find it on capture in VDub. It's there in non-capture mode though.
I thought it was _supposed_ to be used for capture???

What's the 'special' encoding in TMPGENC? Can't say I've used it much.

Cheers
Apnoea

[techno]

what u just did us bad!

capture using NO RECOMPRESSION, or if necessory to capture using DIVX, use DIVX v3.22b

make sure audio is MP3 and video is DIVX 3.22b with 75 crisp and also 6000 bitrate

My "special" encoding is this:

when I capture using the settings I put up, I encode that into TMPGENC about 5-7 times...then to DIVX fast motion 6000 bitrate and 75 crisp.

it gives me NEAR dvd quality most of the time and also...I don't lose quality, I made a broadcast quality video once using this method and was put on DIVX-DIGEST.com but got put off cause the place I was hosting it, decided it was too good and put it off! So when my FTP is up, I will make sure people download it!

Use Ligos filters for MPEG2.......cause that's what I did and never once loosed quality...until 1 year ago where I had issued with Ligos filters...so I think I nearly solved that.

RE-ENCODING DOES NOT NECCESSARLY MEAN U R LOSING QUALITY!!!!!! - not the way I do it anyway!

Techno

[khp]

Originally posted by Apnoea
Huffyuv 2.1.1- I downloaded & installed it but... Can't find it on capture in VDub. It's there in non-capture mode though.

Make sure yo set Video format to YUY2 before selecting which codec to use, huffuy should be avaliable then.

[benderman]

RE-ENCODING DOES NECCESSARLY MEAN U R LOSING QUALITY!!!!!!

If you reencode a video it will be different from the original and that means loosing quality. There is actually no video-editor that adds details that haven't been there before (it's technicaly possible, but there actually is no programm that can do it).

BUT

Reencoding can give you smaller filesize without loosing too much quality if you use the right filters and codecs.

[Apnoea]

RE-ENCODING DOES NECCESSARLY MEAN U R LOSING QUALITY!!!!!!

Ah the joys of sampling theory!
Sample at or above the Nyquist frequency and you'd be theoretically OK... not taking into account codecs.

re: adding detail?
It's done in CT scans (ramp, hanning or optimised filters) which brings out the fine edge detail for 2d-image reconstruction.
Not really relevent to video though and the detail was there before, just enhanced.

But anyway......

Thanks khp- got huffy in there now

Only problem is I can't seem to capture more than 35ish minutes before the thing stops (avioutput error) at a filesize around 4gigs.
Splicing overlapping segments together isn't my favourite pasttime so I'm trying to use the 'spill' function - not reccomended with the one harddrive partition though...
Any ideas/tips?

Use Ligos filters for MPEG2.......

Eh? Is that for capture with MPEG2 or postcap filtering for divx too???? Never heard of ligos...

Cheers
Apnoea

[techno]

Ligos is an MPEG 2 filter...directshow filter playback..TMPGENC uses this property in order to encode and open MPEG2 files....

Techno

[khp]

Originally posted by Apnoea

Only problem is I can't seem to capture more than 35ish minutes before the thing stops (avioutput error) at a filesize around 4gigs.
Splicing overlapping segments together isn't my favourite pasttime so I'm trying to use the 'spill' function - not reccomended with the one harddrive partition though...
Any ideas/tips?

¨

You are probably using a FAT harddisk partition. If you are using win9x/me, there is nothing you can do about this. If you are using win2k/xp, you can reformat the partition as NTFS. Of course this will delete everything on that partition.