I'm puzzled... datarate?

[Tsuby]

Hi everybody.

I am puzzled.

I have solved various hardware problems, but now everything "seems" to be working.

But I am afraid there's still something strange and this is really nagging at me!

I use Avi_IO or Virtualdub to capture.
OS is win2k SP3
Cpu is an Athlon 1.333 Ghz
512 Mb Pc100 ddr RAM
OS is on a 20Gb HD (Quantum)
and the drive I use for captures is a Maxtor 80Gb connected to an ATA 133 promise controller. The drive is udma 6 and is working fine.
I usually drop 1-5 frames out of 50000 capturing from vhs (through scart/composite video in).

My problem is... the files are way too small!!

I am capturing PAL videos using yuv2 and compressing with huffyuv. Datarate should be 19000 kb/s (or something like that).
I.e. 20 minutes video should be 22 Gb or more, isn't it?

But I only have 12-13 Gb at the most and the overall quality of the avi is not as good as I would expect (maybe that's my vcr).

I am quite a newbie at capturing so I don't really know what I am doing wrong (IF I am doing anything wrong), but under win98 my captured files were much bigger.

I also tried capturing with virtualdub, instead of Avi_IO and this is the summary I captured while capturing ( ). I did not lose any frame doing this.



I am afraid there might be a problem with the drivers: my brother used the matrox hd benchmark by mistake and the result is awful (especially with the 80Gb drive, but it's working perfectly while capturing). Could it be that the matrox drivers are preventing me from capturing right?

Maybe I just misunderstood everything, but I'd like to unserstand more about this and I did not find anything in the forum.

Thanks Erika

[Dr Mordrid]

Hi Erika,

This is the main advantage of HuffYUV: uncompressed video at half the usual bitrate.

The uncompressed YUY2 data rate is about 20 mb/s. When captured with HuffYUV as a codec this drops to about 10 mb/s, depending on the content.

What card are you using?

The reduced quality can be from losses in the VCR, iffy cabling or it could also be you have an incorrect frame size set in the capture drivers.

Dr. Mordrid

[Hulk]

huffyuv looks bad if you play it back natively. Don't worry though, it compresses very well to MPEG-2 via TMPGEnc and looks great, if your source is great that is!

[Tsuby]

Hi!

thanks for the help.

I am capturing using my Marvel G400.
Matrox Video Tools Version 2.02
Matrox PC-VCR Version 2.02
and the drivers are the w2k_539 + macrovision patch

I am almost sure that the bad video-in quality derives from using my sony vcr. It's not the best one I have, but it was handy and I hoped it would work. I'll try with the best I have tonight (panasonic). It also has a super-s video out, which could help. I heard the output is much better. I also have an original panasonic cable, should be better than my usual one.

However I was most of all worried about the size of the file, but if huffyuv compresses at about 50/60% of the original uncompressed file, then it's ok, since I get about 12/13 Gb for 20 minutes video ^_^.

I am much relieved now

I'll let you know about my next results.

I just bought a dvd writer, so I need to have good videos!

Thanks

Erika

[Dr Mordrid]

I've found the middle to upper end JVC SVHS decks fit my needs very nicely.

Dr. Mordrid

[Tsuby]

Hi,

I changed the vcr and I'm even more puzzled than I was before

I've spent this evening reading older posts and it seems that I have a problem with field order and interlacing.

This is how my frames look like:



It seems that I have no frame order at all. I have tried playing with the settings of the huffyuv codec (swap fields, RGB... everything), but I had no luck.

I guess I don't need to say that I never had such problems when I captured under win98.

Tmpgenc "says" my field order is A, but it ALWAYS was B before I moved to win2k.

Maybe I did something wrong when I installed the huffyuv codec? Is it there a "special" version for win2k?

I don't really know what to do. I don't feel like installing win 98 again, now that I have everything setup in win2k.

Any ideas?

Thanks

Erika

[Debbie]

Hi Erika,

What you have there is interlaceing. You will get that with full frame capture 704 x 576 for PAL.

Have a look here:

http://www.100fps.com/

If you intend to use the material for DVD, then just encode it to MPEG-2 as it is. If you require it for computer monitor viewing, then de-interlace it using VirtualDub.

Cordiali saluti,

Debbie

[Dr Mordrid]

Right.

This kind of artifacting in the editor is from the footage being interlaced, which is normal for TV viewing but shows these kinds of artifacts when played on a computer monitor which is non-interlaced.

In plain footage (no effects) ignore interlace artifacts in the editor if the footage is going to be played on a TV.

The only times you'd delace them would be if;

1. the footage will be played on a non-interlaced device

2. the clip will have a moving path graphic overlay running over it

3. if you're applying a speed change to a clip

4. if you reverse a clip you can either delace it or reverse its field order

Dr. Mordrid