Dropped frames on different consoles

2004-12-22 01:19:45 am

I love YaBB 1G - SP1!

I've been playing around with video capture for a couple months now and have useed many different consoles. I was wondering if anyone has had experiences similar to what I have observed. I may be totally off base here, so just looking for some second opinions.

While capturing with virtualdub I always get dropped frames no matter what I do. Not a large amount but always at regular intervals. So I started doing various tests and found that the only variable was which console I was using. Here's what I got.

System used:

P4 3.2Ghz
ATI All in Wonder 9600 Pro
1 gig 400Mhz DDR ram
Capture drive: Maxtor 250gig SATA 16meg buffer
Sound card is moot since the tests are unaffected by sound off
Virtualdub Sync 1.5.4

These results are independent of:

-Sound quality: From 48khz stereo to sound off
-Capture resolution: 720x576 to 320x240
-With or without compression, same results
-Various virtualdub settings for buffers didn't change anything (used recommended settings)
-S-Video, composite video, even high quality S-Video cables (monster cable) didn't make a difference

The captures were made at 29.97fps

Gamecube: 1 dropped frame per 100 seconds exactly
Dreamcast: 1 dropped frame per 100 seconds exactly
Cable TV: 1 dropped frame per 100 seconds exactly
N64:1 every 17-17.5 seconds regularly+small extras for approx 7 drops per 100 seconds
SNES: 1 every 13 seconds regularly+extras for approx 11 drops per 100 seconds
NES: 1 every 13 seconds regularly+extras for approx 11-13 drops per 100 seconds, drops more erratic than
SNES

All videos come out with perfect audio sync even across long hours. When trying to capture a more or less fps the drops become worse. I've tried other programs which don't drop frames but they give crazy audio sych problems. In any case the audio doesn't affect the tests.

Now the capture from the cable TV is for all intents the perfect NTSC signal right? It gets the regular 1 frame per 100 seconds drop same as the modern consoles. Notice the trend when going to the older consoles, they drop a lot more frames. Could these dropped frames simply be because the consoles are giving all they can give? Is the older hardware simply not up to giving the full 29.97 fps?

Thread title:

I've been playing around with video capture for a couple months now and have useed many different consoles. I was wondering if anyone has had experiences similar to what I have observed. I may be totally off base here, so just looking for some second opinions.

While capturing with virtualdub I always get dropped frames no matter what I do. Not a large amount but always at regular intervals. So I started doing various tests and found that the only variable was which console I was using. Here's what I got.

System used:

P4 3.2Ghz
ATI All in Wonder 9600 Pro
1 gig 400Mhz DDR ram
Capture drive: Maxtor 250gig SATA 16meg buffer
Sound card is moot since the tests are unaffected by sound off
Virtualdub Sync 1.5.4

These results are independent of:

-Sound quality: From 48khz stereo to sound off
-Capture resolution: 720x576 to 320x240
-With or without compression, same results
-Various virtualdub settings for buffers didn't change anything (used recommended settings)
-S-Video, composite video, even high quality S-Video cables (monster cable) didn't make a difference

The captures were made at 29.97fps

Gamecube: 1 dropped frame per 100 seconds exactly
Dreamcast: 1 dropped frame per 100 seconds exactly
Cable TV: 1 dropped frame per 100 seconds exactly
N64:1 every 17-17.5 seconds regularly+small extras for approx 7 drops per 100 seconds
SNES: 1 every 13 seconds regularly+extras for approx 11 drops per 100 seconds
NES: 1 every 13 seconds regularly+extras for approx 11-13 drops per 100 seconds, drops more erratic than 
SNES

All videos come out with perfect audio sync even across long hours. When trying to capture a more or less fps the drops become worse. I've tried other programs which don't drop frames but they give crazy audio sych problems. In any case the audio doesn't affect the tests.

Now the capture from the cable TV is for all intents the perfect NTSC signal right? It gets the regular 1 frame per 100 seconds drop same as the modern consoles. Notice the trend when going to the older consoles, they drop a lot more frames. Could these dropped frames simply be because the consoles are giving all they can give? Is the older hardware simply not up to giving the full 29.97 fps?

marshmallow

2004-12-22 02:08:15 am

Jack of all Trades

Your experience mirrors mine. I figure, why worry?

The_Pro

2004-12-22 03:20:44 am

I love YaBB 1G - SP1!

That's exactly what I was looking for, thanks.

Radix

2004-12-22 07:50:08 am

I'm addicted to games

Yeah, be glad you dont drop 2-3 frames every second like me! Although the 1 per 100 being so consistent is pretty weird. I thought maybe it was because whe you tell vdub to capture at "29.97" fps it's not really capturing at 30000/1001 which is the official ntsc framerate. But the difference is so small it should take hours to appear.

The_Pro

2004-12-22 10:05:25 am

I love YaBB 1G - SP1!

I have no idea why either but the fact that this isn't an isolated issue makes me feel better. I would have been pissed to have bought a new system only to have sub par capturing. Now that that's cleared up, time for some speed runs!

2-3 drops per second? Time to jack up the DVD prices and get a new capture card ;).

marshmallow

2004-12-22 08:43:04 pm

Jack of all Trades

Yeah, on some of my longer runs (Like GE and BK) I had several thousand dropped frames. Maybe even 100K+, but it didn't seem to affect the final product any.

The_Pro

2004-12-29 12:53:06 am

I love YaBB 1G - SP1!

I've got some interesting developments going on here. Still working on it, but at this point I've been capturing my SNES for 70 minutes with 0 dropped frames. Stay tuned or something ;).

The_Pro

Edit history:

The_Pro: 2006-02-27 07:35:38 am

2004-12-29 09:13:13 am

I love YaBB 1G - SP1!

I was going to write this long thing about trends and duplicate vs dropped frames and such but the N64 is shooting my theories to hell. It's driving me crazy.

Radix

2004-12-29 09:25:58 am

I'm addicted to games

If the [s]nes are outputing MORE than 29.97 fps (even if it's just one extra frame every 100 seconds) then how were you dropping frames at 29.97 ... it should be MISSING frames not getting a frame where there's nothing (aka, a drop).

The_Pro

2004-12-29 10:33:22 am

I love YaBB 1G - SP1!

Well I just figured out ealier that virtualdub doesn't care if it's a duplicate frame or a missing frame, it refers to it as a drop. At 29.97 they weren't any duplicate frames, they were simply missing, something I hadn't verified at the time. Capturing at a higher rate let me get those back.

Initially I thought changing the frame rate made things worse because putting it to 31 would drops frames like mad. They were just a lot of duplicates, I had to go in smaller increments. The N64 though, all the drops seem to be duplicates, what a headache.

The_Pro

2004-12-29 10:53:17 am

I love YaBB 1G - SP1!

Hmmm, I'm starting to think my whole understanding of duplicate and dropped frames is whacked. That's what happens when you try to piece together theories when you clearly aren't qualified ;). In any case as long as my frames drops are at 0 I'm happy.

Can't seem to optimise the N64 as well though. Best I can do is make it stable at 1 drop per 10 seconds, can barely notice it. That's at 29.9994 fps, going lower throws it off and gives 3 drops at once every once in a while.

Oh, and even though the N64 doesn't bob, there's still some jittery crap on the top line, except for some games that are cropped (Waverace). Weird, a quick crop fixes that though.

Radix

2004-12-29 10:09:04 pm

I'm addicted to games

Quote:

Well I just figured out ealier that virtualdub doesn't care if it's a duplicate frame or a missing frame, it refers to it as a drop.

Hmm well what about in the final file? The duplicate frames should show up with [D] indicators. If at 29.97 you were only getting 'drops' that were missing, you should have no [D] frames in the final file...

The_Pro

2004-12-30 12:46:10 am

I love YaBB 1G - SP1!

Quote:

Hmm well what about in the final file? The duplicate frames should show up with [D] indicators. If at 29.97 you were only getting 'drops' that were missing, you should have no [D] frames in the final file...

Yep, that's exactly what was going on with the S/NES, no [D] frames at 29.97fps even though there were drops. Checking the animation, in this case mario's feet when running, there was indeed a frame missing in the animation. Originally I didn't check if it was missing or a duplicate because I assumed all drops were the same.

Radix

2004-12-30 08:08:21 am

I'm addicted to games

Wow

who'd have thought that vdub used the same measure to tell you two things.

Thanks a lot!