10 dropped frames = 0 or >10 dropped frames?

BiT · 1st June 2003, 03:12

Hi

First of all, let me state the hardware and software I use:

CPU: PIII 550MHz
OS: Win2k SP3
Cap.card: Terratec Cinergy 600 TV
Cap.drive: 80gb ATA100 7200rpm Seagate Barracuda IV with 2mb cache on its own controller (a Highpoint ATA66/100/133 IDE controller (PCI))
Video cap. codec: huffyuv

I usually capture at 480x576, using Terratec's own capture software (can't seem to get vdub to work with this card). Then I filter it using VirtualDub.

Anyways, every time I capture, I get dropped frames (which I'm fine with, cause they're not that many).

The thing is, it seems to follow a pattern: the 1st frame is dropped around the 4900th frame, after that it drops 1 frame on a ~10000 frame interval (~14000, ~24000, ~34000 etc etc). It's the same every time I capture.

So, for a 1 hour capture, I have about 9 or 10 dropped frames. These are not noticable in the final video, so I never thought much about it.

...Until the other day, when I decided to try capturing at 704x576. There was the same "frame-dropping pattern" as before, so I figured "Hey, I can capture at 704x576. Great

". CPU usage was actually LOWER than when capturing at 480x576.

Later on, I was fiddling with it in VDub, and for some reason, I selected "Next drop frame" on the Edit menu -- and discovered that even though only 10 frames (out of ~100 000) were dropped, there were a LOT more frames marked D (dropped).

I found this quite odd, so I captured about 1 hour at 480x576, and as usual (same pattern), 10 frames were dropped. I then opened it in VDub, and selected "Next drop frame" -- and to my surprise, even though 10 frames were dropped, NO frames were marked as dropped.

Has anyone else experienced this?

Can anyone explain how 10 dropped frames in a 480x576 capture can be 0 dropped frames, and 10 dropped frames in a 704x576 capture can be MORE than 10 dropped frames?

Edit: I should add that for the 704x576 capture, dropped frames are noticeable in the final video. However, besides that, the overall quality is SO much better than when captured at 480x576, which is why I would like to fix this. Any suggestions at all would be much appreciated

Kind regards
BiT

killingspree · 1st June 2003, 10:37

hi,

1) i doubt you will be able to capture at full resolution with your processor.

2) to me it seems that the 'frame drop' counter in your capture app has some problem/bug. judging from your CPU you should have tons of dropped frames when capturing full res. as you said you dropped so much frames that you noticed it. therefore the actual amount of dropped frames is surely several hundred, much more likely in the thousands.

3) to sum up, i guess it would be smarter for you to capture at 480x576, but of course that is solely your decision

steVe
PS: no idea about this 'pattern', seems to me more like a capture app bug!

BiT · 1st June 2003, 11:20

Hi, and thanks for your reply

Indeed, it could be some sort of bug.

Terratec's capture app reported 10 dropped frames for both the 704x576 and the 480x576 capture. Both captures were roughly 1 hour long.

In VirtualDub, the 480x576 capture has 0 frames marked as dropped, and the listed fps is 24.999 (audio durations: 25.003).

As for the 704x576, there are 217 frames marked as dropped (1 every ~400th frame), and the listed fps is 24.999 (audio durations: 25.001)

Still, I actually do think the CPU's speed should be enough for full res captures, as CPU usage is quite steady (around 70-80%) when capturing at 704x576. And as I said, when capturing at 480x576, CPU usage is actually a bit higher.

Anyways, thanks again for your reply

Kind regards
BiT

1st June 2003, 03:12	#1 \| Link
BiT Registered User Join Date: Oct 2002 Posts: 4	10 dropped frames = 0 or >10 dropped frames? Hi First of all, let me state the hardware and software I use: CPU: PIII 550MHz OS: Win2k SP3 Cap.card: Terratec Cinergy 600 TV Cap.drive: 80gb ATA100 7200rpm Seagate Barracuda IV with 2mb cache on its own controller (a Highpoint ATA66/100/133 IDE controller (PCI)) Video cap. codec: huffyuv I usually capture at 480x576, using Terratec's own capture software (can't seem to get vdub to work with this card). Then I filter it using VirtualDub. Anyways, every time I capture, I get dropped frames (which I'm fine with, cause they're not that many). The thing is, it seems to follow a pattern: the 1st frame is dropped around the 4900th frame, after that it drops 1 frame on a ~10000 frame interval (~14000, ~24000, ~34000 etc etc). It's the same every time I capture. So, for a 1 hour capture, I have about 9 or 10 dropped frames. These are not noticable in the final video, so I never thought much about it. ...Until the other day, when I decided to try capturing at 704x576. There was the same "frame-dropping pattern" as before, so I figured "Hey, I can capture at 704x576. Great ". CPU usage was actually LOWER than when capturing at 480x576. Later on, I was fiddling with it in VDub, and for some reason, I selected "Next drop frame" on the Edit menu -- and discovered that even though only 10 frames (out of ~100 000) were dropped, there were a LOT more frames marked D (dropped). I found this quite odd, so I captured about 1 hour at 480x576, and as usual (same pattern), 10 frames were dropped. I then opened it in VDub, and selected "Next drop frame" -- and to my surprise, even though 10 frames were dropped, NO frames were marked as dropped. Has anyone else experienced this? Can anyone explain how 10 dropped frames in a 480x576 capture can be 0 dropped frames, and 10 dropped frames in a 704x576 capture can be MORE than 10 dropped frames? Edit: I should add that for the 704x576 capture, dropped frames are noticeable in the final video. However, besides that, the overall quality is SO much better than when captured at 480x576, which is why I would like to fix this. Any suggestions at all would be much appreciated Kind regards BiT Last edited by BiT; 1st June 2003 at 10:20.

1st June 2003, 10:37	#2 \| Link
killingspree Newbie Forum Mod Join Date: Aug 2002 Location: way too deep in (cyber)space Posts: 2,436	hi, 1) i doubt you will be able to capture at full resolution with your processor. 2) to me it seems that the 'frame drop' counter in your capture app has some problem/bug. judging from your CPU you should have tons of dropped frames when capturing full res. as you said you dropped so much frames that you noticed it. therefore the actual amount of dropped frames is surely several hundred, much more likely in the thousands. 3) to sum up, i guess it would be smarter for you to capture at 480x576, but of course that is solely your decision steVe PS: no idea about this 'pattern', seems to me more like a capture app bug! __________________ Search the forum, read the forum rules once more and use the search function on doom9.org before posting! oh btw my amazon.de wishlist

1st June 2003, 11:20	#3 \| Link
BiT Registered User Join Date: Oct 2002 Posts: 4	Hi, and thanks for your reply Indeed, it could be some sort of bug. Terratec's capture app reported 10 dropped frames for both the 704x576 and the 480x576 capture. Both captures were roughly 1 hour long. In VirtualDub, the 480x576 capture has 0 frames marked as dropped, and the listed fps is 24.999 (audio durations: 25.003). As for the 704x576, there are 217 frames marked as dropped (1 every ~400th frame), and the listed fps is 24.999 (audio durations: 25.001) Still, I actually do think the CPU's speed should be enough for full res captures, as CPU usage is quite steady (around 70-80%) when capturing at 704x576. And as I said, when capturing at 480x576, CPU usage is actually a bit higher. Anyways, thanks again for your reply Kind regards BiT