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| sasha |
| Posted: Oct 26 2002, 03:31 AM |
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Unregistered
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Hi all,
Does someone have expirience with gl450+VirtualDub? I have at least two problems:
1) During capturing using matrox gl450 with Virtualdub I have dropped frames. It is not a problem. The problem is the capturing process (card, driver, virtualdub?) inserts new frames intead of dropped (probaly to adjust synchonization) and these inserted frames are not a repeating of the same frame but some frame from a few seconds of preceding video.
For example, here is sequential of frames
123456289...
Frame 2 is inserted between 6 and 8. It happens quite regularly, usually each 5 seconds. I made testing capture, and found this inserted "old" frame looks like, happens at the moment, when I see a message in the status line about dropped frame. So i concluded, virtual dub(?), inserts a new frame instead of dropped one. Unfortunately, because inserted frame is completely different from its neighbours, it is very noticable. So I have to manually extract each such frame, using Adobe Premiere and this is a real nightmare
2) I can capure only without comression. I.e. I can capture, for example, avi 480x576 with no problem (except the above !), but only uncompressed. The dropped frame rate is relatively small: once in 5 sec. I could live with it. My setup is powerful enough to capture uncompressed (although it is inconvinient: >1GB/min of video). But as soon as I try to apply ANY comressor on ANY resolution, I have excessive CPU usage and a lot of dropped frame (> 50 %)
My setup:
Athlon 1600, 500MB RAM, disk RAID array (40MB/sec), W2K, Matrox gl450 with latest Matrox's driver.
I have a ton of tapes to convert to SVCD. Any idea would be very appreciated
Thank you
alexander |
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| Kippesoep |
| Posted: Oct 26 2002, 11:07 AM |
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Moderator of the Virtualdub support forum
Group: Moderators
Posts: 447
Member No.: 441
Joined: 6-October 02
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One dropped frame every 5 seconds is a bit much, IMHO. (I freak out when I have more than 1 dropped frame per hour  )
Things to try:
- disable overlay and preview
- set your source format to YUY2 or similar
- use HuffYuv
- make sure you have the latest drivers for your card
My system is much less powerful than yours, yet it can compress 768x576 at full framerate with only 58% CPU usage... |
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| sasha |
| Posted: Oct 26 2002, 05:15 PM |
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1) I use latest Matrox's drivers
2) disabling/enabling preview does not make a difference.
3) 5 second drop-out regularity looks like there should be a reson for it. I'm pretty sure, it is not occasionally, due to lack of real-time responce. It looks like, something accumulated and flushed every 5 sec out. For example, (i read somewhere), audio and video get to be synchronised. Actually, drop upts not a problem. But problem is how drop outs implemented - by replacing dropped frame with somewhat from "long time ago gone preceding video". So it looks like a flash every time.
4) cpu usage on capturing 480x576 25fps is ~10-20%. I tried full resolution, it works the same way(CPU of cource higher). So it is not a problem at all. But only if there is no compression. If I apply ANY compressor, including you mentioned, CPU usage jumps to 50%+ and drop outs >50%
5) Cannot use any other format then YUY2. On RGB, for example, the picture looks like has an inverted colors. I tried different parameters, but it always, the same, a sort of mscoding. The picture is there, but colors is totaly wrong
Thank you anyway
Does someone have specifical experience gl450+virtualdub?
alexander |
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| Kippesoep |
| Posted: Oct 26 2002, 10:42 PM |
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Moderator of the Virtualdub support forum
Group: Moderators
Posts: 447
Member No.: 441
Joined: 6-October 02
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This stuff seems to happen on WinNT/2K/XP. That's usually because of an unpleasant combination of the WDM driver and the WDM-VfW wrapper. Have you got the same problem under Win9x? You might also try AMCap (although the regular version doesn't allow you to use a compression codec) or any other DirectShow based capture program. Possibly the software included with your card. |
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| sasha |
| Posted: Nov 1 2002, 06:32 AM |
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Not sure I can use win9x. I have huge raid formatted for NTFS.
Found amcap on internet. Everything looks fine, except ... when I start to capture, on status line it reports 0 captured frames, although timer is incremented. AVI file, of course, is empty. This happens only if I capture in YUY2 format in any resolution. I can capture in any RGB format, but again, the resulting colors look miscoded it is complete mess up. Colors comletely wrong.
Format selection and video setting dialog boxes have title "MATROX VidCap"
So, this part works correctly, application recognizes driver and propose driver's settings. Preview works fine as well.
The matrox's software, unfortunately, affords capturing only in parial resolution. Full resolution is only compresed with noticable qualyty lose.
Vrtual dub at least can capture in full resolution, but with this problem (see my posts above)
Did I buy a wrong card ?
Any tip
Thank you
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| Kippesoep |
| Posted: Nov 1 2002, 08:49 AM |
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Moderator of the Virtualdub support forum
Group: Moderators
Posts: 447
Member No.: 441
Joined: 6-October 02
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What does the picture look like if you use RGB? Can you post a screenshot somewhere? |
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| sasha |
| Posted: Nov 7 2002, 05:51 AM |
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Unregistered
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After more accurate investigation I found I was not quite correct:
When Virtualdub drops frames, it duplicates and inserts frames instead of dropped.
Such behaviour is correct and normal. That what I expected.
But then I process AVI file using AVIsynth+Virtualdub, to deinterlace it. And on this stage instead of duplicated frames I have predeccesed frames from a few second before video, as I described in my first post
I use the next AVIsynth script to deinterlace
OpenDMLSource("f:\capture.avi")
SwapFields
Bob
SelectEven
the same incorrect way works
DirectShowSource("f:\capture.avi")
SwapFields
Bob
SelectEven
But another method to read AVI file is fine, and no problem
AVISource("f:\capture.avi")
SwapFields
Bob
SelectEven
Unfortunately, output AVI in the last case has no audio.
Has someone experienced this problem before ?
Or it looks like this is a question for a different forum ?
thank you
alexander |
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