VideoHelp Forum




+ Reply to Thread
Results 1 to 7 of 7
  1. I am attempting to make VCD's from VHS using nanoDVR realtime MPEG1 capture. My system has the following spec:

    AMD Athlon XP1600
    ECS K7S5A motherboard (running 138MHz FSB)
    512MB DDR RAM
    40GB IBM 7,200rpm UDMA Mode-5 HDD
    NVidia GeForce2 MX 32MB
    WinTV PCI capture card
    Windows XP Professional

    The problem I am experiencing is that nanoDVR is dropping, on average, between 15% and 20% of frames during capture . However, more annoyingly , when the mpeg is played-back, the video 'jitters' at certain points. By 'jitters', I mean it appears to get 'caught' between frames for a moment before continuing. I assume this is directly related to the frame dropping problem. One thing worth mentioning is that the VHS recording I am capturing from is of pretty poor quality... I seem to remember that this will cause the MPEG1 CODEC to have a much higher CPU overhead(?)
    I shutdown all other apps when capturing and Task Manager shows the CPU overhead to be about 84% on average during capture. I know about the HuffYUV CODEC and TMPGEnc, etc, but I really want to encode in realtime if at all possible... it's much quicker less hassle and I don't need to always make sure I have several GB of HDD space set aside! Any help or advice you can give would be much appreciated!
    Quote Quote  
  2. First, my system is very close to yours:

    Athlon XP 1900+
    Asus A7V-133c
    768mb SDRAM
    40gb Maxtor 7,200 ATA 100
    GeForce 3 ti-200 128mb
    WinTV PCI
    Windows XP Pro

    I use Cyberlink PowerVCR whenever I want to capture to MPEG-1/MPEG-2 in realtime and don't have any problems. When capturing to VCD format it uses about 20% of my processor, however (and this is a topic of debate in these forums) I usually capture at a resolution of 720x480 @ 5000bps and then use Ulead Media Studio to convert the files to 352x240 VCD format. I find this results in better quality for me. Capturing at 720x480 usually eats up about 65% of my processor. Also a lot of people here are likely to say Media Studio & PowerVCR suck, and I'm not claiming I'm cranking out DVD quality, but for me the quality is acceptable, and that's really all that should matter.

    One thing I would like to point out is that overclocking your front side bus *may* be causing the problem. Once you raise the speed you stress all of your PCI cards by running them at speeds they weren't designed for. I'm not preaching... I love a good time as much as the next guy, but it's true that some applications run slower on an overclocked machine. Try clocking your geforce and run 3DMark sometime =) In any case it's easy enough to drop your FSB down to 133 and try it again.
    Quote Quote  
  3. Thanks for the info. Regarding the FSB speed, I still had the problem running at 133... I oc'd it to 138 to try and squeeze a little more processing horsepower in the hope it would alleviate my problems... it hasn't. I've tried using Ulead Video Studio 5.0 too... the CPU overhead is MUCH less when capturing to MPEG1 and I get hardly any dropped frames, but I STILL get the 'jittering' / 'jumping' problem. The degree of jittering / jumping appears to be proportional to the quality of the source... if it's a good-ish quality tape, the problem isn't so bad, but if it's a poor quality tape with lots of dot-grain and tracking noise, the jitter / jumping is really bad. I've even tried capturing full frames uncompressed, but still get the jittering problem. It's kinda hard to explain the effect, but it's as though the video gets 'stuck' and jumps back and forth (very quickly) between the point it's stuck at and a few frames back. Then, after a short time (maybe only a second), it continues to play. This happens a apparently random points, but I know it's a capture problem rather than a playback problem. Could it have anything to do with the way my VCR is connected to the WinTV card? I'm using composite video. I'm also using the latest WinTV WDM drivers from Hauppauge.
    Quote Quote  
  4. I would try these.

    http://btwincap.sourceforge.net/

    They made a huge difference for me in terms of resolutions availabe for capture, and they elimated the jagged edges I was seeing using the Hauppage drivers.

    I also use the composite input so that isn't the problem. I do have problems when using my primary drive. I suspect it's an interrupt problem because as it writes to my hardrive during the capture process I get a stutter in the video I'm capturing, and it is very evident during playback. It works fine on my secondary drive, but that is connected to the onboard ATA100/RAID controller.

    Hopefully the drivers I linked to will help.

    Good luck!
    Quote Quote  
  5. I have a similar spec to those mentioned already :
    Athlon 1700XP, Asus A7A266 Motherboard, 512K DDR memory, 40Gb ATA-133 (7200rpm) with 2Mb Buffer, WinTV GO PCI, Windows XP Home Edition. I too get the jumpy motion, but haven't yet tried the drivers mentioned by Sludgehead - maybe that will help.

    My big problem is the dropped frames. In Virtual Dub I'm dropping about 40%, and that's uncompressed AVI. I've tried both the WDM and VFW drivers available on the Hauppauge site, but it doesn't help. I've checked that DMA is enabled on the hard drive.

    cheers
    Quote Quote  
  6. Ritchie

    Have you set your framerate correctly. 25fps for pal, 29.97fps for ntsc. Virtualdub defaults to 15fps which could account for the 40% framedrop

    Craig
    Quote Quote  
  7. It's actually worse when I try 25fps. I've tried all sorts of different configurations/codecs within VirtualDub, but I always get the dropped frames. Are there any benchmark programs that I can run to test the speed of any buses used by video capture so I can determine where it's getting caught behind ?

    cheers

    Ritchie
    Quote Quote  



Similar Threads

Visit our sponsor! Try DVDFab and backup Blu-rays!