Can capture at 320x240 but not at 352x228 ??

[nmisys]

Hi,

Hope someone can help me here. I've finally managed to get my PC to capture 25fps video/audio without dropping frames using 320x240 (NTSC). I was having frame loss of about 40% until I upgraded my video driver and reinstalled my WinTV card drivers.

However as I'm in the UK (PAL) I need to capture at 352x228 so that the video I'm creating fills the screen.

Unfortunately, although I can capture at 320x240 using either Picvideo MJPEG or Huffyuv v2.1.1 with less than 1% frame loss, whenever I up the resolution to 352x228 the frame loss just goes crazy (without changing any other params).

I've tried capturing video only, but the problem is the same. I've tried using different compressors or no compressors but without success.

The PC is a 1GHz Athlon, 512Mb RAM and plenty of hd space. DMA is ON on the capture drive and I've disabled as much stuff as possible (its running on Win2K).

Any advice on what to try next gratefully received.

Thanks

[spine]

I had the same problem. I solved it by switching to iuvcr for capturing. It uses Directshow for capturing and allows for more captures sizes. Before I could not get anything larger than 352x 240. Now I can go to 640x480 using huffy codec along with the highest quality sound. I can do whatever I want on my computer at the same time and I loose 0 frames. My system: Winxp pro,Hauppauge wintv pci,Athlon 1333 and 512m ram.

[HillJack]

Isn't NTSC 352x240 and PAL 352x288, not 228? Maybe try the proper resolution


<font size=-1>[ This Message was edited by: HillJack on 2001-12-31 19:46:40 ]</font>

[Greg12]

Why would u want fewer lines.

[nmisys]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR size=1 color=black></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2001-12-31 19:45:51, HillJack wrote:
Isn't NTSC 352x240 and PAL 352x288, not 228? Maybe try the proper resolution


<font size=-1>[ This Message was edited by: HillJack on 2001-12-31 19:46:40 ]</font>
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR size=1 color=black></TD></TR></TABLE>

Actually the 228 was a typo....

I've found that by using huffyuv I can now get reasonably good results at 352x288 with about 1-2% frame drops using the same hardware.

Watching the various params when virtualdub is capturing, the CPU is not being taxed (between 20-50% normally), so its either too slow a hard drive or the PCI card just cant keep up.

I'm inclined to believe its the WinTV card as its prob. about 4+ years old now.

[HillJack]

If you think its your PCI card that can't keep up, try disabling the preview in VDub while capturing... It's specifically made to "save PCI bandwidth." That could help you recover those extra few frames.