Dropped Frames at 480 lines from Universal BT8xx Driver

[andrewb758]

Hello, I own an ATI TV Wonder PCI card for capturing video, and I am dissatisfied with ATI's driver & software inability to capture interlaced video above 240 horizontal lines. So, going on the knowledge that this card used the Conexant BT878 chipset, I looked into the "universal" BT8xx driver that is available at http://btwincap.sourceforge.net/, and after reading the documentation, learned that the driver specifically supported my card, and that it allowed for interlaced captures (480 horizontal lines), I installed it on my machine. It works nicely at 352x240 and 320x240, but once I start trying 704x480 or 720x480, it begins dropping frames in mass numbers. I have even tried the Super Video CD 480x480 to capture, and it does the same thing. I have tried using both the tuner and the video composite as a source, and they both have the same effect. My only S-Video source would be my DVD player, and that would be really inconveinent to get out of my stereo cabinet. I don't think the source is the problem, though. The resulting video is captured, but as you would expect it is jerky and by no means smooth. It is synchronized, however. I have a fairly recent (more or less one year old) hard disk that is brand name (Maxtor) and 40GB in total size, with a 25GB partition for Windows XP (It has an NTFS filesystem, as well). My processor, memory, etc. are all very recent and certainly fast enough to capture video like this, as you can see from the specs under Computer Details. I have been alternating between using Huffyuv 1.3.1 as a compressor and the PICVideo Motion JPEG compressor. Both have provided excellent results for me previously. I have attempted to capture from VFW applications using the WDM Wrapper, as well as capturing directly from a DirectShow application. I have used VirtualDub (VFW) and the AMCap (WDM) utility available at the BTWinCap web site. Does anyone have ANY idea what could be wrong here, or what I could do to help things here? Maybe an alternate driver? Is there a possible configuration pitfall here? Any input is much appreciated. Thank you in advance.

[drdy111956]

Can you capture with Virtual Dub 740 x 480 for eg, with setttings of " preview mode " and hide video during capture. This is how I have found I can capture w/o any dropped frames from my BT 878 chip , and I only have a PIII 650 .

[andrewb758]

Does the Preview/Overlay setting matter if "Hide Video on Capture" is set? I would think since the video window is gone it wouldn't matter. Could be wrong. I will give it a try, however.