I'm totally confused. I have both the Videonics Python (Parallel with direct MPEG compression) and I just bought the Belkin Videobus USB (AVI capture). I'm using a IBM Thinkpad 600E with a PII 400, 128MB RAM and a 10Gig HDD.

Here's what I don't understand. Why is the frame dropping so bad when I use the belkin device? I've captured 4MBit/s with my Python without any problems but when I try to capture with the Belkin USB to an AVI (with compression codecs), I get almost 50% (or more) frame dropping. I thought that USB was much better... am I wrong?

Thanks in advance.

-- Donovan (donovan_chin@yahoo.com), August 11, 2000

Answers

USB has higher transfer rate than parallel, but your parallel port device must be only capturing MPEG, right? Your USB device is capturing in AVI. That makes a lot of difference. It could also be your hard disk too slow. When taking in MPEG there is no problem, but when taking in AVI, the problem appears.

But I have never use the Belkin Videobus USB before. Can't help much.

Regards,

-- Rusman E. Priyana (priyana@eudoramail.com), August 12, 2000.

which compression codecs are u using? some codecs require more cpu power than others. and the rez and framerate being set to high can cause frame dropping.

-- ndumu (ndumu@hotmail.com), August 12, 2000.

I'm trying to capture video with a resolution of 352x240 with 30fps. Are there any codecs that you guys recommend for my current config?. I tried MJPEG and some others. All seem to have a lot of frame dropping.

-- Donovan (donovan_chin@yahoo.com), August 12, 2000.

try mpeg4.(microsoft or divx) also indeo 5 - with "quick compress" enabled. if its not,indeo 5 will probably drop alot of frames.

-- ndumu (ndumu@hotmail.com), August 12, 2000.

Problem with all you are suggestions. The raw video still needs to be transfered over the usb device. raw avi, even mjpeg avi is costly interms of space. You sould contact the manufacturer to see what they can do.

As far as codecs are concerned, mpeg4 ( or divx it's the same ) are the bets quality/bits. I prefer svcd mpeg2 actually.

Happy encoding.

-Eric

-- eric (eric@snowmoon.com), August 12, 2000.

So you guys are actually saying that it's dropping frames passing through the device more than writing to the drive?

BTW is there an MPEG-2 real time compression codec available for download?

-- Donovan (donovan_chin@yahoo.com), August 13, 2000.

Mpeg realtime compression vs. AVI (codecs compression).

Your mpeg capture device probably has on board transcoder assist during the compression, which is why you do not experience any frame drop issue. Your USB is capturing and compress in real time without any transcoder assist; Therefore, it is using the CPU as the main compressor. Capturing AVI at 352x240 @ 30fps process great amount of data especially at 4Mbps. On top of that you are compressing it as you move the data with a PII 400Mhz at that! This is why it is dropping frame left and right. Download the Huffyuy codecs (find link at www.vcdhelper.com) and use it instead. This codecs requires very little CPU power, since it captures what you see (120Mb per min). This codecs produces the best results in either MPG1 or MPG2 with either panasonic or TMPEGEnc1.2b.

I am capturing DivX in realtime using a K7-700Mhz with compression fully turned on at 850Kbps(Internal), and this process is already using anywhere between 10% to 45% of the CPU. Now if i turn on realtime filter options, then the CPU % jump up by 2x! Which made the 700Mhz seems underpower! Frames start to drop like flies when the CPU operates at 100% for about 30 seconds. Since you are going to compress it again after capture anyway, then don't use any compression or use it at miminum rate. This will help you eliminate the frame dropping problem.

-- lnguyen (wingstarzz@hotmail.com), August 15, 2000.

Hi

I'm having problems with capturing AVI & converting it to MPEG1 or MPEG2.

PROBLEM 1: Frame-Dropping I have tried BOTH Virtualdub & WINTV video capture software but I seem to have problem of FRAME DROPPING.

I'm in the UK so my WINTV is set ot PAL format. I try to capture at 25fps but it usually results in lots of frame dropping so I do 20fps instead. I also get the same problem if I try to capture AVI at LARGER THAN 320x240.

-MY current IMAGE FORMAT is 24bit RGB. -I use MS MPEG4 codec but even at 25fps I get frame dropping.

Are there any way around this, i.e. to eliminate frame-dropping if I increase the video dimension and increase fps?

PROBLEM 2: AVI2MEG2 & Synchronisation I currently convert AVI to MPEG with AVI2MEG2 v1.24 beta 12.

When I convert AVI (produced by WINTV capture) to MPEG, the video is NOT in-sync with the audio though the audio is OK, i.e. ONLY the video skips a bit. The original AVI however, is perfectly in-sync.

What adjustments to the settings of AVI2MPEG2 do need to make, if any?

Also, what's the difference between AVI2MPEG2 & AVI2MPEG2vfw ? I have a HAUPAUGE WINTV card so which of these 2 is MORE suitable for me?

-- Mike (mikester_the_mp3_man@yahoo.co.uk), March 12, 2001.

Thanks for all that info ppl. My guestion is somewhat related: using "standard" compression, what size would a 2hr movie be in the following formats; .avi .mov .mpg ? This relates to Hollywood videos on the net that claim to be "full" but are varying sizes in any given format. Thanks, G

-- Henry G (go_direct@yahoo.com), August 08, 2001.