I am working on a patch which processes video taken from different sources. We have already set it up to read video from a file, but we would also like people to be able to capture any video on the screen, i.e. online videos they can't download.

To accomplish this we've installed a jit.desktop object in the patch. This works fine on our PCs, but not so well on the Macs. I did some testing and found that at our desired size (720x405) the PC, powerful as it is, could run this operation up to almost 200 fps. On my lowly PC laptop (Windows XP, 1.6 GHz), I was still able to get about 20 fps.

However, running the same basic patch (just the example patch for jit.desktop, modified to our dimensions and with a jit.fpsgui), I only achieved 2.5 fps. This was on a Mac running OS X 10.5.6 with 2 2.8 GHz Quad-Core Intel Xeon processor and an ATI Radeon HD 2600 graphics card. All of these were running Max 5.0.5. I also tried running on several Mac laptops (Macbook Pro with core 2 duo, OS X 10.5.6) with similar slow results when compared with the PC.

I was able to get better results on a Mac which is a little older, running OS X 10.4.11 with Dual 2 GHz Power PC G5 processors and an ATI Radeon 9600 XT graphics card. That ran at about 14 fps.

Any idea why there might be such a large gap between systems? Or maybe any other workarounds that could work when distributed?

Thanks.