Jerry Rubinow wrote: >On 1/30/06, Dan Seddon <[EMAIL PROTECTED]> wrote: > > >>Hi Jerry >> >>Video comes to about 30 Mbytes per second - which would be about 240 >>Mbits per second, as you're almost a multiple of 3 bigger I'm guessing >>you assumed 24bits per colour channel? Where it is actually 8bits per >>colour channel (PAL is 3*720*576*25 bytes). This ought to be well inside >>the speed of PCI - if you think about it, uncompressed PVRs have existed >>for some years now and the harddrives on these use the PCI bus. So, it's >>unlikely you've exceeded the bandwidth. 60 frame/sec is interlaced NTSC >>(720p is progressive) - I wouldn't think this would increase the >>bandwidth unless you were doing something like bob deinterlace on your >>CPU (I'm guessing here), as each frame should have half the number of >>lines. I don't know about XvMC - I don't know how compressed the data is >>by the time it gets to the card - you'd hope it was a little compressed >>though! >> >>Ta >> >>Dan >> >> > >Hi Dan, > >PVRs have existed for a while, but not HD-resolution PVRs - they're >pretty recent. If X is in a 24-bit depth mode, then I don't see where >my numbers are off - 24 (bit depth) * 1280 * 720 (screen res) * 30 >(fps) = 630+ Mbits/sec. >
Sorry Jerry - My mistake, you're right or course! Confusion on my part about what 720p was - I saw the 720p and assumed this was EDTV...... HD isn't out over here yet, so I should probably check before go getting my numbers wrong ;) Ta Dan _______________________________________________ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
