On Sun, Jan 18, 2009 at 7:23 PM, Oliver Seitz <info@xxxxxxx> wrote: > Am 18.01.2009, 19:09 Uhr, schrieb Siemen Baader <siemenbaader@xxxxxxxxx>: > >> Hi List, >> >> I am about to set up a video installation with one pc connected to >> 18(!) screens playing mostly pre-recorded MPEG clips as well as a few >> IP based streams and custom visualizations. The MPEG is encoded at >> 1mbps (I think that is fairly good quality, right?) > > For 1680x1050 resolution at 25fps in MPEG2, you should calculate 6MBit per > stream as I recently tested. Quality's terrible with lower bitrates then. > Depends on the resolution and framerate of your videos. Yes - my videos are significantly smaller (640*480), so about 1/6th the pixel size -- I did not mention that, my bad. But thanks a lot for the info. It confirms that the bitrate should be ok for that resolution. For the calculation I used 2mbps as a safety margin -- so this part theoretically still holds. > > > >> >> After doing a few calculations on the volume of the data streams >> within the machine (pci & usb bus, hdd reading spead), it seems >> possible to me to connect all 18 screens using mpeg2-decoding external >> video cards via USB 2.0 (using powered hubs). >> >> So my question is: Do you know of any USB-to-VGA (or DVI) adapters >> that can decode MPEG2 (or any other suitable encoding) in hardware >> that will work with Linux / mplayer? Other media players would also be >> fine. > > Haven't seen something like that, I only know of a USB to VGA adapter > which is very cheap but also very dumb. You can hope to play a 640x480 > video on it, but don't think about using two at a time. Makes sense; if it is all software decoding then this is going to be CPU bound. > > I've tried some things in playing multiple videos and my approach for 18 > screens would be 18 players using cheap onboard graphics or 9 players with > better graphics cards. > > But if you have success with 18 streams at once, tell me, I'd like to know > ;-) Sure ;) I still think it should be possible if the entire decoding & rendering is off-loaded to the video cards. If I can't do it with USB devices I'll investigate putting several PCI video cards with multiple heads into one tower alongside with using stand-alone players... Any breaktroughs I'll post back here just in case anyone is interested. > > Greets, > Kiste > _______________________________________________ > MPlayer-users mailing list > MPlayer-users@xxxxxxxxxxxx > https://lists.mplayerhq.hu/mailman/listinfo/mplayer-users > _______________________________________________ MPlayer-users mailing list MPlayer-users@xxxxxxxxxxxx https://lists.mplayerhq.hu/mailman/listinfo/mplayer-users
