2004-03-02, 02:29
i've been salivating over the prospects of watching some hdtv streams on xbmc. i haven't been able to find out much about them on the forums (except that everyone seems to be having problems playing them) so i did a little experimenting this afternoon and i don't think the xbox has enough cpu to play them. i'm posting to see if someone will confirm my fears that this is true.
i found a win32 binary of mplayer to test with. i played a few recorded hd streams i have to confirm that mplayer would decode them properly without any tuning. these are 1920x1080 interlaced with ac3 audio streams, using *.ts and *.trp file extensions. all the streams played fine on my 2.6 ghz p4, utilizing between 30-40% cpu (ouch, not expected).
i tried streaming them to the xbox using ccxstream, but the results were poor. i was getting about 7-8 fps while the dropped frames ballooned. thinking perhaps the network was adding some latency, i copied the files local to the xbox. same results, though.
so, is the xbox incapable of playing these hd streams due to hardware limitations? i find this difficult to accept because some games (only a few i think) actually support 1080i as a game resolution. how can the xbox both render, and then raster those frames at 30 fps? this is surely more work than simply decoding the video stream at 30 fps.
are there any optimizations possible to mplayer that might leverage the gpu to offload some of the work (assuming there are none now and the cpu is doing everything alone)? i'm not sure if xbmc mplayer has been optimized for use with the nvidia gpu, but i'm reasonably certain that all nvidia gpus since gf2 have hardware support for all atsc formats.
any thoughts?
i found a win32 binary of mplayer to test with. i played a few recorded hd streams i have to confirm that mplayer would decode them properly without any tuning. these are 1920x1080 interlaced with ac3 audio streams, using *.ts and *.trp file extensions. all the streams played fine on my 2.6 ghz p4, utilizing between 30-40% cpu (ouch, not expected).
i tried streaming them to the xbox using ccxstream, but the results were poor. i was getting about 7-8 fps while the dropped frames ballooned. thinking perhaps the network was adding some latency, i copied the files local to the xbox. same results, though.
so, is the xbox incapable of playing these hd streams due to hardware limitations? i find this difficult to accept because some games (only a few i think) actually support 1080i as a game resolution. how can the xbox both render, and then raster those frames at 30 fps? this is surely more work than simply decoding the video stream at 30 fps.
are there any optimizations possible to mplayer that might leverage the gpu to offload some of the work (assuming there are none now and the cpu is doing everything alone)? i'm not sure if xbmc mplayer has been optimized for use with the nvidia gpu, but i'm reasonably certain that all nvidia gpus since gf2 have hardware support for all atsc formats.
any thoughts?