[SGVLUG] Re: graphics mode, Really about MythTV

[Michael Proctor-Smith]

On 1/24/06, Don Saxton <dsaxton at pacbell.net> wrote:
>
>
> Michael Proctor-Smith wrote:
>
> >On 1/24/06, Don Saxton <dsaxton at pacbell.net> wrote:
> >
> >
> >>I got some experience finding a text terminal and I can report some sad
> >>news.  But first the good news! After several tries I got a modeline
> >>that works on my 2405fpw monitor and MSI version of the nvidia 6600.  I
> >>have the impression that there must be a range of modeline parameters
> >>that will work. I don't think my solution is optimal, but in the range
> >>of ok.  I  am guessing that the xvidtune might help to spruce it up.
> >>One of my requirements is to use this great 1920x1200 to view hdtv at
> >>1920x1080 and 1280x720, So I think I need three modelines. I have
> >>mplayer playing the atsc stream from /dev/dvb/apapter0/dvr0 which has
> >>been tuned by azap, so I am someplace on the map. Concommitant problems:
> >>lircd won't start (serial ir device and serial driver loads)
> >>
> >>
> >
> >Stupid question do you have a lircd.conf file in the right
> >location(that is the step I forgot last time).
> >
> >
> bingo
>
> >
> >
> >> don't know if the 6600 is accelerating mpeg2
> >>
> >>
> >
> >If the binary Nvidia drivers are loaded then you are getting some
> >acceleration (my 2.6Ghz dual xeon system would not play hdtv smoothly
> >with the open source nv drivers), There is another level of hardware
> >mpeg acceleration, with video quality loss.
> >
> >
> nvidea loaded, but I don't understand. The mpeg2 stream is really
> delivered directly to the graphics card?

To clearify software decoders that use the XV output method will let
X-windows do some of the work of decoding mpeg, because a some of that
work can be done by almost any hardware(colorspace changes, scaleing,
some other stuff). The software decorder still has to demux the mpeg
stream, at a minimum, send to video to the video decoder and send
audio to the audio decoder.

Beond the stuff that XV does there is some video cards almost full
mpeg decoding (epia-m mini-itx boards), others just do the cpu
intensive parts like hardware motion compensation. This is reffered to
as XvMC.

> >>(could that be addressed in the dvb drivers?),
> >>
> >>
> >Which card do you have? Unless there is a atsc out there that has a
> >hardware mpeg2 decoder the dvb drivers have nothing to do with
> >playback.
> >
> >
> Ok, so the stream from /dev/dvb/adaptor0/dvr0 is piped directly to the
> 6600. amazing. means for software decode, the decoder is a filter
> between the two, true? I guess I was thinking that I had to manually
> stick the hardware accellerater in like I would a software one.
>
> >
> >
> >> and my alsa config is for sure not right (sound stream
> >>frequently crashs mplayer on a 2.8ghz machine).
> >>
> >>
> >
> >Sound is my biggest problem right now with hdtv and mythtv right now.
> >If I have the signal quality to get a program some times the audio
> >will just quits and I have beautiful video with no sound. Xine crashes
> >are probably not a alsa config problem. I have not used xine to
> >playback hdtv but are you using xine from fedora, xine from xinehq, or
> >xine-hd. What cpu are you using AMD or Intel
> >
> >
> intel p4 running at 2.8ghz.  I had a brief success with xine from yum
> and haven't got back to it. xine-hd had problems compiling even with
> gcc32. From mplayer -ao alsa /dev/dvb/adapter0/dvr0 I get complaints
> that none of the vidx work (although I see video) and something like the
> sound buffer is backing up (burp). actually mplayer crashes with an
> intermitent selection of problems. My guess is that syncing the two is a
> problem if one is choking. I need to read more on alsa config.  I pasted
> the messages below.
>
> >>my goal is to solve
> >>enough problems to get mythtv to crank up. Having fun, just my progress
> >>has so far been a bit soggy.
> >>
> >>
> >
> >Willing to help as I am still trying to find time to make my setup reliable.
> >
> >
> Ok thanks. I think my problem with myth is that I am using dvb drivers
> and am reading too many european solutions. I tell myth that the device
> is /dev/dvb and instead of telling it I have a pchdtv, I tell it it is a
> dvb device. one or both of those has got to be wrong.  I have a tough
> time unscrambling the dvb-t and atsc stories.

You can try "mplayer -ao none" to see if it is a video or and audio problem

> from mplayer on one crash:
>            ************************************************
>            **** Your system is too SLOW to play this!  ****
>            ************************************************
>
> Possible reasons, problems, workarounds:
> - Most common: broken/buggy _audio_ driver
>   - Try -ao sdl or use the OSS emulation of ALSA.
>   - Experiment with different values for -autosync, 30 is a good start.
> - Slow video output
>   - Try a different -vo driver (-vo help for a list) or try -framedrop!
> - Slow CPU
>   - Don't try to play a big DVD/DivX on a slow CPU! Try -hardframedrop.
> - Broken file
>   - Try various combinations of -nobps -ni -forceidx -mc 0.
> - Slow media (NFS/SMB mounts, DVD, VCD etc)
>   - Try -cache 8192.
> - Are you using -cache to play a non-interleaved AVI file?
>   - Try -nocache.
> Read DOCS/HTML/en/video.html for tuning/speedup tips.
> If none of this helps you, read DOCS/HTML/en/bugreports.html.
>
> A:90783.7 V:90779.6 A-V:  4.155 ct:  0.663 601/601 38%  3% 103.2% 576 0
> Too many video packets in the buffer: (292 in 8405371 bytes).
> Maybe you are playing a non-interleaved stream/file or the codec failed?
> For AVI files, try to force non-interleaved mode with the -ni option.
> a52: CRC check failed!
> a52: error at resampling
> alsa-space: xrun of at least 0.113 msecs. resetting stream 99.8% 576 0
> A:90784.1 V:90784.5 A-V: -0.369 ct:  1.074 894/894 41%  4% 69.4% 576 0
> alsa-uninit: pcm closed
>
>