[mythtv-users] HDTV/CPU survey

Daniel Thor Kristjansson danielk at cat.nyu.edu
Thu Apr 29 00:06:46 EDT 2004


]If I read what you are saying correctly...  You do not get any jitter with
]720p or 1080i, even on severe camera pans?  But you do with OSD?

Yep, OSD is still a big problem.


]Do you think your FX card works better than the 4 MX?

I think so, with OSD at least. But I haven't been using this MX long
enough to be very sure.


]Have you tried turning on "use video as timebase"?  Do you get full-speed
]playback?

Well so far I haven't done any work on improving either of the
experimental playback modes, if either of them has improved it's
an incidental improvement.


]Hmmm, I will re-try your playback patch and make sure that -O3 is used.  I
]believe I have already tried that, but I will double check.  Last time I
]tried it, video playback was Okay, but did not seem improved over having
]XvMC disabled.  It also caused studdering with any OSD.

Make sure this applies to the libavdecode library, it sets it's own
flags based on whether the release or debug flag is set. It doesn't use
the general myth optimization settings.


]The extra audio buffering is not typically needed, but without it I
]*occationally* get an audio glitch.  I am currently using the onboard
]C-Media CMI9739A audio controller with the intel8x0 ALSA driver.  I have
]also used an old SB Live! which gave me equivalent performance.  I have all
]the audio going out the S/PDIF jack to my pre-amp.

I'm using an Ensoniq 1371, but I had problems with my built-in intel8x0
card. I think this is due to the immaturity of the MythTV audio support.
Unfortunately, audio isn't something I have any expertise in.


]I highly recommend that everyone using the HD-2000 card, use your
]hdtvrecorder patch.  Getting rid of the bad packets definitely improves the
]playback.

Thanks, I'm working on improving this by assembling PES packets and
using the redundant TS packets if the CRC doesn't check out.


]I appreciate the work you are doing on this project.  Sorry I was unable to
]help you with your WB audio problems.

That's ok, I'm laying some of the groundwork for fixing that by parsing
the PES and PSIP packets. For now I'm recording my WB shows from the
NTSC feed.


-- Daniel


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