On Tue, May 15, 2007 5:05 pm, Paul G. Allen wrote: > (no subject) eh? Interesting. :) >
Stupid mistake -- mea culpa > On Tue, 2007-05-15 at 16:34 -0700, Lan Barnes wrote: >> This is a race to see where I get the answer first ;-) Yeaa! Kplug wins. I'll cross post the answer to get it in the Myth-users archives. >> I have seen several variations on this question and suspect it may be more >> than one possible problem. >> I recently upgraded from MythDora 3.2 to 4.0 with a reinstall. I did not >> have this problem in 3.2. >> While watching a baseball game, mostly all was OK, but while watching a large thing in motion, like a man running, the white uniform would "stretch" along the axis of motion blurring out like a cartoon character >> leaving streaks behind him. The blur looked pixilated and "caught up" when >> the guy stopped. > > Without seeing it, it sounds like what I spent two years looking for in my previous life working with MPEG-2 video compression hardware. I also see this more than I'd like on nearly every cable and satellite station on the planet. > > The reason this happens in cable and sat. reception is simple, but often ignored by most folks. It's a result of too much compression at the sat. uplink (Note: All TV transmissions come via satellite, unless you're using a TV antenna and licking up local channels). In the quest to make more money, the providers have compressed the data to the ragged edge, causing pixelation and macro-blocking (A macro block is a large square the size of several pixels and often appearing as all one color. They usually appear in multiples of 4). The compressors I worked on could get about 270:1 compression with almost no discernible pixelation, which translates to about 2Mb/second of streaming MPEG-2 video data. After this point, the pixelation becomes worse and worse, but boy does it save bandwidth. By compressing the video a bunch, the providers can get more channels on the sat., thereby making more money off of you and me. > > In the early days of digital TV, I found the picture excellent. As time wore on, I began seeing the crap that I tested for in my previous life (and when we saw it, we repaired the unit causing it). These days I rarely see a HDTV picture I like. > > So, it could be the compression ratio either at the uplink, the > downlink, or in your Myth setup. If your setup can't handle decoding the stream, then this will be the result. If something is configured wrong, this could be the result. If you provider has a screwed up system, this could be the result. > > Since you indicate things were OK before the update, I'd lean toward something being amiss with the newer version of MythDora (as opposed to a problem caused by your provider, receiver, or computer). > > PGA Thanks. I even understood that ... quite lucid. In reviewing the Myth docs and wiki, which seem to span the known universe, I managed to locate an instruction for using the nVidia HW Mpeg-2 decoder, XvMC. http://www.mythtv.org/wiki/index.php/XvMC#Configuration One thing that changed was I activated this before to control color of playback, not realizing it might also improve motion. But I hadn't reactivated it on this install. These are the hazards of doing stuff bu rote. Anyway I reinstalled that configuration, so we'll have to wait for another ball game to see if that was the secret sauce. BTW, the config has two XvMC settings, one with a VIA Unichrome chipset and one without. I wouldn't know a Unichrome chip from a bear in the forest, but my (cheap) MB is chockablock with VIA chips. [EMAIL PROTECTED] sysconfig]# grep -i via hwconf driver: via-ircc desc: "VIA Technologies, Inc. VT8235 ISA Bridge" desc: "VIA Technologies, Inc. VT8366/A/7 [Apollo KT266/A/333 AGP]" desc: "VIA Technologies, Inc. VT8366/A/7 [Apollo KT266/A/333]" driver: via-rhine desc: "VIA Technologies, Inc. VT6102 [Rhine-II]" driver: snd-via82xx desc: "VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller" desc: "VIA Technologies, Inc. USB 2.0" desc: "VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller" desc: "VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller" desc: "VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller" desc: "VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE" Any hints on which XvMC to set it to, VIA or non-VIA? -- Lan Barnes SCM Analyst Linux Guy Tcl/Tk Enthusiast Biodiesel Brewer -- [email protected] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list
