I don't have any answers but will try to provide a sanity check on where I have identical problems and possible provide some clarification if it helps.<br><br><div><span class="gmail_quote">On 5/30/06, <b class="gmail_sendername">
Douglas Wagner</b> <<a href="mailto:douglasw0@gmail.com">douglasw0@gmail.com</a>> wrote:</span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>I have a pcHDTV3000 Card, so i'm picking up a potload of OTA stations. In my local area (which is the same for everyone elses of course) i'm getting ahold of both the Analog and Digital Stations (for instance 2 vs
2.1). Now, in MythTV i've got the Analog Stations filtered out (i.e. They're not in my zap2it profile so they're not "valid" stations via Myth). So ALL of the stations i'm displaying are in fact Digital Stations (HD, Non HD, I don't know, but they're all at minimum Digital).
</div></blockquote><div><br>Same setup here except I am using Dvico Fusion Gold card. I also filtered out all sdtv stations (typically with channel numbers with the format of X.2 rather than X.1)<br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>Here's where my issue comes in, when I tune to a station, say 9.3 (pbs) I get digital television displaying what PBS is displaying, sound and video seem to be synced up just fine. When I then switch to 30.1 (ABC? I think - Grey's Anatomy, Alias, Commander in Chief, etc.) I get video with audio out of sync...we're talking 200 - 300 ms out of sync...mid distance past the "is it really out of sync or am I just seeing things?" but certainly not into "OMG that's WAY wrong". It's out of sync enough that it's noticeable and annoying without being unwatchable (other than the annoyance factor).
</div></blockquote><div><br>Exactly identical to problems i see. The easy way to define whether a show is HDTV is whether it is 16:9 or 4:3. I would say all my 16:9 shows are 200-300mS off and most, if not all, 4:3 programs are synced up well.
<br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div>Now, when I go to record shows: When I record something on 9.3 (pbs) which plays synced up, it records just fine and is perfectly in sync. When I play back something recorded on
30.1 the recording is about 2 seconds off the audio (people talk and then you hear the audio)...which is COMPLETELY unwatchable in any way at all.
</div></blockquote><div><br>I do not have this problem. My recorded shows have the same sync has live tv. Well, actually I never watch live tv but basically all my 16:9, HDTV shows have audio 200mS behind video.<br></div>
<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div><br>1) The Live TV out of sync problem is due either to my machine not being able to keep up in playing real time HDTV Streams (it's a
2.8G Pentium 4 HT Processor with 1G of memory, nothing else besides myth frontend/backend/mysql/httpd running) or MythTV isn't able to sync it up right for some reason.
</div></blockquote><div><br>I have a 3.2Ghz pentium 4 HT that is lightly loaded even with HDTV. <br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>2) The fact that the playback is farther off than the live show itself suggests that the ENTIRE problem is mythTV's issue, NOT the stations issue. That belief is exhaserbated by the fact that the videos play just fine on Xine outside of MythTV (if the show was recorded with sound/video off then it would be off played through xine as well), and my TV set with NO myth attached (just direct to TV) does just fine as well (there's no processing inside a TV that would sync up that audio/video stream, so it's GOT to be comming in synced up from the broadcast).
<br><br>The final "hum, that's interesting" note to this whole thing is that the recordings i'm doing on the various stations fit into two completely difering categories: 1) Kids shows recorded off of PBS running during the daytime and 2) "Parent" shows running in prime time recorded off of (generally) ABC(?).
</div></blockquote><div><br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div>Now, I'm going to make the guess, and I think correctly, that the kids shows i'm recording are probably NOT being broadcast in HD with Dolby sound, but i'm pretty darn sure that Alias and Greys Anatomy sure as hell are. Tomorrow night i'm going to sit down and try to narrow the variables down alot more, see what I can find out. I also have a few possible things to try:
</div></blockquote><div><br>
I assume this goes back to what shows are HDTV and what is SDTV.
Again, I would say I have problems on all 16:9 shows and no problems
with 4:3 shows. That does coincidentally line up with kids shows and
parent's shows for the most part. </div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div>1) could I be running into an issue where XvMC is actually hurting the performance or causing this issue?
</div></blockquote><div><br>I don't use XVMC. <br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div>2) Could Transcoding (which is supposed to fix audio sync issues) either be broken and making it worse or not working at all and not syncing up the audio? How can I tell whether a recording has been transcoded and to what? Where's good documentation on the whole transcoding thing and how it works/what it does/how it's setup?
</div></blockquote><div><br>I have never tried transcoding. <br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div>Again, general and somewhat random thoughts to re-start this discussion.
</div></blockquote><div><br>My random thought-<br>-I once read that a weak signal can hurt A/V sync. I do indeed live in the fringe zone so that is possible for me. How strong is your signal? That would not explain your 2-3 second problem but it might the 200-300mS on live tv.
<br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div>Now to your questions directly:<br>----------------------------------------------------------
</div><div><span class="q"><br>ok, let me make sure I understand. You've got an ATSC/QAM tuner card.
<br>you pick up a bunch of HD and digital SD stations. digital SD stations<br>do not pose a problem with audio sync but *all* your HD stations do?<br></span></div><div>-----------------------------------------------------------
<br>This is partly where my issue comes from, I can't tell which stations are HD and which are digital SD. If you assume that PBS is a Digital SD while something like an ABC, CBS and NBC are all HD stations then you get farther with the discussion by saying yes to this. I don't know which stations during prime time programming / HD broadcast all correctly record and which don't...that's a task I need to find out tomorrow.
<br><br>-------------------------------------------------------------</div><div><span class="q"><br>If so, then lets assume whatever the issue is has to do with HD<br>stations use of AC3 sound.<br><br>Are you using digital out of your soundcard to a receiver or are you
<br>running analog output from the soundcard to your receiver?<br></span></div><div>---------------------------------------------------------------<br>There is no digital sound in the setup other than what's comming in over the broadcast wire. Once it hits the pcHDTV3000 card it is going out the PCI slot (I have tried with both the patch wire between pcHDTV3000 out and soundcard in and without it, same effect) to the Sound Card's Bus, to the sound card, and out through the ANALOG out through a Mini->RCA plug (single mini plug in the green analog out hole of the SB Live! Value Digital card I have, to the Red/White RCA audio in on the TV I have. FYI the video is getting to the tv Via DVI->HDMI cable). There is no subsidiary receiver at all in this setup, just the TV itself.
</div></blockquote><div><br>I have used both spdif and analog connections. Alsa and just normal old default device. Same problem no matter how I hook it up.<br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>--Doug</div><div><span class="e" id="q_10b854b6483d541b_5"><br></span></div></blockquote></div><br><br>Doug- You said you were going to post something on the developers list. I am not subscribed there. Did you get any responses or learn anything new there?
<br>