On 9/13/07, <b class="gmail_sendername">Ben</b> <<a href="mailto:bluey@iguanaworks.net">bluey@iguanaworks.net</a>> wrote:<div><span class="gmail_quote"></span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I have two channels that I can record perfectly with mplayer but not<br>with mythtv. Using the command<br><br>mplayer dvb://CHANNEL -dumpstream<br><br>I can then play the file back with mplayer (or whatever) and it is<br>
great. If instead, I have mythtv record the program, then when I play it<br>back it is missing a lot of frames and jumps around and sometimes cuts<br>on entirely. This happens if I play it back in mythtv-frontend or with<br>
mplayer.<br><br>Since I'm doing the playback with the same program (mplayer) clearly,<br>the dump of the tv signal is different when recorded from mythtv than<br>mplayer. Why? And this is only true on some channels... for example, FOX
<br>has this problem, but ABC and NBC do not. These are HDTV signals over<br>the air.<br><br>I have an air2pc card with 2.6.22 kernel (debian sid) and myth-0.20.2.<br>All the channels receive >80% signal using dtvsignal. My first thought
<br>was that mplayer was using a different frequency than mythtv was for the<br>channels. Looking at the mysql database, I see under<br>mythconverg/dtv_multiplex/frequency that for the channel in question I'm<br>using the frequency 503000000 and mplayer (in .mplayer/channels.conf) is
<br>using 503028615. So I changed the line in the sql database and restarted<br>mythtv, but that didn't make a difference. I undid that change and added<br>28615 to the mythconverg/channels/finetune but that too had no effect.
<br>I'm stumped as to why saving the stream is different. Any ideas? Both<br>mplayer and myth are running as unprivileged users without suid or<br>anything.<br><br>It goes without saying, but live TV of these channels with mythtv also
<br>doesn't work well, but "mplayer dvb://CHANNEL" is fine. And finally, is<br>there a way to have mythtv-backend use mplayer to save recording and<br>just circumvent whatever problem this is?<br><br></blockquote>
</div>Do you commflag your recordings? If so, there is basically double the disk I/O happening. Also, there is more going on when myth is recording (DB writes, etc) which also increase the I/O over what mplayer is doing with dumpstream. Does your database share the same disk as your recordings?
<br><br>Kevin<br>