[mythtv] SVN 8625 Firewire capture glitching while test-mpeg2 doesn't

Steve Adeff adeffs at gmail.com
Thu Jan 19 20:42:28 UTC 2006

With Jim Westfall's help I've yet get a 0bit firewire recording, its worked 
everytime. What I notice though is a lot of glitches in the capture. Sample 
log output:
2006-01-19 14:46:12.625 audio waiting for space on soundcard: have 2752 need 
[mpeg2video @ 0x2aaaabffa4c0]MPEG motion vector out of boundary
[mpeg2video @ 0x2aaaabffa4c0]MPEG motion vector out of boundary
[mpeg2video @ 0x2aaaabffa4c0]Warning MVs not available
[mpeg2video @ 0x2aaaabffa4c0]concealing 4265 DC, 4265 AC, 4265 MV errors
2006-01-19 14:46:12.640 audio waiting for space on soundcard: have 5760 need 

depending on the glitch, I may receive between 4-40+ lines like this every 
2minutes or so.

As an experiement, I ran a test-mpeg2 capture on the same channel (though the 
channel doesn't matter), grabbed 1.8GB and played through the internal player 
using MythVideo. This method results in a glitch free capture for the 17mins 
of video.

For MythTV I have the Firewire port set to record via "broadcast", previously 
I had it set to "p2p" as it is what worked when testing with test-mpeg2.

Here's my plugreport for the capture from test-mpeg2:
Node 2 GUID 0x000e5cfffed720aa
oMPR n_plugs=1, data_rate=2, bcast_channel=63
oPCR[0] online=1, bcast_connection=0, n_p2p_connections=1
        channel=63, data_rate=2, overhead_id=0, payload=376
iMPR n_plugs=0, data_rate=2

So then I tried switching mythtv-setup back to a p2p connection to see if that 
fixes the glitches, but it still gets the glitches and doesn't alway get a 

Now I've got mythtv-setup back to broadcast and its working like it was 
before, and for kicks did another test-mpeg2 capture this time on another 
channel, another 1.2GB and again using the internal player I get no glitches 
playing it back (verified by a search through the frontend log).

so it looks like somethings wrong with how MythTV captures via the firewire, 
and I'll be happy to try and help find the problem if anyone has anything for 
me to try.


More information about the mythtv-dev mailing list