[mythtv-users] Ivtv recorded MPEG-2 Quality

[Mark Wormgoor]

Jos Hoekstra wrote:
> Mark Wormgoor schreef op 10-9-2008 13:27:
>> Hi,
>>
>> I recently got a Buffalo Linktheater to replace my bulky frontend. When
>> I first connected it, it could not play any of my recordings. I've had
>> to transcode all of them using the lossless MPEG-2 transcode first,
>> before I could play them. It also helps if I simply copy them using
>> mencoder (mencode recording.mpg -oac copy -ovc copy -of mpeg -o
>> recording2.mpg). Both methods fix the mpeg and will allow the
>> Linktheater to play the recording. I've been having the exact same
>> problems when trying to play recordings in Windows Media Player, but had
>> always attributed that to MS :)
>>
>> Now, my recordings are working, as I've setup the automatic transcode.
>> However, this is far from ideal. I have to wait until the recording is
>> finished, commercials are flagged and the transcode has taken place
>> beforeI can watch the recording.
>>
>> The problem occurs on both my Hauppauge PVR-150 and PVR-250. I'm running
>> CentOS 5 with the ATrpms MythTV rpms (currently @ 0.21-fixes svn17961).
>> I'm also using ATrpms' latest ivtv module (ivtv-kmdl 0.10.6-132 on
>> kernel 2.6.18-92.1.10.el5).
>> SNIP
>>
>> Does anyone have a clue what's causing this?
>>
>> Thanks,
>>
>> Mark Wormgoor
> 
> As far as I know you can use a couple of different profiles, like 
> MPEG2-PS, TS and DVD, and that's where your Linktheater probably fails. 
> Which setting you should have for it I don't exactly know, but that's 
> where you need to be for correcting the setting.

I haven't changed the default, which is to record as MPEG-2 PS. It's set 
to the default PAL resolution (720x576). When I check the file with 
mplayer, it tells me the same format before or after the transcode 
(MPEG2-PS, 720x576). Mplayer will actually display errors during the 
transcode like the following:
BUFFER UNDEFLOW at stream 0, raising muxrate to 1980 kb/s, delta_scr: 223418
BUFFER UNDEFLOW at stream 0, raising muxrate to 2178 kb/s, delta_scr: 203107
ERROR: scr 0.349, dts 0.000, pts 0.320
ERROR: scr 0.487, dts 0.000, pts 0.392

The buffer underflow (notice the missing R there :-) ) will only appear 
about 11 times. The error message appears 10,000 times for a 6 minute 
recording, which is a little over 25 for each second.

Kind regards,

Mark