[mythtv-users] Problem Playing ATSC Recordings from CBS

Patrick Kirchner patrickkirchner at yahoo.com
Tue Dec 29 17:22:06 UTC 2009


Recordings from my local CBS station are problematic. I've investigated the files and they seem to be bit strange.  SiliconDust tech support states that they are just "odd" in a normal way.  I reported the issue to SiliconDust and this is what they had to say:

"The clip plays fine in everything I can try it in. The only slightly out of the ordinary thing I can see is that the station is using long GOPs to try to compensate for the low bitrate used, which can mean up to a 1 second delay before any video can start to be decoded. Most stations use 1/2 second GOPs, but up to 2-3 seconds isn't unheard of."

Here's the first 100MB of one of the recordings: 


When I play it with MythTV , it starts very jerky/choppy/no-audio and the only way I can get stop the jerky/choppy/no-audio is by changing the time stretch to something other than 0, then back to 0 again. 

When I examine the file using mplayer with the -identify flag, I see odd stuff for the first 10564 lines and only starts playing after 10721 lines of stuff like this: 


Here's the full text of "mplayer -vo null -ao null -identify: 

I can play the recordings successfully with all other media players, just not in MythTV unless I change the time-stretch back and forth after starting the program.

I'm running Trunk and have had the issue months before the office release of .22.  I've done clean installs of Linux, even moving from Ubuntu to Debian and the problem still exists.  My box is a quad-core Intel with a GeForce 8800 GT.  I've tried a number of playback profiles all to no avail.

If anyone could offer me some insight into this I'd appreciate it greatly.



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