[mythtv-users] While watching a show in Time Stretch, audio lags behind

[Mike's JdJ]

While watching a show with a Time Stretch of 2.0, audio starts 
lagging behind the video until unwatchable.

I've noticed this on some recording before, but it is showing up 
on each of the FXXHD Simpsons marathon recordings.

Watching with a Time Stretch of 2.0, the A/V Sync progressively 
increases to about 1500 over a half-minute to a minute.  It then 
jumps to zero and starts increasing again.

Setting Time Stretch to 1.25, the A/V Sync slowly decreases 
until it drops to about 10.  Increasing Time Stretch to 1.5 
starts the A/V Synch slowly increasing again.

Another example is Cinderella on ABCFHD, also 1280x720.

The problem happens when there are no other playbacks or 
recordings.  The PC is dedicated to MythTV only.

The Front End that I am using is on the Back End PC.

However, 2001, A Space Odyssey on TCMHD at 1920x1080 has an A/V 
Sync that hovers around 0.2.

These recordings are made with an HDHR Prime on Comcast.

I also have Hauggauge HVR-2250s for Over-The-Air recordings. 
The OTA recordings such as Penn and Teller: Fool Us and the PBS 
shows at 1920x1080 do not have the A/V Sync problem.


Is this a Comcast "feature"?


I love the Time Stretch.  I watch most recordings at 2.0 or 
1.75.  (I used to hover over the 600 Line-Per-Minute impact 
printer.)  I even have my spouse watching at 1.25 and she enjoys 
the shows.  I was so disappointed that Windows Media Center only 
has a slight stretch.

Mike

Configuration

MythTV fixes /0.25(v0.25.2-15-g46cab93)
Ubuntu 12.04  32 bit
Intel 3.4 GHzx8
500 GB system drive
four 2 TB drives for recordings
HDHR Prime to Comcast
two Hauppauge HVR-2250
Gigabit LAN
Comcast: no "premium" channels, Digital Starter