Tvheadend

Hypothesis:
I think tvheadend PVR code (in dvr_rec.c) kills the transcoding thread when the recording is scheduled to end, but the transcoder might be behind, have untranscoded frames still buffered in RAM, and this results in the recording being cut short.

• I am running tvheadend on a system with an underpowered CPU.
• When transcoding OTA 1080p ATSC to 720p, one-hour recordings end after 50-55 minutes, although the tvheadend log messages show the recording starting and ending at the scheduled time.
• I see that RSS (as seen in top(1)) for the tvheadend process grows continuously during the program and drops down at the time the program is scheduled to end.
• When transcoding to 480p, one-hour recordings complete successfully and RSS does not grow continuously during the program.

I haven't worked through all of the logic in dvr_rec.c but it appears that when the SMT_STOP event is received it kills the transcode job immediately, doesn't alow it to drain.

This is on Ubuntu 16.04.