[mythtv-users] IPTV 'Manual Schedule' recordings: mythpreviewgen fails and repeats

[John Pilkington]

I'm running the 2019-render head in Fedora 30 with nVidia nvdec 
hardware, and have made several recordings from the French mezzo 
channel, using the Manual Scheduler: 854x480 at 25fps, H.254.  The 
frontend log has lots of lines like:

E PreviewQueue: Attempted to generate preview for 
'xxxx_yyyymmddhhmmss00.ts_0x0_-1s'  1402 times; >= max(50)

Running mythpreviewgen from a script or terminal causes a segfault. 
Adding --size and --seconds made no difference.  Playback says it's 
using nvdec but previewgen says the nvdec check failed.  Same with no 
frontend running.

FireTVstick 4k using ffmpeg doesn't show a preview either, but DLNA 
video and video preview are ok.

Recordings from France 24 English give previews ok, but scheduling 10 
minutes gives a several GB file, hours long...

I don't know whether the problems are in new or old code, so posting 
here initially.

John P