Opened 7 years ago

Closed 7 years ago

#10839 closed Bug Report - General (Invalid)

V4L Tuner auto-standby causes recording to fail

Reported by: dave@… Owned by: danielk
Priority: minor Milestone: unknown
Component: MythTV - Recording Version: 0.25
Severity: medium Keywords:
Cc: Ticket locked: no

Description

Many USB capture devices power down the tuner when the last user closes the video device in order to save power. Unfortunately, MythTV seems to open the device for tuning, closes it, then re-opens it for recording. This sequence causes the Hauppauge HVR 850 (and likely others) to loose its tune, and we record a white screen.

If I keep a user on the device by running 'sleep 365d < /dev/v4l/HVR850/video' in another window, I am able to capture video. (No sound, but that is a separate issue I've not looked into yet.)

It is arguable that V4L should restore the previous tuner settings when waking it up, but handling this in MythTV should also marginally improve channel switching speeds.

Change History (1)

comment:1 Changed 7 years ago by danielk

Resolution: Invalid
Status: newclosed

Upstream bug. The V4L API specifically requires devices not to lose tuning information when a device is closed and re-opened.

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