Opened 9 years ago
Closed 3 years ago
#12522 closed Bug Report - General (Trac EOL)
v4l2 recorders incorrectly call VIDIOC_STREAMON when not using streaming mode
| Reported by: | Stuart Auchterlonie | Owned by: | Stuart Auchterlonie |
|---|---|---|---|
| Priority: | minor | Milestone: | 29.2 |
| Component: | MythTV - General | Version: | 0.27.5 |
| Severity: | medium | Keywords: | |
| Cc: | Ticket locked: | no |
Description
As per discussion on irc
http://irc.mythtv.org/ircLog/channel/4/2015-10-05
if V4LChannel::SetInputAndFormat?(int inputNum, QString newFmt) needs to swap to a different input in order to record from the tuner, it ends up blindly calling VIDIOC_STREAMON (the V4L2 streaming API) on the tuner, when it has not been correctly setup for streaming mode.
The V4L2 recording has no support for the streaming API, so this could never have worked
Attachments (1)
Change History (11)
comment:1 Changed 9 years ago by
comment:2 Changed 9 years ago by
Devin mentioned there was this kind of cruft in there. I was planning on working with him to figure it out, but have not had the time yet.
Changed 9 years ago by
| Attachment: | ticket-12522-disable-streaming-mode.diff added |
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Disable streaming mode for all tuners
comment:4 Changed 9 years ago by
| Milestone: | 0.27.6 → 0.27.7 |
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Reschedule all tickets planned for, but not solved in time for, 0.27.6 to 0.27.7.
comment:5 Changed 9 years ago by
| Milestone: | 0.27.7 → 0.29 |
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Bumping this to 0.29, as it requires a rethink of our device handling
comment:7 Changed 7 years ago by
| Milestone: | 29.0 → 29.1 |
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comment:8 Changed 7 years ago by
| Milestone: | 29.1 → 0.28.2 |
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Moving remaining open tickets to 0.28.2 milestone
comment:9 Changed 7 years ago by
| Milestone: | 0.28.2 → 29.2 |
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Moving remaining open tickets to 29.2 milestone
comment:10 Changed 3 years ago by
| Resolution: | → Trac EOL |
|---|---|
| Status: | new → closed |
We have moved all bug tracking to github [1]
If you continue to have this issue, please open a new issue at github, referencing this ticket.
So some further analysis yields that this is a bit deeper.
Previous tickets #9825, #10519 and #12336 have added code to forcefully remove the streaming capability from MythTV's view of the device.
The real problem is that we are blindly calling either VIDIOC_STREAMON or VIDIOC_STREAMOFF when we aren't even using the device in streaming mode.
Some of the drivers will allow a STREAMOFF even when the device isn't setup for streaming, others will throw "Invalid argument" when trying to disable streaming when it's not active.
When the driver allows STREAMOFF, it will normally fail with an "Invalid argument" to the VIDIOC_STREAMON ioctl, because we never setup the require buffers in the v4lrecorder to use that mode.
See the V4L2 API: http://linuxtv.org/downloads/v4l-dvb-apis/vidioc-streamon.html