Opened 15 years ago
Closed 15 years ago
Last modified 15 years ago
#5744 closed patch (wontfix)
Initial tuning to an analogue station fault
Reported by: | anonymous | Owned by: | Janne Grunau |
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Priority: | major | Milestone: | 0.21.1 |
Component: | mythtv | Version: | 0.21-fixes |
Severity: | medium | Keywords: | analog analogue |
Cc: | Shane Shrybman | Ticket locked: | no |
Description
When initiating a tv session, initial tuning to an analogue channel fails. All that is produced is noise rather than a picture.
The fault has been located in: void TVRec::TuningNewRecorder?(MPEGStreamData *streamData) Line 4002 CloseChannel?()
CloseChannel? here is called with with the only file descriptor open on the video device. On certain tv cards at least, closing that single connection will initiate and a sleep state of the analogue frontend with loss of all previous tuning detail. In order to fix this, the CloseChannel? call is moved to a later point where it is known that the video device has been opened for reading elsewhere.
Testing results in success and inspection of file descriptors in use by the backend before and after shows no leakage.
Attachments (1)
Change History (7)
Changed 15 years ago by
Attachment: | TVRec_TuningNewRecorder_mythtv-0.21-fixes-18432.diff added |
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comment:1 Changed 15 years ago by
Cc: | Shane Shrybman added |
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Status: | new → assigned |
comment:2 Changed 15 years ago by
Owner: | changed from Isaac Richards to Janne Grunau |
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Status: | assigned → accepted |
comment:3 Changed 15 years ago by
Status: | accepted → infoneeded |
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on trunk after [19250] it seems to have the different effect. I got a green screen on the first tuning attempt.
comment:4 Changed 15 years ago by
Resolution: | → wontfix |
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Status: | infoneeded → closed |
Info needed but not provided.
This looks like a workaround for broken V4L drivers, should be fixed upstream first, then we can add a workaround for the specific broken driver with version check. That way the hack can easily be removed when all major distros have been shipping non-broken drivers sufficiently long.
comment:5 Changed 15 years ago by
I also have the problem described in this issue. Is there any other workaround or do I need to patch mythtv?
comment:6 Changed 15 years ago by
I applied the patch to 0.22 and everything works fine with (HVR-4000)
I have applied this patch and it works fine with my bttv (V4L2) and pvr250.
I think it also solves a problem I had with the bttv card seeing a second or two of static when first tuning livetv. It also may solve a problem where I only got a black screen on ~ 1/20 livetv startup attempts, I have not been able to reproduce that problem in ~40 attempts with the patch applied.
BTW: The #ifdef USING_V4L appears redundant, GetV4LChannel() has the USING_V4L check.