Opened 4 years ago

Closed 4 years ago

Last modified 4 years ago

#12759 closed Bug Report - General (Fixed)

VBox channel scan ignores HD channels with transmission type S2

Reported by: karl@… Owned by:
Priority: minor Milestone: 0.28.1
Component: MythTV - Channel Scanner Version: Master Head
Severity: medium Keywords: vbox
Cc: Ticket locked: no

Description

VBox channel scanner retrieves list of channels from VBox and sanity checks transmission type to be T/S/C/A but some HD channels in UK report transmission type as S2 not S so the channel is ignored.

Reporting as "S2" = BBC1/2/4, ITV1 HD - these don't work

Reporting as "S" = Channel 4 HD and Channel 5 HD - these work

Looks like problem may be at line 45 of vboxchannelfetcher.cpp in VBoxChannelFetcher()

Change History (13)

comment:1 Changed 4 years ago by karl@…

Transmission type is set in getChannels() at line 333 of vboxutils.cpp - maybe store as S instead of S2.

comment:2 Changed 4 years ago by paulh

Which model of VBox do you have?

What is the firmware version?

I only have a XTi-3342 which is the 2 x DVB T/T2 model so never tested S/S2 at all. The kind people at Vbox are supposed to be sending me a XTi-3340 so I should be able to test and fix any problems once I get it.

I do know early versions of the firmware didn't differentiate between S/S2 or even T/T2 channels in the channel list, they was all flagged as T or S in the xml channel list.

It looks like the new 2.50 firmware does now add T or T2 and I would assume S or S2 as well in the channel list.

comment:3 in reply to:  1 Changed 4 years ago by paulh

Replying to karl@…:

Transmission type is set in getChannels() at line 333 of vboxutils.cpp - maybe store as S instead of S2.

It's not quite as simple as that because you can tune an S channel on an S2 tuner but not the other way around and I believe the current DVB models only have one S2 tuner and one S tuner?

comment:4 in reply to:  2 Changed 4 years ago by karl@…

I have an XTi-3340 running 2.52. It has 2 x T, 1 x S2 and 1 x S tuner - I haven't tried connecting anything to the 1 x S input yet. Was wondering how the lack of HD channels on the S input would be handled by MythTV... so just trying to get up and running with a single S2 input first.

Not sure if it's how you get the channel list, but vboxXmltv.xml lists BBC1HD as S2-GBR-002008021b1d whereas CH4HD is S-GBR-0020081452d0.

comment:5 Changed 4 years ago by Paul Harrison <pharrison@…>

In bb5daa92807096c4f6fef8b6e55a296c7e9b8bc7/mythtv:

VBOX: bump the minimum firmware version to 2.50

Refs #12759.

comment:6 Changed 4 years ago by Paul Harrison <pharrison@…>

In 0bfcd20950f093fbcd2647021d9c53aa421a5d7f/mythtv:

VBOX: don't ignore channels using T2/S2 if the tuner can handle them

Refs #12759.

comment:7 Changed 4 years ago by Paul Harrison <pharrison@…>

In c9d119a657a07064990ab18176368aa5bf9b0a43/mythtv:

VBOX: bump the minimum firmware version to 2.50

Refs #12759.

(cherry picked from commit bb5daa92807096c4f6fef8b6e55a296c7e9b8bc7)

comment:8 Changed 4 years ago by Paul Harrison <pharrison@…>

In 6386f31c93103dc9e5093cc5a7aae876bce0a7f2/mythtv:

VBOX: don't ignore channels using T2/S2 if the tuner can handle them

Refs #12759.

(cherry picked from commit 0bfcd20950f093fbcd2647021d9c53aa421a5d7f)

comment:9 Changed 4 years ago by paulh

Status: newinfoneeded_new

Please let me know if this is now fixed for you.

One thing I did notice is it is now _essential_ you have a proper start channel in mythtv-setup setup otherwise the BE will either crash, lockup or just sulk and refuse to start live TV.

comment:10 Changed 4 years ago by karl@…

I am running backend on Raspberry Pi 3 on Arch with binary package. Will try to compile from source and test.

comment:11 Changed 4 years ago by karl@…

That code update worked and I can now scan and view all HD channels.

Myth doesn't know that S2 channels are only available on the S2 tuner so will attempt (and fail) to tune an S2 channel on the S tuner if the S2 tuner is busy.

Watching Live TV and switching between T and S tuners will crash the backend within a few channel changes (starting channels are correct in mythtv-setup), but these are different problems - original HD scan problem is fixed - thanks!

comment:12 in reply to:  11 Changed 4 years ago by paulh

Milestone: unknown0.28.1
Resolution: Fixed
Status: infoneeded_newclosed

Replying to karl@…:

That code update worked and I can now scan and view all HD channels.

Ok thanks for testing I will close this ticket as fixed. Please open separate tickets for any further problems.

Myth doesn't know that S2 channels are only available on the S2 tuner so will attempt (and fail) to tune an S2 channel on the S tuner if the S2 tuner is busy.

Ok a couple of things to note :-

  1. Myth assumes it has exclusive access to any capture devices, that applies to all devices not just VBoxes so if another client is streaming from the VBox Myth doesn't know or care it assumes it has exclusive access. The VBox API does allow us to query what is being streamed and could in theory work around the problem by using other tuners or notifying the user it can't switch to a channel because the tuner is in use but I don't think there is anything in Myth to handle this sort of thing yet.
  1. If it's not a problem with other clients using a tuner then it could be a setup problem. The XTi-3340 like you say has 4 tuners total (2 x T, 1 x S2 and 1 x S) For Myth to be able to use those tuners it would require 3 video sources being set up. That is because there are 3 different sets of channels that can be received (The DVB-T tuners can get one set, the DVB-S can get another and finally the DVB-S2 tuner can get another). If you attach the correct video source to the various tuners and do a channel scan for each source then if everything is working as it should Myth should only add the channels that each tuner can tune to that video source. You can verify this is working by going to the channel editor and switch the video source on there to filter the channel list.

Watching Live TV and switching between T and S tuners will crash the backend within a few channel changes (starting channels are correct in mythtv-setup), but these are different problems - original HD scan problem is fixed - thanks!

If you can open a ticket preferably with a backtrace of the crash someone will take a look. I suspect this is a problem with IP streaming playback in general and isn't VBox related.

comment:13 Changed 4 years ago by karl@…

You're right - the tuning problem was due to using a single video source for S + S2 tuners. I subsequently realised this and adding a third video source solved the problem. Thanks for clarifying in your explanation.

I will look into the S/T tuner switch-over crash if it causes problems. I don't use Live TV that much and don't channel surf so it's not a big issue right now.

Thanks again.

Note: See TracTickets for help on using tickets.