NextPVR Forums
  • ______
  • Home
  • New Posts
  • Wiki
  • Members
  • Help
  • Search
  • Register
  • Login
  • Home
  • Wiki
  • Members
  • Help
  • Search
NextPVR Forums Public Developers v
« Previous 1 … 14 15 16 17 18 … 93 Next »
Non-broadcasting channels

 
  • 0 Vote(s) - 0 Average
Non-broadcasting channels
imilne
Offline

Posting Freak

Posts: 2,423
Threads: 135
Joined: Feb 2008
#1
2011-04-12, 12:49 PM
Background to this here (http://forums.nextpvr.com/showthread.php...oadcasting)

Short summary: many channels in the UK "timeshare" their bandwidth with other channels, meaning the channels don't broadcast 24/7. When NPVR tunes into a non-broadcasting channel, it acts like it's frozen, and usually shows either a black screen with no OSD, or a frozen picture from the preview channel, again with no OSD.

I've been sitting on a plugin solution to this for a while - TimeSharer - which lets the user change the tuning information for these channels so that NPVR tunes into an alternative channel that *is* broadcasting during the times that they are normally off air.

I wanted one last discussion about it before releasing it though.

Here's sub's comment from another thread (http://forums.nextpvr.com/showthread.php...dcasting):

Quote:Unfortunately the video renderers typically wont update the screen in any way until it is displaying the next frame of video, so when you switch to a channel with no video currently transmitting, the old frame stays on the screen, with no way to make it go black, and no update to the OSD graphics even though the app is telling the renderer to display them.

I guess the main question for sub is: is there really nothing (easy) you can do about it? NPVR seems to manage ok with radio stations (which obviously have no video) but perhaps a different type of graph is built for them?

My plugin works by changing the "local" cache of channel data within NextPVR.exe, so only Live TV is effected; scheduled recordings will still have the correct information in the DB.

To do this, it updates the database with these "fake" values, tells NPVR to reload its settings, then instantly resets the database to the correct values. This does mean the database contains the wrong information for a tiny fraction of a second, which worries me slightly, although technically it wouldn't change the database when a recording was scheduled because the channel must be on-air anyway. I still don't like doing it though. Perhaps there's a way I could override NextPVR.exe's details directly via the API, rather than via the DB?

I've tested it with DVB-T and DVB-S (with merged channels between them too). I have no idea how it would perform with anything else, but maybe that doesn't matter if it's a UK-only problem.

There's some basic documentation on it here (http://www.nextpvr.com/nwiki/pmwiki.php?...TimeSharer) that I wrote yonks ago but never finished. It's actually a very simple problem/concept that I find difficult to explain Big Grin

Iain
sub
Online

Administrator

NextPVR HQ, New Zealand
Posts: 106,791
Threads: 769
Joined: Nov 2003
#2
2011-04-12, 08:33 PM
Can you try watching one of these offline channels, then right click to see the context menu, then zip and attach the npvr.log?
imilne
Offline

Posting Freak

Posts: 2,423
Threads: 135
Joined: Feb 2008
#3
2011-04-13, 07:23 AM
sub Wrote:Can you try watching one of these offline channels, then right click to see the context menu, then zip and attach the npvr.log?

Hopefully this is what you're after.

I used the TV Guide to start Live TV on the "CBBC Channel" which was on-air at the time. I then changed to "BBC Three" which wasn't, but uses the same frequency as CBBC when it is.

Iain
sub
Online

Administrator

NextPVR HQ, New Zealand
Posts: 106,791
Threads: 769
Joined: Nov 2003
#4
2011-04-13, 05:48 PM
Did you right click to view the context menu after changing to when BBC Three? I cant see the item I was looking for in the log.
imilne
Offline

Posting Freak

Posts: 2,423
Threads: 135
Joined: Feb 2008
#5
2011-04-13, 06:08 PM
Yep, I'm pretty sure I did. I even used the context menu to exit NPVR. I'll run through it again in a wee while to be sure though...
sub
Online

Administrator

NextPVR HQ, New Zealand
Posts: 106,791
Threads: 769
Joined: Nov 2003
#6
2011-04-13, 06:33 PM
When you right click, you should see log messages like those below. These are what I want to see for a non-broadcasting channel.

Code:
2011-04-14 06:27:54.034    [INFO][1]    GetCurrentMetadata()
2011-04-14 06:27:54.034    [DEBUG][1]    Current meta data:
<ServiceInformation>
  <Service>
    <ServiceID>1910</ServiceID>
    <PMT_PID>271</PMT_PID>
    <Streams>
      <Stream>
        <PID>517</PID>
        <StreamType>2</StreamType>
      </Stream>
      <Stream>
        <PID>579</PID>
        <StreamType>6</StreamType>
        <teletext_descriptor>
          <page lang="eng" teletext_type="1" teletext_page_number="100"/>
          <page lang="eng" teletext_type="2" teletext_page_number="801"/>
        </teletext_descriptor>
        <stream_identifier_descriptor>
          <component_tag>67</component_tag>
        </stream_identifier_descriptor>
      </Stream>
      <Stream>
        <PID>655</PID>
        <StreamType>4</StreamType>
      </Stream>
      <Stream>
        <PID>1001</PID>
        <StreamType>11</StreamType>
        <stream_identifier_descriptor>
          <component_tag>11</component_tag>
        </stream_identifier_descriptor>
        <data_broadcast_id_descriptor></data_broadcast_id_descriptor>
        <unparsed_descriptor>0x13</unparsed_descriptor>
      </Stream>
    </Streams>
  </Service>
</ServiceInformation>
imilne
Offline

Posting Freak

Posts: 2,423
Threads: 135
Joined: Feb 2008
#7
2011-04-13, 06:59 PM
Nope, it looks like that just doesn't show up when you right-click on a non-broadcasting one. The (empty) entries are there though:

Code:
2011-04-13 08:13:49.569    [INFO][1]    GetCurrentMetadata()
2011-04-13 08:13:50.069    [DEBUG][1]    No service description available
2011-04-13 08:13:50.076    [INFO][1]    GetCurrentMetadata()
2011-04-13 08:13:50.576    [DEBUG][1]    No service description available

I've attached what you *do* get from BBC 3 at the moment (which is on air now, but wasn't during the previous log). It timeshares with CBBC (which is now off) so it might give you what you're after.

You can get PID/SID/etc data for them here (http://www.flysat.com/astra28.php) listed under 10773 H. Perhaps that will help too. This was with DVB-S, but they also timeshare on the same DVB-T multiplex too.

If there's anything else you need, just shout...

Iain
sub
Online

Administrator

NextPVR HQ, New Zealand
Posts: 106,791
Threads: 769
Joined: Nov 2003
#8
2011-04-13, 07:19 PM
When you switch to one of these off air channels, does the live tv buffer file grow, or stay at zero bytes?

Also, could you do a DVB-T scan, and post the npvr.log? I want to see some of the metadata about these non-broadcasting channels. I want to see if I can tell they're present, but not currently broadcasting.
imilne
Offline

Posting Freak

Posts: 2,423
Threads: 135
Joined: Feb 2008
#9
2011-04-13, 08:19 PM
sub Wrote:When you switch to one of these off air channels, does the live tv buffer file grow, or stay at zero bytes?
Stays at zero.

sub Wrote:Also, could you do a DVB-T scan, and post the npvr.log? I want to see some of the metadata about these non-broadcasting channels. I want to see if I can tell they're present, but not currently broadcasting.
I've just scanned a single multiplex to try to keep it less cluttered for you. The two channels currently off air in that set are "CBBC Channel" and "CBeebies".

NPVR has always found all the offair channels during its scans, unlike GBPVR which would only pick them up when they were active.

Thanks for taking the time to look at this sub. It would be great if it turns out there's something you can do about it, but we can always fall back on my plugin if not.

Oh, and if you skim this list you'll see just how many of these ruddy part-time channels we have.

Iain
bgowland
Offline

Posting Freak

West Yorkshire, UK
Posts: 4,591
Threads: 386
Joined: Dec 2004
#10
2011-04-13, 08:59 PM
Just some observation on the channels when they're off-air.

According to TSReader, the PCR is set to being on PID 8191 (0x1fff) the Null Packet PID.

Pretty much all other data is there in the PAT, PMT, SDT, NIT etc and the only difference seems to be they don't carry the AV elementary streams.
« Next Oldest | Next Newest »

Users browsing this thread: 1 Guest(s)

Pages (2): 1 2 Next »


Possibly Related Threads…
Thread Author Replies Views Last Post
  is there a service?method which returns listings for multiple channels? reven 16 7,326 2022-04-11, 04:30 PM
Last Post: mandai
  Channels List by Channel Group Name scJohn 1 2,830 2018-01-05, 10:45 PM
Last Post: mvallevand
  Switching Audio Channels spitefulgod 0 2,057 2016-12-15, 08:42 PM
Last Post: spitefulgod
  Merged channels mvallevand 3 2,740 2014-04-11, 04:55 AM
Last Post: mvallevand
  Scan for channels programmatically or via command prompt? reven 12 5,439 2013-03-08, 05:01 AM
Last Post: reven
  Recording without mapped channels. mvallevand 11 4,225 2009-09-06, 05:09 AM
Last Post: mvallevand
  Switch Channels in Inset JavaWiz 2 1,689 2008-07-27, 06:03 AM
Last Post: JavaWiz
  mapping satellite channels to EPG kainat 26 10,491 2008-02-19, 01:49 PM
Last Post: kainat
  Over-the-air channels with Yahoo/API jdonth 82 29,919 2007-09-20, 08:20 AM
Last Post: whurlston
  Channels out of order... zehd 7 2,822 2007-08-26, 09:42 PM
Last Post: sub

  • View a Printable Version
  • Subscribe to this thread
Forum Jump:

© Designed by D&D, modified by NextPVR - Powered by MyBB

Linear Mode
Threaded Mode