[alexishuxley]

~/dvb_channel.conf shows for ITV1 the following:

[ITV1]
        SERVICE_ID = 8261
        NETWORK_ID = 9018
        TRANSPORT_ID = 20544
        VIDEO_PID = 1701
        AUDIO_PID = 1702 1703
        PID_86 = 1735
        PID_06 = 1731
        PID_05 = 8000
        FREQUENCY = 514000000
        MODULATION = QAM/64
        BANDWIDTH_HZ = 8000000
        INVERSION = AUTO
        CODE_RATE_HP = 2/3
        CODE_RATE_LP = AUTO
        GUARD_INTERVAL = 1/32
        TRANSMISSION_MODE = 8K
        HIERARCHY = NONE
        DELIVERY_SYSTEM = DVBT

I've recorded three files with the following commands:

    dvbv5-zap -c ~/dvb_channel.conf -p -t 60 ITV1 -o ~alexis/itv1-60s-with-option-p.ts
    dvbv5-zap -c ~/dvb_channel.conf -P -t 60 ITV1 -o ~alexis/itv1-60s-with-option-P.ts
    dvbv5-zap -c ~/dvb_channel.conf -P -p -t 60 ITV1 -o ~alexis/itv1-60s-with-option-P-and-p.ts

(I didn't know if doing -P -p made sense, but thought it best to do it anyway.)

I'm confused by what mplayer and vlc play for each file, but perhaps with the multiplexing it make sense to you:
 
    for the first file mplayer plays ITV1 without subs, vlc plays ITV1 without subs
    for the second file mplayer plays something else (can't tell what as no logo, but not ITV1) without subs (but it was recording TV adverts), vlc plays ITV3 with subs
    for the third file mplayer plays CH4+1 without subs, vlc plays ITV3 with subs (i.e. no player plays ITV1)

Links to the three files are itv1-60s-with-option-p.ts, itv1-60s-with-option-P.ts and itv1-60s-with-option-P-and-p.ts, also there's the entire dvb_channel.conf. Many thanks!

Alexis

[emveepee]

OK with -p there is no subtitle stream in the file (pid 1731/0x6c3) but that stream is there with -P.  The conf file seems ok.  This looks like a problem at the kernel or mediatree level.

Ignore trying the -P as I said the are a full mux and contain many programs (channels)  I will use to feed one of my devices to see what happens with it though.

Martin

[emveepee]

My test on your input file was originally the same, the NextPVR stream created from the full mux didn't have the subtitle track.  However editing the conf file and removing some junk streams

        PID_86 = 1735
        PID_05 = 8000

it worked with NextPVR and dvbv5-zap.  Try a test and rewrite the conf file maybe use grep -Ev 'PID_05|PID_86' adapter0-frontend0-DVB-T-channels.conf as the input.

If that works maybe move over to the NextPVR forum, sub the author may need filter some of these unknown PID from the capture.  This is live tv streaming from NextPVR.

[alexishuxley]

Hmm ... I could not reproduce your results. I tried several times (hence longer-than-average time to reply to your message).

(Summary of what I did stripped as forum software thought it was a log and blocked me posting. Link to log below.)

mplayer played all three files but without showing subs, but all different stations. vlc crashed with all three files after a couple of seconds. I didn't try with nextpvr as I figured dvbv5-zap was lower in the stack than nextpvr and so if dvbv5-zap wasn't working then there was no way nextpvr could work. I wonder if Debian 11's dvdv5-zap and vlc are too old.

Links to the output files are itv1-60.ts, itv1-60-with-P.ts and itv1-60-with-p.ts. Also, the (only slightly trimmed to remove 'ls', etc) log, which shows a lot of errors from dvb5-scan, is at log.txt. Also: dvb_channel.conf.

I noticed one very odd thing: there are no BBC stations discovered and there should be several. Is there any chance that all problems (missing subtitles, missing channels) are caused by a bad antenna?

Thanks for your help!

Alexis

[emveepee]

NextPVR uses libdvbv5 so testing with dvbv5-zap is fine.  However NextPVR does use a build of the latest version so cold test with with this

LD_LIBRARY_PATH=/opt/nextpvr/system/DeviceHost/yourplatform dvbv5-zap ....

Why are you running as root?

For Crystal Palace Freeview check https://ukfree.tv/transmitters/tv/Crystal_Palace check the source frequencies on Debian mine seem to match. I am not in the UK and don't have access to dvb here in Canada but I do seem to remember reading on the NextPVR forums that there were a move that required a different antenna a few years ago.  There is more stuff going on with BBC right now but I think that is dvb-s

Martin

[alexishuxley]

Using 'LD_LIBRARY_PATH=/opt/nextpvr/system/DeviceHost/x64 dvbv5-zap ...' made no difference, which is kind of reassuring.

I'm running as root because I installed nextpvr kind of expecting everything would work and consequently had not added myself to the 'video' group to get access to /dev/dvb/*/*. When it became necessary to use those devices myself, then quicker than adding myself and later removing myself from the video group, was to just run as root.

Regarding Crystal Palace/BBC: I'm actually trying to set this up for my mum who is partially deaf (hence absolute need for subtitles), but the setup is complicated by her being in the UK (nearest tranmissing Crystal Palace) and me being in Germany :-) The dvb5-scan and nextpvr commands have all been run on Debian 11 in the UK, the mplayer/vlc/kodi/server-providing-my-urls have all been run in Germany (with kodi talking via ssh tunnel to nextpvr:8866). All "does the real TV show subtitles?" questions have triggered phone calls to my mum like "Mum, on ITV1 *now* are there subtitles? Okay, then I'll record now!" :-) She's running Linux because it's what I know best and I can easily provide her with remote support (vnc via ssh tunnel, etc).

The current setup has the Hauppauge USB DVD device using a table-top aerial close to her desktop computer, whereas the real TV is connected to the wall socket leading to the roof-top aerial. Her desktop computer and her wall socket for the aerial are in different rooms: hence the use of the (inferior?) table-top aerial on the USB device. In ten days I will visit her so if the aerial quality is an issue, hopefully everything will work when I connect the USB DVB device between the roof-top aerial and my laptop. I'll let you know!

Many many thanks for your help! It's greatly helped my understanding!

Alexis

[emveepee]

Your full mux and single channel captures are high quality so I suspect it is something else.  Personally if I was doing remote support I wouldn't bother with a cheap USB device and  a table top aerial.  Hauppauge technically only supports Ubuntu and I don't think they officially support Jammy yet.  You might want to ask a  question on the issues on b-rad's  github https://github.com/b-rad-NDi/Ubuntu-medi...el-builder to see if this is a known issue.  The question is why does the full mux contain the dvb subtitle stream and the program filtered file is missing it.

I don't know if there is much more i can do, good luck.  Perhaps try TVHeadend, I don't think they use libdvbv5 and it might read the full mux.

Martin

[alexishuxley]

Thanks Martin. I'll give tvheadend a go tomorrow, but I'll only update here once I've also tried the aerial swap. Alexis