[mythtvnz] Getting DVB-T working under Linux

[Stephen Worthington]

On Fri, 16 Jan 2009 18:33:14 +1300, you wrote:

>Hi everyone,
>
>I recently bought an Asus u3100 USB DVB-T tuner stick and I've been having a
>bit of trouble getting it running under Linux. I believe I have a fully
>functioning channels.conf file for Christchurch (I used w_scan to build it),
>and have come up against the following:
>
>* I'm running ubuntu 8.10, everything's up to date
>* The kernel finds it OK, it shows up in dmesg and an adapter is created in
>/dev/dvb
>* It works under xine - sort of. I can get TV3 to work with both video and
>audio, but with the rest of the channels I only get video (I noticed TV3
>uses a different audio codec).
>* I can't get it to work under mplayer (my player of choice), it seems to
>find it OK but I don't get any video or audio for any channels, and the
>window which usually pops up in X to display the video doesn't even appear.
>I get the following in the console:
>
>Playing dvb://TV3.
>dvb_tune Freq: 698000000
>TS file format detected.
>VIDEO MPEG2(pid=450) AUDIO MPA(pid=400) NO SUBS (yet)!  PROGRAM N. 0

That looks wrong.  The TS file is an MPEG2 Transport Stream.  But it
will contain H.264 video, and that looks as though it is saying the
videos stream is MPEG2, which is not possible for DVB-T.  And it
should be showing two audio streams, AAC and AC-3, for TV3. Definitely
not MPA audio.

>* If I do a dumpstream in mplayer or cat /dev/dvb/adapter0/dvr0 to a ts file
>I can't play it in mplayer, I get "codec 0x50 not found" or if I turn off
>the audio "video stream not found"
>* I've tried both mplayer 1.0rc2 in the main ubuntu repo and the latest
>version out of subversion, both without success
>* If I use Kaffeine it only finds TV3, but it plays that with both video and
>sound
>
>Does anyone have any ideas on what I can try next, reading through the
>mailing list here and on the mplayer mailing list I can't find anyone who's
>come up against this before (which makes me think I'm missing something
>really simple or it's a very difficult problem!)
>
>Thanks,
>Simon

TV3 does both AAC and AC-3 audio.  The other channels are AAC only. So
it sounds like you do not have HE LATM AAC audio capability installed,
but do have AC-3.

The H.264 used here is a little different in that it uses PAFF
interlacing, so you need support for that on interlaced channels.  TV1
and TV2 are progressive (720p).  TV3 is interlaced (1080i), as are
TVNZ6 and TVNZ Sport Extra last time I looked (576i).  The other
channels will be either 720p or 576i.