[mythtv] Re: [mythtv-commits] Ticket #926: Radio channels for DVB-T

Buechler, Mark R Mark_R_Buechler at bausch.com
Thu Jan 5 00:49:12 UTC 2006

I followed the instructions in dummydtvrecorder.cpp but unfortunately they
don't work. However I managed to get the following working:

# convert /tmp/1280x720.png ppm:- | ppmtoy4m -n15 -F50:1 -A1:1 -I p -r |
mpeg2enc -V 92 -c -n p -f0 -b1152 -a1 --no-constraints -o /tmp/tmp.es

# mplex -f0 -b800 -o /tmp/tmp.ps /tmp/tmp.es

# vlc /tmp/tmp.es --sout

Which resulted in the attached ts. I tried this with at 854x480 but for some
reason I couldn't get that to work. Anyone know why?

- Mark.

-----Original Message-----
From: David Matthews [mailto:dm at prolingua.co.uk] 
Sent: Wednesday, January 04, 2006 12:24 PM
To: mythtv-dev at mythtv.org
Subject: [mythtv] Re: [mythtv-commits] Ticket #926: Radio channels for DVB-T

> In the states, for digital TV we have MusicMatch audio stations, I've
> at least for me they get broadcast in the clear, but the video channel for

> them is not linked like normal channels by the program ID, and when you
> the video ID the video is more like a slide show where an image is sent
> then nothing for some seconds then the next video image. Would something
> this allow me to tune the audio PID and not worry about the video so I
> at least listen to the station?

Possibly.  It simply looks at the filters that are added and uses the 
dummy video if there isn't a video PID in the PMT.  What it will do with 
the MusicMatch stations will depend on what's in the PMT they're 

> This works GREAT for me! Just one (seemingly stupid question), what's
> necessary in order to change the resolution of the blank video frames? I'd
> either prefer a 16/9 aspect or an NTSC (640x480).

I simply copied what was currently used in the dummydtvrecorder except 
that there is extra code in tv_rec.cpp to select different resolutions 
and frame rate for ATSC.  I haven't done that so far because I wasn't 
sure whether the code was useful outside the UK.  If it is then I'll do 

There are instructions in dummydtvrecorder to create your own stream. 
You can then replace themes/default/dummy768x576p50.00.ts with whatever 
you want.  The only constraint is to retain the 50 fps.

Actually, it might be better to change the code to 25 fps for PAL but 
that would have meant creating a new MPEG TS stream and I wanted to 
minimise the changes until I'd had some feedback.


mythtv-dev mailing list
mythtv-dev at mythtv.org


Please Note: The information contained in this message may be privileged and
confidential, protected from disclosure, and/or intended only for the use of
the individual or entity named above. If the reader of this message is not
the intended recipient, or an employee or agent responsible for delivering
this message to the intended recipient, you are hereby notified that any
disclosure, distribution, copying or other dissemination of this
communication is strictly prohibited. If you received this communication in
error, please immediately reply to the sender, delete the message and
destroy all copies of it.

Thank You
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dummy1280x720p50.00.ts
Type: application/octet-stream
Size: 20304 bytes
Desc: not available
Url : http://mythtv.org/pipermail/mythtv-dev/attachments/20060104/bb9e7973/dummy1280x720p50.00-0001.obj

More information about the mythtv-dev mailing list