MythTV NZ

I recently got a Hauppauge HVR-900 USB tuner for testing, and I’ve been trying to debug both the analogue and digital driver support for this card. See the V4L Em2880 page for more details.

All of this work is being kindly sponsored by OpenMedia as part of their support for Digital TV in New Zealand.

DVB-T digital support is mostly working and reasonably stable as long as you don’t switch over to analogue. Here is a screen capture taken off DVB-T.

The analogue support is a different matter.

1. I have to make sure that I load the modules in the correct order otherwise it never seems to be able to switch to analogue mode correctly and times out.

   modprobe em28xx
   modprobe em2880-dvb
   modprobe em28xx-audio

2. The analogue picture is usually pretty shoddy. I’ve had a look with both MythTV and TvTime and it appears to be some sort of tuning issue. Occasionally the channel will sort its self out and the picture is as good as the Windows Driver. Most of the time I get some really bad interference in the picture.Here is a picture off TV3 – notice all of the interference on this picture
   

   Below is the TVOne picture. Whilst still not a perfect picture, it is of equivalent quality to the Windows driver for this channel. Problem is the lock isn’t reliable and sometimes when I change channels I end up with the same picture interference as TV3 above.

   
   
3. I keep getting quite a lot of kernel errors like these when changing channels.

   Nov 20 02:54:22 mythtv kernel: FIXME: Write failed, backtrace:
   Nov 20 02:54:22 mythtv kernel: ===============================
   Nov 20 02:54:22 mythtv kernel: 06
   Nov 20 02:54:22 mythtv kernel: ================================
   Nov 20 02:54:22 mythtv kernel: zl10353_read_register: readreg error (reg=6, ret==-19)
   Nov 20 02:54:23 mythtv kernel: FIXME: Write failed, backtrace:
   Nov 20 02:54:23 mythtv kernel: ===============================
   Nov 20 02:54:23 mythtv kernel: 06
   Nov 20 02:54:23 mythtv kernel: ================================
   Nov 20 02:54:23 mythtv kernel: zl10353_read_register: readreg error (reg=6, ret==-19)

4. Switching from DVB-T to Analogue and back takes a long time, and occasionally locks up altogether requiring the modules to be reloaded.
5. Can’t get any audio on analogue channels. Tried all of the tricks on the Em2800 FAQ page.
6. Sadly the HVR-900 has no Nicam stereo support. I get stereo over DVB-T but you need the newer HVR-930 model for a Nicam tuner.
7. They don’t ship the unit with a composite or svideo adaptor as standard so I can’t debug that at this stage

I’ve reported all of the issues to the driver developers and at this stage I’ll have to wait and see what feedback it generates.

This entry was posted on Sunday, November 19th, 2006 @ 2:17 pm on the category DVB Drivers, em28xx. You can follow any responses to this entry through the RSS 2.0 Responses are currently closed, but you can trackback from your own site.