[mythtv-users] Easier analog channels for pcHDTV 3000 (and 5500) owners

Sun Mar 23 02:03:18 UTC 2008

> In case you didn't know (I didn't until recently), the
>  HD3000 and HD5500 can receive analog signals without
>  messing with that hoaky "connect the tuner to your line-in
>  port" kludge that pcHDTV suggests.
>
>  The chip on these cards has a built-in A2D converter that
>  can DMA to main memory. What this means is, you can get the
>  analog signals over a plain, vanilla V4L interface -
>  /dev/video* and /dev/dsp*.
>
>  Here are the steps that I went through to get it to work.
>  I have a 2.6.20 kernel and myth 0.20.2 (Ubuntu Feisty).
>
>  1. See if your tuner card has the audio port enabled:
>
>  lspci | grep -i 'audio port'
>
>  If yes, skip to 10.
>
>  2. If not, download utility to enable audio port.
>
>  wget http://www.speakeasy.org/~xyzzy/download/cx88_eeprom
>  wget http://www.speakeasy.org/~xyzzy/download/pchdtv_audio
>
>  3. Make them executable
>
>  chmod +x cx88_eeprom pchdtv_audio
>
>  4. Make sure i2c-dev is loaded.
>
>  lsmod | grep i2c-dev
>
>  If yes, skip to step 6
>
>  5. Load i2c-dev
>
>  sudo modprobe i2c-dev
>
>  6. Run the script
>
>  sudo ./pchdtv_audio
>
>  If it succeeded, skip to 8.
>
>  7. If not, run the utility manually
>
>  If the script failed like this:
>
>  Found CX88 Card 0 on I2C bus 2
>  Unable to open file /sys/class/i2c-dev/i2c-2/device/subsystem_vendor: No
>  such file or directory at ./pchdtv_audio line 27.
>
>  then just run cx88_eeprom manually. Copy the bus number from above
>  (in this case "2" (from "bus 2")) to the end of this line (replace the
>  (second) "2" in "i2c-2".)
>
>  sudo ./cx88_eeprom /dev/i2c-2
>
>  If *that* doesn't succeed, I don't know what to say
>  except you probably shouldn't proceed. As I understand
>  things, pcHDTV will happily exchange the tuner for one
>  with the audio port enabled.
>
>  8. Reboot
>
>  9. Make sure the audio port is enabled.
>
>  lspci | grep -i 'audio port'
>
>  10. Make sure cx88-alsa is loaded.
>
>  lspci | grep cx88_alsa
>
>  If yes, skip to 12. Mine was loaded automatically.
>
>  11. If not, load cx88-alsa
>
>  sudo modprobe cx88-alsa
>
>  12. Find your new interface.
>
>  ls /dev/dsp*
>
>  There should be a new either /dev/dsp1 or /dev/dsp2
>  (or something else ?). Remember its name.
>
>  13. Start up mythtv-setup
>
>  14. Go to Capture cards
>
>  15. Select your pcHDTV card.
>
>  16. Enable the analog half
>
>  Assuming that your card type is DVB, there should be
>  a button in the middle that says something like
>  "analog" or "video4linux" (I forget). Select it.
>
>  In the next screen, change where it says "/dev/dsp"
>  to the new /dev/dsp* that you found above.
>
>  IIRC, this is also one of the places that you need
>  to change the audio sampling rate to 48000.
>
>  11. Exit and go to 'Sources'
>
>  12. Add a source called 'Analog' (or whatever you like)
>
>  I did NOT assign a scanner to mine, even though I have
>  Schedules Direct. Re-using my existing Source did not work.
>
>  Theoretically, you can create a second account to assign
>  to your analog signal but I can't confirm this.
>
>  13. Exit and go to Inputs (?)
>
>  You should now see 4 inputs where you used to see 1
>  (more if you have more tuners). The new ones should be:
>
>  Analog->Television
>  Analog->Composite
>  Analog->S-Video
>
>  (Note: this is for the HD3000. Maybe the HD5500 is different.)
>
>  14. Select Analog->Television
>
>  15. Click "Scan for channels"
>
>  It should start scanning and finding channels.
>
>  16. When its done, exit and go to channel editor.
>
>  17. Change the name of the new channels from "Adding new channel"
>  (or whatever it is) to something like "Analog 7" or "KABC NTSC",
>  whatever you like.
>
>  18. Exit mythtv-setup and start mythfrontend
>
>  19. Go into 'Settings'
>
>  20. Go into 'TV settings'
>
>  21. Go into 'Recording profiles'
>
>  22. Go into 'Software encoders (v4l based)'
>
>  23. Go into 'Default'
>
>  24. Change the audio rate to 48000
>
>  25. Exit and also do the same in Live TV, High quality and Low quality
>
>  26. Exit all the way out and 'Watch TV'
>
>  Enjoy the new channels, and notice how crappy analog is
>  compared to digital. ;)
>
>  For the record, I still see massive stuttering on
>  analog channels. I suspect that its because the system
>  can't keep up with the bitrate. (My CPU is only a little
>  over 50%.)
>
>  I'm hoping that when I record a show and transcode it
>  to MPEG2, that it will play nicely after that. If anyone
>  has a better suggestion, would love to hear it.
>
>  Also, if anyone knows that it will work with Schedules
>  Direct, it would be nice to know how to do it.

I tried this method and was able to turn on Audio Port in my HD-3000.
However it seemed to take over my sound card causing any attempt to
play sound to give this error:

mplayer:
[AO_ALSA] alsa-lib: pcm_dmix.c:864:(snd_pcm_dmix_open) unable to open slave
[AO SDL] Unable to open audio: No available audio device

frontend
2008-03-22 18:14:08.840 Opening audio device 'default'. ch 6(2) sr 44100
2008-03-22 18:14:08.841 Opening ALSA audio device 'default'.
ALSA lib pcm_dmix.c:864:(snd_pcm_dmix_open) unable to open slave
2008-03-22 18:14:08.912 AudioOutput Error: snd_pcm_open(default): No
such file or directory

Using the script to toggle Audio Port to off restored sound.  Any ideas?