[mythtv-users] snd-bt87x dsp : was snd-bt87x not detected?
Eric Hattemer
eric at hattenator.dyndns.org
Wed Aug 23 07:56:18 UTC 2006
Eric Hattemer wrote:
>
> With neither the btaudio nor snd-bt87x modules loaded, I can hear faint
> sound if I crank the volume up. I believe I need something to turn the
> CD-size output on the card on. I believe what I need is for snd-bt87x
> to create an alsa card that I can control the volume on.
>
> Fedora 5 dropped all OSS. There is no btaudio. With bt878 and
> snd_bt87x and the CD input cranked all the way up, I could hear some
> tiny sound. I compiled my own kernel. I modprobed btaudio without
> snd-bt87x. I connected mythtv-setup to /dev/dsp1 (never remember doing
> that before). I managed to get good volume audio, but the video files
> are not synchronized with audio and video anymore, and the audio
> repeats/chops.
>
>
> I am currently compiling the btaudio module into fedora 5's
> 2.6.17-1.2174_FC5 kernel to see if it is less choppy. If you have an
> ATi TV wonder and are running fedora5, please let me know how your
> modprobe.conf and your lsmod looks, and which device you have
> mythtv-setup using.
>
>
So I've been working on this lately and haven't gotten much farther. I
put a whole ton of lines into my modprobe.conf without really affecting
anything. One thing I learned is that with snd_bt87x, the alsa
recording of the tv sound works fine:
arecord -D hw:1,1 -f S16_LE -t wav test.wav
However, the sox recording of the dsp doesn't make any noise but a
slight hiss:
sox -w -r 32000 -t ossdsp /dev/dsp1 -t ossdsp /dev/dsp
So I think its a modprobe.conf issue or a snd_pcm_oss kind of issue.
Basically if ALSA:1,1 works, but /dev/dsp1 doesn't, its probably an
ALSA-oss translation issue, right?
I changed modprobe.conf around and cut part into modprobe.d/tv. For
some reason snd_bt87x module doesn't load on boot anymore. I don't
understand modprobe or udev or how modules are loaded very well. This
is my new modprobe.d/tv file:
alias char-major-81 bttv
options char-major-81 card=63 gbuffers=4 automute=0 tuner=2
alias tuner0 tuner
# ALSA portion
alias char-major-116 snd
alias snd-card-1 snd-bt87x
options snd-card-1 index=1 load_all=1
# module options should go here
# OSS/Free portion
alias char-major-14 soundcore
# card #1
# OSS/Free portion - card #1
alias sound-slot-0 snd-card-0
alias sound-service-0-0 snd-mixer-oss
alias sound-service-0-1 snd-seq-oss
alias sound-service-0-3 snd-pcm-oss
alias sound-service-0-8 snd-seq-oss
alias sound-service-0-12 snd-pcm-oss
# OSS/Free portion - card #2 (cmipci)
alias sound-slot-1 snd-card-1
alias sound-service-1-0 snd-mixer-oss
alias sound-service-1-3 snd-pcm-oss
alias sound-service-1-12 snd-pcm-oss
#alias sound-slot-1 snd-bt87x
#alias sound-service-1-0 snd-bt87x
#alias sound-slot-2 btaudio
#alias sound-service-2-0 btaudio
-Eric Hattemer
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