Mailing List Archive

>I've finally gotten mythtv setup and running with
>capture using the following equipment:
>Asus A7A333 (Think thats right)
>CM8738 onboard sound
>WinTv Go
>Athlon 1700+
>256Mb Ram
>
>Systems encode and decodes the video just fine, but
>the audio is just crap. Hissing and low volume.
>I've messed with the levels in ALSA mixer for an hour
>or two to no avail. Then I moved the sound feed from
>line-in to mic-in after reading a post. That did
>nothing as well. I also tried all three encoding
>levels. No discernable difference in sound quality
>either. Below I've provided some info that might
>help. If anyone has any ideas I'd be happy to hear
>them!

maybe try using /dev/adsp instead of /dev/dsp? It seems
to have helped my AC97.

Kevin Hjelden wrote:

>
>> I've finally gotten mythtv setup and running with
>> capture using the following equipment:
>> Asus A7A333 (Think thats right)
>> CM8738 onboard sound
>> WinTv Go
>> Athlon 1700+
>> 256Mb Ram
>>
>> Systems encode and decodes the video just fine, but
>> the audio is just crap. Hissing and low volume.
>> I've messed with the levels in ALSA mixer for an hour
>> or two to no avail. Then I moved the sound feed from
>> line-in to mic-in after reading a post. That did
>> nothing as well. I also tried all three encoding
>> levels. No discernable difference in sound quality
>> either. Below I've provided some info that might
>> help. If anyone has any ideas I'd be happy to hear
>> them!
>
>
> maybe try using /dev/adsp instead of /dev/dsp? It seems
> to have helped my AC97.
>

Or try using /dev/sound/dsp, that worked for me. I don't remember why
/dev/dsp didn't work, though. Wasn't bad sound quality.


Pete

I had similar issues with sound. I had setup to record line in, and
could not figure out why the sound was hissing and distorted. It sounded
like it was being over amplified. I just started playing around with
alsamixer and found that I had a 'AC97' and 'AC97 Cap'. I had to turn
down the AC97, and turn up AC97 Cap.

Cheers...

-----Original Message-----
From: mythtv-users-bounces@snowman.net
[mailto:mythtv-users-bounces@snowman.net] On Behalf Of Christopher Ferry
Sent: Sunday, May 18, 2003 11:25 AM
To: mythtv-users@snowman.net
Subject: [mythtv-users] Poor sound quality cmipci


I've finally gotten mythtv setup and running with
capture using the following equipment:
Asus A7A333 (Think thats right)
CM8738 onboard sound
WinTv Go
Athlon 1700+
256Mb Ram

Systems encode and decodes the video just fine, but
the audio is just crap. Hissing and low volume.
I've messed with the levels in ALSA mixer for an hour
or two to no avail. Then I moved the sound feed from
line-in to mic-in after reading a post. That did
nothing as well. I also tried all three encoding
levels. No discernable difference in sound quality
either. Below I've provided some info that might
help. If anyone has any ideas I'd be happy to hear
them!

Thanks

Chris


<-- Snippet from /proc/pci -->
Bus 0, device 5, function 0:
Multimedia audio controller: C-Media Electronics
Inc CM8738 (rev 16).
IRQ 10.
Master Capable. Latency=32. Min Gnt=2.Max
Lat=24.
I/O at 0xa000 [0xa0ff].
Bus 0, device 9, function 0:
Ethernet controller: Lite-On Communications Inc
LNE100TX (rev 32).
IRQ 10.
Master Capable. Latency=32.
I/O at 0x9800 [0x98ff].
Non-prefetchable 32 bit memory at 0xe6000000 [0xe60000ff].
Bus 0, device 11, function 0:
Multimedia video controller: Brooktree Corporation
Bt878 Video Capture (rev 17).
IRQ 5.
Master Capable. Latency=32. Min Gnt=16.Max
Lat=40.
Prefetchable 32 bit memory at 0xef000000
[0xef000fff].
Bus 0, device 11, function 1:
Multimedia controller: Brooktree Corporation Bt878
Audio Capture (rev 17).
IRQ 5.
Master Capable. Latency=32. Min Gnt=4.Max
Lat=255.
Prefetchable 32 bit memory at 0xee800000
[0xee800fff].
Bus 1, device 0, function 0:
<-- End pci snippet -->
<-- Begin lsmod output -->
bash-2.05b$ /sbin/lsmod
Module Size Used by Not tainted
isofs 27988 1 (autoclean)
zlib_inflate 21156 0 (autoclean) [isofs]
udf 90464 0 (autoclean)
radeon 108484 23
agpgart 40896 3 (autoclean)
autofs4 11540 2 (autoclean)
parport_pc 25096 1 (autoclean)
lp 8096 0 (autoclean)
parport 34176 1 (autoclean)
[parport_pc lp]
nls_cp437 5148 3 (autoclean)
nls_iso8859-1 3516 4 (autoclean)
smbfs 40144 3 (autoclean)
snd-seq-midi 5024 0 (autoclean) (unused)
snd-opl3-synth 12548 0 (autoclean) (unused)
snd-seq-instr 7172 0 (autoclean)
[snd-opl3-synth]
snd-seq-midi-emul 6780 0 (autoclean)
[snd-opl3-synth]
snd-ainstr-fm 2912 0 (autoclean)
[snd-opl3-synth]
snd-seq-oss 31104 0 (unused)
snd-seq-midi-event 5640 0 [snd-seq-midi
snd-seq-oss]
snd-seq 42608 2 [snd-seq-midi
snd-opl3-synth snd-seq-instr snd-seq-midi-emul
snd-seq-oss snd-seq-midi-event]
snd-pcm-oss 43556 0
snd-mixer-oss 14488 0 [snd-pcm-oss]
snd-cmipci 23200 0
snd-pcm 77536 0 [snd-pcm-oss
snd-cmipci]
snd-page-alloc 7732 0 [snd-pcm]
snd-opl3-lib 8036 0 [snd-opl3-synth
snd-cmipci]
snd-timer 18376 0 [snd-seq snd-pcm
snd-opl3-lib]
snd-hwdep 6368 0 [snd-opl3-lib]
snd-mpu401-uart 4396 0 [snd-cmipci]
snd-rawmidi 17600 0 [snd-seq-midi
snd-mpu401-uart]
snd-seq-device 5832 0 [snd-seq-midi
snd-opl3-synth snd-seq-oss snd-seq snd-opl3-lib
snd-rawmidi]
snd 40868 0 [.snd-seq-midi
snd-opl3-synth snd-seq-instr snd-seq-oss
snd-seq-midi-event snd-seq snd-pcm-oss snd-mixer-oss
snd-cmipci snd-pcm snd-opl3-lib snd-timer snd-hwdep snd-mpu401-uart
snd-rawmidi snd-seq-device]
nfsd 74256 8 (autoclean)
af_packet 14952 2 (autoclean)
sr_mod 16920 0 (autoclean)
tulip 44032 1 (autoclean)
supermount 15296 2 (autoclean)
reiserfs 190736 1 (autoclean)
ide-cd 33856 2
cdrom 31648 0 [sr_mod ide-cd]
tvaudio 15068 0 (autoclean) (unused)
bttv 78496 0
videodev 7872 2 [bttv]
i2c-algo-bit 9064 1 [bttv]
soundcore 6276 0 [snd bttv]
ide-scsi 11280 0
scsi_mod 103284 2 [sr_mod ide-scsi]
tuner 11744 1
i2c-core 21192 0 [tvaudio bttv
i2c-algo-bit tuner]
ati_remote 6424 0 (unused)
evdev 5632 0 (unused)
usbmouse 2936 0 (unused)
usbkbd 4440 0 (unused)
keybdev 2720 0 (unused)
mousedev 5268 0 (unused)
hid 20900 0 (unused)
input 5664 0 [ati_remote evdev
usbmouse usbkbd keybdev mousedev hid]
usb-ohci 20584 0 (unused)
usbcore 72992 1 [ati_remote usbmouse
usbkbd hid usb-ohci]
rtc 8060 0 (autoclean)
xfs 434546 6
<-- End lsmod -->

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I have onboard CMI 8738 sound, and had the same crappy, hissing sound (only
when using Myth). I think the problem was (partially) that the card was only
able to do 8-bit sound in full duplex mode. I finally gave up once I
realized my capture card (WinTV-radio 401) could do btaudio. Good luck.

-JAC

On Sunday 18 May 2003 02:24 pm, Christopher Ferry wrote:
> I've finally gotten mythtv setup and running with
> capture using the following equipment:
> Asus A7A333 (Think thats right)
> CM8738 onboard sound
> WinTv Go
> Athlon 1700+
> 256Mb Ram
>
> Systems encode and decodes the video just fine, but
> the audio is just crap. Hissing and low volume.
> I've messed with the levels in ALSA mixer for an hour
> or two to no avail. Then I moved the sound feed from
> line-in to mic-in after reading a post. That did
> nothing as well. I also tried all three encoding
> levels. No discernable difference in sound quality
> either. Below I've provided some info that might
> help. If anyone has any ideas I'd be happy to hear
> them!
>
> Thanks
>
> Chris