2010/6/23 Colin Guthrie gmane@colin.guthr.ie
'Twas brillig, and Raymond Yau at 23/06/10 02:15 did gyre and gimble:
why PA server still insist to open front device for capturing ?
Couldn't tell you. Perhaps Lennart is unaware that it is considered invalid? I'll ask him.
http://thread.gmane.org/gmane.linux.alsa.devel/67912/focus=68248
As Takashi had already mention that
"I agree that the capture from "front" PCM isn't considered as valid. The "front", "rear", "center_lfe" definitions are rather for
multi-channel
playbacks. The capture on these channels aren't useful in most cases."
you can perform an experiement
pcm.test { type softvol slave.pcm "hw:0,0" control { name "PA Playback Volume" card 0 }
arecord -D test -f CD -d 10 -v test.wav
you will find "PA Playback Volume" in playback screen of alsamixer
I am not sure the softvol control created when PA open front device for playback and capture is used for playback or capture
BTW , PA still using "front" to open CTL device too
You'll have to ask Lennart directly about that bit.
arecord -Dfront:0 -v -f cd | aplay -Dfront:0 -v -f cd
the softvol control was seem to used by arecord and aplay concurrently
Using front device for capture 1) HDA, the problem is softvol plugin, 2) emu10k1 , the problem is the hook controls in front playback device which change the route of volume of the DSP hardware mixer 3)
I can't speak for him with regards to the full setup of the mixer path probing stuff, so perhaps "front" should be edited out of this for paths. It would likely be a fairly trivial change to configuration files rather than any code changes.
Col
Well , He had already hardcoded to use "hw:card_number" in dbverify.c , it is only PA server still try to open mixer device "front"
The tooltip of gnome volume control in Fedora 13 clearly indiacte that 100% is 0dB for intel8x0 which use ac97 codec when you put the cursor on top of the speaker icon at the system bar
https://bugzilla.gnome.org/show_bug.cgi?id=618551
according to gnome-media-developer Bastien Nocera
In any case, we only display what PulseAudio tells us, so you should poke the PulseAudio devs about this.
This is the code in question: gdouble gvc_mixer_stream_get_decibel (GvcMixerStream *stream) { g_return_val_if_fail (GVC_IS_MIXER_STREAM (stream), 0);
return pa_sw_volume_to_dB( (pa_volume_t) gvc_channel_map_get_volume(stream->priv->channel_map)[VOLUME]); }
if you don't have any ac97 sound card , you can user virtualbox which has an emulated intel8x0 sound card