[alsa-devel] [PATCH 0/2] prescript
Hall all,
here is small patchset for usb devices with wrong volume resolution. First one add warning if too big resolution is found. Second adds quirk for one more webcam.
For more info see patch a5c7d797dcce3be5e77cd6ea62cc4920ededc32b
Author: Alexey Fisher bug-track@fisher-privat.net Date: Wed Jun 23 14:17:09 2010 +0200 ALSA: usb-audio - Add volume resolution quirk for some Logitech webcams
....
Regards, Alexey
Se comment in patch: a5c7d797dcce3be5e77cd6ea62cc4920ededc32b ALSA: usb-audio - Add volume resolution quirk for some Logitech webcams
Signed-off-by: Alexey Fisher bug-track@fisher-privat.net --- sound/usb/mixer.c | 15 +++++++++++++++ 1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 85af605..eba8ae8 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -987,6 +987,7 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc, struct snd_kcontrol *kctl; struct usb_mixer_elem_info *cval; const struct usbmix_name_map *map; + unsigned int range;
control++; /* change from zero-based to 1-based value */
@@ -1136,6 +1137,20 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
}
+ range = (cval->max - cval->min) / cval->res; + /* Are there devices with volume range more than 255? I use a bit more + * to be sure. 384 is a resolution magick nuber found on Logitech + * devices. It will definitively catch all buggy Logitech devices. */ + if (range > 384) { + snd_printk(KERN_WARNING "usb_audio: Warning! Unlikely big " + "volume range (=%u), cval->res is probably wrong.", + range); + snd_printk(KERN_WARNING "usb_audio: [%d] FU [%s] ch = %d, " + "val = %d/%d/%d", cval->id, + kctl->id.name, cval->channels, + cval->min, cval->max, cval->res); + } + snd_printdd(KERN_INFO "[%d] FU [%s] ch = %d, val = %d/%d/%d\n", cval->id, kctl->id.name, cval->channels, cval->min, cval->max, cval->res); add_control_to_empty(state, kctl);
One more affected devices: Logitech Webcam C600 (046d:0808)
Volume range before quirk is 6400, after (also real) is 16.
Signed-off-by: Alexey Fisher bug-track@fisher-privat.net --- sound/usb/mixer.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index eba8ae8..c549522 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1122,6 +1122,7 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc, } break;
+ case USB_ID(0x046d, 0x0808): case USB_ID(0x046d, 0x0809): case USB_ID(0x046d, 0x0991): /* Most audio usb devices lie about volume resolution.
2011/3/10 Alexey Fisher bug-track@fisher-privat.net
One more affected devices: Logitech Webcam C600 (046d:0808)
Volume range before quirk is 6400, after (also real) is 16.
Signed-off-by: Alexey Fisher bug-track@fisher-privat.net
sound/usb/mixer.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index eba8ae8..c549522 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1122,6 +1122,7 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc, } break;
case USB_ID(0x046d, 0x0808): case USB_ID(0x046d, 0x0809): case USB_ID(0x046d, 0x0991): /* Most audio usb devices lie about volume resolution.-- 1.7.1
It is because each step of usb audio is 1/256dB , so 384 step is 1.5dB
Is there any way to verify the resolution is 1.5dB ?
since alsamixertest does not check the capture volume (only check the playback volume)
And mindB +18dB and maxdB +30dB , It can still record sound using audacity at +18dB , so it seem break the pulseaudio developer 's assumption that 0% is -infinite dB
state.U0x46d0x992 { control.1 { iface MIXER name 'Mic Capture Switch' value false comment { access 'read write' type BOOLEAN count 1 } } control.2 { iface MIXER name 'Mic Capture Volume' value 3072 comment { access 'read write' type INTEGER count 1 range '0 - 3072' dbmin 1800 dbmax 3000 dbvalue.0 3000 } } }
At Thu, 10 Mar 2011 14:53:37 +0100, Alexey Fisher wrote:
Hall all,
here is small patchset for usb devices with wrong volume resolution. First one add warning if too big resolution is found. Second adds quirk for one more webcam.
For more info see patch a5c7d797dcce3be5e77cd6ea62cc4920ededc32b
Author: Alexey Fisher bug-track@fisher-privat.net Date: Wed Jun 23 14:17:09 2010 +0200 ALSA: usb-audio - Add volume resolution quirk for some Logitech webcams
....
Thanks. Applied both patches now (with typo fixes).
Takashi
participants (3)
-
Alexey Fisher -
Raymond Yau -
Takashi Iwai