[alsa-devel] Selecting correct input device port.
As I learn't in this mailng list, a device can typically handle only one stream at a time unless it supports hardware mixing which's exposed via subdevices in ALSA
What does subdevice mean for input device? Do they mark physical ports for input? If not how do I record from a specific input port? Is it automatically selected by the card?
And what's 'input source' in ALSA mixer?
On 10/28/14 09:57, dE wrote:
As I learn't in this mailng list, a device can typically handle only one stream at a time unless it supports hardware mixing which's exposed via subdevices in ALSA
What does subdevice mean for input device? Do they mark physical ports for input? If not how do I record from a specific input port? Is it automatically selected by the card?
And what's 'input source' in ALSA mixer?
Pointers to any doc...?
At Tue, 28 Oct 2014 09:57:18 +0530, dE wrote:
As I learn't in this mailng list, a device can typically handle only one stream at a time unless it supports hardware mixing which's exposed via subdevices in ALSA
What does subdevice mean for input device?
When a device can do multiplexing, the driver can give multiple substreams (= subdevices).
Do they mark physical ports for input? If not how do I record from a specific input port?
You can pass the subdevice number explicity. It's -1 as default, which means to select the next free one.
Is it automatically selected by the card?
And what's 'input source' in ALSA mixer?
It's usually a MUX to select the input source, e.g. line in or mic.
Takashi
On 10/29/14 13:06, Takashi Iwai wrote:
At Tue, 28 Oct 2014 09:57:18 +0530, dE wrote:
As I learn't in this mailng list, a device can typically handle only one stream at a time unless it supports hardware mixing which's exposed via subdevices in ALSA
What does subdevice mean for input device?
When a device can do multiplexing, the driver can give multiple substreams (= subdevices).
Do they mark physical ports for input? If not how do I record from a specific input port?
You can pass the subdevice number explicity. It's -1 as default, which means to select the next free one.
Is it automatically selected by the card?
And what's 'input source' in ALSA mixer?
It's usually a MUX to select the input source, e.g. line in or mic.
Takashi
Input source for single subdevice right? I've 3 sub device, does it have to do anything with the fact that I've 3 input source in alsamixer? Do the 3 input source mark 3 different subdevices?
By muxing you mean muxing via software the multiple individual (and simultaneous) audio input streams as supported by the cards?
2014-10-30 下午12:38 於 "dE" de.techno@gmail.com 寫道：
On 10/29/14 13:06, Takashi Iwai wrote:
At Tue, 28 Oct 2014 09:57:18 +0530, dE wrote:
As I learn't in this mailng list, a device can typically handle only one stream at a time unless it supports hardware mixing which's exposed via subdevices in ALSA
What does subdevice mean for input device?
When a device can do multiplexing, the driver can give multiple substreams (= subdevices).
Do they mark physical ports for input? If not how do I record from a specific input port?
You can pass the subdevice number explicity. It's -1 as default, which means to select the next free one.
Is it automatically selected by the card?
And what's 'input source' in ALSA mixer?
It's usually a MUX to select the input source, e.g. line in or mic.
Input source for single subdevice right? I've 3 sub device, does it have
to do anything with the fact that I've 3 input source in alsamixer? Do the 3 input source mark 3 different subdevices?
So far, only those 10 channel hda codecs have three ADC
Due to recent change in snd-hda-intel, if your desktop previously had three subdevices, the new driver create analog capture device with one subdevice and alt analog capture with two subdevices
On 10/30/14 11:12, Raymond Yau wrote:
2014-10-30 下午12:38 於 "dE" <de.techno@gmail.com mailto:de.techno@gmail.com> 寫道：
On 10/29/14 13:06, Takashi Iwai wrote:
At Tue, 28 Oct 2014 09:57:18 +0530, dE wrote:
As I learn't in this mailng list, a device can typically handle
only one
stream at a time unless it supports hardware mixing which's
exposed via
subdevices in ALSA
What does subdevice mean for input device?
When a device can do multiplexing, the driver can give multiple substreams (= subdevices).
Do they mark physical ports for input? If not how do I record from a specific input port?
You can pass the subdevice number explicity. It's -1 as default, which means to select the next free one.
Is it automatically selected by the card?
And what's 'input source' in ALSA mixer?
It's usually a MUX to select the input source, e.g. line in or mic.
Input source for single subdevice right? I've 3 sub device, does it
have to do anything with the fact that I've 3 input source in alsamixer? Do the 3 input source mark 3 different subdevices?
So far, only those 10 channel hda codecs have three ADC
Due to recent change in snd-hda-intel, if your desktop previously had three subdevices, the new driver create analog capture device with one subdevice and alt analog capture with two subdevices
Thanks for clarifying everyone!
Looks like my mobo is bad.
As I learn't in this mailng list, a device can typically handle only one
stream at a time unless it supports hardware mixing which's exposed via subdevices in ALSA
What does subdevice mean for input device? Do they mark physical ports
for input? If not how do I record from a specific input port? Is it automatically selected by the card?
And what's 'input source' in ALSA mixer?
'Input source' usually found in those desktop using hda codec with two or more ADC since hda support multistreaming
Most sound card only support one analog capture device with 'Capture Source' control
Most notebook with hda codec have auto mic enabled by default, the capture source is determined by jack detection
participants (3)
-
dE -
Raymond Yau -
Takashi Iwai