[alsa-devel] concept of substream...
Hi,
I was trying to understand the concept of substream. So can we have a device which can have support say 5 substreams and these are controlled (start/stop) independent of each other. At any instance we can have any number of substreams active and runtime we should be able to activate/deactivate a particular substream. Is that doable with this concept or should i look at something else?
-- ~Vinod
Vinod Koul wrote:
I was trying to understand the concept of substream. So can we have a device which can have support say 5 substreams and these are controlled (start/stop) independent of each other.
Yes.
At any instance we can have any number of substreams active and runtime we should be able to activate/deactivate a particular substream.
If by "active" you mean opened or running, yes.
Please note that when opening a device without specifying a substream number, ALSA will open the first free one. This implies that all substreams should go the same output (i.e., be mixed together).
Regards, Clemens
At Wed, 08 Feb 2012 14:56:02 +0530, Vinod Koul wrote:
On Wed, 2012-02-08 at 10:16 +0100, Clemens Ladisch wrote:
Vinod Koul wrote:
I was trying to understand the concept of substream. So can we have a device which can have support say 5 substreams and these are controlled (start/stop) independent of each other.
Yes.
At any instance we can have any number of substreams active and runtime we should be able to activate/deactivate a particular substream.
If by "active" you mean opened or running, yes.
Please note that when opening a device without specifying a substream number, ALSA will open the first free one. This implies that all substreams should go the same output (i.e., be mixed together).
Mixed in alsa or should be mixed by device?
It's pretty much depending on the hardware and the driver implementation.
Takashi
On Wed, 2012-02-08 at 10:16 +0100, Clemens Ladisch wrote:
Vinod Koul wrote:
I was trying to understand the concept of substream. So can we have a device which can have support say 5 substreams and these are controlled (start/stop) independent of each other.
Yes.
At any instance we can have any number of substreams active and runtime we should be able to activate/deactivate a particular substream.
If by "active" you mean opened or running, yes.
Please note that when opening a device without specifying a substream number, ALSA will open the first free one. This implies that all substreams should go the same output (i.e., be mixed together).
Mixed in alsa or should be mixed by device?
On Wed, 2012-02-08 at 10:25 +0100, Takashi Iwai wrote:
Please note that when opening a device without specifying a
substream
number, ALSA will open the first free one. This implies that all substreams should go the same output (i.e., be mixed together).
Mixed in alsa or should be mixed by device?
It's pretty much depending on the hardware and the driver implementation.
okay does it means its fair assumption that in driver I will get 5 opens/5 buffers. And driver is tasked with routing them to respective output?
At Wed, 08 Feb 2012 15:03:47 +0530, Vinod Koul wrote:
On Wed, 2012-02-08 at 10:25 +0100, Takashi Iwai wrote:
Please note that when opening a device without specifying a
substream
number, ALSA will open the first free one. This implies that all substreams should go the same output (i.e., be mixed together).
Mixed in alsa or should be mixed by device?
It's pretty much depending on the hardware and the driver implementation.
okay does it means its fair assumption that in driver I will get 5 opens/5 buffers. And driver is tasked with routing them to respective output?
Yes.
Takashi
participants (3)
-
Clemens Ladisch -
Takashi Iwai -
Vinod Koul