Native Development

[guru2000at]

Preferred PCM vs Other PSM

while i was investigating how to record sound and some other sound regarding issues, i came across:
https://bdsc.webapps.blackberry.com/native/reference/com.qnx.doc.neutrino.audio/topic/architecture_c...

so i was interested in the last part of hte documention:
"You can list the devices that are on your system by typing:

ls /dev/snd"

i investigated this point and here is the output:

$ ls -la /dev/snd
total 0
-rw-rw-rw-   1 root      nto               0 Jan 04 12:27 controlC0
-rw-rw-rw-   1 root      nto               0 Jan 03 18:16 mixerC0D0
-rw-rw-rw-   1 root      nto               0 Jan 04 11:09 pcmC0D0c
-rw-rw-rw-   1 root      nto               0 Jan 04 12:27 pcmC0D0p
-rw-rw-rw-   1 root      nto               0 Jan 03 18:17 pcmC0D1p
-rw-rw-rw-   1 root      nto               0 Jan 04 12:27 pcmC0D2p
-rw-rw-rw-   1 root      nto               0 Jan 04 12:27 pcmC0D3p
-rw-rw-rw-   1 root      nto               0 Jan 04 12:27 pcmC0D4c
-rw-rw-rw-   1 root      nto               0 Jan 04 12:27 pcmC0D5c
-rw-rw-rw-   1 root      nto               0 Jan 04 12:27 pcmC0D5p
-rw-rw-rw-   1 root      nto               0 Jan 04 12:27 pcmC0D6c
lrw-rw-rw-   1 root      nto               0 Jan 04 12:27 pcmPreferredc -> pcmC0D0c
lrw-rw-rw-   1 root      nto               0 Jan 04 12:27 pcmPreferredp -> pcmC0D1p

an image in the docu show pcmC0D0p as some kind of "standard" pcm, but the preferred is linked to pcmC0D1p.

does anybody know why ?

[gbeukeboom · Accepted solution]

Hi,

The diagram in the linked site is just a generic diagram of audio devices and does not reflect the preferred PCM. To determine the preferred PCM you have a few options:
Synchronously - use

audiodevice_get()

 Asynchronously - call

audiodevice_request_events() 

Before your BPS loop then check for audio change events using

 audiodevice_event_get_path()

Regards,

[guru2000at]

thx for the clarification