Hi,
On 10.07.2012 07:25, Gordon Dilan wrote:
I'm using an usb mic which(according to it's producer should support up to 48kHz sampling rate). The problem is ALSA allows me to use only 16 kHz for this device. I do not want to resample the data, I want to sample it at 48kHz in order to be able to record some high pitch sounds 18-20kHz.
I would want to try to do any modifications necessary in order to try support 48kHz, but I'm not sure where to start.
[...]
Some more information: lsusb Bus 001 Device 007: ID 1415:2000 Nam Tai E&E Products Ltd. or OmniVision Technologies, Inc. Sony Playstation Eye
lsusb -t
Please also provide the output of 'lsusb -v'.
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/2p, 480M |__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/6p, 480M |__ Port 2: Dev 7, If 0, Class=vend., Driver=ov534, 480M |__ Port 2: Dev 7, If 1, Class=audio, Driver=snd-usb-audio, 480M |__ Port 2: Dev 7, If 2, Class=audio, Driver=snd-usb-audio, 480M
At the moment I'm looking inside ALSA's source code to try to see from where this limitation of 16000kHz for my device appears, but I have to admit that I'm kind of lost. Any pointers on what direction should I go to try make my desired rate supported would be greatly appreciated!
The device is queried for its supported sample rates during probe using class-specific commands. If it doesn't return all rates that are actually supported, we need to add a quirk and override this list.
The list of known sample rates is included in /proc/asound/card1/stream0. What does that show for you?
Daniel