Takashi Iwai wrote:
> At Tue, 13 Feb 2007 18:36:35 +0100,
> Karsten Wiese wrote:
>> Hi Rui,
>>
>> Am Dienstag, 13. Februar 2007 schrieb Rui Nuno Capela:
>>> Hi Karsten,
>>>
>>> In my quest in completing us428control implementation, I'm now stumbling
>>> on a fundamental question regarding the number of tracks/channel-faders
>>> (per bank) each particular usx2y device supports. The question boils down
>>> to what is the actual numeric value of the y in the actual usx2y model
>>> name :)
>>>
>>> In practice, I need to know which usx2y model is actually connected.
>>>
>>> So, what is the best/deterministic way to detect (programmatically)
>>> whether us428control is connecting to a US224 (y=4, as mine) _or_ a US428
>>> (y=8, as yours) ?
>>>
>>> Is snd_hwdep_info_get_name() expected to be the most correct method?
>> Yes, I fear. this gives the /proc/bus/usb/002/004 filename.
>> I just did cat /proc/bus/usb/004/005 > x
>> and check x with hexedit: the 1604 and 8001 is in there.
>> I don't know how to portably interpret a read from
>> /proc/bus/usb/004/005 though.
>
> Note that /proc/bus/usb is deprecated on many distros...
>
How about using snd_pcm_hw_params_get_channels_max() ?
At least on capture the US224 should give 2 and the US428 should give 4
as the maximum number of channels.
It would be handful for me if the attached test program could be ran
against a US428, just for the records ;)
On my US224 it gives:
$ snd_hwdep_info hw:3
---hwdep---
snd_hwdep_info_get_id (hw:3) = 'USX2Y Loader'
snd_hwdep_info_get_name (hw:3) = '/proc/bus/usb/001/004'
---pcm (capture)---
snd_pcm_hw_params_get_channels_min(hw:3) = 2
snd_pcm_hw_params_get_channels_max(hw:3) = 2
---pcm (playback)---
snd_pcm_hw_params_get_channels_min(hw:3) = 2
snd_pcm_hw_params_get_channels_max(hw:3) = 2
Karsten?
--
rncbc aka Rui Nuno Capela
rncbc@xxxxxxxxx
#include <stdio.h>
#include <stdlib.h>
#include <alsa/asoundlib.h>
/**
Vendor / Product ID
0x1604 / 0x8001 (US428)
0x1604 / 0x8005 (US224)
0x1604 / 0x8007 (US122)
*/
int print_hwdep_info ( const char *name )
{
snd_hwdep_t *hwdep = NULL;
snd_hwdep_info_t *hwdep_info;
int err;
if ((err = snd_hwdep_open(&hwdep, name,
SND_HWDEP_OPEN_READ | SND_HWDEP_OPEN_NONBLOCK)) < 0) {
fprintf(stderr, "snd_hwdep_open(%s): %s\n", name, snd_strerror(err));
return err;
}
snd_hwdep_info_alloca(&hwdep_info);
if ((err = snd_hwdep_info(hwdep, hwdep_info)) < 0) {
fprintf(stderr, "snd_hwdep_info(%s): %s\n", name, snd_strerror(err));
} else {
printf("snd_hwdep_info_get_id (%s) = '%s'\n", name, snd_hwdep_info_get_id(hwdep_info));
printf("snd_hwdep_info_get_name (%s) = '%s'\n", name, snd_hwdep_info_get_name(hwdep_info));
}
if ((err = snd_hwdep_close(hwdep)) < 0)
fprintf(stderr, "snd_hwdep_close(%s): %s\n", name, snd_strerror(err));
return err;
}
int print_pcm_info ( const char *name, int stream )
{
snd_pcm_t *pcm;
snd_pcm_hw_params_t *hw_params;
unsigned int channels;
int err;
if ((err = snd_pcm_open(&pcm, name, stream, SND_PCM_NONBLOCK)) < 0) {
fprintf(stderr, "snd_pcm_open(%s): %s\n", name, snd_strerror(err));
return err;
}
snd_pcm_hw_params_alloca(&hw_params);
if ((err = snd_pcm_hw_params_any(pcm, hw_params)) < 0) {
fprintf(stderr, "snd_pcm_hw_params_any(%s): %s\n", name, snd_strerror(err));
} else {
if ((err = snd_pcm_hw_params_get_channels_min(hw_params, &channels)) < 0) {
fprintf(stderr, "snd_pcm_hw_params_get_channels_min(%s): %s\n", name, snd_strerror(err));
} else {
printf("snd_pcm_hw_params_get_channels_min(%s) = %u\n", name, channels);
}
if ((err = snd_pcm_hw_params_get_channels_max(hw_params, &channels)) < 0) {
fprintf(stderr, "snd_pcm_hw_params_get_channels_max(%s): %s\n", name, snd_strerror(err));
} else {
printf("snd_pcm_hw_params_get_channels_max(%s) = %u\n", name, channels);
}
}
if ((err = snd_pcm_close(pcm)) < 0)
fprintf(stderr, "snd_pcm_close(%s): %s\n", name, snd_strerror(err));
return err;
}
int main ( int argc, char *argv[] )
{
int i;
for (i = 1; i < argc; ++i) {
const char *name = argv[i];
printf("---hwdep---\n");
print_hwdep_info(name);
printf("---pcm (capture)---\n");
print_pcm_info(name, SND_PCM_STREAM_CAPTURE);
printf("---pcm (playback)---\n");
print_pcm_info(name, SND_PCM_STREAM_PLAYBACK);
}
}
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