On 2010-09-07 19:06, Clemens Ladisch wrote: > IOhannes m zmoelnig wrote: >> i'm requesting my "plughw" device with 44100Hz >> the request is done with something like: >> rate=44100; >> err = snd_pcm_hw_params_set_rate_min(handle, params, &rate, 0); > > This requests a sample rate of at least 44100 Hz. yes. this is good enough for me. (it shouldn't crash though) > >> [...] >> err = snd_pcm_hw_params(handle, params); >> >> what happens: >> in the snd_pcm_hw_params(), my program exits with: >> "interval_inline.h:52: snd_interval_single: Assertion >> `!snd_interval_empty(i)' failed." > > You called snd_pcm_hw_params with an invalid params structure. > I'd guess that snd_pcm_hw_params_set_rate_min (or some other > snd_pcm_hw_params_set_*) returned an error. i wish you were right. however, it seems like i am blindfolded. i noticed however, that i need to set both the rate (i use snd_pcm_hw_params_set_rate_min()) and the period size (i use snd_pcm_hw_params_set_period_size_near()), in order to make it crash. attached is an example code that triggers the crash. please someone shed some light... gmasdr IOhannes PS: that's how i use the sample program: $ gcc -o alsatest alsatest.c $(pkg-config --cflags --libs alsa) $ ./alsatest trying to open 'hw:0' as CAPTURE configuring device succeeded CAPTURE configured trying to open 'hw:0' as PLAYBACK configuring device succeeded PLAYBACK configured trying to open 'plughw:0' as CAPTURE configuring device succeeded CAPTURE configured trying to open 'plughw:0' as PLAYBACK alsatest: interval_inline.h:55: snd_interval_single: Assertion `!snd_interval_empty(i)' failed. Aborted so it seems to work fine with "hw:0" but not with "plughw:0". you can specify the device to be opened on the cmdline: $ ./alsatest hw:2
#include <stdio.h>
#include <alsa/asoundlib.h>
#define ENABLE_SETPARAMS_RATE 1
#define ENABLE_SETPARAMS_PERIOD 2
/* neither set_rate_min() nor set_period_size_near() is ok (but trivial) */
//#define ENABLE_SETPARAMS 0
/* only set_rate_min() is ok */
//#define ENABLE_SETPARAMS ENABLE_SETPARAMS_RATE
/* only set_period_size_near() is ok as well */
//#define ENABLE_SETPARAMS ENABLE_SETPARAMS_PERIOD
/* both set_rate_min() and set_period_size_near() -> CRASH */
#define ENABLE_SETPARAMS ENABLE_SETPARAMS_RATE | ENABLE_SETPARAMS_PERIOD
int pcm_configure(snd_pcm_t *pcm) {
unsigned int rate=44100;
snd_pcm_uframes_t uframes = 64;
snd_pcm_hw_params_t* hw_params;
int err;
snd_pcm_hw_params_alloca(&hw_params);
err = snd_pcm_hw_params_any(pcm, hw_params);
if(err<0){fprintf(stderr, "snd_pcm_hw_params_any failed: %s\n", snd_strerror(err));return err;}
#if ENABLE_SETPARAMS & 1
err = snd_pcm_hw_params_set_rate_min(pcm, hw_params, &rate, 0);
if(err<0){fprintf(stderr, "snd_pcm_hw_params_set_rate_min failed: %s\n", snd_strerror(err));return err;}
#endif
#if ENABLE_SETPARAMS & 2
err = snd_pcm_hw_params_set_period_size_near(pcm, hw_params, &uframes, 0);
if(err<0){fprintf(stderr, "snd_pcm_hw_params_set_period_size failed: %s\n", snd_strerror(err));return err;}
#endif
err = snd_pcm_hw_params(pcm, hw_params);
if(err<0){fprintf(stderr, "snd_pcm_hw_params failed: %s\n", snd_strerror(err));return err;}
printf("configuring device succeeded\n");
return 0;
}
void pcm_open(char*name) {
int err=0;
snd_pcm_t *pcmIn=0, *pcmOut=0;
printf("trying to open '%s' as CAPTURE\n", name);
err = snd_pcm_open(&pcmIn, name, SND_PCM_STREAM_CAPTURE, SND_PCM_NONBLOCK);
if(err<0){fprintf(stderr, "snd_pcm_open(CAPTURE) failed: %s\n", snd_strerror(err));goto closeit;}
err=snd_pcm_nonblock(pcmIn, 1);
if(err<0){fprintf(stderr, "snd_pcm_nonblock failed: %s\n", snd_strerror(err));goto closeit;}
pcm_configure(pcmIn);
fprintf(stderr, "CAPTURE configured\n");
printf("trying to open '%s' as PLAYBACK\n", name);
err = snd_pcm_open(&pcmOut, name, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
if(err<0){fprintf(stderr, "snd_pcm_open(PLAYBACK) failed: %s\n", snd_strerror(err));goto closeit;}
err=snd_pcm_nonblock(pcmOut, 1);
if(err<0){fprintf(stderr, "snd_pcm_nonblock failed: %s\n", snd_strerror(err));goto closeit;}
pcm_configure(pcmOut);
fprintf(stderr, "PLAYBACK configured\n");
closeit:
if(pcmIn)snd_pcm_close(pcmIn);
if(pcmOut)snd_pcm_close(pcmOut);
}
int main(int argc, char**argv) {
int i=0;
if(argc>1) {
for(i=1; i<argc; i++) {
pcm_open(argv[i]);
}
} else {
pcm_open("hw:0");
pcm_open("plughw:0");
}
fprintf(stderr, "bye bye\n");
return 0;
}
Attachment:
smime.p7s
Description: S/MIME Cryptographic Signature
_______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
