void audio_set_default_levels() { int err; snd_ctl_t *ctl; snd_ctl_elem_value_t *val; snd_ctl_elem_value_alloca(&val); if (snd_ctl_open(&ctl, ALSA_DEVICE, 0)) { fprintf(stderr, "can't open audio device"); return; } /* unmute microphone */ snd_ctl_elem_value_set_interface(val, SND_CTL_ELEM_IFACE_MIXER); snd_ctl_elem_value_set_name(val, "Mic Capture Switch"); snd_ctl_elem_value_set_integer(val, 0, 1); err = snd_ctl_elem_write(ctl, val); if (err) fprintf(stderr, "can't unmute microphone: %s\n", snd_strerror(err)); /* unmute speaker */ snd_ctl_elem_value_clear(val); snd_ctl_elem_value_set_interface(val, SND_CTL_ELEM_IFACE_MIXER); snd_ctl_elem_value_set_name(val, "Speaker Playback Switch"); snd_ctl_elem_value_set_integer(val, 0, 1); err = snd_ctl_elem_write(ctl, val); if (err) fprintf(stderr, "can't unmute speaker: %s\n", snd_strerror(err)); /* set mic volume */ snd_ctl_elem_value_clear(val); snd_ctl_elem_value_set_interface(val, SND_CTL_ELEM_IFACE_MIXER); snd_ctl_elem_value_set_name(val, "Mic Capture Volume"); snd_ctl_elem_value_set_integer(val, 0, DEFAULT_MIC_VOL); err = snd_ctl_elem_write(ctl, val); if (err) fprintf(stderr, "can't set microphone volume: %s\n", snd_strerror(err)); /* set speaker volume */ snd_ctl_elem_value_clear(val); snd_ctl_elem_value_set_interface(val, SND_CTL_ELEM_IFACE_MIXER); snd_ctl_elem_value_set_name(val, "Speaker Playback Volume"); snd_ctl_elem_value_set_integer(val, 0, DEFAULT_SPKR_VOL); snd_ctl_elem_value_set_integer(val, 1, DEFAULT_SPKR_VOL); err = snd_ctl_elem_write(ctl, val); if (err) fprintf(stderr, "can't set speaker volume: %s\n", snd_strerror(err)); /* set capture source */ snd_ctl_elem_value_clear(val); snd_ctl_elem_value_set_interface(val, SND_CTL_ELEM_IFACE_MIXER); snd_ctl_elem_value_set_name(val, "PCM Capture Source"); snd_ctl_elem_value_set_integer(val, 0, 0); err = snd_ctl_elem_write(ctl, val); if (err) fprintf(stderr, "can't set capture source: %s\n", snd_strerror(err)); snd_ctl_close(ctl); }
/************************************************************************** * ALSA_CheckSetVolume [internal] * * Helper function for Alsa volume queries. This tries to simplify * the process of managing the volume. All parameters are optional * (pass NULL to ignore or not use). * Return values are MMSYSERR_NOERROR on success, or !0 on failure; * error codes are normalized into the possible documented return * values from waveOutGetVolume. */ int ALSA_CheckSetVolume(snd_hctl_t *hctl, int *out_left, int *out_right, int *out_min, int *out_max, int *out_step, int *new_left, int *new_right) { int rc = MMSYSERR_NOERROR; int value_count = 0; snd_hctl_elem_t * elem = NULL; snd_ctl_elem_info_t * eleminfop = NULL; snd_ctl_elem_value_t * elemvaluep = NULL; snd_ctl_elem_id_t * elemidp = NULL; const char *names[] = {"PCM Playback Volume", "Line Playback Volume", NULL}; const char **name; #define EXIT_ON_ERROR(f,txt,exitcode) do \ { \ int err; \ if ( (err = (f) ) < 0) \ { \ ERR(txt " failed: %s\n", snd_strerror(err)); \ rc = exitcode; \ goto out; \ } \ } while(0) if (! hctl) return MMSYSERR_NOTSUPPORTED; /* Allocate areas to return information about the volume */ EXIT_ON_ERROR(snd_ctl_elem_id_malloc(&elemidp), "snd_ctl_elem_id_malloc", MMSYSERR_NOMEM); EXIT_ON_ERROR(snd_ctl_elem_value_malloc (&elemvaluep), "snd_ctl_elem_value_malloc", MMSYSERR_NOMEM); EXIT_ON_ERROR(snd_ctl_elem_info_malloc (&eleminfop), "snd_ctl_elem_info_malloc", MMSYSERR_NOMEM); snd_ctl_elem_id_clear(elemidp); snd_ctl_elem_value_clear(elemvaluep); snd_ctl_elem_info_clear(eleminfop); /* Setup and find an element id that exactly matches the characteristic we want ** FIXME: It is probably short sighted to hard code and fixate on PCM Playback Volume */ for( name = names; *name; name++ ) { snd_ctl_elem_id_set_name(elemidp, *name); snd_ctl_elem_id_set_interface(elemidp, SND_CTL_ELEM_IFACE_MIXER); elem = snd_hctl_find_elem(hctl, elemidp); if (elem) { /* Read and return volume information */ EXIT_ON_ERROR(snd_hctl_elem_info(elem, eleminfop), "snd_hctl_elem_info", MMSYSERR_NOTSUPPORTED); value_count = snd_ctl_elem_info_get_count(eleminfop); if (out_min || out_max || out_step) { if (!snd_ctl_elem_info_is_readable(eleminfop)) { ERR("snd_ctl_elem_info_is_readable returned false; cannot return info\n"); rc = MMSYSERR_NOTSUPPORTED; goto out; } if (out_min) *out_min = snd_ctl_elem_info_get_min(eleminfop); if (out_max) *out_max = snd_ctl_elem_info_get_max(eleminfop); if (out_step) *out_step = snd_ctl_elem_info_get_step(eleminfop); } if (out_left || out_right) { EXIT_ON_ERROR(snd_hctl_elem_read(elem, elemvaluep), "snd_hctl_elem_read", MMSYSERR_NOTSUPPORTED); if (out_left) *out_left = snd_ctl_elem_value_get_integer(elemvaluep, 0); if (out_right) { if (value_count == 1) *out_right = snd_ctl_elem_value_get_integer(elemvaluep, 0); else if (value_count == 2) *out_right = snd_ctl_elem_value_get_integer(elemvaluep, 1); else { ERR("Unexpected value count %d from snd_ctl_elem_info_get_count while getting volume info\n", value_count); rc = -1; goto out; } } } /* Set the volume */ if (new_left || new_right) { EXIT_ON_ERROR(snd_hctl_elem_read(elem, elemvaluep), "snd_hctl_elem_read", MMSYSERR_NOTSUPPORTED); if (new_left) snd_ctl_elem_value_set_integer(elemvaluep, 0, *new_left); if (new_right) { if (value_count == 1) snd_ctl_elem_value_set_integer(elemvaluep, 0, *new_right); else if (value_count == 2) snd_ctl_elem_value_set_integer(elemvaluep, 1, *new_right); else { ERR("Unexpected value count %d from snd_ctl_elem_info_get_count while setting volume info\n", value_count); rc = -1; goto out; } } EXIT_ON_ERROR(snd_hctl_elem_write(elem, elemvaluep), "snd_hctl_elem_write", MMSYSERR_NOTSUPPORTED); } break; } } if( !*name ) { ERR("Could not find '{PCM,Line} Playback Volume' element\n"); rc = MMSYSERR_NOTSUPPORTED; } #undef EXIT_ON_ERROR out: if (elemvaluep) snd_ctl_elem_value_free(elemvaluep); if (eleminfop) snd_ctl_elem_info_free(eleminfop); if (elemidp) snd_ctl_elem_id_free(elemidp); return rc; }