diff options
Diffstat (limited to 'alsa.c')
| -rw-r--r-- | alsa.c | 201 |
1 files changed, 201 insertions, 0 deletions
@@ -0,0 +1,201 @@ +/* + * sndctl - a plugin for the Video Disk Recorder + * file: alsa.c + * description: handling of the Alsa API + * + * author: Thomas Hildebrandt <toxym@web.de> + * + * inspired by and reengineered from 'avolctl' + * thanks to Martin Prochnow <nordlichtl@martins-kabuff.de> + */ + +#include "defaults.h" +#include "alsa.h" + +/********************************************************* + * member functions for class cAlsa + *********************************************************/ + +/* + * constructors + */ +cAlsa::cAlsa(){ + init(); +} + +/* + * destructor + */ +cAlsa::~cAlsa(){ +} + +/* + * Initialize mapCardNameToHwNumber and mapCardNumberToMixerHandle + */ +static void dumpErrorMessage(string msg, int err) +{ + msg.append(snd_strerror(err)); + dsyslog(msg.c_str()); +} + +void cAlsa::init( void ) { + char hwName[64]; + snd_ctl_card_info_t *info; + snd_ctl_card_info_malloc(&info); + snd_ctl_t *ctl; + snd_hctl_t *hctl; + int err; + + int number = -1; + for (;;) { + /* open card for getting the mixers of this card */ + err = snd_card_next(&number); + if (err < 0) { + dumpErrorMessage(string("sndctl (cAlsa::init): ERROR: Cannot get next card number because "), err); + break; + } + if (number < 0) + break; + sprintf(hwName, "hw:%d", number); + if ((err = snd_ctl_open(&ctl, hwName, 0)) < 0) { + dumpErrorMessage(string("sndctl (cAlsa::init): ERROR: Cannot open card number because "), err); + break; + } + if ((err = snd_ctl_card_info(ctl, info)) < 0) { + dumpErrorMessage(string("sndctl (cAlsa::init): ERROR: Cannot get sound card info because "), err); + break; + } + dsyslog("sndctl (cAlsa::init): Found sound card:%s\n", snd_ctl_card_info_get_name(info)); + + if ((err = snd_hctl_open(&hctl, hwName, 0)) < 0) { + dumpErrorMessage(string("sndctl (cAlsa::init): ERROR: Cannot snd_hctl_open because "), err); + break; + } + + /* now iterate over the mixers */ + if ((err = snd_hctl_load(hctl)) < 0) { + dumpErrorMessage(string("sndctl (cAlsa::init): ERROR: Cannot snd_hctl_load because "), err); + } + + snd_hctl_elem_t *elem = NULL; + snd_ctl_elem_info_t *elemInfo; + snd_ctl_elem_info_alloca(&elemInfo); + + int controlNr = 0; + for (elem = snd_hctl_first_elem(hctl); elem; elem = snd_hctl_elem_next(elem)) { + if ((err = snd_hctl_elem_info(elem, elemInfo)) < 0) { + dumpErrorMessage(string("sndctl (cAlsa::init): ERROR: Cannot snd_hctl_elem_info because "), err); + break; + } + if (snd_ctl_elem_info_is_inactive(elemInfo)) { + continue; + } + + snd_ctl_elem_id_t *id; + snd_ctl_elem_id_alloca(&id); + snd_hctl_elem_get_id(elem, id); + + if (snd_ctl_elem_info_get_type(elemInfo) == SND_CTL_ELEM_TYPE_INTEGER) { + alsacontrol *control = new alsacontrol(); + control->min = snd_ctl_elem_info_get_min(elemInfo); + control->max = snd_ctl_elem_info_get_max(elemInfo); + control->soundCardId = string(snd_ctl_card_info_get_name(info)); + control->hwName = string(hwName); + + // check for a senseful range + if( control->min == 0 && control->max > control->min && control->max > 10 ){ + // get name + control->name = string( snd_ctl_elem_id_get_name(id)); + control->mixername = string( snd_ctl_elem_id_get_name(id)); + control->controlNr = controlNr; + controlNr++; + + dsyslog( "sndctl (cAlsa::init): '%s' updated with min=%ld and max=%ld", control->name.c_str(), control->min, control->max ); + vControls.push_back(control); + } else { + delete control; + } + } else { + dsyslog("sndctl (cAlsa::init): '%s' has no playback volume", snd_ctl_elem_id_get_name(id)); + } + } + snd_hctl_close(hctl); + snd_ctl_close(ctl); + } + snd_ctl_card_info_free(info); + dsyslog("sndctl (cAlsa::init): found %d controls:", vControls.size()); +} + +/* + * checks for a mixer with a given name + */ +bool cAlsa::IsMixer( string Name ){ + snd_mixer_elem_t *elem; + + // search in all mixers for 'Name' + for( elem = snd_mixer_first_elem(handle); elem; elem = snd_mixer_elem_next( elem )){ + if(( strcmp(snd_mixer_selem_get_name( elem ), Name.c_str()) == 0 ) && + snd_mixer_selem_is_active( elem ) && + ( snd_mixer_selem_has_playback_volume( elem ) || + snd_mixer_selem_has_playback_switch( elem ))) + return true; + } + + // nothing found + return false; +} + +/* + * set the volume of all controls + */ +void cAlsa::Volumes( void ){ +/* snd_mixer_elem_t *elem; + int i; + snd_mixer_selem_id_t *sid; + snd_mixer_selem_id_malloc( &sid ); +*/ + + // loop over all controls + for(int i = 0; i < vControls.size(); i++ ){ + alsacontrol *control = static_cast<alsacontrol*>(vControls[i]); + if( control->volume >= 0 ){ + int err; + // get ID from the name + dsyslog("sndctl (cAlsa::Volumes): trying to set control '%s' of card '%s'", control->name.c_str(), control->hwName.c_str()); + snd_hctl_t *hctl; + if ((err = snd_hctl_open(&hctl, control->hwName.c_str(), 0)) < 0) { + dumpErrorMessage(string("sndctl (cAlsa::Volumes): snd_hctl_open failed because "), err); + break; + } + if ((err = snd_hctl_load(hctl)) < 0) { + dumpErrorMessage(string("sndctl (cAlsa::Volumes): snd_hctl_load failed because "), err); + break; + } + + snd_ctl_elem_id_t *id; + snd_ctl_elem_id_alloca(&id); + snd_ctl_elem_id_set_interface(id, SND_CTL_ELEM_IFACE_MIXER); + + snd_ctl_elem_id_set_name(id, control->mixername.c_str()); + + snd_hctl_elem_t *elem = snd_hctl_find_elem(hctl, id); + + snd_ctl_elem_value_t *ctl; + snd_ctl_elem_value_alloca(&ctl); + snd_ctl_elem_value_set_id(ctl, id); + + /* left */ + snd_ctl_elem_value_set_integer(ctl, 0, control->volume); + /* right */ + snd_ctl_elem_value_set_integer(ctl, 1, control->volume); + + if ((err = snd_hctl_elem_write(elem, ctl)) < 0) { + dumpErrorMessage(string("sndctl (cAlsa::Volumes): snd_hctl_elem_write failed because "), err); + break; + } + + snd_hctl_close(hctl); + + } + } +} |