I see lots of code like this online : http://hdlab.googlecode.com/svn/trunk/xbmc/tools/XBMCLive/setAlsaVolumes.c Unfortunately on the raspberry Pi board the min value from snd_mixer_selem_get_playback_volume_range() is -10239. If I do a calculation volume*max/100 then the lowest value I can get is zero. As a result the code only moves the volume by the top 20% ish of its range. Is the min value supposed to be negative or is the most common code everyone is using broken ? Thanks, Jon Example output min=-10239 max=400 writing 0 **** Code i've crudely hacked together from various examples. // volume is percentage #include <alsa/asoundlib.h> void set_volume(long volume) { long min, max, newvol; snd_mixer_t *handle = NULL; snd_mixer_selem_id_t *sid = NULL; const char *card = "default"; //const char *selem_name = "Master"; const char *selem_name = "PCM"; if (snd_mixer_open(&handle, 0) < 0) { printf("%s: set_volume() RPI - snd_mixer_open failed\n",PROGNAME); fflush(stdout); perror("snd_mixer_open"); } else { snd_mixer_attach(handle, card); snd_mixer_selem_register(handle, NULL, NULL); snd_mixer_load(handle); //snd_mixer_selem_id_alloca(&sid); snd_mixer_selem_id_malloc(&sid); snd_mixer_selem_id_set_index(sid, 0); snd_mixer_selem_id_set_name(sid, selem_name); snd_mixer_elem_t* elem = snd_mixer_find_selem(handle, sid); if (elem == NULL) { printf("%s: set_volume() RPI - snd_mixer_find_selem failed()\n",PROGNAME); fflush(stdout); } else { snd_mixer_selem_get_playback_volume_range(elem, &min, &max); newvol= ( (long)volume * (long)max ) / (long)100 ; printf("min=%ld max=%ld writing %ld\n",min,max,newvol); fflush(stdout); if ( snd_mixer_selem_set_playback_volume_all(elem,newvol) <0) { printf("%s: set_volume() RPI - snd_mixer_selem_set_playback_volume_all() failed\n",PROGNAME); fflush(stdout); } } snd_mixer_close(handle); } } ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
