ref: d2089f949edd71626e2391672b723aa2d9fbcb9b
dir: /sys/src/games/music/playlistfs/volume.c/
#include <u.h> #include <libc.h> #include <thread.h> #include <fcall.h> #include "pool.h" #include "playlist.h" int minvolume, maxvolume; void volumeproc(void *) { int fd, n, nf, i, nlines; static char buf[1024]; char *lines[32]; char *fields[8]; char *subfields[9]; int volume[8], nvolumes; threadsetname("volumeproc"); close(srvfd[1]); fd = open("/dev/audioctl", OREAD); if (fd < 0) threadexits(nil); for(;;){ n = read(fd, buf, sizeof buf -1); if (n == 0) continue; if (n < 0){ fprint(2, "volumeproc: read: %r\n"); threadexits("volumeproc"); } buf[n] = '\0'; nlines = getfields(buf, lines, nelem(lines), 1, "\n"); for(i = 0; i < nlines; i++){ nf = tokenize(lines[i], fields, nelem(fields)); if (nf == 0) continue; if (nf != 6 || strcmp(fields[0], "volume") || strcmp(fields[1], "out")) continue; minvolume = strtol(fields[3], nil, 0); maxvolume = strtol(fields[4], nil, 0); if (minvolume >= maxvolume) continue; nvolumes = tokenize(fields[2], subfields, nelem(subfields)); if (nvolumes <= 0 || nvolumes > 8) sysfatal("bad volume data"); if (debug) fprint(2, "volume changed to '"); for (i = 0; i < nvolumes; i++){ volume[i] = strtol(subfields[i], nil, 0); volume[i]= 100*(volume[i]- minvolume)/(maxvolume-minvolume); if (debug) fprint(2, " %d", volume[i]); } if (debug) fprint(2, "'\n"); while (i < 8) volume[i++] = Undef; send(volumechan, volume); } } } void volumeset(int *v) { int fd, i; char buf[256], *p; fd = open("/dev/audioctl", OWRITE); if (fd < 0){ fd = open("/dev/volume", OWRITE); if (fd < 0){ fprint(2, "Can't set volume: %r"); return; } fprint(fd, "audio out %d", v[0]); send(volumechan, v); } else { p = buf; for (i = 0; i < 8; i++){ if (v[i] == Undef) break; p = seprint(p, buf+sizeof buf, (p==buf)?"volume out '%d":" %d", minvolume + v[i] * (maxvolume-minvolume) / 100); } p = seprint(p, buf+sizeof buf, "'\n"); write(fd, buf, p-buf); } close(fd); }