LXR toybox/toys/other/mix.c

   1/* mix.c - A very basic mixer.
   2 *
   3 * Copyright 2014 Brad Conroy, dedicated to the Public Domain.
   4 *
   5
   6USE_MIX(NEWTOY(mix, "c:d:l#r#", TOYFLAG_USR|TOYFLAG_BIN))
   7
   8config MIX
   9  bool "mix"
  10  default y
  11  help
  12   usage: mix [-d DEV] [-c CHANNEL] [-l VOL] [-r RIGHT]
  13
  14   List OSS sound channels (module snd-mixer-oss), or set volume(s).
  15
  16   -c CHANNEL   Set/show volume of CHANNEL (default first channel found)
  17   -d DEV               Device node (default /dev/mixer)
  18   -l VOL               Volume level
  19   -r RIGHT     Volume of right stereo channel (with -r, -l sets left volume)
  20*/
  21
  22#define FOR_mix
  23#include "toys.h"
  24#include <linux/soundcard.h>
  25
  26GLOBALS(
  27   long r, l;
  28   char *d, *c;
  29)
  30
  31void mix_main(void)
  32{
  33  const char *channels[SOUND_MIXER_NRDEVICES] = SOUND_DEVICE_NAMES;
  34  int mask, channel = -1, level, fd;
  35
  36  if (!TT.d) TT.d = "/dev/mixer";
  37  fd = xopen(TT.d, O_RDWR|O_NONBLOCK);
  38  xioctl(fd, SOUND_MIXER_READ_DEVMASK, &mask);
  39
  40  for (channel = 0; channel < SOUND_MIXER_NRDEVICES; channel++) {
  41    if ((1<<channel) & mask) {
  42      if (TT.c) {
  43        if (!strcmp(channels[channel], TT.c)) break;
  44      } else if (toys.optflags & FLAG_l) break;
  45      else printf("%s\n", channels[channel]);
  46    }
  47  }
  48
  49  if (!(toys.optflags & (FLAG_c|FLAG_l))) return;
  50  else if (channel == SOUND_MIXER_NRDEVICES) error_exit("bad -c '%s'", TT.c);
  51
  52  if (!(toys.optflags & FLAG_l)) {
  53    xioctl(fd, MIXER_READ(channel), &level);
  54    if (level > 0xFF)
  55      xprintf("%s:%s = left:%d\t right:%d\n",
  56              TT.d, channels[channel], level>>8, level & 0xFF);
  57    else xprintf("%s:%s = %d\n", TT.d, channels[channel], level);
  58  } else {
  59    level = TT.l;
  60    if (!(toys.optflags & FLAG_r)) level = TT.r | (level<<8);
  61
  62    xioctl(fd, MIXER_WRITE(channel), &level);
  63  }
  64
  65  if (CFG_TOYBOX_FREE) close(fd);
  66}
  67