extension of amixer set command:

- add front, rear, center, woofer channel selection
- left and right volumes can be given separately
- volumes can be increased/decreased relatively with + or - suffix

diff --git a/amixer/amixer.1 b/amixer/amixer.1
index 40da79502ae722107f437db009511fa03175ea19..3ebaf1213c452a8c7c289615cfca87216f0b20fa 100644 (file)
--- a/amixer/amixer.1
+++ b/amixer/amixer.1
@@ -33,6 +33,11 @@ Sets the group contents. The parameter can be the volume either as a
 percentage from 0% to 100% or a exact hardware value. The parameters
 \fIcapture, nocapture, mute, unmute\fP are used to toggle capture
 (recording) and muting for the group specified.
+The parameters \fIfront, rear, center, woofer\fP are used to specify
+channels to be changed.
+When plus(+) or minus(-) letter is appended after volume value,
+the volume is incremented or decremented from the current value,
+respectively.
 
 A mixer group must be specified. Only one device can be controlled at
 a time.

diff --git a/amixer/amixer.c b/amixer/amixer.c
index 088d0a3a4ebcc37d9e5af0cade1516a8dab41cde..070c5647fe5223708e08350dd402fa5c3ab2f97f 100644 (file)
--- a/amixer/amixer.c
+++ b/amixer/amixer.c
@@ -264,7 +264,7 @@ static int get_volume(char **ptr, int min, int max, int min_dB, int max_dB)
        return tmp1;
 }
 
-static int get_volume_simple(char **ptr, int min, int max)
+static int get_volume_simple(char **ptr, int min, int max, int orig)
 {
        int tmp, tmp1, tmp2;
 
@@ -289,6 +289,13 @@ static int get_volume_simple(char **ptr, int min, int max)
                tmp1 = convert_prange1(tmp, min, max);
                (*ptr)++;
        }
+       if (**ptr == '+') {
+               tmp1 = orig + tmp1;
+               (*ptr)++;
+       } else if (**ptr == '-') {
+               tmp1 = orig - tmp1;
+               (*ptr)++;
+       }
        tmp1 = check_range(tmp1, min, max);
        if (**ptr == ',')
                (*ptr)++;
@@ -1486,9 +1493,40 @@ int eget(int argc, char *argv[])
        return 0;
 }
 
+typedef struct channel_mask {
+       char *name;
+       unsigned int mask;
+} channel_mask_t;
+static channel_mask_t chanmask[] = {
+       {"frontleft", SND_MIXER_CHN_MASK_FRONT_LEFT},
+       {"frontright", SND_MIXER_CHN_MASK_FRONT_RIGHT},
+       {"frontcenter", SND_MIXER_CHN_MASK_FRONT_CENTER},
+       {"front", SND_MIXER_CHN_MASK_FRONT_LEFT|SND_MIXER_CHN_MASK_FRONT_RIGHT},
+       {"center", SND_MIXER_CHN_MASK_FRONT_CENTER},
+       {"rearleft", SND_MIXER_CHN_MASK_REAR_LEFT},
+       {"rearright", SND_MIXER_CHN_MASK_REAR_RIGHT},
+       {"rear", SND_MIXER_CHN_MASK_REAR_LEFT|SND_MIXER_CHN_MASK_REAR_RIGHT},
+       {"woofer", SND_MIXER_CHN_MASK_WOOFER},
+       {NULL}
+};
+
+static int check_channels(char *arg, unsigned int mask, unsigned int *mask_return)
+{
+       channel_mask_t *c;
+
+       for (c = chanmask; c->name; c++) {
+               if (! strncmp(arg, c->name, strlen(c->name))) {
+                       *mask_return = c->mask & mask;
+                       return 1;
+               }
+       }
+       return 0;
+}
+
 int gset(int argc, char *argv[])
 {
        int err, idx, chn;
+       unsigned int channels;
        snd_mixer_t *handle;
        snd_mixer_gid_t gid;
        snd_mixer_group_t group;
@@ -1516,29 +1554,43 @@ int gset(int argc, char *argv[])
                snd_mixer_close(handle);
                return -1;
        }
+       channels = group.channels; /* all channels */
        for (idx = 1; idx < argc; idx++) {
                if (!strncmp(argv[idx], "mute", 4) ||
                    !strncmp(argv[idx], "off", 3)) {
                        group.mute = group.channels;
+                       continue;
                } else if (!strncmp(argv[idx], "unmute", 6) ||
                           !strncmp(argv[idx], "on", 2)) {
                        group.mute = 0;
+                       continue;
                } else if (!strncmp(argv[idx], "cap", 3) ||
                           !strncmp(argv[idx], "rec", 3)) {
                        group.capture = group.channels;
+                       continue;
                } else if (!strncmp(argv[idx], "nocap", 5) ||
                           !strncmp(argv[idx], "norec", 5)) {
                        group.capture = 0;
-               } else if (isdigit(argv[idx][0])) {
+                       continue;
+               }
+               if (check_channels(argv[idx], group.channels, &channels))
+                       continue;
+               if (isdigit(argv[idx][0]) ||
+                   argv[idx][0] == '+' ||
+                   argv[idx][0] == '-') {
                        char *ptr;
-                       int vol;
+                       int multi;
                
+                       multi = (strchr(argv[idx], ',') != NULL);
                        ptr = argv[idx];
-                       vol = get_volume_simple(&ptr, group.min, group.max);
                        for (chn = 0; chn <= SND_MIXER_CHN_LAST; chn++) {
-                               if (!(group.channels & (1<<chn)))
+                               if (!(group.channels & (1<<chn)) ||
+                                   !(channels & (1<<chn)))
                                        continue;
-                               group.volume.values[chn] = vol;
+
+                               if (! multi)
+                                       ptr = argv[idx];
+                               group.volume.values[chn] = get_volume_simple(&ptr, group.min, group.max, group.volume.values[chn]);
                        }
                } else {
                        error("Unknown setup '%s'..\n", argv[idx]);