check if mic is muted and unmute it before capturing audio.

I lost 7 days worth of captures due to misclicking the microphone mute
button. Ended up with a week's worth of silent audio

main.odin

@@ -23,7 +23,60 @@ WAV_HEADER_SIZE :: 44
 
 interrupted := false
 
+unmute_if_we_are_mute :: proc() {
+    handle: ^alsa.mixer_t
+    sid: ^alsa.mixer_selem_id_t
+    selem_name :: "Capture"
+
+    alsa.mixer_selem_id_malloc(&sid)
+    defer alsa.mixer_selem_id_free(sid)
+    alsa.mixer_selem_id_set_index(sid, 0)
+    alsa.mixer_selem_id_set_name(sid, selem_name)
+
+    if alsa.mixer_open(&handle, 0) < 0 {
+        panic("Failed to open mixer")
+    }
+    defer alsa.mixer_close(handle)
+
+    if alsa.mixer_attach(handle, DEVICE) < 0 {
+        panic("Failed to attach mixer to device")
+    }
+
+    if alsa.mixer_selem_register(handle, nil, nil) < 0 {
+        panic("Failed to register mixer element")
+    }
+
+    if alsa.mixer_load(handle) < 0 {
+        panic("Failed to load mixer")
+    }
+
+    // We can loop over the available elements and print their names. "Capture" seems to work tho
+    // fmt.println(alsa.mixer_first_elem(handle))
+    // for elem := alsa.mixer_first_elem(handle); elem != nil; elem = alsa.mixer_elem_next(elem) {
+    //     name := alsa.mixer_selem_get_name(elem)
+    //     fmt.println(name)
+    // }
+
+    elem := alsa.mixer_find_selem(handle, sid)
+    assert(elem != nil, "Mixer element is nil")
+
+    mic_enabled: i32
+
+    if alsa.mixer_selem_has_capture_switch(elem) {
+        assert(alsa.mixer_selem_get_capture_switch(elem, .MONO, &mic_enabled) >= 0, "get_capture_switch for mono channel failed")
+    } else {
+        panic("No capture switch found")
+    }
+
+    if mic_enabled == 0 {
+        fmt.println("I Have no Ears, and I Must Listen (Attempting to unmute microphone)")
+        assert(alsa.mixer_selem_set_capture_switch(elem, .MONO, 1) >= 0, "Failed to unmute capture device")
+    }
+}
+
 main :: proc() {
+    unmute_if_we_are_mute()
+
     handle: ^alsa.pcm_t
 
     alsa_err := alsa.pcm_open(&handle, DEVICE, .CAPTURE, .BLOCK)