options: remove deprecated auto choice for --mute

Since 995c47da9a, setting --mute=auto has
been equivalent to --mute=no. It was formally documented later in
79e20ff485. This is an old legacy relic
and the auto choice popping up during auto completion could be confusing
to users who aren't aware of the history. Remove it for good and convert
the option to a proper boolean.

DOCS/man/options.rst

@@ -2052,11 +2052,9 @@ Audio
     Audio delay in seconds (positive or negative float value). Positive values
     delay the audio, and negative values delay the video.
 
-``--mute=<yes|no|auto>``
+``--mute=<yes|no>``
     Set startup audio mute status (default: no).
 
-    ``auto`` is a deprecated possible value that is equivalent to ``no``.
-
     See also: ``--volume``.
 
 ``--audio-demuxer=<[+]name>``

options/options.c

@@ -737,11 +737,7 @@ static const m_option_t mp_opts[] = {
     {"volume-gain-min", OPT_FLOAT(softvol_gain_min), M_RANGE(-150, 0)},
     {"volume-gain", OPT_FLOAT(softvol_gain), .flags = UPDATE_VOL,
         M_RANGE(-150, 150)},
-    {"mute", OPT_CHOICE(softvol_mute,
-        {"no", 0},
-        {"auto", 0},
-        {"yes", 1}),
-        .flags = UPDATE_VOL},
+    {"mute", OPT_BOOL(softvol_mute), .flags = UPDATE_VOL},
     {"replaygain", OPT_CHOICE(rgain_mode,
         {"no", 0},
         {"track", 1},

options/options.h

@@ -189,7 +189,7 @@ typedef struct MPOpts {
     float rgain_preamp;         // Set replaygain pre-amplification
     bool rgain_clip;             // Enable/disable clipping prevention
     float rgain_fallback;
-    int softvol_mute;
+    bool softvol_mute;
     float softvol_max;
     float softvol_gain;
     float softvol_gain_min;

player/audio.c

@@ -176,7 +176,7 @@ void audio_update_volume(struct MPContext *mpctx)
     gain = pow(gain, 3);
     gain *= compute_replaygain(mpctx);
     gain *= db_gain(opts->softvol_gain);
-    if (opts->softvol_mute == 1)
+    if (opts->softvol_mute)
         gain = 0.0;
 
     ao_set_gain(ao_c->ao, gain);