options: deprecate --ff- options and properties

Some old crap which nobody needs and which probably nobody uses.

This relies on a GCC extension: using "## __VA_ARGS__" to remove the
comma from the argument list if the va args are empty. It's supported
by clang, and there's some chance newer standards will introduce a
proper way to do this. (Even if it breaks somewhere, it will be a
problem only for 1 release, since I want to drop the deprecated
properties immediately.)

DOCS/interface-changes.rst

@@ -61,6 +61,9 @@ Interface changes
       introspection of the option/property), also affects some properties
     - rename --hwdec=rpi to --hwdec=mmal, sane for the -copy variant (no
       backwards compatibility)
+    - deprecate the --ff-aid, --ff-vid, -ff-sid options and properties (there is
+      no replacement, but you can manually query the track property and use the
+      "ff-index" field to find the mpv track ID to imitate this behavior)
  --- mpv 0.27.0 ---
     - drop previously deprecated --field-dominance option
     - drop previously deprecated "osd" command

DOCS/man/options.rst

@@ -73,6 +73,8 @@ Track Selection
     options), there will be streams with duplicate IDs. In this case, the
     first stream in order is selected.
 
+    Deprecated.
+
 ``--edition=<ID|auto>``
     (Matroska files only)
     Specify the edition (set of chapters) to use, where 0 is the first. If set

options/m_option.h

@@ -670,8 +670,9 @@ extern const char m_option_path_separator;
 #define OPT_SIZE_BOX(...) \
     OPT_GENERAL(struct m_geometry, __VA_ARGS__, .type = &m_option_type_size_box)
 
-#define OPT_TRACKCHOICE(name, var) \
-    OPT_CHOICE_OR_INT(name, var, 0, 0, 8190, ({"no", -2}, {"auto", -1}))
+#define OPT_TRACKCHOICE(name, var, ...) \
+    OPT_CHOICE_OR_INT(name, var, 0, 0, 8190, ({"no", -2}, {"auto", -1}), \
+    ## __VA_ARGS__)
 
 #define OPT_ASPECT(...) \
     OPT_GENERAL(float, __VA_ARGS__, .type = &m_option_type_aspect)

options/options.c

@@ -323,9 +323,12 @@ const m_option_t mp_opts[] = {
     OPT_TRACKCHOICE("vid", stream_id[0][STREAM_VIDEO]),
     OPT_TRACKCHOICE("sid", stream_id[0][STREAM_SUB]),
     OPT_TRACKCHOICE("secondary-sid", stream_id[1][STREAM_SUB]),
-    OPT_TRACKCHOICE("ff-aid", stream_id_ff[STREAM_AUDIO]),
-    OPT_TRACKCHOICE("ff-vid", stream_id_ff[STREAM_VIDEO]),
-    OPT_TRACKCHOICE("ff-sid", stream_id_ff[STREAM_SUB]),
+    OPT_TRACKCHOICE("ff-aid", stream_id_ff[STREAM_AUDIO],
+                    .deprecation_message = "no replacement"),
+    OPT_TRACKCHOICE("ff-vid", stream_id_ff[STREAM_VIDEO],
+                    .deprecation_message = "no replacement"),
+    OPT_TRACKCHOICE("ff-sid", stream_id_ff[STREAM_SUB],
+                    .deprecation_message = "no replacement"),
     OPT_ALIAS("sub", "sid"),
     OPT_ALIAS("video", "vid"),
     OPT_ALIAS("audio", "aid"),

player/command.c

@@ -2193,6 +2193,8 @@ static int property_switch_track_ff(void *ctx, struct m_property *prop,
         *(int *) arg = track ? track->ff_index : -2;
         return M_PROPERTY_OK;
     case M_PROPERTY_SET: {
+        MP_WARN(mpctx, "Warning: property '%s' is deprecated and "
+                "will be removed in the future.\n", prop->name);
         int id = *(int *)arg;
         if (mpctx->playback_initialized) {
             track = NULL;