af/vf-command: add ability to target a specific lavfi filter

fixes: #11180

4 files changed, 33 insertions, 15 deletions

diff --git a/DOCS/man/input.rst b/DOCS/man/input.rst
index 024e8d1a5c..59ca00c968 100644
--- a/DOCS/man/input.rst
+++ b/DOCS/man/input.rst
@@ -1296,16 +1296,21 @@ Input Commands that are Possibly Subject to Change
     The ``flags`` argument is like the first argument to ``screenshot`` and
     supports ``subtitles``, ``video``, ``window``.
 
-``vf-command <label> <command> <argument>``
-    Send a command to the filter with the given ``<label>``. Use ``all`` to send
-    it to all filters at once. The command and argument string is filter
-    specific. Currently, this only works with the ``lavfi`` filter - see
-    the libavfilter documentation for which commands a filter supports.
+``vf-command <label> <command> <argument> [<target>]``
+    Send a command to the filter. Note that currently, this only works with
+    the ``lavfi`` filter. Refer to the libavfilter documentation for the list
+    of supported commands for each filter.
 
-    Note that the ``<label>`` is a mpv filter label, not a libavfilter filter
-    name.
+    ``<label>`` is a mpv filter label, use ``all`` to send it to all filters
+    at once.
 
-``af-command <label> <command> <argument>``
+    ``<command>`` and ``<argument>`` are filter-specific strings.
+
+    ``<target>`` is a filter or filter instance name and defaults to ``all``.
+    Note that the target is an additional specifier for filters that
+    support them, such as complex ``lavfi`` filter chains.
+
+``af-command <label> <command> <argument> [<target>]``
     Same as ``vf-command``, but for audio filters.
 
 ``apply-profile <name> [<mode>]``
diff --git a/filters/f_lavfi.c b/filters/f_lavfi.c
index ec50dd5946..fe7d3e4527 100644
--- a/filters/f_lavfi.c
+++ b/filters/f_lavfi.c
@@ -814,7 +814,8 @@ static bool lavfi_command(struct mp_filter *f, struct mp_filter_command *cmd)
 
     switch (cmd->type) {
     case MP_FILTER_COMMAND_TEXT: {
-        return avfilter_graph_send_command(c->graph, "all", cmd->cmd, cmd->arg,
+        return avfilter_graph_send_command(c->graph, cmd->target,
+                                           cmd->cmd, cmd->arg,
                                            &(char){0}, 0, 0) >= 0;
     }
     case MP_FILTER_COMMAND_GET_META: {
diff --git a/filters/filter.h b/filters/filter.h
index 8820199a42..44d5f59707 100644
--- a/filters/filter.h
+++ b/filters/filter.h
@@ -376,6 +376,7 @@ struct mp_filter_command {
     enum mp_filter_command_type type;
 
     // For MP_FILTER_COMMAND_TEXT
+    const char *target;
     const char *cmd;
     const char *arg;
 
diff --git a/player/command.c b/player/command.c
index 8470e802ea..ef4dbd42c0 100644
--- a/player/command.c
+++ b/player/command.c
@@ -5999,6 +5999,7 @@ static void cmd_filter_command(void *p)
     }
     struct mp_filter_command filter_cmd = {
         .type = MP_FILTER_COMMAND_TEXT,
+        .target = cmd->args[3].v.s,
         .cmd = cmd->args[1].v.s,
         .arg = cmd->args[2].v.s,
     };
@@ -6643,13 +6644,23 @@ const struct mp_cmd_def mp_cmds[] = {
                           {"value", OPT_STRING(v.s)}, },
         .priv = &(const int){STREAM_VIDEO} },
 
-    { "af-command", cmd_filter_command, { {"label", OPT_STRING(v.s)},
-                                          {"command", OPT_STRING(v.s)},
-                                          {"argument", OPT_STRING(v.s)}, },
+    { "af-command", cmd_filter_command,
+        {
+            {"label", OPT_STRING(v.s)},
+            {"command", OPT_STRING(v.s)},
+            {"argument", OPT_STRING(v.s)},
+            {"target", OPT_STRING(v.s), OPTDEF_STR("all"),
+                .flags = MP_CMD_OPT_ARG},
+        },
         .priv = &(const int){STREAM_AUDIO} },
-    { "vf-command", cmd_filter_command, { {"label", OPT_STRING(v.s)},
-                                          {"command", OPT_STRING(v.s)},
-                                          {"argument", OPT_STRING(v.s)}, },
+    { "vf-command", cmd_filter_command,
+        {
+            {"label", OPT_STRING(v.s)},
+            {"command", OPT_STRING(v.s)},
+            {"argument", OPT_STRING(v.s)},
+            {"target", OPT_STRING(v.s), OPTDEF_STR("all"),
+                .flags = MP_CMD_OPT_ARG},
+        },
         .priv = &(const int){STREAM_VIDEO} },
 
     { "ao-reload", cmd_ao_reload },