avfilter/af_stereowiden: add support for commands

doc/filters.texi

@@ -5171,6 +5171,10 @@ channels. Default is 0.3.
 Set level of input signal of original channel. Default is 0.8.
 @end table
 
+@subsection Commands
+
+This filter supports the all above options except @code{delay} as @ref{commands}.
+
 @section superequalizer
 Apply 18 band equalizer.
 

libavfilter/af_stereowiden.c

@@ -39,13 +39,14 @@ typedef struct StereoWidenContext {
 } StereoWidenContext;
 
 #define OFFSET(x) offsetof(StereoWidenContext, x)
-#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+#define A  AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+#define AT AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
 
 static const AVOption stereowiden_options[] = {
     { "delay",     "set delay time",    OFFSET(delay),     AV_OPT_TYPE_FLOAT, {.dbl=20}, 1, 100, A },
-    { "feedback",  "set feedback gain", OFFSET(feedback),  AV_OPT_TYPE_FLOAT, {.dbl=.3}, 0, 0.9, A },
-    { "crossfeed", "set cross feed",    OFFSET(crossfeed), AV_OPT_TYPE_FLOAT, {.dbl=.3}, 0, 0.8, A },
-    { "drymix",    "set dry-mix",       OFFSET(drymix),    AV_OPT_TYPE_FLOAT, {.dbl=.8}, 0, 1.0, A },
+    { "feedback",  "set feedback gain", OFFSET(feedback),  AV_OPT_TYPE_FLOAT, {.dbl=.3}, 0, 0.9, AT },
+    { "crossfeed", "set cross feed",    OFFSET(crossfeed), AV_OPT_TYPE_FLOAT, {.dbl=.3}, 0, 0.8, AT },
+    { "drymix",    "set dry-mix",       OFFSET(drymix),    AV_OPT_TYPE_FLOAT, {.dbl=.8}, 0, 1.0, AT },
     { NULL }
 };
 
@@ -165,4 +166,5 @@ AVFilter ff_af_stereowiden = {
     .inputs         = inputs,
     .outputs        = outputs,
     .flags          = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
+    .process_command = ff_filter_process_command,
 };