avfilter/af_anlms: add support for commands

doc/filters.texi

@@ -1870,12 +1870,16 @@ Default value is @var{o}.
 @itemize
 @item
 One of many usages of this filter is noise reduction, input audio is filtered
-with same samples that are delayed by fixed ammount, one such example for stereo audio is:
+with same samples that are delayed by fixed amount, one such example for stereo audio is:
 @example
 asplit[a][b],[a]adelay=32S|32S[a],[b][a]anlms=order=128:leakage=0.0005:mu=.5:out_mode=o
 @end example
 @end itemize
 
+@subsection Commands
+
+This filter supports the same commands as options, excluding option @code{order}.
+
 @section anull
 
 Pass the audio source unchanged to the output.

libavfilter/af_anlms.c

@@ -281,6 +281,22 @@ static av_cold int init(AVFilterContext *ctx)
     return 0;
 }
 
+static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
+                           char *res, int res_len, int flags)
+{
+    AudioNLMSContext *s = ctx->priv;
+    int ret;
+
+    if (   !strcmp(cmd, "mu") || !strcmp(cmd, "eps")
+        || !strcmp(cmd, "leakage") || !strcmp(cmd, "out_mode")) {
+        ret = av_opt_set(s, cmd, args, 0);
+    } else {
+        ret = AVERROR(ENOSYS);
+    }
+
+    return ret;
+}
+
 static av_cold void uninit(AVFilterContext *ctx)
 {
     AudioNLMSContext *s = ctx->priv;
@@ -325,4 +341,5 @@ AVFilter ff_af_anlms = {
     .inputs         = inputs,
     .outputs        = outputs,
     .flags          = AVFILTER_FLAG_SLICE_THREADS,
+    .process_command = process_command,
 };