avfilter/avfilter: add ff_filter_process_command()

libavfilter/avfilter.c

@@ -884,6 +884,19 @@ static int process_options(AVFilterContext *ctx, AVDictionary **options,
     return count;
 }
 
+int ff_filter_process_command(AVFilterContext *ctx, const char *cmd,
+                              const char *arg, char *res, int res_len, int flags)
+{
+    const AVOption *o;
+
+    if (!ctx->filter->priv_class)
+        return 0;
+    o = av_opt_find2(ctx->priv, cmd, NULL, AV_OPT_FLAG_RUNTIME_PARAM | AV_OPT_FLAG_FILTERING_PARAM, AV_OPT_SEARCH_CHILDREN, NULL);
+    if (!o)
+        return AVERROR(ENOSYS);
+    return av_opt_set(ctx->priv, cmd, arg, 0);
+}
+
 int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options)
 {
     int ret = 0;

libavfilter/internal.h

@@ -411,6 +411,13 @@ static inline int ff_norm_qscale(int qscale, int type)
  */
 int ff_filter_get_nb_threads(AVFilterContext *ctx);
 
+/**
+ * Generic processing of user supplied commands that are set
+ * in the same way as the filter options.
+ */
+int ff_filter_process_command(AVFilterContext *ctx, const char *cmd,
+                              const char *arg, char *res, int res_len, int flags);
+
 /**
  * Perform any additional setup required for hardware frames.
  *