[FFmpeg-devel] [PATCH] avfilter: Handle =help to show Filter options documentation

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
---
 libavfilter/avfilter.c |   14 +++++++++++++-
 libavfilter/avfilter.h |    1 +
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
index 8a907dc..df7c84b 100644
--- a/libavfilter/avfilter.c
+++ b/libavfilter/avfilter.c
@@ -236,6 +236,9 @@ int avfilter_config_links(AVFilterContext *filter)
                     return AVERROR(EINVAL);
                 }
             } else if ((ret = config_link(link)) < 0) {
+                if (link->src->help) {
+                    av_opt_show2(&link->src->filter->priv_class, NULL, AV_OPT_FLAG_FILTERING_PARAM, 0);
+                } else
                 av_log(link->src, AV_LOG_ERROR,
                        "Failed to configure output pad on %s\n",
                        link->src->name);
@@ -279,6 +282,9 @@ int avfilter_config_links(AVFilterContext *filter)
 
             if ((config_link = link->dstpad->config_props))
                 if ((ret = config_link(link)) < 0) {
+                    if (link->dst->help) {
+                        av_opt_show2(&link->dst->filter->priv_class, NULL, AV_OPT_FLAG_FILTERING_PARAM, 0);
+                    } else
                     av_log(link->src, AV_LOG_ERROR,
                            "Failed to configure input pad on %s\n",
                            link->dst->name);
@@ -602,6 +608,7 @@ void avfilter_free(AVFilterContext *filter)
 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque)
 {
     int ret=0;
+    filter->help = args && !strncmp(args, "help", 4);
 
     if (filter->filter->shorthand) {
         av_assert0(filter->priv);
@@ -610,14 +617,19 @@ int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque
         av_opt_set_defaults(filter->priv);
         ret = av_opt_set_from_string(filter->priv, args,
                                      filter->filter->shorthand, "=", ":");
-        if (ret < 0)
+        if (ret < 0) {
+            if(filter->help)
+                av_opt_show2(&filter->filter->priv_class, NULL, AV_OPT_FLAG_FILTERING_PARAM, 0);
             return ret;
+        }
         args = NULL;
     }
     if (filter->filter->init_opaque)
         ret = filter->filter->init_opaque(filter, args, opaque);
     else if (filter->filter->init)
         ret = filter->filter->init(filter, args);
+    if(filter->help && ret<0)
+        av_opt_show2(&filter->filter->priv_class, NULL, AV_OPT_FLAG_FILTERING_PARAM, 0);
     return ret;
 }
 
diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
index 455161f..7b5c0f7 100644
--- a/libavfilter/avfilter.h
+++ b/libavfilter/avfilter.h
@@ -522,6 +522,7 @@ struct AVFilterContext {
     void *priv;                     ///< private data for use by the filter
 
     struct AVFilterCommand *command_queue;
+    int help;                       ///< avfilter internal flag indicating that help text possibly was requested
 };
 
 /**
-- 
1.7.9.5