stream_filter: split out code for automatic filter probing

src/input/input.c

@@ -2309,6 +2309,8 @@ static int InputSourceInit( input_thread_t *p_input,
         }
 
         /* Add stream filters */
+        p_stream = stream_FilterAutoNew( p_stream );
+
         char *psz_stream_filter = var_GetNonEmptyString( p_input,
                                                          "stream-filter" );
         p_stream = stream_FilterChainNew( p_stream, psz_stream_filter,

src/input/stream.h

@@ -46,11 +46,18 @@ stream_t *stream_AccessNew( access_t *p_access );
 stream_t *stream_FilterNew( stream_t *p_source,
                             const char *psz_stream_filter );
 
+/**
+ * Automatically wraps a stream with any applicable stream filter.
+ * @return the (outermost/downstream) stream filter; if no filters were added,
+ * then the function return the source parameter.
+ * @note The function never returns NULL.
+ */
+stream_t *stream_FilterAutoNew( stream_t *source ) VLC_USED;
+
 /**
  * This function creates a chain of filters:
- * - first, automatic probed stream filters are inserted.
- * - then, optional user filters (configured by psz_chain) are inserted.
- * - finaly, an optional record filter is inserted if b_record is true.
+ * - optional user filters (configured by psz_chain) are inserted.
+ * - an optional record filter is inserted if b_record is true.
  *
  * You must release the returned value using stream_Delete unless it is used as a
  * source to another filter.

src/input/stream_filter.c

@@ -73,21 +73,25 @@ stream_t *stream_FilterNew( stream_t *p_source,
     return s;
 }
 
-stream_t *stream_FilterChainNew( stream_t *p_source,
-                                 const char *psz_chain,
-                                 bool b_record )
+/* Add automatic stream filter */
+stream_t *stream_FilterAutoNew( stream_t *p_source )
 {
-    /* Add auto stream filter */
     for( ;; )
     {
         stream_t *p_filter = stream_FilterNew( p_source, NULL );
-        if( !p_filter )
+        if( p_filter == NULL )
             break;
 
-        msg_Dbg( p_filter, "Inserted a stream filter" );
+        msg_Dbg( p_filter, "stream filter added to %p", p_source );
         p_source = p_filter;
     }
+    return p_source;
+}
 
+stream_t *stream_FilterChainNew( stream_t *p_source,
+                                 const char *psz_chain,
+                                 bool b_record )
+{
     /* Add user stream filter */
     char *psz_tmp = psz_chain ? strdup( psz_chain ) : NULL;
     char *psz = psz_tmp;