Merge commit '7fbb3b5b'

* commit '7fbb3b5b':
  lavf: use the io_open callbacks for files opened from open_input() as well
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

libavformat/avformat.h

@@ -1841,9 +1841,9 @@ typedef struct AVFormatContext {
     /*
      * A callback for opening new IO streams.
      *
-     * Certain muxers or demuxers (e.g. for various playlist-based formats) need
-     * to open additional files during muxing or demuxing. This callback allows
-     * the caller to provide custom IO in such cases.
+     * Whenever a muxer or a demuxer needs to open an IO stream (typically from
+     * avformat_open_input() for demuxers, but for certain formats can happen at
+     * other times as well), it will call this callback to obtain an IO context.
      *
      * @param s the format context
      * @param pb on success, the newly opened IO context should be returned here