optional ISO 639 3 letter language field

Originally committed as revision 4348 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/avformat.h

@@ -5,7 +5,7 @@
 extern "C" {
 #endif
 
-#define LIBAVFORMAT_BUILD       4625
+#define LIBAVFORMAT_BUILD       4626
 
 #define LIBAVFORMAT_VERSION_INT FFMPEG_VERSION_INT
 #define LIBAVFORMAT_VERSION     FFMPEG_VERSION
@@ -248,6 +248,8 @@ typedef struct AVStream {
        seconds. */
     int64_t duration;
 
+    char language[4]; /* ISO 639 3-letter language code (empty string if undefined) */
+
     /* av_read_frame() support */
     int need_parsing;
     struct AVCodecParserContext *parser;