Avcodec: map teletext IDs

Close #5204

modules/codec/avcodec/fourcc.c

@@ -417,6 +417,9 @@ static const struct
     { VLC_CODEC_SUBT, CODEC_ID_TEXT, SPU_ES },
     { VLC_CODEC_XSUB, CODEC_ID_XSUB, SPU_ES },
     { VLC_CODEC_SSA, CODEC_ID_SSA, SPU_ES },
+#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT( 52, 38, 0 )
+    { VLC_CODEC_TELETEXT, CODEC_ID_DVB_TELETEXT, SPU_ES },
+#endif
 
     { 0, 0, UNKNOWN_ES }
 };