set keyframe flag for au/wav patch by (Nathan Kurz <nate at verse dot com>)

Originally committed as revision 3596 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/au.c

@@ -163,6 +163,7 @@ static int au_read_packet(AVFormatContext *s,
     if (av_new_packet(pkt, MAX_SIZE))
         return AVERROR_IO;
     pkt->stream_index = 0;
+    pkt->flags |= PKT_FLAG_KEY;    
 
     ret = get_buffer(&s->pb, pkt->data, pkt->size);
     if (ret < 0)

libavformat/wav.c

@@ -329,6 +329,7 @@ static int wav_read_packet(AVFormatContext *s,
     if (av_new_packet(pkt, size))
         return AVERROR_IO;
     pkt->stream_index = 0;
+    pkt->flags |= PKT_FLAG_KEY;    
 
     ret = get_buffer(&s->pb, pkt->data, pkt->size);
     if (ret < 0)