avformat/riffdec: ask for samples with wav header size < 14

Based on commit by Hendrik Leppkes <h.leppkes@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/riffdec.c

@@ -84,6 +84,9 @@ int ff_get_wav_header(AVIOContext *pb, AVCodecContext *codec, int size)
 {
     int id;
 
+    if (size < 14)
+        avpriv_request_sample(codec, "wav header size < 14");
+
     id                 = avio_rl16(pb);
     codec->codec_type  = AVMEDIA_TYPE_AUDIO;
     codec->channels    = avio_rl16(pb);