avformat/mov: Simplify format checking code

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/mov.c

@@ -1812,16 +1812,9 @@ static void mov_parse_stsd_audio(MOVContext *c, AVIOContext *pb,
                                  AVStream *st, MOVStreamContext *sc)
 {
     int bits_per_sample, flags;
-    uint32_t format;
+    uint16_t version = avio_rb16(pb);
-    uint16_t version;
     AVDictionaryEntry *compatible_brands = av_dict_get(c->fc->metadata, "compatible_brands", NULL, AV_DICT_MATCH_CASE);
 
-    avio_seek(pb, -12, SEEK_CUR);
-    format = avio_rb32(pb);
-    avio_seek(pb, 8, SEEK_CUR);
-
-    version = avio_rb16(pb);
-
     avio_rb16(pb); /* revision level */
     avio_rb32(pb); /* vendor */
 
@@ -1870,7 +1863,7 @@ static void mov_parse_stsd_audio(MOVContext *c, AVIOContext *pb,
         }
     }
 
-    if (format == 0) {
+    if (sc->format == 0) {
         if (st->codec->bits_per_coded_sample == 8)
             st->codec->codec_id = mov_codec_id(st, MKTAG('r','a','w',' '));
         else if (st->codec->bits_per_coded_sample == 16)