support swink created files which have soi/eoi broken tags reversed

Originally committed as revision 10152 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/swf.c

@@ -734,8 +734,10 @@ static int swf_read_packet(AVFormatContext *s, AVPacket *pkt)
             get_le16(pb); /* BITMAP_ID */
             av_new_packet(pkt, len-2);
             get_buffer(pb, pkt->data, 4);
-            if (AV_RB32(pkt->data) == 0xffd8ffd9) {
+            if (AV_RB32(pkt->data) == 0xffd8ffd9 ||
+                AV_RB32(pkt->data) == 0xffd9ffd8) {
                 /* old SWF files containing SOI/EOI as data start */
+                /* files created by swink have reversed tag */
                 pkt->size -= 4;
                 get_buffer(pb, pkt->data, pkt->size);
             } else {