basic type mechanism working

1 files changed, 27 insertions, 7 deletions

diff --git a/ffmpeg/libavformat/swfdec.c b/ffmpeg/libavformat/swfdec.c
index 54e0f6d..c95b18e 100644
--- a/ffmpeg/libavformat/swfdec.c
+++ b/ffmpeg/libavformat/swfdec.c
@@ -55,12 +55,18 @@ static int get_swf_tag(AVIOContext *pb, int *len_ptr)
 
 static int swf_probe(AVProbeData *p)
 {
+    if(p->buf_size < 15)
+        return 0;
+
     /* check file header */
-    if ((p->buf[0] == 'F' || p->buf[0] == 'C') && p->buf[1] == 'W' &&
-        p->buf[2] == 'S')
-        return AVPROBE_SCORE_MAX;
-    else
+    if (   AV_RB24(p->buf) != AV_RB24("CWS")
+        && AV_RB24(p->buf) != AV_RB24("FWS"))
         return 0;
+
+    if (p->buf[3] >= 20)
+        return AVPROBE_SCORE_MAX / 4;
+
+    return AVPROBE_SCORE_MAX;
 }
 
 #if CONFIG_ZLIB
@@ -440,16 +446,30 @@ bitmap_end_skip:
                 goto skip;
             if ((res = av_new_packet(pkt, len)) < 0)
                 return res;
-            avio_read(pb, pkt->data, 4);
+            if (avio_read(pb, pkt->data, 4) != 4) {
+                av_free_packet(pkt);
+                return AVERROR_INVALIDDATA;
+            }
             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;
-                avio_read(pb, pkt->data, pkt->size);
+                memset(pkt->data+pkt->size, 0, 4);
+                res = avio_read(pb, pkt->data, pkt->size);
             } else {
-                avio_read(pb, pkt->data + 4, pkt->size - 4);
+                res = avio_read(pb, pkt->data + 4, pkt->size - 4);
+                if (res >= 0)
+                    res += 4;
+            }
+            if (res != pkt->size) {
+                if (res < 0) {
+                    av_free_packet(pkt);
+                    return res;
+                }
+                av_shrink_packet(pkt, res);
             }
+
             pkt->pos = pos;
             pkt->stream_index = st->index;
             return pkt->size;