@@ -70,6 +70,8 @@ static int64_t io_seek(void *opaque, int64_t offset, int whence)

         if (offset > INT64_MAX - c->filesize)

             return -1;

         offset += c->filesize;

+    } else if (whence == AVSEEK_SIZE) {

+        return c->filesize;

     }

     if (offset < 0 || offset > c->filesize)

         return -1;