minor tweaks

panda/src/movies/ffmpegVideoCursor.cxx

@@ -997,10 +997,30 @@ seek(int frame, bool backward) {
   PStatTimer timer(seek_pcollector);
 
   if (ffmpeg_support_seek) {
-    // Protect the call to av_seek_frame() in a global lock, just to be
-    // paranoid.
+    if (ffmpeg_global_lock) {
       ReMutexHolder av_holder(_av_lock);
+      do_seek(frame, backward);
+    } else {
+      do_seek(frame, backward);
+    }
 
+  } else {
+    // If seeking isn't supported, close-and-reopen.
+    if (backward) {
+      reset_stream();
+    }
+  }
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: FfmpegVideoCursor::do_seek
+//       Access: Private
+//  Description: As above, with the ffmpeg global lock held (if
+//               configured on).  Also only if ffmpeg-support-seek is
+//               on.
+////////////////////////////////////////////////////////////////////
+void FfmpegVideoCursor::
+do_seek(int frame, bool backward) {
   PN_int64 target_ts = (PN_int64)frame;
   if (target_ts < (PN_int64)(_initial_dts)) {
     // Attempts to seek before the first packet will fail.
@@ -1037,13 +1057,6 @@ seek(int frame, bool backward) {
 
   fetch_packet(0);
   fetch_frame(-1);
-
-  } else {
-    // If seeking isn't supported, close-and-reopen.
-    if (backward) {
-      reset_stream();
-    }
-  }
 }
 
 ////////////////////////////////////////////////////////////////////

panda/src/movies/ffmpegVideoCursor.h

@@ -130,6 +130,7 @@ private:
   void decode_frame(int &finished, AVPacket *packet);
   void do_decode_frame(int &finished, AVPacket *packet);
   void seek(int frame, bool backward);
+  void do_seek(int frame, bool backward);
   int binary_seek(int min_frame, int max_frame, int target_frame, int num_iterations);
   void advance_to_frame(int frame);
   void reset_stream();

panda/src/movies/ffmpegVirtualFile.cxx

@@ -217,6 +217,11 @@ register_protocol() {
   // function.
   av_register_all();
   
+  // And this one.
+#if LIBAVFORMAT_VERSION_INT >= 0x351400
+  avformat_network_init();
+#endif
+
   static URLProtocol protocol;
   protocol.name = "pandavfs";
   protocol.url_open  = pandavfs_open;