-vcodec copy fix patch by (mru at users dot sourceforge dot net (Måns Rullgård))

Originally committed as revision 1114 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffmpeg.c

@@ -1290,6 +1290,7 @@ static int av_encode(AVFormatContext **output_files,
                         /* no reencoding needed : output the packet directly */
                         /* force the input stream PTS */
                         av_write_frame(os, ost->index, data_buf, data_size);
+			ost->st->codec.frame_number++;
                     }
                 }
             }