The show "NBA Basketball_WPTA-DT_28_01_2007_14_59_45.dvr-ms" is an example of the video stream being "stuck" on the first frame for a few seconds in the latest SVN (it last worked correctly in 7904). This show contains AC3 audio in the dvr-ms format. Since ffmpeg doesn't detect AC3 audio in the dvr-ms container the -an switch must be used.