I use this pipe to decode dvd dump:
gst-launch-1.0  -v filesrc location=../stream.dump ! mpegpsdemux name=demux demux.video_e0 ! mpegvideoparse ! mpeg2dec ! fakesink

for some wersions it worked without problems but now i get fallowing error:
** (gst-launch-1.0:4826): CRITICAL **: gst_video_decoder_allocate_output_frame: assertion 'frame->output_buffer == NULL' failed
ERROR: from element /GstPipeline:pipeline0/GstMpegPSDemux:demux: Internal data stream error.
Additional debug info:
gstmpegdemux.c(2937): gst_flups_demux_loop (): /GstPipeline:pipeline0/GstMpegPSDemux:demux:
stream stopped, reason error

as workaround i replaced mpeg2dec with avdec_mpeg2video. It works but periodically i get this errors:
0:16:16.289976290  4584      0x1592b20 ERROR                  libav :0:: get_buffer() failed (-1 2 (nil))
0:16:16.290095159  4584      0x1592b20 ERROR                  libav :0:: warning: first frame is no keyframe
0:16:16.290139508  4584      0x1592b20 ERROR                  libav :0:: get_buffer() failed (-1 2 (nil))
0:16:22.511200089  4584      0x1592b20 ERROR                  libav :0:: get_buffer() failed (-1 2 (nil))
0:16:22.511317004  4584      0x1592b20 ERROR                  libav :0:: warning: first frame is no keyframe
0:16:22.511334394  4584      0x1592b20 ERROR                  libav :0:: get_buffer() failed (-1 2 (nil))
0:16:39.176169708  4584      0x1592b20 ERROR                  libav :0:: get_buffer() failed (-1 2 (nil))


Right not i was not able to locate where exactly the problem is, mpegpsdemux, mpegvideoparse or mpeg2dec.