Hi Xavier, 

Following your recommendations I upgraded my env and retried a few mpegts movies after cleaning ~/.gstreamer-0.10 folder
Some mpeg-ts movies are well played but some others are not played for the same reason.  

Here is the output of gst-discoverer-0.10 on a failing movie (caps width and height not computed by the parsers) : 

$> GST_DEBUG=2 gst-discoverer-0.10 -v /media/NANO/ToyStory3_720P45M4_eng.mpg
Analyzing file:///media/NANO/ToyStory3_720P45M4_eng.mpg
0:00:00.393706954  3209   0x508f68 WARN       codecparsers_h264 gsth264parser.c:622:gst_h264_parse_vui_parameters: failed to read UE
0:00:00.393981612  3209   0x508f68 WARN       codecparsers_h264 gsth264parser.c:633:gst_h264_parse_vui_parameters: error parsing "VUI Parameters"
0:00:00.394073165  3209   0x508f68 WARN       codecparsers_h264 gsth264parser.c:1504:gst_h264_parse_sps: error parsing "Sequence parameter set"
0:00:00.394164718  3209   0x508f68 WARN       codecparsers_h264 gsth264parser.c:1539:gst_h264_parse_pps: couldn't find associated sequence parameter set with id: 0
0:00:00.394286788  3209   0x508f68 WARN       codecparsers_h264 gsth264parser.c:960:gst_h264_parser_parse_buffering_period: couldn't find associated sequence parameter set with id: 0
0:00:00.394439376  3209   0x508f68 WARN       codecparsers_h264 gsth264parser.c:1704:gst_h264_parser_parse_slice_hdr: couldn't find associated picture parameter set with id: 0
0:00:00.394561446  3209   0x508f68 WARN       codecparsers_h264 gsth264parser.c:1704:gst_h264_parser_parse_slice_hdr: couldn't find associated picture parameter set with id: 0
0:00:00.394683516  3209   0x508f68 WARN       codecparsers_h264 gsth264parser.c:1704:gst_h264_parser_parse_slice_hdr: couldn't find associated picture parameter set with id: 0
0:00:00.394775069  3209   0x508f68 WARN       codecparsers_h264 gsth264parser.c:1704:gst_h264_parser_parse_slice_hdr: couldn't find associated picture parameter set with id: 0
0:00:00.395324386  3209   0x508f68 WARN             mpegtsdemux gstmpegtsdemux.c:2865:gst_mpegts_demux_src_pad_query:<mpegtsdemux0> unsupported query format or no bitrate yet to approximate duration from bytes
0:00:00.410277999  3209   0x573940 WARN             mpegtsdemux gstmpegtsdemux.c:2865:gst_mpegts_demux_src_pad_query:<mpegtsdemux0> unsupported query format or no bitrate yet to approximate duration from bytes
0:00:00.422820724  3209   0x573940 WARN             mpegtsdemux gstmpegtsdemux.c:2865:gst_mpegts_demux_src_pad_query:<mpegtsdemux0> unsupported query format or no bitrate yet to approximate duration from bytes
0:00:00.516051925  3209   0x508f68 WARN                  ducati gstducatividdec.c:648:gst_ducati_viddec_sink_setcaps:<ducatih264dec0> missing required fields
0:00:00.518340743  3209   0x523d60 WARN                 basesrc gstbasesrc.c:2582:gst_base_src_loop:<source> error: Internal data flow error.
0:00:00.518493331  3209   0x523d60 WARN                 basesrc gstbasesrc.c:2582:gst_base_src_loop:<source> error: streaming task paused, reason not-negotiated (-4)
0:00:00.518829024  3209   0x3ce158 WARN              discoverer gstdiscoverer.c:1055:handle_message:<source> Got an error [debug:gstbasesrc.c(2582): gst_base_src_loop (): /GstPipeline:Discoverer/GstURIDecodeBin:discoverer-uri/GstFileSrc:source:
streaming task paused, reason not-negotiated (-4)], [message:Internal data flow error.]
0:00:00.519866622  3209   0x3ce158 WARN              discoverer gstdiscoverer.c:584:collect_stream_information: Couldn't get negotiated caps from discoverer-uri:src0

Done discovering file:///media/NANO/ToyStory3_720P45M4_eng.mpg
An error was encountered while discovering the file
 Internal data flow error.

Topology:
  container: video/mpegts, systemstream=(boolean)true, packetsize=(int)188
    audio: audio/mpeg, mpegversion=(int)1, mpegaudioversion=(int)1, layer=(int)2, rate=(int)44100, channels=(int)2, parsed=(boolean)true
      Codec:
        audio/mpeg, mpegversion=(int)1, mpegaudioversion=(int)1, layer=(int)2, rate=(int)44100, channels=(int)2, parsed=(boolean)true
      Additional info:
        None
      Channels: 2
      Sample rate: 44100
      Depth: 32
      Bitrate: 128000
      Max bitrate: 0
      Tags:
        taglist, audio-codec=(string)"MPEG\ 1\ Audio\,\ Layer\ 2", nominal-bitrate=(uint)128000, has-crc=(boolean)false, channel-mode=(string)stereo;
      
    video: video/x-h264, stream-format=(string)byte-stream, alignment=(string)nal
      Codec:
        video/x-h264, stream-format=(string)byte-stream, alignment=(string)nal
      Additional info:
        None
      Width: 0
      Height: 0
      Depth: 0
      Frame rate: 0/0
      Pixel aspect ratio: 1/1
      Interlaced: false
      Bitrate: 0
      Max bitrate: 0
      Tags:
        None
      
      video: video/x-h264, stream-format=(string)byte-stream, alignment=(string)au, parsed=(boolean)true
        Codec:
          video/x-h264, stream-format=(string)byte-stream, alignment=(string)au, parsed=(boolean)true
        Additional info:
          None
        Width: 0
        Height: 0
        Depth: 0
        Frame rate: 0/0
        Pixel aspect ratio: 1/1
        Interlaced: false
        Bitrate: 0
        Max bitrate: 0
        Tags:
          None
        

Properties:
  Duration: 0:20:01.206491627
  Seekable: yes
  Tags: 
      audio codec: MPEG 1 Audio, Layer 2
      nominal bitrate: 128000
      has crc: false
      channel mode: stereo
      layer: 2
      mode: stereo
      emphasis: none
      bitrate: 128000