Can't get correct video duration with vp8enc

[tomw]

Hi,

launching a pipeline like:

gst-launch-1.0 videotestsrc ! videoconvert ! vp8enc ! webmmux ! filesink
location=/tmp/test.webm

and running it for a minute or so creates a video with the length of
almost 0 seconds:

Analyzing file:///tmp/test.webm
Done discovering file:///tmp/test.webm

Topology:
  container: video/webm
    video: video/x-vp8, width=(int)320, height=(int)240,
framerate=(fraction)25/1
      Codec:
        video/x-vp8, width=(int)320, height=(int)240,
framerate=(fraction)25/1
      Additional info:
        None
      Stream ID:
f834f283bce8aaa15f2c5dcb2a1e560b82cfcc48610d3bd3cfdf189db3bf3430/196999008
      Width: 320
      Height: 240
      Depth: 0
      Frame rate: 25/1
      Pixel aspect ratio: 1/1
      Interlaced: false
      Bitrate: 0
      Max bitrate: 0
      Tags:
        taglist, video-codec=(string)"VP8\ video",
container-format=(string)Matroska;
      

Properties:
  Duration: 0:00:00.233000000
  Seekable: yes
  Tags: 
      video codec: VP8 video
      container format: Matroska


any idea on how to fix this? Beyond this the pipeline runs as expected.
Playing with the various parameters for deadline and target-framerate
did not help either.

--tomw