Need help playing an FFV1 encoded video file

[Patrick Doyle]

Hello,
I have a (several, actually) video file that was losslessly encoded
with FFv1.  avconv reports:

$ avconv -i data/20141022.d.run1000big.movavconv version
9.16-6:9.16-0ubuntu0.14.04.1, Copyright (c) 2000-2014 the Libav
developers
  built on Aug 10 2014 18:16:02 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'data/20141022.d.run1000big.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    encoder         : Lavf54.20.4
  Duration: 00:05:12.83, start: 0.000000, bitrate: 23789 kb/s
    Stream #0.0(eng): Video: ffv1, gray, 640x480, 23787 kb/s, 30 fps,
30 tbr, 30 tbn
At least one output file must be specified

But when I try to play it using playbin, I get:

$ gst-launch-1.0 playbin uri=file:///.../data/20141022.d.run1000big.mov
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
Missing element: video/x-gst-fourcc-FFV1 decoder
WARNING: from element
/GstPlayBin:playbin0/GstURIDecodeBin:uridecodebin0: No decoder
available for type 'video/x-gst-fourcc-FFV1, width=(int)640,
height=(int)480, framerate=(fraction)30/1,
pixel-aspect-ratio=(fraction)1/1'.
Additional debug info:
gsturidecodebin.c(930): unknown_type_cb ():
/GstPlayBin:playbin0/GstURIDecodeBin:uridecodebin0
ERROR: from element
/GstPlayBin:playbin0/GstURIDecodeBin:uridecodebin0/GstDecodeBin:decodebin0:
Your GStreamer installation is missing a plug-in.
Additional debug info:
gstdecodebin2.c(3928): gst_decode_bin_expose ():
/GstPlayBin:playbin0/GstURIDecodeBin:uridecodebin0/GstDecodeBin:decodebin0:
no suitable plugins found
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
Freeing pipeline ...

The error reported is "No decoder available for type
'video/x-gst-fourcc-FFV1'".  Can anybody point me in a direction to
figure out how to debug this?

Thanks.

--wpd