Help with rtsp camera configuration

I’ve got a (crappy) Stem Izon 2.0 camera that is providing an rtsp stream. I am able to connect and view the stream using VLC.

When I add the camera with the following configuration I get an “error loading image” in the frontend.

  - platform: ffmpeg
    input: -rtsp_transport tcp -i rtsp://admin:{REDACTED}@192.168.1.142:554/test_VGA
    name: izon
    ffmpeg_bin: /usr/bin/ffmpeg
    extra_arguments: -pred 1 -q:v 2

Based on similar threads, I’ve tried both ffmpeg and avconv installs.
Oddly enough, there is nothing in home-assistant.log about this at all (this is after restarting the service):

17-02-06 13:41:37 WARNING (Thread-6) [homeassistant.components.emulated_hue] Alexa type is deprecated and will be removed in a future version
17-02-06 13:41:40 WARNING (MainThread) [homeassistant.components.sensor.template] UndefinedError: 'None' has no attribute 'attributes'
17-02-06 13:41:40 WARNING (MainThread) [homeassistant.components.sensor.template] UndefinedError: 'None' has no attribute 'attributes'

Oddly, three hours after restarting the service, I do get some information about ffmpeg in the log:

17-02-06 16:57:16 WARNING (MainThread) [haffmpeg.core] FFmpeg isn't running!
Traceback (most recent call last):
  File "/home/hass/.homeassistant/deps/haffmpeg/core.py", line 114, in open
stderr=stderr
  File "/usr/lib/python3.4/asyncio/subprocess.py", line 226, in create_subprocess_exec
stderr=stderr, **kwds)
  File "/usr/lib/python3.4/asyncio/base_events.py", line 866, in subprocess_exec
bufsize, **kwargs)
  File "/usr/lib/python3.4/asyncio/unix_events.py", line 174, in _make_subprocess_transport
yield from transp._post_init()
  File "/usr/lib/python3.4/asyncio/base_subprocess.py", line 106, in _post_init
proc.stdin)
  File "/usr/lib/python3.4/asyncio/base_events.py", line 797, in connect_write_pipe
yield from waiter
  File "/usr/lib/python3.4/asyncio/futures.py", line 388, in __iter__
yield self  # This tells Task to wait for completion.
concurrent.futures._base.CancelledError
17-02-06 17:07:18 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/home/hass/.homeassistant/deps/aiohttp/web_server.py", line 61, in handle_request
 resp = yield from self._handler(request)
  File "/home/hass/.homeassistant/deps/aiohttp/web.py", line 249, in _handle
resp = yield from handler(request)
  File "/usr/lib/python3.4/asyncio/coroutines.py", line 143, in coro
res = yield from res
  File "/usr/lib/python3.4/asyncio/coroutines.py", line 143, in coro
res = yield from res
  File "/srv/hass/hass_venv/lib/python3.4/site-packages/homeassistant/components/http/__init__.py", line 427, in handle
result = yield from result
  File "/srv/hass/hass_venv/lib/python3.4/site-packages/homeassistant/components/camera/__init__.py", line 253, in get
response = yield from self.handle(request, camera)
  File "/srv/hass/hass_venv/lib/python3.4/site-packages/homeassistant/components/camera/__init__.py", line 272, in handle
image = yield from camera.async_camera_image()
  File "/srv/hass/hass_venv/lib/python3.4/site-packages/homeassistant/components/camera/ffmpeg.py", line 60, in async_camera_image
extra_cmd=self._extra_arguments)
  File "/home/hass/.homeassistant/deps/haffmpeg/tools.py", line 82, in get_image
image, _ = yield from self._proc.communicate()
AttributeError: 'NoneType' object has no attribute 'communicate'

ffmpeg is separate component from camera component
Example here
https://community.home-assistant.io/t/rtsp-support/2306/6