Streaming worked for me with the following setup
ffserver -f binary/ffserver.conf gphoto2 --capture-movie --stdout | ffmpeg -f mjpeg -re -i pipe:0 http://localhost:5000/feed1.ffm
with the stream appearing at http://localhost:5000/stat.html
#ffserver.conf
HttpPort 5000
MaxHTTPConnections 200
MaxClients 10
MaxBandwidth 1000000
<Feed feed1.ffm>
File /tmp/feed1.ffm
FileMaxSize 5M
</Feed>
<Stream test.mjpg>
Feed feed1.ffm
Format mpjpeg
VideoSize 640x480
VideoFrameRate 15
VideoBitRate 1024
VideoBufferSize 40
VideoIntraOnly
NoAudio
Strict -1
</Stream>
<Stream index.html>
Format status
</Stream>