View source for Streaming Video With RaspberryPi

= General =

Caution: this is a Work in progress, things are being tested. The objective is to provide in the end one or more working solutions for everyone.

== Video streaming is a problem ==


The RaspberryPi camera offers an interesting solution to this problem. It is a very well integrated module of the Pi with one huge advantage: h264 encoding can be performed directly by the CPU as the camera uses the Serial Camera Interface protocol.

So theorically, solving the video problem with the Pi is easy but there are many subtle problems.


== Problems ==


'''Audio''' As we use video webstreaming mostly for conferences broadcasting, good audio quality is necessary.

'''Slides''' It would be interesting to include slides of conferences while filming.

'''File''' It is important to have a file at the end of the filming.

'''Web''' It is important to have a large viewer base, therefore a well supported format.


== Raspicam basics ==

http://elinux.org/Rpi_Camera_Module

raspivid is the basic command line used to capture video in h264.

<code>raspivid -t 3 -fps 25 -b 1000k -w 1920 -h 1080 -o /tmp/video.h264</code>

A very simple tutorial : http://www.raspberrypi-spy.co.uk/2013/05/capturing-hd-video-with-the-pi-camera-module/
= Solution =

== Solution 1 : OGG/VORBIS + Icecast ==


'''Basic idea''' use the PI to capture MP4, stream it locally to a laptop. Merge audio in the laptop with ffmpeg and push the resulting ogg/vorbis stream to an icecast server.

'''CON''' Mandatory local network between pi and laptop for socket, 

'''PRO''' Icecast is simple, open, and handles authentification. The file is saved on the server. Vorbis is HTML5 compatible. 

'''Sources'''

http://sirlagz.net/2013/01/07/how-to-stream-a-webcam-from-the-raspberry-pi-part-3/


'''POC'''

'''A.''' Compile FFMPEG on pi & server

'''B.''' Start capture in a screen

    <code>cd /tmp/capture && rm -f ./* && /usr/local/bin/ffmpeg -f v4l2 -framerate 25 -video_size 320x240  -i /dev/video0 -f segment -segment_list out.list -segment_list_flags +live -segment_time 3 %4d.ts</code>

'''C.''' Run rsync to server in a screen

    <code> while true; do rsync -a /tmp/capture user@server:/tmp/; sleep 1; done</code>

'''D.''' Broadcast from server to icecast 

This requires 
# a PHP streamer for your incoming files : http://pastebin.com/3f5t9vDS
# the oggfwd command line tool  

    <code > php /usr/local/bin/stream.php | ffmpeg -i - -f ogg - | oggfwd -p -n "Test" stream.server.com 8000 mySecretIceCastStreamingPassword /test </code>


== Solution 2 : FLVSTR + PHP Streamer ==


'''Basic idea''' the Octopuce company has a solution to convert live MP4 to F4V. With an USB audio card, we could mux the MP4 and AAC audio and have a standalone solution.

'''CON''' authentification is hard, F4V means Flash, requires an USB disk for local backup

'''PRO''' the pi can be autonomous

First, authentification. This problem is adressed by solving encryption as well: we use an SSL socket to communicate with the server.



== Solution 3 : RTSP ==

'''Basic idea''' Use an RTSP stream with VLC and the V4L driver

'''CON''' Non commercial RTSP server are not the norm, requires VLC or Flash player, Quality with v4l is low
 
'''PRO''' Easy to work out

'''Sources''' 

http://www.ics.com/blog/raspberry-pi-camera-module#.VJFhbyvF-b8

http://raspberrypi.stackexchange.com/questions/23182/how-to-stream-video-from-raspberry-pi-camera-and-watch-it-live

http://ffmpeg.gusari.org/viewtopic.php?f=16&t=1130

http://blog.tkjelectronics.dk/2013/06/how-to-stream-video-and-audio-from-a-raspberry-pi-with-no-latency/

== Solution 4 : HLS + RSYNC ==


'''Basic idea''' Use HLS segmentation and rsync

'''CON''' Not all web players can do HLS
 
'''PRO''' Almost out of the box, robust

'''Howto'''

1. Compile fresh ffmpeg on the pi :
<pre>

sudo -s
cd /usr/src 
git clone --depth 1 git://source.ffmpeg.org/ffmpeg.git 
cd ffmpeg
./configure --enable-gpl --enable-libx264
make
make install</pre>

Note : compiler ffmpef sur le serveur 
<pre> aptitude install libass-dev libavcodec-extra libfdk-aac-dev libmp3lame-dev libopus-dev libtheora-dev libvorbis-dev libvpx-dev pkg-config yasm
./configure --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora \
--enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-x11grab
</pre>

2. Run a capture : <code>raspivid -t 0 -b 1000000 -w 1080 -h 720 -v -o - | ffmpeg -i - -f alsa -ac 1 -itsoffset 6.5 -i hw:1 -acodec aac -strict -2 -vcodec copy out.m3u8 </code>

3. Run a cron rsync to server (todo)

4. Connect a client (todo)


'''Sources''' 

http://www.ffmpeg.org/ffmpeg-formats.html#hls

== References ==


http://techzany.com/2013/09/live-streaming-video-using-avconv-and-a-raspberry-pi/


https://trac.ffmpeg.org/wiki/StreamingGuide


'''Node'''
http://phoboslab.org/log/2013/09/html5-live-video-streaming-via-websockets
https://github.com/fluent-ffmpeg/node-fluent-ffmpeg

http://ffmpeg.org/ffmpeg-all.html#segment_002c-stream_005fsegment_002c-ssegment