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• Use deck.js as a remote presentation tool

  8 janvier 2014, par silvia

  deck.js is one of the new HTML5-based presentation tools. It’s simple to use, in particular for your basic, every-day presentation needs. You can also create more complex slides with animations etc. if you know your HTML and CSS.

  Yesterday at linux.conf.au (LCA), I gave a presentation using deck.js. But I didn’t give it from the lectern in the room in Perth where LCA is being held – instead I gave it from the comfort of my home office at the other end of the country.

  I used my laptop with in-built webcam and my Chrome browser to give this presentation. Beforehand, I had uploaded the presentation to a Web server and shared the link with the organiser of my speaker track, who was on site in Perth and had set up his laptop in the same fashion as myself. His screen was projecting the Chrome tab in which my slides were loaded and he had hooked up the audio output of his laptop to the room speaker system. His camera was pointed at the audience so I could see their reaction.

  I loaded a slide master URL :
  http://html5videoguide.net/presentations/lca_2014_webrtc/?master
  and the room loaded the URL without query string :
  http://html5videoguide.net/presentations/lca_2014_webrtc/.

  Then I gave my talk exactly as I would if I was in the same room. Yes, it felt exactly as though I was there, including nervousness and audience feedback.

  How did we do that ? WebRTC (Web Real-time Communication) to the rescue, of course !

  We used one of the modules of the rtc.io project called rtc-glue to add the video conferencing functionality and the slide navigation to deck.js. It was actually really really simple !

  Here are the few things we added to deck.js to make it work :

  • Code added to index.html to make the video connection work :

    <meta name="rtc-signalhost" content="http://rtc.io/switchboard/">
    
    <meta name="rtc-room" content="lca2014">
    
    ...
    
    <video id="localV" rtc-capture="camera" muted></video>
    
    <video id="peerV" rtc-peer rtc-stream="localV"></video>
    
    ...
    
    <script src="glue.js"></script>
    
    <script>
    
    glue.config.iceServers = [{ url: 'stun:stun.l.google.com:19302' }];
    
    </script>

    The iceServers config is required to punch through firewalls – you may also need a TURN server. Note that you need a signalling server – in our case we used http://rtc.io/switchboard/, which runs the code from rtc-switchboard.

  • Added glue.js library to deck.js :

    Downloaded from https://raw.github.com/rtc-io/rtc-glue/master/dist/glue.js into the source directory of deck.js.

  • Code added to index.html to synchronize slide navigation :

    glue.events.once('connected', function(signaller) {
    
      if (location.search.slice(1) !== '') {
    
        $(document).bind('deck.change', function(evt, from, to) {
    
          signaller.send('/slide', {
    
            idx: to,
    
            sender: signaller.id
    
          });
    
        });
    
      }
    
      signaller.on('slide', function(data) {
    
        console.log('received notification to change to slide: ', data.idx);
    
        $.deck('go', data.idx);
    
      });
    
    });

    This simply registers a callback on the slide master end to send a slide position message to the room end, and a callback on the room end that initiates the slide navigation.

  And that’s it !

  You can find my slide deck on GitHub.

  Feel free to write your own slides in this manner – I would love to have more users of this approach. It should also be fairly simple to extend this to share pointer positions, so you can actually use the mouse pointer to point to things on your slides remotely. Would love to hear your experiences !

  Note that the slides are actually a talk about the rtc.io project, so if you want to find out more about these modules and what other things you can do, read the slide deck or watch the talk when it has been published by LCA.

  Many thanks to Damon Oehlman for his help in getting this working.

  BTW : somebody should really fix that print style sheet for deck.js – I’m only ever getting the one slide that is currently showing.

• how to install and run phpize

  13 décembre 2016, par Hrishikesh Choudhari

  I have been meaning to install ffmpeg as an extension to my php setup. So before I can install it, I need to phpize it. I installed php5-dev by sudo apt-get install php5-dev But now when I run phpize I get the following error :

  phpize
  
  Cannot find config.m4. 
  
  Make sure that you run '/usr/bin/phpize' in the top level source directory of the module

  The location of my php.ini is /usr/local/zend/etc/php.ini

  From another online resource i tried this

  sudo apt-get install autoconf automake libtool m4

  But all of them are already installed.

  Locate config.m4 didnt return anything.

  Any pointers here how I can get phpize and thus, ffmpeg up and running ?

• ffmpeg ffserver - create a mosaic from two 720p webcam feeds

  28 juillet 2015, par der_felix

  for a project i would like to take the video feeds (NO audio) of two logitech c920 webcams, put them side-by-side and stream them.
  the c920 is able to compress the video feed with h264 itself(if enabled) and delivers 1080p with upto 30fps.
  the stream is then loaded in an android app by a ffmpeg library and rendered to the screen.

  what i already know :
  i know that i can take multiple streams or input files and create a mosaic stream via the filter_complex module.
  http and h264 seem to be good for streaming, but other configurations are also welcom if they are faster/better.

  the question :
  but how can i start the cameras with v4l2, set the camera resoltution and camera internal encoding and use these streams to create the mosaic ?
  the mosaic should be unscaled (=2560x720px).

  and i very often get the error code 256 but didnt find a solution what it means.

  the system : laptop with usb3, ubuntu 15.04x64 ffmpeg 2.7.1 and ffserver 2.5.7

  thanks for your help

  ffserver config :

  HTTPPort 8080                
  
  HTTPBindAddress 0.0.0.0      
  
  MaxHTTPConnections 2000   
  
  MaxClients 1000         
  
  MaxBandwidth 50000
  
  CustomLog -      
  
  #NoDaemon       
  
  
  
  <feed>         
  
  
  
  File /tmp/feed1.ffm
  
  Launch ffmpeg -f v4l2 - input_format h264 -i /dev/video0 -i /dev/video1 -size 1280x720 -r 30 -filter_complex "nullsrc=size=2560x720 [base]; [0:v] setpts=PTS-STARTPTS [left]; [1:v] setpts=PTS-STARTPTS [right]; [base][left] overlay=shortest=1 [tmp1]; [tmp1][right] overlay=shortest=1:x=1280"  -c:v libx264 -f mpegts
  
  
  
  </feed>
  
  
  
  <stream>
  
  
  
  Feed feed1.ffm
  
  Format mpegts      
  
  VideoBitRate 1024   
  
  #VideoBufferSize 1024
  
  VideoFrameRate 30      
  
  #VideoSize hd720      
  
  VideoSize 2560x720
  
  #VideoIntraOnly         
  
  #VideoGopSize 12      
  
  VideoCodec libx264      
  
  NoAudio            
  
  VideoQMin 3         
  
  VideoQMax 31
  
  NoDefaults
  
  
  
  </stream>
  
  
  
  <stream>        
  
     Format status
  
     #Only allow local people to get the status
  
     ACL allow localhost
  
     ACL allow 192.168.0.0 192.168.255.255
  
  </stream>

  output :

  ubuntu@ubuntu:~$ ffserver
  
  ffserver version 2.5.7-0ubuntu0.15.04.1 Copyright (c) 2000-2015 the FFmpeg developers
  
    built with gcc 4.9.2 (Ubuntu 4.9.2-10ubuntu13)
  
    configuration: --prefix=/usr --extra-version=0ubuntu0.15.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --shlibdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --enable-shared --disable-stripping --enable-avresample --enable-avisynth --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libshine --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libwavpack --enable-libwebp --enable-libxvid --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzvbi --enable-libzmq --enable-frei0r --enable-libvpx --enable-libx264 --enable-libsoxr --enable-gnutls --enable-openal --enable-libopencv --enable-librtmp --enable-libx265
  
    libavutil      54. 15.100 / 54. 15.100
  
    libavcodec     56. 13.100 / 56. 13.100
  
    libavformat    56. 15.102 / 56. 15.102
  
    libavdevice    56.  3.100 / 56.  3.100
  
    libavfilter     5.  2.103 /  5.  2.103
  
    libavresample   2.  1.  0 /  2.  1.  0
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Tue Jul 28 10:13:44 2015 FFserver started.
  
  Tue Jul 28 10:13:44 2015 Launch command line: ffmpeg -f v4l2 - input_format h264 -i /dev/video0 -i /dev/video1 -size 1280x720 -r 30 -filter_complex nullsrc=size=2560x720 [base]; [0:v] setpts=PTS-STARTPTS [left]; [1:v] setpts=PTS-STARTPTS [right]; [base][left] overlay=shortest=1 [tmp1]; [tmp1][right] overlay=shortest=1:x=1280 -c:v libx264 -f mpegts http://127.0.0.1:8080/feed1.ffm
  
  feed1.ffm: Pid 17388 exited with status 256 after 0 seconds

  Hey guys !

  Here is our plan b for the mosaic stream.

  Alternative config :

  HTTPPort 8080         
  
  HTTPBindAddress 0.0.0.0   
  
  MaxHTTPConnections 2000   
  
  MaxClients 1000         
  
  MaxBandwidth 50000      
  
  CustomLog -         
  
  
  
  <feed>
  
  File /tmp/feedlinks.ffm
  
  Launch ffmpeg -f v4l2 -input_format h264 -vcodec h264 -i /dev/video0 -video_size 1280x720 -r 30
  
  </feed>
  
  
  
  <feed>
  
  File /tmp/feedrechts.ffm
  
  Launch ffmpeg -f v4l2 -input_format h264 -vcodec h264 -i /dev/video1 -video_size 1280x720 -r 30 
  
  </feed>
  
  
  
  <stream>
  
  Feed feedlinks.ffm
  
  Format mpegts
  
  VideoBitRate 512
  
  VideoFrameRate 30
  
  VideoSize hd720
  
  VideoCodec libx264
  
  NoAudio
  
  VideoQMin 3
  
  VideoQMax 31
  
  </stream>
  
  
  
  <stream>
  
  Feed feedrechts.ffm
  
  Format mpegts
  
  VideoBitRate 512
  
  VideoFrameRate 30
  
  VideoSize hd720
  
  VideoCodec libx264
  
  NoAudio
  
  VideoQMin 3
  
  VideoQMax 31
  
  </stream>
  
  
  
  <feed>
  
  File /tmp/feedmosaic.ffm
  
  Launch ffmpeg -i http://localhost:8080/testlinks.mpg -i http://localhost:8080/testrechts.mpg -filter_complex "nullsrc=size=2560x720 [base]; [0:v] setpts=PTS-STARTPTS [left]; [1:v] setpts=PTS-STARTPTS [right]; [base][left] overlay=shortest=1 [tmp1]; [tmp1][right] overlay=shortest=1:x=1280" -c:v libx264 -preset ultrafast -f mpegts
  
  </feed>
  
  
  
  <stream>
  
  Feed feedmosaic.ffm
  
  Format mpegts         # Format of the stream
  
  VideoFrameRate 30      # Number of frames per second
  
  VideoSize 2560x720
  
  VideoCodec libx264      # Choose your codecs.
  
  NoAudio            # Suppress audio
  
  VideoQMin 3         # Videoquality ranges from 1 - 31 (worst to best)
  
  VideoQMax 31
  
  NoDefaults
  
  </stream>
  
  
  
  <stream>           # Server status URL
  
     Format status
  
     # Only allow local people to get the status
  
     ACL allow localhost
  
     ACL allow 192.168.0.0 192.168.255.255
  
     ACL allow 192.168.178.0 192.168.255.255
  
  </stream>

  And this is the new output :

  ubuntu@ubuntu:~$ ffserver
  
  ffserver version 2.5.7-0ubuntu0.15.04.1 Copyright (c) 2000-2015 the FFmpeg developers
  
    built with gcc 4.9.2 (Ubuntu 4.9.2-10ubuntu13)
  
    configuration: --prefix=/usr --extra-version=0ubuntu0.15.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --shlibdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --enable-shared --disable-stripping --enable-avresample --enable-avisynth --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libshine --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libwavpack --enable-libwebp --enable-libxvid --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzvbi --enable-libzmq --enable-frei0r --enable-libvpx --enable-libx264 --enable-libsoxr --enable-gnutls --enable-openal --enable-libopencv --enable-librtmp --enable-libx265
  
    libavutil      54. 15.100 / 54. 15.100
  
    libavcodec     56. 13.100 / 56. 13.100
  
    libavformat    56. 15.102 / 56. 15.102
  
    libavdevice    56.  3.100 / 56.  3.100
  
    libavfilter     5.  2.103 /  5.  2.103
  
    libavresample   2.  1.  0 /  2.  1.  0
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  /etc/ffserver.conf:44: Setting default value for video bit rate tolerance = 128000. Use NoDefaults to disable it.
  
  /etc/ffserver.conf:44: Setting default value for video rate control equation = tex^qComp. Use NoDefaults to disable it.
  
  /etc/ffserver.conf:44: Setting default value for video max rate = 1024000. Use NoDefaults to disable it.
  
  /etc/ffserver.conf:44: Setting default value for video buffer size = 1024000. Use NoDefaults to disable it.
  
  /etc/ffserver.conf:61: Setting default value for video bit rate tolerance = 128000. Use NoDefaults to disable it.
  
  /etc/ffserver.conf:61: Setting default value for video rate control equation = tex^qComp. Use NoDefaults to disable it.
  
  /etc/ffserver.conf:61: Setting default value for video max rate = 1024000. Use NoDefaults to disable it.
  
  /etc/ffserver.conf:61: Setting default value for video buffer size = 1024000. Use NoDefaults to disable it.
  
  Tue Jul 28 11:13:01 2015 Codec bitrates do not match for stream 0
  
  Tue Jul 28 11:13:01 2015 FFserver started.
  
  Tue Jul 28 11:13:01 2015 Launch command line: ffmpeg -f v4l2 -input_format h264 -vcodec h264 -i /dev/video0 -video_size 1280x720 -r 30 http://127.0.0.1:8080/feedlinks.ffm
  
  Tue Jul 28 11:13:01 2015 Launch command line: ffmpeg -f v4l2 -input_format h264 -vcodec h264 -i /dev/video1 -video_size 1280x720 -r 30 http://127.0.0.1:8080/feedrechts.ffm
  
  Tue Jul 28 11:13:01 2015 Launch command line: ffmpeg -i http://localhost:8080/testlinks.mpg -i http://localhost:8080/testrechts.mpg -filter_complex nullsrc=size=2560x720 [base]; [0:v] setpts=PTS-STARTPTS [left]; [1:v] setpts=PTS-STARTPTS [right]; [base][left] overlay=shortest=1 [tmp1]; [tmp1][right] overlay=shortest=1:x=1280 -c:v libx264 -preset ultrafast -f mpegts http://127.0.0.1:8080/feedmosaic.ffm
  
  Tue Jul 28 11:13:02 2015 127.0.0.1 - - [GET] "/feedlinks.ffm HTTP/1.1" 200 4175
  
  Tue Jul 28 11:13:02 2015 127.0.0.1 - - [GET] "/feedrechts.ffm HTTP/1.1" 200 4175
  
  Tue Jul 28 11:13:18 2015 127.0.0.1 - - [POST] "/feedmosaic.ffm HTTP/1.1" 200 4096
  
  Tue Jul 28 11:13:18 2015 127.0.0.1 - - [GET] "/testlinks.mpg HTTP/1.1" 200 2130291
  
  Tue Jul 28 11:13:18 2015 127.0.0.1 - - [GET] "/testrechts.mpg HTTP/1.1" 200 1244999
  
  feedmosaic.ffm: Pid 18775 exited with status 256 after 17 seconds

  Thanks for your help !