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• Neutral net or neutered

  4 juin 2013, par Mans — Law and liberty

  In recent weeks, a number of high-profile events, in the UK and elsewhere, have been quickly seized upon to promote a variety of schemes for monitoring or filtering Internet access. These proposals, despite their good intentions of protecting children or fighting terrorism, pose a serious threat to fundamental liberties. Although at a glance the ideas may seem like a reasonable price to pay for the prevention of some truly hideous crimes, there is more than first meets the eye. Internet regulation in any form whatsoever is the thin end of a wedge at whose other end we find severely restricted freedom of expression of the kind usually associated with oppressive dictatorships. Where the Internet was once a novelty, it now forms an integrated part of modern society ; regulating the Internet means regulating our lives.

  Terrorism

  Following the brutal murder of British soldier Lee Rigby in Woolwich, attempts were made in the UK to revive the controversial Communications Data Bill, also dubbed the snooper’s charter. The bill would give police and security services unfettered access to details (excluding content) of all digital communication in the UK without needing so much as a warrant.

  The powers afforded by the snooper’s charter would, the argument goes, enable police to prevent crimes such as the one witnessed in Woolwich. True or not, the proposal would, if implemented, also bring about infrastructure for snooping on anyone at any time for any purpose. Once available, the temptation may become strong to extend, little by little, the legal use of these abilities to cover ever more everyday activities, all in the name of crime prevention, of course.

  In the emotional aftermath of a gruesome act, anything with the promise of preventing it happening again may seem like a good idea. At times like these it is important, more than ever, to remain rational and carefully consider all the potential consequences of legislation, not only the intended ones.

  Hate speech

  Hand in hand with terrorism goes hate speech, preachings designed to inspire violence against people of some singled-out nation, race, or other group. Naturally, hate speech is often to be found on the Internet, where it can reach large audiences while the author remains relatively protected. Naturally, we would prefer for it not to exist.

  To fulfil the utopian desire of a clean Internet, some advocate mandatory filtering by Internet service providers and search engines to remove this unwanted content. Exactly how such censoring might be implemented is however rarely dwelt upon, much less the consequences inadvertent blocking of innocent material might have.

  Pornography

  Another common target of calls for filtering is pornography. While few object to the blocking of child pornography, at least in principle, the debate runs hotter when it comes to the legal variety. Pornography, it is claimed, promotes violence towards women and is immoral or generally offensive. As such it ought to be blocked in the name of the greater good.

  The conviction last week of paedophile Mark Bridger for the abduction and murder of five-year-old April Jones renewed the debate about filtering of pornography in the UK ; his laptop was found to contain child pornography. John Carr of the UK government’s Council on Child Internet Safety went so far as suggesting a default blocking of all pornography, access being granted to an Internet user only once he or she had registered with some unspecified entity. Registering people wishing only to access perfectly legal material is not something we do in a democracy.

  The reality is that Google and other major search engines already remove illegal images from search results and report them to the appropriate authorities. In the UK, the Internet Watch Foundation, a non-government organisation, maintains a blacklist of what it deems ‘potentially criminal’ content, and many Internet service providers block access based on this list.

  While well-intentioned, the IWF and its blacklist should raise some concerns. Firstly, a vigilante organisation operating in secret and with no government oversight acting as the nation’s morality police has serious implications for freedom of speech. Secondly, the blocks imposed are sometimes more far-reaching than intended. In one incident, an attempt to block the cover image of the Scorpions album Virgin Killer hosted by Wikipedia (in itself a dubious decision) rendered the entire related article inaccessible as well as interfered with editing.

  Net neutrality

  Content filtering, or more precisely the lack thereof, is central to the concept of net neutrality. Usually discussed in the context of Internet service providers, this is the principle that the user should have equal, unfiltered access to all content. As a consequence, ISPs should not be held responsible for the content they deliver. Compare this to how the postal system works.

  The current debate shows that the principle of net neutrality is important not only at the ISP level, but should also include providers of essential services on the Internet. This means search engines should not be responsible for or be required to filter results, email hosts should not be required to scan users’ messages, and so on. No mandatory censoring can be effective without infringing the essential liberties of freedom of speech and press.

  Social networks operate in a less well-defined space. They are clearly not part of the essential Internet infrastructure, and they require that users sign up and agree to their terms and conditions. Because of this, they can include restrictions that would be unacceptable for the Internet as a whole. At the same time, social networks are growing in importance as means of communication between people, and as such they have a moral obligation to act fairly and apply their rules in a transparent manner.

  Facebook was recently under fire, accused of not taking sufficient measures to curb ‘hate speech,’ particularly against women. Eventually they pledged to review their policies and methods, and reducing the proliferation of such content will surely make the web a better place. Nevertheless, one must ask how Facebook (or another social network) might react to similar pressure from, say, a religious group demanding removal of ‘blasphemous’ content. What about demands from a foreign government ? Only yesterday, the Turkish prime minister Erdogan branded Twitter ‘a plague’ in a TV interview.

  Rather than impose upon Internet companies the burden of law enforcement, we should provide them the latitude to set their own policies as well as the legal confidence to stand firm in the face of unreasonable demands. The usual market forces will promote those acting responsibly.

  Further reading

  • Tory-Labour pact could save data bill, says Lord Howard
  • Internet companies warn May over ‘snooper’s charter’
  • Snooper’s charter ‘should be replaced by strengthening of existing powers’
  • Exclusive : ‘Snooper’s charter’ would not have prevented Woolwich attack, says MI5
  • Search engines urged to block more online porn sites
  • Why technology must be the solution to child abuse material online
  • Google must take more action to police explicit content, says Vince Cable
  • Facebook bows to campaign groups over ‘hate speech’
  • Facebook sexism campaign attracts thousands online
  • Türkischer Ministerpräsident : Twitter ist eine Plage
  • Valls : « La traque sur Internet doit être une priorité pour nous »
  • La Cnil, futur juge d’Internet
  • “National security matter” : Third agency caught unilaterally blocking web sites

• Unable to stream file onto localhost - ffmpeg

  18 octobre 2013, par trueblue

  I am new to ffmpeg/ffserver. I am trying to stream a local file named Trial onto a localhost using ffserver. I want to run the file in browser as http://localhost:8090/feed1.ffm
  I am executing the below command in Ubuntu(Trial is a Mpeg TS file) :

    ffmpeg -i Trial http://localhost:8090/feed1.ffm

  Upon execution of above command I am getting below error :

  FFmpeg version SVN-r0.5.9-4:0.5.9-0ubuntu0.10.04.3, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  
    configuration: --extra-version=4:0.5.9-0ubuntu0.10.04.3 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-vdpau --enable-bzlib --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --enable-zlib --disable-stripping --disable-vhook --enable-runtime-cpudetect --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --enable-libdc1394 --enable-shared --disable-static
  
    libavutil     49.15. 0 / 49.15. 0
  
    libavcodec    52.20. 1 / 52.20. 1
  
    libavformat   52.31. 0 / 52.31. 0
  
    libavdevice   52. 1. 0 / 52. 1. 0
  
    libavfilter    0. 4. 0 /  0. 4. 0
  
    libswscale     0. 7. 1 /  0. 7. 1
  
    libpostproc   51. 2. 0 / 51. 2. 0
  
    built on Jan 24 2013 19:42:59, gcc: 4.4.3
  
  
  
  Seems stream 0 codec frame rate differs from container frame rate: 119.88 (120000/1001) -> 59.94 (60000/1001)
  
  Input #0, mpegts, from 'Trial':
  
    Duration: 00:00:04.22, start: 0.177633, bitrate: 40368 kb/s
  
    Program 2 
  
      Stream #0.0[0x21]: Video: mpeg2video, yuv420p, 1280x720 [PAR 1:1 DAR 16:9], 45000 kb/s, 59.94 tbr, 90k tbn, 119.88 tbc
  
  Output #0, ffm, to 'http://localhost:8090/feed1.ffm':
  
      Stream #0.0: Video: flv, yuv420p, 352x288, q=1-5, 100 kb/s, 1000k tbn, 15 tbc
  
      Stream #0.1: Audio: mp2, 44100 Hz, mono, s16, 32 kb/s
  
      Stream #0.2: Video: mpeg1video, yuv420p, 160x128, q=3-31, 64 kb/s, 1000k tbn, 3 tbc
  
      Stream #0.3: Audio: mp2, 22050 Hz, mono, s16, 64 kb/s
  
      Stream #0.4: Video: msmpeg4, yuv420p, 352x240, q=3-31, 256 kb/s, 1000k tbn, 15 tbc
  
  Could not find input stream matching output stream #0.1

  My ffserver.conf file goes like this :

  # Port on which the server is listening. You must select a different
  
  # port from your standard HTTP web server if it is running on the same
  
  # computer.
  
  Port 8090
  
  
  
  # Address on which the server is bound. Only useful if you have
  
  # several network interfaces.
  
  BindAddress 0.0.0.0
  
  
  
  # Number of simultaneous HTTP connections that can be handled. It has
  
  # to be defined *before* the MaxClients parameter, since it defines the
  
  # MaxClients maximum limit.
  
  MaxHTTPConnections 2000
  
  
  
  # Number of simultaneous requests that can be handled. Since FFServer
  
  # is very fast, it is more likely that you will want to leave this high
  
  # and use MaxBandwidth, below.
  
  MaxClients 1000
  
  
  
  # This the maximum amount of kbit/sec that you are prepared to
  
  # consume when streaming to clients.
  
  MaxBandwidth 1000
  
  
  
  # Access log file (uses standard Apache log file format)
  
  # '-' is the standard output.
  
  CustomLog -
  
  
  
  # Suppress that if you want to launch ffserver as a daemon.
  
  NoDaemon
  
  
  
  
  
  ##################################################################
  
  # Definition of the live feeds. Each live feed contains one video
  
  # and/or audio sequence coming from an ffmpeg encoder or another
  
  # ffserver. This sequence may be encoded simultaneously with several
  
  # codecs at several resolutions.
  
  
  
  <feed>
  
  
  
  # You must use &#39;ffmpeg&#39; to send a live feed to ffserver. In this
  
  # example, you can type:
  
  #
  
  # ffmpeg http://localhost:8090/feed1.ffm
  
  
  
  # ffserver can also do time shifting. It means that it can stream any
  
  # previously recorded live stream. The request should contain:
  
  # "http://xxxx?date=[YYYY-MM-DDT][[HH:]MM:]SS[.m...]".You must specify
  
  # a path where the feed is stored on disk. You also specify the
  
  # maximum size of the feed, where zero means unlimited. Default:
  
  # File=/tmp/feed_name.ffm FileMaxSize=5M
  
  File /tmp/feed1.ffm
  
  FileMaxSize 5M
  
  
  
  # You could specify
  
  # ReadOnlyFile /saved/specialvideo.ffm
  
  # This marks the file as readonly and it will not be deleted or updated.
  
  
  
  # Specify launch in order to start ffmpeg automatically.
  
  # First ffmpeg must be defined with an appropriate path if needed,
  
  # after that options can follow, but avoid adding the http:// field
  
  #Launch ffmpeg
  
  
  
  # Only allow connections from localhost to the feed.
  
  ACL allow 127.0.0.1
  
  
  
  </feed>
  
  
  
  
  
  
  
  <stream>
  
  Feed feed1.ffm
  
  Format swf
  
  VideoCodec flv
  
  VideoFrameRate 15
  
  VideoBufferSize 80000
  
  VideoBitRate 100
  
  VideoQMin 1
  
  VideoQMax 5
  
  VideoSize 352x288
  
  PreRoll 0
  
  Noaudio
  
  </stream>
  
  
  
  ##################################################################
  
  # Now you can define each stream which will be generated from the
  
  # original audio and video stream. Each format has a filename (here
  
  # &#39;test1.mpg&#39;). FFServer will send this stream when answering a
  
  # request containing this filename.
  
  
  
  <stream>
  
  
  
  # coming from live feed &#39;feed1&#39;
  
  Feed feed1.ffm
  
  
  
  # Format of the stream : you can choose among:
  
  # mpeg       : MPEG-1 multiplexed video and audio
  
  # mpegvideo  : only MPEG-1 video
  
  # mp2        : MPEG-2 audio (use AudioCodec to select layer 2 and 3 codec)
  
  # ogg        : Ogg format (Vorbis audio codec)
  
  # rm         : RealNetworks-compatible stream. Multiplexed audio and video.
  
  # ra         : RealNetworks-compatible stream. Audio only.
  
  # mpjpeg     : Multipart JPEG (works with Netscape without any plugin)
  
  # jpeg       : Generate a single JPEG image.
  
  # asf        : ASF compatible streaming (Windows Media Player format).
  
  # swf        : Macromedia Flash compatible stream
  
  # avi        : AVI format (MPEG-4 video, MPEG audio sound)
  
  Format mpeg
  
  
  
  # Bitrate for the audio stream. Codecs usually support only a few
  
  # different bitrates.
  
  AudioBitRate 32
  
  
  
  # Number of audio channels: 1 = mono, 2 = stereo
  
  AudioChannels 1
  
  
  
  # Sampling frequency for audio. When using low bitrates, you should
  
  # lower this frequency to 22050 or 11025. The supported frequencies
  
  # depend on the selected audio codec.
  
  AudioSampleRate 44100
  
  
  
  # Bitrate for the video stream
  
  VideoBitRate 64
  
  
  
  
  
  # Ratecontrol buffer size
  
  VideoBufferSize 40
  
  
  
  # Number of frames per second
  
  VideoFrameRate 3
  
  
  
  # Size of the video frame: WxH (default: 160x128)
  
  # The following abbreviations are defined: sqcif, qcif, cif, 4cif, qqvga,
  
  # qvga, vga, svga, xga, uxga, qxga, sxga, qsxga, hsxga, wvga, wxga, wsxga,
  
  # wuxga, woxga, wqsxga, wquxga, whsxga, whuxga, cga, ega, hd480, hd720,
  
  # hd1080
  
  VideoSize 160x128
  
  
  
  # Transmit only intra frames (useful for low bitrates, but kills frame rate).
  
  #VideoIntraOnly
  
  
  
  # If non-intra only, an intra frame is transmitted every VideoGopSize
  
  # frames. Video synchronization can only begin at an intra frame.
  
  VideoGopSize 12
  
  
  
  # More MPEG-4 parameters
  
  # VideoHighQuality
  
  # Video4MotionVector
  
  
  
  # Choose your codecs:
  
  #AudioCodec mp2
  
  #VideoCodec mpeg1video
  
  
  
  # Suppress audio
  
  #NoAudio
  
  
  
  # Suppress video
  
  #NoVideo
  
  
  
  #VideoQMin 3
  
  #VideoQMax 31
  
  
  
  # Set this to the number of seconds backwards in time to start. Note that
  
  # most players will buffer 5-10 seconds of video, and also you need to allow
  
  # for a keyframe to appear in the data stream.
  
  #Preroll 15
  
  
  
  # ACL:
  
  
  
  # You can allow ranges of addresses (or single addresses)
  
  #ACL ALLOW <first address="address"> <last address="address">
  
  
  
  # You can deny ranges of addresses (or single addresses)
  
  #ACL DENY <first address="address"> <last address="address">
  
  
  
  # You can repeat the ACL allow/deny as often as you like. It is on a per
  
  # stream basis. The first match defines the action. If there are no matches,
  
  # then the default is the inverse of the last ACL statement.
  
  #
  
  # Thus &#39;ACL allow localhost&#39; only allows access from localhost.
  
  # &#39;ACL deny 1.0.0.0 1.255.255.255&#39; would deny the whole of network 1 and
  
  # allow everybody else.
  
  
  
  </last></first></last></first></stream>
  
  
  
  
  
  ##################################################################
  
  # Example streams
  
  
  
  
  
  # Multipart JPEG
  
  
  
  #<stream>
  
  #Feed feed1.ffm
  
  #Format mpjpeg
  
  #VideoFrameRate 2
  
  #VideoIntraOnly
  
  #NoAudio
  
  #Strict -1
  
  #</stream>
  
  
  
  
  
  # Single JPEG
  
  
  
  #<stream>
  
  #Feed feed1.ffm
  
  #Format jpeg
  
  #VideoFrameRate 2
  
  #VideoIntraOnly
  
  ##VideoSize 352x240
  
  #NoAudio
  
  #Strict -1
  
  #</stream>
  
  
  
  
  
  
  
  # Flash
  
  
  
  #<stream>
  
  #Feed feed1.ffm
  
  #Format swf
  
  #VideoFrameRate 2
  
  #VideoIntraOnly
  
  #NoAudio
  
  #</stream>
  
  
  
  
  
  # ASF compatible
  
  
  
  <stream>
  
  Feed feed1.ffm
  
  Format asf
  
  VideoFrameRate 15
  
  VideoSize 352x240
  
  VideoBitRate 256
  
  VideoBufferSize 40
  
  VideoGopSize 30
  
  AudioBitRate 64
  
  StartSendOnKey
  
  </stream>
  
  
  
  
  
  # MP3 audio
  
  
  
  #<stream>
  
  #Feed feed1.ffm
  
  #Format mp2
  
  #AudioCodec mp3
  
  #AudioBitRate 64
  
  #AudioChannels 1
  
  #AudioSampleRate 44100
  
  #NoVideo
  
  #</stream>
  
  
  
  
  
  # Ogg Vorbis audio
  
  
  
  #<stream>
  
  #Feed feed1.ffm
  
  #Title "Stream title"
  
  #AudioBitRate 64
  
  #AudioChannels 2
  
  #AudioSampleRate 44100
  
  #NoVideo
  
  #</stream>
  
  
  
  
  
  # Real with audio only at 32 kbits
  
  
  
  #<stream>
  
  #Feed feed1.ffm
  
  #Format rm
  
  #AudioBitRate 32
  
  #NoVideo
  
  #NoAudio
  
  #</stream>
  
  
  
  
  
  # Real with audio and video at 64 kbits
  
  
  
  #<stream>
  
  #Feed feed1.ffm
  
  #Format rm
  
  #AudioBitRate 32
  
  #VideoBitRate 128
  
  #VideoFrameRate 25
  
  #VideoGopSize 25
  
  #NoAudio
  
  #</stream>
  
  
  
  
  
  ##################################################################
  
  # A stream coming from a file: you only need to set the input
  
  # filename and optionally a new format. Supported conversions:
  
  #    AVI -> ASF
  
  
  
  #<stream>
  
  #File "/usr/local/httpd/htdocs/tlive.rm"
  
  #NoAudio
  
  #</stream>
  
  
  
  #<stream>
  
  #File "/usr/local/httpd/htdocs/test.asf"
  
  #NoAudio
  
  #Author "Me"
  
  #Copyright "Super MegaCorp"
  
  #Title "Test stream from disk"
  
  #Comment "Test comment"
  
  #</stream>
  
  
  
  
  
  ##################################################################
  
  # RTSP examples
  
  #
  
  # You can access this stream with the RTSP URL:
  
  #   rtsp://localhost:5454/test1-rtsp.mpg
  
  #
  
  # A non-standard RTSP redirector is also created. Its URL is:
  
  #   http://localhost:8090/test1-rtsp.rtsp
  
  
  
  #<stream>
  
  #Format rtp
  
  #File "/usr/local/httpd/htdocs/test1.mpg"
  
  #</stream>
  
  
  
  
  
  ##################################################################
  
  # SDP/multicast examples
  
  #
  
  # If you want to send your stream in multicast, you must set the
  
  # multicast address with MulticastAddress. The port and the TTL can
  
  # also be set.
  
  #
  
  # An SDP file is automatically generated by ffserver by adding the
  
  # &#39;sdp&#39; extension to the stream name (here
  
  # http://localhost:8090/test1-sdp.sdp). You should usually give this
  
  # file to your player to play the stream.
  
  #
  
  # The &#39;NoLoop&#39; option can be used to avoid looping when the stream is
  
  # terminated.
  
  
  
  #<stream>
  
  #Format rtp
  
  #File "/usr/local/httpd/htdocs/test1.mpg"
  
  #MulticastAddress 224.124.0.1
  
  #MulticastPort 5000
  
  #MulticastTTL 16
  
  #NoLoop
  
  #</stream>
  
  
  
  
  
  ##################################################################
  
  # Special streams
  
  
  
  # Server status
  
  
  
  <stream>
  
  Format status
  
  
  
  # Only allow local people to get the status
  
  ACL allow localhost
  
  ACL allow 192.168.0.0 192.168.255.255
  
  
  
  #FaviconURL http://pond1.gladstonefamily.net:8080/favicon.ico
  
  </stream>
  
  
  
  
  
  # Redirect index.html to the appropriate site
  
  
  
  <redirect>
  
  URL http://www.ffmpeg.org/
  
  </redirect>

  Kindly anyone please assist me whether I am missing something or do i need to change my server.conf file ? I have referred many websites. But still I am unable to fix it. Thanks in advance.

• Revision 67e41fe2f6 : vp9 com/dec : avoid reading unavailable above/left in most cases at least the le

  16 octobre 2013, par James Zern

  Changed Paths :
   Modify /vp9/common/vp9_pred_common.c

  
   Modify /vp9/common/vp9_pred_common.h

  
   Modify /vp9/decoder/vp9_decodemv.c

  
  
  vp9 com/dec : avoid reading unavailable above/left

  in most cases at least the left column was a harmless race as it was
  left unused later in the code.

  Change-Id : I43211df66fb157c6feecf08c681add4fcf18b644