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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

• Create silent wav and pipe it

  2 avril 2021, par Ícaro Erasmo

  I've been through many stackoverflow pages and forums trying to find the answer I want.
I created a virtual microphone and I'm trying to pipe to it some wav sounds created using FFMPEG.

  


  When I want to pipe a keyboard noise I pipe the sound to my virtual sound capture device like this :

  


  ffmpeg -fflags &#x2B;discardcorrupt -i <keyboard sound="sound" path="path"> -f s16le -ar 44100 -ac 1 - > /tmp/gapFakeMic&#xA;</keyboard>

  


  And when I want to pipe some synthetized voice sound using Espeak to my virtual microphone, I do this :

  


  espeak -vbrazil-mbrola-4 <some random="random" text="text"> --stdout | ffmpeg -fflags &#x2B;discardcorrupt -i pipe:0 -f s16le -ar 44100 -ac 1 - > /tmp/gapFakeMic&#xA;</some>

  


  The problem is my capture device doesn't record the sound like a normal recorder that still records even when there's no sound being transmited to it. So I'm trying to append the silence to the wav which is being created while my application is running. Always when I try to send the silence to buffer, FFMPEG returns the following response :

  


  [NULL @ 0x5579f7921a00] Unable to find a suitable output format for 'pipe:'


  


  FFMPEG is a powerful tool but its documentation lacks to be useful for newbies like me. So, I'd appreciate if anyone could answer this or at least give me any direction or some resource where I could find a way of achieving this.

  


  EDIT :

  


  Here's how I'm producing the silence to my virtual microphone :

  


  ffmpeg -f lavfi -i anullsrc=channel_layout=mono:sample_rate=44100 -t <time in="in" seconds="seconds"> - > /tmp/gapFakeMic&#xA;</time>

  


  Here's the full log :

  


  ffmpeg version 4.1.6-1~deb10u1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 8 (Debian 8.3.0-6)
  configuration: --prefix=/usr --extra-version='1~deb10u1' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared

  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100

Input #0, lavfi, from 'anullsrc=channel_layout=mono:sample_rate=44100':
  Duration: N/A, start: 0.000000, bitrate: 352 kb/s
    Stream #0:0: Audio: pcm_u8, 44100 Hz, mono, u8, 352 kb/s

[NULL @ 0x560516626f40] Unable to find a suitable output format for 'pipe:'
pipe:: Invalid argument


  


  EDIT 2 :

  


  After Gyan provided a solution in the comments the error above doesn't show anymore but my result audio is being broken and doesn't come out as expected. Now the command that generates and appends the silent audio is like this :

  


  ffmpeg -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=44100 -t <time in="in" seconds="seconds"> -f s16le - > /tmp/gapFakeMic&#xA;</time>

  


  Edit 3 :

  


  I've made some changes to the command I'm using to pipe silence to the virtual mic. I think the pipe is breaking because of some incompatibility in audio formats. I hope I can find a solution in the next few days. After every little change I realize some improvements. Now I can hear the silence between the keys sounds but it isn't recording all the audios I'm passing to it. Here's how the command is now :

  


  ffmpeg -f lavfi -i anullsrc=channel_layout=mono:sample_rate=44100 -t <time in="in" seconds="seconds"> -f s16le -ar 44100 -ac 1 - > /home/icaroerasmo/gapFakeMic`&#xA;</time>

  


  I also realized that when I pipe the sound to a pipe file created inside my home folder the audio quality improves.

  


  Edit 4 :

  


  After all this struggle it's clear now that the named pipe is breaking in the second time it's called. I've already googled how to flush a named pipe but I didn't find anything that worked.

  


• Apply filters to video while preview and save it with applied filter and original audio in android

  27 novembre 2019, par FreakInDroid

  I am new to video processing. I want to apply a filter to a video at runtime, and I want to save that video after filter applied.

  Regarding this I’m doing a research. I has gone through many libraries but I’m struggling to achieve my aim.

  Developement environment

  Migw-64 with windows 7 64 bit
  
  Android Studio 2.1 preview 5
  
  heap space 4GB 
  
  com.android.tools.build:gradle:2.1.0
  
  android-ndk-r12-win-x86_64
  
  com.android.tools.build:gradle-experimental:0.7.0  --> to build NDK

  I have tried

  1. AndroidFastImageprocessingLibrary

     Chrisbatt -> AndroidFastImageProcessing in github

     This library use GLSurfaceview to display filters but we could not save it to mp4 file.

     So I found another implementation of it icmobilelab -> AndroidFastImageProcessing in github

     This library use JavaCV with ffmpeg compiled. But it failed.

  2. JavaCV

     JavaCV use outdated ffmpeg and it is abandoned.

  3. Grafika -> on github

     I tried Android Fast Image Processing with RecordFBOActivity in grafika. But i have failed. This library use MediaRecorder to record the contents of GLSurfaceView. But it records video without audio (I have tested the RecordFBOActivity and analyze the code).

  4. filter packs in platform_frameworks

     github.com/android/platform_frameworks_base/blob/master/media/mca/filterpacks/java/android/filterpacks/videosink/MediaEncoderFilter.java
     its android 4.2 edited core. I can’t run this code because too many jni dependencies.

  5. ffmpeg

     github.com/guardianproject/android-ffmpeg
     I tried ffmpeg3.1 compilation procedure implemented by guardianproject. it successfullay built a static library but i cannot build dynamic library (so files). I’m stuck with a linker error. I think the linking order matters. I tried the linking order specified in below link
     https://fritzone.wordpress.com/2010/05/11/link-with-static-ffmpeg/
     but it won’t help. the following error occurs

     [armeabi-v7a] SharedLibrary  : libffmpeg.so
     
     jni/ffmpeg.c:200: error: undefined reference to 'av_frame_alloc'
     
     jni/ffmpeg.c:201: error: undefined reference to 'av_frame_alloc'
     
     jni/ffmpeg.c:209: error: undefined reference to 'av_register_all'
     
     jni/ffmpeg.c:210: error: undefined reference to 'avfilter_register_all'
     
     jni/ffmpeg.c:45: error: undefined reference to 'avformat_open_input'
     
     jni/ffmpeg.c:50: error: undefined reference to 'avformat_find_stream_info'
     
     jni/ffmpeg.c:56: error: undefined reference to 'av_find_best_stream'
     
     jni/ffmpeg.c:63: error: undefined reference to 'av_opt_set_int'
     
     jni/ffmpeg.c:66: error: undefined reference to 'avcodec_open2'
     
     jni/ffmpeg.c:67: error: undefined reference to 'av_log'
     
     jni/ffmpeg.c:78: error: undefined reference to 'avfilter_get_by_name'
     
     jni/ffmpeg.c:79: error: undefined reference to 'avfilter_get_by_name'
     
     jni/ffmpeg.c:80: error: undefined reference to 'avfilter_inout_alloc'
     
     jni/ffmpeg.c:81: error: undefined reference to 'avfilter_inout_alloc'
     
     jni/ffmpeg.c:85: error: undefined reference to 'avfilter_graph_alloc'
     
     jni/ffmpeg.c:98: error: undefined reference to 'avfilter_graph_create_filter'
     
     jni/ffmpeg.c:106: error: undefined reference to 'avfilter_graph_create_filter'
     
     jni/ffmpeg.c:113: error: undefined reference to 'av_int_list_length_for_size'
     
     jni/ffmpeg.c:113: error: undefined reference to 'av_opt_set_bin'
     
     jni/ffmpeg.c:116: error: undefined reference to 'av_log'
     
     jni/ffmpeg.c:131: error: undefined reference to 'av_strdup'
     
     jni/ffmpeg.c:142: error: undefined reference to 'av_strdup'
     
     jni/ffmpeg.c:147: error: undefined reference to 'avfilter_graph_parse_ptr'
     
     jni/ffmpeg.c:151: error: undefined reference to 'avfilter_graph_config'
     
     jni/ffmpeg.c:155: error: undefined reference to 'avfilter_inout_free'
     
     jni/ffmpeg.c:156: error: undefined reference to 'avfilter_inout_free'
     
     jni/ffmpeg.c:218: error: undefined reference to 'av_read_frame'
     
     jni/ffmpeg.c:223: error: undefined reference to 'avcodec_decode_video2'
     
     jni/ffmpeg.c:230: error: undefined reference to 'av_frame_get_best_effort_timestamp'
     
     jni/ffmpeg.c:233: error: undefined reference to 'av_buffersrc_add_frame_flags'
     
     jni/ffmpeg.c:234: error: undefined reference to 'av_log'
     
     jni/ffmpeg.c:240: error: undefined reference to 'av_buffersink_get_frame'
     
     jni/ffmpeg.c:171: error: undefined reference to 'av_rescale_q'
     
     jni/ffmpeg.c:246: error: undefined reference to 'av_frame_unref'
     
     jni/ffmpeg.c:248: error: undefined reference to 'av_frame_unref'
     
     jni/ffmpeg.c:251: error: undefined reference to 'av_packet_unref'
     
     jni/ffmpeg.c:254: error: undefined reference to 'avfilter_graph_free'
     
     jni/ffmpeg.c:255: error: undefined reference to 'avcodec_close'
     
     jni/ffmpeg.c:256: error: undefined reference to 'avformat_close_input'
     
     jni/ffmpeg.c:257: error: undefined reference to 'av_frame_free'
     
     jni/ffmpeg.c:258: error: undefined reference to 'av_frame_free'
     
     jni/include/libavutil/error.h:111: error: undefined reference to 'av_strerror'
     
     collect2.exe: error: ld returned 1 exit status
     
     make: *** [obj/local/armeabi/libffmpeg.so] Error 1

  6. MediaCodec, MediaExtractor,MediaRecord,MediaMuxer

     Finally I planned to combine AndroidFastImageProcessing with MediaCodec, MediaExtractor,MediaRecord,MediaMuxer.

     So I try to Extract audio from video using mediamuxer
     https://gist.github.com/sayan801/9a39ccad0818d2b3499a.
     I use mp4 video (MIME Type video/avc that have 2 tracks audio and video) to extract audio but the resultant file is corrupted (just 4 kb)

  I think this question is another view of the existing problem if anybody experienced this problem please guide me.