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• Precise method of segmenting & transcoding video+audio (via ffmpeg), into an on-demand HLS stream ?

  17 novembre 2019, par Felix

  recently I’ve been messing around with FFMPEG and streams through Nodejs. My ultimate goal is to serve a transcoded video stream - from any input filetype - via HTTP, generated in real-time as it’s needed in segments.

  I’m currently attempting to handle this using HLS. I pre-generate a dummy m3u8 manifest using the known duration of the input video. It contains a bunch of URLs that point to individual constant-duration segments. Then, once the client player starts requesting the individual URLs, I use the requested path to determine which time range of video the client needs. Then I transcode the video and stream that segment back to them.

  Now for the problem : This approach mostly works, but has a small audio bug. Currently, with most test input files, my code produces a video that - while playable - seems to have a very small (< .25 second) audio skip at the start of each segment.

  I think this may be an issue with splitting using time in ffmpeg, where possibly the audio stream cannot be accurately sliced at the exact frame the video is. So far, I’ve been unable to figure out a solution to this problem.

  If anybody has any direction they can steer me - or even a prexisting library/server that solves this use-case - I appreciate the guidance. My knowledge of video encoding is fairly limited.

  I’ll include an example of my relevant current code below, so others can see where I’m stuck. You should be able to run this as a Nodejs Express server, then point any HLS player at localhost:8080/master to load the manifest and begin playback. See the transcode.get('/segment/:seg.ts' line at the end, for the relevant transcoding bit.

  'use strict';
  
  const express = require('express');
  
  const ffmpeg = require('fluent-ffmpeg');
  
  let PORT = 8080;
  
  let HOST = 'localhost';
  
  const transcode = express();
  
  
  
  
  
  /*
  
   * This file demonstrates an Express-based server, which transcodes & streams a video file.
  
   * All transcoding is handled in memory, in chunks, as needed by the player.
  
   *
  
   * It works by generating a fake manifest file for an HLS stream, at the endpoint "/m3u8".
  
   * This manifest contains links to each "segment" video clip, which browser-side HLS players will load as-needed.
  
   *
  
   * The "/segment/:seg.ts" endpoint is the request destination for each clip,
  
   * and uses FFMpeg to generate each segment on-the-fly, based off which segment is requested.
  
   */
  
  
  
  
  
  const pathToMovie = 'C:\\input-file.mp4';  // The input file to stream as HLS.
  
  const segmentDur = 5; //  Controls the duration (in seconds) that the file will be chopped into.
  
  
  
  
  
  const getMetadata = async(file) => {
  
      return new Promise( resolve => {
  
          ffmpeg.ffprobe(file, function(err, metadata) {
  
              console.log(metadata);
  
              resolve(metadata);
  
          });
  
      });
  
  };
  
  
  
  
  
  
  
  // Generate a "master" m3u8 file, which the player should point to:
  
  transcode.get('/master', async(req, res) => {
  
      res.set({"Content-Disposition":"attachment; filename=\"m3u8.m3u8\""});
  
      res.send(`#EXTM3U
  
  #EXT-X-STREAM-INF:BANDWIDTH=150000
  
  /m3u8?num=1
  
  #EXT-X-STREAM-INF:BANDWIDTH=240000
  
  /m3u8?num=2`)
  
  });
  
  
  
  // Generate an m3u8 file to emulate a premade video manifest. Guesses segments based off duration.
  
  transcode.get('/m3u8', async(req, res) => {
  
      let met = await getMetadata(pathToMovie);
  
      let duration = met.format.duration;
  
  
  
      let out = '#EXTM3U\n' +
  
          '#EXT-X-VERSION:3\n' +
  
          `#EXT-X-TARGETDURATION:${segmentDur}\n` +
  
          '#EXT-X-MEDIA-SEQUENCE:0\n' +
  
          '#EXT-X-PLAYLIST-TYPE:VOD\n';
  
  
  
      let splits = Math.max(duration / segmentDur);
  
      for(let i=0; i< splits; i++){
  
          out += `#EXTINF:${segmentDur},\n/segment/${i}.ts\n`;
  
      }
  
      out+='#EXT-X-ENDLIST\n';
  
  
  
      res.set({"Content-Disposition":"attachment; filename=\"m3u8.m3u8\""});
  
      res.send(out);
  
  });
  
  
  
  // Transcode the input video file into segments, using the given segment number as time offset:
  
  transcode.get('/segment/:seg.ts', async(req, res) => {
  
      const segment = req.params.seg;
  
      const time = segment * segmentDur;
  
  
  
      let proc = new ffmpeg({source: pathToMovie})
  
          .seekInput(time)
  
          .duration(segmentDur)
  
          .outputOptions('-preset faster')
  
          .outputOptions('-g 50')
  
          .outputOptions('-profile:v main')
  
          .withAudioCodec('aac')
  
          .outputOptions('-ar 48000')
  
          .withAudioBitrate('155k')
  
          .withVideoBitrate('1000k')
  
          .outputOptions('-c:v h264')
  
          .outputOptions(`-output_ts_offset ${time}`)
  
          .format('mpegts')
  
          .on('error', function(err, st, ste) {
  
              console.log('an error happened:', err, st, ste);
  
          }).on('progress', function(progress) {
  
              console.log(progress);
  
          })
  
          .pipe(res, {end: true});
  
  });
  
  
  
  transcode.listen(PORT, HOST);
  
  console.log(`Running on http://${HOST}:${PORT}`);

• Vagrant provision fails to execute the next script without an obvious reason why

  14 juin 2016, par JakeTheSnake

  I’ve created/co-opted several bash scripts to provision my guest Ubuntu 14.04 OS ; the one giving me trouble right now is installing ffmpeg. When the script finishes, vagrant simply does nothing save for sending SSH keep-alives.

  Host OS : Windows 7 x64

  The last output before the infinitely repeating keep-alives is :

  INSTALL libavutil/sha.h
  
  INSTALL libavutil/sha512.h
  
  INSTALL libavutil/stereo3d.h
  
  INSTALL libavutil/threadmessage.h
  
  INSTALL libavutil/time.h
  
  INSTALL libavutil/timecode.h
  
  INSTALL libavutil/timestamp.h
  
  INSTALL libavutil/tree.h
  
  INSTALL libavutil/twofish.h
  
  INSTALL libavutil/version.h
  
  INSTALL libavutil/xtea.h
  
  INSTALL libavutil/tea.h
  
  INSTALL libavutil/lzo.h
  
  INSTALL libavutil/avconfig.h
  
  INSTALL libavutil/ffversion.h
  
  
  
  DEBUG ssh: stdout: INSTALL      libavutil/libavutil.pc
  
  
  
  DEBUG ssh: stdout: Done
  
  
  
  DEBUG ssh: Sending SSH keep-alive...
  
  DEBUG ssh: Sending SSH keep-alive...
  
  DEBUG ssh: Sending SSH keep-alive...

  Here are the relevant scripts :

  Vagrantfile

  # -*- mode: ruby -*-
  
  # vi: set ft=ruby :
  
  
  
  # All Vagrant configuration is done below. The "2" in Vagrant.configure
  
  # configures the configuration version (we support older styles for
  
  # backwards compatibility). Please don't change it unless you know what
  
  # you're doing.
  
  Vagrant.configure(2) do |config|
  
    # The most common configuration options are documented and commented below.
  
    # For a complete reference, please see the online documentation at
  
    # https://docs.vagrantup.com.
  
  
  
    # Every Vagrant development environment requires a box. You can search for
  
    # boxes at https://atlas.hashicorp.com/search.
  
    config.vm.box = 'ubuntu/trusty64'
  
    config.vm.hostname = 'dev'
  
  
  
    config.ssh.forward_agent = true
  
    config.ssh.pty = true
  
  
  
    # Create a private network, which allows host-only access to the machine
  
    # using a specific IP.
  
    config.vm.network :private_network, type: :dhcp, auto_config: false
  
  
  
    # Create a public network, which generally matched to bridged network.
  
    # Bridged networks make the machine appear as another physical device on
  
    # your network.
  
    config.vm.network :public_network,
  
                      ip: '192.168.11.14',
  
                      bridge: 'Realtek PCIe GBE Family Controller'
  
  
  
    # Share an additional folder to the guest VM. The first argument is
  
    # the path on the host to the actual folder. The second argument is
  
    # the path on the guest to mount the folder. And the optional third
  
    # argument is a set of non-required options.
  
    #
  
    # Do not share root directory of vagrant
  
    # config.vm.synced_folder '.', '/vagrant', disabled: true
  
    # Share ruby repository directories
  
    config.vm.synced_folder '.',
  
                            '/home/vagrant/apps',
  
                            nfs: true,
  
                            mount_options: [
  
                              'nfsvers=3',
  
                              'vers=3',
  
                              'actimeo=1',
  
                              'rsize=8192',
  
                              'wsize=8192',
  
                              'timeo=14',
  
                              :nolock,
  
                              :udp,
  
                              :intr,
  
                              :user,
  
                              :auto,
  
                              :exec,
  
                              :rw
  
                            ]
  
  
  
    # Provider-specific configuration so you can fine-tune various
  
    # backing providers for Vagrant. These expose provider-specific options.
  
    # Example for VirtualBox:
  
    #
  
    config.vm.provider :virtualbox do |vb|
  
      # Display the VirtualBox GUI when booting the machine
  
      vb.gui = true
  
  
  
      # Use VBoxManage to customize the VM.
  
      vb.name = 'Ubuntu'
  
      vb.cpus = 4
  
      vb.memory = 2048
  
      vb.customize ['modifyvm', :id, '--vram', 64]
  
      vb.customize ['modifyvm', :id, '--audio', :dsound]
  
      vb.customize ['modifyvm', :id, '--audiocontroller', :ac97]
  
      vb.customize ['modifyvm', :id, '--clipboard', :bidirectional]
  
    end
  
  
  
    # Provisioning
  
    config.vm.provision :shell, path: './provisioning/user/install-apps.sh',
  
                                privileged: false, name: 'Applications'
  
    config.vm.provision :shell, path: './provisioning/user/install-rvm.sh',
  
                                args: 'stable', privileged: false, name: 'RVM'
  
    config.vm.provision :shell, path: './provisioning/user/install-ruby.sh',
  
                                args: '2.3.1', privileged: false, name: 'Ruby'
  
    config.vm.provision :shell, path: './provisioning/user/install-ruby-gems.sh',
  
                                privileged: false, name: 'Ruby Gems'
  
    config.vm.provision :shell, path: './provisioning/root/install-nginx.sh',
  
                                args: '1.9.9', name: 'Nginx'
  
  
  
    config.vm.provision :chef_solo do |chef|
  
      # chef.version = '12.10.40'
  
  
  
      # Paths to your cookbooks (on the host)
  
      chef.cookbooks_path = ['cookbooks']
  
      # Add chef recipes
  
      chef.add_recipe 'apt'
  
      chef.add_recipe 'git' # Is required for NPM
  
      chef.add_recipe 'sqlite'
  
      chef.add_recipe 'mysql'
  
      chef.add_recipe 'nodejs'
  
      chef.add_recipe 'memcached'
  
      chef.add_recipe 'imagemagick'
  
      chef.add_recipe 'optipng'
  
      chef.add_recipe 'sublime-text'
  
      chef.add_recipe 'tomcat'
  
    end
  
  end

  install-apps.sh

  #!/usr/bin/env bash
  
  
  
  echo Turning off console beeps...
  
  grep '^set bell-style none' /etc/inputrc || echo 'set bell-style none' >> /etc/inputrc
  
  
  
  echo Installing languages
  
  sudo apt-get -y update
  
  sudo locale-gen en_US en_US.UTF-8
  
  sudo dpkg-reconfigure locales
  
  
  
  echo Installing essential apps
  
  sudo apt-get -y install build-essential curl yasm
  
  
  
  echo Installing desktop apps
  
  sudo apt-get -y install ubuntu-desktop
  
  
  
  hash ffmpeg 2>/dev/null || {
  
    # Build ffmpeg
  
    echo Installing ffmpeg
  
  
  
    sudo apt-get -y install autoconf automake libass-dev libfreetype6-dev \
  
      libsdl1.2-dev libtheora-dev libtool libva-dev libvdpau-dev libvorbis-dev libxcb1-dev libxcb-shm0-dev \
  
      libxcb-xfixes0-dev pkg-config texinfo zlib1g-dev libx264-dev libmp3lame-dev libopus-dev
  
  
  
    mkdir ~/ffmpeg_sources
  
    cd ~/ffmpeg_sources
  
    wget http://ffmpeg.org/releases/ffmpeg-snapshot.tar.bz2
  
    tar xjvf ffmpeg-snapshot.tar.bz2
  
    cd ffmpeg
  
    PATH="$HOME/bin:$PATH" PKG_CONFIG_PATH="$HOME/ffmpeg_build/lib/pkgconfig" ./configure \
  
      --prefix="$HOME/ffmpeg_build" \
  
      --pkg-config-flags="--static" \
  
      --extra-cflags="-I$HOME/ffmpeg_build/include" \
  
      --extra-ldflags="-L$HOME/ffmpeg_build/lib" \
  
      --bindir="$HOME/bin" \
  
      --enable-gpl \
  
      --enable-libass \
  
      --enable-libfreetype \
  
      --enable-libmp3lame \
  
      --enable-libopus \
  
      --enable-libtheora \
  
      --enable-libvorbis \
  
      --enable-libx264 \
  
      --enable-nonfree
  
  
  
    PATH="$HOME/bin:$PATH" make
  
    make install
  
    make distclean
  
    hash -r
  
  
  
    source ~/.profile
  
  }
  
  
  
  echo Done
  
  exit 0

  install-rvm.sh

  #!/usr/bin/env bash
  
  
  
  echo Installing RVM gpg key
  
  gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 --trust-model always
  
  
  
  echo Installing RVM
  
  \curl -sSL https://get.rvm.io | bash -s $1
  
  
  
  exit 0

  I won’t include the other scripts for the sake of brevity. When logging into vagrant with the gui nothing seems out of the ordinary, and ffmpeg is available...but nothing else is provisioned. No RVM, no Nginx, nothing.

• avfilter/avf_showcqt : cqt_calc optimization on x86

  4 juin 2016, par Muhammad Faiz

  avfilter/avf_showcqt : cqt_calc optimization on x86
  on x86_64 :
  
          time    PSNR
  
  plain   3.303   inf
  
  SSE     1.649   107.087535
  
  SSE3    1.632   107.087535
  
  AVX     1.409   106.986771
  
  FMA3    1.265   107.108437
  on x86_32 (PSNR compared to x86_64 plain) :
  
          time    PSNR
  
  plain   7.225   103.951979
  
  SSE     1.827   105.859282
  
  SSE3    1.819   105.859282
  
  AVX     1.533   105.997661
  
  FMA3    1.384   105.885377
  FMA4 test is not available
  Reviewed-by : James Almer <jamrial@gmail.com>
  
  Signed-off-by : Muhammad Faiz <mfcc64@gmail.com>
  

  • [DH] libavfilter/avf_showcqt.c
  • [DH] libavfilter/avf_showcqt.h
  • [DH] libavfilter/x86/Makefile
  • [DH] libavfilter/x86/avf_showcqt.asm
  • [DH] libavfilter/x86/avf_showcqt_init.c