Recherche avancée

Sur d’autres sites (4310)

• Graphics Magick output wrong colour when converting png to jpeg node js

  13 mai 2016, par Craig Wheatley

  Background is, I’m splitting a video (mp4, mov) into PNG frames using FFMPEG, then converting those to jpeg with GraphicsMagick.

  So I’m using GraphicsMagick in NodeJS, from here and below is a snippet :

  var gm = require('gm').subClass({imageMagick: true});
  
  
  
  gm('input.png')
  
  .write('output.jpg', (err) => {
  
    if (err) return console.log(err);
  
    console.log('done');
  
  });

  But the output jpeg colour is either washed out, or too dark.
  See here for the output. The original video is left (mov) and the converted JPEG’s are middle and right.
  The middle one, is the node app running on Heroku and the right image is the node app on my osx machine.

  I’ve read it could be to do with ’profiles’ but this doesn’t seem to make a difference :

  .profile('sRGB.icc')

  ’sRGB.icc’ is a colour profile I’ve downloaded.

  Any ideas ?

  I’ve also tried setting the colours amount to 16,777,216, tried setting the bit depth to 8 and 16, tried setting the colourspace to ’rgb’ to no avail.

• Load processed video instead of original video - Rails, Dragonfly

  1er février 2016, par Michael B

  In my Rails 4-Project, I am using Dragonfly to upload images and videos.
  For image-processing I use imagemagick, for videoprocessing I use ffmpeg.

  Videos are uploaded and stored in the folder uploads/videos. After processing, they are stored in public/ffmpeg_videos/

  My question is : How can I use the processed-video instead of the uploaded video ?

  e.g. I use this code in the view, to display a video :

  <video src="&lt;%=@video.video.url%>"></video>

  This successfully loads the original video from the upload-path. But what do I have to change, to load the video from the ffmpeg-path ?

  initializers/dragonfly.rb

  require 'dragonfly'
  
  
  
  # Configure
  
  Dragonfly.app(:images).configure do
  
    plugin :imagemagick
  
    protect_from_dos_attacks false
  
    secret 'd045734b043b4383a246c5c8daf2d3e31217dc8b030f21861e4fd16c4b72d382'
  
    url_format '/media/:job/:name'
  
  
  
    datastore :file,
  
              root_path: Rails.root.join('uploads/images/'),
  
              server_root: Rails.root.join('uploads')
  
  end
  
  
  
  Dragonfly.app(:videos).configure do
  
    secret 'd045734b043b4383a246c5c8daf2d3e31217dc8b030f21861e4fd16c4b72d382'
  
    url_format "/video/:job/:name"
  
  
  
    datastore :file,
  
              root_path: Rails.root.join('uploads/videos/'),
  
              server_root: Rails.root.join('uploads')
  
  end
  
  
  
  # Logger
  
  Dragonfly.logger = Rails.logger
  
  
  
  # Mount as middleware
  
  Rails.application.middleware.use Dragonfly::Middleware, :images
  
  Rails.application.middleware.use Dragonfly::Middleware, :videos
  
  
  
  # Add model functionality
  
  if defined?(ActiveRecord::Base)
  
    ActiveRecord::Base.extend Dragonfly::Model
  
    ActiveRecord::Base.extend Dragonfly::Model::Validations
  
  end

• iPhone video conversion to Android supported format using FFMPEG

  21 janvier 2016, par Muhammad Umar

  I have an iPhone video created as follow

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'vid.mp4':
  
    Metadata:
  
      major_brand     : qt  
  
      minor_version   : 0
  
      compatible_brands: qt  
  
      creation_time   : 2016-01-20 09:21:08
  
      make            : Apple
  
      make-eng        : Apple
  
      encoder         : 8.2
  
      encoder-eng     : 8.2
  
      date            : 2016-01-20T14:20:57+0500
  
      date-eng        : 2016-01-20T14:20:57+0500
  
      model           : iPhone 5
  
      model-eng       : iPhone 5
  
    Duration: 00:00:10.80, start: 0.000000, bitrate: 765 kb/s
  
      Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 62 kb/s (default)
  
      Metadata:
  
        creation_time   : 2016-01-20 09:21:08
  
        handler_name    : Core Media Data Handler
  
      Stream #0:1(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 320x320, 696 kb/s, 30 fps, 30 tbr, 600 tbn, 1200 tbc (default)
  
      Metadata:
  
        creation_time   : 2016-01-20 09:21:08
  
        handler_name    : Core Media Data Handler
  
        encoder         : H.264

  I want to convert it into Android support format so that all iPhone and maximum androids can read it.

  However if i convert to mpeg4 format using

  ffmpeg -i vid.mp4 -s 320x320 -vcodec mpeg4 -acodec aac -strict -2 -ac 2 -ar 44100 -ab 128k output.mp4

  it really degrades the quality

  How can i set the ffmpeg to create atleast as close as possible quality which runs on both android and iPhone