Recherche avancée

Sur d’autres sites (7252)

• Révision 21956 : report de z88102

  20 mars 2015, par erational@erational.org

  autoriser la lecture des css pour l’évalution du site en "mobile friendly"
  https://www.google.com/webmasters/tools/mobile-friendly/

• Compress / Reduce file size of VIDEO

  2 avril 2014, par rishiJasapara

  I currently have a system in place where the user can upload a MP4 file and the same is available for download on mobile devices. But sometimes, the videos are more than 5MB in size and back here in my country, majority of the population uses 2G. So it typically takes 15-20 minutes to download large videos.

  Is there any way in which I can compress MP4 files while they are being uploaded and then save them in the folder so that instead of a 5MB video, I get a 2MB video which takes relatively less time to download. File format will always be MP4 only.

  I know of FFMPEG-PHP, but as far as I read, it only supports extracting information of the video and for video conversion. I could not find any reference for VIDEO COMPRESSION. I would be grateful if you could guide me on this.

• ffmpeg conditional rotation of video

  8 octobre 2014, par scientiffic

  I’m having issues uploading portrait videos using the Carrierwave-Video gem. When portrait videos are uploaded (particularly video captured on mobile devices), they are rotated 90 degrees clockwise. In the Carrierwave-Video documentation, there’s an option for dynamic configuration, but I don’t see a way to dynamically pass custom parameters for transcoding the video based on video orientation. I know that if I run the following line, I’m able to rotate the video 90 degrees CCW :

  encode_video(:mp4, custom: "-vf transpose=1")

  but I need a reliable way to detect whether the video needs to be rotated or not. I was wondering if there was some way for me to run a conditional parameter with ffmpeg that only runs if the video is portrait.

  In case it’s helpful, this is what my Video Uploader looks like in my Rails app (for some reason, the transcoding process is being run even before it detects the orientation of the video) :

  require 'carrierwave/processing/mime_types'
  
  
  
  class VideoPathUploader < CarrierWave::Uploader::Base
  
  
  
    include CarrierWave::Video
  
    include CarrierWave::Video::Thumbnailer
  
    include CarrierWave::MimeTypes
  
  
  
   process :encode
  
  
  
  def encode
  
      Rails.logger.debug "in encode"
  
      video = FFMPEG::Movie.new(@file.path)
  
      video_width = video.width
  
      video_height = video.height
  
      Rails.logger.debug "video widthxheight: #{video.width}x#{video.height}"
  
      aspect_ratio = video_width/video_height
  
      if video_height > video_width
  
        # rotate video
  
        Rails.logger.debug "portrait video"
  
        encode_video(:mp4, custom: "-vf transpose=1", aspect: aspect_ratio)
  
      else
  
        encode_video(:mp4, aspect: aspect_ratio)
  
      end
  
  
  
      instance_variable_set(:@content_type, "video/mp4")
  
      :set_content_type_mp4
  
    end
  
  end