如何使用回形针加载和验证视频-Rails

Question

请帮忙解决问题

我用回形针整理上传图片。它有效。

现在我想组织一个视频上传。我改变了这个模型：型号：

class Video < ActiveRecord::Base
  validates :title, presence: true
  validates :video, presence: true

  belongs_to :user

  has_attached_file   :video, 
                      :styles => { :medium => "300x300>", :thumb => "100x100>" }, 
                      :default_url => "/images/:style/missing.png"

  validates_attachment_content_type :video, :content_type => /\Avideo\/.*\Z/  
  validates_attachment_file_name :video, :matches => [/3gp\Z/, /mp4\Z/, /flv\Z/]  

 validate :file_size_validation, :if => "video?"  

  def file_size_validation
    errors[:video] << "should be less than 2MB" if video.size.to_i > 30.megabytes
  end  
end

视频控制器：

def create
  @video = Video.new(video_params)   

  if @video.save
    @video.update_attributes(user: current_user)

    flash[:success] = :video_created
    redirect_to @video
  else
    flash.now[:error] = :user_not_created
    render 'new'
  end
end

形式：

<%= form_for(@video) do |f| %>
    <%= f.text_field  :title %>
    <%= f.file_field  :video %>
    <%= f.submit %>
<% end %>

尝试上传视频后，我在控制台收到以下错误消息：

Started POST "/videos" for 127.0.0.1 at 2015-07-23 14:17:32 +0300
Processing by VideosController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"RF3w8PzZ9LZ4pdqRPqRvHMQ+nYDL4om0YHAMlzTm8tf3iFmVmKxXSYKap3C0ogEnOkifm9i01oXs/rTX9zmtPA==", "video"=>{"title"=>"tty", "video"=>#<ActionDispatch::Http::UploadedFile:0x007f6624f10770 @tempfile=#<Tempfile:/tmp/RackMultipart20150723-13428-u7s8i8.flv>, @original_filename="mmm.flv", @content_type="video/x-flv", @headers="Content-Disposition: form-data; name=\"video[video]\"; filename=\"mmm.flv\"\r\nContent-Type: video/x-flv\r\n">}, "commit"=>"Create Video"}
  User Load (0.3ms)  SELECT  "users".* FROM "users" WHERE "users"."id" =   ORDER BY "users"."id" ASC LIMIT 1  [["id", 8]]
Command :: file -b --mime '/tmp/c4efd5020cb49b9d3257ffa0fbccc0ae20150723-13428-6gn39i.flv'
Command :: identify -format '%wx%h,%[exif:orientation]' '/tmp/c4efd5020cb49b9d3257ffa0fbccc0ae20150723-13428-1eailfd.flv[0]' 2>/dev/null
[paperclip] An error was received while processing: #<Paperclip::Errors::NotIdentifiedByImageMagickError: Paperclip::Errors::NotIdentifiedByImageMagickError>
Command :: identify -format '%wx%h,%[exif:orientation]' '/tmp/c4efd5020cb49b9d3257ffa0fbccc0ae20150723-13428-1eailfd.flv[0]' 2>/dev/null
[paperclip] An error was received while processing: #<Paperclip::Errors::NotIdentifiedByImageMagickError: Paperclip::Errors::NotIdentifiedByImageMagickError>
   (0.2ms)  BEGIN
Command :: file -b --mime '/tmp/c4efd5020cb49b9d3257ffa0fbccc0ae20150723-13428-khstwa.flv'
   (0.2ms)  ROLLBACK

屏幕上显示以下错误消息：

Video Paperclip::Errors::NotIdentifiedByImageMagickError

其中imageMagik安装在我的系统中：

sudo apt-get install imagemagick

db:

  create_table "videos", force: :cascade do |t|
    t.datetime "created_at",         null: false
    t.datetime "updated_at",         null: false
    t.string   "title"
    t.integer  "user_id"
    t.string   "video_file_size"
    t.string   "video_updated_at"
    t.string   "video_file_name"
    t.string   "video_content_type"
  end

Answer 1

paperclip的处理器是为图像设计的，所以它不能处理视频。您收到错误消息，指出 ImageMagick 未将此文件识别为图像。很公平，这不是图像！

不过，您可以自己编写一个 post 处理器，以及 paperclip's github page offers an example 调用自定义处理所需的语法 class:

has_attached_file :scan, :styles => { :text => { :quality => :better } },
                         :processors => [:ocr]

这定义了名为 text 的附件变体，它是通过使用（假设的）Paperclip::Ocr class 和选项散列 { :quality => :better }[ 处理上传的文件获得的=17=]

具体转换工具的选择由您决定，但您确实希望确保处理是异步完成的，而不是在通常的请求-响应周期内完成，您可能需要使用像 Sidekiq、Que 这样的后台队列或 Rails' (4.2+) ActiveJob。

Answer 2

使用 image 与 paperclip 和 video 是 different.Though 共同点是它会帮助您将上传的数据发送到服务器，但您需要用一些 processor.Just 来处理它，就像你对 images 使用 ImageMagick 一样，你应该使用 FFMPEG 到 encode/decode video。我将分享我通常用于视频的代码..但在此之前，您必须设置 ffmpeg 来处理所有格式的视频，就像您为 Imagemagick 所做的那样。 here 是为 ffmpeg 设置的，不要忘记使用 which ffmpeg

在环境文件中提供路径

您还需要 ffmpeg-paperclip 以及 coding/decoding 个视频。

video.rb
##using s3 
##convert the video into mp4 and also get screenshot of video at 5 sec
##add your own formats that you want 
has_attached_file :video,
  :styles => {
      :mp4video => { :geometry => '520x390', :format => 'mp4',
        :convert_options => { :output => { :vcodec => 'libx264',
          :vpre => 'ipod640', :b => '250k', :bt => '50k',
          :acodec => 'libfaac', :ab => '56k', :ac => 2 } } },
       :preview => { :geometry => '300x300>', :format => 'jpg', :time => 5 }
    },
    processors: [:ffmpeg],
    :storage => :s3,
    :size => { :in => 0..25.megabytes },
    :s3_permissions => :public_read,
    :s3_credentials => S3_CREDENTIALS

  validates_attachment_content_type :video, :content_type => /\Avideo\/.*\Z/
  validates_presence_of :video

保存视频后，您需要使用一些插件在 show 中显示视频播放器 action.You 可以使用 Mediaelement.js （我最喜欢的）。下载它，将它相应地转储到js/css文件中，将它包含在application.js和application.css中。

in your show.html.erb
##add video tag to show video

     <video autobuffer="autobuffer" preload="auto" style="width:100%;height:100%;" controls="controls" width="100%" height="100%" poster="<%= @video.video.url(:preview)%>" >
      <source  src="<%= @video.video.url%>"  />
     <%if @video.video.expiring_url(:mp4video).present? %>
     <source type="video/mp4"  src="<%= @video.video.url(:mp4video)%>" />
      <%end%>
     </video>

    ##javascript to handle video player
    $('video').mediaelementplayer();

如何使用回形针加载和验证视频-Rails

how to load and validate the video using paperclip-Rails

ruby-on-rails

ruby-on-rails-4

paperclip