ruby-on-rails - Errno::ENOENT:从 S3 中查找视频持续时间时没有此类文件或目录

Question

在rails中使用gem paperclip-ffmpeg进行视频。它工作正常，但是当我发现视频的持续时间以秒为单位时，它给了我一个错误

Errno::ENOENT: No such file or directory - the file 'http://getpayad-dev.s3.amazonaws.com/ads/videos/000/000/014/original/Ufone_Tarzan_commercial_%28Ufone_Network_Quality%29_most_Funny_Ad.mp4?1451555000' does not exist
from /home/des0071/.rvm/gems/ruby-2.2.1/gems/streamio-ffmpeg-1.0.0/lib/ffmpeg/movie.rb:11:in `initialize

我的代码是

movie  = FFMPEG::Movie.new("#{self.video.url}")

Answer 1

好吧，这里可以找到 FFMPEG::Movie.new 定义:streamio-ffmpeg/movie.rb

raise Errno::ENOENT, "the file '#{path}' does not exist" unless File.exists?(path)

#ruby 2.2.0p0 (2014-12-25 revision 49005)
File.exists?("http://getpayad-dev.s3.amazonaws.com/ads/videos/000/000/014/original/Ufone_Tarzan_commercial_%28Ufone_Network_Quality%29_most_Funny_Ad.mp4?1451555000")
=> false

问题出在 ruby​​ 的文件类上。所以我尝试了这个:

   File.exists?("http://www.google.com")
   => false

好的，所以要么 google 不在线，要么 File 不能将 URI 作为参数。

A File is an abstraction of any file object accessible by the program and is closely associated with class IO File includes the methods of module FileTest as class methods, allowing you to write (for example) File.exist?("foo"). Class: File Ruby 2.2.0

那么，File Class 真的是 IO 的子类，IO 是怎么说的呢？

Many of the examples in this section use the File class, the only standard subclass of IO. The two classes are closely associated. Like the File class, the Socket library subclasses from IO (such as TCPSocket or UDPSocket). Class:IO Ruby 2.2.0

看起来错误的原因是由于继承，或者因为 gem 不是为了通过 http 流式传输文件而设计的。