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• Lossless trim and crop of MJPEG video

  28 avril 2021, par prouast

  I am working on a project where I need to trim and crop MJPEG videos without any re-encoding. I have working code that accomplishes this by exporting the relevant frames as JPEGs, cropping them individually, and then joining them back together into an MJPEG.

  


  However, this seems quite inefficient and slow. I am looking for pointers how to improve this approach. For example, would it be possible to store the JPEGs in-memory ?

  


  import ffmpeg
import os
import shutil
import subprocess

def lossless_trim_and_crop(path, output_path, start, end, x, y, width, height, fps):
  # Trim the video in time and export all individual jpeg with ffmpeg + mjpeg2jpeg
  jpeg_folder = os.path.splitext(output_path)[0]
  jpeg_path = os.path.join(jpeg_folder, "frame_%03d.jpg")
  stream = ffmpeg.input(path, ss=start/fps, t=(end-start)/fps)
  stream = ffmpeg.output(stream, jpeg_path, vcodec='copy', **{'bsf:v': 'mjpeg2jpeg'})
  stream.run(quiet=True)
  # Crop all individual jpeg with jpegtran
  for filename in os.listdir(jpeg_folder):
    filepath = os.path.join(jpeg_folder, filename)
    out_filepath = os.path.splitext(filepath)[0] + "_c.jpg"
    subprocess.call(
      "jpegtran -perfect -crop {}x{}+{}+{} -outfile {} {}".format(
        width, height, x, y, out_filepath, filepath), shell=True)
    os.remove(filepath)
  # Join individual jpg back together
  cropped_jpeg_path = os.path.join(jpeg_folder, "frame_%03d_c.jpg")
  stream = ffmpeg.input(cropped_jpeg_path, framerate=fps)
  stream = ffmpeg.output(stream, output_path, vcodec='copy')
  stream.run(quiet=True)
  # Delete jpeg directory
  shutil.rmtree(jpeg_folder)


  


• AE per frame rendering FFMPEG forming to video

  9 février 2018, par Deckard Cain

  I’m trying to setup an automated per frame rendering system using After Effects and FFMPEG. The idea here is that my slave nodes (running AE), will generate the frames and save them immediately to a Samba share (this way I can team multiple slaves together to tackle the same project file and we aren’t writing an 8GB AVI file, then compressing and deleting it when we could just render 300MB of frames and form it).

  The database and Samba share are running on FreeBSD. This machine will then take those frames and use FFMPEG to combine them into an MP4 video.

  The issue that I’m running into, is that when I render out the After Effects project file directly to an AVI file (one slave, no individual frame rendering), the video length is 1:31. When I render out the exact same project file into individual frames, then run it through FFMPEG to combine and compress them, the output is 1:49.

  I have tried a billion different things to make the length of the video the same, but can’t seem to make it so :/

  aerender.exe -mp -project %PROJECTFILE% -comp %COMPOSITION% -output [########].jpg

  ^Keep in mind, there may be 99999999 frames, or as little as 1 that needs to be rendered (if we need to re-render a specific section because of an asset change)

  ffmpeg -nostdin -i %FRAMELOCATION% -c:v libx264 -preset veryfast -an -y outputVideo.mp4

• "File doesn't exist" - streamio FFMPEG on screenshot after create method

  3 mai 2013, par dodgerogers747

  I have videos being directly uploaded to S3 using Amazon's CORS configuration. Videos are uploaded via a dedicated S3 form, once they have been uploaded successfully the URL of the video is appended to the @video.file hidden_field via javascript and then the video saves.

  I can't get this after_save method to work which takes a screenshot of the video and saves it to S3 via carrierwave after the video has been saved as a rails object. ( It was previously working using a carrierwave video upload instance )

  It errors out withErrno::ENOENT - No such file or directory - the file 'http://bucket-name.s3.amazonaws.com/uploads/video/file/secure-random-hex/video_name.m4v' does not exist: I have tried running this method as a class method to call it from the console but it always comes back with the same error, even though the video exists.

  My bucket is set to public, read and write. How come it doesn't think the file exists ?

  If anyone needs more code just shout, thanks in advance.

  application trace

  Started POST "/videos" for 127.0.0.1 at 2013-05-03 10:48:07 -0700
  
  Processing by VideosController#create as JS
  
    Parameters: {"utf8"=>"✓", "authenticity_token"=>"MAHxrVcmPDtVIMfDWZBwL0YnzaAaAe1PTGip5M4OVoY=", "video"=>{"user_id"=>"5", "file"=>"http://bucket-name.s3.amazonaws.com/uploads/video/file/secure-random-hex/video.m4v"}}
  
    User Load (0.3ms)  SELECT `users`.* FROM `users` WHERE `users`.`id` = 5 LIMIT 1
  
     (0.1ms)  BEGIN
  
    SQL (20.5ms)  INSERT INTO `videos` (`created_at`, `file`, `question_id`, `screenshot`, `updated_at`, `user_id`) VALUES ('2013-05-03 17:48:07', 'http://teebox-network.s3.amazonaws.com/uploads/video/file/secure-random-hex/video.m4v', NULL, NULL, '2013-05-03 17:48:07', 5)
  
     (44.0ms)  ROLLBACK
  
  Completed 500 Internal Server Error in 71ms
  
  
  
  Errno::ENOENT - No such file or directory - the file 'http://teebox-network.s3.amazonaws.com/uploads/video/file/secure-random-hex/video.m4v' does not exist:
  
    (gem) streamio-ffmpeg-0.9.0/lib/ffmpeg/movie.rb:10:in `initialize'
  
    app/models/video.rb:25:in `new'
  
    app/models/video.rb:25:in `take_screenshot'

  video.rb

    attr_accessible :user_id, :question_id, :file, :screenshot
  
    belongs_to :question
  
    belongs_to :user
  
  
  
    default_scope order('created_at DESC')
  
  
  
    after_create :take_screenshot
  
  
  
    mount_uploader :screenshot, ImageUploader
  
  
  
    validates_presence_of :user_id, :file
  
  
  
    def take_screenshot
  
      FFMPEG.ffmpeg_binary = '/opt/local/bin/ffmpeg'
  
      movie = FFMPEG::Movie.new("#{self.file}")
  
      self.screenshot = movie.screenshot("#{Rails.root}/public/uploads/tmp/screenshots/#{File.basename(self.file)}.jpg", seek_time: 2 )
  
      self.save!
  
    end

  videos/_form.html.erb

  <form action="http://bucket-name.s3.amazonaws.com" data-remote="true" class="direct-upload" enctype="multipart/form-data" method="post">
  
    <input type="hidden" />
  
    <input type="hidden" value="ACCESS_KEY" />
  
    <input type="hidden" value="public-read" />
  
    <input type="hidden" />
  
    <input type="hidden" />
  
    <input type="hidden" value="201" />
  
    <input type="file" />
  
  </form>
  
  
  
  &lt;%= form_for @video, html: { multipart: true, id: "new_video" }, remote: true do |f| %>
  
          &lt;% if @video.errors.any? %>
  
      <div>
  
      <h2>&lt;%= pluralize(@video.errors.count, "error") %> prohibited this post from being saved:</h2>
  
  
  
    <ul>
  
      &lt;% @video.errors.full_messages.each do |msg| %>
  
          <li>&lt;%= msg %></li>
  
          &lt;% end %>
  
      </ul>
  
      </div>
  
  &lt;% end %>
  
  
  
      &lt;%= f.hidden_field :user_id, value: current_user.id %>
  
      &lt;%= f.hidden_field :file %><br />
  
  
  
      &lt;% end %>

  ImageUploader

  class ImageUploader < CarrierWave::Uploader::Base
  
  
  
    include CarrierWave::RMagick
  
  
  
     include Sprockets::Helpers::RailsHelper
  
     include Sprockets::Helpers::IsolatedHelper
  
  
  
    storage :fog
  
  
  
    before :store, :remember_cache_id
  
    after :store, :delete_tmp_dir
  
  
  
      def cache_dir
  
        Rails.root.join('public/uploads/tmp/') 
  
      end
  
  
  
      def remember_cache_id(new_file)
  
        @cache_id_was = cache_id
  
      end
  
  
  
      def delete_tmp_dir(new_file)
  
        if @cache_id_was.present? && @cache_id_was =~ /\A[\d]{8}\-[\d]{4}\-[\d]+\-[\d]{4}\z/
  
          FileUtils.rm_rf(File.join(root, cache_dir, @cache_id_was))
  
        end
  
      end
  
  
  
    process resize_and_pad: [306, 150, '#000']
  
  
  
    def store_dir
  
      "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  
    end
  
  
  
    def extension_white_list
  
      %w(jpg)
  
      # %w(ogg ogv 3gp mp4 m4v webm mov)
  
    end