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• как сделать 8 d музыку -> ffmpeg [closed]

  3 janvier 2023, par имя фамилия

  Всех приветствую, подскажите как через ffmpeg создать трек 8D
8D музыка это - метод постобработки аудиозаписи, когда диджеи берут уже существующий трек и микшируют его, создавая эффект движения звука вокруг слушателя.
По сути, 8D-аудио эмулирует звучание surround-формата Ambisonics. Последний подразумевает, что слушатель находится в центре «акустической сферы», по краям которой расставлены источники звука. (на одном форуме спросил что такое 8D)

  


  Писал на форуме, там не знаю решения, пробовал найти в открытых источниках, но видимо таким вопросом не задавались

  


• Using batch, how would you iterate through an array that you don't know how many values it may contain to run a function on each individual variable

  10 mai 2017, par Jay1995

  I have a batch file creating an array of variables it gets from a textfile, as follows :

  for /f "skip=1 tokens=9 delims= " %%a in (%findfile%) do set "_%%a=yes"
  
  set count = 0
  
  for /f "tokens=1* delims==#" %%b in ('set _') do (
  
      set /a count+=1
  
      set x=%%b
  
      set location[!count!]=!x:~1!
  
  )
  
  set %location%

  I’m trying to get each variable from the array to be looped into a function individually, but have no idea how to do it !!

  The location array storing all the variables has to be called into a for loop and the function I’m trying to get it to loop into is an FFMPEG function :

  for %%i in (%location%\*.mp4) do (if not exist "%%~ni\" MD "%%~ni"
  
  
  
      ffmpeg -i "%%i" -vframes 1 -f image2 -start_number 0 
  
      "%%~ni\%%~ni_Summary_%%3d.jpeg"
  
  
  
  )

  All HELP would be greatly appreciated

• 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