Newest 'ffmpeg' Questions - Stack Overflow

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• Converting with ffmpeg a .mov to uncompressed .avi results in a black screen in virtualdub [migrated]

  28 mai 2013, par TazgerO

  I am trying to convert a .mov to an uncompressed .avi with ffmpeg. As I want no quality loss, I am using the following ffmpeg command:

  ffmpeg -i toto.mov -vcodec copy -y toto.avi
  

  The convertion works perfectly (the video works in VLC) except that when I am opening the file with virtualdub I get a black screen.

  In VirtualDub, under file information I get the following:

  Frame size: 800x600, 30.000fps
  Length: 802 frames
  Decompressor: Internal DIB decoder
  

  If I am not specifying the -pix_fmt and -vcodec arguments, ffmpeg convert to mpeg-4 and yuv420p but I am loosing on the quality as my file shrunk to about 400Mo to 1Mo but the video works in virtualdub and this time the Decompressor is set to ffdshow Video Codec (FMP4). I doubt this is a ffdshow as I had another video working perfectly with the internal DIB decoder.

  Any idea, to get the image in virtualdub?

• Identifying Audio bit rate using FFMPEG

  28 mai 2013, par user1756535

  I'm using FFMPEG to identify the bit rate of an audio file in my Rails app. I am downloading the file from S3, and storing temporarily in the tmp folder, then running FFMPEG commands against it.

  Locally everything is running absolutely as expected. The problem comes when deploying, and I get nothing returned from FFMPEG.

  s3 = AWS::S3.new(
  :access_key_id => ENV["AWS_ACCESS_KEY_ID"],
  :secret_access_key => ENV["AWS_SECRET_ACCESS_KEY"])
  
  object = s3.buckets[ENV["AWS_S3_BUCKET"]].objects[CGI::unescape(self.url)]
  
  tempname = Digest::MD5.hexdigest(DateTime.now.to_s) + "." + self.file_format
  File.open(Rails.root.to_s + '/tmp/' + tempname, 'wb') do |f|
      f.write(object.read)
  end
  
  dl = Rails.root.to_s + '/tmp/' + tempname
  brcommand = "ffmpeg -i " + dl + " 2>&1 | grep Duration | sed 's/Duration: \(.*\), start/\1/g'"
  ffmpeg = %x{#{brcommand}}
  

  I am using %x{ffmpeg_command} to access the command line, so I'm wandering whether that may be causing the problem where it is not finding the file as if it had been running natively in Rails.

  I have used FFMPEG on the command line on the server, so I know it is working fine.

• How to use existing .so file in my other android project in windows PC ?

  28 mai 2013, par Mihir Shah

  I have to use ffmpeg library for video editing application in android. I have no experience in JNI or NDK. but I have ffmpeg.so file. Can I directly use it in my new android application?

  I am using it but generating error: Caused by: java.lang.UnsatisfiedLinkError: Couldn't load videokit: findLibrary returned null

  If not, what are the steps to generate .so file? I have search lot of things but all are in mostly ubuntu. How to generate in windows or mac os? Can i decompile my existing .so file?

• Which filter should be used when i want to add watermark to a video ?

  28 mai 2013, par Blade Master

  Hi everyone,

  I want to add a watermark to a video use a picture. here is the problem

  and this is my command:

  c:\ffmpeg.exe -y -i c:\ffmpeg\input\walk.mp4 -acodec copy -b 300k -vf "movie=w1.jpg [watermark];[in][watermark] overlay=5:5 [out]" c:\ffmpeg\output\walk.mp4

  What am I doing wrong?

• FFmpeg : Generating .ts files and adding Metadata to them [closed]

  28 mai 2013, par Jonovono

  Before I was following the steps:

  1. Create some metadata:

     id3taggenerator -o 1.id3 -artist "Emma Stone"
     id3taggenerator -o 2.id3 -artist "Patricia Clarkson"
     

  2. Create a file saying where to place the metadata in the file:

     68 id3 /path/to/file/1.id3
     78 id3 /path/to/file/2.id3
     

  3. Segment the files and include the metadata

     mediafilesegmenter -f video -M meta.txt video.mp4
     

  More detail:

  http://jmacmullin.wordpress.com/2010/11/03/adding-meta-data-to-video-in-ios/

  I want to do something similar to this, but with FFmpeg.

  I am also wondering if I could first segment the file into .ts files and add metadata directly to those?

  I am having trouble finding the solution on the website. Any help or resources would be great. Thanks!