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What should we do after we dub the audio?

Do the following to submit an .ogv video with a good video quality and less file size

Step 1

  1. We recommend that you dub/record using Audacity
    (it is available for all OS : Linux Distributions, Windows [all versions] and also for Mac OSX)
  2. After you record in Audacity -
    • Click on File -> Export -> save as *.mp3
    • This will export the final audio as an "*.mp3" file
  3. If you are using Movie Maker -
    • Convert the output file as an "*.mp3" using Any Video Convertor (Free Version)

Step 2

  1. After that download the original ".mov" English video from this link For dubbers outside IIT Bombay / For dubbers inside IIT Bombay
  2. Place the dubbed audio file (.mp3 format) and the downloaded English video file (.mov format) in the same folder.
    (Please Note that, you have to use FFmpeg Command Line for the following process
    So ensure that it is installed on your machine.)
  3. Do the following in a Linux machine -
    • Open the Terminal and go to the folder using cd command
    For e.g. cd Desktop/linux
  4. Here linux is the folder in which I have saved the audio and video files for conversion
    In my case, the file names are :
    1. English Video : linux-basic-of-syatem-admin-english.mov
    2. Dubbed Audio  : linux-basic-of-syatem-admin-tamil-dubbed.mp3

Step 3

  1. First : Remove the English audio from the downloaded English mov video
    Type the command :
    ffmpeg -i linux-basic-of-syatem-admin-english.mov -an -vcodec copy linux-basic-of-system-admin-english-video-without-audio.mov
    This command will remove the audio from the input video (linux-basic-of-syatem-admin-english.mov) and
    save the output video (linux-basic-of-system-admin-english-video-without-audio.mov) in mov format itself
  2. Second : Merge the dubbed audio with the English video without audio
    Type the command :
    ffmpeg -i linux-basic-of-system-admin-english-video-without-audio.mov -i linux-basic-of-syatem-admin-tamil-dubbed.mp3 -vcodec copy -acodec copy linux-basic-of-system-admin-tamil.mov
    This command will merge the dubbed audio (in .mp3 format) with the English video with out audio (in .mov format) and
    save the output in .mov format (linux-basic-of-system-admin-tamil.mov)

Step 4

  1. Convert the dubbed mov file into ogv video
    1. We have the dubbed video in .mov format with the same quality like the original English video
    2. But we need it in .ogv format.
    3. To convert mov into an ogv video, use a Firefox add-on called Firefogg
    4. We have to use the latest version of Firefox Web browser (Firefox version 5 and above)
    5. Click on this link Firefogg to add this add-on into our Firefox Web browser
    6. Follow the steps shown and install Firefogg
  2. Now, we can convert our videos into ogv videos
    1. Open Firefox
    2. Click on Tools -> Make Web Video
    3. This will open the firefogg conversion process in a new tab
    4. Click on the Select File option
    5. Browse the File
    6. After selection the file, it direct to file format/preset page. Click on Advance Options
    7. In the advance settings page,
      • Change the Format as Ogg(Theora/Vorbis)
      • Set Audio Quality as 5


    1. Click on Encode
    2. It will prompt you for the location to save the output video
    3. So, choose the location where you want to save
    4. Also confirm that it is saving in ogv format and click on Save
    5. The conversion process will take some time
    6. After the conversion is over, it will show the preview of the converted ogv video

  So finally we will get the dubbed video in OGV format in GOOD QUALITY with LESSER FILE SIZE
  Note that, the video filename should be submitted with proper Naming Convention as shown below :
  foss-name-level-topic-name-language.ogv (linux-basic-basics-of-syatem-admin-tamil.ogv)

Contributors and Content Editors

Nancy varkey, Pravin1389, St-admin