Tag: editing

Add chapters to mp4

    1. Get the frame rate of your source video (assuming you have 30fps and the video is called input.mp4 for later steps)
    2. Calculate Timebase value
      => Timestamp fps*1000 => Timestamp 30000
      => Timebase 1/Timestamp => Timebase 1/30000
    3. Calculate all start and end timestamps using the following formula
      The timestamp 02:03:04.005 => 2 hours, 3 minutes, 4 seconds, 5 millisecond
      => timestamp = (hours*60^2 + minutes*60^1 + seconds*60^0 + millisecond*10^-3) * timebase
      => END Timestamp = Starting Timestamp of the following chapter – 1
      => Timestamp for this example: 221520150
      => And if this is the timestamp for chapter n, the end timestamp of chapter n-1 is: 221520149
    4. Use the following template to create a text file named meta.txt 
      ;FFMETADATA1
TITLE=ENTER_VIDEO_TITLE_HERE
PRODUCER=ENTER_PRODUCER_HERE
[CHAPTER]
TIMEBASE=1/30000
START=0
END=221520149
title=Chapter 01 - ENTER_TITLE_OF_CHAPTER_01
[CHAPTER]
TIMEBASE=1/30000
START=221520150
END=443020300
title=Chapter 02 - ENTER_TITLE_OF_CHAPTER_02
    5. Use ffmpeg to combine the metadata and source video: 
      ffmpeg -i input.mp4  -i meta.txt -c copy -map_metadata 1 output.mp4
    6. Open output.mp4 using vlc and verify that all timestamps are correct.