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Recently I edited an MPEG2 Video file that I had captured using AV Capture device on my Windows 7 Desktop. After edit, when I play back using Windows Media Player, there’s a sharp Click or Tick sound at the beginning and at the end of the clip. It was never there in the original file. I used Wondershare Video Editor.

Assuming it might be an issue with Media Player I tried VLC but it also plays that unwanted sound.

Assuming it might be a bug in Wondershare Video Editor, I tried WonderShare Filmora and then a few other free apps that just do cutting without any re-encoding. I am amazed that all of them introduce sharp 'Click' sound at the start and end of the new clip.

I am not much familiar with Video Editing. Is this normal or something is wrong somewhere and could there be any way to fix this?

Just a guess, but is there any way I can separate Audio & Video and mute that sharp Click in Audio part at the start & end and re-encode it in MPEG2 format?

In case relevant my Desktop config is AMD Athlon 3 Ghz CPU, 8 GB DDR3 RAM, Gigabyte 880 GM Board, 1 TB HDD & Windows 7 64 bit and in case the size of file matters it's hardly 30 MB, just about 1 minute of recording at 720 resolution.

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    What audio format did you use to capture? Signed / Unsigned? A loud pop or click like this can often be introduced by a DC offset that is incorrectly handled, either electrically or in the file or software. Try inspecting the beginning of the captured waveform in audacity to see if there is a sudden change in amplitude.
    – Attie
    Commented Jun 21, 2018 at 7:52
  • if it's not actually DC Offset which Audacity can fix then it may be that the cut was not at a zero-crossing; in which case you'd need to introduce a slight fade in & out at the edits.
    – Tetsujin
    Commented Jun 21, 2018 at 8:33

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Depending on the raw material, this click is likely to be an artefact of how image and audio data are combined (muxed) in the different formats. The fundamental underlying cause is, that while there is an image at different well-defined points in time (i.e. 25 times per second), the audio stream is continuous. If the audio stream inside the file now doesn't start exactly at a point in time, when the first image is to be displayed, artefacts appear.

The easiest way to fix this is to process audio and video seperately - just as professional editing software does. My recommendation is to use the command line tool ffmpeg, which is something like the swiss army knife of AV processing (and then some).

If you want to extract a part of a video, use

ffmpeg -ss [start time in seconds] -i [input file] -map '0:a' -vn -c copy -t [run time in seconds] [audio file.mka]
ffmpeg -ss [start time in seconds] -i [input file] -map '0:v' -an -c copy -t [run time in seconds] [video file.mkv]
ffmpeg -i [video file.mkv] -i [audio file.mka] -map '0:v' -map '1:a' -c copy [output file]

The first line extracts the audio segment, the second the video segment. The last line will combine ("multiplex" or "mux") those two files into a single result file.

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