I used the silencedetect of ffmpeg with noise value of -30dB to get the silent parts of a small video file & used those timestamps to trim & re-encode the silent parts of the videos.

I had used the audio peak meter in Shotcut(a video editor software) to see that anything below -30dB can be considered as silence.

When I opened re-encoded output video file in Shotcut, I saw that there were still some sections of video that were below -30dB & longer than the silence duration value I had passed into the ffmpeg command.

On closer inspection, I realized that the audio peak meter shown in Shotcut measures in dBFS & the noise value I entered in ffmpeg is in dB.

My knowledge of audio signal is very basic & hence I looked up what's dBFS. I understood that dBFS stands for dB Full Scale & is somehow related to the maximum possible volume in a WAV format.

My question is, how to pass the value in dBFS to ffmpeg instead of in dB? I checked the ffmpeg documentation & it does not say that we can pass values in dBFS.

  • dBFS is same as dB, make sure that shotcut is displaying correct info and also that your app that trims stuff is actually correct.
    – user12174
    Feb 19, 2021 at 17:20
  • @PaulB.Mahol Nope, you're wrong. Check also here where OP already asked the same question: sound.stackexchange.com/questions/50418/…
    – Matt
    Feb 19, 2021 at 18:17
  • I'm not wrong, It is easy to post false information today.
    – user12174
    Feb 19, 2021 at 19:03
  • @PaulB.Mahol there's no app, I just used the timestamps derived from silencedetect filter into a second ffmpeg command that did the trimming. So, there isn't much chance for error other than manual data entry errors. I checked there weren't any of those errors.
    – icyGuy
    Feb 22, 2021 at 12:53


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