<p>I used the silencedetect of ffmpeg with noise value of <strong>-30dB</strong> to get the silent parts of a small video file &amp; used those timestamps to trim &amp; re-encode the silent parts of the videos.</p>
<p>I had used the audio peak meter in Shotcut(a video editor software) to see that anything below <strong>-30dB</strong> can be considered as silence.</p>
<p>When I opened re-encoded output video file in Shotcut, I saw that there were still some sections of video that were below -30dB &amp; longer than the silence duration value I had passed into the ffmpeg command.</p>
<p>On closer inspection, I realized that the audio peak meter shown in Shotcut measures in <strong>dBFS</strong> &amp; the noise value I entered in ffmpeg is in <strong>dB</strong>.</p>
<p>My knowledge of audio signal is very basic &amp; hence I looked up what's <strong>dBFS</strong>. I understood that <strong>dBFS</strong> stands for dB Full Scale &amp; is somehow related to the maximum possible volume in a <strong>WAV</strong> format.</p>
<p>My question is, how to pass the value in <strong>dBFS</strong> to ffmpeg instead of in <strong>dB</strong>?
I checked the ffmpeg documentation &amp; it does not say that we can pass values in <strong>dBFS</strong>.</p>

CC BY-SA 4.0
2021-02-19T18:17:36.800Z
@PaulB.Mahol Nope, you're wrong. Check also here where OP already asked the same question: https://sound.stackexchange.com/questions/50418/how-to-input-noise-values-in-dbfs-for-ffmpeg-silence-detect
Matt
CC BY-SA 4.0
2021-02-22T12:53:18.117Z
@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
<ffmpeg><audio><noise>
How to input noise values in dBFS for ffmpeg silence detect
icyGuy
# How to input noise values in dBFS for ffmpeg silence detect

(Asked by: username_0 on 2021-02-16)

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**.

**Tags:** ffmpeg, audio, noise

> **Comments:**
> **username_1**: @PaulB.Mahol Nope, you're wrong. Check also here where OP already asked the same question: https://sound.stackexchange.com/questions/50418/how-to-input-noise-values-in-dbfs-for-ffmpeg-silence-detect  
> **username_0**: @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.  

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## 0 answers

