---
name: "qwavfade"
section: "1"
platform: "linux"
package: "quelcom"
version: "0.4.0-16"
release: "Debian 12 (Bookworm)"
platforms: ["linux"]
url: "https://new.carta.tech/qwavfade"
---

# qwavfade(1)

fade in/out wav files

## NAME

qwavfade - fade in/out wav files

## SYNOPSIS

**qwavfade** \[*option*\]... *file*...

## DESCRIPTION

**qwavfade** modifies a wav file applying on it a fade in or a fade out or both.

a fade consists in modifying progressively the level of the wav as if you were slowly increasing or decreasing the volume. a fade in consists in increasing the volume starting from a low level at the beginning of the wav. a fade out consists in decreasing the volume to a low level at the end of the wav.

## OPTIONS

- **-d** \<*duration*\>\[\<*format*\>\], **--duration**=\<*duration*\>\[\<*format*\>\]

  *duration* is a positive integer that specifies the duration of the fade. the value is treated as a sample number unless a format specifier is used. see the **FORMATS** section below for information. the default value is five seconds. this option overrides the *--length* option explained below.

- **-h**, **--help**

  show a brief help and exit.

- **-i**, **--in**

  just fade in. don't fade out. by default, fade in and fade out.

- **-l** \<*time point*\>, **--length**=\<*time point*\>

  *time point* specifies the length(=duration) of the fade. see the **TIME POINTS** section below for information. this option is quite similar to the *--duration* option above. its easier to use though not as powerful than the previous one. the default value is five seconds. this option overrides the *--duration* option explained above.

- **-o**, **--out**

  just fade out. don't fade in. by default, fade in and fade out.

- **-t**, **--test**

  this option can be used to create and fade a tests files instead of modifying to original file. a test file will be created for each type of selected fade (in or out). the name of the test file will be **fadein.**\<*file*\> or **fadeout.**\<*file*. the duration of the test files is the fade duration plus two seconds.

- **-v**, **--verbose**

  show more detailed info.

- **-V**, **--version**

  show version and exit.

## TIME POINTS

the time points is a easier way to specify the length (or duration) of a fade with a millisecond resolution. here's its formal form:

\[*h***:**\[*m***:**\]\]**s**\[**.***ms*\] where

- **h**

  value is a positive integer meaning hours.

- **m**

  value is a positive integer meaning minutes.

- **s**

  value is a positive integer meaning seconds.

- **ms**

  value is a positive integer meaning milliseconds.

only the seconds specifier is required. here are a couple of examples:

- 1:23:45.67

  - 2:0.001

  ## FORMATS

the **--duration** option can have also an optional modifier. if this modifier is not used, then the value provided with the corresponding cut option will be interpreted as a number of samples. since most of the times will be difficult to specify a duration in terms of samples, the following modifiers are provided:

- **j**

  value is interpreted as milliseconds.

- **m**

  value is interpreted as minutes.

- **s**

  value is interpreted as seconds.

- **b**

  value is interpreted as bytes.

- **k**

  value is interpreted as kbytes (1024 bytes).

- **M**

  value is interpreted as megabytes (1024 kbytes).

in either case, the values specified will be rounded to get an integer number of samples.

## EXAMPLE

suppose you want to fade in and out the fantastic song *live.in.concert.wav* using a fade duration of 5 seconds:

- first we are going to test:

  **qwavfade -t -d 7s live.in.concert.wav**

- hear the test fades:

  **my-favourite-wav-player fadein.live.in.concert.wav**\
   **my-favourite-wav-player fadeout.live.in.concert.wav**

if you want to try with another duration, jump to the first step and change the duration argument.

- and if you're happy with the tests:

  **qwavfade -d 5s live.in.concert.wav**

## NOTES

**qwavfade** doesn't allow both types of fades (in and out) to overlap. if you want to fade in and out a wav file, and the two regions to fade overlap, then probably you made a mistake. in any case, you can do it fading separately.

## BUGS

tests has been done only with 44100 Hz 16 bit stereo files, though it may work with mono/stereo 8/16 bits files.

## AUTHOR

dmanye@etse.urv.es\
 http://www.etse.urv.es/~dmanye/quelcom/quelcom.html

## SEE ALSO

[**qwavinfo**(1)](/qwavinfo/1.md), [**qwavjoin**(1)](/qwavjoin/1.md), [**qwavcut**(1)](/qwavcut/1.md), [**qwavsilence**(1)](/qwavsilence/1.md), [**qwavheaderdump**(1)](/qwavheaderdump/1.md)\
 [**qmp3info**(1)](/qmp3info/1.md), [**qmp3join**(1)](/qmp3join/1.md), [**qmp3cut**(1)](/qmp3cut/1.md), [**qmp3check**(1)](/qmp3check/1.md), [**qmp3report**(1)](/qmp3report/1.md)