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), qwavjoin(1), qwavcut(1), qwavsilence(1), qwavheaderdump(1)
       qmp3info(1), qmp3join(1), qmp3cut(1), qmp3check(1), qmp3report(1)