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)