qwavfade(1)							 quelcom man pages						       qwavfade(1)

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 con-
       sists 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 sim-
	      ilar to the --duration option above. its easier to use though not as powerful than the previous one. the default value is five  sec-
	      onds. 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)

quelcom 0.4.0							   february 2001						       qwavfade(1)