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
-
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)