1 .TH XScreenSaver 1 "" "X Version 11"
3 glitchpeg - glitched image screen saver.
6 [\-display \fIhost:display.screen\fP]
7 [\-visual \fIvisual\fP]
10 [\-delay \fInumber\fP]
11 [\-duration \fInumber\fP]
12 [\-count \fInumber\fP]
14 Loads an image, corrupts it, and then displays the corrupted version,
15 several times a second. After a while, finds a new image to corrupt.
17 It glitches the image by altering random bytes in the compressed image
18 file before de-compressing it. This creates interesting visual effects
19 on JPEG files, but doesn't work well on PNG files, since PNG contains
20 checksums that detect simple corruption.
23 .B \-visual \fIvisual\fP
24 Specify which visual to use. Legal values are the name of a visual class,
25 or the id number (decimal or hex) of a specific visual.
28 Draw on a newly-created window. This is the default.
31 Draw on the root window.
33 .B \-delay \fInumber\fP
34 Per-frame delay, in microseconds. Default: 30000 (0.03 seconds).
36 .B \-duration \fInumber\fP
37 How many seconds before loading a new image. Default: 120.
39 .B \-count \fInumber\fP
40 Number of glitches to introduce per iteration. Default: 100.
45 to get the default host and display number.
48 to get the name of a resource file that overrides the global resources
49 stored in the RESOURCE_MANAGER property.
51 Because this program is feeding intentionally-invalid data into your
52 operating system's image-decoding libraries, it is possible that it
53 may crash as a result of that corrupted data.
55 That should not be possible -- but it might be.
57 Please note that if this happens, that indicates a serious security
58 bug in your system's image libraries! It likely means that your
59 libraries are susceptible to buffer overflow attacks or similar, which
60 can lead to remote code execution. You should report that bug to the
61 maintainers of those image libraries.
63 In the context of xscreensaver, when configured to load only local
64 image files, this should not be a direct security concern: this screen
65 saver crashing will not affect the xscreensaver daemon and will not
71 Copyright \(co 2018 by Jamie Zawinski. Permission to use, copy, modify,
72 distribute, and sell this software and its documentation for any purpose is
73 hereby granted without fee, provided that the above copyright notice appear
74 in all copies and that both that copyright notice and this permission notice
75 appear in supporting documentation. No representations are made about the
76 suitability of this software for any purpose. It is provided "as is" without
77 express or implied warranty.