A minimal screenshot utility for X11. Shotgun was written to replace maim in my workflow.
Features: - Exports PNG screenshots to file or stdout - Masks off-screen areas on multi-head setups - Supports selections by window ID and geometry - On average, shotgun is more than twice as fast as maim
``` Usage: shotgun [options] [file]
Options: -i, --id ID Window to capture -g, --geometry WxH+X+Y Area to capture -f, --format png/pam Output format -s, --screen Capture the current screen -h, --help Print help and exit -v, --version Print version and exit ```
```sh
selection=$(hacksaw -f "-i %i -g %g") shotgun $selection - | xclip -t 'image/png' -selection clipboard ```
maim -s):```sh
sel=$(slop -f "-i %i -g %g") shotgun $sel "$1" ```
- as the file name if you want to pipe output to something
else)There are several reasons for omitting these features:
- Features that can be replaced trivially by external programs and wrapper
scripts:
- Use ImageMagick's convert and shotgun's -f pam for JPEG output
- slop output is easy to process in a shell script
- Use sleep instead of -d, since slop has to be called separately, this
flag is not necessary
- -x shouldn't even exist in the first place, set $DISPLAY instead
- I never use cursor blending, and I know that most users do not actually care
for it
- -w (geometry relative to another window) is difficult to use and hardly
useful, instead, shotgun always interprets the input geometry relative to the
root window (maim's default is the captured window itself)
- There is rarely a reason to take a screenshot of an XShape window, most of
them are special like slop's selection window or keynav's crosshair.
Supporting XShape properly could add a significant amount of overhead, both in
code length and performance, which are not desirable.
I've claimed that shotgun is twice as fast as maim, here's some supporting
evidence (using hyperfine):
``` $ xrandr --fb 3840x2160 $ hyperfine --warmup 15 --min-runs 50 \
'maim > /dev/null' \ 'shotgun - > /dev/null'Benchmark #1: maim > /dev/null Time (mean ± σ): 629.3 ms ± 3.7 ms [User: 570.7 ms, System: 52.1 ms] Range (min … max): 624.8 ms … 646.7 ms 50 runs
Benchmark #2: shotgun - > /dev/null Time (mean ± σ): 293.0 ms ± 3.2 ms [User: 239.6 ms, System: 52.9 ms] Range (min … max): 287.8 ms … 298.2 ms 50 runs
Summary 'shotgun - > /dev/null' ran 2.15 ± 0.03 times faster than 'maim > /dev/null' ```
Further profiling has shown that the bottleneck in shotgun lies fully within the PNG encoder.
The PNG encoder bottleneck can be avoided by using -f pam. This sets the output format to
Netpbm PAM - an uncompressed binary image format.
By using an uncompressed format both encoding and decoding performance is improved:
``` $ hyperfine --warmup 15 --min-runs 50 \
'shotgun -f png - > /dev/null' \ 'shotgun -f pam - > /dev/null'Benchmark #1: shotgun -f png - > /dev/null Time (mean ± σ): 294.5 ms ± 3.3 ms [User: 240.0 ms, System: 54.1 ms] Range (min … max): 289.2 ms … 301.4 ms 50 runs
Benchmark #2: shotgun -f pam - > /dev/null Time (mean ± σ): 116.8 ms ± 2.8 ms [User: 62.5 ms, System: 53.7 ms] Range (min … max): 113.8 ms … 122.7 ms 50 runs
Summary 'shotgun -f pam - > /dev/null' ran 2.52 ± 0.07 times faster than 'shotgun -f png - > /dev/null' ```
``` $ hyperfine --warmup 15 --min-runs 50 \
'shotgun -f png - | convert - jpg:- > /dev/null' \ 'shotgun -f pam - | convert - jpg:- > /dev/null'Benchmark #1: shotgun -f png - | convert - jpg:- > /dev/null Time (mean ± σ): 600.7 ms ± 5.8 ms [User: 506.4 ms, System: 96.5 ms] Range (min … max): 594.9 ms … 620.7 ms 50 runs
Benchmark #2: shotgun -f pam - | convert - jpg:- > /dev/null Time (mean ± σ): 350.4 ms ± 3.9 ms [User: 217.0 ms, System: 139.3 ms] Range (min … max): 345.5 ms … 367.8 ms 50 runs
Summary 'shotgun -f pam - | convert - jpg:- > /dev/null' ran 1.71 ± 0.03 times faster than 'shotgun -f png - | convert - jpg:- > /dev/null' ```
cargo install --path .cargo install shotgunpacman -S shotgunnixpkgs.shotgun