HP Prime has a button that can be used to express degrees minutes and seconds or, hours minutes and seconds it is the a b/c fraction button and it is a shifted operation.
Type the number of hours, press the key, then the number of minutes press the key and then the number of seconds and press the key.
This way we can perform calculations that are time based
Haven’t posted for a while, but in the meantime i have been active getting licensed as an amateur radio operator.
Got all three license levels in Uk
Foundation callsign MM7CVA
Intermediate 2M0HTP
Full MM0NKK
Also became a member of oarc online community https://wiki.oarc.uk/start?do=profile
And the Livingston and district amateur radio club https://www.ladars.org.uk/cms/
Its fun, lots of things to learn and do.
Here is a breakdown of modern python development tools https://pycon.switowski.com/02-packages/pipx/
This usually happens when the nfs server is down, you cannot umount
the nfs mount, because the system will say "not found or server not
reachable"
$ sudo umount /opt/logs/production umount.nfs: nfs.local:/var/lib/backup: not found / mounted or server not reachable umount.nfs: nfs.local:/var/lib/backup: not found / mounted or server not reachable
$ sudo umount -f -l /opt/logs/production
where -f is to do force unmount, and -l is for lazy unmounting. From man:I learned recently about the fzf linux cli command. This is a text finder similar to grep but a lot more powerful. It can be used not only to find text but files as well in an interaftive mode.
It exists as a package for debian and its github page is: https://github.com/junegunn/fzf
https://gist.github.com/steven2358/ba153c642fe2bb1e47485962df07c730
First convert the subtitles to .ass format: ```` ffmpeg -i sub.srt sub.ass ```` Then add them using a video filter: ```` ffmpeg -i in.mp4 -vf ass=sub.ass out.mp4 ```` ## Extract the frames from a video To extract all frames from between 1 and 5 seconds, and also between 11 and 15 seconds: ```` ffmpeg -i in.mp4 -vf select='between(t,1,5)+between(t,11,15)' -vsync 0 out%d.png ```` To extract one frame per second only: ```` ffmpeg -i in.mp4 -fps=1 -vsync 0 out%d.png ```` ## Rotate a video Rotate 90 clockwise: ```` ffmpeg -i in.mov -vf "transpose=1" out.mov ```` For the transpose parameter you can pass: ```` 0 = 90CounterCLockwise and Vertical Flip (default) 1 = 90Clockwise 2 = 90CounterClockwise 3 = 90Clockwise and Vertical Flip ```` Use `-vf "transpose=2,transpose=2"` for 180 degrees. ## Download "Transport Stream" video streams 1. Locate the playlist file, e.g. using Chrome > F12 > Network > Filter: m3u8 2. Download and concatenate the video fragments: ```` ffmpeg -i "path_to_playlist.m3u8" -c copy -bsf:a aac_adtstoasc out.mp4 ```` If you get a "Protocol 'https not on whitelist 'file,crypto'!" error, add the `protocol_whitelist` option: ```` ffmpeg -protocol_whitelist "file,http,https,tcp,tls" -i "path_to_playlist.m3u8" -c copy -bsf:a aac_adtstoasc out.mp4 ```` ## Mute some of the audio To replace the first 90 seconds of audio with silence: ```` ffmpeg -i in.mp4 -vcodec copy -af "volume=enable='lte(t,90)':volume=0" out.mp4 ```` To replace all audio between 1'20" and 1'30" with silence: ```` ffmpeg -i in.mp4 -vcodec copy -af "volume=enable='between(t,80,90)':volume=0" out.mp4 ```` ## Deinterlace Deinterlacing using "yet another deinterlacing filter". ```` ffmpeg -i in.mp4 -vf yadif out.mp4 ```` ## Create a video slideshow from images Parameters: `-r` marks the image framerate (inverse time of each image); `-vf fps=25` marks the true framerate of the output. ```` ffmpeg -r 1/5 -i img%03d.png -c:v libx264 -vf fps=25 -pix_fmt yuv420p out.mp4 ```` ## Extract images from a video - Extract all frames: `ffmpeg -i input.mp4 thumb%04d.jpg -hide_banner` - Extract a frame each second: `ffmpeg -i input.mp4 -vf fps=1 thumb%04d.jpg -hide_banner` - Extract only one frame: `ffmpeg -i input.mp4 -ss 00:00:10.000 -vframes 1 thumb.jpg` ## Metadata: Change the title ```` ffmpeg -i in.mp4 -map_metadata -1 -metadata title="My Title" -c:v copy -c:a copy out.mp4