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Published Mar 2, 2017
Neat article I found. I'm used to doing circuit board stuff; underhood wiring is new to me, so this was a big help.
 
Published Feb 28, 2017
Handy little script to concatenate video files. Probably wouldn't recommend it with dissimilar files, though.
123456789101112
#!/bin/bash

if [[ -z $1 || -z $2 ]]; then
        echo "Must supply at least two arguments.";
        return 1;
fi

ext=`echo $1 | sed -e "s/.*\.//"`;

ffmpeg -f concat -safe 0 \
       -i <(for f in "$@"; do echo "file '$PWD/$f'"; done) \
       -c copy output.$ext
 
Published Feb 26, 2017
Had an annoying bug that didn't seem to show up on google... so maybe this will resolve some issues.
I have a makefile where a build is attempted, but because the build tool is buggy, sometimes it fails for no reason. So I invoke it with a timeout, then test to see if it errored out, and if so I rerun the build. The error code in bash is $?; but inside of a makefile the $ needs to be escaped, so I write
if [ $$? -ne 0]; then
.
However, if you need to stick this into a makefile #define block, you need to escape the escaped $. If you don't, you'll get this error: -ne: unary operator expected. So you'll have to do this:
if [ $$$$? -ne 0 ]; then
in order to escape things properly.
 
Published Feb 21, 2017
I had an issue where a video file had embedded (soft) subtitles with an error, and I wanted to edit the subtitles. Since it's just a stream in the file, it's really easy - at least for an mkv container.
All you need to do is extract the subtitles, edit them in your editor of choice, then add the stream back in. There's probably an easier way, but I removed the subtitle stream from the file entirely then added the edited one back.
1234
ffmpeg -i <video.mkv> -an -vn -map 0:2 -c:s:0 srt <sub.srt>
vi <sub.srt>
ffmpeg -i <video.mkv> -c:v copy -c:a copy -sn <video_nosub.mkv>
ffmpeg -i <video_nosub.mkv> -i <sub.srt> -c:v copy -c:a copy -c:s srt <video_output.mkv>
 
Published Jan 30, 2017
"Release 5.1 is a disappointment. Performance for common operations has dropped 40% from 4.0.5, we shipped with 500 priority 1 and 2 bugs, and a base Indy is much more sluggish than a Macintosh. Disk space requirements have increased dramatically.
The primary cause is that we attempted far too much in too little time. Management would not cut features early, so we were forced to make massive cuts in the final weeks of the release.
What shall we do now? Let's not look for scapegoats, but learn from our mistakes and do better next time."
 
Published Jan 27, 2017
This document is a collection of facts about ASCII and related technologies, notably hardware terminals and RS-232 and modems. This is lore that was at one time near-universal and is no longer. Itís not likely to be directly useful today - until you trip over some piece of still-functioning technology where itís relevant (like a GPS puck), or it makes sense of some old-fart war story. Even so, itís good to know anyway, for cultural-literacy reasons.
 
Published Jan 10, 2017
Looks like the backdoor roth will still be good for 2017.
If you're above the roth contribution income limits, it works like this:
1. Contribute to Traditional IRA
2. Convert (not recharacterize) to Roth IRA.
 
Published Dec 8, 2016
So... why does
calloc
exist, if it's equivalent to these 2 lines? The C library is not known for its excessive focus on providing convenient shorthands!
It turns out there are actually two differences between calling
calloc
, versus calling
malloc + memset
.
 
 
Archive: November 2016 »
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