A few hours ago I ended my webinar on how to get your code contribution merged into curl. Here’s the video of it:
Here are the slides.
Tag Archives: video
Video: testing curl for security
The webinar from June 30, now on video. The slides are here.
video: common mistakes when using libcurl
As I posted previously, I did a webinar and here’s the recording and the slides I used for it.
libcurl video tutorial
I’ve watched how my thirteen year old son goes about to acquire information about things online. I am astonished how he time and time again deliberately chooses to get it from a video on YouTube rather than trying to find the best written documentation for whatever he’s looking for. I just have to accept that some people, even some descendants in my own family tree, prefer video as a source of information. And I realize he’s not alone.
So therefore, I bring you, the…
libcurl video tutorial
My intent is to record a series of short and fairly independent episodes, each detailing a specific libcurl area. A particular “thing”, feature, option or area of the APIs. Each episode is also thoroughly documented and all the source code seen on the video is available on the site so that viewers can either follow along while viewing, or go back to the code afterward as a reference. Or both!
I’ve done the four first episodes so far, and they range from five minutes to nineteen minutes a piece. I expect that it might take me a while to just complete the list of episodes I could come up with myself. I also hope and expect that readers and viewers will think of other areas that I could cover so the list of video episodes could easily expand over time.
Feedback
If you have comments on the episodes. If you have suggestion of what to improve or subjects to cover, head over to the libcurl-video-tutorials github page and file an issue or two!
Video setup
I use a Debian Linux installation to develop on. I figure it should be similar enough to many other systems.
Video wise, in each episode I show you my text editor for code, a terminal window for building the code, running what we build in the episode and also for looking up man page information etc. And a small image of myself. Behind those three squares, there’s a photo of a forest (taken by me).
I plan to make each episode use the same basic visuals.
In the initial “setup” episode I create a generic Makefile, which we can reuse in several (all?) other episodes to build the example code easily and swiftly. I’ve previously learned that people consider Makefiles difficult, or sometimes even magic, to work with so I wanted to get that out of the way from the start and then focus more directly on actual C code that uses libcurl.
Receive data episode
Here’s the “receive data” episode as an example of how this can look.
Talk: web transport, today and tomorrow
At the Netnod spring meeting 2017 in Stockholm on the 5th of April I did a talk with the title of this post.
Why was HTTP/2 introduced, how well has HTTP/2 been deployed and used, did it deliver on its promises, where doesn’t HTTP/2 perform as well. Then a quick (haha) overview on what QUIC is and how it intends to fix some of the shortcomings of HTTP/2 and TCP. In 28 minutes.
HTTP/2 in April 2016
On April 12 I had the pleasure of doing another talk in the Google Tech Talk series arranged in the Google Stockholm offices. I had given it the title “HTTP/2 is upon us, and here’s what you need to know about it.” in the invitation.
The room seated 70 persons but we had the amazing amount of over 300 people in the waiting line who unfortunately didn’t manage to get a seat. To those, and to anyone else who cares, here’s the video recording of the event.
If you’ve seen me talk about HTTP/2 before, you might notice that I’ve refreshed the material somewhat since before.
Turn many pictures into a movie
Challenge: you have 90 pictures of various sizes, taken in different formats and shapes. Using all sorts strange file names. Make a movie out of all of them, with the images using the correct aspect ratio. And add music. Use only command line tools on Linux.
Solution: this is a solution, you can most likely solve this in 22 other ways as well. And by posting it here, I can find it myself if I ever want to do the same stunt again…
#!/bin/sh j=0 # convert options pic="-resize 1920x1080 -background black -gravity center -extent 1920x1080" # loop over the images for i in `ls *jpg | sort -R`; do echo "Convert $i" convert $pic $i "pic-$j.jpg" j=`expr $j + 1` done # now generate the movie mp3="file.mp3" echo "make movie" ffmpeg -framerate 3 -i pic-%d.jpg -i $mp3 -acodec copy -c:v libx264 -r 30 -pix_fmt yuv420p -s 1920x1080 -shortest out.mp4
Explained
This is a shell script.
The ‘pic’ variable holds command line options for the ImageMagick ‘convert‘ tool. It resizes each picture to 1920×1080 while maintaining aspect ratio and if the pic gets smaller, it is centered and gets a black border.
The loop goes through all files matching *,jpg, randomizes the order with ‘sort’ and then runs ‘convert’ on them one by one and calls the output files pic-[number].jpg where number is increased by one for each image.
Once all images have the correct and same size, ‘ffmpeg‘ is invoked. It is told to produce a movie with 3 photos per second, how to find all the images, to include an mp3 file into the output and to stop encoding when one of the streams ends – this assumes the playing time of the mp3 file is longer than the total time the images are shown so the movie stops when we run out of images to show.
Result
The ‘out.mp4’ file, uploaded to youtube could then look like this:
(music by Bensound.com)
daniel weekly 42, switching off Nagle
Topics
See you at ApacheCon on Friday!
14% HTTP/2 thanks to nginx ?
Brotli everywhere! Firefox, libbrotli
The –libcurl flaw is fixed (and it was GONE from github for a few hours)
No, the cheat sheet cannot be in the man page. But…
bug of the week: the http/2 performance fix
option of the week: -k
Talking at the GOTO Conference next week
daniel weekly 41, now in markdown
Episode 41, just out:
Topics
http2 explained in markdown, translations. Swedish?
curl feature freeze period, release october 7
Bug of the week: Downloading a long sequence of URLs results in high CPU usage and slowness
Option of the week: -O
I lead the curl project and this is how it works
I did this 50 minute talk on May 21 2015 for a Swedish company. With tongue in cheek subtitled “from hobby to world domination”. I think it turned out pretty decent and covers what the project is, how we work on it and what I do to make it run. Some of the questions are not easy to hear but in general it works out fine. Enjoy!