[Tips] OAuth 2.0

每次找 OAuth 2.0，就要回來看這篇
http://www.ruanyifeng.com/blog/2019/04/oauth_design.html
http://www.ruanyifeng.com/blog/2019/04/oauth-grant-types.html

[課外活動] LASS

這用的感測器研究一下

https://paditch.com/

[Google] Dialogflow線上教學

https://cloud.google.com/training/courses/conversational-experiences-dialogflow 不過要收費 QQ

[AI] 各項簡介

挺會簡介的 https://medium.com/@xiaosean5408

[RPi] Raspbian Buster更新指令

通常拿到 Pi 之後安裝完 Raspbian 第一件事就是做更新，使用 apt-get update。

但換到 buster 以後如果更新出現以下錯誤訊息

E: Repository 'http://raspbian.raspberrypi.org/raspbian buster InRelease' changed its 'Suite' value from 'testing' to 'stable'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.

可以使用這指令更新。

sudo apt-get update --allow-releaseinfo-change

參數介紹：

    --allow-releaseinfo-change
           Allow the update command to continue downloading data from a repository which changed its information of the release contained in
           the repository indicating e.g a new major release. APT will fail at the update command for such repositories until the change is
           confirmed to ensure the user is prepared for the change. See also apt-secure(8) for details on the concept and configuration.

* reference:
https://www.raspberrypi.org/forums/viewtopic.php?f=91&t=245022

[Tips] MOV 轉 MP4 並且縮小檔案

# 這應該最好用吧
avconv -i input.mov -s 1920x1080 -strict -2 output.mp4

ffmpeg -i input.mov -vcodec copy -acodec copy input.mp4
ffmpeg -i input.mp4 -vf "scale=iw/2:ih/2" -strict -2 half_the_frame_size.mp4  

* https://www.youtube.com/watch?v=8GNlfK8G_AI
* https://stackoverflow.com/questions/12026381/ffmpeg-converting-mov-files-to-mp4
* https://unix.stackexchange.com/questions/28803/how-can-i-reduce-a-videos-size-with-ffmpeg

[宅] 開源會議管理系統 badgeprint

上次去 HKOSCon2019 看到這個，之前本來想做但沒做。下次可以自己做吧
https://sammy.hk/%E9%96%8B%E6%BA%90%E6%9C%83%E8%AD%B0%E7%AE%A1%E7%90%86%E7%B3%BB%E7%B5%B1-badgeprint/