Twitch 用 VP9 直播...

Twitch 整理了一篇「How VP9 delivers value for Twitch’s esports live streaming」,說明他們用 VP9 的經驗談。

裡面有很大的篇幅是在講 VP9 與 H.264 的比較,不過這兩個用的技術就已經不是同一個年代了,沒有進步的話就不用出來玩了...

裡面有講到一些有趣的東西,像是提到是用 FPGA 即時壓縮:

In this article, we will show that the FPGA-based real-time VP9 encoding can deliver at least 25% bitrate savings compared to the highest-quality H.264 encoders deployed in Twitch’s production today.

然後提到 1080p60 至少省了 25% 的頻寬 (這邊應該是相較於 H.264):

VP9’s Compression Efficiency for Live 1080p60 Encoding: We Can Achieve At Least 25% Bitrate Savings

查了一下,在桌機上的瀏覽器都差不多支援了:

VP9 is implemented in these web browsers:

Chromium and Google Chrome (usable by default since version 29 from May and August 2013, respectively),
Opera (since version 15 from July 2013),
Mozilla Firefox (since version 28 from March 2014),
Microsoft Edge (as of summer 2016).

行動裝置的話 Android 4.4+ 有支援,但在 iOS 上沒有支援...

整體看起來普及率算是不低,可以引入當主力 codec 降低頻寬成本,當設備不支援 VP9 時 (應該只有 iOS 透過 Safari 觀看的情況) 就用 H.264 stream 提供服務。

Chrome 72+ (目前在 Beta 的版本) 對延伸套件的影響

我的桌機平常都是跑 beta channel 的 Chrome,所以前陣子已經升級到 72,然後發現兩個問題:

從 dev console 可以看到問題都是 Referer 沒被送出,導致有檢查 Referer 的網站拒絕存取,後來在「chrome.webRequest」這邊發現是 Chrome 72+ 改了規則,裡面提到了:

Starting from Chrome 72, the following request headers are not provided and cannot be modified or removed without specifying 'extraHeaders' in opt_extraInfoSpec:

Accept-Language
Accept-Encoding
Referer
Cookie

Starting from Chrome 72, the Set-Cookie response header is not provided and cannot be modified or removed without specifying 'extraHeaders' in opt_extraInfoSpec.

不確定這個設計的目的是什麼,但反正已經中獎了,總是得回報給各 extension 的維護者讓他們修正 (用 beta channel 的重要任務之一?)。

所以就先去 Tampermonkey 開 ticket,也很迅速的在 beta 版修正了 (所以只能先改裝 beta 版):「GM_xmlhttpRequest unable to set referer in Chrome 72+ #629」。

另外跟 Referer Control 的開發者回報這個問題,也修正出新版上架了,更新就生效了:「refererControlDisqus.html」。

目前看起來還有「Spoofs Lang」得修,不過這個軟體好久沒更新了,不知道有沒有機會...

24 Core 的 ARM Server...

在「Banana Pi to Launch a 24-Core Arm Server」這邊看到 Banana Pi 打算推出 24 core 的 ARM server...

看起來還蠻不錯的:

We have 24-core Arm Cortex A53 processor with 32GB RAM (29.4GB seen by the OS) running Ubuntu 18.04.1 LTS with MATE desktop. There aren’t that many 24-core Arm Cortex A53 processors, so unless the company is using an announced processor, it has to be SocioNext SC2A11 processor also found in Linaro Developer Box.

拿來當 desktop 好像也不錯,不知道最終的定價會是多少...

2018 年矽谷科技公司的薪資

不太意外的,排名起來加州這一區的科技公司的薪資還是最高的 (這邊包括了所有的所得,包括薪資、股票與分紅):「Top Paying Tech Companies of 2018」。

已經先整理出來的前五名分成「Entry-level / 1+ Yrs of Experience」、「Mid-level / 3+ Yrs of Experience」、「Been Around the Block / 5+ Yrs of Experience」三類,可以看到相對於年資的增加,薪資的調整也很快...

不過這邊相同名次的不會佔多個位置,只會佔一名,跟我們平常用的方式不太一樣,所以雖然是前五名但是都有六個公司。

加拿大禁止透過 ISP 發送版權侵害通知

因為被濫用的關係,加拿大決定禁止版權擁有人透過 ISP 發送版權侵害通知:「Canada Prohibits Piracy Settlement Demands in ISP Copyright Notices」。

不過這個限制是有條件的,只有當通知裡面有包括任何形式的協議時才會被禁止:

Moving forward, rightsholders will not be allowed to send copyright infringement notices for ISPs to pass onto their customers, if they contain a direct or indirect offer to settle.

TorrentFreak 的文章裡也提到了,就是要阻止這樣的行為變成「產業」:

The development effectively ends Rightscorp-style business models in Canada.

這是條文:

Bill C-86, the Budget Implementation Act, has now received royal assent, so there will be some big changes in the Great White North. Section 41.‍25 of the Copyright Act is now amended with the addition of the following;

(3) A notice of claimed infringement shall not contain:

(a) an offer to settle the claimed infringement;
(b) a request or demand, made in relation to the claimed infringement, for payment or for personal information;
(c) a reference, including by way of hyperlink, to such an offer, request or demand; and
(d) any other information that may be prescribed by regulation.

Percona 推出 MySQL 8.0 的對應版本了...

Percona 在過節前推出 Percona Server for MySQL 8.0 了:「Announcing General Availability of Percona Server for MySQL 8.0」。

Oracle 版的 MySQL 8.0 多了不少功能,像是往 NoSQL 靠的功能與 GIS 相關的功能,但讓我注意到的是 Percona 自己的事情... TokuDB 因為 MyRocks 而要被放生了:

Features Being Deprecated in Percona Server for MySQL 8.0
TokuDB Storage Engine: TokuDB will be supported throughout the Percona Server for MySQL 8.0 release series, but will not be available in the next major release. Percona encourages TokuDB users to explore the MyRocks Storage Engine which provides similar benefits for the majority of workloads and has better optimized support for modern hardware.

AWS 提供 OpenVPN-based VPN 服務

不知道為什麼在 feed reader 裡面沒注意到這則,後來是在 Facebook 上看到的。

AWS 推出了 OpenVPN-based 的 VPN 服務 AWS VPN:「Introducing AWS Client VPN to Securely Access AWS and On-Premises Resources」。

看起來是這個價錢:

AWS Client VPN pricing
$0.05 per AWS Client VPN connection hour
$0.10 per AWS Client VPN endpoint association hour

所以服務本身的費用要 $72/month 左右,另外 client 接上去的費用另外算?

目前支援的區域有限,暫時只有歐美的大區:

AWS Client VPN is available in US East (Virginia), US East (Ohio), US West (Oregon) and EU (Ireland) AWS Regions. Support for other AWS Regions is coming soon.

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