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不吃電池的 HD Camera Streaming...

Hacker News Daily 上看到「Towards Battery-Free HD Video Streaming」這個,不使用電池僅靠反射產生訊號,可以達到 HD 畫質的 Camera Streaming (在原型機上測試可以跑出 720p/10fps):

Finally, we design a proof-of-concept prototype with off-the-shelf hardware components that successfully backscatter 720p HD video at 10 fps up to 16 feet.

而且畫質比想像中好很多,算是比「可用」的等級還高不少:

愈來愈多在研究用 backscatter 拼一些比較複雜的應用...

Twitter 放出來的 Vireo,一套 Open Source 授權的 Video Processing Library

Twitter 放出 Vireo,一套以 MIT License 釋出的 Video Processing Library:「Introducing Vireo: A Lightweight and Versatile Video Processing Library」。專案庫在 GitHubtwitter/vireo 可以取得。

C++ 寫的,另外也已經提供 Scala 的接口,這應該是讓 Twitter 的人可以方便使用:

Vireo is a lightweight and versatile video processing library that powers our video transcoding service, deep learning recognition systems and more. It is written in C++11 and built with functional programming principles. It also optionally comes with Scala wrappers that enable us to build scalable video processing applications within our backend services.

在 Tools 的部份也可以看到很多功能,像是:

thumbnails: extracts keyframes from the input video and saves them as JPG images

viddiff: checks if two video files are functionally identical or not (does not compare data that does not affect the playback behavior)

另外要注意的是,預設不會將 GPL 的套件納入編譯,需要指定 --enable-gpl 才會編進去:

The following libraries are disabled by default. To enable GPL licensed components, they have to be present in your system and --enable-gpl flag have to be explicitly passed to configure

看起來主要就是最常見的那包... (libavformat / libavcodec / libavutil / libswscale / libx264)

Amazon Kinesis Streams 的 Video 版本:Amazon Kinesis Video Streams

這次 AWS 推出的 Amazon Kinesis Video Streams 在技術上看起來跟 Amazon Media Services 有不少重疊 (參考先前提到的文章「AWS Media Services 推出一卡車與影音相關的服務...」),但產品面上區隔開的服務:「Amazon Kinesis Video Streams – Serverless Video Ingestion and Storage for Vision-Enabled Apps」。

開頭介紹就有提到適合用在各種 IoT 裝置,用在一直有影像資料產生的設備上:

Cell phones, security cameras, baby monitors, drones, webcams, dashboard cameras, and even satellites can all generate high-intensity, high-quality video streams. Homes, offices, factories, cities, streets, and highways are now host to massive numbers of cameras.

像這張圖的所介紹的流程,以及可以保留天數的設計:

底層用了不少與 Amazon Media Services 相同的技術,但是包裝成不同的產品...

去電視廣告的服務又來了...

看到「Plex’s DVR now lets you skip the commercials… by removing them for you」這篇文章,介紹 Plex 要推出去電視廣告的服務...

維基百科上的介紹比較清楚:「Plex (software)」,主要有兩個元件組成,media server 與 player:

  • The Plex Media Server desktop application runs on Windows, macOS and Linux-compatibles including some types of NAS devices. The 'server' desktop application organizes video, audio and photos from your collections and from online services, enabling the players to access and stream the contents.
  • The media players. There are official clients available for mobile devices, smart TVs, and streaming boxes, a web app and Plex Home Theater (no longer maintained), as well as many third-party alternatives.

然後這次要推出的功能是直接在錄影的時候把廣告拿掉:

Plex confirmed it’s rolling out a new feature that will allow cord cutters to skip the commercials in the TV programs recorded using its software, making the company’s lower-cost solution to streaming live TV more compelling. Unlike other commercial-skip options, Plex’s option will remove commercials from recordings automatically.

這讓我有些印像... 當年 TiVo 也有類似的功能,不過文章裡有提到 TiVo 是提供 skip 而非直接拿掉:

The new feature works by locating the commercials in your recorded media. It then actually removes them before the media is stored in your library. That sounds like it could be even better than TiVo’s commercial skipping option, for example, because you don’t have to press a button to skip the ads — they’re being pulled out for you, proactively.

不過主要是認識了 Plex 這個軟體... 如果是電視兒童的話應該用的到 XD 台灣目前的電視節目好像看的比較少...

AWS Media Services 推出一卡車與影音相關的服務...

AWS 推出了一連串 AWS Elemental MediaOOXX 一連串影音相關的服務:「AWS Media Services – Process, Store, and Monetize Cloud-Based Video」。

但不是所有的服務都是相同的區域... 公告分別在:

不過這邊還是引用 Jeff Barr 文章裡的說明,可以看到從很源頭的 transencoding 到 DRM,以及 Live 格式,到後續的檔案儲存及後製 (像是上廣告) 都有:

AWS Elemental MediaConvert – File-based transcoding for OTT, broadcast, or archiving, with support for a long list of formats and codecs. Features include multi-channel audio, graphic overlays, closed captioning, and several DRM options.

AWS Elemental MediaLive – Live encoding to deliver video streams in real time to both televisions and multiscreen devices. Allows you to deploy highly reliable live channels in minutes, with full control over encoding parameters. It supports ad insertion, multi-channel audio, graphic overlays, and closed captioning.

AWS Elemental MediaPackage – Video origination and just-in-time packaging. Starting from a single input, produces output for multiple devices representing a long list of current and legacy formats. Supports multiple monetization models, time-shifted live streaming, ad insertion, DRM, and blackout management.

AWS Elemental MediaStore – Media-optimized storage that enables high performance and low latency applications such as live streaming, while taking advantage of the scale and durability of Amazon Simple Storage Service (S3).

AWS Elemental MediaTailor – Monetization service that supports ad serving and server-side ad insertion, a broad range of devices, transcoding, and accurate reporting of server-side and client-side ad insertion.

引個前同事的 tweet,先不說 Amazon SWF 的情況 (畢竟 Amazon SWF 還可以找到其他用途),倒是 Amazon Elastic Transcoder 很明顯要被淘汰掉了:

這種整個大包的東西是 AWS re:Invent 才有的能量,平常比較少看到...

在北美盜版 IPTV 產生的流量比 BitTorrent 還多

算是前陣子的新聞,在北美地區的盜版 IPTV 流量比 BitTorrent 的流量還多:「IPTV Piracy Generates More Internet Traffic Than Torrents」。

During peak hours, 6.5% of all downstream traffic on fixed networks is generated by TV piracy services.

To put this into perspective; this is more than all BitTorrent traffic during the peak hours, which was “only” 1.73% last year, and dropping.

如果把影音網站都考慮進去,最大的還是 YouTubeNetflix 這兩個啦,不過盜版的量也不小...

然後也有把最大的量分析出來,這裡面最大的量是 Indian Star Plus HD,應該是印度裔或是印度籍的人看家鄉的東西?

The most viewed of all in North America, with 4.6% of all pirated TV traffic, is the Indian Star Plus HD.

不過 Sandvine 一直都有方法分析整個北美流量,讓人感覺不太舒服...

YouTube 史上第一個破四十億次播放的影片:Despacito

前幾天 2017/10/11 達到了:「Luis Fonsi & Daddy Yankee's 'Despacito' Is First Clip to Hit 4 Billion Views on YouTube」。


出自「Gangnam Style (music_video)」這頁。

不到一年的時間 XD

依照這個速度,應該是下個月會破 UINT_MAX (4294967295)?當年 YouTube 的人有在 Google+ 上發了一則關於超過 INT_MAX 的 PR 稿 (不過後來刪除了):「Gangnam Style overflows INT_MAX, forces YouTube to go 64-bit」。

所以這次會發嗎?

機器學習與情色產業的問題

Bruce Schneier 提到了最近幾個剛好相關的議題,關於機器學習在情色產業使用時遇到的隱私議題:「Technology to Out Sex Workers」。

第一個提到的是 PornHub 用機器學習辨識演員以及各種「其他資訊」,這邊引用的報導是 TechCrunch 的「PornHub uses computer vision to ID actors, acts in its videos」:

PornHub is using machine learning algorithms to identify actors in different videos, so as to better index them.

The computer vision system can identify specific actors in scenes and even identifies various positions and… attributes.

第二個提到的是花名與真實身份連在一起的問題:

People are worried that it can really identify them, by linking their stage names to their real names.

最後是提到 Facebook 已經有能力這樣做,而且已經發生了:

Facebook somehow managed to link a sex worker's clients under her fake name to her real profile.

Her sex-work identity is not on the social network at all; for it, she uses a different email address, a different phone number, and a different name. Yet earlier this year, looking at Facebook’s “People You May Know” recommendations, Leila (a name I’m using using in place of either of the names she uses) was shocked to see some of her regular sex-work clients.

這個議題與 Mass surveillance 有點像...。

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