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...

利用 Side-channel 資訊判斷被 HTTPS 保護的 Netflix 影片資訊

在「Netflix found to leak information on HTTPS-protected videos」這篇看到了研究員透過 VBR 所透露出的 side channel 資訊,成功的取得了被 HTTPS 保護的 Netflix 影片資訊。這對於美國的 ISP 是個大利多 (加上之前通過的法案),但對於個人隱私則是嚴重的打擊。

這項研究的準確率非常高:

To support our analysis, we created a fingerprint database comprised of 42,027 Netflix videos. Given this collection of fingerprints, we show that our system can differentiate between videos with greater than 99.99% accuracy. Moreover, when tested against 200 random 20-minute video streams, our system identified 99.5% of the videos with the majority of the identifications occurring less than two and a half minutes into the video stream.

而且他們居然是用這樣的單機分析:

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苦啊...

收 Wikimedia (包括維基百科) 的 Recent Changes

所以有新的 streaming protocol 取代本來的 RCStream:「Get live updates to Wikimedia projects with EventStreams」。

這次新的 protocol 是走標準協定:

EventStreams is built on the w3c standard Server Sent Events (SSE). SSE is simply a streaming HTTP connection with event data in a particular text format. Client libraries, usually called EventSource, assist with building responsive tools, but because SSE is really just HTTP, you can use any HTTP client (even curl!) to consume it.

直接用瀏覽器打開也可以看到一直冒出來新的訊息...

Amazon 決定在自家的購物網站上停售 Google Chromecast 與 Apple TV

這大概是這幾天最刺激的事情... Amazon 決定在自家購物往站上停售 Google ChromecastApple TV:「Amazon to Ban Sale of Apple, Google Video-Streaming Devices」。

引用新聞的報導說明,因為 Chromecast 與 Apple TV 不相容於 Amazon 自家的 Prime Video,所以下令所有的店家停售:

The Seattle-based Web retailer sent an e-mail to its marketplace sellers that it will stop selling the Apple TV and Google’s Chromecast since those devices don’t "interact well" with Prime Video. No new listings for the products will be allowed and posting of existing inventory will be removed Oct. 29, Amazon said. Prime Video doesn’t run easily on its rival’s hardware.

至於會不會引起反壟斷調查呢?站在看好戲的立場當然是很希望,但這兩個產品就算不在 Amazon 上買,也有一卡車的競爭對手有賣... 不曉得後面會怎麼發展。

關於 KeyCDN 的 HLS streaming 最佳化...

KeyCDN 發表了對 HLS streaming 的最佳化:「New feature: Optimized HLS streaming」。

其中這段看起來就很奇怪:

The index file (.m3u8) will not be cached at all. The .ts files will only be cached for 5 minutes. If the origin server sends other Cache Control headers, it will be ignored by the CDN.

也就是這個畫面:

如果你把對 .m3u8 的壓力全部打到後端,那麼就註定不 scale 啊?之前在 EC2 c3.8xlarge 上面用 Wowza 測試,就發現單台最多只能承受 4000 reqs/sec。

比較好的作法應該是 cache 很短的時間 (也許三到五秒),讓 CDN 幫你擋下來,而不是前面打多少 reqs/sec 後面就吃多少...

在 Flash 上播 HLS...

靠的是「Apple’s HTTP Live Streaming (HLS) in Flash !」這篇「2014/02/12 的 comment」解的 (不是原文內的方法)。

專案在 GitHub 上:「HLSProvider is a Flash/AS3 plugin that plays back HLS streams」。

使用方式與範例可以在「HLSprovider/test/flowplayer at master · mangui/HLSprovider」這邊翻到,直接看 index.html,並且把 swf 檔弄出來就可以動了。

不過實際測試發現 buffer 的部份好像處理的不是很好... 但至少有東西可以用了 :o