Tag Archives: vp9

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。

Cisco 開發新的 Video Codec:Thor

Cisco 開發新的 Video Codec 與 HEVC (H.265) 競爭,專案名稱叫做 Thor:「World, Meet Thor – a Project to Hammer Out a Royalty Free Video Codec」。

沒什麼意外,專利問題是主要的原因:

Unfortunately, the patent licensing situation for H.265 has recently taken a turn for the worse. Two distinct patent licensing pools have formed so far, and many license holders are not represented in either. There is just one license pool for H.264. The total costs to license H.265 from these two pools is up to sixteen times more expensive than H.264, per unit. H.264 had an upper bound on yearly licensing costs, whereas H.265 has no such upper limit.

不過一開頭寫到 VP9 是 proprietary 的描述讓人很不解:

There are two of note – Google’s proprietary VP9 codec, and the industry standard H.265 (HEVC) codec, which is the successor to H.264 (AVC).

往下拉 comment 看果然就有人提出來:

How exactly is VP9 more "proprietary" than Thor? Both are open sourced under BSD license, both are royalty free, both are intended to be unencumbered by patents. Are you defining "proprietary" as "not controlled by Cisco"?

不知道在搞什麼鬼...