用 NN 演算法重製 Full HD 版的 Star Trek: DS9

看到「Remastering Star Trek: Deep Space Nine With Machine Learning」這篇,裡面用了類神經網路演算法,將本來只有 480p (SD) 的 Star Trek: DS9 升到 1080p (Full HD) 的版本,而且看起來效果還不錯...

意外的看到有人拿 Star Trek 的材料來玩... 依照作者的說明,DS9 一直沒有 Full HD 版的其中一個原因反而是因為「數位化」了。使用類比膠卷的母帶可以透過更高規格的重新掃描而得到高畫質版本,但 DS9 的母帶似乎已經是數位版了,所以反而造成無法透過重新掃描的方式取得 Full HD 版本:

While you can rescan analog film at a higher resolution, video is digital and can't be rescanned. This makes it much costlier to remaster this TV show, which is one of the reasons why it hasn't happened.

現有的 upscale 技術主要都還是以圖片為主,所以作者本來以為對於動態畫面的處理會遇到問題,但蠻意外的超出預期,從影片可以看出來:

看起來之後的 remaster 版本有可能可以靠這個方法先做初步,然後再讓人進去修?

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...

HP 的 audio driver 內含 Keylogger

HP 被發現 2015 年簽出來的 audio driver 內含 keylogger (yeah,因為有數位簽名,所以賴不掉...):「[EN] Keylogger in Hewlett-Packard Audio Driver」。完整的報告在「modzero Security Advisory: Unintended/Covert Storage Channel for sensitive data in Conexant HD Audio Driver Package. [MZ-17-01]」這邊。

keylogger 記錄後會寫到 local file 裡。來拉板凳...

Backblaze 再次發表各家硬碟耐用程度...

今年年初 (一月) 的時候發表過一次「各家硬碟的耐用程度...」引起爭議厚的最新力做,九月再發表一次:「Hard Drive Reliability Update – Sep 2014」。

灰色部份是一月的數據,其他顏色是九月的數據。文中有考慮是否要換成企業級的硬碟 (enterprise drives),但兩個評估的答案是否定的。

第一個評估是成本考量,就算一般硬碟以三年保固期有 15% 的 failure rate,相較於企業級 0% failure rate 計算 (於是直接算成 10 年),成本是不划算的:

Today on Amazon, a Seagate 3 TB “enterprise” drive costs $235 versus a Seagate 3 TB “desktop” drive costs $102. Most of the drives we get have a 3-year warranty, making failures a non-issue from a cost perspective for that period. However, even if there were no warranty, a 15% annual failure rate on the consumer “desktop” drive and a 0% failure rate on the “enterprise” drive, the breakeven would be 10 years, which is longer than we expect to even run the drives for.

更何況企業級硬碟的情況根本沒什麼差:

The assumption that “enterprise” drives would work better than “consumer” drives has not been true in our tests. I analyzed both of these types of drives in our system and found that their failure rates in our environment were very similar — with the “consumer” drives actually being slightly more reliable.