jjgod / blog Random notes & thoughts.


Optimizing SHA-1 Performance on OS X

At work we need to do some SHA-1 verification on application startup, naturally we want it to run as fast as possible — no user likes their browser bounce too many times on the dock before showing up. The initial implementation is extremely naïve one, yet quite portable. It’s base on Chromium’s (which our code […]

Preserving Extended Attributes on OS X

When codesigning a Mach-O file (OS X executables or libraries), the signature information will be stored in the file itself through some Mach-O extension. When codesiging a bundle (.app or .framework), _CodeSignature directory will be created. But what happens when you codesigning a plain text file? Signature information will be stored in extended attributes. Because […]


Codesigning is one of the worst issues we had been having since we started working on the new Opera for Mac. How Apple managed to screw this up never ceased to amaze us. Since yesterday morning our build servers started to get CSSMERR_TP_NOT_TRUSTED error while code signing the Mac builds. Well, we didn’t notice until […]

Mac 连接环绕立体声系统

在家看电影这么久,老早就在琢磨要不要换一个更强大一点的 5.1 环绕立体声系统,因为空间有限,专业的音响系统用不上也听不出差别,最近 XBMC 出了一个模拟立体声的 bug,让我又开始想要不要换到用数字输出才不浪费大部分 BluRay rip 里的 DTS 5.1 音频了。 Mac 的数字音频输出有两种方式,通过集成的数字/模拟音频输出 3.5mm 口用 TOSLINK 线,或者通过 HDMI。因为我用来放电影的 Mac mini 还是 2009 年的型号,所以用 TOSLINK 是唯一的解法。注意 TOSLINK 相比 HDMI 的限制是由于带宽所限无法直接输出 DTS HDMA 或者 Dolby TrueHD 的音频,但考虑到 OS X 的限制即使是用 HDMI 也无法直接输出这两种格式的,所以也就没啥好说的了。 硬件选择上,一开始考虑选择低端的数字音频解码器,比如 Yamaha RX-V473 或者 Pioneer VSX-527-S,价位相近,2000 ~ 3000 kr。优点是这两款低端的解码器对于我的需求来说都绰绰有余了,而且都支持 7.1 的 HD 音频,日后升级也有余地。缺点也很明显,单有解码器只解决一半问题,至少还得买一套 5.1 […]

My new job

In my previous post I talked about leaving Nokia and the Qt community. So what am I joining? Turned out I’m staying in Oslo for Opera Software. Why? There are a few reasons. When I applied for a job at Nokia, Qt Development Frameworks, I also sent my resume to Opera. But their response came […]

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