分类： Uncategorized

继续阅读当法律遇上陋习

SSH login is supposed to be fast – All it needs are a key exchange to establish a secure channel and then an authentication process, which are both trivial tasks to modern computers. However, as it often happens, a simple login might take no less than 15 seconds.

I ran into this problem recently and had a investigation. As it turned out, there are multitude of factors that might affect the speed of the SSH login process. From the most obvious the to most inconspicuous, here are them:

• The sshd_config file.

This is the main configuration file that controls the behavior of the ssh daemon. In this file, you want to make sure the following features are disabled:

继续阅读Slow SSH Login

早上在法广首页看到新闻，吓一跳。

新闻链接戳这里：

赶紧点进去看，并把新闻发给了在菲律宾做生意的朋友。同时在其它媒体找相关信息。

继续阅读法广，seriously?

在wenxuecity上看到一片文章，原文发表于3月12日，转载如下：

继续阅读转载《读《思旧赋》》

上周翻书柜，又翻出这本《From mathematics to generic programming》，再到亚马逊上一搜，果然还没有中文版。我是Alexander Stepanov的粉丝，书一出来我就上美亚买了，就是打算翻译的。

买回来之后尝试翻译了几章，然后找了XX出版社，出版社看了告诉我说他们已经签了版权了，估计6个月中文版就出来了，于是只好撂下了。哪知道如今快两年过去了，中文版也还没影。

这几天我会跟作者联系，看看版权到底是个什么状态，同时会在这里放出以前翻译的草稿，欢迎批评指正。

If you’re looking for a method to write camera pose information into JPG files so that it can be read by Pix4D, as shown in the below screenshot:

Here is how to do it with exiftool:

• First, you need a configuration file for exiftool. In the configuration file, you need the following content:

%Image::ExifTool::UserDefined = (
    'Image::ExifTool::XMP::Main' => {
        Camera=> {
            SubDirectory => {
                TagTable => 'Image::ExifTool::UserDefined::Camera',
            },
        },
    },
);
%Image::ExifTool::UserDefined::Camera = (
    GROUPS => { 0 => 'XMP', 1 => 'XMP-Camera', 2 => 'Other' },
    NAMESPACE => { 'Camera' => 'http://ns.flyingfishtechs.com/Camera/1.0/' },
    WRITABLE => 'string',
    GPSXYAccuracy=> {},
    GPSZAccuracy => {},
    Pitch => {},
    Roll=>{},
    Yaw => {},
 );

• Then you can using exiftool to add the information to any JPG file.

exiftool.exe -config config.min.cfg -Pitch="1.02" -Roll="2.03" -Pitch="3.04" original.jpg

If the command outputs: 1 image files updated. Then you’re done. Now the JPG file has the camera pose information encoded in. If you have more than 3 such pictures (only because Pix4D needs at least 3 pictures to work), you can see that Pix4D can get the data from the pictures.

The final twist, Pix4D displays Omega, Phi and Kappa instead of Pitch, Roll and Yaw. Basically, Pitch, Roll and Yaw are angles relative to the horizontal plane – orthogonal to the gravity while Omega, Phi and Kappa are related to earth. That means, with a fixed set of Pitch, Roll and Yaw, if you change your GPS location, you’ll get a different set Omega, Phi and Kappa. Personally I don’t see why should Pix4D use earth as the frame of reference instead of horizontal plane. Maybe just to hide the raw information in the pictures. Anyway, know you know how.

A year ago, VLC on iOS was forced to remove its support for AC3 codec. I found almost all my videos on iPad were muted.

Since then, I haven’t bothered to check other options. I don’t mind paying a few dollars but I’ve been using VLC since years on all of my computers and mobile phones. There’s simply no other comparable alternatives that works equally well on Windows, Linux, OS X as well as iOS.

Today, I opened VLC on my iPhone again and noticed that I can play my videos with sound again! I checked the official website for sure and got this:

https://forum.videolan.org/viewtopic.php?f=36&t=124115&sid=c0ad097c62e429e8e5fe5f68aa14fc54&start=20#p441786

The link on iTunes also confirmed this. However, nowhere did I find details how did the developers solved the patent issue. Let’s hope it’s fixed for good.

正在考虑建立一个中国古诗文网站，目的是给孩子看，类似于《唐诗三百首》和《古文观止》，内容也多从其中来。特色在于：

• 在内容上，以原文为本。不要译文，基本没有注释。
• 在布局上，以内容为主，去除一切干扰因素。要求干净，大方。
• 各古诗文名家作者就是blog作者，既直观有趣，又方便组织。

需要做的工作：

1. 开发批量插入作者的功能——已完成；
2. 开发批量插入帖子的功能——已完成；
3. 建立分类目录：需要专业人员帮助。
4. 开发新的数据结构以存储传统计时方式：朝代，年号，年号纪年，公元纪年，季节，时令，时辰。
5. 扩展帖子属性，其中帖子发表时间采用新的数据结构。
6. 扩展作者属性，其中作者生卒时间采用新的数据结构。
7. 修改界面，使帖子能够显示传统计时（年号，天干地支）。

当前状态见这里：http://gushiwen.genglinxiao.com/