I like to play basketball since I was a high school student and I still play around one to twice a week now. Although I love this sport, I do not have too much passion to see the games like NBA after MJ retired. In past year, I started to pay attention on it. One reason is Jeremy Lin and the other is the CEO of my company bought Memphis Grizzlies last year. I start to realize this is not just only a game but also contain a lot of things in it. ...
I saw a news that about the Vuzix Smart Glasses M100 and it get a recipient of the CES (Consumer Electronics Show) Innovations 2013 Design and Engineering Award BEST OF INNOVATIONS, and selected as Best Technology in the Wireless Handset Accessory category. More information in following link. http://www.vuzix.com/consumer/products_browse.html#video-eyewear It’s an interesting device but there are still challenges behind. Since Google launch their project glass, Vuzix is the 2nd company to make the similar product. So M100 get a lot of discussion even google guys go their booth to have it a look. According to the hardware specification from Vuzix web sites. It’s totally an android based smart phone and the difference is the glasses appearance only. It’s not special by just hardware specification only. ...
Before the Chinese Lunar New Year, I got the latest alpha version of the AirVision2. It does not only inherit the pros from previous version but more quick and stable also. I just have some preview here about the installation and main pages showing. After double clicking the windows installer, following the step of installation. When executing the airVision2, there is a windows security information pop up, please make sure the firewall does not block your application. ...
Weeks ago, the supplier demo the Miracast function to us and my colleague told me maybe we can think if there are applications for surveillance system. At first I saw nothing special for surveillance application but I may find there is now. Here is a capture picture from the whitepaper of WiFi alliance. Basically, Miracast is a protocol and this means Miracast can be over any kind of infrastructure. However, Miracast connections are expected to be predominantly established between Wi-Fi devices connected with each other directly, without an AP acting as an intermediary. According to the topology, what we can see is a source to a sink and it is a peer-to-peer connection. Go back to the topic we want to talk for surveillance. I plot a picture as follow, and this is just like a traditional surveillance system with cameras, recorder and monitor. ...
The pure public cloud is no doubt that we build the web services on public and the hybrid combine the private part. According to the information on wiki, the public cloud aka external cloud is related to the service is provided by third party. There is a picture on wiki can describe exactly what we talk about. Basically, there are four deployment models on wiki. The private cloud can’t satisfy the requirements of the surveillance system. We do not talk about the community cloud also because it’s not real on surveillance system. There is a famous network camera company named Dropcam that deployment as pure public cloud system. When we install the the devices, we have to create an account and register them. As I know, Dropcam use the Amazon Web Service as the infrastructure. I just plot some simple block diagrams to describe it. ...
純公有雲 (Public Cloud) 毫無疑問是在大眾網路上建構服務，而混合雲 (Hybrid Cloud) 則結合了私有雲 (Private) 部分。根據維基百科的說明，公有雲又稱「外部雲」，是指由第三方提供的服務。維基百科上的圖示能精準地描述我們所談論的概念。 ...
Today is the end of the Dragon year and we use to have a good supper on this day. It’s brand new lunar year tomorrow and we call it Snake year. Sometimes, we’d call it Small Dragon year rather than Snake year because because Dragon is much more significant in traditional. Hope my family and friends have a brand new good Small Dragon Year.
My colleague did some experiments on gstreamer alsasrc and osssrc plugins and he found that alsasrc consume lots of cpu resource(around 16% on the chip we use). He asked me why the test tool that provided from chip vendor is quite efficient(around 1~2%). It was a big gap to me and I started to find why is that. After hours checking, I found that the plugin may cause a busy wait in a while loop when the parameters set to non-blocking mode. I do a simple code modification and execute again but the cpu rate just lower to 12%. I’m a little frustrated about it but still had some enhancement. So I started to try different parameters combination because he told that he found three differences from alsasrc plugin and the test code. 1. The setting of alsasrc is non-block mode but the test code is set to block mode. 2. The channels setting of alsasrc is 1 but the test code is set to 2. 3. The buffer size is limit in test code but alsasrc do not have that limit. For 1: I thought the non-block mode should be much more efficient but the busy wait should change. For 2: This is really weird because when I set the channels to be 2 in alsasrc plugin, the cpu rate become quite low. So I start to wondering if this is the characteristics of the I2S bus. I googled on the internet but did not find any information to describe that we have to set the channels parameter to be 2 in alsasrc plugin of gstreamer when the audio data bus is I2S. So I’ll confirm it later. For 3: I think it’s reasonable to limit the buffer size.
我的一位同事在測試 GStreamer 的 alsasrc 與 osssrc 插件時發現，alsasrc 消耗了相當驚人的 CPU 資源（在我們使用的晶片上約占 16%）。他詢問我，為何晶片供應商提供的測試工具卻能維持極高的效率（約僅占 1~2%）。這巨大的效能差距引起了我的好奇，我決定深入研究原因。 ...
RabbitMQ setup and test Server side: My desktop PC is windows 7 and we download the rabbitmq server from http://www.rabbitmq.com/. The installation guide is here http://www.rabbitmq.com/install-windows.html. I use extra ethernet card and set the ip address to be 192.168.1.19 and make sure the firewall would not block the port 5672. Client side: we put the send and listen on same device. I use the package from https://github.com/alanxz/rabbitmq-c. We can follow the guide in the link to cross build and install on the embedded device we use. ...