Watching Webcasts on a Mac
There's no other major item most of us own that is as confusing, unpredictable and unreliable as our personal computers. Everybody has questions about them, and we aim to help.
Here are a few questions about computers I've received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about watching Major League Baseball's streaming Webcasts of games, the capacity of digital music players and the security of Wi-Fi.
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Q: I just bought a new Mac and I love it, but I am a die-hard Yankees fan and I find that, with the Mac, I can't watch Major League Baseball's streaming Webcasts of games. Is there a way around this?
A: Since I am a huge Red Sox fan, I hesitate to help you ... but I will.
It doesn't work, because MLB.com this year switched to a Microsoft video format that the Mac version of Windows Media Player can't handle and it doesn't support the Safari Web browser that Apple includes on every Mac. There is a workaround: download and use Firefox, instead of Safari; and download and install Flip4Mac, a free program that allows QuickTime to handle the newest Windows Media video format. You can get it at:
http://flip4mac.com/.But even this solution is seriously flawed. The problem -- and the Flip4Mac people are working on it -- is that it plays only for a few batters or so, and then you have to restart it by relaunching the TV feed in the Web site. This is a pain, but it does work, sort of.
A better solution is to simply run Windows on your Mac, and then play the MLB videos on that. I do this using a product called Parallels desktop, which runs Windows inside a window on your Mac. It's available at:
www.parallels.com.Q: I am not clear about capacity on digital music players. As far as I can determine, most music CDs run to about 600-700 MB, so a mere 10 CDs would fill most of a 10-gigabyte iPod, correct? On the other hand, I recently read that all of Mozart's works would fit on a 10-GB iPod. So what's wrong with my calculations?
A: When companies calculate the capacity of digital music players in terms of songs or CDs, they base their calculations on the use of music files that have been drastically shrunk from their original size on a CD. This is done by converting the songs to compressed file formats, including the MP3, WMA, or AAC formats. This is what happens when you import, or "rip," a CD into iTunes or Windows Media Player on your computer in preparation for loading the songs onto a portable player.
A typical MP3 file compresses CD music by a factor of 10 or more. So, a 650-megabyte CD might take up just 60-65 megabytes on a computer or a portable player. There is a price to this compression: The quality of the music file is degraded. However, most people find the quality acceptable, especially with common types of music -- pop, rock, country and hip-hop.
Many audiophiles and classical-music fans choose to compress their CDs less drastically, seeking a balance between space-saving and quality. This can be achieved by changing the settings in your music software. Others opt for no compression at all, though, as you noted, that severely limits how much music you can squeeze onto a portable player.
Q: I would like to link up the computers in my home wirelessly but am apprehensive about the security aspects. Is it safe to use Wi-Fi?
A: Yes, in almost all cases. Wi-Fi networks come with an optional security feature that requires anyone using them to know your password. So, you can turn that on. Even if you don't, your files would be at risk only if you had a neighbor close enough to access the network who is both skilled enough and nasty enough to want to poke around in your files. In most neighborhoods, that combination is pretty rare, as is the likelihood that hackers will drive down your street in a van with a laptop and steal your secrets.
However, I would also maintain a software firewall and turn off all file-sharing features of your operating system and other software.
There are exceptions. If you live in a large apartment building, the number of potential snoopers who are strangers goes way up, since many more people will be close enough to access your network than they would be in a suburban neighborhood of single-family homes. Also, no security system is perfect. Determined hackers could theoretically break into any wireless network.
But, in most scenarios, I believe Wi-Fi is safe.
Wi-Fi安全否？
在我们大多数人拥有的大件电器中，再没有什么比个人电脑更令人费解、更变幻莫测的了。每个人或许都有些关于电脑的问题，而《莫博士信箱》将为您提供帮助。
本周我将回答读者有关音乐播放器的容量计算以及Wi-Fi安全性等问题。
问：我不太清楚数码音乐播放器的容量问题。据我所知，大多数音乐CD盘的容量是600-700兆，那么10张CD盘上的音乐就会占据一个10G iPod的大部分空间，对吗？可是，我最近看到一些文章说莫扎特的所有音乐作品都可以被装入一个10G的iPod中。那么，我的计算有什么问题吗？
答：当商家用歌曲数量或CD盘数目来衡量数码音乐播放器的容量时，他们是以较CD盘上原始大小大幅缩水后的音乐文件的数量为计算基础的。这些音乐文件被转换成MP3、WMA以及AAC等压缩文件格式后其大小就会大幅下降。其时当你把CD盘上的音乐输入或“剥离”到电脑中的iTunes或者Windows媒体播放器软件中，准备把它们存入便携式音乐播放器时，就是音乐文件被压缩的过程。
CD盘上的音乐文件被压缩成MP3文件后其大小最多只及原来的十分之一。也就是说，一张650兆的CD或许仅占据电脑或便携式音乐播放器中60-65兆的存储容量。当然压缩也有代价：音乐质量会下降。不过，大多数人都能够接受压缩后的音乐质量，流行、摇滚、乡村以及嬉哈等大众型音乐尤其不存在问题。
很多高保真音乐发烧友以及古典音乐爱好者选择小幅度压缩CD盘上的音乐文件，以求在节省空间与确保音乐质量间达成平衡。这可以通过改变音乐软件的设置来实现。还有人选择根本不进行压缩，不过，正如你提到的，这样做极大地限制了你能够“塞入”便携式音乐播放器中音乐的数量。
问：我想把家里的电脑进行无线连接，但是又非常担心网络安全问题。使用Wi-Fi安全吗？
答：大多数情况下是安全的。Wi-Fi网络有一个可以选择的安全功能，这个功能会要求任何使用这个网络的人输入你的密码。你可以启动这个功能。不过，即使你不启动它，只有在非常特殊的情况下你的文件才会面临危险：你的邻居离你足够近，以至于他能够进入你的Wi-Fi网络，同时他具有熟练的技术、且卑鄙到要破坏你的文件。但在大多数社区中，要同时凑足这几个条件是相当不容易的。而且出现这种情况的几率与黑客驾车行驶在你门口的街道上用笔记本电脑窃取你的秘密的几率相差无几。
不过，我还是建议你安装防火墙，并关闭操作系统以及其他软件中的文件共享功能。
当然也有例外。如果你住在一座大型公寓楼内，那些潜在的陌生窥探者的数量会直线上升。在这样的环境中，近到能够进入你的网络的人数要比在郊区单户住宅区中的人数高很多。不过，没有绝对完美的安全系统。从理论上来讲，下定决心的黑客能够闯入任何无线网络。
但是，在多数情况下，我认为Wi-Fi是安全的。
