In the era of technology, we have to deal with a huge bunch of data every day. That makes the data storage become more significant. Optical disc is the most widely use storage. Among the optical disc storages VCD and DVD are the most popular. These two have the same shape and the same size but, of course, there are some differences. This article will discuss about three differences of VCD and DVD, which are price, capacity, and quality.
The price is a major concern for people who want to buy the disc storage. The price of VCD and DVD is according to the brand of the disc, the place you buy and the amount of discs you buy at a time. VCD or DVD of Sony or Phillips may have ten times higher price when compared to the local brand like Princo or EasyWrite. Besides, if you buy them at a department store, they are more expensive than buying at an IT shop such as Pantip Plaza. Moreover, buying a bunch of discs at a time is cheaper than buying two or three discs. The shops provide a box of fifty discs for selling and if you preferred just a disc, no box, they will give you some discount! However, those are the similarities of the price of VCD and DVD, but if we compare between VCD and DVD which have the same brand and sold at the same shop, the price per disc of VCD is much lower. In Thailand, Princo VCD’s price is about 4 baht per disc but the Princo DVD’s price is 9 baht per disc. Even though 9 baht is not expensive at all but if you buy DVDs a lot, it can be a big amount of money.
Capacity is another difference between VCD and DVD. At the beginning, VCD can store up to 800 MB of data per disc while DVD can store up to 4.7 GB of data per disc (1 GB is about 1000 MB). As time goes by VCD still has only one type which capacity is about 800 MB as I mentioned, by contrast, DVD has developed up to three types, single-sided single-layer, single-sided double-layer, and double-sided double-layer. These three types of DVDs can store up to 4.7 GB, 8.5 GB, and 17 GB of data respectively. Anyway, in term of capacity, DVD has bigger space to store the data.
Furthermore, another difference to be considered is quality. If we compare a media disc such as song or movie disc, DVD has much better quality. Physically, it has clearer pictures and better sound because DVD has more bit rate than VCD. Moreover, DVD seems to have a longer life and more difficult to break. On the other hand, if we focus on just a data file such as a document file or power point, VCD and DVD represent an equal quality. However, the movie that is on VCD and DVD is not so differ, not many people realize that difference.
In conclusion, even though VCD has lower price, it has a smaller market share while DVD has the biggest market share of optical disc storage. That is because the price of DVD is not so high and it has much higher quality and capacity. Anyway, in my opinion, it is okay if you use VCD for a data file or anything except media data like songs or video clips. In the case of media data, I prefer DVD.
First, the audio file that has the highest quality is the uncompressed file. It keeps almost every details of the sound and it is nearest to real sound. The sounds in the CD also use this format. This uncompressed audio file contains every signal of sound wave even the sound that humans cannot hear. The example of this kind of file is WAV file, which is compatible with Windows, for Macintosh is AIFF. Anyway, to keep every detail of the sound, it needs a huge space. The uncompressed audio file is the biggest audio file, a file of three to four minutes can be more than 30 Mb.
Second, the medium quality audio file is the lossless compression file. The lossless compression allows the exact original data to be reconstructed from the compressed data. This technique also used with other applications such as ZIP file and PNG image. This kind of audio file is not different so much from the uncompressed file. If we compare by hearing directly, it is so hard to distinguish between these two files. The example of the lossless file is Apple Lossless or ALAC. The Apple Lossless was introduced on April 28, 2004 as a feature of iTunes 4.5 and QuickTime 6.5.1. However, the lossless file is very difficult to implement, so it is not so popular in Windows. Nevertheless, we usually use the lossless compression technique with the text file more than the audio file or media file.
Third is the lossy compression file. It is the lowest quality of the audio file but it is the most popular format. The lossy compression audio files discard the range of signal that humans cannot hear even the vague range of signal. In fact, this technique discards all details that humans cannot perceive. MP3 is the example of this type of audio file. It is the most popular audio format today because its size is quite small, three to four minutes song is just about 5 Mb. Anyway, even though the lossy audio file has the lowest quality and we can see or hear the differences between lossy file and uncompressed file clearly, that low quality is acceptable. Moreover, this type of file is commonly used in streaming media because its size is small; it is convenient to transfer the file.
In addition, uncompressed, lossless compressing, and lossy compressing are the techniques that are used to handle the data, not only the audio but also all of types of the data. These three techniques give different qualities. You can choose which good quality you like when you save the file by adding the file extension after a filename.
The first example is CAT 009 which is the VoIP service for landline telephone provided by CAT Telecom, a Thai telecommunication company. In Thailand, CAT telecom has the biggest market share of international telecommunication because of the implementation of VoIP technology. CAT 009 has 44 percent of international telecommunication generated from Thailand. If we focus on the international VoIP service, CAT 009 has up to 77 percent of market share (Sewu-cat.com). Moreover, I interviewed some friends about their experiences of international call; they said that the international VoIP is better than using the traditional telephone. International VoIP cause less delay and less losing of voices during the communication. That is why CAT 009 is so popular in Thailand.
Another example is 0033 international Mobile-Plan, the VoIP service for mobile phone offered by Nippon Telegraph and Telephone Corporation or NTT. It is a Japanese company, which dominates the telecommunication market in Japan. NTT is the largest telecommunication company in Asia and the second largest in the world (Wikipedia.com). For the international call, the differences of time cause a lot of inconvenience especially the delay and the additional charge. Anyway, 0033 allows you to make an international call from your mobile phone at a flat rate regardless when you call at night or in the morning (506506.ntt.com). However, I really do not know how effective it is because I have never tried it yet and I do not know anyone who ever try 0033 of NTT.
The third example is an application that helps users communicate via the internet by using their computers known as Skype. Skype allow users to make a call over the internet, not necessarily an international call, and it is free! There are a few people who know that Skype implement the VoIP technique because it looks very similar to an instant message application. Nevertheless, Skype is quite popular among teenagers and middle age people because it is free. Besides, Skype has some interesting additional features such as file transfer and video conferencing. Lastly, Skype is very easy to use if you just want to try!
In conclusion, VoIP is a new technology that makes telecommunication more effective. Today, there are many VoIP services and applications. CAT 009, 0033 Mobile-Plan, and Skype are the examples of VoIP services and applications which we are quite familiar with. Up to this point, I hope this article has made you more interested in this new technology. The more you know about it, the more effective it will be!
