Due to the large size of audio files (particularly digital audio files), reducing the file size is almost a necessity. This can be done in two ways, down sampling where you reduce the sampling rate of the digital audio, or by compressing the audio. One of the most common compression algorithms for audio is MPEG (the same that compresses video). This means that when you compress a video clip, you are not only compressing the graphical data but also the audio data. MP3 refers to MPEG Level 3 and is a means of compressing audio to CD-quality at a tenth of the file size. Copyright It is very tempting to sample your favourite pop song and include it in your presentation. Similarly you may find audio clips like “Beam me up, Scotty” in audio collections. Both of these are copyright items and cannot be used without the owner’s permission. If you are in doubt create your own audio clips or use copyright free audio clips. Download MP3 files of the following:
Answer the following questions in your jotter. 1. An audio clip lasting 1 minute was captured with a sampling frequency of 44 KHz and a sampling resolution of 16-bit. Unfortunately it takes up 10.4 megabytes of storage space. Discuss three different ways in which the hard disc space taken up by the audio clip could be reduced. 2. What copyright issues have been examined by the legal cases involving Napster, AudioGalaxy and other file sharing programs? 3. What may be an alternative way to buy music in the future? |
