MP4 is a newer file format and supports video encoding, compared with MP3, which is older and is only for audio files. MP4 is a multimedia container and can technically support not just audio and video but also text and images.
edit Origin of MP3 and MP4
MP3 is actually MPEG – 1 Audio Layer 3, an ISO/IEC standard of 1991, is an audio encoding format that uses an algorithm called lossy compression that hugely reduces the data required for the audio recording without disturbing its quality. MP3 was invented by a group of engineers from Europe, belonging to Philips, CCETT (Centre commun d'études de télévision et télécommunications), IRT and Fraunhofer Society working under the EUREKA 147 DAB digital radio research program framework.
MP4 is actually MPEG-4 Part 14, formally ISO/IEC 14496-14:2003, a multimedia container format standard specified as a part of MPEG-4. MP4’s advantage over other formats is its ability to handle digital videos, text images apart from digital audio files and the capability to stream files over the Internet. MP4 is loosely based on Apple's QuickTime MOV format but specifies support to MPEG and related formats.
edit Release of MP3 vs MP4
MP3 was first released for public use on the 7th of July, 1994 by the Fraunhofer Society with an encoder called 13enc. However, the file extension name of .mp3 was introduced only on the 14th of July, 1995 until which MP3 files had the extension .bit. Winplay3, released on the 9th September, 1995 was the first realtime MP3 player which enabled people to record and playback MP3s from their PCs. The low hard disk spaces of those days proved MP3 to be a boon and it was a runaway hit immediately.
MP4 was released for public use in 2002. It can be said that Apple's iPod popularized MP4s more than anything else. But in recent times, the advent of multimedia enabled mobile phone instruments have also had a major hand in popularizing the concept. Google Video used MP4 to allow users to download video to their Apple iPod or Sony PSP which also made MP4 a popular video format. MP4 is also more popular than Apple's Quicktime format (.mov) because it uses less space and can be played using shareware or freeware such as VLC.
edit MP3 vs MP4 - How they work
MP3, being an audio specific format, cannot compress videos. It typically removes sounds in the recording that are outside the normal human hearing range using pulse code modulation, a less space consuming and simple method of modulation and psychoacoustic models. In some ways, what JPEG is to images, MP3 is to audio.
While there are no stringent recommendations by MPEG-1 for MP3 encoders, there are well defined specifications for the decoder algorithms file formats. This has led to a flood of MP3 encoders in the market with very few decoders that are compatible. But the easy availability of comprehensive information enables users to choose the best encoder decoders. In short, MP3 is actually a trade off between the quality of a sound and the amount of space it occupies. To compress a sound file, it is recorded with a lower bit rate leading to deletion of high frequency sounds in the file resulting in a drop in the audio quality. There also exist a few side effects of sound compression like echo, compression artifacts (sounds present, but not a part of original recording), ringing etc. Files with random sounds and sharp attacks are also difficult to compress. Its working is very similar to that of the MP3 and it has been created with mainly the mobile devices in mind. However, though the standard prescribed file extension is .mp4, many companies, in their quest to maintain their individuality, come out with different extensions. A notable example is the .mp4a extension by the Apple Inc. Also, MP4’s abilities to contain audio, video, text images makes it all the more difficult for the decoder to predict the type of streaming of any particular MP4 file.
edit Limitations of MP3 vs MP4
Some of the limitations that dogged the earlier encoders are mentioned below. However, latest formats like the Vorbis AAC are free from these limitations.
- Bit rate is limited to a maximum of 320 kbit/s (while some encoders can create higher bit rates, there is little-to-no support for these higher bit rate MP3s)
- Time resolution can be too low for highly transient signals, may cause some smearing of percussive sounds although this effect is to a great extent limited by the psychoacoustical properties of the Musicam polyphase filterbank (Layer II). Pre-echo is concealed due to the specific time-domain characteristics of the filter.
- Frequency resolution is limited by the small long block window size, decreasing coding efficiency
- No scale factor band for frequencies above 15.5/15.8 kHz
- Joint stereo is done on a frame-to-frame basis
- Encoder/decoder overall delay is not defined, which means lack of official provision for gapless playback. However, some encoders such as LAME can attach additional metadata that will allow players that are aware of it to deliver seamless playback.
edit MP3 Revolution vs. MP4
With the advent of the Internet, on-line music was growing rapidly and better compression techniques were sought after in order to optimize storage. MP2 – MPEG Audio Layer 2 was found on the internet during October 1993 with a playback software called Xing MPEG Audio Player initially and further revisions releases. Soon audio rippers (softwares to copy music from audio CDs and convert them into MPEG formats) appeared. The Internet Underground Music Archive (IUMA), the first internet, high-fidelity, music site popularized these concepts. Players like Winamp by Nullsoft (1997) and portals like Napster (1999) took these concepts to every modern home. Napster, in particular, with the help of MP3s popularized & enabled peer-to-peer music sharing through the internet, resulting in large scale losses for the music companies through huge drops in sales of Audio CDs and this led to a string of law suits being filed against Napster for copyright infringements and Napster eventually had to shut down.
In the past few years, retailers have started using high end encryption methods to stop peer-to-peer sharing, even against the music companies’ recommendations leading to a small drop in peer-to-peer sharing and infringements. But side effects like requirement of a particular player or device, incompatibility and device transfer problems continue to dog the base users.
The advent of MP4 has led to extremely high levels of portability & accessibility. Today, the world watches videos in their car, sitting in aircraft or even on their mobile phones. E-Mail, internet & television are also accessible from all parts of the world – all this with very minimal setup in terms of hardware. 3G enabled mobile phones have the capability of streaming live satellite television. Facilities like mobile office, mobile blogging and GPS have revolutionized the human life.