MPEG is virtually associated with video files on a computer; however, the acronym actually stands for the Mobile Picture Experts Group. This group comprises of researchers from the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). Their first collaboration was in May 1988, and since then they have been meeting every four years, usually in a week at a time.

Members of MPEG have been responsible for continuously developing the standards for digital audio and video (AV) compression and during each meeting a certain compression format is announced and standardized. Since 1988 there have been many ancillary standards developed by MPEG.

MPEG-1 is one of these formats. It comprises of AV encoding and data compression standards set by the MPEG. This format (which came out during the early parts of the 90’s) was developed specifically because the MPEG saw the potentials of compressing video clips to fit in an average CD-ROM. The compression which was involved in the MPEG-1 format decreased the quality of the original video clip to resolutions close to that of a VHS tape.

The fact that MPEG-1 was developed this early has made it the most compatible file format which was developed by MPEG. However, MPEG-1 was limited in the sense that it only supported pictures displayed through progressive scanning, which is only one of many methods used to display motion pictures.

This limitation of MPEG-1 ushered the development of a newer file format, MPEG-2. Besides being able to accommodate other methods used in the transmission of moving images, MPEG developed this format to be used for movies which were digitally transmitted to be shown over cable and satellite television systems. The AV compression involved in MPEG-2 would define how the video clips distributed on more advanced forms of data storage should be formatted.

One of the approaches in video compression for this standard involves the elimination of the repeated display of a pixel deemed as constant in a given period of time. In other words, if a stationary background such as a sky is displayed in numerous frames at a time, then display information of the constant sky is captured on the first frame and simply replicated instead of being rebroadcast as frames progress. The whole process usually ends up with little to no effect on the quality of the moving image.

MPEG thought that a different standard should be developed to handle High-definition Television (HDTV). For this matter, the standard MPEG-3 was developed. It was discovered later on that tweaking the MPEG-2 standard worked just as good to accommodate the signals of HDTV, so the MPEG-3 standard was abandoned. By the way, this standard should not be confused with the famous MP3 audio file format, which is short for MPEG-1 Audio Layer 3.

With the quick progress of technology, there have been more and more powerful decoding hardware available in the consumer market. Demands for video from other sources have also been defined, and for this matter the MPEG came up with the MPEG-4 standard. This standard was developed for the purpose of compressing digital AV Data, and therefore it is critical in the transmission of media through the internet. Examples include streaming video, and videophone conversations. Besides integrating MPEG-1 and MPEG-2 features, this standard also incorporates other functions for more advanced display techniques, including 3D rendering. Since illegal downloading has been a concern for many producing companies, there have been many approaches to ensuring that modern video files grant exclusive access to people who have say, purchased a movie. One of these approaches is called Digital Rights management, and it has also been incorporated with the MPEG-4 Standard.

As of today, MPEG-4 is still a work in progress based on the many more demands for video now than ever, and the whole standard has its own standards under it. MPEG-4 Part 2 is one of these video compression standards. MPEG-4 Part 2 has as much as 21 grouped features to accommodate all applications from the simple video camera to the high-quality DVD.

MPEG has also joined with the International Telecommunication Union’s Standardization Sector (ITU-T) to develop the MPEG-4 Part 10 standard. MPEG-4 Part 10 is being developed for the purpose of maintaining good video quality and design simplicity while lowering bit rates substantially. This is being developed not only to accommodate the video demands of the present times but the upcoming devices and upgrades in the future. Both MPEG and ITU-T have finished the drafts for the initial standard to be rolled out last May 2003. These entities have been working hard ever since to finalize all details regarding this lucrative standard.

It is just fortunate that groups like MPEG exist to ensure that the proper standards are developed for the speedy and highest quality displays and transmissions of video clips. The members of this esteemed group are definitely recognized for their accomplishments which started nearly two decades ago.

The MP3 is known to be one of the most popular audio file formats known to most people around the civilized world today. However, many people may not realize it, but they also may be using audio files with the AMR file format for a good number of times too. If you find yourself buying a cell phone model which came out at least 2 years ago, chances are it will probably have a voice recorder integrated with it. When you copy these recordings onto your computer, you will find out that these files have .amr file extension.

AMR stands for Adaptive Multi-Rate, and it is named for the philosophy behind it. There are unique data constraints which are defined by the compression scheme which makes audio files. These constraints are integral to the principle that as interference from the audio source increases, codec rates are lowered to allow more effective application of error correction. It is for this matter that AMR audio file players and encoders have a good range of data rates for the overall scheme to adjust to.

AMR is used primarily in speech coding, and it also incorporates data compression to ensure that more .amr files can be saved in a single device. When an AMR file is played, one will not necessarily notice a considerable variance in audio quality. Of course, this is considering if the original source is of good quality, and there are no significant noise interferences in the background. It is also possible to record music to be saved in AMR file, however the chances of the audio quality being top quality are slim.

The AMR file format is best known for applications and other features integrated in modern cellular phones. These programs range from simple audio player/recorders to programs linked to VoIP (Voice over Internet Protocol) technology.

There have been other file formats used by cell phones prior to the introduction of AMR, such as the EFR or Enhanced Full-Rate codec. AMR’s flexibility to adjust its bit rate depending on the quality of the audio source makes it stand out among these other alternatives. Additionally, the features involved in the AMR format make the resultant file intricate in all considerable aspects.

First, there is VAD, or Voice Activity Detection. This AMR feature simply differentiates instances of speech from instances of silence coming from an audio source. There are times where the AMR file format utilizes VAD to improve the quality of the speech recording. Depending on the properties set on a particular cell phone or program, AMR can use VAD to stop recording during dead air to save space and to shave time off the length of the file.

There’s also CNG, short for Comfort Noise Generation. As the name implies, this feature introduces background static in a very low and tolerable level. Why would adding static while recording a good thing? It minimizes a considerable number of bad effects derived from absolute silence. For one, it keeps the codec rates in a decent level, in preparation for the possibility of disruption from sudden increases in volume. It also gives the person on both sides of the line the assurance that the phone connection is still active, keeping either one of them from hanging up during instances of dead air.

Discontinuous Transmission (DTX) is a feature used particularly in mobile devices with AMR audio file format capabilities. This feature saves power by controlling the device’s transmitter switch to make sure that the battery and amplifiers are not used during those instances of dead air during wireless conversations. It would mute a mobile phone when there is no voice input being made.

These three features of AMR are used together for the main purpose of reducing the usage of precious bandwidth during periods of silence.

Finally, there’s ACELP, which is short for Algebraic Code Excited Linear Prediction. AMR makes use of this sub-algorithm in integral parts of encoding, specifically during times when codec rates are adjusted to ensure continuous recording despite audio interference. As the name implies, it is a set of computation which determine the next best codec rate for the AMR encoder to adjust, where the audio source shows an abrupt change in volume or interference.

What does all of this mean? It simply implies that files of AMR format may be underestimated in terms of audio quality, but its features still make it the premier file format when it comes to recording conversations and other forms of speech from a cell phone. Almost all recordings which come from mobile devices may be converted to audio file formats of better quality, but they have to go through the basic process of AMR formatting first.

When it comes to audio files, the WAV file format used to stand out during its time. This particular audio file type has been a standard ever since Windows 95 came out. With a vast number of operating systems coming out since then, WAV has become one of the most recognized audio file formats. Almost all of the conventional programs we have today are able to support WAV.

Files with the WAV file format are known as one of the simplest out of the many formats when it comes to storing audio tracks. It is considered a direct transcription of sound to data, with mere formatting being the only pre-processing required. Unlike compressed formats such as MPEG, a WAV file consists of only three parts, three “chunks” of information. The purposes of these chunks are very basic: There’s the RIFF chunk which basically tells the computer that it is dealing with a WAV file. There’s the FORMAT chunk which contains sample rate data, besides other information pertinent to the details of the audio track. Finally, there’s the DATA chunk, which is where the actual audio sample is contained. The WAV file format is not necessarily complicated, which is why files with .wav extensions are bigger than usual.

Many people have also known audio files with the .wav extension for their large size. This is due to the high audio quality capabilities of the file. It is for this reason that it is used for audio CDs. Sound tracks are recorded and saved in the .wav file format, and then these files will be manipulated and encoded in Pulse-code Modulation (PCM) into precise locations or sectors in a conventional blank CD. A common music track of the WAV file format which is around 4 minutes long can take around 50MB of space, and a normal CD can store up to 600-700MB of data. This is why many audio CDs have an average of 13-15 tracks.

Files with the .wav extension have become less and less popular as internet file sharing was recognized and utilized by more and more people. Files which are bigger naturally take longer to upload or download, which is bad for people who frequent the internet looking for music. In this field, other file formats which take less memory to store and less time to transfer are definitely more popular. Files with the MP3, AAC, and WMA extensions are good examples of these formats.

Many people have also been known to encode their audio CDs with WAV quality tracks to MP3 files to add to their own libraries. Methods such as compression reduce the quality of Audio CD tracks converted to MP3 files. When these MP3 files are “burned”, or converted back into Audio CD tracks, many people do not notice or ignore the effects of quality reduction. This is an example of how a majority of enthusiasts are usually satisfied with what they hear and download the first time, as long as the tracks they have take less memory space to store.

If there are so many other formats which take less space and less time to acquire, then why is the .wav file still being given attention? WAV files are suitable for systems which prioritize sound quality over disk space. Software developers who are looking to make sound an integral promoter of their products usually make use of high-quality audio in the form of .wav files. For example, programmers in the field of gaming usually use WAV files for sound effects. Multimedia designers also prefer using audio files with the .wav extension for creating their own video and sound clips. Radio broadcasters who want to eliminate the cost of recording and storing tracks in tapes resort to saving their audio in WAV files. This way, the audio quality of their recordings is preserved.

The audio in a file with the .wav extension is also relatively easier to edit and manipulate, due to the simplicity of the file format’s structure. The audio track of a WAV file can easily be truncated or edited to add and remove extra effects. There are many third-party WAV editors available in the internet for this purpose.

It is the simplicity of the WAV file which still makes it a desirable file format in a good number of industries. There’s the fact that it is still recognized and supported by a majority of popular audio programs and operating systems which makes it a winner. The audio quality of the tracks a WAV file contains is one advantage it has over other file formats. Additionally, files with the .wav extension have a very basic structure which provides easy access to the actual audio track for quick customization and adjustments.

The WAV file is a good example of how quality is prioritized over quantity. They are literally bigger and better.

Napster and iPod. One was a controversial file sharing program which was integral to early online audio enthusiasm, and the other was a revolutionary gadget instrumental in promoting digital audio appreciation to the public. A majority of the files downloaded from Napster were of the MP3 file format. Most of the files copied into the iPod are also of the MP3 file format.

What is MP3? It is actually a file extension, and it stands for ‘MPEG, Audio Layer 3’. It is an audio encoding format which makes use of an algorithm, or a specific set of instructions, to significantly compress the size required for a high quality digital audio file. This sort of compression involves the removal of certain sections and wavelengths which are beyond a person’s hearing range. The resultant file has a smaller size and its audio quality can be considered identical to the source it was derived from. This combination of convenient storage requirements and nearly indistinguishable audio quality has made it a hit among many audiophiles.

Not many people know that the concept behind what we now know as the MP3 file format were already being developed back in the 1980’s. Professors and engineers from places ranging from Argentina to Germany made significant contributions to the method of creating or converting sound samples to MP3 files. This method became known as the MP3 Algorithm. Back in the early 1990’s the MP3 algorithm was known to be tested on a song by Suzanne Vega, entitled ‘Tom’s Diner.’ This song stood out among other audio samples used to test the effectiveness and efficiency of the MP3 algorithm and was informally named the ‘Mother of MP3s’. The algorithm was eventually finalized, and on July 7, 1994, the first MP3 encoder for the PC was released.

The options for playing music prior to the MP3 were quite limited. People used to resort to cassette tapes and audio CDs. If a person had a computer back then, he or she usually was not so enthusiastic in keeping 40MB of WAV files.

Nearly a year after, MP3 files were known to circulate on the internet. Songs converted to the MP3 format grew more and more popular as software MP3 players was made available to the public via download from the internet. Not many people had broadband internet back then, but those who had a connection to the internet were definitely more excited in acquiring quality music file as small as 4MB in MP3 form, instead of 40mb in WAV form.

An early and still popular example of audio players supporting the MP3 format is Winamp. Other algorithms have been developed to produce similar file formats such as WMA and OGG, but it is the MP3 file format which was in the minds of many who were seeking music at the time. Encoders were developed to derive MP3 files from audio CD tracks, a method more popularly known as ‘ripping’.

Audio players were eventually followed by P2P programs which supported the easier sharing of files over the internet. ‘Ripped’ MP3 files served as the majority of audio tracks exchanged this way due to its small file size. One of the most popular programs of this type was the previously mentioned P2P program Napster. It was Napster which was targeted by lawsuits coming from a good number of record companies who, at the time, experienced a considerable loss of revenue due to this phenomenon of free music sharing.

MP3s have revolutionized the way people obtain music. The number of people who prefer to download music instead of purchasing them in record stores has grown significantly. It is for this reason that portable MP3 players were developed. ‘Walkman’ devices with MP3 storage and playback capabilities have been in the market since as early as 1998. Sales for MP3 players were quite mediocre, prior to the release of the Apple iPod, the portable music gadget which was a surprise hit for a great number of people. Its simple design, reliability, and capabilities have made it a must have even for people who were not necessarily computer enthusiasts.

In the light of these two extremely noteworthy events in the unpredictable world of technology, it would be difficult to tell how the world would be without the MP3. Who would have known that the development of the MP3 would have such an integral effect on the world in the fields of entertainment and economy?