M4A files are a type of audio file developed and popularised by Apple. Since 2007, music purchased through the iTunes store has been in m4a format, therefore accounting for over 15 billions files worldwide. MP4 and M4A files are often confused, and the two are quite similar, being both based on the MPEG-4 codec. However, M4A is a file comprising solely of audio, whereas MP4 may also contain video.
Apple Inc. has designed M4A format on the basis of QuickTime Fike. Now the format is being promoted in iTunes. It is a multimedia container intended for placement of sound components, as well as other data, such as images. MPEG-4 files may be stored with extensions M4A and MP4. In the latter case, they contain video as well.
Alongside these sound formats, MPEG-4 allows for lossy compaction, through FFC Codec. However, it is possible to provide a lossless compaction thanks to Apple Lossless format. The files may be played on Windows PCs via iTunes, Windows Media Player 12, KSP Sound Player, Winamp and some other programs. With iTunes, the data can be converted into Windows-supported audio formats.
M4A files are superior to MP3 in terms of the scale of compression and audio quality. The M4A file uses Apple's codec and resides within the MPEG-4 container. The main benefit of M4A is that files are compressed but are lossless. This means they can be decoded back to the original quality they were at the point of compression. Another benefit of M4A files are that do not carry any Digital Rights Management (DRM) protection associated with other files meaning they are less restricted.
In comparison with its predecessor MP3, M4A format provides with better sound quality and smaller file size. Thanks to lossless compaction, the data may be easily converted in both direction with no deterioration in quality. The sound data encoded with ACC compression, which reduces the file size considerably.
Due to protection technology DRM, MP4 files cannot be easily distributed, while it is much simpler to replicate files in M4A; that is why Apple Loversprefer the latter format. With M4A, it is possible to buy music in iTunes, as well as download it into smartphones or other devices.
WAV (WAVE) files are audio files playable via multimedia playback software such as Windows Media Player and other software available for your operating system. These files contain any sounds such as sound effects, music or spoken words. WAV files are large in size and with the advent of MP3 and MP4 WAV files are becoming less popular and less common. They were created and developed by IBM and Microsoft but unlike MP3 and MP4 the WAV file format does not use a form of lossy compression so file sizes are therefore much bigger and now less popular.
WAV format is intended for operation with digitalized audio stream. It contains musical compositions, voice recordings, and various audio effects. Developed by programmers from Microsoft and IBM, it is a key format for placing of uncompressed sound files on Windows PCs. The files can be played back in QuickTime, Windows Media Player, Wav Player and some other programs. In addition to that, they can be processed in audio editing apps.
When a file is compressed into WAV, the data are not supposed to be lost, and the quality is excellent. However, the format did not have a huge market share, due to its larger size, as compared with MP3. It is required to have enough time and disc space to upload and send such files via the Internet. One of the major advantages of WAV is linked to the use of Linear Pulse Code Modulation (LPCM) for storage of audio stream. Consequently, a copy is just as good as an original, which is highly appraised by experts in music and professional users.
Wav files are the standard digital audio format in Windows. Using the .WAV file extension, 8- or 16-bit samples can be taken at rates of 11,025 Hz, 22,050 Hz and 44,100 Hz. The highest quality being th 16-bit at 44,100 HZ, this highest level is the sampling rate of an audio CD and uses 88KB of storage per second. All general sounds in Windows, such as when you log in, are in the .WAV format. The default content of a WAV file is uncompressed (although they can be used to store compressed formats such as MP3), pulse code modulated (PCM) digital samples derived from the analog source.
Sound files with this extension are recorded into 8 or 16 bit per sample. A standard option for CD Audio is an audio stream of 16 bit per sample and sampling frequency of 44.1 KHz. One second of sound corresponds to 88 Kb of internal memory. WAV files can store metadata in the INFO chunk, and they also include integrated IFF lists.
In some cases, the standard format may be used for broadcasting. For instance, BBC stereo data of 44 100 Hz and 16 bit are generally accepted within the VCS system.
Microsoft & IBM