File extension | .m4r |
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File category | Audio |
Stands for | MPEG-4 PART 14 for iPhone ringtones |
Developer | Apple Inc. |
Overview | M4R is one of the extensions of MPEG-4 Part-14 and it is specially designed by Apple for iPhone ringtones. It is just the relabelling of AAC and M4A. This extension provides an excellent quality of ringtones for iPhones and the size of the ringtone is also small. There are certain steps that one needs to follow for the conversion of any song into this format (iPhone ringtone). Firstly, select any song of 30 seconds and covert it to AAC format using iTunes. Then rename this file using .m4r extension. Finally, by using the iTunes transfer your ringtone file to iPhone. This can be done by connecting your iPhone to the computer and syncing the playlist. Now a user can easily use this ringtone for phone ring, alerts, alarms etc. It should be noted that these files will be supported only by the latest version. Hence, use the current version of iTunes. |
Technical description | It uses a lossy compression algorithm to encode the ringtones that is same as AAC and MP3 eareensions. But it has the additional feature of auditory masking which means it neglects other sounds which can be detected or recognized while listening or hearing another sound. It only discards the information which is surplus for the human ear. This results in good quality of iPhone ringtones. It takes less storage space without affecting the quality of audio. It is also a segment of MPEG-4 standard and this is stated in the ISO-IEC standard 14495-3. |
Links | wikipedia.org (opens in new tab - official documentation) |
File extension | .mp4 |
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File category | Video |
Stands for | MPEG-4 Video stream |
Developer | Moving Picture Experts Group |
Overview | It stores multimedia data. It is commonly used by manufacturers (those produce mobile products) as well as by Apple for audio, video and still images. It offers higher flexibility and is compatible with both audio and video files. The Format provided by these files i.e MPEG-4 is commonly used online for streaming the videos. Any Movie, video or Audio file can be easily downloaded or streamed online with this extension which can be free or chargeable as well, such as downloading from iTunes. The payment can be made using credit or debit cards. These files may also include audio books, photos, podcasts, songs, movies, not making them limited to just audios and videos. This format has become more common as they are being used in iPod and PlayStation Portable(PSP). Commonly portable media players are advertised as βMP4 playersβ although they are capable of playing other media format as well like βAMV format'. |
Technical description | MPEG-4 files are officially named under extension .mp4 and this is the only official extension for MPEG-4 PART-14 formats. These files were introduced in 2001 under the standards of ISO/IEX 14496-1:2001. It runs on AAC encoding which restricts the users from copying the data of the files. The data embedding can be done on these files using any private stream. For instance, hint tracks to add the streaming information into the file. These files are similar to most of the modern containers containing data information which allows internet streaming. |
Links | wikipedia.org (opens in new tab - official documentation) |