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 | .mkv |
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File category | Video |
Stands for | Matroska Multimedia Container |
Developer | Steve Lhomme |
Overview | An unlimited amount of data such as an infinite number of audios, videos, pictures, arbitrary files like XML and subtitle tracks can be stored in MKV files. Although, it has a similar concept that of AVI, MP4; etc., yet, there is one difference. It is an open-source software or has open specifications, whereas, others are different. Furthermore, it allows online streaming and fast seeking which are alluring features. It can be used with ease as it is highly adaptive and can accept any audio and video. |
Technical description | Files in MKV format store each track in varied dataline. Files in this format use distinctive extensions for storing the data. The extension .MKV is used only for video files(may have subtitles and audio),.MK3D for stereoscopic video, .MKA and .MKS for audio and subtitles respectively. The codecs that are linked to this format are .SRT, Vobsub, .USF(Universal Subtitle Format) and .SSA; etc. It should be noted that not all the media players support this file format but only selective ones like VLC. Besides this, ‘Matroska' is derived from a Russian word that is ‘Matryoshka’ and it refers to a hollow Russian doll which opens to uncover another doll, this doll then again opens to reveal next doll and the process goes on. Other meanings for this word in Russia are a sailor suit and a female sailor. Technical details in depth are available only for private and commercial use. |
Links | wikipedia.org (opens in new tab - official documentation) |