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 | .flv |
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File category | Video |
Stands for | Flash Video |
Developer | Adobe Systems (initially developed by Macromedia) |
Overview | It is a multimedia container file format which is used over the internet to provide digital video content to the users. Digital video content includes TV shows or series, movies; etc. Adobe Flash Player 6 and new versions provide support to it. To play flash video from Personal Computer and online websites we need an FLV player. Although, Apple iOS does not support Flash, yet, with the help of additional software, one can play flash videos. Also, it is a common platform for various websites that allows video streaming such as YouTube, Yahoo! Video, Metacafe, Hulu; etc . With the help of screen capturing and other recording programs, screen recording is possible for flash videos. Furthermore, it also supports a screen share or screen cast. |
Technical description | FLV files mostly have video bitstreams which are one of the variants of H.263 Standard and it is named as Sorenson park(FourCC FLV1). The SWF files and this extension uses the identical way to encode data. There are two variants available for screen casting. First one is lossy as it reduces colour depth or bit depth (number of bits used to indicate the colour of one pixel) and compresses the data. The second type is only compatible with Flash Player 8 and the newer versions. Both these aforesaid kinds are based on bitmap tile. Uncompressed Audio or ADPCM format audio is also supported by it. This format has header and packets in its video structure. A standard header includes signature, version, flags and header size. |
Links | wikipedia.org (opens in new tab - official documentation) |