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 | .3g2 |
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File category | Video |
Stands for | 3GPP2 (An extended form of MPEG-4 Part 12) |
Developer | 3rd Generation Partnership Project 2 |
Overview | The 3G2 format is an upgraded version of .3GP file and it functions to save both audio and video files in 3G phones which are based on CDMA (Code Division multiple access). By using this format, we can transfer files over the internet and can store videos on mobile phones. It consumes less storage space when compared to the 3GP file. Therefore, it helps to save the disk space. Also, this format is very good for mobile streaming and downloading as it supports bandwidth, which is easily compatible with 3G cell phones. Moreover, this is both ISO Base media file format MPEG-4 Part 12 and MP4 file format MPEG-4 Part 14. We can use various software to open these files. For example, Appleβs free QuickTime, VLC Media player; etc. |
Technical description | It is a parallel format of MPEG-4 Part 14 or MP4 but a simplified version, not the complex one. This is the perfect format for 3G cell phones to store videos as low bandwidth is required and besides this, it takes less space to store videos. 3GPP2 can store similar video and audio streams as of 3GP and some additional streams as well. For instance- AMR-NB, AMR-WB, AMR-WB+, AAC-LC, HE-AAC v1, and HE-AAC v2. In addition to these aforesaid streams, EVR-C, EVRC-B, EVRC-WB, VMR-WB are other extra streams used in this format. MPEG-4 media is stored in 3G2 format using MP4 and AVC file format specifications. |
Links | wikipedia.org (opens in new tab - official documentation) |