of two different file extensions for naming audio-only MP4 files has been a
source of confusion among users and multimedia playback software. Since
MPEG-4 Part 14 is a container format, MPEG-4 files may contain any number of
audio, video, and even subtitle streams, making it impossible to determine
the type of streams in an MPEG-4 file based on its filename extension alone.
In response, Apple Inc. started using and popularizing the M4A format file
extension. Software capable of audio/video playback should recognize files
with either .m4a or .mp4 format file extensions, as would
be expected, as there are no file format differences between the two. Most
software capable of creating MPEG-4 audio will allow the user to choose the
filename extension of the created MPEG-4 files.
While the only
official file extension defined by the standard is .mp4, various
file extensions are commonly used to indicate intended content:
format files with audio and video generally use the standard .mp4
MPEG-4 files generally have a .m4a extension. This is
especially true of non-protected content.
files with audio streams encrypted by FairPlay Digital Rights
Management as sold through the iTunes
Store use the .m4p extension.
book and podcast files, which also contain metadata including
chapter markers, images, and hyperlinks, can use the extension
.m4a, but more commonly use the .m4b extension. An
M4A format audio file cannot "bookmark" (remember the last
listening spot), whereas .m4b extension files can. Users
can rename .mp4 or .m4a format file extensions to
.m4b to activate these features.
Apple Inc. iPhone uses MPEG-4 audio for its ringtones but uses the
.m4r extension rather than the .m4a extension.
Visual bitstreams are named .m4v.
phones use 3GP, a simplified version of MPEG-4 Part 12 (a.k.a
MPEG-4/JPEG2000 ISO Base Media file format), with the .3gp and
.3g2 extensions. These files also store non-MPEG-4 data (H.263,
The common but
non-standard use of the extensions .m4a format and .m4v is
due to the popularity of Apple’s iPod, the
Store, and the Xbox 360 (in which support for mp4 formatted files was added
to Dashboard in an update in 2007
4Musics M4A to MP3 Converter
Convert M4A Format Files to MP3 and other formats in one click!
The beauty of using 4Musics M4A to MP3 Converter is that
it works from the right click menu on a file. You do not have to
invoke a whole other program to convert M4A Format Files to MP3, WMA, OGG,
WAV, AAC, AMR_NB, AMR_WB, MP2, RA, AC3, AIFF, FLAC, MMF. Besides
4Musics M4A to MP3 Converter includes
M4A Bitrate Changer.
Simply right click on the M4A Format Files, select "Convert to MP3"
or any other formats!
NEW opportunities of work with output files
converting in one click!
fast converting speed;
advanced output format settings;
automatic source deleting;
supporting drag and drop;
System requirements: - Microsoft Windows 95/98/2000/ME/XP
- Pentium 90mhz or better
- 16 MB RAM 7 MB hard drive space
4Musics M4A to MP3 Converter