White paper
Sony Ericsson P1
30
May 2007
AU
Similar to WAV, this is an audio format commonly used in the Macintosh, Unix and
Java™ worlds. It is not commonly used for content on mobile devices.
iMelody
A format commonly used for monophonic ringtones. (Sony Ericsson P1 ringtones can
use up to 40 voices.)
MIDI
Musical Instrument Digital Interface. MIDI is not a recording of music, but a description
which enables a local synthesizer to play the music from the instructions included in
the MIDI file. Since a MIDI file only represents player information, it is far more concise
than formats that store the sound directly. An advantage is very small file sizes. A
disadvantage is the lack of specific sound control. MIDI is ideal for polyphonic
ringtones. (Sony Ericsson P1 ringtones can use up to 40 voices.)
SP-MIDI
SP-MIDI stands for Scalable Polyphony MIDI. SP-MIDI is based on the MIDI format and
adapted for mobile phones and other portable products. The objective is to secure
interoperability between products with different sound capabilities.
Initial recommendations for using SP-MIDI in 3GPP™ applications are discussed in a
separate document, “Scalable Polyphony MIDI Device 5-24 Note Profile for 3GPP™”.
MP3
MP3 is the file extension for MPEG audio layer 3. Layer 3 is one of three coding
schemes (layer 1, layer 2 and layer 3) for the compression of audio signals. Layer 3
uses a very efficient compression method, removing all irrelevant parts of a sound
signal that the human ear cannot perceive. The result is, CD digital audio (CDDA) is
converted to MP3 with almost
untouched quality, compressed by a factor of around
12. The high compression of audio in MP3 files makes them relatively small, though
MP3 files can be created with different size and quality compromises. The small file
size, together with the excellent sound quality, are the main reasons for the MP3-
format’s massive popularity when sharing music over the Internet.
RMF
Rich Music Format™. A file format developed by Beatnik combining the compact size
of MIDI files with the high quality of sampled sound.
WAV
A wave file is identified by a file name extension of WAV (.wav). Used primarily in PCs,
the wave file format has been accepted as a viable interchange medium for other
computer platforms, such as Macintosh. This allows content developers to freely move
audio files between platforms for processing.
In addition to the uncompressed raw audio data, the wave file format stores
information about the file's number of tracks (mono or stereo), sample rate, and bit
depth.
WMA
Windows Media Audio (WMA) is a proprietary compressed audio file format developed
by Microsoft. It was initially intended to be a competitor to the popular MP3 format,
but has not yet received such popularity.
XMF
Xtended Music Format. XMF is a technology for collecting other music and sound
resources, such as Standard MIDI Files, DLS instrument files, WAV or other digital
audio files. XMF does not describe musical notes, notations, instrument sounds or
audio recordings. Instead, it offers content creators a method to collect all those
elements and put them in a single file. In the end, this means easier handling and more
consistent predictable playback.
