Sony Ericsson K700 manual Polyphonic ringtones, Wav, Background, Sp-Midi

sizes. A disadvantage is the lack of specific sound control. MIDI is ideal for polyphonic ring- tones.

•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 com- pression method, removing all irrelevant parts of a sound signal that the human ear cannot per- ceive. The result is, for example, CD digital audio (CDDA) 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.

•WAV

Windows media audio video. A wave file is an audio file format created by Microsoft, that has become a standard PC audio file format for everything from system and game sounds to CD-quality audio. A wave file is identified by a file name extension of WAV (.wav). Used prima- rily 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, for example.

In addition to the uncompressed raw audio data, the wave file format stores information about the file's number of tracks (mono or ste- reo), sample rate, and bit depth.

Songs may be stored in the File manager. The folder system enables the user to organize songs into groups and create simple playlists of MP3 songs.

Songs may be collected in numerous ways, including Internet download and file transfer from a PC.

The media player is intelligently aware of other applications in the phone:

•Playback is paused when a telephone call is made or received.

White Paper K700

•Playback is paused if the user starts another application which requires the audio channels to be dedicated to it.

•Playback of MP3 files continues if the user switches to another application, providing music whilst using other applications such as the phonebook or calendar, or playing games.

Polyphonic ringtones

Background

The word “polyphony” means producing several tones at the same time. Almost all music that we listen to consists of polyphonic melodies.

Early Ericsson mobile phones supported a proprietary non-polyphonic format called eMelody. Due to the musical limitations of eMelody, and the popularity of creating, sending and downloading ring melodies, Ericsson and Sony Ericsson, together with other manufacturers, created the more advanced but non-polyphonic sound format – iMelody.

The introduction of the MIDI format revolutionized sound quality. MIDI files are small, and perfect for mobile devices, which have limited storage capacity.

MIDI is a specification for a communications protocol principally used to control electronic musical instruments. MIDI is today a well known standard used by many musicians, composers and arrangers.

A MIDI signal or file does not contain any music. It contains binary data (information) of how a melody is played and when this data reaches a synthesizer, the synthesizer will translate the binary data to music, when connected to an amplifier with speakers so that the sound becomes audible.

Please visit www.midi.org for more information.

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 inter operability between products with different sound capabilities.

12 February 2004