Music

The media player is a multi-format digital audio player which enables the user to carry and play a selection of favourite songs. A range of audio formats are supported:

•AAC

Advanced Audio Coding. AAC is the latest audio coding standard, defined in the MPEG-4 standard and is used for high-quality audio compression. AAC provides higher quality than MP3 at the same bit rate, or for the same audio quality it uses a 30 percent lower bit rate. It sup- ports the coding of multichannel audio, with up to 48 main channels and 16 low-frequency channels. The AAC offers three different profiles to facilitate trade off between quality, memory and processing power requirements. They are: Main Profile (MP), Low Complexity (LC) and Scalable Sampling Rate (SSR). AAC-LC is sup- ported.

•AMR

Adaptive Multi Rate. A medium quality com- pressed sound format.

•MIDI

Musical Instrument Digital Interface.

Unlike the other formats, 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 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,

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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. A wave file is an audio file format created by Microsoft, that has become a standard computer audio file format for everything from system and game sounds to quality audio. 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 con- tent 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 are stored in My Items. In the folder system the user can organize songs into groups. In the Media Player the user can create simple play- lists of songs.

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

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

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

•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 calendar or contacts, 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.

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August 2005