Sony Ericsson P990i - Manual (Page 30)

White Paper P990i
30 January 2006
Preliminary version - P1F
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Streaming
Media player content is streamed using RTSP (Real
Time Streaming Protocol) session control accord-
ing to 3GPP specification.
Audio support is AAC-LC and AMR-NB according
to 3GPP.
3GPP specifies the following codecs:
• H.263 Profile 0 Level 10.
• MPEG-4 Visual Simple Profile Level 0-3.
• H263 Profile 3 Level 10.
P990i supports the codecs formats as well as:
• Real Audio.
• Real Audio Video.
Media formats
Audio formats
Format Description
AAC-LC Advanced Audio Coding. AAC is the latest audio coding standard, defined in the MPEG-
2 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 per cent lower bit
rate. It supports 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 include: Main Profile
(MP), Low Complexity (LC) and Scalable Sampling Rate (SSR). The Media player can play
AAC-LC format audio which is encoded into an MPEG-4 file or stream. The Sound
recorder use the AAC-LC format for recording.
AMR-NB Adaptive Multi Rate. AMR-NB is a speech compression format that is highly optimized
for the mobile environment, requiring as little as 4.75 Kbps bandwidth. AMR-NB is used
to convey voice recordings in MMS, 3GPP video clips or streams. P990i records AMR
using 12.2 Kbps with a sample rate of 8 kHz.
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. (P990i 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 repre-
sents 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. (P990i 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 inter-
operability 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™.