MPEG decoder contains MPEG1/2/2.5 Layer 1/2/3 with support of constant bitrate. It decompresses the MPEG1/2/2.5 Layer 1/2/3 format audio files and produces the PCM samples.

Layers are distinguished based on their encoder's complexity and its compression ratio. Layer's complexity and compression ratios increase from Layer 1 to Layer 3. Layers have its own advantages and limitations, so users need to select the layer based on their requirements.

MPEG1/2/2.5 Layer 3 decoder is an audio decoding technology which is based on subbanding using polyphase filter banks. The compressed audio data is parsed in 32 subbands. For each subband, parameters like scale factor bands coefficients, number of bits allocated to each sample are decoded. Using these parameters, audio samples are decompressed by requantization and Hybrid filter banks techniques.

MPEG1/2/2.5 Layer 1/2 decoder is an audio decoding technology which is also based on subbanding technique. For each subband, parameters like scale factor bands coefficients, number of bits allocated to each sample are decoded. Using these parameters, audio samples are decompressed by Subband synthesis filter.

• Supports MPEG 1/2/ 2.5 Layer 1/2/3
• Supports mono, dual, stereo, MS stereo, Intensity stereo modes
• Supports sampling frequencies from 8 - 48 KHz
• Supports bit rates from 8 - 320 Kbps

ARM946E-S with 8KB instruction cache, 8KB data cache, no TCM (Tightly Coupled Memory).

• Memory Requirements

Layer	ROM (Bytes)		RAM (Bytes)
	Code	Table	Stack	Data
1	22576	19856	328	20364
2				22668
3				27276

• MIPS
Benchmark File characteristics: 48000 Hz, 320 KBPS, stereo

Layer	MIPS
Layer 1	25.03
Layer 2	23.42
Layer 3	38.67