AMR-WB

AMR-WB Codec

This project provides the AMR-WB encoder/decoder optimized for Nuclei CPUs.

The decoder source code comes from opencore-amr (current version :0.1.6).

The encoder source code comes from vo-amrwbenc (current version: 0.1.3).

File Structure

Directory	Description
amrwb_dec	AMR-WB decoding source files
amrwb_enc	AMR-WB decoding source files
audio	audio files used for test
bin	binaries to generate reference results
data	pre-generated test data

Prerequests

Please refer to the Prerequests section in the parent directory's README.

Build

Switch to the directory containing the Makefile.
Below are build examples for the Nuclei N300 CPU.

Build without extension:

make CORE=n300 ARCH_EXT= all

Build with B and P extension:

make CORE=n300 ARCH_EXT=_zba_zbb_zbc_zbs_xxldspn3x all

For details about Nuclei CPU architecture extensions, see the ARCH_EXT section in the Nuclei SDK documentation.

Performance Test

Generate Test Data

Codec performance depends on both bitrate and input audio data.
To simplify testing with different bitrates and audio files, a helper script is provided:

👉 bin/gendata.sh

Note

This script is only supported on Linux x86_64
It relies on prebuilt binaries (encoder/decoder) available only for x86_64.
You may also build these binaries yourself if needed.

To view usage details:

./bin/gendata.sh -h

Expected Output

Run encoder and decoder in two corresponding sub-directories.

cd amrwb_enc
make CORE=n300 ARCH_EXT=_zba_zbb_zbc_zbs_xxldspn3x all upload
cd ../amrwb_dec
makr CORE=n300 ARCH_EXT=_zba_zbb_zbc_zbs_xxldspn3x all upload

A typical output looks like this:

Nuclei SDK Build Time: Sep  9 2025, 19:26:18
Download Mode: ILM
CPU Frequency 16006512 Hz
CPU HartID: 0
bitrate: 6600
CSV, amrwb_encode, 40.71
PASS

Nuclei SDK Build Time: Sep  9 2025, 19:26:38
Download Mode: ILM
CPU Frequency 16004546 Hz
CPU HartID: 0
CSV, amrwb_decode, 12.13
PASS

The key results are prefixed with CSV, making them easy to parse in scripts for further analysis.

The performance metric is reported in MCPS (Milion Cycles Per Second), which represents the number of CPU cycles required to process one second of audio data.