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Source code


Name: ima_adpcm_encoder
Created: Nov 5, 2008
Updated: Apr 27, 2011
SVN Updated: Mar 10, 2009

Other project properties

Category: Other
Language: VHDL
Development status: Stable
Additional info: Design done , FPGA proven , Specification done
WishBone Compliant: Yes
License: GPL


This project features a full-hardware sound compressor using the well known algorithm: IMA ADPCM.
The core acts as a slave WISHBONE device.
The output is perfectly compatible with any sound player with the IMA ADPCM codec (included by default in every Windows). Includes a testbench that takes an uncompressed PCM 16 bits Mono WAV file and outputs an IMA ADPCM compressed WAV file.
Compression ratio is fixed for IMA-ADPCM, being 4:1.
PLEASE NOTICE THAT THIS CORE IS LICENSED UNDER http://creativecommons.org/licenses/by-nc-sa/3.0/ (Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported). That means you may use it only for NON-COMMERCIAL purposes.


- IMA ADPCM Compression (4 bits per sample)
- Input must be 16 bits PCM sound samples
- Only one channel (mono)
- Output includes standard WAV headers
- Selectable sample rate and number of seconds of recording
- Fully Wishbone compliant core (acts as a Wishbone slave)
- Testbench included that takes a 16 bits PCM Mono WAV file and writes to disk another WAV file of the sound compressed with IMA ADPCM.


- 05/11/2008: Project created