Microchip Technology Inc

Helix MP3 Decoder Library for PIC32


The Helix MP3 decoder provides Layer 3 support for MPEG-1, MPEG-2, and MPEG-2.5. It supports variable bit rates, constant bit rates, and stereo and mono audio formats. This library implements fixed point solution for PIC32 MCUs.

Run-Time Library Loading (RTLL)

The Helix MP3 decoder source code is open source and is governed by the license described in files that accompany the source code(1). However, Application developers may need to add proprietary code to open source code to meet the target application requirements. When statically compiled with the open source code, this proprietary code may be subject to the open source End User License Agreement. In many cases, this may not be acceptable to application owners. Therefore, this library provides a Run-Time Library Loading (RTLL) technique that enables the preservation of the application’s intellectual property.

Notes: 1) It should be noted that even though the Helix MP3 decoder is free to use and

is open source, the MP3 algorithm itself is not free and has royalties associated with it. These royalties must be paid in order to use the algorithm. For more details, visit http://www.mp3licensing.com


Features(1)

Pure 32-bit fixed-point implementation

Fully reentrant and statically linkable

Designed for high performance and low power consumption in handheld and mobile devices

Full layer 3 support for:

 

MPEG1 layer 3 - sampling frequencies: 48 KHz, 44.1 KHz, 32 KHz

 

MPEG2 layer 3 - sampling frequencies: 24 KHz, 22.05 KHz, 16 KHz

 

MPEG2.5 layer 3 - sampling frequencies: 12 KHz, 11.025 KHz, 8 KHz

Supports constant bitrate, variable bitrate, and free bitrate modes

Supports mono and all stereo modes (normal stereo, joint stereo, dual-mono)

Notes: 1) For more information on implementation and features, visit the Helix MP3 decoder web site at:http://datatype.helixcommunity.org/Mp3dec

Memory Requirements for PIC32

Memory Type

Size (in bytes)

Remarks

Program Memory

53000

-

Data Memory

28000

Required by decoder only

Input Buffer

1940

Max MP3 frame size

Output Buffer

2304

Max size for stereo mode


MIPS Requirements for PIC32

Function

MIPS

Remarks

MP3Decode()

26

Calculated with code compiled with O3 optimization and processor clock at 80 MHz.

Downloads

Description
Download
KB Size
Updated as of
AN1367_Source_Code_for_PIC32_MEB_102111
7783
10/16/2014
01367A
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10/16/2014