lpcware

How to reduce the Helix MP3 decoder decoding time for LPC4350 (M4)

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by srinu282 on Wed Feb 06 00:20:07 MST 2013
Hi All,
        Am using Hitex Board-LPC4350(M4,M0) for audio application. Referring AN11178( MP3 player solution on NXP LPC1700 series) document and took the helix MP3 decoder code from
https://datatype.helixcommunity.org/Mp3dec . In M4 using  is code to decode MP3  to PCM Conversion .

M4 Core SPEED : 192MHZ

SDCARD CLK : 34MHZ.
I2S configuration : 16bit,MONO,44.1kHZ.    
   MP3 files is  reading from SDCARD. For 4K data read time : 2.8ms.
  To decode one frame using Helix MP3 decoder : 110ms.
DMA transfor : 12ms  
For MP3, the duration of playing a single frame is fixed at ~26 ms.
How can I reduce Helix MP3 decoder decoding time?
As per AN11178 document helix MP3 decoder code is optimized for Fixed point decoder.
How can i choose fixed point decoder in my application?
Tried the option like in KEIL project “target”--floating  point hardware  Not used
No change in timing (110ms). How can I reduce MP3 decoder decoding time to 8ms from 110ms?

  

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