MP3 DECODING INTO NATIVE FILE.

[Shariff]

Hi Engineers, 

I am developing an MP3 player for which I need help to convert mp3 files available in SD card into native file and to transmit through i2s to the DAC.

I tried playing .WAV formatted file, it is able to play but still have some glitches and tick sounds with it.

However the .WAV is very large in size so i want to use mp3 files. 

Before sending into DAC the mp3 file has to be converted to uncompressed form.

Please help me, suggest me how to do it.

Thanks.

[ovrebekk]

Hi Ajmal

Unfortunately we don't have any examples showing how to do mp3 decompression on the nRF devices. 

As mentioned by Jörg this is a pretty CPU and memory intensive operation, and you might not be able to do this efficiently in the nRF52840 even if you manage to find a library to do it. 

What kind of bit depth and sample rate are you using? 
It should be possible to playback CD quality wave files directly from an SD card, as long as the communication with the SD card is handled efficiently. 

Another option is to use the new LC3 codec which is the basis for the new LE Audio standard. LC3 is supported on our devices, and is less CPU intensive meaning you can run it realtime on the nRF52 series. 

Best regards
Torbjørn