ADPCM encoder and decoder

IMA based ADPCM encoder and decoder.

Description

M-file to perform ADPCM encode and decode. The algorithm is based on IMA ADPCM.

• MATLAB release: MATLAB 7 (R14)

[amar m]

 

[omair gillani]

 

[sibasish nandi]

decoder is not working

[Lutz Berdteerede]

retre

[C.Y. Chen]

just copied from Microchip's Application Note 643 (as mentioned by the author), but both works fine (this decoder only work with signal encoded by this encoder)

[bank tom]

have a look

[lumianic kazama]

Input argument 'raw_y' is undefined.
Error in ==> C:\MATLAB6p1\work\adpcm_encoder.m
On line 17 ==> Ns = length(raw_y);
i have this error when try to run the file, can you try to debug it ?i use matlab6

[Dov Alperin]

It seems to me like

A. The encoder is limited to a certain quantization level, aka. if you get higher than a certain level, the signal clips.

B. The decoder, I think has a negative amplifier, and thus I get a much smaller output from the decoder than I expect

[jen market]

 

[teja veeramachaneni]

 

[Satiyan kaliyamoorthy]

 

[arpita chitnis]

'raw_y' is not defined.
Error in ==> C:\MATLAB7\work\adpcm_encoder.m
On line 17 ==> Ns = length(raw_y);

i am not able to understand as to why am i getting this error. Please help.

[firman yudhistira]

not work

[Daniel Acevedo]

The code works but is extremely slow because some key variables are not pre-allocated. After preallocation, it's reasonably fast for long signals.

[liao]

have a look