FFMPEG acode AMR_NB not found error

[kamalakar108]

Dear all,
I am converting m4a files in my folder to amr using the following batch command.

for %%a in ("*.*") do ffmpeg -i "%%a" -ar 8000 -ab 12.2k "amrfiles\%%~na.amr"

it gives me error Unknown encoder 'amr_nb'
I listed the codecs using ffmpeg -codecs.
it shows

D.A.L. amr_nb AMR-NB (Adaptive Multi-Rate NarrowBand) (decoders: amrnb )
D.A.L. amr_wb AMR-WB (Adaptive Multi-Rate WideBand) (decoders: amrwb )
Kindly help how to overcome this error
Regards
kamalakar

[october262]

Dear all,
I am converting m4a files in my folder to amr using the following batch command.

for %%a in ("*.*") do ffmpeg -i "%%a" -ar 8000 -ab 12.2k "amrfiles\%%~na.amr"

it gives me error Unknown encoder 'amr_nb'
I listed the codecs using ffmpeg -codecs.
it shows

D.A.L. amr_nb AMR-NB (Adaptive Multi-Rate NarrowBand) (decoders: amrnb )
D.A.L. amr_wb AMR-WB (Adaptive Multi-Rate WideBand) (decoders: amrwb )
Kindly help how to overcome this error
Regards
kamalakar

see step 3 - https://stackoverflow.com/questions/41144655/how-to-convert-audio-m4a-to-audio-amr-on-os-x
try adding audio.amr after -ab 12.2k

[kamalakar108]

Thanks a lot for the help.with your suggestion i started working weather it works for all names of files. the files names i having are a mix of telugu and english characters. hence it is giving challenge. when i made them simple just worked fine. i need to understand how to make UTF-8 on my dos command

[kamalakar108]

To enable Telugu Character i used chcp 65001
It is working fine now.
Appreciate your help in making me to relook at my challenge