Convert audio from one format to other using ffmpeg

Convert wav format to dts format

 ./ffmpeg -i ~/sine_440Hz_2ch.wav -codec dts -strict -2 ~/sine_440Hz_2ch.dts 

Use mka container for above dts file

 ./ffmpeg -i ~/sine_440Hz_2ch.dts -vn -acodec copy -f matroska ~/sine_440Hz_2ch.mka 

Convert file from one container format to other

 ffmpeg -i input.mp4 -vcodec copy -acodec copy output.mkv 

Convert wav to ac3 format

 ./ffmpeg -i ~/sine_500Hz_2ch.wav -acodec ac3_fixed -ab 768k -ar 48000 test.ac3 

Use mka container for ac3

 ./ffmpeg -i test.ac3 -vn -acodec copy -f matroska ~/sine_500Hz_2ch-ac3.mka