I am seeking a SIP-client that allows playing audio file to the answerer, wav, mp3, mp4, no matter which type of audio. Are there any option besides command-line ones?
I tried Phoner, it claims to support this but he does this very bad. The person I am calling to cannot hear almost nothing, just a mumbling and whispering. The quality of the audio rendering is very bad.
Any suggestions? I am open both to Desktop (incl. Linux) and Android options.