help to play sound sdl2 + ffmpeg

I have a code with which I play video.

// when the stream is a video we store its index, codec parameters and codec
if (pLocalCodecParameters->codec_type == AVMEDIA_TYPE_VIDEO) {
video_stream_index = i;
pCodec = pLocalCodec;
pCodecParameters = pLocalCodecParameters;
//logging(“Video Codec: resolution %d x %d”, pLocalCodecParameters->width, pLocalCodecParameters->height);
else if (pLocalCodecParameters->codec_type == AVMEDIA_TYPE_AUDIO) {

but no sound,
someone can explain me how to reproduce sound with some example.