echo_stream_new
echo_stream *echo_stream_new(echo_dev *card, uint8 use, uint32 bufframes, uint8 bufcount);
stream = echo_stream_new(card, ECHO_USE_PLAY, current_settings.buffer_frames, current_settings.buffer_count);
stream = echo_stream_new(card, ECHO_USE_RECORD, current_settings.buffer_frames, current_settings.buffer_count);