Accoding to Table 2-4 of FairPlay Programing Guide, Asset ID in SPC is byte array.On other hand, the chapter EME Message Exchange says The AssetId can be any string you choose.So what charactor code should I choose?In FPS_in_Safari_Example.html, charactor code of AssetId is like Unicode.Its javascript code to get byte array is the below: function stringToArray(string) { var buffer = new ArrayBuffer(string.length*2); // 2 bytes for each char var array = new Uint16Array(buffer); for (var i=0, strLen=string.length; i<strLen; i++) { array[i] = string.charCodeAt(i); } return array; }The length of Unicode is not always 2 bytes. So it will not working well because Key Server can't extract original string.It doesn't make sense to treat Asset Id as string in Safari.Should I pass AssetId to Key Server in the outer of SPC Message?