Protobuf: Serialize/DeSerialize C++ to Js - c++

Question

I'm using protobuf to send/receive binary data from Cpp to Js and vice-versa and I'm using QWebChannel to communicate with the HTML client.
Question: How to deserialize binary data in cpp which is serialized and sent from Js?
Following I tried:
//Serialization: Cpp to JS - WORKING
tutorial::PhoneNumber* ph = new tutorial::PhoneNumber();
ph->set_number("555-515-135");
ph->set_type(500);
QByteArray bytes = QByteArray::fromStdString(ph->SerializeAsString());
QString args = "\"" + bytes.toBase64(QByteArray::Base64Encoding) + "\"";
QString JsFunctionCall = QString("DeserializePhoneNumber(%1);").arg(args);
m_pWebView->page()->runJavaScript(JsFunctionCall);
//Deserialization In JS - Js Code - WORKING
var obj = phone_msg.PhoneNumber.deserializeBinary(data);
console.log("PhoneNumber: " + obj.getNumber());
console.log("Type: " + obj.getType());
//Serialization in Js - WORKING
var phNum = new phone_msg.PhoneNumber;
phNum.setNumber("555-515-135");
phNum.setId(500);
var base64Str = btoa(phNum.serializeBinary());
console.log("base64Str: " + base64Str);
//Call Cpp function from Js
MainChannel.SendMsgToCpp(base64Str);
Deserialization in Cpp - NOT WORKING
bool WebRelay::ReceiveMsgFromJs(QVariant data)
{
QString str = data.toString();
QByteArray bytedata = str.toLatin1();
QByteArray base64data = QByteArray::fromBase64(bytedata);
std::string stdstr = base64data.toStdString();
tutorial::PhoneNumber cppPhNum;
//THIS IS NOT WORKING. Text and id are invalid
cppPhNum.ParseFromArray(base64data.constData(), base64data.size());
qDebug() << "Text:" << itemData.number();
qDebug() << "id:" << cppPhNum.id();
}

Answer 1

Found the problem.
I was getting comma-separated bytes from Js like:
10,7,74,115,73,116,101,109,49,16,45
I split the strings by ',' and created a QByteArray
QStringList strList = str.split(',');
QByteArray bytedata;
foreach(const QString & str, strList)
{
bytedata+= (str.toUInt());
}
std::string stdstr = bytedata.toStdString();
itemData.ParseFromString(stdstr);
It works.
Also in JS, I removed convertion of the binary string to base64:
var base64Str = phNum.serializeBinary();