After watching the file upload episode from eventedmind.com, it turns out the way to do it is to use the FileReader to read a blob as ArrayBuffer, which is then converted to Uint8Array to be stored in mongo:
var BinaryFileReader = {
read: function(file, callback){
var reader = new FileReader;
var fileInfo = {
name: file.name,
type: file.type,
size: file.size,
file: null
}
reader.onload = function(){
fileInfo.file = new Uint8Array(reader.result);
callback(null, fileInfo);
}
reader.onerror = function(){
callback(reader.error);
}
reader.readAsArrayBuffer(file);
}
}
The exportWAV callback is then
recorder.exportWAV(function(blob) {
BinaryFileReader.read(blob, function(err, fileInfo){
Recordings.insert(fileInfo)
});
});
Then I can display one of my recordings by:
Deps.autorun(function(){
var rec = Recordings.findOne();
if (rec){
var au = document.createElement('audio');
au.controls = true;
var blob = new Blob([rec.file],{type: rec.type});
au.src = URL.createObjectURL(blob);
document.getElementById("recordingslist").appendChild(au);
}
})
I don't know if the previous snippet works in other browsers, but this may:
var base64Data = btoa(String.fromCharCode.apply(null, rec.file))
var au = document.createElement('audio');
au.controls = true;
au.src = "data:"+rec.type+";base64,"+base64Data