base64转amr文件

function dataURL2Audio(fname, base64Str, callback) { //base64转amr文件
var mv = base64Str || '';
if(typeof callback != 'function' || mv == '') return;
fname = fname || ((new Date()).getTime());
fname = (fname.indexOf('.amr') == fname.length - 4) ? fname : fname + '.amr';
var audioName = '_doc/audio/' + fname;
plus.io.requestFileSystem(plus.io.PRIVATE_DOC, function(fs) {
fs.root.getFile(audioName, {
create: true
}, function(entry) {
var fullPath = entry.fullPath;
if(mui.os.android) {
var Str = plus.android.importClass("java.lang.String");
var FileOutputStream = plus.android.importClass("java.io.FileOutputStream");
try {
var myatb, bstr;
var out = new FileOutputStream(fullPath);
var mystr = atob(mv);
var mlen = mystr.length;
var sstr = '';
while(mlen > 0) {
mysub = mystr.substr(0, 1000);
mystr = mystr.substr(1000);
mlen = mystr.length;
myatb = new Str(mysub);
bstr = myatb.getBytes("ISO8859-1");
out.write(bstr);
}
out.close();
callback && callback(entry); // 回调
} catch(ex) {
console.log('写入失败');
}
} else if(mui.os.ios) {
var NSData = plus.ios.importClass('NSData');
var nsData = new NSData();
nsData = nsData.initWithBase64EncodedStringoptions(mv, 0);
if(nsData) {
nsData.plusCallMethod({
writeToFile: fullPath,
atomically: true
});
plus.ios.deleteObject(nsData);
}
callback && callback(entry); // 回调
}
})
})
}