/*
* Copyright (C) 2016 Bilibili. All Rights Reserved.
*
* @author zheng qian <xqq@xqq.im>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import Log from '../utils/logger.js';
import decodeUTF8 from '../utils/utf8-conv.js';
import {IllegalStateException} from '../utils/exception.js';
let le = (function () {
let buf = new ArrayBuffer(2);
(new DataView(buf)).setInt16(0, 256, true); // little-endian write
return (new Int16Array(buf))[0] === 256; // platform-spec read, if equal then LE
})();
class AMF {
static parseScriptData(arrayBuffer, dataOffset, dataSize) {
let data = {};
try {
let name = AMF.parseValue(arrayBuffer, dataOffset, dataSize);
let value = AMF.parseValue(arrayBuffer, dataOffset + name.size, dataSize - name.size);
data[name.data] = value.data;
} catch (e) {
Log.e('AMF', e.toString());
}
return data;
}
static parseObject(arrayBuffer, dataOffset, dataSize) {
if (dataSize < 3) {
throw new IllegalStateException('Data not enough when parse ScriptDataObject');
}
let name = AMF.parseString(arrayBuffer, dataOffset, dataSize);
let value = AMF.parseValue(arrayBuffer, dataOffset + name.size, dataSize - name.size);
let isObjectEnd = value.objectEnd;
return {
data: {
name: name.data,
value: value.data
},
size: name.size + value.size,
objectEnd: isObjectEnd
};
}
static parseVariable(arrayBuffer, dataOffset, dataSize) {
return AMF.parseObject(arrayBuffer, dataOffset, dataSize);
}
static parseString(arrayBuffer, dataOffset, dataSize) {
if (dataSize < 2) {
throw new IllegalStateException('Data not enough when parse String');
}
let v = new DataView(arrayBuffer, dataOffset, dataSize);
let length = v.getUint16(0, !le);
let str;
if (length > 0) {
str = decodeUTF8(new Uint8Array(arrayBuffer, dataOffset + 2, length));
} else {
str = '';
}
return {
data: str,
size: 2 + length
};
}
static parseLongString(arrayBuffer, dataOffset, dataSize) {
if (dataSize < 4) {
throw new IllegalStateException('Data not enough when parse LongString');
}
let v = new DataView(arrayBuffer, dataOffset, dataSize);
let length = v.getUint32(0, !le);
let str;
if (length > 0) {
str = decodeUTF8(new Uint8Array(arrayBuffer, dataOffset + 4, length));
} else {
str = '';
}
return {
data: str,
size: 4 + length
};
}
static parseDate(arrayBuffer, dataOffset, dataSize) {
if (dataSize < 10) {
throw new IllegalStateException('Data size invalid when parse Date');
}
let v = new DataView(arrayBuffer, dataOffset, dataSize);
let timestamp = v.getFloat64(0, !le);
let localTimeOffset = v.getInt16(8, !le);
timestamp += localTimeOffset * 60 * 1000; // get UTC time
return {
data: new Date(timestamp),
size: 8 + 2
};
}
static parseValue(arrayBuffer, dataOffset, dataSize) {
if (dataSize < 1) {
throw new IllegalStateException('Data not enough when parse Value');
}
let v = new DataView(arrayBuffer, dataOffset, dataSize);
let offset = 1;
let type = v.getUint8(0);
let value;
let objectEnd = false;
try {
switch (type) {
case 0: // Number(Double) type
value = v.getFloat64(1, !le);
offset += 8;
break;
case 1: { // Boolean type
let b = v.getUint8(1);
value = b ? true : false;
offset += 1;
break;
}
case 2: { // String type
let amfstr = AMF.parseString(arrayBuffer, dataOffset + 1, dataSize - 1);
value = amfstr.data;
offset += amfstr.size;
break;
}
case 3: { // Object(s) type
value = {};
let terminal = 0; // workaround for malformed Objects which has missing ScriptDataObjectEnd
if ((v.getUint32(dataSize - 4, !le) & 0x00FFFFFF) === 9) {
terminal = 3;
}
while (offset < dataSize - 4) { // 4 === type(UI8) + ScriptDataObjectEnd(UI24)
let amfobj = AMF.parseObject(arrayBuffer, dataOffset + offset, dataSize - offset - terminal);
if (amfobj.objectEnd)
break;
value[amfobj.data.name] = amfobj.data.value;
offset += amfobj.size;
}
if (offset <= dataSize - 3) {
let marker = v.getUint32(offset - 1, !le) & 0x00FFFFFF;
if (marker === 9) {
offset += 3;
}
}
break;
}
case 8: { // ECMA array type (Mixed array)
value = {};
offset += 4; // ECMAArrayLength(UI32)
let terminal = 0; // workaround for malformed MixedArrays which has missing ScriptDataObjectEnd
if ((v.getUint32(dataSize - 4, !le) & 0x00FFFFFF) === 9) {
terminal = 3;
}
while (offset < dataSize - 8) { // 8 === type(UI8) + ECMAArrayLength(UI32) + ScriptDataVariableEnd(UI24)
let amfvar = AMF.parseVariable(arrayBuffer, dataOffset + offset, dataSize - offset - terminal);
if (amfvar.objectEnd)
break;
value[amfvar.data.name] = amfvar.data.value;
offset += amfvar.size;
}
if (offset <= dataSize - 3) {
let marker = v.getUint32(offset - 1, !le) & 0x00FFFFFF;
if (marker === 9) {
offset += 3;
}
}
break;
}
case 9: // ScriptDataObjectEnd
value = undefined;
offset = 1;
objectEnd = true;
break;
case 10: { // Strict array type
// ScriptDataValue[n]. NOTE: according to video_file_format_spec_v10_1.pdf
value = [];
let strictArrayLength = v.getUint32(1, !le);
offset += 4;
for (let i = 0; i < strictArrayLength; i++) {
let val = AMF.parseValue(arrayBuffer, dataOffset + offset, dataSize - offset);
value.push(val.data);
offset += val.size;
}
break;
}
case 11: { // Date type
let date = AMF.parseDate(arrayBuffer, dataOffset + 1, dataSize - 1);
value = date.data;
offset += date.size;
break;
}
case 12: { // Long string type
let amfLongStr = AMF.parseString(arrayBuffer, dataOffset + 1, dataSize - 1);
value = amfLongStr.data;
offset += amfLongStr.size;
break;
}
default:
// ignore and skip
offset = dataSize;
Log.w('AMF', 'Unsupported AMF value type ' + type);
}
} catch (e) {
Log.e('AMF', e.toString());
}
return {
data: value,
size: offset,
objectEnd: objectEnd
};
}
}
export default AMF;