music-metadata
Version:
Music metadata parser for Node.js, supporting virtual any audio and tag format.
137 lines • 7.15 kB
JavaScript
import initDebug from 'debug';
import { TrackType } from '../type.js';
import GUID from './GUID.js';
import * as AsfObject from './AsfObject.js';
import { BasicParser } from '../common/BasicParser.js';
import { AsfContentParseError } from './AsfObject.js';
const debug = initDebug('music-metadata:parser:ASF');
const headerType = 'asf';
/**
* Windows Media Metadata Usage Guidelines
* - Ref: https://msdn.microsoft.com/en-us/library/ms867702.aspx
*
* Ref:
* - https://tools.ietf.org/html/draft-fleischman-asf-01
* - https://hwiegman.home.xs4all.nl/fileformats/asf/ASF_Specification.pdf
* - http://drang.s4.xrea.com/program/tips/id3tag/wmp/index.html
* - https://msdn.microsoft.com/en-us/library/windows/desktop/ee663575(v=vs.85).aspx
*/
export class AsfParser extends BasicParser {
async parse() {
const header = await this.tokenizer.readToken(AsfObject.TopLevelHeaderObjectToken);
if (!header.objectId.equals(GUID.HeaderObject)) {
throw new AsfContentParseError(`expected asf header; but was not found; got: ${header.objectId.str}`);
}
try {
await this.parseObjectHeader(header.numberOfHeaderObjects);
}
catch (err) {
debug('Error while parsing ASF: %s', err);
}
}
async parseObjectHeader(numberOfObjectHeaders) {
let tags;
do {
// Parse common header of the ASF Object (3.1)
const header = await this.tokenizer.readToken(AsfObject.HeaderObjectToken);
// Parse data part of the ASF Object
debug('header GUID=%s', header.objectId.str);
switch (header.objectId.str) {
case AsfObject.FilePropertiesObject.guid.str: { // 3.2
const fpo = await this.tokenizer.readToken(new AsfObject.FilePropertiesObject(header));
this.metadata.setFormat('duration', Number(fpo.playDuration / BigInt(1000)) / 10000 - Number(fpo.preroll) / 1000);
this.metadata.setFormat('bitrate', fpo.maximumBitrate);
break;
}
case AsfObject.StreamPropertiesObject.guid.str: { // 3.3
const spo = await this.tokenizer.readToken(new AsfObject.StreamPropertiesObject(header));
this.metadata.setFormat('container', `ASF/${spo.streamType}`);
break;
}
case AsfObject.HeaderExtensionObject.guid.str: { // 3.4
const extHeader = await this.tokenizer.readToken(new AsfObject.HeaderExtensionObject());
await this.parseExtensionObject(extHeader.extensionDataSize);
break;
}
case AsfObject.ContentDescriptionObjectState.guid.str: // 3.10
tags = await this.tokenizer.readToken(new AsfObject.ContentDescriptionObjectState(header));
await this.addTags(tags);
break;
case AsfObject.ExtendedContentDescriptionObjectState.guid.str: // 3.11
tags = await this.tokenizer.readToken(new AsfObject.ExtendedContentDescriptionObjectState(header));
await this.addTags(tags);
break;
case GUID.CodecListObject.str: {
const codecs = await AsfObject.readCodecEntries(this.tokenizer);
codecs.forEach(codec => {
this.metadata.addStreamInfo({
type: codec.type.videoCodec ? TrackType.video : TrackType.audio,
codecName: codec.codecName
});
});
const audioCodecs = codecs.filter(codec => codec.type.audioCodec).map(codec => codec.codecName).join('/');
this.metadata.setFormat('codec', audioCodecs);
break;
}
case GUID.StreamBitratePropertiesObject.str:
// ToDo?
await this.tokenizer.ignore(header.objectSize - AsfObject.HeaderObjectToken.len);
break;
case GUID.PaddingObject.str:
// ToDo: register bytes pad
debug('Padding: %s bytes', header.objectSize - AsfObject.HeaderObjectToken.len);
await this.tokenizer.ignore(header.objectSize - AsfObject.HeaderObjectToken.len);
break;
default:
this.metadata.addWarning(`Ignore ASF-Object-GUID: ${header.objectId.str}`);
debug('Ignore ASF-Object-GUID: %s', header.objectId.str);
await this.tokenizer.readToken(new AsfObject.IgnoreObjectState(header));
}
} while (--numberOfObjectHeaders);
// done
}
async addTags(tags) {
await Promise.all(tags.map(({ id, value }) => this.metadata.addTag(headerType, id, value)));
}
async parseExtensionObject(extensionSize) {
do {
// Parse common header of the ASF Object (3.1)
const header = await this.tokenizer.readToken(AsfObject.HeaderObjectToken);
const remaining = header.objectSize - AsfObject.HeaderObjectToken.len;
// Parse data part of the ASF Object
switch (header.objectId.str) {
case AsfObject.ExtendedStreamPropertiesObjectState.guid.str: // 4.1
// ToDo: extended stream header properties are ignored
await this.tokenizer.readToken(new AsfObject.ExtendedStreamPropertiesObjectState(header));
break;
case AsfObject.MetadataObjectState.guid.str: { // 4.7
const moTags = await this.tokenizer.readToken(new AsfObject.MetadataObjectState(header));
await this.addTags(moTags);
break;
}
case AsfObject.MetadataLibraryObjectState.guid.str: { // 4.8
const mlTags = await this.tokenizer.readToken(new AsfObject.MetadataLibraryObjectState(header));
await this.addTags(mlTags);
break;
}
case GUID.PaddingObject.str:
// ToDo: register bytes pad
await this.tokenizer.ignore(remaining);
break;
case GUID.CompatibilityObject.str:
await this.tokenizer.ignore(remaining);
break;
case GUID.ASF_Index_Placeholder_Object.str:
await this.tokenizer.ignore(remaining);
break;
default:
this.metadata.addWarning(`Ignore ASF-Object-GUID: ${header.objectId.str}`);
// console.log("Ignore ASF-Object-GUID: %s", header.objectId.str);
await this.tokenizer.readToken(new AsfObject.IgnoreObjectState(header));
break;
}
extensionSize -= header.objectSize;
} while (extensionSize > 0);
}
}
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