jamp3
Version:
mp3, id3v1, id3v2 - reader & writer
186 lines (178 loc) • 7.12 kB
text/typescript
import {IID3V1} from '../id3v1/id3v1.types';
import {MP3} from './mp3';
import {IMP3} from './mp3.types';
import {rawHeaderOffSet, rawHeaderSize} from './mp3.mpeg.frame';
import {ITagID} from '../..';
import {checkID3v2} from '../id3v2/id3v2.check';
import {IMP3Analyzer} from './mp3.analyzer.types';
/**
* Class for
* - analyzing ID3v1/2 and MP3 information
*
* Basic usage example:
*
* ```ts
* [[include:snippet_mp3-analyze.ts]]
* ```
* */
export class MP3Analyzer {
/**
* Analyzes a IMP3.Result for ID3v2 errors
* @param data the data to analyzes
* @return a list returning warnings
*/
private analyzeID3v2(data: IMP3.Result): Array<IMP3Analyzer.Warning> {
if (!data.id3v2) {
return [];
}
return checkID3v2(data.id3v2);
}
/**
* Analyzes a IMP3.Result for ID3v1 errors
* @param data the data to analyzes
* @return a list returning warnings
*/
private analyzeID3v1(data: IMP3.Result): Array<IMP3Analyzer.Warning> {
const result: Array<IMP3Analyzer.Warning> = [];
const lastframe: IMP3.FrameRawHeaderArray | undefined = data.frames && data.frames.audio.length > 0 ? data.frames.audio[data.frames.audio.length - 1] : undefined;
if (data.raw && lastframe) {
const audioEnd = rawHeaderOffSet(lastframe) + rawHeaderSize(lastframe);
let id3v1s: Array<IID3V1.Tag> = <Array<IID3V1.Tag>>data.raw.tags.filter(t => t.id === ITagID.ID3v1 && t.start >= audioEnd);
if (id3v1s.length > 0) {
if (id3v1s.length > 1) {
// filter out not yet supported APETAGEX
id3v1s = id3v1s.filter(t => {
return t.value && t.value.title && t.value.title[0] !== 'E' && t.value.title[1] !== 'X' && t.end !== data.size;
});
}
if (id3v1s.length > 1) {
result.push({msg: 'ID3v1: Multiple tags', expected: 1, actual: id3v1s.length});
}
if (id3v1s.length > 0) {
const id3v1 = id3v1s[id3v1s.length - 1];
if (id3v1.end !== data.size) {
result.push({msg: 'ID3v1: Invalid tag position, not at end of file', expected: (data.size - 128), actual: id3v1.start});
}
}
}
}
return result;
}
/**
* Analyzes a IMP3.Result for MPEG errors
* @param data the data to analyzes
* @return a list returning warnings
*/
private analyzeMPEG(data: IMP3.Result): Array<IMP3Analyzer.Warning> {
const result: Array<IMP3Analyzer.Warning> = [];
if (!data.frames || data.frames.audio.length === 0) {
result.push({msg: 'MPEG: No frames found', expected: '>0', actual: 0});
return result;
}
let nextdata = rawHeaderOffSet(data.frames.audio[0]) + rawHeaderSize(data.frames.audio[0]);
data.frames.audio.slice(1).forEach((f, index) => {
if (nextdata !== rawHeaderOffSet(f)) {
result.push({msg: 'MPEG: stream error at position ' + nextdata + ', gap after frame ' + (index + 1), expected: 0, actual: rawHeaderOffSet(f) - nextdata});
}
nextdata = rawHeaderOffSet(f) + rawHeaderSize(f);
});
const audiostart = rawHeaderOffSet(data.frames.audio[0]);
if (data.id3v2 && data.id3v2.head) {
const shouldaudiostart = data.id3v2.start + data.id3v2.head.size + 10; // 10 === id3v2 header
if (audiostart !== shouldaudiostart) {
result.push({msg: 'MPEG: Unknown data found between ID3v2 and audio', expected: 0, actual: audiostart - shouldaudiostart});
}
} else if (audiostart !== 0) {
result.push({msg: 'MPEG: Unknown data found before audio', expected: 0, actual: audiostart});
}
return result;
}
/**
* Analyzes a IMP3.Result for XING errors
* @param data the data to analyzes
* @param ignoreXingOffOne ignore common xing "off by one" error
* @return a list returning warnings
*/
private analyzeXING(data: IMP3.Result, ignoreXingOffOne: boolean): Array<IMP3Analyzer.Warning> {
if (!data.mpeg || !data.frames) {
return [];
}
const head = data.frames.headers[0];
const result: Array<IMP3Analyzer.Warning> = [];
if (!head) {
if (data.mpeg.encoded === 'VBR') {
result.push({msg: 'XING: VBR detected, but no VBR head frame found', expected: 'VBR Header', actual: 'nothing'});
}
return result;
}
if (head.mode === 'Xing' && data.mpeg.encoded === 'CBR') {
result.push({msg: 'XING: Wrong MPEG head frame for CBR', expected: 'Info', actual: 'Xing'});
}
if (head.mode === 'Info' && data.mpeg.encoded === 'VBR') {
result.push({msg: 'XING: Wrong head frame for VBR', expected: 'Xing', actual: 'Info'});
}
if (!ignoreXingOffOne &&
(data.mpeg.frameCount - data.mpeg.frameCountDeclared === 1) &&
(data.mpeg.audioBytes - data.mpeg.audioBytesDeclared === head.header.size)
) {
result.push({msg: 'XING: Wrong ' + head.mode + ' declaration (frameCount and audioBytes must include the ' + head.mode + ' Header itself)', expected: data.mpeg.frameCount, actual: data.mpeg.frameCountDeclared});
} else {
if (data.mpeg.frameCount !== data.mpeg.frameCountDeclared) {
if (!ignoreXingOffOne || Math.abs(data.mpeg.frameCount - data.mpeg.frameCountDeclared) !== 1) {
result.push({msg: 'XING: Wrong number of frames declared in ' + head.mode + ' Header', expected: data.mpeg.frameCount, actual: data.mpeg.frameCountDeclared});
}
}
if (data.mpeg.audioBytes !== data.mpeg.audioBytesDeclared) {
if (!ignoreXingOffOne || data.mpeg.audioBytes + head.header.size - data.mpeg.audioBytesDeclared === 0) {
result.push({msg: 'XING: Wrong number of data bytes declared in ' + head.mode + ' Header', expected: data.mpeg.audioBytes, actual: data.mpeg.audioBytesDeclared});
}
}
}
return result;
}
/**
* Analyzes a file in given path with given options
* @param filename the file to read
* @param options define which information should be analyzed
* @return a object returning analyzed information
*/
async read(filename: string, options: IMP3Analyzer.Options): Promise<IMP3Analyzer.Report> {
const mp3 = new MP3();
const data = await mp3.read(filename, {id3v1: true, id3v2: true, mpeg: true, raw: true});
if (!data || !data.mpeg || !data.frames) {
return Promise.reject(Error('No mpeg data in file:' + filename));
}
const head = data.frames.headers[0];
const info: IMP3Analyzer.Report = {
filename,
mode: data.mpeg.encoded,
bitRate: data.mpeg.bitRate,
channelMode: data.mpeg.mode && data.mpeg.mode.length > 0 ? data.mpeg.mode : undefined,
channels: data.mpeg.channels,
durationMS: data.mpeg.durationRead * 1000,
format: data.mpeg.version && data.mpeg.version.length > 0 ? ('MPEG ' + data.mpeg.version + ' ' + data.mpeg.layer).trim() : 'unknown',
header: head ? head.mode : undefined,
frames: data.mpeg.frameCount,
id3v1: !!data.id3v1,
id3v2: !!data.id3v2,
warnings: [],
tags: {
id3v1: data.id3v1,
id3v2: data.id3v2,
}
};
if (options.mpeg) {
info.warnings = info.warnings.concat(this.analyzeMPEG(data));
}
if (options.xing) {
info.warnings = info.warnings.concat(this.analyzeXING(data, !!options.ignoreXingOffOne));
}
if (options.id3v1) {
info.warnings = info.warnings.concat(this.analyzeID3v1(data));
}
if (options.id3v2 && data.id3v2) {
info.warnings = info.warnings.concat(this.analyzeID3v2(data));
}
return info;
}
}