JS FLACMetadataEditor

Allows you to edit metadata of FLAC files. CO

此脚本不应直接安装。它是供其他脚本使用的外部库,要使用该库请加入元指令 // @require https://update.gf.qytechs.cn/scripts/40545/646530/JS%20FLACMetadataEditor.js

您需要先安装一个扩展,例如 篡改猴Greasemonkey暴力猴,之后才能安装此脚本。

You will need to install an extension such as Tampermonkey to install this script.

您需要先安装一个扩展,例如 篡改猴暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴Userscripts ,之后才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey,才能安装此脚本。

您需要先安装用户脚本管理器扩展后才能安装此脚本。

(我已经安装了用户脚本管理器,让我安装!)

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

(我已经安装了用户样式管理器,让我安装!)

/* jslint esversion: 6, bitwise: true */

// ==UserScript==
// @name        JS FLACMetadataEditor
// @description Allows you to edit metadata of FLAC files. CO
// @namespace   universe.earth.www.ahohnmyc
// @version     0.0.2.1
// @license     GPL-3.0-or-later
// @grant       none
// ==/UserScript==

const FLACMetadataEditor = (()=>{
    'use strict';

    const _version = '0.0.2.1';

    class VorbisComment extends Array {}

    class VorbisCommentPacket {
        /* Need to easy initialization */
        _addComment(field) {
            const value = field.split('=')[1];
            field = field.split('=')[0].toUpperCase();
            if (!this.hasOwnProperty(field))
                this[field] = new VorbisComment();
            if (!this[field].some(storedValue=> storedValue===value))
                this[field].push(value.toString());
            return this;
        }
        toStringArray() {
            const array = [];
            Object.keys(this).sort().forEach(key=> {
                this[key].forEach(value=> {
                    array.push(key+'='+value);
                });
            });
            return array;
        }
    }

    class FLACMetadataBlockData {}

    class FLACMetadataBlock {
        constructor() {
            this.blockType = '';
            this.blockTypeNubmer = 0;
            this.blockSize = 0;
            this.data = new FLACMetadataBlockData();
            this.offset = 0;
        }
        get serializedSize() {
            switch (this.blockType) {
                case 'STREAMINFO': return 34;
                case 'PADDING': return this.blockSize;
                case 'APPLICATION': return 4+this.data.applicationData.length;
                case 'SEEKTABLE': return this.data.points.length*18;
                case 'VORBIS_COMMENT':
                    const totl = this.data.comments.toStringArray().reduce((sum, str)=>sum+4+str.toUTF8().length, 0);
                    return 4+this.data.vendorString.length+4+ totl;
                case 'CUESHEET': return 0;
                case 'PICTURE': return 4+4+this.data.MIMEType.toUTF8().length+4+this.data.description.toUTF8().length+4+4+4+4+4+this.data.data.length;
            }
        }
    }

    class FLACMetadataBlocks extends Array {}

    class FLACMetadata {
        constructor() {
            this.blocks = new FLACMetadataBlocks();
            this.framesOffset = 0;
            this.signature = '';
        }
    }

    class _FLACMetadataEditor {
        get scriptVersion() {return _version;}

        constructor(buffer) {
            if (!buffer || typeof buffer !== 'object' || !('byteLength' in buffer)) {
                throw new Error('First argument should be an instance of ArrayBuffer or Buffer');
            }

            this.arrayBuffer = buffer;
            this.metadata = new FLACMetadata();

            String.prototype.toUTF8 = function(str = null) {
                return new TextEncoder().encode(str ? str : this);
            };

            this._parseMetadata();

            return this;
        }

        /* unpack */
        _getBytesAsNumber            (array, start=0, end=array.length-start) {return Array.from(array.subarray(start, start+end)).reduce     ((result, b)=>result=256*result+b, 0);}
        _getBytesAsNumberLittleEndian(array, start=0, end=array.length-start) {return Array.from(array.subarray(start, start+end)).reduceRight((result, b)=>result=256*result+b, 0);}
        _getBytesAsHexString (array, start=0, end=array.length-start) {return Array.from(array.subarray(start, start+end)).map(n=>(n>>4).toString(16)+(n&0xF).toString(16)).join('');}
        _getBytesAsUTF8String(array, start=0, end=array.length-start) {return new TextDecoder().decode(array.subarray(start, start+end));}
        _getBlockType(number){
            switch (number) {
                case 0: return 'STREAMINFO';
                case 1: return 'PADDING';
                case 2: return 'APPLICATION';
                case 3: return 'SEEKTABLE';
                case 4: return 'VORBIS_COMMENT';
                case 5: return 'CUESHEET';
                case 6: return 'PICTURE';
                case 127: return 'invalid, to avoid confusion with a frame sync code';
                default: return 'reserved';
            }
        }
        /* pack */
        _uint32ToUint8Array(uint32) {
            const eightBitMask = 0xff;
            return [
                (uint32 >>> 24) & eightBitMask,
                (uint32 >>> 16) & eightBitMask,
                (uint32 >>> 8) & eightBitMask,
                uint32 & eightBitMask,
            ];
        }
        _uint24ToUint8Array(uint32) {
            const eightBitMask = 0xff;
            return [
                (uint32 >>> 16) & eightBitMask,
                (uint32 >>> 8) & eightBitMask,
                uint32 & eightBitMask,
            ];
        }
        _uint16ToUint8Array(uint32) {
            const eightBitMask = 0xff;
            return [
                (uint32 >>> 8) & eightBitMask,
                uint32 & eightBitMask,
            ];
        }
        _hexStringToUint8Array(str) {
            return str.replace(/(\w\w)/g,'$1,').slice(0,-1).split(',').map(s=> (parseInt(s[0],16)<<4) + parseInt(s[1],16));
        }

        get _vorbisComment() {
            const block = this.metadata.blocks.find(block=>block.blockType==='VORBIS_COMMENT');
            if (block)
                return block.data;
        }

        addComment(field, value = null) {
            if (field) {
                if (!value) {
                    const splitted = field.split('=');
                    if (!splitted[1]) return this;
                    value = splitted[1];
                    field = splitted[0];
                }
                field = field.toUpperCase();
                if (!this._vorbisComment.comments.hasOwnProperty(field))
                    this._vorbisComment.comments[field] = new VorbisComment();
                if (!this._vorbisComment.comments[field].find(storedValue=> storedValue===value))
                    this._vorbisComment.comments[field].push(value.toString());
            }
            return this;
        }
        removeComment(field = null, value = null) {
            if (!field) {
                Object.keys(this._vorbisComment.comments).forEach(key=> delete this._vorbisComment.comments[key]);
            } else {
                field = field.toUpperCase();
                if (!value) {
                    delete this._vorbisComment.comments[field];
                } else {
                    value = value.toString();
                    if (this.hasOwnProperty(field))
                        this._vorbisComment.comments[field] = this._vorbisComment.comments[field].filter(storedValue=> storedValue!==value);
                }
            }
            return this;
        }
        getComment(field) {
            return this._vorbisComment.comments[field.toUpperCase()];
        }

        addPicture(dataInput) {
            if (!dataInput.data || !dataInput.data || typeof dataInput.data !== 'object' || !('byteLength' in dataInput.data)) {
                throw new Error('Field "data" should be an instance of ArrayBuffer or Buffer');
            }
            dataInput.data = new Uint8Array(dataInput.data);

            const dataDefault = {
                APICtype: 3,
                MIMEType: 'image/jpeg',
                colorDepth: 0,
                colorNumber: 0,
                data: new Uint8Array([]),
                description: '',
                width: 0,
                height: 0,
            };

            const block = new FLACMetadataBlock();
            block.blockTypeNubmer = 6;
            block.blockType = 'PICTURE';
            for (let property in dataDefault) {
                if (dataInput[property]) {
                    block.data[property] = dataInput[property];
                } else {
                    block.data[property] = dataDefault[property];
                }
            }

            const bl = this.metadata.blocks;
            let index = bl.length;
            if (bl[bl.length-1].blockType === 'PADDING') index--;

            bl.splice(index, 0, block);
            this.metadata.blocks = bl;

            return this;
        }



        _serializeMetadataBlock(block) {
            const bytes = new Uint8Array(block.serializedSize);
            const data = block.data;
            let offset = 0;

            switch (block.blockType) {
                case 'STREAMINFO':
                    bytes.set(this._uint16ToUint8Array(data.minBlockSize));
                    offset += 2;
                    bytes.set(this._uint16ToUint8Array(data.maxBlockSize), offset);
                    offset += 2;
                    bytes.set(this._uint24ToUint8Array(data.minFrameSize), offset);
                    offset += 3;
                    bytes.set(this._uint24ToUint8Array(data.maxFrameSize), offset);
                    offset += 3;
                    bytes.set(this._uint24ToUint8Array((data.sampleRate<<4) + (data.numberOfChannels-1<<1) + (data.bitsPerSample-1>>4)), offset);
                    offset += 3;
                    bytes[offset] = ((data.bitsPerSample-1&0xF)<<4) + (Math.trunc(data.totalSamples/Math.pow(2,32))&0xF);
                    offset += 1;
                    bytes.set(this._uint32ToUint8Array(data.totalSamples), offset);
                    offset += 4;
                    bytes.set(this._hexStringToUint8Array(data.rawMD5), offset);
                    break;
                case 'PADDING':
                    break;
                case 'APPLICATION':
                    bytes.set(data.applicationID.toUTF8());
                    offset += 4;
                    bytes.set(data.applicationData, offset);
                    break;
                case 'SEEKTABLE':
                    data.points.forEach(point=> {
                        bytes.set(this._hexStringToUint8Array(point.sampleNumber), offset);
                        bytes.set(this._hexStringToUint8Array(point.offset), offset+8);
                        bytes.set(this._hexStringToUint8Array(point.numberOfSamples), offset+16);
                        offset += 18;
                    });
                    break;
                case 'VORBIS_COMMENT':
                    bytes.set(this._uint32ToUint8Array(data.vendorString.toUTF8().length).reverse(), offset);
                    offset += 4;
                    bytes.set(data.vendorString.toUTF8(), offset);
                    offset += data.vendorString.toUTF8().length;

                    const comments = data.comments.toStringArray();
                    bytes.set(this._uint32ToUint8Array(comments.length).reverse(), offset);
                    offset += 4;
                    comments.forEach(comment=> {
                        bytes.set(this._uint32ToUint8Array(comment.toUTF8().length).reverse(), offset);
                        offset += 4;
                        bytes.set(comment.toUTF8(), offset);
                        offset += comment.toUTF8().length;
                    });
                    break;
                case 'CUESHEET':
                    break;
                case 'PICTURE':
                    bytes.set(this._uint32ToUint8Array(data.APICtype));
                    offset += 4;
                    bytes.set(this._uint32ToUint8Array(data.MIMEType.toUTF8().length), offset);
                    offset += 4;
                    bytes.set(data.MIMEType.toUTF8(), offset);
                    offset += data.MIMEType.toUTF8().length;

                    bytes.set(this._uint32ToUint8Array(data.description.toUTF8().length), offset);
                    offset += 4;
                    bytes.set(data.description.toUTF8(), offset);
                    offset += data.description.toUTF8().length;

                    bytes.set(this._uint32ToUint8Array(data.width), offset);
                    offset += 4;
                    bytes.set(this._uint32ToUint8Array(data.height), offset);
                    offset += 4;
                    bytes.set(this._uint32ToUint8Array(data.colorDepth), offset);
                    offset += 4;
                    bytes.set(this._uint32ToUint8Array(data.colorNumber), offset);
                    offset += 4;
                    bytes.set(this._uint32ToUint8Array(data.data.length), offset);
                    offset += 4;
                    bytes.set(data.data, offset);
                    break;
            }
            return bytes;
        }

        serializeMetadata() {
            const newMetadataLengthFull = 4+this.metadata.blocks.reduce((sum, block)=>sum+4+block.serializedSize, 0);
            const newSize = newMetadataLengthFull + (this.arrayBuffer.byteLength>this.metadata.framesOffset ? this.arrayBuffer.byteLength-this.metadata.framesOffset : 0);

            const bytes = new Uint8Array(newSize);
            bytes.set(this.metadata.signature.toUTF8());

            let offset = 4;
            let lastBlock = false;
            this.metadata.blocks.forEach((block, n, blocks)=>{
                if (blocks.length-1 === n) lastBlock = true;
                bytes[offset] = block.blockTypeNubmer | (lastBlock<<7);
                offset += 1;
                bytes.set(this._uint24ToUint8Array(block.serializedSize), offset);
                offset += 3;

                bytes.set(this._serializeMetadataBlock(block), offset);
                offset += block.serializedSize;
            });

            // console.info('old meta size: %d, new: %d, delta: %d', this.metadata.framesOffset, newMetadataLengthFull, Math.abs(this.metadata.framesOffset-newMetadataLengthFull) );
            // console.info('old size: %d, new: %d, delta: %d', this.arrayBuffer.byteLength, newSize, Math.abs(this.arrayBuffer.byteLength-newSize) );
            // console.info('frames size: %d, to copy: %d', this.arrayBuffer.byteLength-this.metadata.framesOffset, new Uint8Array(this.arrayBuffer).subarray(this.metadata.framesOffset).length);
            // console.info('offset: %d', offset );

            bytes.set(new Uint8Array(this.arrayBuffer).subarray(this.metadata.framesOffset), offset);

            this.arrayBuffer = bytes.buffer;
            return this;
        }


        _parseMetadataBlock(array, arrayOffset, type, size) {
            const blockData = array.subarray(arrayOffset, arrayOffset+size);
            let offset = 0;
            const data = new FLACMetadataBlockData();
            switch (type) {
                case 'STREAMINFO':
                    data.minBlockSize = this._getBytesAsNumber(blockData, offset, 2);
                    offset += 2;
                    data.maxBlockSize = this._getBytesAsNumber(blockData, offset, 2);
                    offset += 2;
                    data.minFrameSize = this._getBytesAsNumber(blockData, offset, 3);
                    offset += 3;
                    data.maxFrameSize = this._getBytesAsNumber(blockData, offset, 3);
                    offset += 3;
                    data.sampleRate = this._getBytesAsNumber(blockData, offset, 3)>>4;
                    offset += 2;
                    data.numberOfChannels = 1+ ((blockData[offset]>>1) &7);
                    data.bitsPerSample = 1+ ((1&blockData[offset]) <<4) + (blockData[offset+1]>>4);
                    offset += 1;
                    data.totalSamples = (blockData[offset]&0xF)*Math.pow(2,32) + this._getBytesAsNumber(blockData, offset+1, 4);
                    offset += 5;
                    data.rawMD5 = this._getBytesAsHexString(blockData, offset, 16).toUpperCase();
                    break;
                case 'PADDING':
                    break;
                case 'APPLICATION':
                    data.applicationID = this._getBytesAsUTF8String(blockData, offset, 4);
                    offset += 4;
                    data.applicationData = blockData.subarray(offset);
                    break;
                case 'SEEKTABLE':
                    data.pointCount = size/18;
                    data.points = [];
                    for (let i=0; i<data.pointCount; i++) {
                        data.points.push({
                            sampleNumber: this._getBytesAsHexString(blockData, offset, 8),
                            offset: this._getBytesAsHexString(blockData, offset+8, 8),
                            numberOfSamples: this._getBytesAsHexString(blockData, offset+16, 2),
                        });
                        offset += 18;
                    }
                    break;
                case 'VORBIS_COMMENT':
                    const vendorLength = this._getBytesAsNumberLittleEndian(blockData, offset, 4);
                    offset += 4;
                    data.vendorString = this._getBytesAsUTF8String(blockData, offset, vendorLength);
                    offset += vendorLength;

                    const userCommentListLength = this._getBytesAsNumberLittleEndian(blockData, offset, 4);
                    offset += 4;
                    data.comments = new VorbisCommentPacket();

                    let commentLength = 0;
                    for (let i=0; i<userCommentListLength; i++) {
                        commentLength = this._getBytesAsNumberLittleEndian(blockData, offset, 4);
                        offset += 4;
                        data.comments._addComment(this._getBytesAsUTF8String(blockData, offset, commentLength));
                        offset += commentLength;
                    }
                    break;
                case 'CUESHEET':
                    break;
                case 'PICTURE':
                    data.APICtype = this._getBytesAsNumber(blockData, offset, 4);
                    offset += 4;
                    const MIMELength = this._getBytesAsNumber(blockData, offset, 4);
                    offset += 4;
                    data.MIMEType = this._getBytesAsUTF8String(blockData, offset, MIMELength);
                    offset += MIMELength;
                    const descriptionLength = this._getBytesAsNumber(blockData, offset, 4);
                    offset += 4;
                    data.description = this._getBytesAsUTF8String(blockData, offset, descriptionLength);
                    offset += descriptionLength;
                    data.width = this._getBytesAsNumber(blockData, offset, 4);
                    offset += 4;
                    data.height = this._getBytesAsNumber(blockData, offset, 4);
                    offset += 4;
                    data.colorDepth = this._getBytesAsNumber(blockData, offset, 4);
                    offset += 4;
                    data.colorNumber = this._getBytesAsNumber(blockData, offset, 4);
                    offset += 4;
                    const binarySize = this._getBytesAsNumber(blockData, offset, 4);
                    offset += 4;
                    data.data = blockData.subarray(offset, offset+binarySize);
                    break;
            }
            return data;
        }

        _parseMetadata() {
            const bytes = new Uint8Array(this.arrayBuffer);

            this.metadata.signature = this._getBytesAsUTF8String(bytes,0,4);

            let offset = 4;
            let lastBlock = false;
            let block;

            let iteration = 0;
            while (!lastBlock && offset < bytes.length) {
                if (iteration++ > 42) throw new RangeError('Too much METADATA_BLOCKS. Looks like file corrupted');

                block = new FLACMetadataBlock();

                block.offset = offset;
                lastBlock = !!(bytes[offset] >> 7);
                block.blockTypeNubmer = bytes[offset] & 127;
                block.blockType = this._getBlockType(block.blockTypeNubmer);
                offset += 1;
                block.blockSize = this._getBytesAsNumber(bytes, offset, 3);
                offset += 3;
                block.data = this._parseMetadataBlock(bytes, offset, block.blockType, block.blockSize);
                offset += block.blockSize;

                // if (block.blockType !== 'PADDING')
                this.metadata.blocks.push(block);
            }
            this.metadata.framesOffset = offset;
            return this;
        }
    }

    return _FLACMetadataEditor;
})();