JS FLACMetadataEditor

Allows you to edit metadata of FLAC files. CO

此腳本不應該直接安裝,它是一個供其他腳本使用的函式庫。欲使用本函式庫,請在腳本 metadata 寫上: // @require https://update.gf.qytechs.cn/scripts/40545/646530/JS%20FLACMetadataEditor.js

您需要先安裝使用者腳本管理器擴展,如 TampermonkeyGreasemonkeyViolentmonkey 之後才能安裝該腳本。

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

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyViolentmonkey 後才能安裝該腳本。

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyUserscripts 後才能安裝該腳本。

你需要先安裝一款使用者腳本管理器擴展,比如 Tampermonkey,才能安裝此腳本

您需要先安裝使用者腳本管理器擴充功能後才能安裝該腳本。

(我已經安裝了使用者腳本管理器,讓我安裝!)

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

(我已經安裝了使用者樣式管理器,讓我安裝!)

/* 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;
})();