Zazama /
node-id3
| 1 | const iconv = require('iconv-lite') |
||
| 2 | const ID3Definitions = require('./ID3Definitions') |
||
| 3 | |||
| 4 | const ENCODINGS = [ |
||
| 5 | 'ISO-8859-1', 'UTF-16', 'UTF-16BE', 'UTF-8' |
||
| 6 | ] |
||
| 7 | |||
| 8 | module.exports.SplitBuffer = class SplitBuffer { |
||
| 9 | constructor(value = null, remainder = null) { |
||
| 10 | this.value = value |
||
| 11 | this.remainder = remainder |
||
| 12 | } |
||
| 13 | } |
||
| 14 | |||
| 15 | module.exports.splitNullTerminatedBuffer = function(buffer, encodingByte = 0x00) { |
||
| 16 | let termination = { start: -1, size: 0 } |
||
| 17 | if(encodingByte === 0x01 || encodingByte === 0x02) { |
||
| 18 | termination.start = buffer.indexOf(Buffer.from([0x00, 0x00])) |
||
| 19 | termination.size = 2 |
||
| 20 | if(termination.start !== -1 && buffer.length > (termination.start + termination.size)) { |
||
| 21 | if(buffer[termination.start + termination.size] === 0x00) { |
||
| 22 | termination.start += 1 |
||
| 23 | } |
||
| 24 | } |
||
| 25 | } else { |
||
| 26 | termination.start = buffer.indexOf(0x00) |
||
| 27 | termination.size = 1 |
||
| 28 | } |
||
| 29 | |||
| 30 | if(termination.start === -1) { |
||
| 31 | return new this.SplitBuffer(null, buffer.slice(0)) |
||
| 32 | } |
||
| 33 | else if(buffer.length <= termination.start + termination.length) { |
||
| 34 | return new this.SplitBuffer(buffer.slice(0, termination.start), null) |
||
| 35 | } else { |
||
| 36 | return new this.SplitBuffer(buffer.slice(0, termination.start), buffer.slice(termination.start + termination.size)) |
||
| 37 | } |
||
| 38 | } |
||
| 39 | |||
| 40 | module.exports.terminationBuffer = function(encodingByte = 0x00) { |
||
| 41 | if(encodingByte === 0x01 || encodingByte === 0x02) { |
||
| 42 | return Buffer.alloc(2, 0x00) |
||
| 43 | } else { |
||
| 44 | return Buffer.alloc(1, 0x00) |
||
| 45 | } |
||
| 46 | } |
||
| 47 | |||
| 48 | module.exports.encodingFromStringOrByte = function(encoding) { |
||
| 49 | if(ENCODINGS.indexOf(encoding) !== -1) { |
||
| 50 | return encoding |
||
| 51 | } else if(encoding > -1 && encoding < ENCODINGS.length) { |
||
| 52 | encoding = ENCODINGS[encoding] |
||
| 53 | } else { |
||
| 54 | encoding = ENCODINGS[0] |
||
| 55 | } |
||
| 56 | return encoding |
||
| 57 | } |
||
| 58 | |||
| 59 | module.exports.stringToEncodedBuffer = function(str, encodingByte) { |
||
| 60 | return iconv.encode(str, this.encodingFromStringOrByte(encodingByte)) |
||
| 61 | } |
||
| 62 | |||
| 63 | module.exports.bufferToDecodedString = function(buffer, encodingByte) { |
||
| 64 | return iconv.decode(buffer, this.encodingFromStringOrByte(encodingByte)).replace(/\0/g, '') |
||
| 65 | } |
||
| 66 | |||
| 67 | module.exports.getSpecOptions = function(specName, version) { |
||
| 68 | if(version === 2) { |
||
| 69 | if(ID3Definitions.ID3_FRAME_OPTIONS.v2[specName] && ID3Definitions.ID3_FRAME_OPTIONS.v2[specName]) { |
||
| 70 | return ID3Definitions.ID3_FRAME_OPTIONS.v2[specName] |
||
| 71 | } |
||
| 72 | } else if (version === 3 || version === 4) { |
||
| 73 | if(ID3Definitions.ID3_FRAME_OPTIONS.v3[specName] && ID3Definitions.ID3_FRAME_OPTIONS.v3[specName]) { |
||
| 74 | return ID3Definitions.ID3_FRAME_OPTIONS.v3[specName] |
||
| 75 | } |
||
| 76 | } |
||
| 77 | return {} |
||
| 78 | } |
||
| 79 | |||
| 80 | module.exports.isValidID3Header = function(buffer) { |
||
| 81 | if(buffer.length < 10) { |
||
| 82 | return false; |
||
| 83 | } else if(buffer.readUIntBE(0, 3) !== 0x494433) { |
||
| 84 | return false; |
||
| 85 | } else if([0x02, 0x03, 0x04].indexOf(buffer[3]) === -1 || buffer[4] !== 0x00) { |
||
| 86 | return false; |
||
| 87 | } else if(buffer[6] & 128 === 1 || buffer[7] & 128 === 1 || buffer[8] & 128 === 1 || buffer[9] & 128 === 1) { |
||
| 88 | return false; |
||
| 89 | } |
||
| 90 | return true; |
||
| 91 | }; |
||
| 92 | |||
| 93 | module.exports.getFramePosition = function(buffer) { |
||
| 94 | /* Search Buffer for valid ID3 frame */ |
||
| 95 | let framePosition = -1; |
||
| 96 | let frameHeaderValid = false; |
||
| 97 | do { |
||
| 98 | framePosition = buffer.indexOf("ID3", framePosition + 1); |
||
| 99 | if(framePosition !== -1) { |
||
| 100 | /* It's possible that there is a "ID3" sequence without being an ID3 Frame, |
||
| 101 | * so we need to check for validity of the next 10 bytes |
||
| 102 | */ |
||
| 103 | frameHeaderValid = this.isValidID3Header(buffer.slice(framePosition, framePosition + 10)); |
||
| 104 | } |
||
| 105 | } while (framePosition !== -1 && !frameHeaderValid); |
||
| 106 | |||
| 107 | if(!frameHeaderValid) { |
||
| 108 | return -1; |
||
| 109 | } else { |
||
| 110 | return framePosition; |
||
| 111 | } |
||
| 112 | } |
||
| 113 | |||
| 114 | /** |
||
| 115 | * @return {Buffer} |
||
| 116 | */ |
||
| 117 | module.exports.encodeSize = function(totalSize) { |
||
| 118 | let byte_3 = totalSize & 0x7F; |
||
| 119 | let byte_2 = (totalSize >> 7) & 0x7F; |
||
| 120 | let byte_1 = (totalSize >> 14) & 0x7F; |
||
| 121 | let byte_0 = (totalSize >> 21) & 0x7F; |
||
| 122 | return Buffer.from([byte_0, byte_1, byte_2, byte_3]); |
||
| 123 | }; |
||
| 124 | |||
| 125 | /** |
||
| 126 | * @return {Buffer} |
||
| 127 | */ |
||
| 128 | module.exports.decodeSize = function(hSize) { |
||
| 129 | return (hSize[0] << 21) + (hSize[1] << 14) + (hSize[2] << 7) + hSize[3]; |
||
| 130 | }; |
||
| 131 | |||
| 132 | module.exports.getFrameSize = function(buffer, decode, ID3Version) { |
||
| 133 | let decodeBytes |
||
| 134 | if(ID3Version > 2) { |
||
| 135 | decodeBytes = [buffer[4], buffer[5], buffer[6], buffer[7]] |
||
| 136 | } else { |
||
| 137 | decodeBytes = [buffer[3], buffer[4], buffer[5]] |
||
| 138 | } |
||
| 139 | if(decode) { |
||
| 140 | return this.decodeSize(Buffer.from(decodeBytes)) |
||
| 141 | } else { |
||
| 142 | return Buffer.from(decodeBytes).readUIntBE(0, decodeBytes.length) |
||
| 143 | } |
||
| 144 | } |
||
| 145 | |||
| 146 | module.exports.parseTagHeaderFlags = function(header) { |
||
| 147 | if(!(header instanceof Buffer && header.length >= 10)) { |
||
| 148 | return {} |
||
| 149 | } |
||
| 150 | const version = header[3] |
||
| 151 | const flagsByte = header[5] |
||
| 152 | if(version === 3) { |
||
| 153 | return { |
||
| 154 | unsynchronisation: !!(flagsByte & 128), |
||
| 155 | extendedHeader: !!(flagsByte & 64), |
||
| 156 | experimentalIndicator: !!(flagsByte & 32) |
||
| 157 | } |
||
| 158 | } |
||
| 159 | if(version === 4) { |
||
| 160 | return { |
||
| 161 | unsynchronisation: !!(flagsByte & 128), |
||
| 162 | extendedHeader: !!(flagsByte & 64), |
||
| 163 | experimentalIndicator: !!(flagsByte & 32), |
||
| 164 | footerPresent: !!(flagsByte & 16) |
||
| 165 | } |
||
| 166 | } |
||
| 167 | return {} |
||
| 168 | } |
||
| 169 | |||
| 170 | module.exports.parseFrameHeaderFlags = function(header, ID3Version) { |
||
| 171 | if(!(header instanceof Buffer && header.length === 10)) { |
||
| 172 | return {} |
||
| 173 | } |
||
| 174 | const flagsFirstByte = header[8] |
||
| 175 | const flagsSecondByte = header[9] |
||
| 176 | View Code Duplication | if(ID3Version === 3) { |
|
| 177 | return { |
||
| 178 | tagAlterPreservation: !!(flagsFirstByte & 128), |
||
| 179 | fileAlterPreservation: !!(flagsFirstByte & 64), |
||
| 180 | readOnly: !!(flagsFirstByte & 32), |
||
| 181 | compression: !!(flagsSecondByte & 128), |
||
| 182 | encryption: !!(flagsSecondByte & 64), |
||
| 183 | groupingIdentity: !!(flagsSecondByte & 32) |
||
| 184 | } |
||
| 185 | } |
||
| 186 | View Code Duplication | if(ID3Version === 4) { |
|
| 187 | return { |
||
| 188 | tagAlterPreservation: !!(flagsFirstByte & 64), |
||
| 189 | fileAlterPreservation: !!(flagsFirstByte & 32), |
||
| 190 | readOnly: !!(flagsFirstByte & 16), |
||
| 191 | groupingIdentity: !!(flagsSecondByte & 64), |
||
| 192 | compression: !!(flagsSecondByte & 8), |
||
| 193 | encryption: !!(flagsSecondByte & 4), |
||
| 194 | unsynchronisation: !!(flagsSecondByte & 2), |
||
| 195 | dataLengthIndicator: !!(flagsSecondByte & 1) |
||
| 196 | } |
||
| 197 | } |
||
| 198 | return {} |
||
| 199 | } |
||
| 200 | |||
| 201 | module.exports.processUnsynchronisedBuffer = function(buffer) { |
||
| 202 | const newDataArr = [] |
||
| 203 | if(buffer.length > 0) { |
||
| 204 | newDataArr.push(buffer[0]) |
||
| 205 | } |
||
| 206 | for(let i = 1; i < buffer.length; i++) { |
||
| 207 | if(buffer[i - 1] === 0xFF && buffer[i] === 0x00) |
||
| 208 | continue |
||
|
0 ignored issues
–
show
|
|||
| 209 | newDataArr.push(buffer[i]) |
||
| 210 | } |
||
| 211 | return Buffer.from(newDataArr) |
||
| 212 | } |
||
| 213 |
Consider adding curly braces around all statements when they are executed conditionally. This is optional if there is only one statement, but leaving them out can lead to unexpected behaviour if another statement is added later.
Consider:
If you or someone else later decides to put another statement in, only the first statement will be executed.
In this case the statement
b = 42will always be executed, while the logging statement will be executed conditionally.ensures that the proper code will be executed conditionally no matter how many statements are added or removed.