package id3 // https://id3.org/id3v2.3.0 // https://id3.org/id3v2.4.0-structure // https://id3.org/id3v2.4.0-frames // https://id3.org/id3v2-chapters-1.0 import ( "io" "strings" "github.com/wader/fq/format" "github.com/wader/fq/format/registry" "github.com/wader/fq/pkg/decode" "github.com/wader/fq/pkg/scalar" "golang.org/x/text/encoding" "golang.org/x/text/encoding/charmap" "golang.org/x/text/encoding/unicode" ) var imageFormat decode.Group func init() { registry.MustRegister(decode.Format{ Name: format.ID3V2, Description: "ID3v2 metadata", DecodeFn: id3v2Decode, Dependencies: []decode.Dependency{ {Names: []string{format.IMAGE}, Group: &imageFormat}, }, }) } var idDescriptions = scalar.StrToScalar{ "BUF": {Description: "Recommended buffer size"}, "CNT": {Description: "Play counter"}, "COM": {Description: "Comments"}, "CRA": {Description: "Audio encryption"}, "CRM": {Description: "Encrypted meta frame"}, "EQU": {Description: "Equalization"}, "ETC": {Description: "Event timing codes"}, "GEO": {Description: "General encapsulated object"}, "IPL": {Description: "Involved people list"}, "LNK": {Description: "Linked information"}, "MCI": {Description: "Music CD Identifier"}, "MLL": {Description: "MPEG location lookup table"}, "PIC": {Description: "Attached picture"}, "POP": {Description: "Popularimeter"}, "REV": {Description: "Reverb"}, "RVA": {Description: "Relative volume adjustment"}, "SLT": {Description: "Synchronized lyric/text"}, "STC": {Description: "Synced tempo codes"}, "TAL": {Description: "Album/Movie/Show title"}, "TBP": {Description: "BPM (Beats Per Minute)"}, "TCM": {Description: "Composer"}, "TCO": {Description: "Content type"}, "TCR": {Description: "Copyright message"}, "TDA": {Description: "Date"}, "TDY": {Description: "Playlist delay"}, "TEN": {Description: "Encoded by"}, "TFT": {Description: "File type"}, "TIM": {Description: "Time"}, "TKE": {Description: "Initial key"}, "TLA": {Description: "Language(s)"}, "TLE": {Description: "Length"}, "TMT": {Description: "Media type"}, "TOA": {Description: "Original artist(s)/performer(s)"}, "TOF": {Description: "Original filename"}, "TOL": {Description: "Original Lyricist(s)/text writer(s)"}, "TOR": {Description: "Original release year"}, "TOT": {Description: "Original album/Movie/Show title"}, "TP1": {Description: "Lead artist(s)/Lead performer(s)/Soloist(s)/Performing group"}, "TP2": {Description: "Band/Orchestra/Accompaniment"}, "TP3": {Description: "Conductor/Performer refinement"}, "TP4": {Description: "Interpreted, remixed, or otherwise modified by"}, "TPA": {Description: "Part of a set"}, "TPB": {Description: "Publisher"}, "TRC": {Description: "ISRC (International Standard Recording Code)"}, "TRD": {Description: "Recording dates"}, "TRK": {Description: "Track number/Position in set"}, "TSI": {Description: "Size"}, "TSS": {Description: "Software/hardware and settings used for encoding"}, "TT1": {Description: "Content group description"}, "TT2": {Description: "Title/Songname/Content description"}, "TT3": {Description: "Subtitle/Description refinement"}, "TXT": {Description: "Lyricist/text writer"}, "TXX": {Description: "User defined text information frame"}, "TYE": {Description: "Year"}, "UFI": {Description: "Unique file identifier"}, "ULT": {Description: "Unsychronized lyric/text transcription"}, "WAF": {Description: "Official audio file webpage"}, "WAR": {Description: "Official artist/performer webpage"}, "WAS": {Description: "Official audio source webpage"}, "WCM": {Description: "Commercial information"}, "WCP": {Description: "Copyright/Legal information"}, "WPB": {Description: "Publishers official webpage"}, "WXX": {Description: "User defined URL link frame"}, "AENC": {Description: "Audio encryption"}, "APIC": {Description: "Attached picture"}, "ASPI": {Description: "Audio seek point index"}, "CHAP": {Description: "Chapter"}, "COMM": {Description: "Comments"}, "COMR": {Description: "Commercial frame"}, "CTOC": {Description: "Table of contents"}, "ENCR": {Description: "Encryption method registration"}, "EQU2": {Description: "Equalisation (2)"}, "EQUA": {Description: "Equalization"}, "ETCO": {Description: "Event timing codes"}, "GEOB": {Description: "General encapsulated object"}, "GRID": {Description: "Group identification registration"}, "IPLS": {Description: "Involved people list"}, "LINK": {Description: "Linked information"}, "MCDI": {Description: "Music CD identifier"}, "MLLT": {Description: "MPEG location lookup table"}, "OWNE": {Description: "Ownership frame"}, "PCNT": {Description: "Play counter"}, "POPM": {Description: "Popularimeter"}, "POSS": {Description: "Position synchronisation frame"}, "PRIV": {Description: "Private frame"}, "RBUF": {Description: "Recommended buffer size"}, "RVA2": {Description: "Relative volume adjustment (2)"}, "RVAD": {Description: "Relative volume adjustment"}, "RVRB": {Description: "Reverb"}, "SEEK": {Description: "Seek frame"}, "SIGN": {Description: "Signature frame"}, "SYLT": {Description: "Synchronized lyric/text"}, "SYTC": {Description: "Synchronized tempo codes"}, "TALB": {Description: "Album/Movie/Show title"}, "TBPM": {Description: "BPM (beats per minute)"}, "TCOM": {Description: "Composer"}, "TCON": {Description: "Content type"}, "TCOP": {Description: "Copyright message"}, "TDAT": {Description: "Date"}, "TDEN": {Description: "Encoding time"}, "TDLY": {Description: "Playlist delay"}, "TDOR": {Description: "Original release time"}, "TDRC": {Description: "Recording time"}, "TDRL": {Description: "Release time"}, "TDTG": {Description: "Tagging time"}, "TENC": {Description: "Encoded by"}, "TEXT": {Description: "Lyricist/Text writer"}, "TFLT": {Description: "File type"}, "TIME": {Description: "Time"}, "TIPL": {Description: "Involved people list"}, "TIT1": {Description: "Content group description"}, "TIT2": {Description: "Title/songname/content description"}, "TIT3": {Description: "Subtitle/Description refinement"}, "TKEY": {Description: "Initial key"}, "TLAN": {Description: "Language(s)"}, "TLEN": {Description: "Length"}, "TMCL": {Description: "Musician credits list"}, "TMED": {Description: "Media type"}, "TMOO": {Description: "Mood"}, "TOAL": {Description: "Original album/movie/show title"}, "TOFN": {Description: "Original filename"}, "TOLY": {Description: "Original lyricist(s)/text writer(s)"}, "TOPE": {Description: "Original artist(s)/performer(s)"}, "TORY": {Description: "Original release year"}, "TOWN": {Description: "File owner/licensee"}, "TPE1": {Description: "Lead performer(s)/Soloist(s)"}, "TPE2": {Description: "Band/orchestra/accompaniment"}, "TPE3": {Description: "Conductor/performer refinement"}, "TPE4": {Description: "Interpreted, remixed, or otherwise modified by"}, "TPOS": {Description: "Part of a set"}, "TPRO": {Description: "Produced notice"}, "TPUB": {Description: "Publisher"}, "TRCK": {Description: "Track number/Position in set"}, "TRDA": {Description: "Recording dates"}, "TRSN": {Description: "Internet radio station name"}, "TRSO": {Description: "Internet radio station owner"}, "TSIZ": {Description: "Size"}, "TSOA": {Description: "Album sort order"}, "TSOP": {Description: "Performer sort order"}, "TSOT": {Description: "Title sort order"}, "TSRC": {Description: "ISRC (international standard recording code)"}, "TSSE": {Description: "Software/Hardware and settings used for encoding"}, "TSST": {Description: "Set subtitle"}, "TXXX": {Description: "User defined text information frame"}, "TYER": {Description: "Year"}, "UFID": {Description: "Unique file identifier"}, "USER": {Description: "Terms of use"}, "USLT": {Description: "Unsychronized lyric/text transcription"}, "WCOM": {Description: "Commercial information"}, "WCOP": {Description: "Copyright/Legal information"}, "WOAF": {Description: "Official audio file webpage"}, "WOAR": {Description: "Official artist/performer webpage"}, "WOAS": {Description: "Official audio source webpage"}, "WORS": {Description: "Official Internet radio station homepage"}, "WPAY": {Description: "Payment"}, "WPUB": {Description: "Publishers official webpage"}, "WXXX": {Description: "User defined URL link frame"}, } // id3v2 MPEG/AAC unsynchronisation reader // Replace 0xff 0x00 0xab with 0xff 0xab in byte stream type unsyncReader struct { io.Reader lastFF bool } func (r unsyncReader) Read(p []byte) (n int, err error) { n, err = r.Reader.Read(p) ni := 0 for i, b := range p[0:n] { if r.lastFF && b == 0x00 { n-- r.lastFF = false continue } else { r.lastFF = b == 0xff } p[ni] = p[i] ni++ } return n, err } const ( encodingISO8859_1 = 0 encodingUTF16 = 1 encodingUTF16BE = 2 encodingUTF8 = 3 ) // $00 ISO-8859-1 [ISO-8859-1]. Terminated with $00. // $01 UTF-16 [UTF-16] encoded Unicode [UNICODE] with BOM. All // strings in the same frame SHALL have the same byteorder. // Terminated with $00 00. // $02 UTF-16BE [UTF-16] encoded Unicode [UNICODE] without BOM. // Terminated with $00 00. // $03 UTF-8 [UTF-8] encoded Unicode [UNICODE]. Terminated with $00. var encodingNames = scalar.UToSymStr{ encodingISO8859_1: "ISO-8859-1", encodingUTF16: "UTF-16", encodingUTF16BE: "UTF-16BE", encodingUTF8: "UTF-8", } var encodingLen = map[uint64]int64{ encodingISO8859_1: 1, encodingUTF16: 2, encodingUTF16BE: 2, encodingUTF8: 1, } func decodeToString(e int, b []byte) string { var enc encoding.Encoding switch e { case encodingISO8859_1: enc = charmap.ISO8859_1 case encodingUTF16: enc = unicode.UTF16(unicode.LittleEndian, unicode.UseBOM) case encodingUTF16BE: enc = unicode.UTF16(unicode.BigEndian, unicode.IgnoreBOM) default: enc = unicode.UTF8 } // TODO: try decode? s, _ := enc.NewDecoder().String(string(b)) return s } func decodeSyncSafeU32(d *decode.D) uint64 { u := d.U32() // syncsafe integer is a number encoded // with 8th bit in each byte set to zero // 0aaaaaaa0bbbbbbb0ccccccc0ddddddd -> // 0000aaaaaaabbbbbbbcccccccddddddd return (((u & 0x7f000000) >> 3) | ((u & 0x007f0000) >> 2) | ((u & 0x00007f00) >> 1) | ((u & 0x0000007f) >> 0)) } func textFn(encoding int, nBytes int) func(d *decode.D) string { return func(d *decode.D) string { return strings.TrimRight(decodeToString(encoding, d.BytesLen(nBytes)), "\x00") } } func textNullFn(encoding int) func(d *decode.D) string { return func(d *decode.D) string { nullLen := encodingLen[encodingUTF8] if n, ok := encodingLen[uint64(encoding)]; ok { nullLen = n } offset, _ := d.PeekFind( int(nullLen)*8, nullLen*8, func(v uint64) bool { return v == 0 }, -1, ) offsetBytes := offset / 8 text := textFn(encoding, int(offsetBytes))(d) d.SeekRel(nullLen * 8) // seems sometimes utf16 etc has en exta null byte if nullLen > 1 && d.PeekBits(8) == 0 { d.SeekRel(8) } return text } } func decodeFrame(d *decode.D, version int) uint64 { var id string var size uint64 var dataSize uint64 // TODO: global tag unsync? unsyncFlag := false switch version { case 2: // Frame ID "XXX" // Frame size $xx xx xx id = d.FieldUTF8("id", 3, idDescriptions) dataSize = d.FieldU24("size") size = dataSize + 6 case 3: // Frame ID $xx xx xx xx (four characters) // Size $xx xx xx xx // Flags $xx xx id = d.FieldUTF8("id", 4, idDescriptions) dataSize = d.FieldU32("size") d.FieldStruct("flags", func(d *decode.D) { // %abc00000 %ijk00000 d.FieldBool("tag_alter_preservation") d.FieldBool("file_alter_preservation") d.FieldBool("read_only") d.FieldU5("unused0") d.FieldBool("compression") // TODO: read encryption byte, skip decode of frame data? d.FieldBool("encryption") d.FieldBool("grouping_identity") d.FieldU5("unused1") }) size = dataSize + 10 case 4: // Frame ID $xx xx xx xx (four characters) // Size 4 * %0xxxxxxx (synchsafe integer) // Flags $xx xx id = d.FieldUTF8("id", 4, idDescriptions) dataSize = d.FieldUFn("size", decodeSyncSafeU32) var headerLen uint64 = 10 dataLenFlag := false d.FieldStruct("flags", func(d *decode.D) { // %0abc0000 %0h00kmnp d.FieldU1("unused0") d.FieldBool("tag_alter_preservation") d.FieldBool("file_alter_preservation") d.FieldBool("read_only") d.FieldU5("unused1") d.FieldBool("grouping_identity") d.FieldU2("unused2") d.FieldBool("compression") // TODO: read encryption byte, skip decode of frame data? d.FieldBool("encryption") unsyncFlag = d.FieldBool("unsync") dataLenFlag = d.FieldBool("data_length_indicator") }) if dataLenFlag { d.FieldUFn("data_length_indicator", decodeSyncSafeU32) dataSize -= 4 headerLen += 4 } size = dataSize + headerLen default: // can't know size d.Fatalf("unknown version") } // note frame function run inside a SubLenFn so they can use BitLefts and // can't accidentally read too far frames := map[string]func(d *decode.D){ // (10 bytes) // Element ID $00 // Start time $xx xx xx xx // End time $xx xx xx xx // Start offset $xx xx xx xx // End offset $xx xx xx xx // "CHAP": func(d *decode.D) { d.FieldStrFn("element_id", textNullFn(encodingUTF8)) d.FieldU32("start_time") d.FieldU32("end_time") d.FieldU32("start_offset") d.FieldU32("end_offset") decodeFrames(d, version, uint64(d.BitsLeft()/8)) }, "CTOC": func(d *decode.D) { d.FieldStrFn("element_id", textNullFn(encodingUTF8)) d.FieldU8("ctoc_flags") entryCount := d.FieldU8("entry_count") d.FieldArray("entries", func(d *decode.D) { for i := uint64(0); i < entryCount; i++ { d.FieldStrFn("entry", textNullFn(encodingUTF8)) } }) }, //
// Text encoding $xx // MIME type $00 // Picture type $xx // Description $00 (00) // Picture data "APIC": func(d *decode.D) { encoding := d.FieldU8("text_encoding", encodingNames) d.FieldStrFn("mime_type", textNullFn(encodingUTF8)) d.FieldU8("picture_type") // TODO: table d.FieldStrFn("description", textNullFn(int(encoding))) dv, _, _ := d.TryFieldFormatLen("picture", d.BitsLeft(), imageFormat, nil) if dv == nil { d.FieldRawLen("picture", d.BitsLeft()) } }, //
// Text encoding $xx // MIME type $00 // Filename $00 (00) // Content description $00 (00) // Encapsulated object "GEOB": func(d *decode.D) { encoding := d.FieldU8("text_encoding", encodingNames) d.FieldStrFn("mime_type", textNullFn(encodingUTF8)) d.FieldStrFn("filename", textNullFn(int(encoding))) d.FieldStrFn("description", textNullFn(int(encoding))) dv, _, _ := d.TryFieldFormatLen("data", d.BitsLeft(), imageFormat, nil) if dv == nil { d.FieldRawLen("data", d.BitsLeft()) } }, // Unsynced lyrics/text "ULT" // Frame size $xx xx xx // Text encoding $xx // Language $xx xx xx // Content descriptor $00 (00) // Lyrics/text // //
// Text encoding $xx // Language $xx xx xx // Content descriptor $00 (00) // Lyrics/text // // Comment "COM" // Frame size $xx xx xx // Text encoding $xx // Language $xx xx xx // Short content description $00 (00) // The actual text // //
// Text encoding $xx // Language $xx xx xx // Short content descrip. $00 (00) // The actual text "COMM": func(d *decode.D) { encoding := d.FieldU8("text_encoding", encodingNames) d.FieldUTF8("language", 3) d.FieldStrFn("description", textNullFn(int(encoding))) d.FieldStrFn("value", textFn(int(encoding), int(d.BitsLeft()/8))) }, // Text information identifier "T00" - "TZZ" , excluding "TXX", // described in 4.2.2. // Frame size $xx xx xx // Text encoding $xx // Information // //
// Text encoding $xx // Information "T000": func(d *decode.D) { encoding := d.FieldU8("text_encoding", encodingNames) d.FieldStrFn("text", textFn(int(encoding), int(d.BitsLeft()/8))) }, // User defined... "TXX" // Frame size $xx xx xx // Text encoding $xx // Description $00 (00) // Value // //
// Text encoding $xx // Description $00 (00) // Value "TXXX": func(d *decode.D) { encoding := d.FieldU8("text_encoding", encodingNames) d.FieldStrFn("description", textNullFn(int(encoding))) d.FieldStrFn("value", textFn(int(encoding), int(d.BitsLeft()/8))) }, //
// Owner identifier $00 // The private data "PRIV": func(d *decode.D) { // TODO: is default ISO8859-1? d.FieldStrFn("owner", textNullFn(int(encodingISO8859_1))) d.FieldRawLen("data", d.BitsLeft()) }, } idNormalized := id switch { case id == "COMM", id == "COM", id == "USLT", id == "ULT": idNormalized = "COMM" case id == "TXX", id == "TXXX": idNormalized = "TXXX" case len(id) > 0 && id[0] == 'T': idNormalized = "T000" } if unsyncFlag { // TODO: DecodeFn // TODO: unknown after frame decode unsyncedBb := d.MustNewBitBufFromReader(unsyncReader{Reader: d.BitBufRange(d.Pos(), int64(dataSize)*8)}) d.FieldFormatBitBuf("unsync", unsyncedBb, decode.FormatFn(func(d *decode.D, in interface{}) interface{} { if fn, ok := frames[idNormalized]; ok { fn(d) } else { d.FieldRawLen("data", d.BitsLeft()) } return nil }), nil) d.FieldRawLen("data", int64(dataSize*8)) } else { if fn, ok := frames[idNormalized]; ok { d.LenFn(int64(dataSize)*8, func(d *decode.D) { fn(d) }) } else { d.FieldRawLen("data", int64(dataSize*8)) } } return size } func decodeFrames(d *decode.D, version int, size uint64) { d.FieldArray("frames", func(d *decode.D) { for size > 0 { if d.PeekBits(8) == 0 { return } d.FieldStruct("frame", func(d *decode.D) { size -= decodeFrame(d, version) }) } }) if size > 0 { d.FieldRawLen("padding", int64(size*8), d.BitBufIsZero()) } } func id3v2Decode(d *decode.D, in interface{}) interface{} { d.AssertAtLeastBitsLeft(4 * 8) d.FieldUTF8("magic", 3, d.ValidateStr("ID3")) version := int(d.FieldU8("version")) versionValid := version == 2 || version == 3 || version == 4 if !versionValid { d.Fatalf("unsupported version %d", version) } d.FieldU8("revision") var extendedHeader bool d.FieldStruct("flags", func(d *decode.D) { d.FieldBool("unsynchronisation") extendedHeader = d.FieldBool("extended_header") d.FieldBool("experimental_indicator") d.FieldU5("unused") }) size := d.FieldUFn("size", decodeSyncSafeU32) var extHeaderSize uint64 if extendedHeader { d.FieldStruct("extended_header", func(d *decode.D) { switch version { case 3: extHeaderSize = d.FieldU32("size") d.FieldRawLen("data", int64(extHeaderSize)*8) case 4: extHeaderSize = d.FieldUFn("size", decodeSyncSafeU32) // in v4 synchsafe integer includes itself d.FieldRawLen("data", (int64(extHeaderSize)-4)*8) } }) } decodeFrames(d, version, size) return nil }