mirror of
https://github.com/wader/fq.git
synced 2024-11-27 14:14:58 +03:00
8e0dde03d0
This will allow passing both cli options and format options to sub decoder. Ex: pass keylog option to a tls decoder when decoding a pcap. Ex: pass decode options to a format inside a http body inside a pcap. Add ArgAs method to lookup argument based on type. This also makes the format decode function have same signature as sub decoders in the decode API. This change decode.Format a bit: DecodeFn is now just func(d *D) any DecodeInArg renamed to DefaultInArg
647 lines
19 KiB
Go
647 lines
19 KiB
Go
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/pkg/bitio"
|
|
"github.com/wader/fq/pkg/decode"
|
|
"github.com/wader/fq/pkg/interp"
|
|
"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() {
|
|
interp.RegisterFormat(decode.Format{
|
|
Name: format.ID3V2,
|
|
Description: "ID3v2 metadata",
|
|
DecodeFn: id3v2Decode,
|
|
Dependencies: []decode.Dependency{
|
|
{Names: []string{format.IMAGE}, Group: &imageFormat},
|
|
},
|
|
})
|
|
}
|
|
|
|
var idDescriptions = scalar.StrMapDescription{
|
|
"BUF": "Recommended buffer size",
|
|
"CNT": "Play counter",
|
|
"COM": "Comments",
|
|
"CRA": "Audio encryption",
|
|
"CRM": "Encrypted meta frame",
|
|
"EQU": "Equalization",
|
|
"ETC": "Event timing codes",
|
|
"GEO": "General encapsulated object",
|
|
"IPL": "Involved people list",
|
|
"LNK": "Linked information",
|
|
"MCI": "Music CD Identifier",
|
|
"MLL": "MPEG location lookup table",
|
|
"PIC": "Attached picture",
|
|
"POP": "Popularimeter",
|
|
"REV": "Reverb",
|
|
"RVA": "Relative volume adjustment",
|
|
"SLT": "Synchronized lyric/text",
|
|
"STC": "Synced tempo codes",
|
|
"TAL": "Album/Movie/Show title",
|
|
"TBP": "BPM (Beats Per Minute)",
|
|
"TCM": "Composer",
|
|
"TCO": "Content type",
|
|
"TCR": "Copyright message",
|
|
"TDA": "Date",
|
|
"TDY": "Playlist delay",
|
|
"TEN": "Encoded by",
|
|
"TFT": "File type",
|
|
"TIM": "Time",
|
|
"TKE": "Initial key",
|
|
"TLA": "Language(s)",
|
|
"TLE": "Length",
|
|
"TMT": "Media type",
|
|
"TOA": "Original artist(s)/performer(s)",
|
|
"TOF": "Original filename",
|
|
"TOL": "Original Lyricist(s)/text writer(s)",
|
|
"TOR": "Original release year",
|
|
"TOT": "Original album/Movie/Show title",
|
|
"TP1": "Lead artist(s)/Lead performer(s)/Soloist(s)/Performing group",
|
|
"TP2": "Band/Orchestra/Accompaniment",
|
|
"TP3": "Conductor/Performer refinement",
|
|
"TP4": "Interpreted, remixed, or otherwise modified by",
|
|
"TPA": "Part of a set",
|
|
"TPB": "Publisher",
|
|
"TRC": "ISRC (International Standard Recording Code)",
|
|
"TRD": "Recording dates",
|
|
"TRK": "Track number/Position in set",
|
|
"TSI": "Size",
|
|
"TSS": "Software/hardware and settings used for encoding",
|
|
"TT1": "Content group description",
|
|
"TT2": "Title/Songname/Content description",
|
|
"TT3": "Subtitle/Description refinement",
|
|
"TXT": "Lyricist/text writer",
|
|
"TXX": "User defined text information frame",
|
|
"TYE": "Year",
|
|
"UFI": "Unique file identifier",
|
|
"ULT": "Unsychronized lyric/text transcription",
|
|
"WAF": "Official audio file webpage",
|
|
"WAR": "Official artist/performer webpage",
|
|
"WAS": "Official audio source webpage",
|
|
"WCM": "Commercial information",
|
|
"WCP": "Copyright/Legal information",
|
|
"WPB": "Publishers official webpage",
|
|
"WXX": "User defined URL link frame",
|
|
"AENC": "Audio encryption",
|
|
"APIC": "Attached picture",
|
|
"ASPI": "Audio seek point index",
|
|
"CHAP": "Chapter",
|
|
"COMM": "Comments",
|
|
"COMR": "Commercial frame",
|
|
"CTOC": "Table of contents",
|
|
"ENCR": "Encryption method registration",
|
|
"EQU2": "Equalisation (2)",
|
|
"EQUA": "Equalization",
|
|
"ETCO": "Event timing codes",
|
|
"GEOB": "General encapsulated object",
|
|
"GRID": "Group identification registration",
|
|
"IPLS": "Involved people list",
|
|
"LINK": "Linked information",
|
|
"MCDI": "Music CD identifier",
|
|
"MLLT": "MPEG location lookup table",
|
|
"OWNE": "Ownership frame",
|
|
"PCNT": "Play counter",
|
|
"POPM": "Popularimeter",
|
|
"POSS": "Position synchronisation frame",
|
|
"PRIV": "Private frame",
|
|
"RBUF": "Recommended buffer size",
|
|
"RVA2": "Relative volume adjustment (2)",
|
|
"RVAD": "Relative volume adjustment",
|
|
"RVRB": "Reverb",
|
|
"SEEK": "Seek frame",
|
|
"SIGN": "Signature frame",
|
|
"SYLT": "Synchronized lyric/text",
|
|
"SYTC": "Synchronized tempo codes",
|
|
"TALB": "Album/Movie/Show title",
|
|
"TBPM": "BPM (beats per minute)",
|
|
"TCOM": "Composer",
|
|
"TCON": "Content type",
|
|
"TCOP": "Copyright message",
|
|
"TDAT": "Date",
|
|
"TDEN": "Encoding time",
|
|
"TDLY": "Playlist delay",
|
|
"TDOR": "Original release time",
|
|
"TDRC": "Recording time",
|
|
"TDRL": "Release time",
|
|
"TDTG": "Tagging time",
|
|
"TENC": "Encoded by",
|
|
"TEXT": "Lyricist/Text writer",
|
|
"TFLT": "File type",
|
|
"TIME": "Time",
|
|
"TIPL": "Involved people list",
|
|
"TIT1": "Content group description",
|
|
"TIT2": "Title/songname/content description",
|
|
"TIT3": "Subtitle/Description refinement",
|
|
"TKEY": "Initial key",
|
|
"TLAN": "Language(s)",
|
|
"TLEN": "Length",
|
|
"TMCL": "Musician credits list",
|
|
"TMED": "Media type",
|
|
"TMOO": "Mood",
|
|
"TOAL": "Original album/movie/show title",
|
|
"TOFN": "Original filename",
|
|
"TOLY": "Original lyricist(s)/text writer(s)",
|
|
"TOPE": "Original artist(s)/performer(s)",
|
|
"TORY": "Original release year",
|
|
"TOWN": "File owner/licensee",
|
|
"TPE1": "Lead performer(s)/Soloist(s)",
|
|
"TPE2": "Band/orchestra/accompaniment",
|
|
"TPE3": "Conductor/performer refinement",
|
|
"TPE4": "Interpreted, remixed, or otherwise modified by",
|
|
"TPOS": "Part of a set",
|
|
"TPRO": "Produced notice",
|
|
"TPUB": "Publisher",
|
|
"TRCK": "Track number/Position in set",
|
|
"TRDA": "Recording dates",
|
|
"TRSN": "Internet radio station name",
|
|
"TRSO": "Internet radio station owner",
|
|
"TSIZ": "Size",
|
|
"TSOA": "Album sort order",
|
|
"TSOP": "Performer sort order",
|
|
"TSOT": "Title sort order",
|
|
"TSRC": "ISRC (international standard recording code)",
|
|
"TSSE": "Software/Hardware and settings used for encoding",
|
|
"TSST": "Set subtitle",
|
|
"TXXX": "User defined text information frame",
|
|
"TYER": "Year",
|
|
"UFID": "Unique file identifier",
|
|
"USER": "Terms of use",
|
|
"USLT": "Unsychronized lyric/text transcription",
|
|
"WCOM": "Commercial information",
|
|
"WCOP": "Copyright/Legal information",
|
|
"WOAF": "Official audio file webpage",
|
|
"WOAR": "Official artist/performer webpage",
|
|
"WOAS": "Official audio source webpage",
|
|
"WORS": "Official Internet radio station homepage",
|
|
"WPAY": "Payment",
|
|
"WPUB": "Publishers official webpage",
|
|
"WXXX": "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.UintMapSymStr{
|
|
encodingISO8859_1: "iso_8859-1",
|
|
encodingUTF16: "utf16",
|
|
encodingUTF16BE: "utf16be",
|
|
encodingUTF8: "utf8",
|
|
}
|
|
|
|
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 textNullLenFn(encoding int, notFoundFixedBytes 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, _, err := d.TryPeekFind(
|
|
int(nullLen)*8,
|
|
nullLen*8,
|
|
int64(notFoundFixedBytes)*8,
|
|
func(v uint64) bool { return v == 0 },
|
|
)
|
|
if err != nil {
|
|
d.IOPanic(err, "textNullLenFn")
|
|
}
|
|
if offset < 0 {
|
|
if notFoundFixedBytes < 0 {
|
|
d.Fatalf("textNullLenFn: null not found")
|
|
}
|
|
return textFn(encoding, notFoundFixedBytes)(d)
|
|
}
|
|
|
|
offsetBytes := offset / 8
|
|
text := textFn(encoding, int(offsetBytes))(d)
|
|
|
|
d.SeekRel(nullLen * 8)
|
|
// seems sometimes utf16 etc has one exta null byte
|
|
if nullLen > 1 && d.PeekBits(8) == 0 {
|
|
d.SeekRel(8)
|
|
}
|
|
|
|
return text
|
|
}
|
|
}
|
|
|
|
func textNullFn(encoding int) func(d *decode.D) string {
|
|
return textNullLenFn(encoding, -1)
|
|
}
|
|
|
|
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.FieldUintFn("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.FieldUintFn("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){
|
|
// <ID3v2.3 or ID3v2.4 frame header, ID: "CHAP"> (10 bytes)
|
|
// Element ID <text string> $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
|
|
// <Optional embedded sub-frames>
|
|
"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))
|
|
}
|
|
})
|
|
},
|
|
|
|
// id3v2.0
|
|
// Attached picture "PIC"
|
|
// Frame size $xx xx xx
|
|
// Text encoding $xx
|
|
// Image format $xx xx xx
|
|
// Picture type $xx
|
|
// Description <textstring> $00 (00)
|
|
// Picture data <binary data>
|
|
"PIC": func(d *decode.D) {
|
|
encoding := d.FieldU8("text_encoding", encodingNames)
|
|
d.FieldUTF8("image_format", 3)
|
|
d.FieldU8("picture_type") // TODO: table
|
|
d.FieldStrFn("description", textNullFn(int(encoding)))
|
|
d.FieldFormatOrRawLen("picture", d.BitsLeft(), imageFormat, nil)
|
|
},
|
|
|
|
// <Header for 'Attached picture', ID: "APIC">
|
|
// Text encoding $xx
|
|
// MIME type <text string> $00
|
|
// Picture type $xx
|
|
// Description <text string according to encoding> $00 (00)
|
|
// Picture data <binary 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)))
|
|
d.FieldFormatOrRawLen("picture", d.BitsLeft(), imageFormat, nil)
|
|
},
|
|
|
|
// <Header for 'General encapsulated object', ID: "GEOB">
|
|
// Text encoding $xx
|
|
// MIME type <text string> $00
|
|
// Filename <text string according to encoding> $00 (00)
|
|
// Content description <text string according to encoding> $00 (00)
|
|
// Encapsulated object <binary data>
|
|
"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)))
|
|
d.FieldFormatOrRawLen("data", d.BitsLeft(), imageFormat, nil)
|
|
},
|
|
|
|
// Unsynced lyrics/text "ULT"
|
|
// Frame size $xx xx xx
|
|
// Text encoding $xx
|
|
// Language $xx xx xx
|
|
// Content descriptor <textstring> $00 (00)
|
|
// Lyrics/text <textstring>
|
|
//
|
|
// <Header for 'Unsynchronised lyrics/text transcription', ID: "USLT">
|
|
// Text encoding $xx
|
|
// Language $xx xx xx
|
|
// Content descriptor <text string according to encoding> $00 (00)
|
|
// Lyrics/text <full text string according to encoding>
|
|
//
|
|
// Comment "COM"
|
|
// Frame size $xx xx xx
|
|
// Text encoding $xx
|
|
// Language $xx xx xx
|
|
// Short content description <textstring> $00 (00)
|
|
// The actual text <textstring>
|
|
//
|
|
// <Header for 'Comment', ID: "COMM">
|
|
// Text encoding $xx
|
|
// Language $xx xx xx
|
|
// Short content descrip. <text string according to encoding> $00 (00)
|
|
// The actual text <full text string according to encoding>
|
|
"COMM": func(d *decode.D) {
|
|
encoding := d.FieldU8("text_encoding", encodingNames)
|
|
d.FieldUTF8("language", 3)
|
|
// there are COMM frames with no null termination
|
|
d.FieldStrFn("description", textNullLenFn(int(encoding), int(d.BitsLeft()/8)))
|
|
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 <textstring>
|
|
//
|
|
// <Header for 'Text information frame', ID: "T000" - "TZZZ",
|
|
// excluding "TXXX" described in 4.2.6.>
|
|
// Text encoding $xx
|
|
// Information <text string(s) according to encoding>
|
|
"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 <textstring> $00 (00)
|
|
// Value <textstring>
|
|
//
|
|
// <Header for 'User defined text information frame', ID: "TXXX">
|
|
// Text encoding $xx
|
|
// Description <text string according to encoding> $00 (00)
|
|
// Value <text string according to encoding>
|
|
"TXXX": func(d *decode.D) {
|
|
encoding := d.FieldU8("text_encoding", encodingNames)
|
|
// there are TXXX frames with no null termination
|
|
d.FieldStrFn("description", textNullLenFn(int(encoding), int(d.BitsLeft()/8)))
|
|
d.FieldStrFn("value", textFn(int(encoding), int(d.BitsLeft()/8)))
|
|
},
|
|
// <Header for 'Private frame', ID: "PRIV">
|
|
// Owner identifier <text string> $00
|
|
// The private data <binary 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
|
|
unsyncedBR := d.NewBitBufFromReader(unsyncReader{Reader: bitio.NewIOReader(d.BitBufRange(d.Pos(), int64(dataSize)*8))})
|
|
d.FieldFormatBitBuf("unsync", unsyncedBR, decode.FormatFn(func(d *decode.D) any {
|
|
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.FramedFn(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) any {
|
|
d.AssertAtLeastBitsLeft(4 * 8)
|
|
d.FieldUTF8("magic", 3, d.StrAssert("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.FieldUintFn("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.FieldUintFn("size", decodeSyncSafeU32)
|
|
// in v4 synchsafe integer includes itself
|
|
d.FieldRawLen("data", (int64(extHeaderSize)-4)*8)
|
|
}
|
|
})
|
|
}
|
|
|
|
decodeFrames(d, version, size)
|
|
|
|
return nil
|
|
}
|