Complete rewrite.

Everything is done in the library now, Abema's go-mp4 lib no longer needed.

objects.go

@@ -0,0 +1,307 @@
+package mp4tag
+
+import "os"
+
+type ErrBoxNotPresent struct {
+    Msg  string
+}
+
+type ErrUnsupportedFtyp struct {
+    Msg  string
+}
+
+type ErrInvalidStcoSize struct {}
+
+type ErrInvalidMagic struct {}
+
+
+func (e *ErrBoxNotPresent) Error() string { 
+    return e.Msg
+}
+
+func (e *ErrUnsupportedFtyp) Error() string { 
+    return e.Msg
+}
+
+func (_ *ErrInvalidStcoSize) Error() string {
+	return "stco size is invalid"
+}
+
+func (_ *ErrInvalidMagic) Error() string {
+	return "file header is corrupted or not an mp4 file"
+}
+
+var ftyps = [8][]byte{
+	{0x4D, 0x34, 0x41, 0x20}, // M4A
+	{0x4D, 0x34, 0x42, 0x20}, // M4B
+	{0x64, 0x61, 0x73, 0x68}, // dash
+	{0x6D, 0x70, 0x34, 0x31}, // mp41
+	{0x6D, 0x70, 0x34, 0x32}, // mp42
+	{0x69, 0x73, 0x6F, 0x6D}, // isom
+	{0x69, 0x73, 0x6F, 0x32}, // iso2
+	{0x61, 0x76, 0x63, 0x31}, // avc1
+}
+
+var containers = []string{
+  "moov", "udta", "meta", "ilst", "----", "(c)alb",
+  "aART", "(c)art", "(c)nam", "(c)cmt", "(c)gen", "gnre",
+  "(c)wrt", "(c)con", "cprt", "desc", "(c)lyr", "(c)nrt",
+  "(c)pub", "trkn", "covr", "(c)day", "disk", "(c)too",
+  "trak", "mdia", "minf", "stbl", "rtng", "plID",
+  "atID", "tmpo", "sonm", "soal", "soar", "soco",
+  "soaa",
+}
+
+// 0-9
+var numbers = []rune{
+	0x30, 0x31, 0x32, 0x33, 0x34,
+	0x35, 0x36, 0x37, 0x38, 0x39,
+}
+
+type MP4 struct {
+	f *os.File
+	path string
+	size int64
+}
+
+type MP4Box struct {
+	StartOffset int64
+	EndOffset   int64
+	BoxSize     int64
+	Path        string
+}
+
+type MP4Boxes struct {
+	Boxes []*MP4Box
+}
+
+type ImageType int8
+const (
+	ImageTypeJPEG ImageType = iota + 13
+	ImageTypePNG
+	ImageTypeAuto
+)
+
+var resolveImageType = map[uint8]ImageType{
+	13: ImageTypeJPEG,
+	14: ImageTypePNG,
+}
+
+type ItunesAdvisory int8
+const (
+	ItunesAdvisoryNone ItunesAdvisory = iota
+	ItunesAdvisoryExplicit
+	ItunesAdvisoryClean
+)
+
+var resolveItunesAdvisory = map[uint8]ItunesAdvisory{
+	1: ItunesAdvisoryExplicit,
+	2: ItunesAdvisoryClean,
+}
+
+// GenreNone
+type Genre int8
+const (
+	GenreNone Genre = iota
+	GenreBlues
+	GenreClassicRock
+	GenreCountry
+	GenreDance
+	GenreDisco
+	GenreFunk
+	GenreGrunge
+	GenreHipHop
+	GenreJazz
+	GenreMetal
+	GenreNewAge
+	GenreOldies
+	GenreOther
+	GenrePop
+	GenreRhythmAndBlues
+	GenreRap
+	GenreReggae
+	GenreRock
+	GenreTechno
+	GenreIndustrial
+	GenreAlternative
+	GenreSka
+	GenreDeathMetal
+	GenrePranks
+	GenreSoundtrack
+	GenreEurotechno
+	GenreAmbient
+	GenreTripHop
+	GenreVocal
+	GenreJassAndFunk
+	GenreFusion
+	GenreTrance
+	GenreClassical
+	GenreInstrumental
+	GenreAcid
+	GenreHouse
+	GenreGame
+	GenreSoundClip
+	GenreGospel
+	GenreNoise
+	GenreAlternativeRock
+	GenreBass
+	GenreSoul
+	GenrePunk
+	GenreSpace
+	GenreMeditative
+	GenreInstrumentalPop
+	GenreInstrumentalRock
+	GenreEthnic
+	GenreGothic
+	GenreDarkwave
+	GenreTechnoindustrial
+	GenreElectronic
+	GenrePopFolk
+	GenreEurodance
+	GenreSouthernRock
+	GenreComedy
+	GenreCull
+	GenreGangsta
+	GenreTop40
+	GenreChristianRap
+	GenrePopSlashFunk
+	GenreJungleMusic
+	GenreNativeUS
+	GenreCabaret
+	GenreNewWave
+	GenrePsychedelic
+	GenreRave
+	GenreShowtunes
+	GenreTrailer
+	GenreLofi
+	GenreTribal
+	GenreAcidPunk
+	GenreAcidJazz
+	GenrePolka
+	GenreRetro
+	GenreMusical
+	GenreRockNRoll
+	GenreHardRock
+)
+
+var resolveGenre = map[uint8]Genre{
+	1: GenreBlues,
+	2: GenreClassicRock,
+	3: GenreCountry,
+	4: GenreDance,
+	5: GenreDisco,
+	6: GenreFunk,
+	7: GenreGrunge,
+	8: GenreHipHop,
+	9: GenreJazz,
+	10: GenreMetal,
+	11: GenreNewAge,
+	12: GenreOldies,
+	13: GenreOther,
+	14: GenrePop,
+	15: GenreRhythmAndBlues,
+	16: GenreRap,
+	17: GenreReggae,
+	18: GenreRock,
+	19: GenreTechno,
+	20: GenreIndustrial,
+	21: GenreAlternative,
+	22: GenreSka,
+	23: GenreDeathMetal,
+	24: GenrePranks,
+	25: GenreSoundtrack,
+	26: GenreEurotechno,
+	27: GenreAmbient,
+	28: GenreTripHop,
+	29: GenreVocal,
+	30: GenreJassAndFunk,
+	31: GenreFusion,
+	32: GenreTrance,
+	33: GenreClassical,
+	34: GenreInstrumental,
+	35: GenreAcid,
+	36: GenreHouse,
+	37: GenreGame,
+	38: GenreSoundClip,
+	39: GenreGospel,
+	40: GenreNoise,
+	41: GenreAlternativeRock,
+	42: GenreBass,
+	43: GenreSoul,
+	44: GenrePunk,
+	45: GenreSpace,
+	46: GenreMeditative,
+	47: GenreInstrumentalPop,
+	48: GenreInstrumentalRock,
+	49: GenreEthnic,
+	50: GenreGothic,
+	51: GenreDarkwave,
+	52: GenreTechnoindustrial,
+	53: GenreElectronic,
+	54: GenrePopFolk,
+	55: GenreEurodance,
+	56: GenreSouthernRock,
+	57: GenreComedy,
+	58: GenreCull,
+	59: GenreGangsta,
+	60: GenreTop40,
+	61: GenreChristianRap,
+	62: GenrePopSlashFunk,
+	63: GenreJungleMusic,
+	64: GenreNativeUS,
+	65: GenreCabaret,
+	66: GenreNewWave,
+	67: GenrePsychedelic,
+	68: GenreRave,
+	69: GenreShowtunes,
+	70: GenreTrailer,
+	71: GenreLofi,
+	72: GenreTribal,
+	73: GenreAcidPunk,
+	74: GenreAcidJazz,
+	75: GenrePolka,
+	76: GenreRetro,
+	77: GenreMusical,
+	78: GenreRockNRoll,
+	79: GenreHardRock,
+}
+
+type MP4Picture struct {
+	Format ImageType
+	Data []byte
+}
+
+type MP4Tags struct {
+	Album string
+	AlbumSort string 
+	AlbumArtist string
+	AlbumArtistSort string
+	Artist string
+	ArtistSort string
+	BPM int16
+	Comment string
+	Composer string
+	ComposerSort string
+	Conductor string
+	Copyright string
+	Custom map[string]string
+	CustomGenre string
+	Date string
+	Description string
+	Director string
+	DiscNumber int16
+	DiscTotal int16
+	Genre Genre
+	ItunesAdvisory ItunesAdvisory
+	ItunesAlbumID int32
+	ItunesArtistID int32
+	Lyrics string
+	Narrator string
+	Pictures []*MP4Picture
+	Publisher string
+	Title string
+	TitleSort string
+	TrackNumber int16
+	TrackTotal int16
+	Year int32
+}