MP4-Felder (Atom/Box)

[Crissov]

Ich habe mal geguckt, welche QuickTime/MP4-Metadaten-Atoms/-Boxes andere Programme laut ihrer Doku unterstützen und sie mit Mp3tag verglichen. Möglicherweise macht es Sinn, das eine oder andere auf eine Variable und damit ggf. auch auf ein ID3-Feld zu mappen sowie ggf. die Werte aus seltener verwendeten Atoms in semantisch äquivalente zu kopieren.

FFmpeg

Für FFmpeg habe ich keine offizielle Doku gefunden, aber das Multimedia.cx-Wiki wird öfter erwähnt. Sie scheint nicht ganz aktuell und vielleicht auch nicht ganz korrekt zu sein, aber besser als gar nichts.

• Ich bin mir nicht sicher, ob die korrekte Schreibung des Feldes für das ARTIST-Atom klein ©art oder groß ©ART ist.
• Mp3tag matcht COPYRIGHT auf TCOP in ID3v2 und cprt in MP4, aber FFmpeg matcht copyright auf ©cpy.
• ©too (Tool) wird für Mp3tag nicht dokumentiert, FFmpeg speichert darin unabänderbar die libavformat-Version. Es könnte äquivalent zu ENCODEDBY (ID3: TENC) oder ENCODERSETTINGS (TSSE) sein.
• FFmpeg unterstützt offenbar nur ©gen und nicht gnre für GENRE.
• PODCASTDESC mappt auf TDES (ID3) und ldes (MP4), aber FFmpeg kennt nur letzteres als synopsis.
• YEAR steht für TYER bzw. TDRC (v2.3 vs. v2.4) und ©day, während FFmpeg date auf TDRC abbildet, aber year auf ©day und TDRL, was Mp3tag als RELEASETIME bezeichnet.

[Crissov]

FFmpeg

Field in Mp3tag	ID3v2.3/4	MP4	FFmpeg	AVI FourCC
TVEPISODEID		tven	episode_id
TVEPISODE		tves	(episode_sort)
TVSEASON		tvsn	(season_number)
DISCNUMBER	TPOS	disk	disc
TRACK	TRCK	trkn	track	IPRT
CONTENTGROUP		©grp	grouping
CONTENTGROUP	TIT1		—
TITLE	TIT2	©nam	title	INAM
TITLESORT	TSOT	sonm	title-sort, (sort_name)
TVSHOW		tvsh	show
ALBUM	TALB	©alb	album	IPRD
ALBUMSORT	TSOA	soal	album-sort, (sort_album)
ARTIST	TPE1		artist	IART
ARTIST		©art (©ART)	author
ARTISTSORT	TSOP	soar	artist-sort, (sort_artist)
ALBUMARTIST	TPE2	aART	album_artist
CONDUCTOR	TPE3	©con	performer
COMPOSER	TCOM	©wrt	composer
PUBLISHER	TPUB		publisher
TVNETWORK		tvnn	network
COPYRIGHT		cprt	—
COPYRIGHT	TCOP		copyright
—		©cpy	copyright	ICOP
ENCODEDBY	TENC		encoded_by	ITCH
—		©too	libavformat version
ENCODERSETTINGS	TSSE		encoder	ISFT
COMPILATION	TCMP	cpil	compilation
ITUNESHDVIDEO		hdvd	(hd_video)
ITUNESMEDIATYPE		stik	(media_type)
GENRE	TCON	©gen	genre	IGNR
GENRE		gnre	—
LANGUAGE	TLAN		language	ILNG
PODCASTDESC	TDES		—
PODCASTDESC		ldes	synopsis
DESCRIPTION		desc	description
COMMENT	COMM	©cmt	comment	ICMT
UNSYNCEDLYRICS	USLT	©lyr	lyrics
YEAR	TYER / TDRC		date(2.4)	ICRD
YEAR		©day	year
RELEASETIME	TDRL		date
ENCODINGTIME	— / TDEN		creation_time

PS: FFmpeg schreibt manche Boxen nur in bestimmten Modi (MP4 vs. MOV vs. 3GP) und verwendet beim Lesen zum Teil andere Variablennamen als beim Schreiben, v.a. mit Unterstrich für Sortierfelder, oder unterscheidet sie nur beim Schreiben und nicht beim Lesen (z.B. author vs. artist):

FFmpeg (lesen)	MP4-Box
account_id	apID
account_type	akID (integer)
album_artist	aART
album	©alb
artist	©ART, ©aut, ©art
category	catg
chapter	©chp
comment	©cmt, ©inf
compilation	cpil (integer)
composer	©com, ©wrt
copyright	cprt, ©cpy
date	©day
description	desc
director	©dir
disc	disk (integer[/integer])
disclaimer	©dis
edit_date	©ed1
encoder	©enc, ©swr, ©too
episode_id	tven
episode_sort	tves (integer)
episode_uid	egid (integer)
firmware	FIRM
gapless_playback	pgap (integer)
genre	gnre (integer|string), ©gen (string)
grouping	©grp
hd_video	hdvd (integer)
host_computer	©hst
keywords	keyw
location	©xyz, loci
lyrics	©lyr
make	manu, ©mak
media_type	stik (integer)
model	modl, ©mod
network	tvnn
original_artist	©ope
original_format	©fmt
original_source	©src
performers	©prf
playback_requirements	©req
podcast	pcst (integer)
producer	©prd, ©PRD
purchase_date	purd
rating	rtng (integer)
season_number	tvsn (integer)
show	tvsh
sort_album	soal
sort_album_artist	soaa
sort_artist	soar
sort_composer	soco
sort_name	sonm
sort_show	sosn
subtitle	©st3
synopsis	ldes
title	©nam titl
track	trkn (integer[/integer]), ©trk (integer)
URL	©url
warning	©wrn

[Crissov]

ExifTool

Die Doku für ExifTool ist äußerst umfassend.

ItemList

• PODCASTID (Episode Global Unique ID) wird in der Mp3tag-Doku klein egid, bei ExifTool aber groß egID geschrieben.
• Daneben kennt ExifTool weitere MP4-IDs:
  • atID (Album Title ID),
  • plID (Playlist ID),
  • prID (Product ID),
  • akID (Apple Store Account Type) und
  • sfID (Apple Store Country).
• Für CONTENTGROUP gibt es neben ©grp auch das Atom grup.
• Für TITLE gibt es neben ©nam (Name) auch das 3GP-Atom titl.
• Für ALBUM gibt es neben ©alb auch das 3GP-Atom albm.
• Für COPYRIGHT (TCOP) gibt es neben ©cpy auch das 3GP-Atom cprt.
• Für ARTIST gibt es neben ©art auch die Atoms ©aut (QT) und auth (3GP) für Author.
• Für COMPOSER gibt es neben ©wrt(Writer) auch das Atom ©com.
• Die Atoms perf (Performer, 3GP) und ©nrt (Narrator) scheinen Mp3tag unbekannt zu sein.
• Für PUBLISHER (ID3: TPUB) gibt es das Atom ©pub (Publisher), das Mp3tag nicht zu kennen scheint.
• Das boolesche Apple-Atom itnu identifiziert(e) offenbar akademischen Content von iTunes U.
• Für GENRE kennt ExifTool neben ©gen und gnre (3GP) auch geID (Genre ID).
• Für DESCRIPTION kennt ExifTool neben desc auch ©des (QT) und dscp (3GP) als Description.
• Für YEAR oder RELEASETIME kommen neben ©day auch yrrc (Year, 3GP) und rldt (Release Date) infrage.

PS: ©swr, ©mak, ©mod, ©xyz, ©key sind weitere spezifische Atoms für QT/MOV.
PPS: Ich glaube, ich habe immer noch keine richtige Ahnung von MP4-Atoms/Boxes.

[Crissov]

MP4RA-Tabellen

$20 denotes U+0020, the Space character.

Type: ISO family

Code	Description	Specification
ID32	ID3 version 2 container	id3v2
UITS	Unique Identifier Technology Solution	Universal Music Group
ainf	Asset information to identify, license and play	DECE
assp	alternative startup sequence properties	ISO
avcn	AVC NAL Unit Storage Box	DECE
bidx	Box Index	ISO-Partial
bloc	Base location and purchase location for license acquisition	DECE
bpcc	Bits per component	JPEG2000
buff	Buffering information	NALu Video
bxml	binary XML container	ISO
ccid	OMA DRM Content ID	OMA DRM 2.1
cdef	type and ordering of the components within the codestream	JPEG2000
cinf	complete track information	ISO
clip	reserved	ISO
cmap	mapping between a palette and codestream components	JPEG2000
co64	64-bit chunk offset	ISO
coin	Content Information Box	DECE
colr	specifies the colourspace of the image	JPEG2000
crgn	reserved	ISO
crhd	reserved for ClockReferenceStream header	MP4v1
csgp	compact sample to group	ISO
cslg	composition to decode timeline mapping	ISO
cstb	corrected wall clock start time	ONVIF
ctab	reserved	ISO
ctts	(composition) time to sample	ISO
cvru	OMA DRM Cover URI	OMA DRM 2.1
dihd	Data Integrity Hash	ISO-Partial
dinf	data information box, container	ISO
dint	Data Integrity	ISO-Partial
dref	data reference box, declares source(s) of media data in track	ISO
dsgd	DVB Sample Group Description Box	DVB
dstg	DVB Sample to Group Box	DVB
edts	edit list container	ISO
elst	an edit list	ISO
emsg	event message	DASH
etyp	extended type and type combination	ISO
evti	Event information	ATSC 3.0
fdel	File delivery information (item info extension)	ISO
feci	FEC Informatiom	ISO
fecr	FEC Reservoir	ISO
fidx	Box File Index	ISO-Partial
fiin	FD Item Information	ISO
fire	File Reservoir	ISO
fpar	File Partition	ISO
free	free space	ISO
frma	original format box	ISO
frpa	Front Part	ISO-Partial
ftyp	file type and compatibility	ISO
gitn	Group ID to name	ISO
grpi	OMA DRM Group ID	OMA DRM 2.0
grpl	Groups List box	HEIF
hdlr	handler, declares the media (handler) type	ISO
hmhd	hint media header, overall information (hint track only)	ISO
hpix	Hipix Rich Picture (user-data or meta-data)	Hipix
icnu	OMA DRM Icon URI	OMA DRM 2.0
idat	Item data	ISO
ihdr	Image Header	JPEG2000
iinf	item information	ISO
iloc	item location	ISO
imap	reserved	ISO
imda	Identified media data	ISO
imif	IPMP Information box	ISO
infe	Item information entry	ISO
infu	OMA DRM Info URL	OMA DRM 2.0
iods	Object Descriptor container box	MP4v1
ipco	ItemPropertyContainerBox	HEIF
iphd	reserved for IPMP Stream header	MP4v1
ipma	ItemPropertyAssociation	HEIF
ipmc	IPMP Control Box	ISO
ipro	item protection	ISO
iprp	Item Properties Box	HEIF
iref	Item reference	ISO
j2kH	JPEG 2000 header item property	J2KHEIF
jP$20$20	JPEG 2000 Signature	JPEG2000
jp2c	JPEG 2000 contiguous codestream	JPEG2000
jp2h	Header	JPEG2000
jp2i	intellectual property information	JPEG2000
kmat	reserved	ISO
leva	Leval assignment	ISO
load	reserved	ISO
loop	Looping behavior	WhatsApp
lrcu	OMA DRM Lyrics URI	OMA DRM 2.1
m7hd	reserved for MPEG7Stream header	MP4v1
matt	reserved	ISO
md5i	MD5IntegrityBox	HEIF
mdat	media data container	ISO
mdhd	media header, overall information about the media	ISO
mdia	container for the media information in a track	ISO
mdri	Mutable DRM information	OMA DRM 2.0
meco	additional metadata container	ISO
mehd	movie extends header box	ISO
mere	metabox relation	ISO
meta	Metadata container	ISO
mfhd	movie fragment header	ISO
mfra	Movie fragment random access	ISO
mfro	Movie fragment random access offset	ISO
minf	media information container	ISO
mjhd	reserved for MPEG-J Stream header	MP4v1
moof	movie fragment	ISO
moov	container for all the meta-data	ISO
mstv	MVC Sub-track view box	NALu Video
mvcg	Multiview group	NALu Video
mvci	Multiview Information	NALu Video
mvdr	MVDDepthResolutionBox	NALu Video
mvex	movie extends box	ISO
mvhd	movie header, overall declarations	ISO
mvra	Multiview Relation Attribute	NALu Video
nmhd	Null media header, overall information (some tracks only)	ISO
ochd	reserved for ObjectContentInfoStream header	MP4v1
odaf	OMA DRM Access Unit Format	OMA DRM 2.0
odda	OMA DRM Content Object	OMA DRM 2.0
odhd	reserved for ObjectDescriptorStream header	MP4v1
odhe	OMA DRM Discrete Media Headers	OMA DRM 2.0
odrb	OMA DRM Rights Object	OMA DRM 2.0
odrm	OMA DRM Container	OMA DRM 2.0
odtt	OMA DRM Transaction Tracking	OMA DRM 2.0
ohdr	OMA DRM Common headers	OMA DRM 2.0
padb	sample padding bits	ISO
paen	Partition Entry	ISO
pclr	palette which maps a single component in index space to a multiple-component image	JPEG2000
pdat	Partial Data	ISO-Partial
pdin	Progressive download information	ISO
pfhd	Partial File Header	ISO-Partial
pfil	Partial File	ISO-Partial
pitm	primary item reference	ISO
ploc	Partial Segment Location	ISO-Partial
pnot	reserved	ISO
prft	Producer reference time	ISO
pseg	Partial Segment	ISO-Partial
pshd	Partial Segment Header	ISO-Partial
pssh	Protection system specific header	ISO Common Encryption
ptle	Partial Top Level Entry	ISO-Partial
res$20	grid resolution	JPEG2000
resc	grid resolution at which the image was captured	JPEG2000
resd	default grid resolution at which the image should be displayed	JPEG2000
rinf	restricted scheme information box	ISO
saio	Sample auxiliary information offsets	ISO
saiz	Sample auxiliary information sizes	ISO
sbgp	Sample to Group box	ISO
schi	scheme information box	ISO
schm	scheme type box	ISO
sdep	Sample dependency	NALu Video
sdhd	reserved for SceneDescriptionStream header	MP4v1
sdtp	Independent and Disposable Samples Box	ISO
sdvp	SD Profile Box	SDV
segr	file delivery session group	ISO
seii	SEI information box	NALu Video
senc	Sample specific encryption data	ISO Common Encryption
sgpd	Sample group definition box	ISO
sidx	Segment Index Box	3GPP
sinf	protection scheme information box	ISO
skip	free space	ISO
smhd	sound media header, overall information (sound track only)	ISO
srmb	System Renewability Message	DVB
srmc	System Renewability Message container	DVB
srpp	STRP Process	ISO
ssix	Sub-sample index	ISO
sstl	SVC Sub-track layer box	NALu Video
stbl	sample table box, container for the time/space map	ISO
stco	chunk offset, partial data-offset information	ISO
stdp	sample degradation priority	ISO
sthd	Subtitle Media Header Box	ISO
stmg	MVC Sub-track multiview group box	NALu Video
strd	Sub-track definition	ISO
stri	Sub-track information	ISO
stsc	sample-to-chunk, partial data-offset information	ISO
stsd	sample descriptions (codec types, initialization etc.)	ISO
stsg	Sub-track sample grouping	ISO
stsh	shadow sync sample table	ISO
stss	sync sample table (random access points)	ISO
stsz	sample sizes (framing)	ISO
stti	Sub-track tier box	NALu Video
stts	(decoding) time-to-sample	ISO
styp	Segment Type Box	3GPP
stz2	compact sample sizes (framing)	ISO
subs	Sub-sample information	ISO
suep	signer identity information	ONVIF
sumi	supplemental surveillance meta information	MPEG-VSAF
surl	Source URL	ISO-Partial
swtc	Multiview Group Relation	NALu Video
tenc	Track Encryption	ISO Common Encryption
tfad	Track fragment adjustment box	3GPP
tfdt	Track fragment decode time	ISO
tfhd	Track fragment header	ISO
tfma	Track fragment media adjustment box	3GPP
tfra	Track fragment radom access	ISO
tibr	Tier Bit rate	NALu Video
tiri	Tier Information	NALu Video
tkhd	Track header, overall information about the track	ISO
traf	Track fragment	ISO
trak	container for an individual track or stream	ISO
tref	track reference container	ISO
trep	track extension properties	ISO
trex	track extends defaults	ISO
trgr	Track grouping information	ISO
trik	Facilitates random access and trick play modes	DECE
trun	track fragment run	ISO
tstb	TileSubTrackGroupBox	NALu Video
ttyp	track type and compatibility	ISO
tyco	type and-combination	ISO
udta	user data	ISO
uinf	a tool by which a vendor may provide access to additional information associated with a UUID	JPEG2000
ulst	a list of UUID’s	JPEG2000
url$20	a URL	JPEG2000
uuid	user-extension box	ISO
vmhd	video media header, overall information (video track only)	ISO
vwdi	Multiview Scene Information	NALu Video
xml$20	XML container	ISO
xml$20	a tool by which vendors can add XML formatted information	JPEG2000

hpix also in User-Data.

Type: User-Data

Code	Description	Specification
ades	description of the content for accessibility purposes (similar to the HTML alt attribute); formatted as for the cprt user-data item	Apple
albm	Album title and track number for media	3GPP
alou	Album loudness base	ISO
angl	Name of the camera angle through which the clip was shot	Apple
auth	Author of the media	3GPP
clfn	Name of the clip file	Apple
clid	Identifier of the clip	Apple
clsf	Classification of the media	3GPP
cmid	Identifier of the camera	Apple
cmnm	Name that identifies the camera	Apple
coll	Name of the collection from which the media comes	3GPP
cprt	copyright etc.	ISO
date	Date and time, formatted according to ISO 8601, when the content was created. For clips captured by recording devices, this is typically the date and time when the clip’s recording started.	Apple
dscp	Media description	3GPP
gnre	Media genre	3GPP
hinf	hint information	ISO
hnti	Hint information	ISO
hpix	Hipix Rich Picture (user-data or meta-data)	Hipix
kind	Track kind	ISO
kywd	Media keywords	3GPP
loci	Media location information	3GPP
ludt	Track loudness container	ISO
manu	Manufacturer name of the camera	Apple
modl	Model name of the camera	Apple
orie	Orientation information	3GPP
perf	Media performer name	3GPP
reel	Name of the tape reel	Apple
rtng	Media rating	3GPP
scen	Name of the scene for which the clip was shot	Apple
shot	Name that identifies the shot	Apple
slno	Serial number of the camera	Apple
strk	Sub-track information	ISO
thmb	Thumbnail image of the media	3GPP
titl	Media title	3GPP
tlou	Track loudness base	ISO
tsel	Track selection	ISO
urat	User 'star' rating of the media	3GPP
yrrc	Year when media was recorded	3GPP

8.2 3GPP asset meta data

A user-data box (udta) … may be present in conforming files. …

• titl – title for the media (…)
• dscp – caption or description for the media (…)
• cprt – notice about organisation holding copyright for the media file (…)
• perf – performer or artist (…)
• auth – author of the media (…)
• gnre – genre (category and style) of the media (…)
• rtng – media rating (…, with 4-char Entity and Criteria fields, e.g. BBFC and PG13)
• clsf – classification of the media (…, with 4-byte Entity and 2-byte Table Index)
• kywd – media keywords (…, with integer Count and Array)
• loci – location information (…, coordinates Long/Lat/Alt/Body etc.)
• albm – album title and track number for the media (…, includes track number)
• yrrc – recording year for the media (…, integer value)
• coll – name of the collection from which the media comes (…)
• urat – user 'star' rating of the media (…, 10 through 50, or 0)
• thmb — thumbnail image of the media (…, only JPEG)
• orie – orientation information (…, camera Zoom/Pan/Rot/Tilt)

ID3 version 2 meta data

(id32 inside meta)

Type: QuickTime

Code	Description	Specification
albm	Album title and track number for media	3GPP
auth	Author of the media	3GPP
clsf	Classification of the media	3GPP
clip	Visual clipping region container	QT
cprt	copyright etc.	ISO
crgn	Visual clipping region definition	QT
crgn	Visual clipping region definition	QT
ctab	Track color-table	QT
dcfD	Marlin DCF Duration	OMArlin
elng	Extended Language Tag	QT
imap	Track input map definition	QT
kmat	Compressed visual track matte	QT
load	Track pre-load definitions	QT
matt	Visual track matte for compositing	QT
pnot	Preview container	QT
wide	Expansion space reservation	QT

albm, auth, clsf, cprt are also in the User-Data section.

Edit 2021-03-08: OMA DRM URLs updated.
Edit 2021-04-03: Split tables by Type.
Edit 2021-04-08: 3GPP quote

[Crissov]

Original Apple Quicktime (MOV) Atoms

QTFF udta

Type	Description	Sorting
©arg	Name of arranger
©ark	Keywords for arranger	yes
©cok	Keywords for composer	yes
©com	Name of composer
©cpy	Copyright statement
©day	Date the movie content was created
©dir	Name of movie’s director
©ed1 … ©ed9	Edit dates and descriptions
©fmt	Indication of movie format (computer-generated, digitized, and so on)
©inf	Information about the movie
©isr	ISRC code
©lab	Name of record label
©lal	URL of record label
©mak	Name of file creator or maker
©mal	URL of file creator or maker
©nak	Title keywords of the content	yes
©nam	Title of the content
©pdk	Keywords for producer	yes
©phg	Recording copyright statement, normally preceded by the symbol ℗
©prd	Name of producer
©prf	Names of performers
©prk	Keywords of main artist and performer	yes
©prl	URL of main artist and performer
©req	Special hardware and software requirements
©snk	Subtitle keywords of the content	yes
©snm	Subtitle of content
©src	Credits for those who provided movie source content
©swf	Name of songwriter
©swk	Keywords for songwriter	yes
©swr	Name and version number of the software (or hardware) that generated this movie
©wrt	Name of movie’s writer
AllF	Play all frames—byte indicating that all frames of video should be played, regardless of timing
hinf	Hint Track User Data Atom—statistical data for real-time streaming of a particular track.
hnti	Movie Hint Info Atom—data used for real-time streaming of a movie or a track.
name	Name of object
tnam	Localized Track Name optionally present in Track user data.
tagc	Media Characteristic Tags optionally present in Track user data—specialized text that describes something of interest about the track.
LOOP	Long integer indicating looping style. This atom is not present unless the movie is set to loop. Values are 0 for normal looping, 1 for palindromic looping.
ptv	Print to Video—display movie in full screen mode. This atom contains a 16-byte structure.
SelO	Play selection only—byte indicating that only the selected area of the movie should be played
WLOC	Default window location for movie—two 16-bit values, {x,y}

[Crissov]

Leo van Stee: “On date, time, location and other metadata in MP4/MOV files”

[phw]

Tolle Auflistung. Apple hatte auch das Dokument "iTunes Metadata Format Specification" publiziert. Die erste version 2005, die letzte Aktualisierung die ich kenne war von 2008. Das Dokument stellt Apple schon seit einigen Jahren nicht mehr zur Verfügung. Aber es war maßgebend für viele der Tags, die Musikplayer und -tagger unterstützen, da die meisten versucht haben zu iTunes kompatibel zu sein. Hier sind die relevanten Tags aus der Spezifikation:

Defined tags recognized by iTunes

Element	Additional Description	Tag	Data Type
Album Name		©alb	UTF string
Artist		©ART	UTF string
User Comment		©cmt	UTF string
Cover Art	One or more cover art images	covr	JPEG/PNG/BMP data
Copyright		cprt	UTF string
Release Date	YYYY-MM-DD format string (may beincomplete, i.e. only year)	©day	UTF string
Encoded By	Person or company that encoded the recording	©enc	UTF string
Pre-defined Genre	Enumerated value from ID3 tag set, plus 1 (set identifier = 0)	gnre	enum
User Genre	User-specified string	©gen	UTF string
Song Name		©nam	UTF string
Track Sub-Title		©st3	UTF string
Encoding Tool	Software which encoded the recording	©too	UTF string
Composer		©wrt	UTF string
Album Artist	Artist for the whole album (if different than the individual tracks)	aART	UTF string
Disc Compilation	Is disc part of a compilation?	cpil	8-bit "boolean" integer
Disc Number	The data-type 0 is used, implicitly identifying the disk-number record used above	disk	Binary data
Grouping	Overall work (like TIT1 in ID3)	grup	UTF string
Content Rating	Does song have explicit content?	rtng	8-bit "boolean" integer
Beats Per Minute		tmpo	32-bit integer
Track Number	The data-type 0 is used, implicitly identifying the track-number record used above	trkn	Binary data

The following tags may also be used; not all software recognizes or interprets them:

Element	Additional Description	Tag	Data Type
Art Director	Person(s) responsible for non-photographic artwork used with content	©ard	UTF string
Arranger	Person(s) responsible for the particular adaptation of composition	©arg	UTF string
Lyricist/Author	Name Writer of the song lyrics	©aut	UTF string
Copyright Acknowledgement(s)	Ackowledgements of those granting permission to use copyrighted material	©cak	UTF string
Conductor	Name of the person who directed the orchestra	©con	UTF string
Song Description	Explanation of the son g	©des	UTF string
Director	Name of director for Movie/Video	©dir	UTF string
Equalization preset name	Setting for Equalization of content	©equ	UTF string
Liner Notes	Explanatory notes about a record album, cassette, or compact disk included on the jacket or in the packaging.	©lnt	UTF string
Record Company	Company releasing the song	©mak	UTF string, URL
Original Artist	Name of artist originally attributed with content	©ope	UTF string
Phonogram Rights (P-Line)	Like a copyright, but using the circled P symbol, for audio rights	©phg	UTF string
Producer	Person(s) responsible for creating/supervising the song	©prd	UTF string
Performer	Name/URL of the individual primary members of the band/group	©prf	UTF string, URL
Publisher	Company publishing the song	©pub	UTF string
Sound Engineer	The name of the person doing sound engineering	©sne	UTF string
Soloist	Name of the musician who performs the solo	©sol	UTF string
Credits	Credits for those who provided source content	©src	UTF string
Thanks/Dedications	Notes of acknowledgement/recognition from Artist	©thx	UTF string
Online Extras	Links to content that can only be accessed when connected to the Internet	©url	URL
Executive Producer	Person(s) responsible for creating/supervising the song	©xpd	UTF string

Das beantwortet auch einige der Besonderheiten, die Du oben erwänst:

@Crissov

Für GENRE kennt ExifTool neben ©gen und gnre (3GP) auch geID (Genre ID).

©gen: Freitext, gnre: Genre-ID aus der ID3-Spezifikation.

@Crissov

Für CONTENTGROUP gibt es neben ©grp auch das Atom grup.

grup für grouping erwähnt das Dokument auch. Aber aktuelles iTunes / Apple Music verwendet tatsächlich ©grp. Vielleicht wurde das später geändert oder war schon immer so. Ich weiß nicht ob grup gelesen werden würde.

@Crissov

Für ARTIST gibt es neben ©art auch die Atoms ©aut (QT) und auth (3GP) für Author.

©art ist normalerweise der Künstler, der auch die Credits bekommt. ©aut ist ganz klar der Autor (Text und/oder Musik).

[Crissov]

Ich habe gestern mal öffentlich über Github bei der MP4RA nachgefragt:

How to register common, but undocumented boxes?

[phw]

Die Seite hat scheinbar was Metadaten für Musik-Dateien angeht recht wenig relevant. Keines der in der Praxis relevanten Atome ist dort gelistet (©alb, ©ART, aART, covr, ©gen, ©nam, ...). Ausnahme ist cprt.

Und selbst von denen, die dort aufgeführt sind, wären nur wenige für Musik wirklich relevant. Ein paar wenige wie albm, coll, gnre, cprt und evtl. noch ein paar mehr. Aber in der Praxis unterstützt wird dann eher was Apple mit iTunes und ihrem Store liefert.

[Crissov]

Unabhängig davon, ob iTunes/Music die Daten tatsächlich verwendet, würde ich @Florian für Mp3tag vorschlagen, die folgenden MP4-Boxen für existierende ID3-Variablen hinzuzufügen, zumindest die fett hervorgehobenen:

Name in Mp3tag	ID3v2	MP4
ENCODERSETTINGS	TSSE	©too (©swr?)
GROUPING	GRP1	(catg? Category)
SETSUBTITLE	TSST	(©snm? Content Subtitle)
SUBTITLE	TIT3	©st3 Subtitle
INVOLVEDPEOPLE	IPLS / TIPL	©src Credits (©thx?, ©cak?)
MUSICIANCREDITS	TMCL	©src Credits (©thx?, ©cak?)
PUBLISHER	TPUB	©pub Publisher, ©mak? Record Company, (©lab? Record Label)
LYRICIST	TEXT	©aut Lyricist/Author
ORIGLYRICIST	TOLY	©aut? Lyricist/Author, (©swk? Songwriter)
ENCODEDBY	TENC	©enc Encoded by, ©sne? Sound Engineer
MIXARTIST	TPE4	©arg Arranger
ORIGARTIST	TOPE	©ope Original Artist
ORIGYEAR	TORY / TDOR	(©ed0?)
ENCODINGTIME	TDEN	(©ed1?)
TAGGINGTIME	TDTG	(©ed2?)
RELEASETIME	TDRL	(rldt?, yrrc?)
ISRC	TSRC	©isr
MEDIATYPE	TMED	(©fmt?)
LANGUAGE	TLAN	(elng?)
WWW	WXXX	©url
WWWARTIST	WOAR	©prf?, (©prl?)
WWWAUDIOFILE	WOAF	(©mal?)
WWWPUBLISHER	WPUB	(©lal?)
ORIGFILENAME	TOFN	(clfn?)
POPULARIMETER	POPM	(urat?)
RATING MM / RATING WMP	POPM	(urat?)

Für die folgenden Felder sehe ich keine Entsprechungen:

Name in Mp3tag	ID3v2
FILEOWNER	TOWN
FILETYPE	TFLT
INITIALKEY	TKEY
LENGTH	TLEN
MOOD	TMOO
NETRADIOOWNER	TRSO
NETRADIOSTATION	TRSN
ORIGALBUM	TOAL
WWWAUDIOSOURCE	WOAS
WWWCOMMERCIALINFO	WCOM
WWWCOPYRIGHT	WCOP
WWWPAYMENT	WPAY
WWWRADIOPAGE	WORS

[phw]

@Crissov

|GROUPING|GRP1|(catg? Category)

Das sollte ©grp sein, da so auch von Playern unterstützt.

[Crissov]

Das kennt Mp3tag schon, aber mit anderem Mapping und entsprechend anderer Bedeutung:

Mp3tag	ID3v2	MP4
CONTENTGROUP	TIT1	©grp

Das ID3v2-Frame GRP1 aus der Mp3tag-Doku ist nicht Teil des Standards, sondern wurde von Apple erfunden:

Support for new iTunes Grouping id3 frame "GRP1"?

With this week's iTunes' release of 12.5.4.42, iTunes is now writing "Grouping" values from its library out to a new ID3 frame "GRP1". Support of this new "iTunes Grouping" frame in Mp3tag would be a very useful alternative to the problematic "Work" / TIT1 frame to store mood & style keywords.

[Florian]

Ich sehe darin das Problem der Kompatibilität mit anderere Software. Falls ich z.B. SUBTITLE als ©st3 schreiben würde, könnten andere Programme wie z.B. MusicBrainz Picard oder foobar2000 nicht mehr darauf zugreifen.

Ich gehe davon aus, dass die Unterstützung dann nach und nach umgesetzt werden würde, aber erstmal würde es eine Zeit der Inkompatibilität geben, unter der dann meistens die Benutzer zu leiden haben.

Sind Dir denn Programme bekannt, die die fett hervorgehobenen MP4-Felder unterstützen? Ich frage das aus Interesse und nicht als Teil einer Argumentation.

[Crissov]

Nein, ich habe noch nicht untersucht, welche Tag-, Verwaltungs- oder Abspielprogramme diese Boxen lesend unterstützen oder sogar selbst schreiben.
Es wäre sinnvoll, eine entsprechende Testdatei zu präparieren und in verschiedenen Programmen zu testen.

Musicbrainz Picard und Foobar2000 verwenden die private Box ---- mit dem iTunes-Namensraum: ----:com.apple.iTunes:TAGFELD.

[Crissov]

Here's a comparison of ----:com.apple.iTunes: boxes supported by Musicbrainz Picard and Foobar2000 with the more obscure MP4 boxes I suggested be added to Mp3tag above.

Mp3tag	ID3v2.4 tag field (v2.3)	MP4 box	MP4 private box	Foobar2000	Picard title	Picard variable
POPULARIMETER / RATING MM / RATING WMP	POPM	(urat)
ORIGYEAR	TORY (TDOR)	(©ed0)
ENCODINGTIME	TDEN	(©ed1)
TAGGINGTIME	TDTG	(©ed2)
RELEASETIME	TDRL	(rldt, yrrc)
ENCODEDBY	TENC	©enc, ©sne
PUBLISHER	TPUB	©pub, ©mak, (©lab)	LABEL	Label	Record Label	label
MUSICIANCREDITS	TMCL	©src (©thx, ©cak)
INVOLVEDPEOPLE	TIPL (IPLS)	©src (©thx, ©cak)
	TIPL:engineer (IPLS:engineer)		ENGINEER	Engineer	Engineer	engineer
	TIPL:mix (IPLS:mix)		MIXER	Mix Engineer	Mixer	mixer
	TIPL:producer (IPLS:producer)		PRODUCER	Producer	Producer	producer
	TIPL:DJ-mix (IPLS:DJ-mix)		DJMIXER	Mix-DJ	Mix-DJ	djmixer
CONDUCTOR	TPE3	©con	CONDUCTOR	Conductor	Conductor	conductor
MIXARTIST	TPE4	©arg	REMIXER	Remixed By / Mix Artist	Remixer	remixer
LYRICIST	TEXT	©aut	LYRICIST	Lyricist	Lyricist	lyricist
ORIGLYRICIST	TOLY	©aut, (©swk)
ORIGARTIST	TOPE	©ope
SUBTITLE	TIT3	©st3	SUBTITLE	Track Subtitle	Subtitle	subtitle
SETSUBTITLE	TSST	(©snm)	DISCSUBTITLE	Disc / Set Subtitle (for multi-disc sets)	Disc Subtitle	discsubtitle
GROUPING	GRP1	(catg)
LANGUAGE	TLAN	(elng)	LANGUAGE	Language	Language	language
MEDIATYPE	TMED	(©fmt)	MEDIA	Media Type / Release Format	Media	media
MOOD	TMOO		MOOD	Mood	Mood	mood
ISRC	TSRC	©isr	ISRC	ISRC	ISRC	isrc
ENCODERSETTINGS	TSSE	©too (©swr)
	TXXX:BARCODE		BARCODE	Barcode	Barcode	barcode
	TXXX:CATALOGNUMBER		CATALOGNUMBER	Catalogue Number	Catalog Number	catalognumber
	TXXX:SCRIPT		SCRIPT	Script	Script	script
WWWCOPYRIGHT (multiple or non-URL)	TXXX:LICENSE		LICENSE	License	License	license
WWWCOPYRIGHT (single URL)	WCOP		LICENSE	License	License	license
WWWAUDIOFILE	WOAF	(©mal)
WWWARTIST	WOAR	©prf, (©prl)
WWWPUBLISHER	WPUB	(©lal)
WWW	WXXX	©url
ORIGFILENAME	TOFN	(clfn)
INITIALKEY	TKEY		initialkey		Initial Key	key

MusicBrainz etc.

ID3v2 tag field	MP4 private box	Picard title	Picard variable
TXXX:ARTISTS	ARTISTS	Artists	artists
TXXX:ASIN	ASIN	ASIN	asin
TXXX:Acoustid Id	Acoustid Id	AcoustID	acoustid_id
TXXX:Acoustid Fingerprint	Acoustid Fingerprint	AcoustID Fingerprint	acoustid_fingerprint
TXXX:MusicMagic Fingerprint	fingerprint	MusicIP Fingerprint	musicip_fingerprint
TXXX:MusicIP PUID	MusicIP PUID	MusicIP PUID	musicip_puid
TXXX:MusicBrainz Album Release Country	MusicBrainz Album Release Country	Release Country	releasecountry
TXXX:MusicBrainz Album Status	MusicBrainz Album Status	Release Status	releasestatus
TXXX:MusicBrainz Album Type	MusicBrainz Album Type	Release Type	releasetype
TXXX:MusicBrainz Album Artist Id	MusicBrainz Album Artist Id	MusicBrainz Release Artist ID	musicbrainz_albumartistid
TXXX:MusicBrainz Album Id	MusicBrainz Album Id	MusicBrainz Release ID	musicbrainz_albumid
TXXX:MusicBrainz Artist Id	MusicBrainz Artist Id	MusicBrainz Artist ID	musicbrainz_artistid
TXXX:MusicBrainz Disc Id	MusicBrainz Disc Id	MusicBrainz Disc ID	musicbrainz_discid
TXXX:MusicBrainz Original Album Id	MusicBrainz Original Album Id	MusicBrainz Original Release ID	musicbrainz_originalalbumid
TXXX:MusicBrainz Original Artist Id	MusicBrainz Original Artist Id	MusicBrainz Original Artist ID	musicbrainz_originalartistid
TXXX:MusicBrainz Release Group Id	MusicBrainz Release Group Id	MusicBrainz Release Group ID	musicbrainz_releasegroupid
TXXX:MusicBrainz Release Track Id	MusicBrainz Release Track Id	MusicBrainz Track ID	musicbrainz_trackid
TXXX:MusicBrainz TRM Id	MusicBrainz TRM Id	MusicBrainz TRM ID	musicbrainz_trmid (deprecated)
TXXX:MusicBrainz Work Id	MusicBrainz Work Id	MusicBrainz Work ID	musicbrainz_workid
UFID:http://musicbrainz.org	MusicBrainz Track Id	MusicBrainz Recording ID	musicbrainz_recordingid
TXXX:REPLAYGAIN_ALBUM_GAIN	REPLAYGAIN_ALBUM_GAIN	ReplayGain Album Gain	replaygain_album_gain
TXXX:REPLAYGAIN_ALBUM_PEAK	REPLAYGAIN_ALBUM_PEAK	ReplayGain Album Peak	replaygain_album_peak
TXXX:REPLAYGAIN_ALBUM_RANGE	REPLAYGAIN_ALBUM_RANGE	ReplayGain Album Range	replaygain_album_range
TXXX:REPLAYGAIN_REFERENCE_LOUDNESS	REPLAYGAIN_REFERENCE_LOUDNESS	ReplayGain Reference Loudness	replaygain_reference_loudness
TXXX:REPLAYGAIN_TRACK_GAIN	REPLAYGAIN_TRACK_GAIN	ReplayGain Track Gain	replaygain_track_gain
TXXX:REPLAYGAIN_TRACK_PEAK	REPLAYGAIN_TRACK_PEAK	ReplayGain Track Peak	replaygain_track_peak
TXXX:REPLAYGAIN_TRACK_RANGE	REPLAYGAIN_TRACK_RANGE	ReplayGain Track Range	replaygain_track_range

[Crissov]

VLC

Dem VLC-Quellcode zufolge liest das Programm praktisch alle jemals von Apple dokumentierten MP4-Metadaten-Felder.

Formatübergreifende Metadatenfelder

Atom	VLC-Variable	Kommentar
©nam	Title	Full name
©alb	Album	Album
©aut	Artist
©ART	Artist
aART	AlbumArtist
©pub	Publisher
©dir	Director
©cpy	Copyright
©cmt	Description	Comment
©des	Description	Description
desc	Description
©day	Date	Creation Date
©gen	Genre	Genre
©trk	TrackNumber	Track
©url	URL	URL
©too	EncodedBy	Encoder Tool
©enc	EncodedBy	Encoded By
@PRM	EncodedBy	Adobe Premiere
@PRQ	EncodedBy	Adobe Qt
MCPS	EncodedBy	Cleaner Pro

MP4-spezifische Metadatenfelder

Atom	VLC-Variable	Kommentar
©wrt	Writer
©com	Composer
©prd	Producer
©arg	Arranger
©ard	Art Director
©con	Conductor
©prf	Performers
©ope	Original Performer
©sne	Sound Engineer
©sol	Soloist
©xpd	Executive Producer
©inf	Information
©dis	Disclaimer
©req	Requirements
©fmt	Original Format
©dsa	Display Source As
©hst	Host Computer
©src	Providers Source Content
©wrn	Warning
©swr	Software
©lyr	Lyrics
©phg	Phonogram Rights
©pub	Publisher
©mak	Record Company
©mod	Model
©PRD	Product
©gen	Genre
©grp	Grouping
©st3	Sub-Title
©des	Song Description
©lnt	Liner Notes
©cak	Copyright Acknowledgement
©thx	Thanks
aART	Album Artist
flvr	Encoding Params
purl	Podcast URL
vndr	Vendor
xid_	Catalog Number

Google/YouTube

Atom	VLC-Variable	Kommentar
gshh	YouTube Host
gspm	YouTube Ping Message
gspu	YouTube Ping Url
gssd	YouTube Source Data
gsst	YouTube Start Time
gstd	YouTube Track Duration

[Crissov]

GPAC / MP4Box

MP4Box supported iTunes tags

Die direkte Unterstützung von iTunes-Tags wurde in MP4Box erst vor kurzem aktualisiert. Sie entspricht jetzt ungefähr dem Stand von Mp3tag, Foobar2000 und Picard. Außerdem können auch beliebige udta-Boxen hinzugefügt und gelesen werden:

• mp4box -tag-list
• mp4box -itags tag_name=tag_value [ :tag_name=tag_value ]*
• mp4box -itags filename

Ich habe für die folgende Tabelle Informationen aus den Quellcodedateien isomedia.h und constants.c zusammengeführt.

MP4-Feld	MP4Box-Variable	GF_ISOM_ITUNE_	ID3v2
©nam	title, name	NAME	TIT2
©ART	artist	ARTIST	TPE1
aART	album_artist, albumArtist	ALBUM_ARTIST	TPE2
©alb	album	ALBUM	TALB
©grp	group, grouping	GROUP	TIT1
©com	composer	COMPOSER	TCOM
©wrt	writer	WRITER	TEXT
©con	conductor	CONDUCTOR	TPE3
©cmt	comment, comments	COMMENT	COMM
©gnr	genre	GENRE_USER	TCON	dynamic
gnre	genre	GENRE	TCON	dynamic
©day	created, releaseDate	CREATED	TYER
©trk	track	TRACK
trkn	tracknum	TRACKNUMBER	TRCK
disk	disk	DISK	TPOS
tmpo	tempo	TEMPO	TBPM
cpil	complilation	COMPILATION	TCMP	typo
tvsh	show, tvShow	TV_SHOW
tven	episode_id, tvEpisodeID	TV_EPISODE
tvsn	season, tvSeason	TV_SEASON
tves	episode, tvEPisode	TV_EPISODE_NUM
tvnn	network, tvNetwork	TV_NETWORK
desc	sdesc, description	DESCRIPTION
ldes	ldesc, longDescription	LONG_DESCRIPTION	TDES
©lyr	lyrics	LYRICS	USLT
sonm	sort_name, sortName	SORT_NAME	TSOT
soar	sort_artist, sortArtist	SORT_ARTIST	TSOP
soaa	sort_album_artist, sortAlbumArtist	SORT_ALB_ARTIST	TSO2
soal	sort_album, sortAlbum	SORT_ALBUM	TSOA
soco	sort_composer, sortComposer	SORT_COMPOSER	TSOC
sosn	sort_show, sortShow	SORT_SHOW
covr	cover, artwork	COVER_ART
cprt	copyright	COPYRIGHT	TCOP
©too	tool, encodingTool	TOOL
©enc	encoder, encodedBy	ENCODER	TENC
purd	pdate, purchaseDate	PURCHASE_DATE
pcst	podcast	PODCAST
purl	url, podcastURL	PODCAST_URL
kyyw	keywords	KEYWORDS	TKWD
catg	category	CATEGORY	TCAT
hdvd	hdvideo	HD_VIDEO
stik	media, mediaType	MEDIA_TYPE
rtng	rating, contentRating	RATING
pgap	gapless	GAPLESS
----		ITUNES_DATA	(TXXX)

Einige Boxen werden in einem Kommentar erwähnt, da sie nicht implementiert bzw. schreibgeschützt sind:apID, akID, cnID, sfID, atID, plID, geID und ©st3.

[Florian]

Mit Mp3tag v3.06b habe ich Unterstützung für folgende iTunes-spezifischen Felder eingebaut:

• ITUNESALBUMID (plID),
• ITUNESARTISTID (atID),
• ITUNESCOMPOSERID (cmID),
• ITUNESCOUNTRYID (sfID),
• ITUNESGENREID (geID),
• und XID (xid )

[Crissov]

MediaMonkey 5 speichert einige Werte in nicht standardisierten Boxen innerhalb von User Data udta. Für MOV werden einige zusätzliche Boxen unterstützt sowie QT-Metadata-Atoms in mdta:com.apple.quicktime.. Für beide werden private Felder von iTunes :com.apple.iTunes: und WMP :Xtra:WM/ in ---- unterstützt. Felder in eckigen Klammern werden nur gelesen und nicht geschrieben, darunter 3GPP.

Property	ID3v2	MP4	+ MOV	iTunes ----	WMP ----	MOV mdta
Title	TIT2	©nam, [titl]				title
Artist(s) / Director(s)	TPE1	©ART, [auth]	©dir			director
Album / Podcast	TALB	©alb				album
Album Artist(s)	TPE2	aART
Date (Year)	TDRC, TYER, TDAT	©day				year
Genre(s)	TCON	©gen, gnre				genre
Disc #	TPOS	disk		DISCNUMBER	PartOfSet
Track #	TRCK	trkn		TRACKNUMBER
Rating	POPM	rate			SharedUserRating	rating.user
Comment	COMM	©cmt / ldes, [desc, ©des]	[©inf]			comment, [description]
Artwork	APIC	covr
Grouping	TIT1	©grp			ContentGroupDescription	collection.user
Composer(s)	TCOM	©wrt	[©com]
Conductor(s)	TPE3			CONDUCTOR	Conductor
Lyricist(s) / Written by	TEXT	[lyrc]		LYRICIST	Writer
Involved People	IPLS	[peop]		INVOLVED PEOPLE
Original Title	TOAL	[otit]		ORIGINAL ALBUM
Original Artist	TOPE	[oart]		ORIGINAL ARTIST
Original Lyricist	TOLY	[olyr]		ORIGINAL LYRICIST
Original Date (Year)	TDOR, TORY	[oday]		ORIGINAL DATE
Beats Per Minute	TBPM	tmpo
ISRC	TSRC	[isrc]	[©isr]	ISRC
Publisher	TPUB	[publ]		ORGANIZATION	Publisher
Encoder	TSSE	©too
Copyright	TCOP	cprt	[©cpy]			copyright
Classification: Tempo	COMM:Songs-DB_Tempo, COMM:MusicMatch_Tempo	[empo]		TEMPO
Classification: Mood(s)	TMOO, non-standard COMM:MusicMatch_Mood	[mood]		MOOD	Mood
Classification: Occasion(s)	COMM:Songs-DB_Occasion, COMM:MusicMatch_Situation	[occa]		OCCASION
Classification: Quality	COMM:Songs-DB_Preference, COMM:MusicMatch_Preference	[qual]		QUALITY
Lyrics	USLT	©lyr
Custom Field X	COMM:Songs-DB_CustomX			CUSTOMX
Volume Leveling Coefficient	TXXX:replaygain_track_gain, TXXX:replaygain_track_peak, TXXX:replaygain_album_gain, RGAD, [RVA2]			replaygain_track_gain, replaygain_track_peak, replaygain_album_gain
Initial Key	TKEY			initialkey
Extended tag NAME	TXXX:NAME			NAME
Parental rating				PARENTAL RATING
TV Episode number		tves / tven
TV Season number		tvsn
TV Show name = Series		tvsh
Producer			[©prd]	PRODUCER
Actor(s)			©prf	ACTORS