Run make doc, try to reconcile Dolby lack of spec, its code, and Medi…

…aInfo
wader · Oct 29, 2024 · c009996 · c009996
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diff --git a/README.md b/README.md
@@ -35,7 +35,6 @@ It was originally designed to query, inspect and debug media codecs and containe
 [aac_frame](doc/formats.md#aac_frame),
 adts,
 adts_frame,
-[adm](doc/formats.md#adm),
 aiff,
 amf0,
 apev2,
@@ -54,7 +53,6 @@ avc_sei,
 avc_sps,
 [avi](doc/formats.md#avi),
 [avro_ocf](doc/formats.md#avro_ocf),
-[axml](doc/formats.md#adm),
 [bencode](doc/formats.md#bencode),
 bitcoin_blkdat,
 [bitcoin_block](doc/formats.md#bitcoin_block),
@@ -68,9 +66,7 @@ bsd_loopback_frame,
 bzip2,
 [caff](doc/formats.md#caff),
 [cbor](doc/formats.md#cbor),
-[chna](doc/formats.md#adm),
 [csv](doc/formats.md#csv),
-[dolby_metadata](doc/formats.md#dolby_metadata),
 dns,
 dns_tcp,
 [dolby_metadata](doc/formats.md#dolby_metadata),

diff --git a/doc/formats.md b/doc/formats.md
@@ -7,7 +7,6 @@
 |[`aac_frame`](#aac_frame)                                       |Advanced&nbsp;Audio&nbsp;Coding&nbsp;frame                                                                   |<sub></sub>|
 |`adts`                                                          |Audio&nbsp;Data&nbsp;Transport&nbsp;Stream                                                                   |<sub>`adts_frame`</sub>|
 |`adts_frame`                                                    |Audio&nbsp;Data&nbsp;Transport&nbsp;Stream&nbsp;frame                                                        |<sub>`aac_frame`</sub>|
-|[`adm`](#adm)                                                   |Audio&nbsp;Definition&nbsp;Model                                                                             |<sub>`riff`</sub>|
 |`aiff`                                                          |Audio&nbsp;Interchange&nbsp;File&nbsp;Format                                                                 |<sub></sub>|
 |`amf0`                                                          |Action&nbsp;Message&nbsp;Format&nbsp;0                                                                       |<sub></sub>|
 |`apev2`                                                         |APEv2&nbsp;metadata&nbsp;tag                                                                                 |<sub>`image`</sub>|
@@ -26,7 +25,6 @@
 |`avc_sps`                                                       |H.264/AVC&nbsp;Sequence&nbsp;Parameter&nbsp;Set                                                              |<sub></sub>|
 |[`avi`](#avi)                                                   |Audio&nbsp;Video&nbsp;Interleaved                                                                            |<sub>`avc_au` `hevc_au` `mp3_frame` `flac_frame`</sub>|
 |[`avro_ocf`](#avro_ocf)                                         |Avro&nbsp;object&nbsp;container&nbsp;file                                                                    |<sub></sub>|
-|[`axml`](#adm)                                                  |Audio&nbsp;Definition&nbsp;Model&nbsp;<axml>&nbsp;Chunk                                                      |<sub>`riff`</sub>|
 |[`bencode`](#bencode)                                           |BitTorrent&nbsp;bencoding                                                                                    |<sub></sub>|
 |`bitcoin_blkdat`                                                |Bitcoin&nbsp;blk.dat                                                                                         |<sub>`bitcoin_block`</sub>|
 |[`bitcoin_block`](#bitcoin_block)                               |Bitcoin&nbsp;block                                                                                           |<sub>`bitcoin_transaction`</sub>|
@@ -40,9 +38,7 @@
 |`bzip2`                                                         |bzip2&nbsp;compression                                                                                       |<sub>`probe`</sub>|
 |[`caff`](#caff)                                                 |Live2D&nbsp;Cubism&nbsp;archive                                                                              |<sub>`probe`</sub>|
 |[`cbor`](#cbor)                                                 |Concise&nbsp;Binary&nbsp;Object&nbsp;Representation                                                          |<sub></sub>|
-|[`chna`](#adm)                                                  |Audio&nbsp;Definition&nbsp;Model&nbsp;<chna>&nbsp;Chunk                                                      |<sub>`riff`</sub>|
 |[`csv`](#csv)                                                   |Comma&nbsp;separated&nbsp;values                                                                             |<sub></sub>|
-|[`dolby_metadata`](#dolby_metadata)                             |Dolby&nbsp;Metadata&nbsp;(Atmos,&nbsp;AC3,&nbsp;Digital&nbspPlus)                                            |<sub>`riff`</sub>|
 |`dns`                                                           |DNS&nbsp;packet                                                                                              |<sub></sub>|
 |`dns_tcp`                                                       |DNS&nbsp;packet&nbsp;(TCP)                                                                                   |<sub></sub>|
 |[`dolby_metadata`](#dolby_metadata)                             |Dolby&nbsp;Metadata&nbsp;(Atmos,&nbsp;AC3,&nbsp;Dolby&nbsp;Digital)                                          |<sub></sub>|
@@ -184,27 +180,6 @@ Decode value as aac_frame
 ... | aac_frame({object_type:1})
 ```
 
-## adm
-[Audio Definition Model](https://adm.ebu.io/background/what_is_the_adm.html) including 3D Audio.
-
-RIFF / WAV / Broadcast Wave Format (BWF) chunks:
-- `<chna>` Chunk, Track UIDs of Audio Definition Model
--	`<axml>` Chunk, BWF XML Metadata, e.g. for Audio Definition Model ambisonics and elements
-
-### Examples
-Decode ADM configuration from `<chna>` and `<axml>` chunks:
-```
-$ fq -d wav '.chunks[] | select(.id | IN("chna", "axml")) | tovalue' bwf.wav
-```
-
-### Authors
-- [@johnnymarnell](https://johnnymarnell.github.io), original author
-
-### References
-- https://adm.ebu.io/background/what_is_the_adm.html
-- https://tech.ebu.ch/publications/tech3285s7
-- https://tech.ebu.ch/publications/tech3285s5
-
 ## apple_bookmark
 Apple BookmarkData.
 
@@ -625,7 +600,7 @@ including Dolby Atmos, AC3, Dolby Digital \[Plus\], and Dolby Audio Info (e.g. L
 ### Examples
 Decode Dolby metadata from `<dbmd>` chunk:
 ```
-$ fq -d wav '.chunks[] | select(.id | IN("dbmd")) | tovalue' bwf.wav
+$ fq -d wav '.chunks[] | select(.id | IN("dbmd")) | tovalue' adm-bwf.wav
 ```
 
 RIFF / WAV / Broadcast Wave Format (BWF) chunks:
@@ -641,6 +616,7 @@ RIFF / WAV / Broadcast Wave Format (BWF) chunks:
 - https://tech.ebu.ch/publications/tech3285s5
 - https://tech.ebu.ch/files/live/sites/tech/files/shared/tech/tech3285s6.pdf
 - https://github.com/DolbyLaboratories/dbmd-atmos-parser
+- https://github.com/MediaArea/MediaInfoLib/tree/Source/MediaInfo/Audio/File_DolbyAudioMetadata.cpp
 
 ## fit
 Garmin Flexible and Interoperable Data Transfer.
@@ -834,6 +810,7 @@ LevelDB Table.
 - Zstandard uncompression is not implemented yet.
 
 ### Authors
+
 - [@mikez](https://github.com/mikez), original author
 
 ### References

diff --git a/format/riff/dolby_metadata.go b/format/riff/dolby_metadata.go
@@ -83,6 +83,19 @@ var compressionDescMap = scalar.UintMapSymStr{
 	5: "speech",
 }
 
+var downmix5to2DescMap = scalar.UintMap{
+	0: {Sym: "not_indicated", Description: "Not indicated (Lo/Ro)"},
+	1: {Sym: "loro", Description: "Lo/Ro"},
+	2: {Sym: "ltrt_dpl", Description: "Lt/Rt (Dolby Pro Logic)"},
+	3: {Sym: "ltrt_dpl2", Description: "Lt/Rt (Dolby Pro Logic II)"},
+	4: {Sym: "direct_stereo_render", Description: "Direct stereo render"},
+}
+
+var phaseShift5to2DescMap = scalar.UintMap{
+	0: {Sym: "no_shift", Description: "Without Phase 90"},
+	1: {Sym: "shift_90", Description: "With Phase 90"},
+}
+
 var bitstreamModeMap = scalar.UintMapDescription{
 	0b000: "main audio service: complete main (CM)",
 	0b001: "main audio service: music and effects (ME)",
@@ -105,10 +118,10 @@ var binauralRenderModeMap = scalar.UintMapSymStr{
 }
 
 var warpModeMap = scalar.UintMap{
-	0: {Sym: "normal"},
-	1: {Sym: "warping"},
-	2: {Sym: "downmix_dolby_pro_logic_iix"},
-	3: {Sym: "downmix_loro"},
+	0: {Sym: "normal", Description: "possibly: Direct render"},
+	1: {Sym: "warping", Description: "possibly: Direct render with room balance"},
+	2: {Sym: "downmix_dolby_pro_logic_iix", Description: "Dolby Pro Logic IIx"},
+	3: {Sym: "downmix_loro", Description: "possibly: Standard (Lo/Ro)"},
 	4: {Sym: "not_indicated", Description: "Default warping will be applied"},
 }
 
@@ -236,29 +249,35 @@ func parseAudioInfo(d *decode.D) {
 }
 
 func parseDolbyAtmos(d *decode.D) {
-	// TODO: both these are fixed size null terminated strings?
 	d.FieldUTF8NullFixedLen("atmos_dbmd_content_creation_preamble", 32)
 	d.FieldUTF8NullFixedLen("atmos_dbmd_content_creation_tool", 64)
 	d.FieldStruct("version", func(d *decode.D) {
 		d.FieldU8("major")
 		d.FieldU8("minor")
-		d.FieldU8("micro")
+		d.FieldU8("patch")
 	})
+	// TODO: All these unknowns? (mostly from MediaInfoLib, also Dolby repo)
+
+	d.FieldRawLen("unknown0", 21*8)
+
+	d.FieldRawLen("unknown1", 1)
+	d.FieldU3("downmix_5to2", scalar.UintSym("unknown"), downmix5to2DescMap)
+	d.FieldRawLen("unknown2", 2)
+	d.FieldU2("phaseshift_90deg_5to2", scalar.UintSym("unknown"), phaseShift5to2DescMap)
 
-	// TODO: what is this?
-	d.FieldRawLen("unknown0", 53*8)
+	d.FieldRawLen("unknown3", 12*8)
 
-	d.FieldU8("warp_mode", warpModeMap)
+	d.FieldRawLen("bed_distribution", 2)
+	d.FieldRawLen("reserved0", 3)
+	d.FieldU3("warp_mode", warpModeMap)
 
-	// TODO: what is this?
-	d.FieldRawLen("unknown1", 15*8)
-	d.FieldRawLen("unknown2", 80*8)
+	d.FieldRawLen("unknown4", 15*8)
+	d.FieldRawLen("unknown5", 80*8)
 }
 
 func parseDolbyAtmosSupplemental(d *decode.D) {
 	d.FieldU32("dasms_sync", d.UintAssert(0xf8726fbd), scalar.UintHex)
 
-	// TODO: wav.go sets LE default i think?
 	objectCount := int64(d.FieldU16("object_count"))
 	d.FieldU8("reserved")
 

diff --git a/format/riff/dolby_metadata.md b/format/riff/dolby_metadata.md
@@ -20,3 +20,4 @@ RIFF / WAV / Broadcast Wave Format (BWF) chunks:
 - https://tech.ebu.ch/publications/tech3285s5
 - https://tech.ebu.ch/files/live/sites/tech/files/shared/tech/tech3285s6.pdf
 - https://github.com/DolbyLaboratories/dbmd-atmos-parser
+- https://github.com/MediaArea/MediaInfoLib/tree/Source/MediaInfo/Audio/File_DolbyAudioMetadata.cpp