You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
Copy file name to clipboardExpand all lines: docs/manifest/understanding.md
+5-6Lines changed: 5 additions & 6 deletions
Display the source diff
Display the rich diff
Original file line number
Diff line number
Diff line change
@@ -1,13 +1,11 @@
1
1
---
2
2
id: understanding-manifest
3
-
title: Working with manifests
3
+
title: Understanding manifests
4
4
---
5
5
6
-
## Understanding manifests
7
-
8
6
The concept of a _manifest_ is central to how Content Credentials work.
9
7
10
-
A collection of manifests (known as a _manifest store_) is attached to an asset. Each manifest contains information about the provenance of the asset. Creating or editing an asset using a C2PA-compliant device or tool (for example Adobe Photoshop) adds a new manifest to the manifest store.
8
+
A collection of manifests (known as a _manifest store_) is attached to an asset. Each manifest contains information about the provenance of the asset. Creating or editing an asset using a C2PA-compliant device or tool (for example, Adobe Photoshop) adds a new manifest to the manifest store.
11
9
12
10
The manifests in the manifest store are not ordered, but the most-recently added manifest is the _active manifest_. The active manifest has content bindings that can be validated with the asset—that is, it's hashed with the asset to ensure its validity.
13
11
@@ -21,17 +19,18 @@ A manifest store can be either:
21
19
In addition, an asset can have a [external manifest store](https://spec.c2pa.org/specifications/specifications/2.2/specs/C2PA_Specification.html#_external_manifests), linked from the asset's metadata, as detailed in the [C2PA specification](https://spec.c2pa.org/specifications/specifications/2.2/specs/C2PA_Specification.html#_embedding_a_reference_to_an_external_manifest). This is sometimes referred to as a _remote manifest_.
22
20
23
21
To determine if an asset has Content Credentials, the SDK checks for the presence of a manifest store in this order:
22
+
24
23
1. In the asset metadata
25
24
1. In a sidebar file.
26
25
1. In a remote manifest.
27
26
28
27
So, for example to see if `foo.jpg` has Content Credentials, the SDK first checks if there's a manifest store in the file itself, then looks for a sidecar file (`foo.c2pa` in the same directory), and finally looks in the asset's metadata for a reference to a remote manifest store.
29
28
30
29
:::info
31
-
Currently, only Adobe has implemented a Content Credentials cloud service to provide access to remote manifest stores, but in theory anyone could do so to provide a publicly-accessible network location for manifests.
30
+
Currently, only Adobe has implemented a Content Credentials cloud service to provide access to remote manifest stores, but in theory anyone could do so to provide a publicly-accessible network location for manifests.
32
31
:::
33
32
34
-
## Binary versus JSON manifest formats
33
+
## Binary versus JSON manifest
35
34
36
35
The manifest as described in the C2PA specification is a binary structure in JPEG universal metadata box format ([JUMBF](https://www.iso.org/standard/84635.html)) that can include JSON and binary data for things like encryption keys and thumbnail images.
0 commit comments