Capture services

caps:a

This is "nn::capsrv::sf::IAlbumAccessorService".

Cmd	Name
0	GetAlbumFileCount
1	GetAlbumFileList
2	LoadAlbumFile
3	DeleteAlbumFile
4	StorageCopyAlbumFile
5	IsAlbumMounted
6	GetAlbumUsage
7	GetAlbumFileSize
8	LoadAlbumFileThumbnail
9	[2.0.0+] LoadAlbumScreenShotImage
10	[2.0.0+] LoadAlbumScreenShotThumbnailImage
11	[2.0.0+] GetAlbumEntryFromApplicationAlbumEntry
12	[3.0.0+]
13	[3.0.0+]
14	[3.0.0+]
15	[4.0.0+]
16	[4.0.0+]
17	[4.0.0+]
18	[6.0.0+]
100	[5.0.0+]
101	[5.0.0+]
202	[1.0.0-2.3.0] SaveEditedScreenShot
301	GetLastThumbnail
302	[4.0.0+]
401	GetAutoSavingStorage
501	GetRequiredStorageSpaceSizeToCopyAll
1001	[3.0.0+]
1002	[3.0.0+]
1003	[4.0.0+]
8001	ForceAlbumUnmounted
8002	ResetAlbumMountStatus
8011	RefreshAlbumCache
8012	GetAlbumCache
8013	[4.0.0+]
8021	[2.0.0+] GetAlbumEntryFromApplicationAlbumEntryAruid
10011	SetInternalErrorConversionEnabled
50000	[6.0.0+]
60002	[4.0.0+]

Cmd1002: Takes a total of 0x38-bytes of input, two type-0x5 input buffers, and returns 0x20-bytes of output. [4.0.0+] No longer returns output, and now takes the following buffers instead: type-0x16, type-0x46, and type-0x6.

Cmd60002: Takes a total of 8-bytes of input, a PID, and returns an #IAlbumAccessorSession.

IAlbumAccessorSession

This is "nn::capsrv::sf::IAlbumAccessorSession".

This was added with [4.0.0+].

Cmd	Name
2001
2002
2003
2004
2005
2006
2007
2008

caps:c

This is "nn::capsrv::sf::IAlbumControlService", previously "nn::capsrv::sf::ICaptureControllerService" with [1.0.0].

Cmd	Name	Notes
[1.0.0] 1
[1.0.0] 2
33	[7.0.0+]
[1.0.0] 1001
[1.0.0] 1002
[1.0.0] 1011
2001
2002
2011	[2.0.0+]
2012	[2.0.0+]
2013	[2.0.0+]
2014	[2.0.0+]
2101	[2.0.0+]	Takes an input u8 and u64, returns a 0x18-byte struct.
2102	[2.0.0+]
[2.0.0-3.0.2] 2201
2202	[4.0.0+]
2301	[2.0.0+]
2302	[4.0.0+]
60001	[4.0.0+]	Takes a total of 8-bytes of input and a PID, returns an #IAlbumControlSession.

Cmd33

Takes an input u64 #ShimLibraryVersion, an u64 AppletResourceUserId, and a PID, no output.

This is used by caps:su SetShimLibraryVersion.

IAlbumControlSession

This is "nn::capsrv::sf::IAlbumControlSession".

This was added with [4.0.0+].

Cmd	Name	Notes
2001
2002
2003
2004
2005
2006
2007
2008
2401
2402
2403
2404
2405
2406	[7.0.0+]
2411
2412
2413
2414
2421
2422
2424
2431
2433
2434

caps:u

This is "nn::capsrv::sf::IAlbumApplicationService".

This was added with [5.0.0+].

Cmd	Name
32	[7.0.0+] #SetShimLibraryVersion
102	GetAlbumFileList0AafeAruidDeprecated
103	DeleteAlbumFileByAruid
104	GetAlbumFileSizeByAruid
105	DeleteAlbumFileByAruidForDebug
110	LoadAlbumScreenShotImageByAruid
120	LoadAlbumScreenShotThumbnailImageByAruid
130	PrecheckToCreateContentsByAruid
140	[6.0.0+] GetAlbumFileList1AafeAruidDeprecated
141	[6.0.0+] GetAlbumFileList2AafeUidAruidDeprecated
142	[7.0.0+] GetAlbumFileList3AaeAruid
143	[7.0.0+] GetAlbumFileList4AaeUidAruid
60002	OpenAccessorSessionForApplication

SetShimLibraryVersion

Takes an input u64 #ShimLibraryVersion, an u64 AppletResourceUserId, and a PID, no output.

IAlbumAccessorApplicationSession

This is "nn::capsrv::sf::IAlbumAccessorApplicationSession".

This was added with [5.0.0+].

Cmd	Name
2001	OpenAlbumMovieReadStream
2002	CloseAlbumMovieReadStream
2003	GetAlbumMovieReadStreamMovieDataSize
2004	ReadMovieDataFromAlbumMovieReadStream
2005	GetAlbumMovieReadStreamBrokenReason

ShimLibraryVersion

This is a version field. Official sw uses func nn::capsrv::GetShimLibraryVersion() to load this from a global var, which is then used with various commands.

[7.0.0-8.1.0] This is value 1.

AlbumEntry

Offset	Size	Description
0x0	0x8	Unknown
0x8	0x8	titleID
0x10	0x2	Year
0x12	0x1	Month
0x13	0x1	Day
0x14	0x1	Hour
0x15	0x1	Minute
0x16	0x1	Second
0x17	0x1	Unknown
0x18	0x1	Unknown
0x19	0x1	Unknown
0x1A	0x6	Padding?

This is "nn::capsrv::AlbumEntry". This is a 0x20-byte struct.

The data at offset 0x10 size 0x8 corresponds to each field in the Album entry filename, prior to the "-".

Notes

capsrv is responsible for validating the MACs for screenshots stored on the SD card, if the setting capsrv!enable_album_screenshot_filedata_verification is non-zero.

Screenshots are validated as follows: The JPEG's MAC is extracted from the EXIF maker note, and stored. A timestamp string is generated by calling snprintf(&str, 20, "%04d:%02d:%02d %02d:%02d:%02d", ...); with stored timestamp values. If this doesn't match the timestamp string stored in EXIF, then an error 0xA34CE is returned. Otherwise, the entire JPEG is loaded into memory, and the stored EXIF maker note is cleared to zeroes. Then, an HMAC-SHA256 is computed over the entire JPEG using a hardcoded secret key. if (memcmp(calculated_hmac, stored_hmac, 0x10) == 0), the screenshot is valid, else 0xA3ACE is returned.

In 3.0.0, MAC calculation was changed: now, instead of calculating an HMAC, a plain SHA256 hash is calculated. capsrv basically does screenshot_kek = spl::GenerateAesKek(<hardcoded screenshot_kek_source>); spl::LoadAesKey(screenshot_kek, <hardcoded screenshot_key_source>); MAC = spl::ComputeCmac(hash);

Videos

4.0.0 includes video playback etc support in Album via mp4. These include a JPEG thumbnail, which is used for video "validation". The EXIF is also much larger: the MakerNote is 0x498-bytes, with encrypted data starting at offset +0x8. This encryption uses AES-CTR with hardcoded key/ctr. MAC calculation works the same way as the 3.0.0+ JPEG MAC calculation, except with a different movie_kek_source/movie_key_source.

Note: the Album process itself uses libstagefright for video playback.