MPO
Overview
MPO = Multi-Picture Object
Document describing the file format used in mpo files: http://www.cipa.jp/english/hyoujunka/kikaku/pdf/DC-007_E.pdf
Nintendo uses a common format for its 3D pictures. MPO is basically two JPG files concatenated in one file. The two JPG files has an EXIF data structure in their headers (This was developed by CIPA).
EXIF is a standard that specifies the formats for images, sound, and ancillary tags used by digital cameras (including smartphones), scanners and other systems handling image and sound files recorded by digital cameras.[1]
Nintendo's EXIF Data Structure
| ID | DESCRIPTION | VALUE |
|---|---|---|
| 0x010F | Manufacturer | Nintendo |
| 0x0110 | Camera | Nintendo 3DS |
| 0x011A | XResolution | 72:1 |
| 0x011B | YResolution | 72:1 |
| 0x0128 | ResolutionUnit | 2 |
| 0x0131 | Software | 00204 |
| 0x0132 | DateTime | YYYY:MM:DD HH:mm:SS |
| 0x0213 | YCbCrPositioning | 2 |
| 0x9000 | ExifVersion | 0220 |
| 0x9003 | DateTimeOriginal | YYYY:MM:DD HH:mm:SS |
| 0x9004 | DateTimeDigitized | YYYY:MM:DD HH:mm:SS |
| 0x9101 | ComponentsConfiguration | [0x01,0x02,0x03,0x00] |
| 0x927C | MakerNote | [DATA - 174 bytes] (yet to be understood) |
| 0xA000 | FlashPixVersion | 0100 |
| 0xA001 | ColorSpace | 1 |
| 0xA002 | PixelXDimension | 640 |
| 0xA003 | PixelYDimension | 480 |
| 0x5041 | InteroperabilityIndex | R98 |
| 0x5042 | ExifInteroperabilityVersion | 0100 |
| 0x1000 | InteroperabilityVersion | JPEG Exif Ver 2.2 |
| 0x501B | ThumbnailData | [DATA - 3000+ bytes] |
| 0x5023 | ThumbnailCompression | 6 |
| 0x502D | ThumbnailXResolution | 72:1 |
| 0x502E | ThumbnailYResolution | 72:1 |
| 0x5030 | ThumbnailTransferFunction | 2 |
| 0x0201 | JPEGInterchangeFormat | 682 |
| 0x0202 | JPEGInterchangeFormatLength | 3000+ |
| 0x5091 | ChrominanceTable | [DATA - 128 bytes] |
| 0x5090 | LuminanceTable | [DATA - 128 bytes] |
Nintendo's EXIF MakerNote Tag
This still need to be figured out:
The MakerNote is made with Tiff Exif information (Big Endian)
first 2 bytes are the IFD Count (IFD is a 12 byte tag), Regulary there are 2 IFDs.
IFD structure
| Tag | Type | Count/Value | Value/Offset |
|---|---|---|---|
| 2 bytes | 2 bytes | 4 bytes | 4 bytes |
Nintendo's IFDs
| Tag | Desc | Type | Count/Value | Value/Offset |
|---|---|---|---|---|
| 0x1100 | Software-specific data | 7-Undefined | Count | Count=1 ? Value : Offset |
| 0x1101 | Nintendo 64byte Note | 7-Undefined | Count | Offset |
After the IFDs comes a 4 byte Zero ( {0,0,0,0} ).
And then the Data the IFDs point at (if at all)
Nintendo's 64Byte Note
| Offset | Description | Type | Default Value |
|---|---|---|---|
| 0 | Magic | Byte[4] | {'3','D','S','1'} |
| 24 | Console identifier? | Int | ? |
| 38 | Unknown | Unknown | Unknown |
| 40 | 3D Parallax* | NegInt? | ? |
| 48 | Category? | Int? | 0x02000 for a man, 0x04000 a woman, 0x10000 a mii... |
- The 3D Parallax value is the distance that the right image needed to move in order to get focus.
My formula to get that value isn't so good but here it is:
x = (lsb - 0xC0) << 8 + msb;
Parallax = - round( 2 ^ (x/128 + 2) )
If someone makes sense of this, please explain or maybe correct..