SNP File Format

Infobox file format
name = Snapshot File
icon =
extension = .snp
mime =
owner = Microsoft
type code =
genre = Access report output, multi-page, precise
containerfor = EMF (contained pages)
containedby = CAB (compression wrapper)
extended from =
extended to = The SNP file format is used by Microsoft Access to store Report Snapshots in a single file which can be viewed and printed by the Microsoft [http://www.microsoft.com/downloads/details.aspx?FamilyID=b73df33f-6d74-423d-8274-8b7e6313edfb&DisplayLang=en Snapshot Viewer] , available as a free download from Microsoft (runs on Windows only). This allows report output to be exported and viewed on Windows computers which do not have Microsoft Access installed.

File format

SNP files are based on the Microsoft Compound File Binary Format (CFBF), which is also the basis for the Advanced Authoring Format (AAF) [http://www.aafassociation.org] . CFBF is a reasonably simple container format which can store multiple files, directories and so on. For SNP files, Access uses CFBF to store each page as a separate Enhanced Metafile (EMF)-like format containing all of the graphics commands required to reproduce the page. Since CFBF files are not compressed, Microsoft's CAB format is used to reduce the size of the CFBF, resulting in a compact file format which may be only a few kilobytes in size for each page of text and simple graphics - lines, boxes, etc.

Working with the pages of an SNP file programmatically involves the following steps:

# Extract contents of SNP file using CAB decompression routines (such as the Windows API "SetupDecompressOrCopyFile" from the "SetupAPI" library)
# Open the resulting file "_AccRpt_.snp" as a CFBF file
# Enumerate the files in the CFBF to find the EMF files for each page
# Extract the EMF file(s) from the CFBF for the desired page(s)

The resultant EMF files are suitable for display or import in a number of graphics programs, can be added to Word documents, Powerpoint presentations, etc. This is useful especially because there is limited or no support for SNP files in most places where EMF files "can" be used.

The above can be implemented in Visual Basic for Applications, which gives Access developers the ability to create custom report interfaces by loading the EMF files into Image objects and so on.

Disclaimer & license

The investigation of the SNP file format which lead to the above information was conducted with information and tools which are freely available online. The author therefore believes that the above does not represent any breach of copyright or infringement on the intellectual property of any person or organization. As such the Author explicitly agrees to license this article under the .

Licensing information for the SNP [http://www.microsoft.com] , CAB [http://www.microsoft.com] and AAF [http://www.aafassociation.org] are probably available from their respective creators/owners.

References

The following references relate to the Compound File Binary Format format:
* cite web
accessdate = 2006-05-22
format = PDF
url = http://sc.openoffice.org/compdocfileformat.pdf
title = Microsoft Compound Document File Format
work = OpenOffice.org CFBF description
* cite web
accessdate = 2006-05-22
format = PDF
url = http://www.aafassociation.org/html/specs/aafcontainerspec-v1.0.1.pdf
title = Advanced Authoring Format Low-Level Container Specification
work = Microsoft Structured Storage version 3 specification (PDF)

The following reference relates to the EMF-like nature of the SNP File Format:
* cite web
accessdate = 2008-09-27
format = HTML
url = http://social.msdn.microsoft.com/Forums/en-US/os_binaryfile/thread/858f2a6e-d13b-4034-a841-4c53d4063dfc
title = Is Microsoft Access Snapshot considered EMF?
work = MSDN Forum discussion of SNP file format

ee also

* Advanced Authoring Format (AAF)
* Cabinet (file format)
* Compound File Binary Format (CFBF)

External links

* Microsoft [http://www.microsoft.com/downloads/details.aspx?FamilyID=b73df33f-6d74-423d-8274-8b7e6313edfb&DisplayLang=en Snapshot Viewer]