| WA8LMF Home Page | Main Ham Radio Page | Main APRS Page | Updated 01 June 2020 |
This program allows you to automatically download and stitch bitmap tiles from Google Maps, Microsoft Virtual Earth, Yahoo Maps or Open Street Map into seamless map images of virtually any size. It allows you to download either street map or satellite views from any of these sources.
The images captured by this program are non-projected (i.e. simple rectangular X/Y grid with latitude and longitude lines at right angles) at least for distances of 85-100 miles (130-160 KM) across. The assembled maps are suitable for use directly with any APRS program that can use static (fixed non-zooming) images as maps, or as underlays for the Precision Mapping Server plugin for UIview. The images align perfectly with the non-projected vector maps produced by Precision Mapping in UIview.
Note that when used with UIview, downloaded/tiled images can be far larger (in pixels) than the resolution (in pixels) of your computer display system. UIview will "automagically" create a "viewport" window that shows a portion of the oversized map image. You can then scroll (but not zoom) around the entire map. UIview DOS NOT downsample the map image into an illegible blur in an effort to fit all of it onto the screen at once. If you reduce the color depth of map images to 256 or 16 colors, UIview can easily handle 4000x4000 pixel images or larger. iIe. the equivalent of "Ultra-HD" a.k.a. "Quad-HD" images, even if the computer display is far lower resolution -- 1024x768 XGA or 1920x1080 "full HD".
Universal Maps Downloader a.k.a. "UMD" is a $59.95 shareware program. The free "trial" download has limited functionality; it will download maps at a resolution suitable for regional coverage. For higher resolution downloads suitable for street-level applications, it requires registration. The program is available from
<http://www.allmapsoft.com/umd>
The program has a total installed footprint of about 5 MB. Of course, you will want considerably more space for captured map images. UMD actually consists of three separate .EXE files: the main program that does the downloading of a specified area, a "Map Viewer" that can display the collected tiles as a single large image, and a "Map Combiner" that stitches the downloaded tiles into a single large .BMP file.
When you start the main program, you are greeted by this screen. The un-calibrated "Zoom level:" slider increases/decrease the linear resolution about 2:1 for each step; i.e. quadruples or quarters the number of pixels in the resulting image. The actual size of each downloaded tile is a constant 256x256 pixels regardless of resolution requested. As you increase the resolution, the number of these tiles downloaded (for a given area defined by a pair of lat/long values) increases. Requesting a county-sized area or larger, at street-level resolution, will result in the download of hundreds or thousands of tiles.
The latitude & longitude coordinates that select the area to be captured are entered in degrees and decimal degrees (DD.dddddd) -- not degrees-minutes-seconds (DDMMSS), or degrees and decimal minutes (DD MM.mmmm). A converter tool is available from the menu to convert DDMMSS to DD.dddddd. Annoyingly it won't convert the default GPS (and APRS) format of DD MM.mmmm. You can enter lat/long to any number of decimal places (at least 10). Since UMD always downloads fixed 256x256 pixel tiles, you may get an area slightly larger than requested regardless of the precision of your coordinates.
(A separate tool that converts between all
three coordinate formats is downloadable from my website.
)
The "Maps type:" pull-down allows you to choose the source of your images. Successive releases of the program every few months keep expanding the range of choices.
The "Task name" entry box above "Maps type:" allows you to save all the settings on the screen to a named file. This is useful for downloading images from several different sources with exactly the same lat/long and zoom settings. Later, the lat/long values can be copied/pasted into .SAT or .INF calibration files for maps used in various programs. These will only be approximate starting points that will need some trial & error "tweaking" to bring the map into precise alignment (since the actual captured areas will always be slightly larger than requested).
With all the settings selected and/or entered, you click the
"Start" button. Depending on the number of tiles requested (which is computed
and displayed in the lower left corner), the download time will range from
nearly instantly to several minutes or more. In this screen shot, the resolution is
set to the default "Zoom Level 12". This is the most detailed that the
unregistered/trial version of the program will accept.
The log file in the right window shows a list of the tiles captured. This
data is also automatically saved to the file
nnnn_log.txt where
nnnn is the Task Name assigned to the capture. This file is saved into the same
directory specified for "Path to save:"
If you you scroll the log display back to the top (or open the log file in Notepad), you will see two sets of coordinates representing the upper-left and lower-right corners of the captured map area. The first set are the values you entered. The second set (circled in the screen shot below) are the actual area captured, resulting from rounding up to boundaries of the tiles required to capture the desired area. The second set of coordinates (circled below) are the exact values you need to precisely calibrate the map for use in APRS programs! Just copy and paste these values into the appropriate .INF or .SAT file. (You may have to convert the DDD.dddddd decimal degrees format into the GPS/APRS format of DD MM.mmmmmm format for some programs.)
run.
The downloaded tiles are saved as .PNG files, but the "Map Combiner" auto-stitcher produces a .BMP file as it's output. The default saved image is in 24-bits-per-pixel photographic "high-color" format which results in unnecessarily large files. Reducing the color depth to 256 colors (8-bits-per-pixel) with an image editor program such as Windows Paint or IrfanView, and then resaving the file, will cut the file size to one-third of the original. I used the freeware IrfanView utility to convert these to .GIF format (which intrinsically is limited to 256 colors or less). The links below provide examples of the map images produced by the various sources.
Some of these samples are very large (2000x3000
pixels or more) images. Some browsers will attempt to downsize oversized
images to fit the browser window. Turn off this automatic resizing to
see the highest-quality images. You will then have to scroll
horizontally and/or vertically to view the entire map.
Note that most APRS programs (UIview, APRSplus, etc) will allow you to use
images far larger than your screen; your application becomes a scrollable view
port showing part of a much larger image. I have successfully used
images of 4000x5000 pixels with UIview running on a 1024x768 XGA screen. The
key is to reduce the color depth of images to only 16 or 256-colors from the
default 24-bit photographic "high-color"; this cuts the amount of image data
the program has to deal with to one-third.
Warning! Some of these sample
GIF images are very large files. Most are between 1 and 5 megabytes. A
couple are around 10 MB. They will take significant time to download.
Each sample opens in a new window (tab in modern browsers) for quick comparison.
Greater Los Angeles Regional
View (About 85 Miles Across)
|
Captured From Google Maps |
| Streets Zoom Level 10 (614 KB) |
| Streets Zoom Level 11 (1.9 MB) |
| Streets Zoom Level 12 (5.8 MB) |
| Satellite Zoom Level 10 (1 MB) |
| Terrain Zoom Level 11 (3 MB) |
| Terrain Zoom Level 12 (9.8 MB) - HUGE!) |
Captured From Microsoft Virtual Earth |
| Streets Zoom Level 11 (1.9 MB) |
| Streets Zoom Level 12 (5.9 MB) |
| Satellite Zoom Level 11 (3.4 MB) |
| Hybrid [Streets & Satellite] Zoom Level 11 (3 MB) |
| Hybrid [Streets & Satellite] Zoom Level 12 (11.3 MB - HUGE!) |
Captured From Yahoo Maps |
| Streets Zoom Level 11 (1.9 MB) |
| Streets Zoom Level 12 (6.3 MB) |
| Satellite Zoom Level 11 (3.1 MB) |
Captured From Open Street Maps |
| Streets Zoom Level 11 (1.7 MB) |
| Streets Zoom Level 12 (5.6 MB) |
Pasadena, CA City Scale View (About 6 Miles
Across)
|
Google Maps |
| Streets Zoom Level 12 (140 KB) |
| Streets Zoom Level 14 (544 KB) |
| Terrain Zoom Level 12 (220 KB) |
| Terrain Zoom Level 14 (1.3 MB) |
Microsoft Virtual Earth |
| Hybrid [Streets & Satellite] Zoom Level 12 (140 KB) |
| Hybrid [Streets & Satellite] Zoom Level 14 (1.5MB) |
Yahoo Maps |
| Streets Zoom Level 12 (160 KB) |
| Streets Zoom Level 14 (160 KB) |
White Paper: The PBP File Format and Content Distribution Mechanisms Date: October 26, 2023 Subject: Technical Analysis of the PlayStation Portable PBP Container Format Keywords: PBP, PSP, PlayStation, Firmware, Homebrew, Digital Rights Management, File Structure. Abstract This paper provides a technical examination of the PBP (PlayStation Portable Bundle) file format. Originally developed by Sony Computer Entertainment for the PlayStation Portable (PSP) handheld system, the PBP format serves as a versatile container for executable data. This document details the internal architecture of the PBP file, the protocol mechanisms for downloading and verifying these files via the PlayStation Network, and the implications of the format on digital rights management (DRM) and the homebrew community. 1. Introduction The PBP file extension denotes an archive format utilized primarily by the PlayStation Portable (PSP) and, in later iterations, the PlayStation Vita and PlayStation 3 (for emulation purposes). Unlike standard executable formats (such as ELF or PE), a PBP file acts as a wrapper or container, housing various segments required to launch a game, application, or system firmware update. Understanding the PBP format is essential for digital preservationists, software developers working within the homebrew ecosystem, and security researchers analyzing the PlayStation ecosystem's content delivery architecture. 2. Technical Structure and Architecture A PBP file is structurally defined by a header that points to various data sections. The format allows for the consolidation of executable code and multimedia assets into a single binary blob. 2.1 Header Specification The PBP header is typically 40 bytes (0x28) in size and follows a specific layout:
Signature (4 bytes): A null-terminated string 0x50425000 (PBP\0), identifying the file format. Version (4 bytes): Indicates the version of the PBP format (usually 0x00010000 ). Offset Table (8 x 4 bytes): The header contains eight pointers, each indicating the absolute offset within the file where a specific section begins. If a section is not present, the offset is usually zero or identical to the subsequent section.
2.2 Data Sections The header offsets point to six distinct parametric sections and a data section:
PARAM.SFO (Parameter File): Contains metadata about the content, including the title, serial ID (e.g., UCAS-40123), parental control level, and firmware version requirements. ICON0.PNG: A 144x80 pixel image used as the application icon in the XMB (XrossMediaBar) interface. ICON1.PMF: (Optional) A video file in PMF (PlayStation Movie Format) used for animated icons. PIC0.PNG: (Optional) A background screenshot or preview image. PIC1.PNG: (Optional) A larger background image used in the UI. SND0.AT3: (Optional) Audio file (ATRAC3 format) for background music in the menu. DATA.PSP: The core executable payload. pbp files download
In standard games, this is a signed, encrypted executable. In official firmware updates, this contains the updater modules. In homebrew, this is an unencrypted ELF binary.
DATA.PSAR: (Optional) A large archive section. This typically contains the bulk of the game data or, in the case of firmware updates, the actual firmware modules.
3. Download Mechanisms and Distribution Protocols The process of downloading PBP files involves a complex interaction between the client device (PSP/Vita) and the Sony server infrastructure. 3.1 Official Distribution (PlayStation Network) Official PBP files are distributed via Sony's proprietary update servers and the PlayStation Store. White Paper: The PBP File Format and Content
Firmware Updates: The PSP system accesses specific URLs (e.g., http://du01.psp.update.playstation.org/update/psp/ ) to check for updates. The server returns an XML response containing the version number and a download link for the EBOOT.PBP . Content Acquisition: Games purchased via the PlayStation Store are downloaded via a secure SSL/TLS channel. The downloaded packages are often wrappers containing the PBP files. DRM Implementation: Official PBP files downloaded from the PlayStation Store utilize DRM mechanisms. While the file structure remains similar, the executable code inside DATA.PSP is encrypted using keys specific to the user's account or the device ID, a system often referred to as "NPDRM" (Network Platform DRM).
3.2 The "EBOOT" Naming Convention It is crucial to note that while the file extension is .PBP , these files are almost universally named EBOOT.PBP when placed in the directory structure of the PSP memory card. The system kernel identifies the file not by the extension, but by the header signature once the file is accessed by the bootloader. 4. Digital Rights Management (DRM) and Security The PBP format was central to Sony's security architecture for the PSP. 4.1 Encryption Official PBP files contain encrypted payloads. The DATA.PSP section typically consists of an ELF file encrypted with a Sony-proprietary algorithm. The bootloader inside the PSP contains the decryption keys necessary to load and execute the code. 4.2 KIRK and Spock Engines The PSP hardware includes cryptographic engines (KIRK and Spock) that handle the decryption of PBP contents in real-time. This hardware-level enforcement ensured that simply downloading a game file was insufficient to play it on a standard, unmodified device; the file had to be signed by Sony’s private keys. 4.3 The Root Key Leak In 2010, a significant security breach occurred when the signing keys for the PS3 (which overlapped with PSP encryption) were leaked. This allowed developers to create PBP files with valid signatures that the PSP hardware would accept, bypassing DRM restrictions. This led to a proliferation of "Signed Homebrew" that could run on official firmware without modification. 5. Usage in Homebrew and Preservation The PBP format remains a standard in the retro-gaming and homebrew communities. 5.1 Homebrew Development Developers use tools like pack-pbp (part of the PSPSDK) to compile their code into a valid PBP file. These files are structurally identical to official files but contain unencrypted executable code. 5.2 Game Conversion (POPStarter) The PSP is capable of emulating the original PlayStation (PS1). Users often convert PS1 ISO files into PBP format (often called EBOOT.PBP ) to play them on the PSP. This involves compressing the ISO and injecting it into the DATA.PSAR section, accompanied by a specialized loader executable in the DATA.PSP section. 5.3 File Compression Because PSP storage media (Memory Sticks) were expensive and limited in capacity, the PBP format supports compression (often utilizing GZIP) within its data sections to minimize file size. 6. Conclusion The PBP file format represents a robust, containerized approach to software distribution that predates modern container formats used in mobile operating systems today. Its design efficiently bundles metadata, assets, and executable code into a single manageable package. While its primary usage has shifted from official commercial distribution to community-driven homebrew and digital preservation, understanding the architecture of the PBP file provides critical insight into the software engineering and security paradigms of the mid-2000s handheld gaming era.
References
PlayStation Portable SDK Documentation (PSPSDK). Silver, J. (2011). Reverse Engineering the PlayStation Portable . various community documentation on the PSDevWiki. Sony Computer Entertainment. (2005). PSP Software Development Kit Manual .
What is a PBP file? A PBP (PSP Game) file is a compressed format originally for PlayStation Portable games. However, it’s also used for PS1 games because: