You'll never need this.
VNMGF is a proprietay sprite packing format used by Viacom circa 1995. To my knowledge, its only usage in the wild is via Beavis & Butthead's Virtual Insanity from that same year.
As for why I made this? I wanted to re-make the Hock-A-Loogie mini-game from Virtual Insanity in Godot for fun and as a learning exercise. So, I downloaded a copy of the original game from some dark, long forgotten corner of the internet. Inside were the sound files and some sort of .000 file that didn't match any file signature that I could find. I was confident the image data was packed in there, I just needed to figure out what format it was. I couldn't find any file formats whose signatures matched, alas.
Luckily, literally one other person on the internet knows about these files and had already reverse engineered the format (http://www.shikadi.net/moddingwiki/Viacom_New_Media_Graphics_File_Format) back in 2015.
So, I spent some time converting the extractor to Go (based on the C code in the link above) to extract all the images.
The data does not seem to come out perfect. There are a few images with odd pixels missing near the right edge. But, it's 99% accurate and the issues are easily fixed manually.
The original BBLOOGIE.000 file is included in the data dir along with the exported images. Knock yourself out.
I am copying this information from Shikadi (see the link above) for the sake of preservation.
| Data Type | Description |
|---|---|
| UINT32LE | Signature: File Signature (should match 0x564E4D1A aka "VNM\x1A") |
| UINT32LE | Flags: Possibly file information flags. |
| UINT32LE | Size: Size Of Data |
| UINT32LE | OffsetPal: Offset to Pal Data. |
| UINT32LE | OffsetUnknown1: Offset to currently Unknown Data. |
| UINT32LE | OffsetUnknown2: Offset to currently Unknown Data. |
| UINT32LE | OffsetImages: Offset to VNM Image index array. |
| UINT32LE | PalIndexFirst: First valid index in Color Palette. |
| UINT32LE | PalIndexSize: Count of Palette indexes stored in file at OffsetPal. |
| UINT32LE | ImageCount: Count of Images stored in file at OffsetImages. |
| Data Type | Description |
|---|---|
| UINT32LE | Offset: Offset in file to where raw image data starts. |
| UINT32LE | Type: 0 = Bitmap, 1 = Sprite |
| UINT32LE | Width: Width of this Image |
| UINT32LE | Height: Height of this Image. |
| UINT32LE | XPos: XPos of this Image. |
| UINT32LE | YPos: YPos of this Image. |
The file consists of the VNM File Header followed by VNM Image data.
Each VNM Image starts at a location in the file specified by the array found at OffsetImages. This array is ImageCount in length and each entry specifies the position in the file for a specific VNM Image.
A VNM Image consists of metadata (width, height, etc.) about a given image as well as an Offset pointing to yet another array based index. This index has an entry for each row in the image. Thus, to rebuild an image you traverse the row index array and gather up the data starting from each position the index specifies, grabbing Width bytes.
If the image is a Bitmap, you can put those bytes together and you're finished.
However, if the image is a Sprite, you must also expand the transparent sections which are flagged via an escape code equal to 0x100 (256) minus the image's width. When one of these bytes is encountered, you subtract the value at the current pixel byte from 0x100 to determine how many transparent should be added before moving on.
It looks something like:
F800 19 FD00 18F700 0F FB
F901 18 19 FF00 18FF0117 19 F801 0E 10 FD00 0F
FA07 19 18 18 17 18 19 17 19 F801 0E 10 FD00 0F
FA08 19 17 19 19 17 19 18 18 19 FF00 19 FB05 0F 11 0F 11 0F 10
FB0B 19 18 17 19 18 17 18 18 17 19 17 18 FB05 10 11 10 11 0E 11
FB0C 18 18 19 19 18 17 18 19 17 19 17 19 18 FC04 11 0E 0F 10 0E FF
FC0D 19 17 19 18 19 19 17 18 19 17 18 17 19 18 FD05 10 0E 11 10 11 0F FF
FC0D 19 17 19 18 19 17 18 19 17 18 19 17 19 17 FD05 10 0F 11 11 10 11 FF
FC0D 18 17 19 17 18 17 19 18 17 18 19 18 19 19 FC04 11 10 10 0F 10 FF
FC0E 18 18 19 17 17 19 19 18 17 18 19 19 18 19 18 FD03 11 0F 0F 10 FE
FC0E 19 18 19 18 19 18 19 18 17 18 19 18 17 18 19 FD02 11 11 10 FD
FC0E 19 18 19 18 19 17 19 19 17 18 19 17 17 19 19 FD02 11 10 0F FD
FC0E 19 17 18 10 0F 18 19 17 18 19 19 18 17 19 19 FD02 11 0F 10 FD
FC0E 18 17 19 0F 0E 0F 18 18 19 0F 10 18 17 19 18 FD02 11 0F 10 FD
FC0E 19 17 19 0E 0E 0E 0E 0E 0E 0E 0E 0F 18 19 18 FD02 11 0E 10 FD
FC0E 19 18 10 0E 0F 0F 0E 0E 0E 0E 0F 0F 10 17 19 FD02 11 0E 10 FD
FC0E 18 19 0F 10 11 11 10 0E 0F 10 11 10 0F 17 19 FD02 11 0E 10 FD
FC0E 17 19 0E 0F 10 10 11 0F 10 11 10 0F 0E 18 19 FD02 11 0E 10 FD
FC0E 19 17 10 0E 0F 0E 0F 0E 10 0F 0E 0E 0E 19 18 FD02 11 0E 10 FD
FC0E 18 11 0F 0E 0E 0F 10 0E 0E 10 0F 0E 0E 19 17 FD02 11 0E 10 FD
FB0D 10 0F 0E 0E 10 11 0F 11 10 10 0E 0F 10 17 FD02 10 0E 11 FD
FB0C 11 10 0F 0E 0E 0F 10 10 0F 0F 0E 0F 0FFC02 10 0E 11 FD
FA0B 11 0F 0E 0E 0E 0F 0F 0F 0E 0E 0F 11FC02 0E 0F 11 FD
FA0B 11 10 0F 0E 0F 20 10 20 0F 0E 0F 11FD02 10 0E 10 FC
F90A 10 0F 0E 10 20 20 20 10 0F 10 11FD02 0E 0F 11 FC
F909 11 0F 0E 11 15 16 15 11 0F 10FD02 10 0E 10 FB
F909 11 0F 0E 11 1C 1C 1C 11 0F 11FD02 0E 0F 11 FB
F808 10 0F 10 11 1C 11 10 0F 11FE02 10 0E 10 FA
F807 10 0F 0F 10 11 10 0F 10FE03 10 0E 0F 11 FA
F807 11 10 0F 0E 0F 0E 0F 11FF041B 10 0E 10 11 FA
F70B 11 10 0F 0E 0F 10 11 17 1B 10 0F 11 F9
F70B 11 10 10 10 10 11 17 1B 1A 1B 10 11 F9
F60A 11 10 0F 10 11 1C 1B 1A 1A 1B 1B F9
F70B 1B 1B 10 10 10 1B 1C 1B 1A 1A 1A 1C F9
F90D 1B 1B 1A 1A 1B 1B 1B 1A 1B 1A 1A 1A 1B 1C F9
FA0D 1B 1A 1A 1A 1A 1A 1A 1A 1A 1A 1A 1A 1B 1C F8
FB0E 1B 1A 1A 1A 1A 1A 1A 1A 1A 1A 1A 1A 1A 1B 1C F8
FC0E 1B 1A 1A 1A 1B 1A 1A 1A 1A 1A 1A 1A 1A 1B 1C F7
FC0E 1B 1A 1A 1B 1C 1B 1A 1A 1A 1A 1A 1A 1B 1B 1C F7
FD0F 10 10 1B 1B 1C 1B 1B 1A 1A 1A 1A 1A 1A 1B 1B 1C F7
FD0F 10 0F 10 1C 1C 1B 1A 1A 1A 1A 1A 1A 1A 1B 1B 1C F7
FE03 10 0E 10 11FF0A1C 1B 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
FE02 10 0F 11 FE0A1C 1B 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
FF03 10 0E 10 11 FE0A1C 1B 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
FF02 10 0F 11 FD0A 1C 1B 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
FF02 10 10 11 FD0A 1C 1B 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
02 10 0F 10 FC0A 1C 1B 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
02 10 0E 11 FC0A 1C 1B 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
02 10 0E 11 FC0A 1C 1B 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
02 10 0E 11 FC0A 1C 1B 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
02 10 0E 11 FD0B1C 1B 1A 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
02 10 0F 11 FD0B1C 1B 1A 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
02 10 10 11 FD0B1C 1B 1A 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
03 10 0F 0F 10 FE0B1C 1B 1A 1A 1A 1A 1A 1A 1A 1A 1B 1C F6
04 11 0E 10 0F 10FF0B1C 1B 1B 1A 1A 1A 1A 1A 1A 1B 1B 1C F6
03 11 0E 0F 11 FE0B1C 1C 1C 1B 1B 1B 1B 1B 1B 1C 1C 1C F6
03 11 0F 0E 10 FE0B22 22 22 21 21 21 21 21 21 21 22 22 F6
FF02 11 11 11 FE0B22 21 21 20 20 20 20 20 20 20 21 22 F6
FA0B 22 21 20 20 20 20 20 20 20 20 21 22 F6
FA0B 22 21 20 20 20 21 20 20 20 20 21 22 F6
FA0B 22 21 20 20 21 22 21 20 20 20 21 22 F6
FA0B 22 21 20 20 21 22 22 21 20 20 21 22 F6
FA0B 22 21 21 21 21 22 22 21 21 21 21 22 F6
F909 11 10 0F 10 11 11 10 0F 10 11 F5
F909 11 0F 0E 0F 11 11 0F 0E 0F 11 F5
F909 11 0F 0E 0F 11 11 0F 0E 0F 11 F5
F909 11 0F 0E 0F 11 11 0F 0E 0F 11 F5
F909 11 0F 0E 0F 11 11 0F 0E 0F 11 F5
F909 11 10 0E 0F 11 11 0F 0E 10 11 F5
F807 11 0E 0F 11 11 0F 0E 11 F4
F807 11 0E 0F 11 11 0F 0E 11 F4
F807 11 0E 0F 11 11 0F 0E 11 F4
F807 11 0E 0F 11 11 0F 0E 11 F4
F807 11 0E 10 11 11 10 0E 11 F4
F802 16 16 16 FE02 16 16 16 F4
F802 16 15 16 FE02 16 15 16 F4
F802 16 15 16 FE02 16 15 16 F4
F802 16 15 16 FE02 16 15 16 F4
F807 1C 1C 1C 1C 1C 1C 1C 1C F4
FA0B 1C 1B 1A 1B 1B 1C 1C 1B 1B 1A 1B 1C F6
FB0D 1C 1B 1A 1B 1B 1C 1C 1C 1C 1B 1B 1A 1B 1C F7
FB04 1C 1C 1C 1C 1C FC04 1C 1C 1C 1C 1C F7