VGF File Format Notes

Section Alignment

VGF files written with format version 0.4.3 or later align each section offset to an 8-byte boundary. Decoders remain compatible with older files whose section offsets were not guaranteed to be 8-byte aligned.

Model Constants Section

New VGF files store the Model Constants Section as a compact raw byte section. Older files can still contain the legacy FlatBuffers ConstantSection layout; the decoder keeps support for that legacy representation.

The current raw constants layout is version CONST00:

Offset	Size	Field	Description
0	8	version	Fixed bytes C O N S T 0 0 \0.
8	8	count	Number of constant metadata records.
16	count * 24	metadata	Fixed-size ConstantMetaDataV00 records.
16 + count * 24	remaining bytes	payload	Raw constant data bytes.

Each ConstantMetaDataV00 record is 24 bytes:

Offset	Size	Field	Description
0	4	mrt_index	Model Resource Table index for the constant resource.
4	4	sparsity_dimension	Sparse dimension, or -1 for a non-sparse constant. Values below -1 are invalid.
8	8	size	Constant data size in bytes, excluding any padding.
16	8	offset	Offset in bytes from the start of the payload region.

Constant payload entries are stored as raw bytes. The encoder pads each payload entry to an 8-byte boundary, but size always describes the unpadded constant data length returned by the decoder.

Caution

The raw constants section stores fixed-width integer fields and payload bytes without endian conversion. The target host and the host that created the VGF file must use the same endianness.