Struct Capabilities

internal/attachments/processor.go:77–98

Capabilities describes the static capability profile of a Processor. It's safe to embed in HTTP responses — nothing here changes between requests, so callers can cache for the lifetime of the binary.

// It's safe to embed in HTTP responses — nothing here changes between
// requests, so callers can cache for the lifetime of the binary.
type Capabilities struct {
	// ImageFormats are the canonical lowercase format names the backend
	// can decode AND encode (i.e. fully supports for transformation).
	// Pure-Go: ["png", "jpeg", "gif", "bmp", "tiff"]; libvips adds
	// "webp", "avif", "heic" on top.
	ImageFormats []string `json:"image_formats"`

	// CanTranscode reports whether the backend can re-encode between
	// formats. Pure-Go is true (it can decode any supported format and
	// encode to PNG / JPEG); libvips is also true. Effectively a
	// future-proofing flag — false would indicate a degraded build.
	CanTranscode bool `json:"can_transcode"`

	// MaxPixels is the hard ceiling on input image area (width * height).
	// Decode rejects bigger images before allocating decoded pixel
	// buffers — the rejection is on raw dimensions read from the file
	// header, not on the decoded buffer. 64 megapixels (8000 * 8000)
	// is generous enough for high-end DSLRs and low enough that the
	// decode buffer (~256 MiB at 4 bytes/pixel) doesn't OOM the server
	// under concurrent uploads.
	MaxPixels int `json:"max_pixels"`
}

// MaxPixelsDefault is the default value used by the pure-Go backend.
// Public so the Capabilities struct's MaxPixels field has a single