mirror of
https://github.com/gohugoio/hugo.git
synced 2026-08-24 07:18:54 +00:00
Bjørn Erik Pedersen
90d9f812b2
The encode/decode is implemented in a WebAssembly module built from a small C wrapper around libavif. Bundled libraries (statically linked, compiled with the WASI SDK): * libavif v1.4.1 (container + codec glue) * libaom v3.14.1 (AV1 encoder + decoder) * dav1d 1.5.3 (AV1 decoder) * libyuv (Chromium pin) for color conversion * parson for JSON message passing across the wasm boundary HDR handling on the encoder: * SDR images are written as BT.709 / sRGB / BT.601 (8-bit). * 10-bit and up are written as BT.2020 primaries with PQ (SMPTE ST 2084) transfer and BT.2020-NCL matrix coefficients, signalled via CICP. * Adobe-style SDR+gainmap inputs (e.g. Lightroom HDR exports) are baked into a single true-HDR image in BT.2020/PQ at 10-bit, with the CLLI (Content Light Level Information) box carried through so HDR-capable clients can tone-map correctly. Limitations: * Animated input (animated WebP/GIF) is collapsed to its first frame when re-encoded as AVIF; animated AVIF output is not yet supported. Fixes #7837
85 lines
2.8 KiB
Go
85 lines
2.8 KiB
Go
// Copyright 2025 The Hugo Authors. All rights reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Package himage provides some high level image types and interfaces.
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package himage
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import "image"
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// AnimatedImage represents an animated image.
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// This is currently supported for GIF and WebP images.
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type AnimatedImage interface {
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image.Image // The first frame.
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GetRaw() any // *gif.GIF or *WEBP.
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GetLoopCount() int // Number of times to loop the animation. 0 means infinite.
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ImageFrames
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}
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// ImageFrames provides access to the frames of an animated image.
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type ImageFrames interface {
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GetFrames() []image.Image
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// Frame durations in milliseconds.
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// Note that Gif frame durations are in 100ths of a second,
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// so they need to be multiplied by 10 to get milliseconds and vice versa.
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GetFrameDurations() []int
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SetFrames(frames []image.Image)
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SetWidthHeight(width, height int)
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}
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// ImageConfigProvider provides access to the image.Config of an image.
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type ImageConfigProvider interface {
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GetImageConfig() image.Config
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}
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// ColorPropertiesProvider provides access to CICP color properties (for HDR images).
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// Images implementing this interface preserve color space information through processing.
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type ColorPropertiesProvider interface {
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GetColorPrimaries() int
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GetTransferCharacteristics() int
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GetMatrixCoefficients() int
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}
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// HasColorProperties returns true if the image has non-zero color properties that should be preserved.
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func HasColorProperties(img image.Image) bool {
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if cpp, ok := img.(ColorPropertiesProvider); ok {
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// Consider it as having properties if any value is non-zero.
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return cpp.GetColorPrimaries() > 0 || cpp.GetTransferCharacteristics() > 0 || cpp.GetMatrixCoefficients() > 0
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}
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return false
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}
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// FrameDurationsToGifDelays converts frame durations in milliseconds to
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// GIF delays in 100ths of a second.
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func FrameDurationsToGifDelays(frameDurations []int) []int {
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delays := make([]int, len(frameDurations))
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for i, fd := range frameDurations {
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delays[i] = fd / 10
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if delays[i] == 0 && fd > 0 {
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delays[i] = 1
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}
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}
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return delays
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}
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// GifDelaysToFrameDurations converts GIF delays in 100ths of a second to
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// frame durations in milliseconds.
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func GifDelaysToFrameDurations(delays []int) []int {
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frameDurations := make([]int, len(delays))
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for i, d := range delays {
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frameDurations[i] = d * 10
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}
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return frameDurations
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}
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