feat: Add Session to expose decoding steps

.markdownlint.json

@@ -0,0 +1,6 @@
+{
+    "default": true,
+    "MD024": {
+        "siblings_only": true
+    }
+}

jpegxl-rs/CHANGELOG.md

@@ -1,49 +1,49 @@
-# Changelog
-
-## [Unreleased]
-
-## [0.11.1+libjxl-0.11.0](https://github.com/inflation/jpegxl-rs/compare/jpegxl-rs-v0.11.0+libjxl-0.11.0...jpegxl-rs-v0.11.1+libjxl-0.11.0) - 2024-10-01
-
-### 🐛 Bug Fixes
-
-- Fix doc gen
-
-### 📚 Documentation
-
-- Remove docsrs-specific reference to deleted "threads" feature
-
-## [0.11.0+libjxl-0.11.0](https://github.com/inflation/jpegxl-rs/compare/jpegxl-rs-v0.10.4+libjxl-0.10.3...jpegxl-rs-v0.11.0+libjxl-0.11.0) - 2024-09-27
-
-### ⛰️ Features
-
-- Update JPEG quality setting in encoder ([#74](https://github.com/inflation/jpegxl-rs/pull/74))
-
-### 🐛 Bug Fixes
-
-- Update release configuration for jpegxl-rs and jpegxl-sys packages
-- Change ffi function types to use `c-unwind` ABI
-- Change `JxlBoxType` to use system char type
-
-### 🚜 Refactor
-
-- Move `libjxl` functions into modules
-- Remove threads feature and update dependencies.
-- Don't use `-sys` in `-rs` with default features enabled
-
-### 📚 Documentation
-
-- Convert `libjxl` doc to rustdoc format with help from @copilot
-- Remove unnecessary feature attribute in thread pool implementations
-- Update how docs are generated ([#73](https://github.com/inflation/jpegxl-rs/pull/73))
-
-### 📦 Dependencies
-
-- Bump thiserror from 1.0.61 to 1.0.64
-- Bump pretty_assertions from 1.4.0 to 1.4.1
-- Bump derive_builder from 0.20.0 to 0.20.1
-- Bump testresult from 0.4.0 to 0.4.1
-- Bump image from 0.25.1 to 0.25.2
-
-### ⚙️ Miscellaneous Tasks
-
-- Update release-plz workflow and config
+# Changelog
+
+## [Unreleased]
+
+## [0.11.1+libjxl-0.11.0](https://github.com/inflation/jpegxl-rs/compare/jpegxl-rs-v0.11.0+libjxl-0.11.0...jpegxl-rs-v0.11.1+libjxl-0.11.0) - 2024-10-01
+
+### 🐛 Bug Fixes
+
+- Fix doc gen
+
+### 📚 Documentation
+
+- Remove docsrs-specific reference to deleted "threads" feature
+
+## [0.11.0+libjxl-0.11.0](https://github.com/inflation/jpegxl-rs/compare/jpegxl-rs-v0.10.4+libjxl-0.10.3...jpegxl-rs-v0.11.0+libjxl-0.11.0) - 2024-09-27
+
+### ⛰️ Features
+
+- Update JPEG quality setting in encoder ([#74](https://github.com/inflation/jpegxl-rs/pull/74))
+
+### 🐛 Bug Fixes
+
+- Update release configuration for jpegxl-rs and jpegxl-sys packages
+- Change ffi function types to use `c-unwind` ABI
+- Change `JxlBoxType` to use system char type
+
+### 🚜 Refactor
+
+- Move `libjxl` functions into modules
+- Remove threads feature and update dependencies.
+- Don't use `-sys` in `-rs` with default features enabled
+
+### 📚 Documentation
+
+- Convert `libjxl` doc to rustdoc format with help from @copilot
+- Remove unnecessary feature attribute in thread pool implementations
+- Update how docs are generated ([#73](https://github.com/inflation/jpegxl-rs/pull/73))
+
+### 📦 Dependencies
+
+- Bump thiserror from 1.0.61 to 1.0.64
+- Bump pretty_assertions from 1.4.0 to 1.4.1
+- Bump derive_builder from 0.20.0 to 0.20.1
+- Bump testresult from 0.4.0 to 0.4.1
+- Bump image from 0.25.1 to 0.25.2
+
+### ⚙️ Miscellaneous Tasks
+
+- Update release-plz workflow and config

jpegxl-rs/Cargo.toml

@@ -1,71 +1,71 @@
-[package]
-authors = ["Inflation <[email protected]>"]
-categories = ["api-bindings", "encoding", "multimedia::images"]
-description = "Safe Rust wrapper for JPEG XL reference implementation"
-edition = "2021"
-keywords = ["jpeg-xl", "jxl"]
-license = "GPL-3.0-or-later"
-name = "jpegxl-rs"
-readme = "README.md"
-repository = "https://github.com/inflation/jpegxl-rs"
-version = "0.11.1+libjxl-0.11.0"
-rust-version.workspace = true
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[lints.rust]
-missing_docs = "warn"
-unexpected_cfgs = { level = "warn", check-cfg = ['cfg(coverage_nightly)'] }
-
-[lints.clippy]
-pedantic = "warn"
-
-[features]
-default = ["image"]
-image = ["dep:image"]
-vendored = ["jpegxl-sys/vendored"]
-docs = ["jpegxl-sys/docs"]
-bench = []
-
-[dependencies]
-derive_builder = "0.20.1"
-image = { version = "0.25.2", optional = true, default-features = false }
-thiserror = "1.0.64"
-half = "2.4.1"
-byteorder = "1.5.0"
-
-[dependencies.jpegxl-sys]
-version = "0.11.1"
-path = "../jpegxl-sys"
-default-features = false
-
-[dev-dependencies]
-image = { version = "0.25.2", default-features = false, features = [
-    "jpeg",
-    "png",
-] }
-lcms2 = "6.1.0"
-pretty_assertions = "1.4.1"
-testresult = "0.4.1"
-
-[target.'cfg(not(target_family = "wasm"))'.dev-dependencies]
-criterion = "0.5.1"
-
-
-[package.metadata.docs.rs]
-rustdoc-args = ["--cfg", "docsrs"]
-features = ["docs"]
-
-[lib]
-bench = false
-path = "src/lib.rs"
-
-[[bench]]
-harness = false
-name = "decode"
-required-features = ["bench"]
-
-[[bench]]
-harness = false
-name = "encode"
-required-features = ["bench"]
+[package]
+authors = ["Inflation <[email protected]>"]
+categories = ["api-bindings", "encoding", "multimedia::images"]
+description = "Safe Rust wrapper for JPEG XL reference implementation"
+edition = "2021"
+keywords = ["jpeg-xl", "jxl"]
+license = "GPL-3.0-or-later"
+name = "jpegxl-rs"
+readme = "README.md"
+repository = "https://github.com/inflation/jpegxl-rs"
+version = "0.11.1+libjxl-0.11.0"
+rust-version.workspace = true
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lints.rust]
+missing_docs = "warn"
+unexpected_cfgs = { level = "warn", check-cfg = ['cfg(coverage_nightly)'] }
+
+[lints.clippy]
+pedantic = "warn"
+
+[features]
+default = ["image"]
+image = ["dep:image"]
+vendored = ["jpegxl-sys/vendored"]
+docs = ["jpegxl-sys/docs"]
+bench = []
+
+[dependencies]
+derive_builder = "0.20.1"
+image = { version = "0.25.2", optional = true, default-features = false }
+thiserror = "1.0.64"
+half = "2.4.1"
+byteorder = "1.5.0"
+
+[dependencies.jpegxl-sys]
+version = "0.11.1"
+path = "../jpegxl-sys"
+default-features = false
+
+[dev-dependencies]
+image = { version = "0.25.2", default-features = false, features = [
+    "jpeg",
+    "png",
+] }
+lcms2 = "6.1.0"
+pretty_assertions = "1.4.1"
+testresult = "0.4.1"
+
+[target.'cfg(not(target_family = "wasm"))'.dev-dependencies]
+criterion = "0.5.1"
+
+
+[package.metadata.docs.rs]
+rustdoc-args = ["--cfg", "docsrs"]
+features = ["docs"]
+
+[lib]
+bench = false
+path = "src/lib.rs"
+
+[[bench]]
+harness = false
+name = "decode"
+required-features = ["bench"]
+
+[[bench]]
+harness = false
+name = "encode"
+required-features = ["bench"]

jpegxl-rs/src/decode.rs

@@ -34,8 +34,12 @@ use crate::{
     utils::check_valid_signature,
 };
 
+mod event;
+pub use event::*;
 mod result;
 pub use result::*;
+mod session;
+pub use session::*;
 
 /// Basic information
 pub type BasicInfo = JxlBasicInfo;
@@ -414,6 +418,24 @@ impl<'pr, 'mm> JxlDecoder<'pr, 'mm> {
         Ok(())
     }
 
+    /// Start a new decoding session.
+    ///
+    /// Later event will overwrite the previous one if they are the same.
+    ///
+    /// # Arguments
+    ///
+    /// * `events` - The events to subscribe to during the session.
+    ///
+    /// # Errors
+    ///
+    /// Returns a [`DecodeError`] if the decoding session encounters an error.
+    pub fn session<I>(&mut self, events: I) -> Result<Session<'_, 'pr, 'mm>, DecodeError>
+    where
+        I: IntoIterator<Item = Event>,
+    {
+        Session::new(self, events)
+    }
+
     /// Decode a JPEG XL image
     ///
     /// # Errors

jpegxl-rs/src/decode/event.rs

@@ -0,0 +1,55 @@
+use std::ffi::c_int;
+
+use jpegxl_sys::common::types::JxlPixelFormat;
+/// Target of the color profile.
+pub use jpegxl_sys::decode::JxlColorProfileTarget as ColorProfileTarget;
+
+use super::{ColorEncodingConfig, Config};
+
+/// Events that can be subscribed to.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Event {
+    /// Basic information.
+    BasicInfo,
+    /// Color encoding.
+    ColorEncoding(ColorEncodingConfig),
+    /// Preview image.
+    PreviewImage {
+        /// Pixel format.
+        pixel_format: JxlPixelFormat,
+    },
+    /// JPEG reconstruction.
+    JpegReconstruction {
+        /// Initial buffer size. Increase it to reduce the number of reallocations.
+        init_buffer_size: usize,
+    },
+}
+
+impl From<Event> for c_int {
+    fn from(value: Event) -> Self {
+        match value {
+            Event::BasicInfo => 0x40,
+            Event::ColorEncoding(_) => 0x100,
+            Event::PreviewImage { .. } => 0x200,
+            Event::JpegReconstruction { .. } => 0x2000,
+        }
+    }
+}
+
+pub(crate) fn parse_events<I>(iter: I) -> (c_int, Config)
+where
+    I: IntoIterator<Item = Event>,
+{
+    iter.into_iter()
+        .fold((0, Config::default()), |(flag, mut config), x| {
+            let flag = flag | c_int::from(x);
+            let config = match x {
+                Event::ColorEncoding(val) => {
+                    config.color_profile = Some(val);
+                    config
+                }
+                _ => config,
+            };
+            (flag, config)
+        })
+}