xberg_libheif/integration/
image.rs

1use std::error::Error;
2use std::io::{Seek, SeekFrom};
3
4use image::error::{DecodingError, ImageFormatHint};
5use image::hooks::GenericReader;
6use image::{ColorType, ImageError, ImageResult};
7
8use crate::{ColorSpace, HeifContext, HeifError, ImageHandle, LibHeif, RgbChroma, StreamReader};
9
10macro_rules! magick {
11    ($v1:literal, $v2:literal, $v3:literal, $v4:literal) => {
12        [
13            &[0, 0, 0, 0, b'f', b't', b'y', b'p', $v1, $v2, $v3, $v4, 0, 0, 0, 0],
14            &[0, 0, 0, 0, b'f', b't', b'y', b'p', 0, 0, 0, 0, $v1, $v2, $v3, $v4],
15        ]
16    };
17}
18
19static MASKS: [&[u8]; 2] = [
20    &[0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0, 0, 0],
21    &[0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff],
22];
23
24/// HEVC image (`heic`) brand.
25///
26/// Image conforms to HEVC (H.265) Main or Main Still profile.
27static HEIC_BRAND: [&[u8]; 2] = magick!(b'h', b'e', b'i', b'c');
28/// HEVC image (`heix`) brand.
29///
30/// Image conforms to HEVC (H.265) Main 10 profile.
31static HEIX_BRAND: [&[u8]; 2] = magick!(b'h', b'e', b'i', b'x');
32/// AV1 image (`avif`) brand.
33static AVIF_BRAND: [&[u8]; 2] = magick!(b'a', b'v', b'i', b'f');
34/// JPEG image sequence (`jpgs`) brand.
35static JPGS_BRAND: [&[u8]; 2] = magick!(b'j', b'p', b'g', b's');
36/// JPEG 2000 image (`j2ki`) brand.
37static J2KI_BRAND: [&[u8]; 2] = magick!(b'j', b'2', b'k', b'i');
38/// HEIF image structural brand (`mif1`).
39///
40/// This does not imply a specific coding algorithm.
41static MIF1_BRAND: [&[u8]; 2] = magick!(b'm', b'i', b'f', b'1');
42/// HEIF image structural brand (`mif2`).
43///
44/// This does not imply a specific coding algorithm. `mif2` extends
45/// the requirements of `mif1` to include the `rref` and `iscl` item
46/// properties.
47static MIF2_BRAND: [&[u8]; 2] = magick!(b'm', b'i', b'f', b'2');
48
49/// Registers the decoder with the `image` crate for heif-files.
50pub fn register_heif_decoding_hook() -> bool {
51    let registered =
52        image::hooks::register_decoding_hook("heif".into(), Box::new(|r| Ok(Box::new(HeifDecoder::new(r)?))));
53    if registered {
54        for brands in [MIF1_BRAND, MIF2_BRAND, JPGS_BRAND, J2KI_BRAND] {
55            image::hooks::register_format_detection_hook("heif".into(), brands[0], Some(MASKS[0]));
56            image::hooks::register_format_detection_hook("heif".into(), brands[1], Some(MASKS[1]));
57        }
58    }
59    registered
60}
61
62/// Registers the decoder with the `image` crate for heic-files.
63pub fn register_heic_decoding_hook() -> bool {
64    let registered =
65        image::hooks::register_decoding_hook("heic".into(), Box::new(|r| Ok(Box::new(HeifDecoder::new(r)?))));
66    if registered {
67        for brands in [HEIC_BRAND, HEIX_BRAND] {
68            image::hooks::register_format_detection_hook("heic".into(), brands[0], Some(MASKS[0]));
69            image::hooks::register_format_detection_hook("heic".into(), brands[1], Some(MASKS[1]));
70        }
71    }
72    registered
73}
74
75/// Registers the decoder with the `image` crate for avif-files.
76pub fn register_avif_decoding_hook() -> bool {
77    let registered =
78        image::hooks::register_decoding_hook("avif".into(), Box::new(|r| Ok(Box::new(HeifDecoder::new(r)?))));
79    if registered {
80        image::hooks::register_format_detection_hook("avif".into(), AVIF_BRAND[0], Some(MASKS[0]));
81        image::hooks::register_format_detection_hook("avif".into(), AVIF_BRAND[1], Some(MASKS[1]));
82    }
83    registered
84}
85
86/// Registers the decoder with the `image` crate for all file types
87/// supported by the crate.
88pub fn register_all_decoding_hooks() {
89    register_heif_decoding_hook();
90    register_heic_decoding_hook();
91    register_avif_decoding_hook();
92}
93
94fn image_error(err: impl Into<Box<dyn Error + Send + Sync>>) -> ImageError {
95    ImageError::Decoding(DecodingError::new(ImageFormatHint::Name("heif".into()), err))
96}
97
98impl From<HeifError> for ImageError {
99    fn from(e: HeifError) -> Self {
100        image_error(e)
101    }
102}
103
104struct HeifDecoder<'a> {
105    _context: HeifContext<'a>,
106    image_handle: ImageHandle,
107    color_type: ColorType,
108}
109
110impl<'a> HeifDecoder<'a> {
111    fn new(mut reader: GenericReader<'a>) -> ImageResult<HeifDecoder<'a>> {
112        reader.seek(SeekFrom::End(0))?;
113        let total_size = reader.stream_position()?;
114        reader.seek(SeekFrom::Start(0))?;
115        let stream_reader = StreamReader::new(reader, total_size);
116        let context = HeifContext::read_from_reader(Box::new(stream_reader))?;
117        let image_handle = context.primary_image_handle()?;
118        let color_type = get_color_type(&image_handle)?;
119
120        Ok(Self {
121            _context: context,
122            image_handle,
123            color_type,
124        })
125    }
126}
127
128fn get_color_type(image_handle: &ImageHandle) -> ImageResult<ColorType> {
129    let has_alpha = image_handle.has_alpha_channel();
130    let color_space = image_handle.preferred_decoding_colorspace()?;
131    let (is_monochrome, is_hdr) = match color_space {
132        ColorSpace::YCbCr(_) => {
133            let bit_depth = image_handle.luma_bits_per_pixel();
134            (false, bit_depth > 8)
135        }
136        ColorSpace::Rgb(chroma) => match chroma {
137            RgbChroma::C444 | RgbChroma::Rgb | RgbChroma::Rgba => (false, false),
138            RgbChroma::HdrRgbBe | RgbChroma::HdrRgbaBe | RgbChroma::HdrRgbLe | RgbChroma::HdrRgbaLe => (false, true),
139        },
140        ColorSpace::Monochrome => {
141            let bit_depth = image_handle.luma_bits_per_pixel();
142            (true, bit_depth > 8)
143        }
144        ColorSpace::Undefined => {
145            let bit_depth = image_handle.luma_bits_per_pixel();
146            (false, bit_depth > 8)
147        }
148        #[cfg(feature = "v1_19")]
149        ColorSpace::NonVisual => {
150            return Err(image_error("Container doesn't have image data."));
151        }
152    };
153    let color_type = match (is_monochrome, has_alpha, is_hdr) {
154        (false, false, false) => ColorType::Rgb8,
155        (false, false, true) => ColorType::Rgb16,
156        (false, true, false) => ColorType::Rgba8,
157        (false, true, true) => ColorType::Rgba16,
158        (true, false, false) => ColorType::L8,
159        (true, false, true) => ColorType::L16,
160        (true, true, false) => ColorType::La8,
161        (true, true, true) => ColorType::La16,
162    };
163    Ok(color_type)
164}
165
166fn get_color_space(color_type: ColorType) -> ColorSpace {
167    let is_target_little_endian = u16::from_ne_bytes([1, 0]) == 1;
168    match color_type {
169        ColorType::L8 | ColorType::La8 | ColorType::L16 | ColorType::La16 => ColorSpace::Monochrome,
170        ColorType::Rgb8 => ColorSpace::Rgb(RgbChroma::Rgb),
171        ColorType::Rgba8 => ColorSpace::Rgb(RgbChroma::Rgba),
172        ColorType::Rgb16 => {
173            if is_target_little_endian {
174                ColorSpace::Rgb(RgbChroma::HdrRgbLe)
175            } else {
176                ColorSpace::Rgb(RgbChroma::HdrRgbBe)
177            }
178        }
179        ColorType::Rgba16 => {
180            if is_target_little_endian {
181                ColorSpace::Rgb(RgbChroma::HdrRgbaLe)
182            } else {
183                ColorSpace::Rgb(RgbChroma::HdrRgbaBe)
184            }
185        }
186        _ => ColorSpace::Rgb(RgbChroma::Rgb),
187    }
188}
189
190impl<'a> image::ImageDecoder for HeifDecoder<'a> {
191    fn dimensions(&self) -> (u32, u32) {
192        (self.image_handle.width(), self.image_handle.height())
193    }
194
195    fn color_type(&self) -> ColorType {
196        self.color_type
197    }
198
199    fn read_image(self, buf: &mut [u8]) -> ImageResult<()>
200    where
201        Self: Sized,
202    {
203        let color_space = get_color_space(self.color_type);
204        let img = LibHeif::new().decode(&self.image_handle, color_space, None)?;
205        if !matches!(img.color_space(), Some(c) if c == color_space) {
206            return Err(image_error("Color space mismatch."));
207        }
208        let planes = img.planes();
209        let Some(plane) = planes.interleaved else {
210            return Err(image_error("Image is not interleaved."));
211        };
212
213        let row_size = plane.width as usize * (plane.storage_bits_per_pixel / 8) as usize;
214        if row_size > plane.stride {
215            return Err(image_error("Row size is greater than stride."));
216        }
217        let dst_rows = buf.chunks_exact_mut(row_size);
218        let src_rows = plane
219            .data
220            .chunks_exact(plane.stride)
221            .take(plane.height as usize)
222            .map(|row| &row[..row_size]);
223        for (dst_row, src_row) in dst_rows.zip(src_rows) {
224            dst_row.copy_from_slice(src_row);
225        }
226        Ok(())
227    }
228
229    fn read_image_boxed(self: Box<Self>, buf: &mut [u8]) -> ImageResult<()> {
230        (*self).read_image(buf)
231    }
232}
xberg_libheif/integration/image.rs

xberg_libheif/integration/
image.rs
