libheif_rs/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            // As a major brand
14            &[
15                0, 0, 0, 0, b'f', b't', b'y', b'p', $v1, $v2, $v3, $v4, 0, 0, 0, 0,
16            ],
17            // As a minor brand
18            &[
19                0, 0, 0, 0, b'f', b't', b'y', b'p', 0, 0, 0, 0, $v1, $v2, $v3, $v4,
20            ],
21        ]
22    };
23}
24
25static MASKS: [&[u8]; 2] = [
26    &[
27        0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0, 0, 0,
28    ],
29    &[
30        0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff,
31    ],
32];
33
34/// HEVC image (`heic`) brand.
35///
36/// Image conforms to HEVC (H.265) Main or Main Still profile.
37static HEIC_BRAND: [&[u8]; 2] = magick!(b'h', b'e', b'i', b'c');
38/// HEVC image (`heix`) brand.
39///
40/// Image conforms to HEVC (H.265) Main 10 profile.
41static HEIX_BRAND: [&[u8]; 2] = magick!(b'h', b'e', b'i', b'x');
42/// AV1 image (`avif`) brand.
43static AVIF_BRAND: [&[u8]; 2] = magick!(b'a', b'v', b'i', b'f');
44/// JPEG image sequence (`jpgs`) brand.
45static JPGS_BRAND: [&[u8]; 2] = magick!(b'j', b'p', b'g', b's');
46/// JPEG 2000 image (`j2ki`) brand.
47static J2KI_BRAND: [&[u8]; 2] = magick!(b'j', b'2', b'k', b'i');
48/// HEIF image structural brand (`mif1`).
49///
50/// This does not imply a specific coding algorithm.
51static MIF1_BRAND: [&[u8]; 2] = magick!(b'm', b'i', b'f', b'1');
52/// HEIF image structural brand (`mif2`).
53///
54/// This does not imply a specific coding algorithm. `mif2` extends
55/// the requirements of `mif1` to include the `rref` and `iscl` item
56/// properties.
57static MIF2_BRAND: [&[u8]; 2] = magick!(b'm', b'i', b'f', b'2');
58
59/// Registers the decoder with the `image` crate for heif-files.
60pub fn register_heif_decoding_hook() -> bool {
61    let registered = image::hooks::register_decoding_hook(
62        "heif".into(),
63        Box::new(|r| Ok(Box::new(HeifDecoder::new(r)?))),
64    );
65    if registered {
66        for brands in [MIF1_BRAND, MIF2_BRAND, JPGS_BRAND, J2KI_BRAND] {
67            image::hooks::register_format_detection_hook("heif".into(), brands[0], Some(MASKS[0]));
68            image::hooks::register_format_detection_hook("heif".into(), brands[1], Some(MASKS[1]));
69        }
70    }
71    registered
72}
73
74/// Registers the decoder with the `image` crate for heic-files.
75pub fn register_heic_decoding_hook() -> bool {
76    let registered = image::hooks::register_decoding_hook(
77        "heic".into(),
78        Box::new(|r| Ok(Box::new(HeifDecoder::new(r)?))),
79    );
80    if registered {
81        for brands in [HEIC_BRAND, HEIX_BRAND] {
82            image::hooks::register_format_detection_hook("heic".into(), brands[0], Some(MASKS[0]));
83            image::hooks::register_format_detection_hook("heic".into(), brands[1], Some(MASKS[1]));
84        }
85    }
86    registered
87}
88
89/// Registers the decoder with the `image` crate for avif-files.
90pub fn register_avif_decoding_hook() -> bool {
91    let registered = image::hooks::register_decoding_hook(
92        "avif".into(),
93        Box::new(|r| Ok(Box::new(HeifDecoder::new(r)?))),
94    );
95    if registered {
96        image::hooks::register_format_detection_hook("avif".into(), AVIF_BRAND[0], Some(MASKS[0]));
97        image::hooks::register_format_detection_hook("avif".into(), AVIF_BRAND[1], Some(MASKS[1]));
98    }
99    registered
100}
101
102/// Registers the decoder with the `image` crate for all file types
103/// supported by the crate.
104pub fn register_all_decoding_hooks() {
105    register_heif_decoding_hook();
106    register_heic_decoding_hook();
107    register_avif_decoding_hook();
108}
109
110fn image_error(err: impl Into<Box<dyn Error + Send + Sync>>) -> ImageError {
111    ImageError::Decoding(DecodingError::new(
112        ImageFormatHint::Name("heif".into()),
113        err,
114    ))
115}
116
117impl From<HeifError> for ImageError {
118    fn from(e: HeifError) -> Self {
119        image_error(e)
120    }
121}
122
123struct HeifDecoder<'a> {
124    _context: HeifContext<'a>,
125    image_handle: ImageHandle,
126    color_type: ColorType,
127}
128
129impl<'a> HeifDecoder<'a> {
130    fn new(mut reader: GenericReader<'a>) -> ImageResult<HeifDecoder<'a>> {
131        reader.seek(SeekFrom::End(0))?;
132        let total_size = reader.stream_position()?;
133        reader.seek(SeekFrom::Start(0))?;
134        let stream_reader = StreamReader::new(reader, total_size);
135        let context = HeifContext::read_from_reader(Box::new(stream_reader))?;
136        let image_handle = context.primary_image_handle()?;
137        let color_type = get_color_type(&image_handle)?;
138
139        Ok(Self {
140            _context: context,
141            image_handle,
142            color_type,
143        })
144    }
145}
146
147fn get_color_type(image_handle: &ImageHandle) -> ImageResult<ColorType> {
148    let has_alpha = image_handle.has_alpha_channel();
149    let color_space = image_handle.preferred_decoding_colorspace()?;
150    let (is_monochrome, is_hdr) = match color_space {
151        ColorSpace::YCbCr(_) => {
152            let bit_depth = image_handle.luma_bits_per_pixel();
153            (false, bit_depth > 8)
154        }
155        ColorSpace::Rgb(chroma) => match chroma {
156            RgbChroma::C444 | RgbChroma::Rgb | RgbChroma::Rgba => (false, false),
157            RgbChroma::HdrRgbBe
158            | RgbChroma::HdrRgbaBe
159            | RgbChroma::HdrRgbLe
160            | RgbChroma::HdrRgbaLe => (false, true),
161        },
162        ColorSpace::Monochrome => {
163            let bit_depth = image_handle.luma_bits_per_pixel();
164            (true, bit_depth > 8)
165        }
166        ColorSpace::Undefined => {
167            let bit_depth = image_handle.luma_bits_per_pixel();
168            (false, bit_depth > 8)
169        }
170        #[cfg(feature = "v1_19")]
171        ColorSpace::NonVisual => {
172            return Err(image_error("Container doesn't have image data."));
173        }
174    };
175    let color_type = match (is_monochrome, has_alpha, is_hdr) {
176        (false, false, false) => ColorType::Rgb8,
177        (false, false, true) => ColorType::Rgb16,
178        (false, true, false) => ColorType::Rgba8,
179        (false, true, true) => ColorType::Rgba16,
180        (true, false, false) => ColorType::L8,
181        (true, false, true) => ColorType::L16,
182        (true, true, false) => ColorType::La8,
183        (true, true, true) => ColorType::La16,
184    };
185    Ok(color_type)
186}
187
188fn get_color_space(color_type: ColorType) -> ColorSpace {
189    let is_target_little_endian = u16::from_ne_bytes([1, 0]) == 1;
190    match color_type {
191        ColorType::L8 | ColorType::La8 | ColorType::L16 | ColorType::La16 => ColorSpace::Monochrome,
192        ColorType::Rgb8 => ColorSpace::Rgb(RgbChroma::Rgb),
193        ColorType::Rgba8 => ColorSpace::Rgb(RgbChroma::Rgba),
194        ColorType::Rgb16 => {
195            if is_target_little_endian {
196                ColorSpace::Rgb(RgbChroma::HdrRgbLe)
197            } else {
198                ColorSpace::Rgb(RgbChroma::HdrRgbBe)
199            }
200        }
201        ColorType::Rgba16 => {
202            if is_target_little_endian {
203                ColorSpace::Rgb(RgbChroma::HdrRgbaLe)
204            } else {
205                ColorSpace::Rgb(RgbChroma::HdrRgbaBe)
206            }
207        }
208        _ => ColorSpace::Rgb(RgbChroma::Rgb),
209    }
210}
211
212impl<'a> image::ImageDecoder for HeifDecoder<'a> {
213    fn dimensions(&self) -> (u32, u32) {
214        (self.image_handle.width(), self.image_handle.height())
215    }
216
217    fn color_type(&self) -> ColorType {
218        self.color_type
219    }
220
221    fn read_image(self, buf: &mut [u8]) -> ImageResult<()>
222    where
223        Self: Sized,
224    {
225        let color_space = get_color_space(self.color_type);
226        let img = LibHeif::new().decode(&self.image_handle, color_space, None)?;
227        if !matches!(img.color_space(), Some(c) if c == color_space) {
228            return Err(image_error("Color space mismatch."));
229        }
230        let planes = img.planes();
231        let Some(plane) = planes.interleaved else {
232            return Err(image_error("Image is not interleaved."));
233        };
234
235        let row_size = plane.width as usize * (plane.storage_bits_per_pixel / 8) as usize;
236        if row_size > plane.stride {
237            return Err(image_error("Row size is greater than stride."));
238        }
239        let dst_rows = buf.chunks_exact_mut(row_size);
240        let src_rows = plane
241            .data
242            .chunks_exact(plane.stride)
243            .take(plane.height as usize)
244            .map(|row| &row[..row_size]);
245        for (dst_row, src_row) in dst_rows.zip(src_rows) {
246            dst_row.copy_from_slice(src_row);
247        }
248        Ok(())
249    }
250
251    fn read_image_boxed(self: Box<Self>, buf: &mut [u8]) -> ImageResult<()> {
252        (*self).read_image(buf)
253    }
254}
libheif_rs/integration/image.rs

libheif_rs/integration/
image.rs
