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// Copyright (c) the JPEG XL Project Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
use crate::{
bit_reader::BitReader,
error::Error,
headers::encodings::{self, *},
};
use jxl_macros::UnconditionalCoder;
use num_derive::FromPrimitive;
#[derive(UnconditionalCoder, Copy, Clone, PartialEq, Debug, FromPrimitive, Default)]
enum AspectRatio {
#[default]
Unknown = 0,
Ratio1Over1 = 1,
Ratio12Over10 = 2,
Ratio4Over3 = 3,
Ratio3Over2 = 4,
Ratio16Over9 = 5,
Ratio5Over4 = 6,
Ratio2Over1 = 7,
}
#[derive(UnconditionalCoder, Debug, Clone, Default)]
#[validate]
pub struct Size {
small: bool,
#[condition(small)]
#[coder(Bits(5) + 1)]
ysize_div8: Option<u32>,
#[condition(!small)]
#[coder(1 + u2S(Bits(9), Bits(13), Bits(18), Bits(30)))]
ysize: Option<u32>,
#[coder(Bits(3))]
ratio: AspectRatio,
#[condition(small && ratio == AspectRatio::Unknown)]
#[coder(Bits(5) + 1)]
xsize_div8: Option<u32>,
#[condition(!small && ratio == AspectRatio::Unknown)]
#[coder(1 + u2S(Bits(9), Bits(13), Bits(18), Bits(30)))]
xsize: Option<u32>,
}
#[derive(UnconditionalCoder, Debug, Clone)]
#[validate]
pub struct Preview {
div8: bool,
#[condition(div8)]
#[coder(u2S(16, 32, Bits(5) + 1, Bits(9) + 33))]
ysize_div8: Option<u32>,
#[condition(!div8)]
#[coder(1 + u2S(Bits(6), Bits(8) + 64, Bits(10) + 320, Bits(12) + 1344))]
ysize: Option<u32>,
#[coder(Bits(3))]
ratio: AspectRatio,
#[condition(div8 && ratio == AspectRatio::Unknown)]
#[coder(u2S(16, 32, Bits(5) + 1, Bits(9) + 33))]
xsize_div8: Option<u32>,
#[condition(!div8 && ratio == AspectRatio::Unknown)]
#[coder(1 + u2S(Bits(6), Bits(8) + 64, Bits(10) + 320, Bits(12) + 1344))]
xsize: Option<u32>,
}
fn map_aspect_ratio<T: Fn() -> u64>(ysize: u32, ratio: AspectRatio, fallback: T) -> u64 {
match ratio {
AspectRatio::Unknown => fallback(),
AspectRatio::Ratio1Over1 => ysize as u64,
AspectRatio::Ratio12Over10 => ysize as u64 * 12 / 10,
AspectRatio::Ratio4Over3 => ysize as u64 * 4 / 3,
AspectRatio::Ratio3Over2 => ysize as u64 * 3 / 2,
AspectRatio::Ratio16Over9 => ysize as u64 * 16 / 9,
AspectRatio::Ratio5Over4 => ysize as u64 * 5 / 4,
AspectRatio::Ratio2Over1 => ysize as u64 * 2,
}
}
impl Size {
pub fn ysize(&self) -> u32 {
if self.small {
self.ysize_div8.unwrap() * 8
} else {
self.ysize.unwrap()
}
}
fn compute_xsize(&self) -> Result<u32, Error> {
let x = map_aspect_ratio(self.ysize(), self.ratio, /* fallback */ || {
if self.small {
self.xsize_div8.unwrap() as u64 * 8
} else {
self.xsize.unwrap() as u64
}
});
u32::try_from(x).map_err(|_| Error::ImageDimensionTooLarge(x))
}
fn check(&self, _: &encodings::Empty) -> Result<(), Error> {
self.compute_xsize()?;
Ok(())
}
pub fn xsize(&self) -> u32 {
// Validation happens during struct decoding via #[validate].
// If we reach here, compute_xsize() is guaranteed to succeed.
self.compute_xsize().unwrap()
}
}
impl Preview {
pub fn ysize(&self) -> u32 {
if self.div8 {
self.ysize_div8.unwrap() * 8
} else {
self.ysize.unwrap()
}
}
fn compute_xsize(&self) -> Result<u32, Error> {
let x = map_aspect_ratio(self.ysize(), self.ratio, /* fallback */ || {
if self.div8 {
self.xsize_div8.unwrap() as u64 * 8
} else {
self.xsize.unwrap() as u64
}
});
u32::try_from(x).map_err(|_| Error::ImageDimensionTooLarge(x))
}
fn check(&self, _: &encodings::Empty) -> Result<(), Error> {
self.compute_xsize()?;
Ok(())
}
pub fn xsize(&self) -> u32 {
// Validation happens during struct decoding via #[validate].
// If we reach here, compute_xsize() is guaranteed to succeed.
self.compute_xsize().unwrap()
}
}