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-rw-r--r--vendor/jpeg-decoder/src/idct.rs657
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diff --git a/vendor/jpeg-decoder/src/idct.rs b/vendor/jpeg-decoder/src/idct.rs
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+// Malicious JPEG files can cause operations in the idct to overflow.
+// One example is tests/crashtest/images/imagetestsuite/b0b8914cc5f7a6eff409f16d8cc236c5.jpg
+// That's why wrapping operators are needed.
+
+// Note: we have many values that are straight from a reference.
+// Do not warn on them or try to automatically change them.
+#![allow(clippy::excessive_precision)]
+// Note: consistency for unrolled, scaled offset loops
+#![allow(clippy::erasing_op)]
+#![allow(clippy::identity_op)]
+use crate::parser::Dimensions;
+use core::{convert::TryFrom, num::Wrapping};
+
+pub(crate) fn choose_idct_size(full_size: Dimensions, requested_size: Dimensions) -> usize {
+ fn scaled(len: u16, scale: usize) -> u16 {
+ ((len as u32 * scale as u32 - 1) / 8 + 1) as u16
+ }
+
+ for &scale in &[1, 2, 4] {
+ if scaled(full_size.width, scale) >= requested_size.width
+ || scaled(full_size.height, scale) >= requested_size.height
+ {
+ return scale;
+ }
+ }
+
+ 8
+}
+
+#[test]
+fn test_choose_idct_size() {
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 200,
+ height: 200
+ }
+ ),
+ 1
+ );
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 500,
+ height: 500
+ }
+ ),
+ 1
+ );
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 684,
+ height: 456
+ }
+ ),
+ 1
+ );
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 999,
+ height: 456
+ }
+ ),
+ 1
+ );
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 684,
+ height: 999
+ }
+ ),
+ 1
+ );
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 500,
+ height: 333
+ },
+ Dimensions {
+ width: 63,
+ height: 42
+ }
+ ),
+ 1
+ );
+
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 685,
+ height: 999
+ }
+ ),
+ 2
+ );
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 1000,
+ height: 1000
+ }
+ ),
+ 2
+ );
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 1400,
+ height: 1400
+ }
+ ),
+ 4
+ );
+
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 5472,
+ height: 3648
+ }
+ ),
+ 8
+ );
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 16384,
+ height: 16384
+ }
+ ),
+ 8
+ );
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 1,
+ height: 1
+ },
+ Dimensions {
+ width: 65535,
+ height: 65535
+ }
+ ),
+ 8
+ );
+ assert_eq!(
+ choose_idct_size(
+ Dimensions {
+ width: 5472,
+ height: 3648
+ },
+ Dimensions {
+ width: 16384,
+ height: 16384
+ }
+ ),
+ 8
+ );
+}
+
+pub(crate) fn dequantize_and_idct_block(
+ scale: usize,
+ coefficients: &[i16; 64],
+ quantization_table: &[u16; 64],
+ output_linestride: usize,
+ output: &mut [u8],
+) {
+ match scale {
+ 8 => dequantize_and_idct_block_8x8(
+ coefficients,
+ quantization_table,
+ output_linestride,
+ output,
+ ),
+ 4 => dequantize_and_idct_block_4x4(
+ coefficients,
+ quantization_table,
+ output_linestride,
+ output,
+ ),
+ 2 => dequantize_and_idct_block_2x2(
+ coefficients,
+ quantization_table,
+ output_linestride,
+ output,
+ ),
+ 1 => dequantize_and_idct_block_1x1(
+ coefficients,
+ quantization_table,
+ output_linestride,
+ output,
+ ),
+ _ => panic!("Unsupported IDCT scale {}/8", scale),
+ }
+}
+
+pub fn dequantize_and_idct_block_8x8(
+ coefficients: &[i16; 64],
+ quantization_table: &[u16; 64],
+ output_linestride: usize,
+ output: &mut [u8],
+) {
+ #[cfg(not(feature = "platform_independent"))]
+ if let Some(idct) = crate::arch::get_dequantize_and_idct_block_8x8() {
+ #[allow(unsafe_code)]
+ unsafe {
+ return idct(coefficients, quantization_table, output_linestride, output);
+ }
+ }
+
+ let output = output.chunks_mut(output_linestride);
+ dequantize_and_idct_block_8x8_inner(coefficients, quantization_table, output)
+}
+
+// This is based on stb_image's 'stbi__idct_block'.
+fn dequantize_and_idct_block_8x8_inner<'a, I>(
+ coefficients: &[i16; 64],
+ quantization_table: &[u16; 64],
+ output: I,
+) where
+ I: IntoIterator<Item = &'a mut [u8]>,
+ I::IntoIter: ExactSizeIterator<Item = &'a mut [u8]>,
+{
+ let output = output.into_iter();
+ debug_assert!(
+ output.len() >= 8,
+ "Output iterator has the wrong length: {}",
+ output.len()
+ );
+
+ let mut temp = [Wrapping(0); 64];
+
+ // columns
+ for i in 0..8 {
+ if coefficients[i + 8] == 0
+ && coefficients[i + 16] == 0
+ && coefficients[i + 24] == 0
+ && coefficients[i + 32] == 0
+ && coefficients[i + 40] == 0
+ && coefficients[i + 48] == 0
+ && coefficients[i + 56] == 0
+ {
+ let dcterm = dequantize(coefficients[i], quantization_table[i]) << 2;
+ temp[i] = dcterm;
+ temp[i + 8] = dcterm;
+ temp[i + 16] = dcterm;
+ temp[i + 24] = dcterm;
+ temp[i + 32] = dcterm;
+ temp[i + 40] = dcterm;
+ temp[i + 48] = dcterm;
+ temp[i + 56] = dcterm;
+ } else {
+ let s0 = dequantize(coefficients[i], quantization_table[i]);
+ let s1 = dequantize(coefficients[i + 8], quantization_table[i + 8]);
+ let s2 = dequantize(coefficients[i + 16], quantization_table[i + 16]);
+ let s3 = dequantize(coefficients[i + 24], quantization_table[i + 24]);
+ let s4 = dequantize(coefficients[i + 32], quantization_table[i + 32]);
+ let s5 = dequantize(coefficients[i + 40], quantization_table[i + 40]);
+ let s6 = dequantize(coefficients[i + 48], quantization_table[i + 48]);
+ let s7 = dequantize(coefficients[i + 56], quantization_table[i + 56]);
+
+ let Kernel {
+ xs: [x0, x1, x2, x3],
+ ts: [t0, t1, t2, t3],
+ } = kernel(
+ [s0, s1, s2, s3, s4, s5, s6, s7],
+ // constants scaled things up by 1<<12; let's bring them back
+ // down, but keep 2 extra bits of precision
+ 512,
+ );
+
+ temp[i] = (x0 + t3) >> 10;
+ temp[i + 56] = (x0 - t3) >> 10;
+ temp[i + 8] = (x1 + t2) >> 10;
+ temp[i + 48] = (x1 - t2) >> 10;
+ temp[i + 16] = (x2 + t1) >> 10;
+ temp[i + 40] = (x2 - t1) >> 10;
+ temp[i + 24] = (x3 + t0) >> 10;
+ temp[i + 32] = (x3 - t0) >> 10;
+ }
+ }
+
+ for (chunk, output_chunk) in temp.chunks_exact(8).zip(output) {
+ let chunk = <&[_; 8]>::try_from(chunk).unwrap();
+
+ // constants scaled things up by 1<<12, plus we had 1<<2 from first
+ // loop, plus horizontal and vertical each scale by sqrt(8) so together
+ // we've got an extra 1<<3, so 1<<17 total we need to remove.
+ // so we want to round that, which means adding 0.5 * 1<<17,
+ // aka 65536. Also, we'll end up with -128 to 127 that we want
+ // to encode as 0..255 by adding 128, so we'll add that before the shift
+ const X_SCALE: i32 = 65536 + (128 << 17);
+
+ // eliminate downstream bounds checks
+ let output_chunk = &mut output_chunk[..8];
+
+ // TODO When the minimum rust version supports it
+ // let [s0, rest @ ..] = chunk;
+ let (s0, rest) = chunk.split_first().unwrap();
+ if *rest == [Wrapping(0); 7] {
+ let dcterm = stbi_clamp((stbi_fsh(*s0) + Wrapping(X_SCALE)) >> 17);
+ output_chunk[0] = dcterm;
+ output_chunk[1] = dcterm;
+ output_chunk[2] = dcterm;
+ output_chunk[3] = dcterm;
+ output_chunk[4] = dcterm;
+ output_chunk[5] = dcterm;
+ output_chunk[6] = dcterm;
+ output_chunk[7] = dcterm;
+ } else {
+ let Kernel {
+ xs: [x0, x1, x2, x3],
+ ts: [t0, t1, t2, t3],
+ } = kernel(*chunk, X_SCALE);
+
+ output_chunk[0] = stbi_clamp((x0 + t3) >> 17);
+ output_chunk[7] = stbi_clamp((x0 - t3) >> 17);
+ output_chunk[1] = stbi_clamp((x1 + t2) >> 17);
+ output_chunk[6] = stbi_clamp((x1 - t2) >> 17);
+ output_chunk[2] = stbi_clamp((x2 + t1) >> 17);
+ output_chunk[5] = stbi_clamp((x2 - t1) >> 17);
+ output_chunk[3] = stbi_clamp((x3 + t0) >> 17);
+ output_chunk[4] = stbi_clamp((x3 - t0) >> 17);
+ }
+ }
+}
+
+struct Kernel {
+ xs: [Wrapping<i32>; 4],
+ ts: [Wrapping<i32>; 4],
+}
+
+#[inline]
+fn kernel_x([s0, s2, s4, s6]: [Wrapping<i32>; 4], x_scale: i32) -> [Wrapping<i32>; 4] {
+ // Even `chunk` indicies
+ let (t2, t3);
+ {
+ let p2 = s2;
+ let p3 = s6;
+
+ let p1 = (p2 + p3) * stbi_f2f(0.5411961);
+ t2 = p1 + p3 * stbi_f2f(-1.847759065);
+ t3 = p1 + p2 * stbi_f2f(0.765366865);
+ }
+
+ let (t0, t1);
+ {
+ let p2 = s0;
+ let p3 = s4;
+
+ t0 = stbi_fsh(p2 + p3);
+ t1 = stbi_fsh(p2 - p3);
+ }
+
+ let x0 = t0 + t3;
+ let x3 = t0 - t3;
+ let x1 = t1 + t2;
+ let x2 = t1 - t2;
+
+ let x_scale = Wrapping(x_scale);
+
+ [x0 + x_scale, x1 + x_scale, x2 + x_scale, x3 + x_scale]
+}
+
+#[inline]
+fn kernel_t([s1, s3, s5, s7]: [Wrapping<i32>; 4]) -> [Wrapping<i32>; 4] {
+ // Odd `chunk` indicies
+ let mut t0 = s7;
+ let mut t1 = s5;
+ let mut t2 = s3;
+ let mut t3 = s1;
+
+ let p3 = t0 + t2;
+ let p4 = t1 + t3;
+ let p1 = t0 + t3;
+ let p2 = t1 + t2;
+ let p5 = (p3 + p4) * stbi_f2f(1.175875602);
+
+ t0 *= stbi_f2f(0.298631336);
+ t1 *= stbi_f2f(2.053119869);
+ t2 *= stbi_f2f(3.072711026);
+ t3 *= stbi_f2f(1.501321110);
+
+ let p1 = p5 + p1 * stbi_f2f(-0.899976223);
+ let p2 = p5 + p2 * stbi_f2f(-2.562915447);
+ let p3 = p3 * stbi_f2f(-1.961570560);
+ let p4 = p4 * stbi_f2f(-0.390180644);
+
+ t3 += p1 + p4;
+ t2 += p2 + p3;
+ t1 += p2 + p4;
+ t0 += p1 + p3;
+
+ [t0, t1, t2, t3]
+}
+
+#[inline]
+fn kernel([s0, s1, s2, s3, s4, s5, s6, s7]: [Wrapping<i32>; 8], x_scale: i32) -> Kernel {
+ Kernel {
+ xs: kernel_x([s0, s2, s4, s6], x_scale),
+ ts: kernel_t([s1, s3, s5, s7]),
+ }
+}
+
+#[inline(always)]
+fn dequantize(c: i16, q: u16) -> Wrapping<i32> {
+ Wrapping(i32::from(c) * i32::from(q))
+}
+
+// 4x4 and 2x2 IDCT based on Rakesh Dugad and Narendra Ahuja: "A Fast Scheme for Image Size Change in the Compressed Domain" (2001).
+// http://sylvana.net/jpegcrop/jidctred/
+fn dequantize_and_idct_block_4x4(
+ coefficients: &[i16; 64],
+ quantization_table: &[u16; 64],
+ output_linestride: usize,
+ output: &mut [u8],
+) {
+ debug_assert_eq!(coefficients.len(), 64);
+ let mut temp = [Wrapping(0i32); 4 * 4];
+
+ const CONST_BITS: usize = 12;
+ const PASS1_BITS: usize = 2;
+ const FINAL_BITS: usize = CONST_BITS + PASS1_BITS + 3;
+
+ // columns
+ for i in 0..4 {
+ let s0 = Wrapping(coefficients[i + 8 * 0] as i32 * quantization_table[i + 8 * 0] as i32);
+ let s1 = Wrapping(coefficients[i + 8 * 1] as i32 * quantization_table[i + 8 * 1] as i32);
+ let s2 = Wrapping(coefficients[i + 8 * 2] as i32 * quantization_table[i + 8 * 2] as i32);
+ let s3 = Wrapping(coefficients[i + 8 * 3] as i32 * quantization_table[i + 8 * 3] as i32);
+
+ let x0 = (s0 + s2) << PASS1_BITS;
+ let x2 = (s0 - s2) << PASS1_BITS;
+
+ let p1 = (s1 + s3) * stbi_f2f(0.541196100);
+ let t0 = (p1 + s3 * stbi_f2f(-1.847759065) + Wrapping(512)) >> (CONST_BITS - PASS1_BITS);
+ let t2 = (p1 + s1 * stbi_f2f(0.765366865) + Wrapping(512)) >> (CONST_BITS - PASS1_BITS);
+
+ temp[i + 4 * 0] = x0 + t2;
+ temp[i + 4 * 3] = x0 - t2;
+ temp[i + 4 * 1] = x2 + t0;
+ temp[i + 4 * 2] = x2 - t0;
+ }
+
+ for i in 0..4 {
+ let s0 = temp[i * 4 + 0];
+ let s1 = temp[i * 4 + 1];
+ let s2 = temp[i * 4 + 2];
+ let s3 = temp[i * 4 + 3];
+
+ let x0 = (s0 + s2) << CONST_BITS;
+ let x2 = (s0 - s2) << CONST_BITS;
+
+ let p1 = (s1 + s3) * stbi_f2f(0.541196100);
+ let t0 = p1 + s3 * stbi_f2f(-1.847759065);
+ let t2 = p1 + s1 * stbi_f2f(0.765366865);
+
+ // constants scaled things up by 1<<12, plus we had 1<<2 from first
+ // loop, plus horizontal and vertical each scale by sqrt(8) so together
+ // we've got an extra 1<<3, so 1<<17 total we need to remove.
+ // so we want to round that, which means adding 0.5 * 1<<17,
+ // aka 65536. Also, we'll end up with -128 to 127 that we want
+ // to encode as 0..255 by adding 128, so we'll add that before the shift
+ let x0 = x0 + Wrapping(1 << (FINAL_BITS - 1)) + Wrapping(128 << FINAL_BITS);
+ let x2 = x2 + Wrapping(1 << (FINAL_BITS - 1)) + Wrapping(128 << FINAL_BITS);
+
+ let output = &mut output[i * output_linestride..][..4];
+ output[0] = stbi_clamp((x0 + t2) >> FINAL_BITS);
+ output[3] = stbi_clamp((x0 - t2) >> FINAL_BITS);
+ output[1] = stbi_clamp((x2 + t0) >> FINAL_BITS);
+ output[2] = stbi_clamp((x2 - t0) >> FINAL_BITS);
+ }
+}
+
+fn dequantize_and_idct_block_2x2(
+ coefficients: &[i16; 64],
+ quantization_table: &[u16; 64],
+ output_linestride: usize,
+ output: &mut [u8],
+) {
+ debug_assert_eq!(coefficients.len(), 64);
+
+ const SCALE_BITS: usize = 3;
+
+ // Column 0
+ let s00 = Wrapping(coefficients[8 * 0] as i32 * quantization_table[8 * 0] as i32);
+ let s10 = Wrapping(coefficients[8 * 1] as i32 * quantization_table[8 * 1] as i32);
+
+ let x0 = s00 + s10;
+ let x2 = s00 - s10;
+
+ // Column 1
+ let s01 = Wrapping(coefficients[8 * 0 + 1] as i32 * quantization_table[8 * 0 + 1] as i32);
+ let s11 = Wrapping(coefficients[8 * 1 + 1] as i32 * quantization_table[8 * 1 + 1] as i32);
+
+ let x1 = s01 + s11;
+ let x3 = s01 - s11;
+
+ let x0 = x0 + Wrapping(1 << (SCALE_BITS - 1)) + Wrapping(128 << SCALE_BITS);
+ let x2 = x2 + Wrapping(1 << (SCALE_BITS - 1)) + Wrapping(128 << SCALE_BITS);
+
+ // Row 0
+ output[0] = stbi_clamp((x0 + x1) >> SCALE_BITS);
+ output[1] = stbi_clamp((x0 - x1) >> SCALE_BITS);
+
+ // Row 1
+ output[output_linestride + 0] = stbi_clamp((x2 + x3) >> SCALE_BITS);
+ output[output_linestride + 1] = stbi_clamp((x2 - x3) >> SCALE_BITS);
+}
+
+fn dequantize_and_idct_block_1x1(
+ coefficients: &[i16; 64],
+ quantization_table: &[u16; 64],
+ _output_linestride: usize,
+ output: &mut [u8],
+) {
+ debug_assert_eq!(coefficients.len(), 64);
+
+ let s0 = (Wrapping(coefficients[0] as i32 * quantization_table[0] as i32) + Wrapping(128 * 8)) / Wrapping(8);
+ output[0] = stbi_clamp(s0);
+}
+
+// take a -128..127 value and stbi__clamp it and convert to 0..255
+fn stbi_clamp(x: Wrapping<i32>) -> u8 {
+ x.0.max(0).min(255) as u8
+}
+
+fn stbi_f2f(x: f32) -> Wrapping<i32> {
+ Wrapping((x * 4096.0 + 0.5) as i32)
+}
+
+fn stbi_fsh(x: Wrapping<i32>) -> Wrapping<i32> {
+ x << 12
+}
+
+#[test]
+fn test_dequantize_and_idct_block_8x8() {
+ #[cfg_attr(rustfmt, rustfmt_skip)]
+ let coefficients: [i16; 8 * 8] = [
+ -14, -39, 58, -2, 3, 3, 0, 1,
+ 11, 27, 4, -3, 3, 0, 1, 0,
+ -6, -13, -9, -1, -2, -1, 0, 0,
+ -4, 0, -1, -2, 0, 0, 0, 0,
+ 3, 0, 0, 0, 0, 0, 0, 0,
+ -3, -2, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0
+ ];
+
+ #[cfg_attr(rustfmt, rustfmt_skip)]
+ let quantization_table: [u16; 8 * 8] = [
+ 8, 6, 5, 8, 12, 20, 26, 31,
+ 6, 6, 7, 10, 13, 29, 30, 28,
+ 7, 7, 8, 12, 20, 29, 35, 28,
+ 7, 9, 11, 15, 26, 44, 40, 31,
+ 9, 11, 19, 28, 34, 55, 52, 39,
+ 12, 18, 28, 32, 41, 52, 57, 46,
+ 25, 32, 39, 44, 52, 61, 60, 51,
+ 36, 46, 48, 49, 56, 50, 52, 50
+ ];
+ let output_linestride: usize = 8;
+ let mut output = [0u8; 8 * 8];
+ dequantize_and_idct_block_8x8(
+ &coefficients,
+ &quantization_table,
+ output_linestride,
+ &mut output,
+ );
+ #[cfg_attr(rustfmt, rustfmt_skip)]
+ let expected_output = [
+ 118, 92, 110, 83, 77, 93, 144, 198,
+ 172, 116, 114, 87, 78, 93, 146, 191,
+ 194, 107, 91, 76, 71, 93, 160, 198,
+ 196, 100, 80, 74, 67, 92, 174, 209,
+ 182, 104, 88, 81, 68, 89, 178, 206,
+ 105, 64, 59, 59, 63, 94, 183, 201,
+ 35, 27, 28, 37, 72, 121, 203, 204,
+ 37, 45, 41, 47, 98, 154, 223, 208
+ ];
+ for i in 0..64 {
+ assert!((output[i] as i16 - expected_output[i] as i16).abs() <= 1);
+ }
+}
+
+#[test]
+fn test_dequantize_and_idct_block_8x8_all_zero() {
+ let mut output = [0u8; 8 * 8];
+ dequantize_and_idct_block_8x8(&[0; 8 * 8], &[666; 8 * 8], 8, &mut output);
+ assert_eq!(&output[..], &[128; 8 * 8][..]);
+}
+
+#[test]
+fn test_dequantize_and_idct_block_8x8_saturated() {
+ // Arch-specific IDCT implementations need not handle i16::MAX values.
+ #[cfg(not(feature = "platform_independent"))]
+ if crate::arch::get_dequantize_and_idct_block_8x8().is_some() {
+ return;
+ }
+ let mut output = [0u8; 8 * 8];
+ dequantize_and_idct_block_8x8(&[i16::MAX; 8 * 8], &[u16::MAX; 8 * 8], 8, &mut output);
+ #[cfg_attr(rustfmt, rustfmt_skip)]
+ let expected = [
+ 0, 0, 0, 255, 255, 0, 0, 255,
+ 0, 0, 215, 0, 0, 255, 255, 0,
+ 255, 255, 255, 255, 255, 0, 0, 255,
+ 0, 0, 255, 0, 255, 0, 255, 255,
+ 0, 0, 255, 255, 0, 255, 0, 0,
+ 255, 255, 0, 255, 255, 255, 170, 0,
+ 0, 255, 0, 0, 0, 0, 0, 255,
+ 255, 255, 0, 255, 0, 255, 0, 0
+ ];
+ assert_eq!(&output[..], &expected[..]);
+}
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