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Diffstat (limited to 'vendor/jpeg-decoder/src/idct.rs')
| -rw-r--r-- | vendor/jpeg-decoder/src/idct.rs | 657 |
1 files changed, 0 insertions, 657 deletions
diff --git a/vendor/jpeg-decoder/src/idct.rs b/vendor/jpeg-decoder/src/idct.rs deleted file mode 100644 index ad8dc4c..0000000 --- a/vendor/jpeg-decoder/src/idct.rs +++ /dev/null @@ -1,657 +0,0 @@ -// 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[..]); -} |