| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/jpeg-decoder-0.1.22/src/parser.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>parser.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../jpeg_decoder/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../jpeg_decoder/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| <span id="523">523</span> |
| <span id="524">524</span> |
| <span id="525">525</span> |
| <span id="526">526</span> |
| <span id="527">527</span> |
| <span id="528">528</span> |
| <span id="529">529</span> |
| <span id="530">530</span> |
| <span id="531">531</span> |
| <span id="532">532</span> |
| <span id="533">533</span> |
| <span id="534">534</span> |
| <span id="535">535</span> |
| <span id="536">536</span> |
| <span id="537">537</span> |
| <span id="538">538</span> |
| <span id="539">539</span> |
| <span id="540">540</span> |
| <span id="541">541</span> |
| <span id="542">542</span> |
| <span id="543">543</span> |
| <span id="544">544</span> |
| <span id="545">545</span> |
| <span id="546">546</span> |
| <span id="547">547</span> |
| <span id="548">548</span> |
| <span id="549">549</span> |
| <span id="550">550</span> |
| <span id="551">551</span> |
| <span id="552">552</span> |
| <span id="553">553</span> |
| <span id="554">554</span> |
| <span id="555">555</span> |
| <span id="556">556</span> |
| <span id="557">557</span> |
| <span id="558">558</span> |
| <span id="559">559</span> |
| <span id="560">560</span> |
| <span id="561">561</span> |
| <span id="562">562</span> |
| <span id="563">563</span> |
| <span id="564">564</span> |
| <span id="565">565</span> |
| <span id="566">566</span> |
| <span id="567">567</span> |
| <span id="568">568</span> |
| <span id="569">569</span> |
| <span id="570">570</span> |
| <span id="571">571</span> |
| <span id="572">572</span> |
| <span id="573">573</span> |
| <span id="574">574</span> |
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| <span id="576">576</span> |
| <span id="577">577</span> |
| <span id="578">578</span> |
| <span id="579">579</span> |
| <span id="580">580</span> |
| <span id="581">581</span> |
| <span id="582">582</span> |
| <span id="583">583</span> |
| <span id="584">584</span> |
| <span id="585">585</span> |
| <span id="586">586</span> |
| <span id="587">587</span> |
| <span id="588">588</span> |
| <span id="589">589</span> |
| <span id="590">590</span> |
| <span id="591">591</span> |
| <span id="592">592</span> |
| <span id="593">593</span> |
| <span id="594">594</span> |
| <span id="595">595</span> |
| <span id="596">596</span> |
| <span id="597">597</span> |
| <span id="598">598</span> |
| <span id="599">599</span> |
| <span id="600">600</span> |
| <span id="601">601</span> |
| <span id="602">602</span> |
| <span id="603">603</span> |
| <span id="604">604</span> |
| <span id="605">605</span> |
| <span id="606">606</span> |
| <span id="607">607</span> |
| <span id="608">608</span> |
| <span id="609">609</span> |
| </pre><pre class="rust"><code><span class="kw">use crate</span>::{read_u16_from_be, read_u8}; |
| <span class="kw">use </span>error::{Error, <span class="prelude-ty">Result</span>, UnsupportedFeature}; |
| <span class="kw">use </span>huffman::{HuffmanTable, HuffmanTableClass}; |
| <span class="kw">use </span>marker::Marker; |
| <span class="kw">use </span>marker::Marker::<span class="kw-2">*</span>; |
| <span class="kw">use </span>std::io::{<span class="self">self</span>, Read}; |
| <span class="kw">use </span>std::ops::Range; |
| |
| <span class="attribute">#[derive(Clone, Copy, Debug, PartialEq)] |
| </span><span class="kw">pub struct </span>Dimensions { |
| <span class="kw">pub </span>width: u16, |
| <span class="kw">pub </span>height: u16, |
| } |
| |
| <span class="attribute">#[derive(Clone, Copy, Debug, PartialEq)] |
| </span><span class="kw">pub enum </span>EntropyCoding { |
| Huffman, |
| Arithmetic, |
| } |
| |
| <span class="attribute">#[derive(Clone, Copy, Debug, PartialEq)] |
| </span><span class="kw">pub enum </span>CodingProcess { |
| DctSequential, |
| DctProgressive, |
| Lossless, |
| } |
| |
| <span class="attribute">#[derive(Clone)] |
| </span><span class="kw">pub struct </span>FrameInfo { |
| <span class="kw">pub </span>is_baseline: bool, |
| <span class="kw">pub </span>is_differential: bool, |
| <span class="kw">pub </span>coding_process: CodingProcess, |
| <span class="kw">pub </span>entropy_coding: EntropyCoding, |
| <span class="kw">pub </span>precision: u8, |
| |
| <span class="kw">pub </span>image_size: Dimensions, |
| <span class="kw">pub </span>output_size: Dimensions, |
| <span class="kw">pub </span>mcu_size: Dimensions, |
| <span class="kw">pub </span>components: Vec<Component>, |
| } |
| |
| <span class="attribute">#[derive(Debug)] |
| </span><span class="kw">pub struct </span>ScanInfo { |
| <span class="kw">pub </span>component_indices: Vec<usize>, |
| <span class="kw">pub </span>dc_table_indices: Vec<usize>, |
| <span class="kw">pub </span>ac_table_indices: Vec<usize>, |
| |
| <span class="kw">pub </span>spectral_selection: Range<u8>, |
| <span class="kw">pub </span>successive_approximation_high: u8, |
| <span class="kw">pub </span>successive_approximation_low: u8, |
| } |
| |
| <span class="attribute">#[derive(Clone, Debug)] |
| </span><span class="kw">pub struct </span>Component { |
| <span class="kw">pub </span>identifier: u8, |
| |
| <span class="kw">pub </span>horizontal_sampling_factor: u8, |
| <span class="kw">pub </span>vertical_sampling_factor: u8, |
| |
| <span class="kw">pub </span>quantization_table_index: usize, |
| |
| <span class="kw">pub </span>dct_scale: usize, |
| |
| <span class="kw">pub </span>size: Dimensions, |
| <span class="kw">pub </span>block_size: Dimensions, |
| } |
| |
| <span class="attribute">#[derive(Debug)] |
| </span><span class="kw">pub enum </span>AppData { |
| Adobe(AdobeColorTransform), |
| Jfif, |
| Avi1, |
| Icc(IccChunk), |
| } |
| |
| <span class="comment">// http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html#Adobe |
| </span><span class="attribute">#[derive(Clone, Copy, Debug, PartialEq)] |
| </span><span class="kw">pub enum </span>AdobeColorTransform { |
| <span class="comment">// RGB or CMYK |
| </span>Unknown, |
| YCbCr, |
| <span class="comment">// YCbCrK |
| </span>YCCK, |
| } |
| <span class="attribute">#[derive(Debug)] |
| </span><span class="kw">pub struct </span>IccChunk { |
| <span class="kw">pub </span>num_markers: u8, |
| <span class="kw">pub </span>seq_no: u8, |
| <span class="kw">pub </span>data: Vec<u8>, |
| } |
| |
| <span class="kw">impl </span>FrameInfo { |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>update_idct_size(<span class="kw-2">&mut </span><span class="self">self</span>, idct_size: usize) -> <span class="prelude-ty">Result</span><()> { |
| <span class="kw">for </span>component <span class="kw">in </span><span class="kw-2">&mut </span><span class="self">self</span>.components { |
| component.dct_scale = idct_size; |
| } |
| |
| update_component_sizes(<span class="self">self</span>.image_size, <span class="kw-2">&mut </span><span class="self">self</span>.components)<span class="question-mark">?</span>; |
| |
| <span class="self">self</span>.output_size = Dimensions { |
| width: (<span class="self">self</span>.image_size.width <span class="kw">as </span>f32 * idct_size <span class="kw">as </span>f32 / <span class="number">8.0</span>).ceil() <span class="kw">as </span>u16, |
| height: (<span class="self">self</span>.image_size.height <span class="kw">as </span>f32 * idct_size <span class="kw">as </span>f32 / <span class="number">8.0</span>).ceil() <span class="kw">as </span>u16 |
| }; |
| |
| <span class="prelude-val">Ok</span>(()) |
| } |
| } |
| |
| <span class="kw">fn </span>read_length<R: Read>(reader: <span class="kw-2">&mut </span>R, marker: Marker) -> <span class="prelude-ty">Result</span><usize> { |
| <span class="macro">assert!</span>(marker.has_length()); |
| |
| <span class="comment">// length is including itself. |
| </span><span class="kw">let </span>length = usize::from(read_u16_from_be(reader)<span class="question-mark">?</span>); |
| |
| <span class="kw">if </span>length < <span class="number">2 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"encountered {:?} with invalid length {}"</span>, marker, length))); |
| } |
| |
| <span class="prelude-val">Ok</span>(length - <span class="number">2</span>) |
| } |
| |
| <span class="kw">fn </span>skip_bytes<R: Read>(reader: <span class="kw-2">&mut </span>R, length: usize) -> <span class="prelude-ty">Result</span><()> { |
| <span class="kw">let </span>length = length <span class="kw">as </span>u64; |
| <span class="kw">let </span>to_skip = <span class="kw-2">&mut </span>reader.by_ref().take(length); |
| <span class="kw">let </span>copied = io::copy(to_skip, <span class="kw-2">&mut </span>io::sink())<span class="question-mark">?</span>; |
| <span class="kw">if </span>copied < length { |
| <span class="prelude-val">Err</span>(Error::Io(io::ErrorKind::UnexpectedEof.into())) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Ok</span>(()) |
| } |
| } |
| |
| <span class="comment">// Section B.2.2 |
| </span><span class="kw">pub fn </span>parse_sof<R: Read>(reader: <span class="kw-2">&mut </span>R, marker: Marker) -> <span class="prelude-ty">Result</span><FrameInfo> { |
| <span class="kw">let </span>length = read_length(reader, marker)<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span>length <= <span class="number">6 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"invalid length in SOF"</span>.to_owned())); |
| } |
| |
| <span class="kw">let </span>is_baseline = marker == SOF(<span class="number">0</span>); |
| <span class="kw">let </span>is_differential = <span class="kw">match </span>marker { |
| SOF(<span class="number">0 </span>..= <span class="number">3</span>) | SOF(<span class="number">9 </span>..= <span class="number">11</span>) => <span class="bool-val">false</span>, |
| SOF(<span class="number">5 </span>..= <span class="number">7</span>) | SOF(<span class="number">13 </span>..= <span class="number">15</span>) => <span class="bool-val">true</span>, |
| <span class="kw">_ </span>=> <span class="macro">panic!</span>(), |
| }; |
| <span class="kw">let </span>coding_process = <span class="kw">match </span>marker { |
| SOF(<span class="number">0</span>) | SOF(<span class="number">1</span>) | SOF(<span class="number">5</span>) | SOF(<span class="number">9</span>) | SOF(<span class="number">13</span>) => CodingProcess::DctSequential, |
| SOF(<span class="number">2</span>) | SOF(<span class="number">6</span>) | SOF(<span class="number">10</span>) | SOF(<span class="number">14</span>) => CodingProcess::DctProgressive, |
| SOF(<span class="number">3</span>) | SOF(<span class="number">7</span>) | SOF(<span class="number">11</span>) | SOF(<span class="number">15</span>) => CodingProcess::Lossless, |
| <span class="kw">_ </span>=> <span class="macro">panic!</span>(), |
| }; |
| <span class="kw">let </span>entropy_coding = <span class="kw">match </span>marker { |
| SOF(<span class="number">0 </span>..= <span class="number">3</span>) | SOF(<span class="number">5 </span>..= <span class="number">7</span>) => EntropyCoding::Huffman, |
| SOF(<span class="number">9 </span>..= <span class="number">11</span>) | SOF(<span class="number">13 </span>..= <span class="number">15</span>) => EntropyCoding::Arithmetic, |
| <span class="kw">_ </span>=> <span class="macro">panic!</span>(), |
| }; |
| |
| <span class="kw">let </span>precision = read_u8(reader)<span class="question-mark">?</span>; |
| |
| <span class="kw">match </span>precision { |
| <span class="number">8 </span>=> {}, |
| <span class="number">12 </span>=> { |
| <span class="kw">if </span>is_baseline { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"12 bit sample precision is not allowed in baseline"</span>.to_owned())); |
| } |
| }, |
| <span class="kw">_ </span>=> { |
| <span class="kw">if </span>coding_process != CodingProcess::Lossless { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid precision {} in frame header"</span>, precision))) |
| } |
| }, |
| } |
| |
| <span class="kw">let </span>height = read_u16_from_be(reader)<span class="question-mark">?</span>; |
| <span class="kw">let </span>width = read_u16_from_be(reader)<span class="question-mark">?</span>; |
| |
| <span class="comment">// height: |
| // "Value 0 indicates that the number of lines shall be defined by the DNL marker and |
| // parameters at the end of the first scan (see B.2.5)." |
| </span><span class="kw">if </span>height == <span class="number">0 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Unsupported(UnsupportedFeature::DNL)); |
| } |
| |
| <span class="kw">if </span>width == <span class="number">0 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"zero width in frame header"</span>.to_owned())); |
| } |
| |
| <span class="kw">let </span>component_count = read_u8(reader)<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span>component_count == <span class="number">0 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"zero component count in frame header"</span>.to_owned())); |
| } |
| <span class="kw">if </span>coding_process == CodingProcess::DctProgressive && component_count > <span class="number">4 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"progressive frame with more than 4 components"</span>.to_owned())); |
| } |
| |
| <span class="kw">if </span>length != <span class="number">6 </span>+ <span class="number">3 </span>* component_count <span class="kw">as </span>usize { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"invalid length in SOF"</span>.to_owned())); |
| } |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>components: Vec<Component> = Vec::with_capacity(component_count <span class="kw">as </span>usize); |
| |
| <span class="kw">for _ in </span><span class="number">0 </span>.. component_count { |
| <span class="kw">let </span>identifier = read_u8(reader)<span class="question-mark">?</span>; |
| |
| <span class="comment">// Each component's identifier must be unique. |
| </span><span class="kw">if </span>components.iter().any(|c| c.identifier == identifier) { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"duplicate frame component identifier {}"</span>, identifier))); |
| } |
| |
| <span class="kw">let </span>byte = read_u8(reader)<span class="question-mark">?</span>; |
| <span class="kw">let </span>horizontal_sampling_factor = byte >> <span class="number">4</span>; |
| <span class="kw">let </span>vertical_sampling_factor = byte & <span class="number">0x0f</span>; |
| |
| <span class="kw">if </span>horizontal_sampling_factor == <span class="number">0 </span>|| horizontal_sampling_factor > <span class="number">4 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid horizontal sampling factor {}"</span>, horizontal_sampling_factor))); |
| } |
| <span class="kw">if </span>vertical_sampling_factor == <span class="number">0 </span>|| vertical_sampling_factor > <span class="number">4 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid vertical sampling factor {}"</span>, vertical_sampling_factor))); |
| } |
| |
| <span class="kw">let </span>quantization_table_index = read_u8(reader)<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span>quantization_table_index > <span class="number">3 </span>|| (coding_process == CodingProcess::Lossless && quantization_table_index != <span class="number">0</span>) { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid quantization table index {}"</span>, quantization_table_index))); |
| } |
| |
| components.push(Component { |
| identifier: identifier, |
| horizontal_sampling_factor: horizontal_sampling_factor, |
| vertical_sampling_factor: vertical_sampling_factor, |
| quantization_table_index: quantization_table_index <span class="kw">as </span>usize, |
| dct_scale: <span class="number">8</span>, |
| size: Dimensions {width: <span class="number">0</span>, height: <span class="number">0</span>}, |
| block_size: Dimensions {width: <span class="number">0</span>, height: <span class="number">0</span>}, |
| }); |
| } |
| |
| <span class="kw">let </span>mcu_size = update_component_sizes(Dimensions { width, height }, <span class="kw-2">&mut </span>components)<span class="question-mark">?</span>; |
| |
| <span class="prelude-val">Ok</span>(FrameInfo { |
| is_baseline: is_baseline, |
| is_differential: is_differential, |
| coding_process: coding_process, |
| entropy_coding: entropy_coding, |
| precision: precision, |
| image_size: Dimensions { width, height }, |
| output_size: Dimensions { width, height }, |
| mcu_size, |
| components: components, |
| }) |
| } |
| |
| <span class="doccomment">/// Returns ceil(x/y), requires x>0 |
| </span><span class="kw">fn </span>ceil_div(x: u32, y: u32) -> <span class="prelude-ty">Result</span><u16> { |
| <span class="kw">if </span>x == <span class="number">0 </span>|| y == <span class="number">0 </span>{ |
| <span class="comment">// TODO Determine how this error is reached. Can we validate input |
| // earlier and error out then? |
| </span><span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"invalid dimensions"</span>.to_owned())); |
| } |
| <span class="prelude-val">Ok</span>((<span class="number">1 </span>+ ((x - <span class="number">1</span>) / y)) <span class="kw">as </span>u16) |
| } |
| |
| <span class="kw">fn </span>update_component_sizes(size: Dimensions, components: <span class="kw-2">&mut </span>[Component]) -> <span class="prelude-ty">Result</span><Dimensions> { |
| <span class="kw">let </span>h_max = components.iter().map(|c| c.horizontal_sampling_factor).max().unwrap() <span class="kw">as </span>u32; |
| <span class="kw">let </span>v_max = components.iter().map(|c| c.vertical_sampling_factor).max().unwrap() <span class="kw">as </span>u32; |
| |
| <span class="kw">let </span>mcu_size = Dimensions { |
| width: ceil_div(size.width <span class="kw">as </span>u32, h_max * <span class="number">8</span>)<span class="question-mark">?</span>, |
| height: ceil_div(size.height <span class="kw">as </span>u32, v_max * <span class="number">8</span>)<span class="question-mark">?</span>, |
| }; |
| |
| <span class="kw">for </span>component <span class="kw">in </span>components { |
| component.size.width = ceil_div(size.width <span class="kw">as </span>u32 * component.horizontal_sampling_factor <span class="kw">as </span>u32 * component.dct_scale <span class="kw">as </span>u32, h_max * <span class="number">8</span>)<span class="question-mark">?</span>; |
| component.size.height = ceil_div(size.height <span class="kw">as </span>u32 * component.vertical_sampling_factor <span class="kw">as </span>u32 * component.dct_scale <span class="kw">as </span>u32, v_max * <span class="number">8</span>)<span class="question-mark">?</span>; |
| |
| component.block_size.width = mcu_size.width * component.horizontal_sampling_factor <span class="kw">as </span>u16; |
| component.block_size.height = mcu_size.height * component.vertical_sampling_factor <span class="kw">as </span>u16; |
| } |
| |
| <span class="prelude-val">Ok</span>(mcu_size) |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>test_update_component_sizes() { |
| <span class="kw">let </span><span class="kw-2">mut </span>components = [Component { |
| identifier: <span class="number">1</span>, |
| horizontal_sampling_factor: <span class="number">2</span>, |
| vertical_sampling_factor: <span class="number">2</span>, |
| quantization_table_index: <span class="number">0</span>, |
| dct_scale: <span class="number">8</span>, |
| size: Dimensions { width: <span class="number">0</span>, height: <span class="number">0 </span>}, |
| block_size: Dimensions { width: <span class="number">0</span>, height: <span class="number">0 </span>}, |
| }]; |
| <span class="kw">let </span>mcu = update_component_sizes( |
| Dimensions { width: <span class="number">800</span>, height: <span class="number">280 </span>}, |
| <span class="kw-2">&mut </span>components).unwrap(); |
| <span class="macro">assert_eq!</span>(mcu, Dimensions { width: <span class="number">50</span>, height: <span class="number">18 </span>}); |
| <span class="macro">assert_eq!</span>(components[<span class="number">0</span>].block_size, Dimensions { width: <span class="number">100</span>, height: <span class="number">36 </span>}); |
| <span class="macro">assert_eq!</span>(components[<span class="number">0</span>].size, Dimensions { width: <span class="number">800</span>, height: <span class="number">280 </span>}); |
| } |
| |
| <span class="comment">// Section B.2.3 |
| </span><span class="kw">pub fn </span>parse_sos<R: Read>(reader: <span class="kw-2">&mut </span>R, frame: <span class="kw-2">&</span>FrameInfo) -> <span class="prelude-ty">Result</span><ScanInfo> { |
| <span class="kw">let </span>length = read_length(reader, SOS)<span class="question-mark">?</span>; |
| <span class="kw">if </span><span class="number">0 </span>== length { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"zero length in SOS"</span>.to_owned())); |
| } |
| |
| <span class="kw">let </span>component_count = read_u8(reader)<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span>component_count == <span class="number">0 </span>|| component_count > <span class="number">4 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid component count {} in scan header"</span>, component_count))); |
| } |
| |
| <span class="kw">if </span>length != <span class="number">4 </span>+ <span class="number">2 </span>* component_count <span class="kw">as </span>usize { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"invalid length in SOS"</span>.to_owned())); |
| } |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>component_indices = Vec::with_capacity(component_count <span class="kw">as </span>usize); |
| <span class="kw">let </span><span class="kw-2">mut </span>dc_table_indices = Vec::with_capacity(component_count <span class="kw">as </span>usize); |
| <span class="kw">let </span><span class="kw-2">mut </span>ac_table_indices = Vec::with_capacity(component_count <span class="kw">as </span>usize); |
| |
| <span class="kw">for _ in </span><span class="number">0 </span>.. component_count { |
| <span class="kw">let </span>identifier = read_u8(reader)<span class="question-mark">?</span>; |
| |
| <span class="kw">let </span>component_index = <span class="kw">match </span>frame.components.iter().position(|c| c.identifier == identifier) { |
| <span class="prelude-val">Some</span>(value) => value, |
| <span class="prelude-val">None </span>=> <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"scan component identifier {} does not match any of the component identifiers defined in the frame"</span>, identifier))), |
| }; |
| |
| <span class="comment">// Each of the scan's components must be unique. |
| </span><span class="kw">if </span>component_indices.contains(<span class="kw-2">&</span>component_index) { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"duplicate scan component identifier {}"</span>, identifier))); |
| } |
| |
| <span class="comment">// "... the ordering in the scan header shall follow the ordering in the frame header." |
| </span><span class="kw">if </span>component_index < <span class="kw-2">*</span>component_indices.iter().max().unwrap_or(<span class="kw-2">&</span><span class="number">0</span>) { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"the scan component order does not follow the order in the frame header"</span>.to_owned())); |
| } |
| |
| <span class="kw">let </span>byte = read_u8(reader)<span class="question-mark">?</span>; |
| <span class="kw">let </span>dc_table_index = byte >> <span class="number">4</span>; |
| <span class="kw">let </span>ac_table_index = byte & <span class="number">0x0f</span>; |
| |
| <span class="kw">if </span>dc_table_index > <span class="number">3 </span>|| (frame.is_baseline && dc_table_index > <span class="number">1</span>) { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid dc table index {}"</span>, dc_table_index))); |
| } |
| <span class="kw">if </span>ac_table_index > <span class="number">3 </span>|| (frame.is_baseline && ac_table_index > <span class="number">1</span>) { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid ac table index {}"</span>, ac_table_index))); |
| } |
| |
| component_indices.push(component_index); |
| dc_table_indices.push(dc_table_index <span class="kw">as </span>usize); |
| ac_table_indices.push(ac_table_index <span class="kw">as </span>usize); |
| } |
| |
| <span class="kw">let </span>blocks_per_mcu = component_indices.iter().map(|<span class="kw-2">&</span>i| { |
| frame.components[i].horizontal_sampling_factor <span class="kw">as </span>u32 * frame.components[i].vertical_sampling_factor <span class="kw">as </span>u32 |
| }).fold(<span class="number">0</span>, ::std::ops::Add::add); |
| |
| <span class="kw">if </span>component_count > <span class="number">1 </span>&& blocks_per_mcu > <span class="number">10 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"scan with more than one component and more than 10 blocks per MCU"</span>.to_owned())); |
| } |
| |
| <span class="kw">let </span>spectral_selection_start = read_u8(reader)<span class="question-mark">?</span>; |
| <span class="kw">let </span>spectral_selection_end = read_u8(reader)<span class="question-mark">?</span>; |
| |
| <span class="kw">let </span>byte = read_u8(reader)<span class="question-mark">?</span>; |
| <span class="kw">let </span>successive_approximation_high = byte >> <span class="number">4</span>; |
| <span class="kw">let </span>successive_approximation_low = byte & <span class="number">0x0f</span>; |
| |
| <span class="kw">if </span>frame.coding_process == CodingProcess::DctProgressive { |
| <span class="kw">if </span>spectral_selection_end > <span class="number">63 </span>|| spectral_selection_start > spectral_selection_end || |
| (spectral_selection_start == <span class="number">0 </span>&& spectral_selection_end != <span class="number">0</span>) { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid spectral selection parameters: ss={}, se={}"</span>, spectral_selection_start, spectral_selection_end))); |
| } |
| <span class="kw">if </span>spectral_selection_start != <span class="number">0 </span>&& component_count != <span class="number">1 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"spectral selection scan with AC coefficients can't have more than one component"</span>.to_owned())); |
| } |
| |
| <span class="kw">if </span>successive_approximation_high > <span class="number">13 </span>|| successive_approximation_low > <span class="number">13 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid successive approximation parameters: ah={}, al={}"</span>, successive_approximation_high, successive_approximation_low))); |
| } |
| |
| <span class="comment">// Section G.1.1.1.2 |
| // "Each scan which follows the first scan for a given band progressively improves |
| // the precision of the coefficients by one bit, until full precision is reached." |
| </span><span class="kw">if </span>successive_approximation_high != <span class="number">0 </span>&& successive_approximation_high != successive_approximation_low + <span class="number">1 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"successive approximation scan with more than one bit of improvement"</span>.to_owned())); |
| } |
| } |
| <span class="kw">else </span>{ |
| <span class="kw">if </span>spectral_selection_start != <span class="number">0 </span>|| spectral_selection_end != <span class="number">63 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"spectral selection is not allowed in non-progressive scan"</span>.to_owned())); |
| } |
| <span class="kw">if </span>successive_approximation_high != <span class="number">0 </span>|| successive_approximation_low != <span class="number">0 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"successive approximation is not allowed in non-progressive scan"</span>.to_owned())); |
| } |
| } |
| |
| <span class="prelude-val">Ok</span>(ScanInfo { |
| component_indices: component_indices, |
| dc_table_indices: dc_table_indices, |
| ac_table_indices: ac_table_indices, |
| spectral_selection: Range { |
| start: spectral_selection_start, |
| end: spectral_selection_end + <span class="number">1</span>, |
| }, |
| successive_approximation_high: successive_approximation_high, |
| successive_approximation_low: successive_approximation_low, |
| }) |
| } |
| |
| <span class="comment">// Section B.2.4.1 |
| </span><span class="kw">pub fn </span>parse_dqt<R: Read>(reader: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Result</span><[<span class="prelude-ty">Option</span><[u16; <span class="number">64</span>]>; <span class="number">4</span>]> { |
| <span class="kw">let </span><span class="kw-2">mut </span>length = read_length(reader, DQT)<span class="question-mark">?</span>; |
| <span class="kw">let </span><span class="kw-2">mut </span>tables = [<span class="prelude-val">None</span>; <span class="number">4</span>]; |
| |
| <span class="comment">// Each DQT segment may contain multiple quantization tables. |
| </span><span class="kw">while </span>length > <span class="number">0 </span>{ |
| <span class="kw">let </span>byte = read_u8(reader)<span class="question-mark">?</span>; |
| <span class="kw">let </span>precision = (byte >> <span class="number">4</span>) <span class="kw">as </span>usize; |
| <span class="kw">let </span>index = (byte & <span class="number">0x0f</span>) <span class="kw">as </span>usize; |
| |
| <span class="comment">// The combination of 8-bit sample precision and 16-bit quantization tables is explicitly |
| // disallowed by the JPEG spec: |
| // "An 8-bit DCT-based process shall not use a 16-bit precision quantization table." |
| // "Pq: Quantization table element precision – Specifies the precision of the Qk |
| // values. Value 0 indicates 8-bit Qk values; value 1 indicates 16-bit Qk values. Pq |
| // shall be zero for 8 bit sample precision P (see B.2.2)." |
| // libjpeg allows this behavior though, and there are images in the wild using it. So to |
| // match libjpeg's behavior we are deviating from the JPEG spec here. |
| </span><span class="kw">if </span>precision > <span class="number">1 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid precision {} in DQT"</span>, precision))); |
| } |
| <span class="kw">if </span>index > <span class="number">3 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid destination identifier {} in DQT"</span>, index))); |
| } |
| <span class="kw">if </span>length < <span class="number">65 </span>+ <span class="number">64 </span>* precision { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"invalid length in DQT"</span>.to_owned())); |
| } |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>table = [<span class="number">0u16</span>; <span class="number">64</span>]; |
| |
| <span class="kw">for </span>item <span class="kw">in </span>table.iter_mut() { |
| <span class="kw-2">*</span>item = <span class="kw">match </span>precision { |
| <span class="number">0 </span>=> u16::from(read_u8(reader)<span class="question-mark">?</span>), |
| <span class="number">1 </span>=> read_u16_from_be(reader)<span class="question-mark">?</span>, |
| <span class="kw">_ </span>=> <span class="macro">unreachable!</span>(), |
| }; |
| } |
| |
| <span class="kw">if </span>table.iter().any(|<span class="kw-2">&</span>val| val == <span class="number">0</span>) { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"quantization table contains element with a zero value"</span>.to_owned())); |
| } |
| |
| tables[index] = <span class="prelude-val">Some</span>(table); |
| length -= <span class="number">65 </span>+ <span class="number">64 </span>* precision; |
| } |
| |
| <span class="prelude-val">Ok</span>(tables) |
| } |
| |
| <span class="comment">// Section B.2.4.2 |
| </span><span class="kw">pub fn </span>parse_dht<R: Read>(reader: <span class="kw-2">&mut </span>R, is_baseline: <span class="prelude-ty">Option</span><bool>) -> <span class="prelude-ty">Result</span><(Vec<<span class="prelude-ty">Option</span><HuffmanTable>>, Vec<<span class="prelude-ty">Option</span><HuffmanTable>>)> { |
| <span class="kw">let </span><span class="kw-2">mut </span>length = read_length(reader, DHT)<span class="question-mark">?</span>; |
| <span class="kw">let </span><span class="kw-2">mut </span>dc_tables = <span class="macro">vec!</span>[<span class="prelude-val">None</span>, <span class="prelude-val">None</span>, <span class="prelude-val">None</span>, <span class="prelude-val">None</span>]; |
| <span class="kw">let </span><span class="kw-2">mut </span>ac_tables = <span class="macro">vec!</span>[<span class="prelude-val">None</span>, <span class="prelude-val">None</span>, <span class="prelude-val">None</span>, <span class="prelude-val">None</span>]; |
| |
| <span class="comment">// Each DHT segment may contain multiple huffman tables. |
| </span><span class="kw">while </span>length > <span class="number">17 </span>{ |
| <span class="kw">let </span>byte = read_u8(reader)<span class="question-mark">?</span>; |
| <span class="kw">let </span>class = byte >> <span class="number">4</span>; |
| <span class="kw">let </span>index = (byte & <span class="number">0x0f</span>) <span class="kw">as </span>usize; |
| |
| <span class="kw">if </span>class != <span class="number">0 </span>&& class != <span class="number">1 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid class {} in DHT"</span>, class))); |
| } |
| <span class="kw">if </span>is_baseline == <span class="prelude-val">Some</span>(<span class="bool-val">true</span>) && index > <span class="number">1 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"a maximum of two huffman tables per class are allowed in baseline"</span>.to_owned())); |
| } |
| <span class="kw">if </span>index > <span class="number">3 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="macro">format!</span>(<span class="string">"invalid destination identifier {} in DHT"</span>, index))); |
| } |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>counts = [<span class="number">0u8</span>; <span class="number">16</span>]; |
| reader.read_exact(<span class="kw-2">&mut </span>counts)<span class="question-mark">?</span>; |
| |
| <span class="kw">let </span>size = counts.iter().map(|<span class="kw-2">&</span>val| val <span class="kw">as </span>usize).fold(<span class="number">0</span>, ::std::ops::Add::add); |
| |
| <span class="kw">if </span>size == <span class="number">0 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"encountered table with zero length in DHT"</span>.to_owned())); |
| } |
| <span class="kw">else if </span>size > <span class="number">256 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"encountered table with excessive length in DHT"</span>.to_owned())); |
| } |
| <span class="kw">else if </span>size > length - <span class="number">17 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"invalid length in DHT"</span>.to_owned())); |
| } |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>values = <span class="macro">vec!</span>[<span class="number">0u8</span>; size]; |
| reader.read_exact(<span class="kw-2">&mut </span>values)<span class="question-mark">?</span>; |
| |
| <span class="kw">match </span>class { |
| <span class="number">0 </span>=> dc_tables[index] = <span class="prelude-val">Some</span>(HuffmanTable::new(<span class="kw-2">&</span>counts, <span class="kw-2">&</span>values, HuffmanTableClass::DC)<span class="question-mark">?</span>), |
| <span class="number">1 </span>=> ac_tables[index] = <span class="prelude-val">Some</span>(HuffmanTable::new(<span class="kw-2">&</span>counts, <span class="kw-2">&</span>values, HuffmanTableClass::AC)<span class="question-mark">?</span>), |
| <span class="kw">_ </span>=> <span class="macro">unreachable!</span>(), |
| } |
| |
| length -= <span class="number">17 </span>+ size; |
| } |
| |
| <span class="kw">if </span>length != <span class="number">0 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"invalid length in DHT"</span>.to_owned())); |
| } |
| |
| <span class="prelude-val">Ok</span>((dc_tables, ac_tables)) |
| } |
| |
| <span class="comment">// Section B.2.4.4 |
| </span><span class="kw">pub fn </span>parse_dri<R: Read>(reader: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Result</span><u16> { |
| <span class="kw">let </span>length = read_length(reader, DRI)<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span>length != <span class="number">2 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"DRI with invalid length"</span>.to_owned())); |
| } |
| |
| <span class="prelude-val">Ok</span>(read_u16_from_be(reader)<span class="question-mark">?</span>) |
| } |
| |
| <span class="comment">// Section B.2.4.5 |
| </span><span class="kw">pub fn </span>parse_com<R: Read>(reader: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Result</span><Vec<u8>> { |
| <span class="kw">let </span>length = read_length(reader, COM)<span class="question-mark">?</span>; |
| <span class="kw">let </span><span class="kw-2">mut </span>buffer = <span class="macro">vec!</span>[<span class="number">0u8</span>; length]; |
| |
| reader.read_exact(<span class="kw-2">&mut </span>buffer)<span class="question-mark">?</span>; |
| |
| <span class="prelude-val">Ok</span>(buffer) |
| } |
| |
| <span class="comment">// Section B.2.4.6 |
| </span><span class="kw">pub fn </span>parse_app<R: Read>(reader: <span class="kw-2">&mut </span>R, marker: Marker) -> <span class="prelude-ty">Result</span><<span class="prelude-ty">Option</span><AppData>> { |
| <span class="kw">let </span>length = read_length(reader, marker)<span class="question-mark">?</span>; |
| <span class="kw">let </span><span class="kw-2">mut </span>bytes_read = <span class="number">0</span>; |
| <span class="kw">let </span><span class="kw-2">mut </span>result = <span class="prelude-val">None</span>; |
| |
| <span class="kw">match </span>marker { |
| APP(<span class="number">0</span>) => { |
| <span class="kw">if </span>length >= <span class="number">5 </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>buffer = [<span class="number">0u8</span>; <span class="number">5</span>]; |
| reader.read_exact(<span class="kw-2">&mut </span>buffer)<span class="question-mark">?</span>; |
| bytes_read = buffer.len(); |
| |
| <span class="comment">// http://www.w3.org/Graphics/JPEG/jfif3.pdf |
| </span><span class="kw">if </span><span class="kw-2">&</span>buffer[<span class="number">0 </span>.. <span class="number">5</span>] == <span class="kw-2">&</span>[<span class="string">b'J'</span>, <span class="string">b'F'</span>, <span class="string">b'I'</span>, <span class="string">b'F'</span>, <span class="string">b'\0'</span>] { |
| result = <span class="prelude-val">Some</span>(AppData::Jfif); |
| <span class="comment">// https://sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html#AVI1 |
| </span>} <span class="kw">else if </span><span class="kw-2">&</span>buffer[<span class="number">0 </span>.. <span class="number">5</span>] == <span class="kw-2">&</span>[<span class="string">b'A'</span>, <span class="string">b'V'</span>, <span class="string">b'I'</span>, <span class="string">b'1'</span>, <span class="string">b'\0'</span>] { |
| result = <span class="prelude-val">Some</span>(AppData::Avi1); |
| } |
| } |
| } |
| APP(<span class="number">2</span>) => { |
| <span class="kw">if </span>length > <span class="number">14 </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>buffer = [<span class="number">0u8</span>; <span class="number">14</span>]; |
| reader.read_exact(<span class="kw-2">&mut </span>buffer)<span class="question-mark">?</span>; |
| bytes_read = buffer.len(); |
| |
| <span class="comment">// http://www.color.org/ICC_Minor_Revision_for_Web.pdf |
| // B.4 Embedding ICC profiles in JFIF files |
| </span><span class="kw">if </span><span class="kw-2">&</span>buffer[<span class="number">0</span>..<span class="number">12</span>] == <span class="string">b"ICC_PROFILE\0" </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>data = <span class="macro">vec!</span>[<span class="number">0</span>; length - bytes_read]; |
| reader.read_exact(<span class="kw-2">&mut </span>data)<span class="question-mark">?</span>; |
| bytes_read += data.len(); |
| result = <span class="prelude-val">Some</span>(AppData::Icc(IccChunk { |
| seq_no: buffer[<span class="number">12</span>], |
| num_markers: buffer[<span class="number">13</span>], |
| data, |
| })); |
| } |
| } |
| } |
| APP(<span class="number">14</span>) => { |
| <span class="kw">if </span>length >= <span class="number">12 </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>buffer = [<span class="number">0u8</span>; <span class="number">12</span>]; |
| reader.read_exact(<span class="kw-2">&mut </span>buffer)<span class="question-mark">?</span>; |
| bytes_read = buffer.len(); |
| |
| <span class="comment">// http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html#Adobe |
| </span><span class="kw">if </span><span class="kw-2">&</span>buffer[<span class="number">0 </span>.. <span class="number">6</span>] == <span class="kw-2">&</span>[<span class="string">b'A'</span>, <span class="string">b'd'</span>, <span class="string">b'o'</span>, <span class="string">b'b'</span>, <span class="string">b'e'</span>, <span class="string">b'\0'</span>] { |
| <span class="kw">let </span>color_transform = <span class="kw">match </span>buffer[<span class="number">11</span>] { |
| <span class="number">0 </span>=> AdobeColorTransform::Unknown, |
| <span class="number">1 </span>=> AdobeColorTransform::YCbCr, |
| <span class="number">2 </span>=> AdobeColorTransform::YCCK, |
| <span class="kw">_ </span>=> <span class="kw">return </span><span class="prelude-val">Err</span>(Error::Format(<span class="string">"invalid color transform in adobe app segment"</span>.to_owned())), |
| }; |
| |
| result = <span class="prelude-val">Some</span>(AppData::Adobe(color_transform)); |
| } |
| } |
| }, |
| <span class="kw">_ </span>=> {}, |
| } |
| |
| skip_bytes(reader, length - bytes_read)<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(result) |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="jpeg_decoder" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
