From 3427b060ab56a75bd1e25abf8dbe117bed563ccd Mon Sep 17 00:00:00 2001
From: Yannis Guyon <yguyon@google.com>
Date: Mon, 21 Oct 2024 14:35:06 +0000
Subject: [PATCH] Add references in the Sample Transform sections (#263)

SHA: b89eb19eb2cd1f0ef43e92750212d143da93b92f
Reason: push, by y-guyon

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
---
 index.html | 70 ++++++++++++++++++++++++++++--------------------------
 1 file changed, 36 insertions(+), 34 deletions(-)

diff --git a/index.html b/index.html
index b7a9229..6c4d854 100644
--- a/index.html
+++ b/index.html
@@ -1490,7 +1490,7 @@
 </style>
   <meta content="Bikeshed version 82ce88815, updated Thu Sep 7 16:33:55 2023 -0700" name="generator">
   <link href="https://AOMediaCodec.github.io/av1-avif" rel="canonical">
-  <meta content="b1a66afc159373f7e838d8056b3ebb1727dfc280" name="document-revision">
+  <meta content="b89eb19eb2cd1f0ef43e92750212d143da93b92f" name="document-revision">
 <style>/* Boilerplate: style-autolinks */
 .css.css, .property.property, .descriptor.descriptor {
     color: var(--a-normal-text);
@@ -2290,7 +2290,7 @@ <h3 class="heading settled" data-level="2.1" id="image-item"><span class="secno"
    <p class="note" role="note"><span class="marker">NOTE:</span> File writers may want to set the <code><a data-link-type="dfn" href="https://aomediacodec.github.io/av1-spec/av1-spec.pdf" id="ref-for-something⑧">still_picture</a></code> and <code><a data-link-type="dfn" href="https://aomediacodec.github.io/av1-spec/av1-spec.pdf" id="ref-for-something⑨">reduced_still_picture_header</a></code> flags to 1 when possible in the <a data-link-type="dfn" href="https://aomediacodec.github.io/av1-spec/av1-spec.pdf" id="ref-for-something①⓪">Sequence Header OBU</a> part of the <a data-link-type="dfn" href="#av1-image-item-data" id="ref-for-av1-image-item-data②">AV1 Image Item Data</a> so that AV1 header overhead is minimized.</p>
    <h3 class="heading settled" data-level="2.2" id="image-item-properties"><span class="secno">2.2. </span><span class="content">Image Item Properties</span><a class="self-link" href="#image-item-properties"></a></h3>
    <h4 class="heading settled" data-level="2.2.1" id="av1-item-configuration-property"><span class="secno">2.2.1. </span><span class="content">AV1 Item Configuration Property</span><a class="self-link" href="#av1-item-configuration-property"></a></h4>
-<pre class="def">Box Type:                 <dfn class="dfn-paneled" data-dfn-for="AV1ItemConfigurationProperty" data-dfn-type="dfn" data-export id="av1itemconfigurationproperty-av1c">av1C</dfn>
+<pre class="def">Box Type:                 <dfn data-dfn-for="AV1ItemConfigurationProperty" data-dfn-type="dfn" data-export id="av1itemconfigurationproperty-av1c">av1C<a class="self-link" href="#av1itemconfigurationproperty-av1c"></a></dfn>
 Property type:            Descriptive item property
 Container:                ItemPropertyContainerBox
 Mandatory (per item):     Yes, for an image item of type <code>'av01'</code>, no otherwise
@@ -2411,29 +2411,30 @@ <h4 class="heading settled" data-level="4.2.3" id="sample-transform"><span class
    <p>With a <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="sample-transform-derived-image-item">Sample Transform Derived Image Item</dfn>, pixels at the same position in multiple input image items can be combined into a single output pixel using basic mathematical operations. This can for example be used to work around codec limitations or for storing alterations to an image as non-destructive residuals. With a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①">Sample Transform Derived Image Item</a> it is possible for <a data-link-type="dfn" href="#avif" id="ref-for-avif⑤">AVIF</a> to support 16 or more bits of precision per sample, while still offering backward compatibility through a regular 8 to 12-bit <a data-link-type="dfn" href="#av1-image-item" id="ref-for-av1-image-item①⑦">AV1 Image Item</a> containing the most significant bits of each sample.</p>
    <p>In these sections, a "sample" refers to the value of a pixel for a given channel.</p>
    <h5 class="no-toc heading settled" data-level="4.2.3.1" id="sample-transform-definition"><span class="secno">4.2.3.1. </span><span class="content">Definition</span><a class="self-link" href="#sample-transform-definition"></a></h5>
-   <p>When a <a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①⓪⑤">derived image item</a> is of type <dfn data-dfn-for="Sample Transform Derived Image Item Type" data-dfn-type="dfn" data-export id="sample-transform-derived-image-item-type-sato">sato<a class="self-link" href="#sample-transform-derived-image-item-type-sato"></a></dfn>, it is called a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item②">Sample Transform Derived Image Item</a>, and its reconstructed image is formed from a set of input image items, <a data-link-type="dfn" href="#sato-constant" id="ref-for-sato-constant">constants</a> and <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator">operators</a>.</p>
+   <p>When a <a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①⓪⑤">derived image item</a> is of type <code>'<dfn data-dfn-for="Sample Transform Derived Image Item Type" data-dfn-type="dfn" data-export id="sample-transform-derived-image-item-type-sato">sato<a class="self-link" href="#sample-transform-derived-image-item-type-sato"></a></dfn>'</code>, it is called a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item②">Sample Transform Derived Image Item</a>, and its reconstructed image is formed from a set of input image items, <a data-link-type="dfn" href="#sato-constant" id="ref-for-sato-constant">constants</a> and <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator">operators</a>.</p>
    <p>The input images are specified in the <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①⓪⑥">SingleItemTypeReferenceBox</a></code> or <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①⓪⑦">SingleItemTypeReferenceBoxLarge</a></code> entries of type <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①⓪⑧">dimg</a>'</code> for this <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item③">Sample Transform Derived Image Item</a> within the <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①⓪⑨">ItemReferenceBox</a></code>. The input images are in the same order as specified in these entries. In the <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①①⓪">SingleItemTypeReferenceBox</a></code> or <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①①①">SingleItemTypeReferenceBoxLarge</a></code> of type <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①①②">dimg</a>'</code>, the value of the <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①①③">from_item_ID</a></code> field identifies the <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item④">Sample Transform Derived Image Item</a>, and the values of the <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①①④">to_item_ID</a></code> field identify the input images. There are <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①①⑤">reference_count</a></code> input image items as specified by the <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①①⑥">ItemReferenceBox</a></code>.</p>
    <p>The input image items and the <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item⑤">Sample Transform Derived Image Item</a> shall:</p>
    <ul>
     <li data-md>
-     <p>each be associated with a <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①①⑦">pixi</a>'</code> property and an <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①①⑧">ispe</a>'</code> property;</p>
+     <p>each be associated with a <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①①⑦">PixelInformationProperty</a></code> and an <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①①⑧">ispe</a>'</code> property;</p>
     <li data-md>
-     <p>have the same number of channels and the same chroma subsampling (or lack thereof) as defined by the <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①①⑨">pixi</a>'</code> and <code>'<a data-link-type="dfn" href="#av1itemconfigurationproperty-av1c" id="ref-for-av1itemconfigurationproperty-av1c">av1C</a>'</code> properties;</p>
+     <p>have the same number of channels and the same chroma subsampling (or lack thereof) as defined by the <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①①⑨">PixelInformationProperty</a></code> and <code><a data-link-type="dfn" href="#av1itemconfigurationproperty" id="ref-for-av1itemconfigurationproperty⑥">AV1ItemConfigurationProperty</a></code>;</p>
     <li data-md>
      <p>have the same dimensions as defined by the <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①②⓪">ispe</a>'</code> property;</p>
     <li data-md>
-     <p>have the same color information as defined by the <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②①">colr</a>'</code> properties (or lack thereof).</p>
+     <p>have the same color information as defined by the <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②①">ColourInformationBox</a></code> properties (or lack thereof).</p>
    </ul>
-   <p>Each output sample of the <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item⑥">Sample Transform Derived Image Item</a> is obtained by evaluating an expression consisting of a series of integer <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator①">operators</a> and <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand">operands</a>. An <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand①">operand</a> is a constant or a sample from an input image item located at the same channel index and at the same spatial coordinates as the output sample.</p>
+   <p>Each output sample of the <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item⑥">Sample Transform Derived Image Item</a> is obtained by evaluating an <a data-link-type="dfn" href="#sato-expression" id="ref-for-sato-expression">expression</a> consisting of a series of integer <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator①">operators</a> and <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand">operands</a>. An <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand①">operand</a> is a constant or a sample from an input image item located at the same channel index and at the same spatial coordinates as the output sample.</p>
    <p>No color space conversion, matrix coefficients, or transfer characteristics function shall be applied to the input samples. They are already in the same color space as the output samples.</p>
-   <p>The output reconstructed image is made up of the output samples, whose values shall each be clamped to fit in the number of bits per sample as defined by the <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①②②">pixi</a>'</code> property of the reconstructed image item. The <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②③">full_range_flag</a></code> field of the <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②④">colr</a>'</code> property of <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②⑤">colour_type</a></code> <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②⑥">nclx</a>'</code> also defines a range of values to clamp to, as defined in <a data-link-type="biblio" href="#biblio-cicp" title="H.273 : Coding-independent code points for video signal type identification">[CICP]</a>.</p>
-   <p class="note" role="note"><span class="marker">NOTE:</span> <a href="#sato-examples">Appendix A: (informative) Sample Transform Derived Image Item Examples</a> contains examples of Sample Transform Derived Image Item usage.</p>
+   <p>The output reconstructed image is made up of the output samples, whose values shall each be clamped to fit in the number of bits per sample as defined by the <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something①②②">PixelInformationProperty</a></code> of the reconstructed image item. The <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②③">full_range_flag</a></code> field of the <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②④">ColourInformationBox</a></code> property of <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②⑤">colour_type</a></code> <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②⑥">nclx</a>'</code> also defines a range of values to clamp to, as defined in <a data-link-type="biblio" href="#biblio-cicp" title="H.273 : Coding-independent code points for video signal type identification">[CICP]</a>.</p>
+   <p class="note" role="note"><span class="marker">NOTE:</span> <a href="#sato-examples">Appendix A: (informative) Sample Transform Derived Image Item Examples</a> contains examples of <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item⑦">Sample Transform Derived Image Item</a> usage.</p>
    <h5 class="no-toc heading settled" data-level="4.2.3.2" id="sample-transform-syntax"><span class="secno">4.2.3.2. </span><span class="content">Syntax</span><a class="self-link" href="#sample-transform-syntax"></a></h5>
-   <p>An expression is a series of <a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token">tokens</a>. A <a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token①">token</a> is an <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand②">operand</a> or an <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator②">operator</a>. An <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand③">operand</a> can be a literal constant value or a sample value. A stack is used to keep track of the results of the subexpressions. An <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator③">operator</a> takes either one or two input <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand④">operands</a>. Each unary <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator④">operator</a> pops one value from the stack. Each binary <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator⑤">operator</a> pops two values from the stack, the first being the right <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand⑤">operand</a> and the second being the left <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand⑥">operand</a>. Each <a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token②">token</a> results in a value pushed to the stack. The single remaining value in the stack after evaluating the whole expression is the resulting output sample.</p>
+   <p>An <dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-expression">expression</dfn> is a series of <a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token">tokens</a>. A <a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token①">token</a> is an <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand②">operand</a> or an <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator②">operator</a>. An <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand③">operand</a> can be a literal constant value or a sample value. A stack is used to keep track of the results of the <a data-link-type="dfn" href="#sato-expression" id="ref-for-sato-expression①">subexpressions</a>. An <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator③">operator</a> takes either one or two input <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand④">operands</a>. Each unary <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator④">operator</a> pops one value from the stack. Each binary <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator⑤">operator</a> pops two values from the stack, the first being the right <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand⑤">operand</a> and the second being the left <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand⑥">operand</a>. Each <a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token②">token</a> results in a value pushed to the stack. The single remaining value in the stack after evaluating the whole <a data-link-type="dfn" href="#sato-expression" id="ref-for-sato-expression②">expression</a> is the resulting output sample.</p>
 <pre class="language-c highlight"><c- n>aligned</c-><c- p>(</c-><c- mi>8</c-><c- p>)</c-> <c- n>class</c-> <c- n>SampleTransform</c-> <c- p>{</c->
     <c- b>unsigned</c-> <c- nf>int</c-><c- p>(</c-><c- mi>2</c-><c- p>)</c-> <c- n>version</c-> <c- o>=</c-> <c- mi>0</c-><c- p>;</c->
     <c- b>unsigned</c-> <c- nf>int</c-><c- p>(</c-><c- mi>4</c-><c- p>)</c-> <c- n>reserved</c-><c- p>;</c->
     <c- b>unsigned</c-> <c- nf>int</c-><c- p>(</c-><c- mi>2</c-><c- p>)</c-> <c- n>bit_depth</c-><c- p>;</c-> <c- c1>// Enum signaling signed 8, 16, 32 or 64-bit.</c->
+    <c- c1>// Create an empty stack of signed integer elements of that depth.</c->
     <c- b>unsigned</c-> <c- nf>int</c-><c- p>(</c-><c- mi>8</c-><c- p>)</c-> <c- n>token_count</c-><c- p>;</c->
     <c- k>for</c-> <c- p>(</c-><c- n>i</c-><c- o>=</c-><c- mi>0</c-><c- p>;</c-> <c- n>i</c-><c- o>&lt;</c-><c- n>token_count</c-><c- p>;</c-> <c- n>i</c-><c- o>++</c-><c- p>)</c-> <c- p>{</c->
         <c- b>unsigned</c-> <c- nf>int</c-><c- p>(</c-><c- mi>8</c-><c- p>)</c-> <c- n>token</c-><c- p>;</c->
@@ -2457,7 +2458,7 @@ <h5 class="no-toc heading settled" data-level="4.2.3.2" id="sample-transform-syn
 <c- p>}</c->
 </pre>
    <h5 class="no-toc heading settled" data-level="4.2.3.3" id="sample-transform-semantics"><span class="secno">4.2.3.3. </span><span class="content">Semantics</span><a class="self-link" href="#sample-transform-semantics"></a></h5>
-   <p><dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-version">version</dfn> shall be equal to 0. Readers shall ignore a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item⑦">Sample Transform Derived Image Item</a> with an unrecognized <code><a data-link-type="dfn" href="#sato-version" id="ref-for-sato-version">version</a></code> number.</p>
+   <p><dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-version">version</dfn> shall be equal to 0. Readers shall ignore a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item⑧">Sample Transform Derived Image Item</a> with an unrecognized <code><a data-link-type="dfn" href="#sato-version" id="ref-for-sato-version">version</a></code> number.</p>
    <p><dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-reserved">reserved</dfn> shall be equal to 0. The value of <code><a data-link-type="dfn" href="#sato-reserved" id="ref-for-sato-reserved">reserved</a></code> shall be ignored by readers.</p>
    <p><dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-bit_depth">bit_depth</dfn> determines the precision (from 8 to 64 bits, see <a href="#sato-num-bits-table">Table 1</a>) of the signed integer temporary variable supporting the intermediate results of the operations. It also determines the precision of the stack elements and the field size of the <code><a data-link-type="dfn" href="#sato-constant" id="ref-for-sato-constant①">constant</a></code> fields. This intermediate precision shall be high enough so that all input sample values fit into that signed bit depth.</p>
    <table class="data" id="sato-num-bits-table">
@@ -2465,7 +2466,7 @@ <h5 class="no-toc heading settled" data-level="4.2.3.3" id="sample-transform-sem
     <thead>
      <tr>
       <th>Value of <code><a data-link-type="dfn" href="#sato-bit_depth" id="ref-for-sato-bit_depth①">bit_depth</a></code>
-      <th>Intermediate bit depth (sign bit inclusive) <dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-num_bits">num_bits</dfn>
+      <th>Intermediate bit depth (sign bit inclusive) <code><dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-num_bits">num_bits</dfn></code>
     <tbody>
      <tr>
       <td>0
@@ -2482,7 +2483,7 @@ <h5 class="no-toc heading settled" data-level="4.2.3.3" id="sample-transform-sem
    </table>
    <p>The result of any computation underflowing or overflowing the intermediate bit depth is replaced by -2<sup><code><a data-link-type="dfn" href="#sato-num_bits" id="ref-for-sato-num_bits①">num_bits</a></code>-1</sup> and 2<sup><code><a data-link-type="dfn" href="#sato-num_bits" id="ref-for-sato-num_bits②">num_bits</a></code>-1</sup>-1, respectively. Encoder implementations should not create files leading to potential computation underflow or overflow. Decoder implementations shall check for computation underflow or overflow and clamp the results accordingly. Computations with <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand⑦">operands</a> of negative values use the two’s-complement representation.</p>
    <p><dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-token_count">token_count</dfn> is the expected number of <a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token③">tokens</a> to read. <span id="assert-66976029">The value of <code><a data-link-type="dfn" href="#sato-token_count" id="ref-for-sato-token_count">token_count</a></code> shall be greater than 0.</span></p>
-   <p><dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-token">token</dfn> determines the type of the <dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-operand">operand</dfn> (<code><a data-link-type="dfn" href="#sato-constant" id="ref-for-sato-constant②">constant</a></code> or input image item sample) or the <dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-operator">operator</dfn> (how to transform one or two <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand⑧">operands</a> into the result). See <a href="#sato-token-table">Table 2</a>. Readers shall ignore a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item⑧">Sample Transform Derived Image Item</a> with a reserved <code><a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token④">token</a></code> value.</p>
+   <p><dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-token">token</dfn> determines the type of the <dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-operand">operand</dfn> (<code><a data-link-type="dfn" href="#sato-constant" id="ref-for-sato-constant②">constant</a></code> or input image item sample) or the <dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-operator">operator</dfn> (how to transform one or two <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand⑧">operands</a> into the result). See <a href="#sato-token-table">Table 2</a>. Readers shall ignore a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item⑨">Sample Transform Derived Image Item</a> with a reserved <code><a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token④">token</a></code> value.</p>
    <table class="data" id="sato-token-table">
     <caption style="caption-side:bottom"> Table 2 - Meaning of the value of <code><a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token⑤">token</a></code>. </caption>
     <thead>
@@ -2793,9 +2794,9 @@ <h5 class="no-toc heading settled" data-level="4.2.3.3" id="sample-transform-sem
    </table>
    <p><dfn class="dfn-paneled" data-dfn-for="sato" data-dfn-type="dfn" data-noexport id="sato-constant">constant</dfn> is a literal signed value extracted from the stream with a precision of <a data-link-type="dfn" href="#sato-intermediate-bit-depth" id="ref-for-sato-intermediate-bit-depth">intermediate bit depth</a>, pushed to the stack.</p>
    <h5 class="no-toc heading settled" data-level="4.2.3.4" id="sample-transform-constraints"><span class="secno">4.2.3.4. </span><span class="content">Constraints</span><a class="self-link" href="#sample-transform-constraints"></a></h5>
-   <p><a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item⑨">Sample Transform Derived Image Items</a> use the postfix notation to evaluate the result of the whole expression for each reconstructed image item sample.</p>
+   <p><a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⓪">Sample Transform Derived Image Items</a> use the postfix notation to evaluate the result of the whole <a data-link-type="dfn" href="#sato-expression" id="ref-for-sato-expression③">expression</a> for each reconstructed image item sample.</p>
    <ul>
-    <li data-md><span id="assert-73397869">The <a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token⑨">tokens</a> shall be evaluated in the order they are defined in the metadata (the <code><dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="sampletransform">SampleTransform</dfn></code> structure) of the <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⓪">Sample Transform Derived Image Item</a>.</span> 
+    <li data-md><span id="assert-989adc85">The <a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token⑨">tokens</a> shall be evaluated in the order they are defined in the metadata (the <code><dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="sampletransform">SampleTransform</dfn></code> structure defined in <a href="#sample-transform-syntax">§ 4.2.3.2 Syntax</a>) of the <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①①">Sample Transform Derived Image Item</a>.</span> 
     <li data-md><span id="assert-1f569fa5"><code><a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token①⓪">token</a></code> shall be at most <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②⑦">reference_count</a></code> when evaluating a sample <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand③⑤">operand</a> (when <math><mn>1</mn><mo>≤</mo><mi>token</mi><mo>≤</mo><mn>32</mn></math>).</span> 
     <li data-md><span id="assert-6c16d91f">There shall be at least one <code><a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token①①">token</a></code>.</span> 
     <li data-md>
@@ -2804,9 +2805,9 @@ <h5 class="no-toc heading settled" data-level="4.2.3.4" id="sample-transform-con
     <li data-md><span id="assert-75c5cbbc">There shall be at least 2 elements in the stack before evaluating a binary <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator②②">operator</a>.</span> 
     <li data-md><span id="assert-bac41e3a">There shall be exactly one remaining element in the stack after evaluating the last <code><a data-link-type="dfn" href="#sato-token" id="ref-for-sato-token①③">token</a></code>.</span> This element is the value of the reconstructed image item sample. 
    </ul>
-   <p>Non-compliant expressions shall be rejected by parsers as invalid files.</p>
+   <p>Non-compliant <a data-link-type="dfn" href="#sato-expression" id="ref-for-sato-expression④">expressions</a> shall be rejected by parsers as invalid files.</p>
    <p class="note" role="note">
-    <span class="marker">Note:</span> Because each <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator②③">operator</a> pops one or two elements and then pushes one element to the stack, there is at most one more <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand③⑥">operand</a> than <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator②④">operators</a> in the expression. There are at least 
+    <span class="marker">Note:</span> Because each <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator②③">operator</a> pops one or two elements and then pushes one element to the stack, there is at most one more <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand③⑥">operand</a> than <a data-link-type="dfn" href="#sato-operator" id="ref-for-sato-operator②④">operators</a> in the <a data-link-type="dfn" href="#sato-expression" id="ref-for-sato-expression⑤">expression</a>. There are at least 
     <math>
      <mo>floor</mo>
      <mo>(</mo>
@@ -2826,7 +2827,7 @@ <h5 class="no-toc heading settled" data-level="4.2.3.4" id="sample-transform-con
      </mfrac>
      <mo>)</mo>
     </math>
-     <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand③⑦">operands</a>. <code><a data-link-type="dfn" href="#sato-token_count" id="ref-for-sato-token_count②">token_count</a></code> is at most 255, meaning the maximum stack size for a valid expression is 128.
+     <a data-link-type="dfn" href="#sato-operand" id="ref-for-sato-operand③⑦">operands</a>. <code><a data-link-type="dfn" href="#sato-token_count" id="ref-for-sato-token_count②">token_count</a></code> is at most 255, meaning the maximum stack size for a valid <a data-link-type="dfn" href="#sato-expression" id="ref-for-sato-expression⑥">expression</a> is 128.
    </p>
    <h2 class="heading settled" data-level="5" id="groups"><span class="secno">5. </span><span class="content">Entity groups</span><a class="self-link" href="#groups"></a></h2>
    <p>The <code><a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②⑧">GroupsListBox</a></code> (<code>'<a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something①②⑨">grpl</a>'</code>) defined in <a data-link-type="biblio" href="#biblio-isobmff" title="Information technology — Coding of audio-visual objects — Part 12: ISO base media file format">[ISOBMFF]</a> may be used to group multiple image items or tracks in a file together. The type of the group describes how the image items or tracks are related. <span id="assert-988bf23f">Decoders should ignore groups of unknown type.</span></p>
@@ -3329,19 +3330,19 @@ <h2 class="heading settled" data-level="11" id="change-list"><span class="secno"
      <p><a href="https://github.com/AOMediaCodec/av1-avif/pull/256">Clean up linking to base specs and duplicated information</a></p>
    </ul>
    <h2 class="heading settled" id="sato-examples"><span class="content">Appendix A: (informative) Sample Transform Derived Image Item Examples</span><a class="self-link" href="#sato-examples"></a></h2>
-   <p>This informative appendix contains example recipes for extending base <a data-link-type="dfn" href="#avif" id="ref-for-avif①⑤">AVIF</a> features with <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①①">Sample Transform Derived Image Items</a>.</p>
+   <p>This informative appendix contains example recipes for extending base <a data-link-type="dfn" href="#avif" id="ref-for-avif①⑤">AVIF</a> features with <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①②">Sample Transform Derived Image Items</a>.</p>
    <h3 class="heading settled" id="sato-example-bit-depth-extension"><span class="content">Bit depth extension</span><a class="self-link" href="#sato-example-bit-depth-extension"></a></h3>
-   <p><a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①②">Sample Transform Derived Image Items</a> allow for more than 12 bits per channel per sample by combining several <a data-link-type="dfn" href="#av1-image-item" id="ref-for-av1-image-item②⑤">AV1 image items</a> in multiple ways.</p>
+   <p><a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①③">Sample Transform Derived Image Items</a> allow for more than 12 bits per channel per sample by combining several <a data-link-type="dfn" href="#av1-image-item" id="ref-for-av1-image-item②⑤">AV1 image items</a> in multiple ways.</p>
    <h4 class="heading settled" id="sato-example-suffix-bit-depth-extension"><span class="content">Suffix bit depth extension</span><a class="self-link" href="#sato-example-suffix-bit-depth-extension"></a></h4>
-   <p>The following example describes how to leverage a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①③">Sample Transform Derived Image Item</a> on top of a regular 8-bit <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑥②">MIAF image item</a> to extend the decoded bit depth to 16 bits.</p>
+   <p>The following example describes how to leverage a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①④">Sample Transform Derived Image Item</a> on top of a regular 8-bit <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑥②">MIAF image item</a> to extend the decoded bit depth to 16 bits.</p>
    <p>Consider the following:</p>
    <ul>
     <li data-md>
-     <p>A <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑥③">MIAF image item</a> being a losslessly coded image item,<br>and its <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑥④">pixi</a>'</code> property with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑥⑤">bits_per_channel</a></code>=8,</p>
+     <p>A <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑥③">MIAF image item</a> being a losslessly coded image item,<br>and its <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑥④">PixelInformationProperty</a></code> with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑥⑤">bits_per_channel</a></code>=8,</p>
     <li data-md>
-     <p>Another <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑥⑥">MIAF image item</a> being a lossily or losslessly coded image item with the same dimensions and number of samples as the first input image item,<br>and its <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑥⑦">pixi</a>'</code> property with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑥⑧">bits_per_channel</a></code>=8,</p>
+     <p>Another <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑥⑥">MIAF image item</a> being a lossily or losslessly coded image item with the same dimensions and number of samples as the first input image item,<br>and its <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑥⑦">PixelInformationProperty</a></code> with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑥⑧">bits_per_channel</a></code>=8,</p>
     <li data-md>
-     <p>A <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①④">Sample Transform Derived Image Item</a> with the two items above as input in this order,<br>and its <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑥⑨">pixi</a>'</code> property with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑦⓪">bits_per_channel</a></code>=16,<br>and the following <code><a data-link-type="dfn" href="#sampletransform" id="ref-for-sampletransform">SampleTransform</a></code> fields:</p>
+     <p>A <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⑤">Sample Transform Derived Image Item</a> with the two items above as input in this order,<br>and its <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑥⑨">PixelInformationProperty</a></code> with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑦⓪">bits_per_channel</a></code>=16,<br>and the following <code><a data-link-type="dfn" href="#sampletransform" id="ref-for-sampletransform">SampleTransform</a></code> fields:</p>
      <ul>
       <li data-md>
        <p><code><a data-link-type="dfn" href="#sato-version" id="ref-for-sato-version①">version</a></code>=0</p>
@@ -3406,17 +3407,17 @@ <h4 class="heading settled" id="sato-example-suffix-bit-depth-extension"><span c
     </msub>
    </math>
    <p>Each output sample is equal to the sum of a sample of the first input image item shifted to the left by 8 and of a sample of the second input image item. This can be viewed as a bit depth extension of the first input image item by the second input image item. The first input image item contains the 8 most significant bits and the second input image item contains the 8 least significant bits of the output reconstructed image item which has a bit depth of 16, something that is impossible to achieve with a single <a data-link-type="dfn" href="#av1-image-item" id="ref-for-av1-image-item②⑥">AV1 image item</a>.</p>
-   <p class="note" role="note"><span class="marker">NOTE:</span> If the first input image item is the <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑦①">primary image item</a> and is enclosed in an <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something②⑦②">altr</a>'</code> group (see <a href="#altr-group">§ 5.1 'altr' group</a>) with the <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⑤">Sample Transform Derived Image Item</a>, the first input image item is also a backward-compatible 8-bit regular coded image item that can be used by readers that do not support <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⑥">Sample Transform Derived Image Items</a> or do not need extra precision.</p>
+   <p class="note" role="note"><span class="marker">NOTE:</span> If the first input image item is the <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑦①">primary image item</a> and is enclosed in an <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something②⑦②">altr</a>'</code> group (see <a href="#altr-group">§ 5.1 'altr' group</a>) with the <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⑥">Sample Transform Derived Image Item</a>, the first input image item is also a backward-compatible 8-bit regular coded image item that can be used by readers that do not support <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⑦">Sample Transform Derived Image Items</a> or do not need extra precision.</p>
    <p class="note" role="note"><span class="marker">NOTE:</span> The second input image item loses its meaning of least significant part if any of the most significant bits changes, so the first input image item has to be losslessly encoded. The second input image item supports reasonable loss during encoding.</p>
    <p class="note" role="note"><span class="marker">NOTE:</span> This pattern can be used for reconstructed bit depths beyond 16 by combining more than two input image items or with various input bit depth configurations and operations.</p>
    <h4 class="heading settled" id="sato-example-residual-bit-depth-extension"><span class="content">Residual bit depth extension</span><a class="self-link" href="#sato-example-residual-bit-depth-extension"></a></h4>
-   <p>The following example describes how to leverage a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⑦">Sample Transform Derived Image Item</a> on top of a regular 12-bit <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑦③">MIAF image item</a> to extend the decoded bit depth to 16 bits.<br> It differs from the <a href="#sato-example-suffix-bit-depth-extension">Suffix bit depth extension</a> by its slightly longer series of operations allowing its first input image item to be lossily encoded.</p>
+   <p>The following example describes how to leverage a <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⑧">Sample Transform Derived Image Item</a> on top of a regular 12-bit <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑦③">MIAF image item</a> to extend the decoded bit depth to 16 bits.<br> It differs from the <a href="#sato-example-suffix-bit-depth-extension">Suffix bit depth extension</a> by its slightly longer series of operations allowing its first input image item to be lossily encoded.</p>
    <p>Consider the following:</p>
    <ul>
     <li data-md>
-     <p>A <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑦④">MIAF image item</a> being a lossily coded image item,<br>and its <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑦⑤">pixi</a>'</code> property with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑦⑥">bits_per_channel</a></code>=12,</p>
+     <p>A <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑦④">MIAF image item</a> being a lossily coded image item,<br>and its <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑦⑤">PixelInformationProperty</a></code> with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑦⑥">bits_per_channel</a></code>=12,</p>
     <li data-md>
-     <p>Another <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑦⑦">MIAF image item</a> being a lossily or losslessly coded image item with the same dimensions and number of samples as the first input image item,<br>and its <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑦⑧">pixi</a>'</code> property with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑦⑨">bits_per_channel</a></code>=8,<br>with the following contraints:</p>
+     <p>Another <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑦⑦">MIAF image item</a> being a lossily or losslessly coded image item with the same dimensions and number of samples as the first input image item,<br>and its <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑦⑧">PixelInformationProperty</a></code> with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑦⑨">bits_per_channel</a></code>=8,<br>with the following contraints:</p>
     <li style="list-style: none">
      <ul>
       <li style="list-style: none">
@@ -3551,10 +3552,10 @@ <h4 class="heading settled" id="sato-example-residual-bit-depth-extension"><span
        </msup>
       </math>
       <br>
-      <p class="note" role="note"><span class="marker">NOTE:</span> Files that do not respect this constraint will still decode successfully because Clause <a href="#sample-transform-definition">§ 4.2.3.1 Definition</a> mandates the resulting values to be each clamped to fit in the number of bits per sample as defined by the <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑧⓪">pixi</a>'</code> property of the reconstructed image item.</p>
+      <p class="note" role="note"><span class="marker">NOTE:</span> Files that do not respect this constraint will still decode successfully because Clause <a href="#sample-transform-definition">§ 4.2.3.1 Definition</a> mandates the resulting values to be each clamped to fit in the number of bits per sample as defined by the <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑧⓪">PixelInformationProperty</a></code> of the reconstructed image item.</p>
     </ul>
     <li data-md>
-     <p>A <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⑧">Sample Transform Derived Image Item</a> with the two items above as input in this order,<br>and its <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑧①">pixi</a>'</code> property with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑧②">bits_per_channel</a></code>=16,<br>and the following <code><a data-link-type="dfn" href="#sampletransform" id="ref-for-sampletransform①">SampleTransform</a></code> fields:</p>
+     <p>A <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⑨">Sample Transform Derived Image Item</a> with the two items above as input in this order,<br>and its <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑧①">PixelInformationProperty</a></code> with <code><a data-link-type="dfn" href="https://www.iso.org/standard/66067.html" id="ref-for-something②⑧②">bits_per_channel</a></code>=16,<br>and the following <code><a data-link-type="dfn" href="#sampletransform" id="ref-for-sampletransform①">SampleTransform</a></code> fields:</p>
      <ul>
       <li data-md>
        <p><code><a data-link-type="dfn" href="#sato-version" id="ref-for-sato-version②">version</a></code>=0</p>
@@ -3630,7 +3631,7 @@ <h4 class="heading settled" id="sato-example-residual-bit-depth-extension"><span
     <mn>128</mn>
    </math>
    <p>Each output sample is equal to the sum of a sample of the first input image item shifted to the left by 4 and of a sample of the second input image item offset by -128. This can be viewed as a bit depth extension of the first input image item by the second input image item which contains the residuals to correct the precision loss of the first input image item.</p>
-   <p class="note" role="note"><span class="marker">NOTE:</span> If the first input image item is the <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑧③">primary image item</a> and is enclosed in an <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something②⑧④">altr</a>'</code> group (see <a href="#altr-group">§ 5.1 'altr' group</a>) with the derived image item, the first input image item is also a backward-compatible 12-bit regular coded image item that can be used by decoding contexts that do not support <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item①⑨">Sample Transform Derived Image Items</a> or do not need extra precision.</p>
+   <p class="note" role="note"><span class="marker">NOTE:</span> If the first input image item is the <a data-link-type="dfn" href="https://www.iso.org/standard/74417.html" id="ref-for-something②⑧③">primary image item</a> and is enclosed in an <code>'<a data-link-type="dfn" href="https://www.iso.org/standard/68960.html" id="ref-for-something②⑧④">altr</a>'</code> group (see <a href="#altr-group">§ 5.1 'altr' group</a>) with the derived image item, the first input image item is also a backward-compatible 12-bit regular coded image item that can be used by decoding contexts that do not support <a data-link-type="dfn" href="#sample-transform-derived-image-item" id="ref-for-sample-transform-derived-image-item②⓪">Sample Transform Derived Image Items</a> or do not need extra precision.</p>
    <p class="note" role="note"><span class="marker">NOTE:</span> The first input image item supports reasonable loss during encoding because the second input image item "overlaps" by 4 bits to correct the loss. The second input image item supports reasonable loss during encoding.</p>
    <p class="note" role="note"><span class="marker">NOTE:</span> This pattern can be used for reconstructed bit depths beyond 16 by combining more than two input image items or with various input bit depth configurations and operations.</p>
   </main>
@@ -3808,6 +3809,7 @@ <h3 class="no-num no-ref heading settled" id="index-defined-here"><span class="c
    <li><a href="#avif-image-sequence-brand-avis">avis</a><span>, in § 6.3</span>
    <li><a href="#sato-bit_depth">bit_depth</a><span>, in § 4.2.3.3</span>
    <li><a href="#sato-constant">constant</a><span>, in § 4.2.3.3</span>
+   <li><a href="#sato-expression">expression</a><span>, in § 4.2.3.2</span>
    <li><a href="#grid-derived-image-item">grid derived image item</a><span>, in § 4.2.1</span>
    <li><a href="#sato-intermediate-bit-depth">intermediate bit depth</a><span>, in § 4.2.3.3</span>
    <li><a href="#layer_size">layer_size</a><span>, in § 2.3.2.3.4</span>
@@ -4393,8 +4395,7 @@ <h3 class="no-num no-ref heading settled" id="normative"><span class="content">N
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@@ -4406,7 +4407,8 @@ <h3 class="no-num no-ref heading settled" id="normative"><span class="content">N
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