Fixing lossless slider for webP. Previously you couldn't select "9" :D (#236)

* MozJPEG chroma subsampling and quality (#235)

* Adding chroma subsampling for mozjpeg

* Adding separate chroma quality.

* Preact sometimes removes the inline styles, this fixes it.

* Simplifying chroma subsample

* Adding comments

* Fixing lossless slider for webP. Previously you couldn't select "9" :D

* Destructuring args.

codecs/mozjpeg_enc/README.md

@@ -39,5 +39,9 @@ struct MozJpegOptions {
   bool trellis_opt_zero;
   bool trellis_opt_table;
   int trellis_loops;
+  bool auto_subsample;
+  int chroma_subsample;
+  bool separate_chroma_quality;
+  int chroma_quality;
 };
 ```

codecs/mozjpeg_enc/example.html

@@ -21,7 +21,7 @@
     console.log('Version:', module.version().toString(16));
     const image = await loadImage('../example.png');
     const result = module.encode(image.data, image.width, image.height, {
-      quality: 40,
+      quality: 75,
       baseline: false,
       arithmetic: false,
       progressive: true,
@@ -29,10 +29,14 @@
       smoothing: 0,
       color_space: 3,
       quant_table: 3,
-      trellis_multipass: true,
-      trellis_opt_zero: true,
-      trellis_opt_table: true,
+      trellis_multipass: false,
+      trellis_opt_zero: false,
+      trellis_opt_table: false,
       trellis_loops: 1,
+      auto_subsample: true,
+      chroma_subsample: 2,
+      separate_chroma_quality: false,
+      chroma_quality: 75,
     });
 
     const blob = new Blob([result], {type: 'image/jpeg'});

codecs/mozjpeg_enc/mozjpeg_enc.cpp

@@ -29,6 +29,10 @@ struct MozJpegOptions {
   bool trellis_opt_zero;
   bool trellis_opt_table;
   int trellis_loops;
+  bool auto_subsample;
+  int chroma_subsample;
+  bool separate_chroma_quality;
+  int chroma_quality;
 };
 
 int version() {
@@ -119,9 +123,6 @@ val encode(std::string image_in, int image_width, int image_height, MozJpegOptio
    */
   jpeg_set_defaults(&cinfo);
 
-  /* Now you can set any non-default parameters you wish to.
-   * Here we just illustrate the use of quality (quantization table) scaling:
-   */
   jpeg_set_colorspace(&cinfo, (J_COLOR_SPACE) opts.color_space);
 
   if (opts.quant_table != -1) {
@@ -142,11 +143,23 @@ val encode(std::string image_in, int image_width, int image_height, MozJpegOptio
   jpeg_c_set_bool_param(&cinfo, JBOOLEAN_TRELLIS_Q_OPT, opts.trellis_opt_table);
   jpeg_c_set_int_param(&cinfo, JINT_TRELLIS_NUM_LOOPS, opts.trellis_loops);
 
+  // A little hacky to build a string for this, but it means we can use set_quality_ratings which
+  // does some useful heuristic stuff.
   std::string quality_str = std::to_string(opts.quality);
+
+  if (opts.separate_chroma_quality && opts.color_space == JCS_YCbCr) {
+    quality_str += "," + std::to_string(opts.chroma_quality);
+  }
+
   char const *pqual = quality_str.c_str();
 
   set_quality_ratings(&cinfo, (char*) pqual, opts.baseline);
 
+  if (!opts.auto_subsample && opts.color_space == JCS_YCbCr) {
+    cinfo.comp_info[0].h_samp_factor = opts.chroma_subsample;
+    cinfo.comp_info[0].v_samp_factor = opts.chroma_subsample;
+  }
+
   if (!opts.baseline && opts.progressive) {
     jpeg_simple_progression(&cinfo);
   } else {
@@ -209,6 +222,10 @@ EMSCRIPTEN_BINDINGS(my_module) {
     .field("trellis_opt_zero", &MozJpegOptions::trellis_opt_zero)
     .field("trellis_opt_table", &MozJpegOptions::trellis_opt_table)
     .field("trellis_loops", &MozJpegOptions::trellis_loops)
+    .field("chroma_subsample", &MozJpegOptions::chroma_subsample)
+    .field("auto_subsample", &MozJpegOptions::auto_subsample)
+    .field("separate_chroma_quality", &MozJpegOptions::separate_chroma_quality)
+    .field("chroma_quality", &MozJpegOptions::chroma_quality)
     ;
 
   function("version", &version);

src/codecs/mozjpeg/encoder-meta.ts

@@ -17,6 +17,10 @@ export interface EncodeOptions {
   trellis_opt_zero: boolean;
   trellis_opt_table: boolean;
   trellis_loops: number;
+  auto_subsample: boolean;
+  chroma_subsample: number;
+  separate_chroma_quality: boolean;
+  chroma_quality: number;
 }
 
 export interface EncoderState { type: typeof type; options: EncodeOptions; }
@@ -38,4 +42,8 @@ export const defaultOptions: EncodeOptions = {
   trellis_opt_zero: false,
   trellis_opt_table: false,
   trellis_loops: 1,
+  auto_subsample: true,
+  chroma_subsample: 2,
+  separate_chroma_quality: false,
+  chroma_quality: 75,
 };

src/codecs/mozjpeg/options.tsx

@@ -39,8 +39,13 @@ export default class MozJPEGEncoderOptions extends Component<Props, State> {
       trellis_multipass: inputFieldChecked(form.trellis_multipass, options.trellis_multipass),
       trellis_opt_zero: inputFieldChecked(form.trellis_opt_zero, options.trellis_opt_zero),
       trellis_opt_table: inputFieldChecked(form.trellis_opt_table, options.trellis_opt_table),
+      auto_subsample: inputFieldChecked(form.auto_subsample, options.auto_subsample),
+      separate_chroma_quality:
+        inputFieldChecked(form.separate_chroma_quality, options.separate_chroma_quality),
       // .value
       quality: inputFieldValueAsNumber(form.quality, options.quality),
+      chroma_quality: inputFieldValueAsNumber(form.chroma_quality, options.chroma_quality),
+      chroma_subsample: inputFieldValueAsNumber(form.chroma_subsample, options.chroma_subsample),
       smoothing: inputFieldValueAsNumber(form.smoothing, options.smoothing),
       color_space: inputFieldValueAsNumber(form.color_space, options.color_space),
       quant_table: inputFieldValueAsNumber(form.quant_table, options.quant_table),
@@ -75,6 +80,72 @@ export default class MozJPEGEncoderOptions extends Component<Props, State> {
         <Expander>
           {showAdvanced ?
             <div>
+              <label class={style.optionTextFirst}>
+                Channels:
+                <Select
+                  name="color_space"
+                  value={options.color_space}
+                  onChange={this.onChange}
+                >
+                  <option value={MozJpegColorSpace.GRAYSCALE}>Grayscale</option>
+                  <option value={MozJpegColorSpace.RGB}>RGB</option>
+                  <option value={MozJpegColorSpace.YCbCr}>YCbCr</option>
+                </Select>
+              </label>
+              <Expander>
+                {options.color_space === MozJpegColorSpace.YCbCr ?
+                  <div>
+                    <label class={style.optionInputFirst}>
+                      <Checkbox
+                        name="auto_subsample"
+                        checked={options.auto_subsample}
+                        onChange={this.onChange}
+                      />
+                      Auto subsample chroma
+                    </label>
+                    <Expander>
+                      {options.auto_subsample ? null :
+                        <div class={style.optionOneCell}>
+                          <Range
+                            name="chroma_subsample"
+                            min="1"
+                            max="4"
+                            value={options.chroma_subsample}
+                            onInput={this.onChange}
+                          >
+                            Subsample chroma by:
+                          </Range>
+                        </div>
+                      }
+                    </Expander>
+                    <label class={style.optionInputFirst}>
+                      <Checkbox
+                        name="separate_chroma_quality"
+                        checked={options.separate_chroma_quality}
+                        onChange={this.onChange}
+                      />
+                      Separate chroma quality
+                    </label>
+                    <Expander>
+                      {options.separate_chroma_quality ?
+                        <div class={style.optionOneCell}>
+                          <Range
+                            name="chroma_quality"
+                            min="0"
+                            max="100"
+                            value={options.chroma_quality}
+                            onInput={this.onChange}
+                          >
+                            Chroma quality:
+                          </Range>
+                        </div>
+                        : null
+                      }
+                    </Expander>
+                  </div>
+                  : null
+                }
+              </Expander>
               <label class={style.optionInputFirst}>
                 <Checkbox
                   name="baseline"
@@ -119,18 +190,6 @@ export default class MozJPEGEncoderOptions extends Component<Props, State> {
                   Smoothing:
                 </Range>
               </div>
-              <label class={style.optionTextFirst}>
-                Channels:
-                <Select
-                  name="color_space"
-                  value={options.color_space}
-                  onChange={this.onChange}
-                >
-                  <option value={MozJpegColorSpace.GRAYSCALE}>Grayscale</option>
-                  <option value={MozJpegColorSpace.RGB}>RGB</option>
-                  <option value={MozJpegColorSpace.YCbCr}>YCbCr</option>
-                </Select>
-              </label>
               <label class={style.optionTextFirst}>
                 Quantization:
                 <Select

src/codecs/webp/options.tsx

@@ -26,8 +26,10 @@ const losslessPresets:[number, number][] = [
 ];
 const losslessPresetDefault = 6;
 
-function determineLosslessQuality(quality: number): number {
-  const index = losslessPresets.findIndex(item => item[1] === quality);
+function determineLosslessQuality(quality: number, method: number): number {
+  const index = losslessPresets.findIndex(
+    ([presetMethod, presetQuality]) => presetMethod === method && presetQuality === quality,
+  );
   if (index !== -1) return index;
   // Quality doesn't match one of the presets.
   // This can happen when toggling 'lossless'.
@@ -45,7 +47,7 @@ export default class WebPEncoderOptions extends Component<Props, State> {
     const lossless = inputFieldCheckedAsNumber(form.lossless);
     const { options } = this.props;
     const losslessPresetValue = inputFieldValueAsNumber(
-      form.lossless_preset, determineLosslessQuality(options.quality),
+      form.lossless_preset, determineLosslessQuality(options.quality, options.method),
     );
 
     const newOptions: EncodeOptions = {
@@ -97,7 +99,7 @@ export default class WebPEncoderOptions extends Component<Props, State> {
             name="lossless_preset"
             min="0"
             max="9"
-            value={determineLosslessQuality(options.quality)}
+            value={determineLosslessQuality(options.quality, options.method)}
             onInput={this.onChange}
           >
             Effort:

src/components/App/index.tsx

@@ -4,7 +4,7 @@ import { bind, linkRef, Fileish } from '../../lib/initial-util';
 import * as style from './style.scss';
 import { FileDropEvent } from './custom-els/FileDrop';
 import './custom-els/FileDrop';
-import SnackBarElement from '../../lib/SnackBar';
+import SnackBarElement, { SnackOptions } from '../../lib/SnackBar';
 import '../../lib/SnackBar';
 import Intro from '../intro';
 import '../custom-els/LoadingSpinner';
@@ -39,7 +39,7 @@ export default class App extends Component<Props, State> {
     import('../compress').then((module) => {
       this.setState({ Compress: module.default });
     }).catch(() => {
-      this.showError('Failed to load app');
+      this.showSnack('Failed to load app');
     });
 
     // In development, persist application state across hot reloads:
@@ -66,9 +66,9 @@ export default class App extends Component<Props, State> {
   }
 
   @bind
-  private showError(error: string) {
+  private showSnack(message: string, options: SnackOptions = {}): Promise<string> {
     if (!this.snackbar) throw Error('Snackbar missing');
-    this.snackbar.showSnackbar({ message: error });
+    return this.snackbar.showSnackbar(message, options);
   }
 
   render({}: Props, { file, Compress }: State) {
@@ -76,9 +76,9 @@ export default class App extends Component<Props, State> {
       <div id="app" class={style.app}>
         <file-drop accept="image/*" onfiledrop={this.onFileDrop} class={style.drop}>
           {(!file)
-            ? <Intro onFile={this.onIntroPickFile} onError={this.showError} />
+            ? <Intro onFile={this.onIntroPickFile} showSnack={this.showSnack} />
             : (Compress)
-              ? <Compress file={file} onError={this.showError} />
+              ? <Compress file={file} showSnack={this.showSnack} />
               : <loading-spinner class={style.appLoader}/>
           }
           <snack-bar ref={linkRef(this, 'snackbar')} />

src/components/compress/index.tsx

@@ -35,6 +35,7 @@ import { VectorResizeOptions, BitmapResizeOptions } from '../../codecs/resize/pr
 import './custom-els/MultiPanel';
 import Results from '../results';
 import { ExpandIcon, CopyAcrossIconProps } from '../../lib/icons';
+import SnackBarElement from 'src/lib/SnackBar';
 
 export interface SourceImage {
   file: File | Fileish;
@@ -58,7 +59,7 @@ interface EncodedImage {
 
 interface Props {
   file: File | Fileish;
-  onError: (msg: string) => void;
+  showSnack: SnackBarElement['showSnackbar'];
 }
 
 interface State {
@@ -250,12 +251,24 @@ export default class Compress extends Component<Props, State> {
     }
   }
 
-  private onCopyToOtherClick(index: 0 | 1) {
+  private async onCopyToOtherClick(index: 0 | 1) {
     const otherIndex = (index + 1) % 2;
+    const oldSettings = this.state.images[otherIndex];
 
     this.setState({
       images: cleanSet(this.state.images, otherIndex, this.state.images[index]),
     });
+
+    const result = await this.props.showSnack('Settings copied across', {
+      timeout: 5000,
+      actions: ['undo', 'dismiss'],
+    });
+
+    if (result !== 'undo') return;
+
+    this.setState({
+      images: cleanSet(this.state.images, otherIndex, oldSettings),
+    });
   }
 
   @bind
@@ -318,7 +331,7 @@ export default class Compress extends Component<Props, State> {
       console.error(err);
       // Another file has been opened before this one processed.
       if (this.state.loadingCounter !== loadingCounter) return;
-      this.props.onError('Invalid image');
+      this.props.showSnack('Invalid image');
       this.setState({ loading: false });
     }
   }
@@ -377,7 +390,7 @@ export default class Compress extends Component<Props, State> {
         }
       } catch (err) {
         if (err.name === 'AbortError') return;
-        this.props.onError(`Processing error (type=${image.encoderState.type}): ${err}`);
+        this.props.showSnack(`Processing error (type=${image.encoderState.type}): ${err}`);
         throw err;
       }
     }

src/components/intro/index.tsx

@@ -12,6 +12,7 @@ import artworkIcon from './imgs/demos/artwork-icon.jpg';
 import deviceScreenIcon from './imgs/demos/device-screen-icon.jpg';
 import logoIcon from './imgs/demos/logo-icon.png';
 import * as style from './style.scss';
+import SnackBarElement from '../../lib/SnackBar';
 
 const demos = [
   {
@@ -42,7 +43,7 @@ const demos = [
 
 interface Props {
   onFile: (file: File | Fileish) => void;
-  onError: (error: string) => void;
+  showSnack: SnackBarElement['showSnackbar'];
 }
 interface State {
   fetchingDemoIndex?: number;
@@ -79,7 +80,7 @@ export default class Intro extends Component<Props, State> {
       this.props.onFile(file);
     } catch (err) {
       this.setState({ fetchingDemoIndex: undefined });
-      this.props.onError("Couldn't fetch demo image");
+      this.props.showSnack("Couldn't fetch demo image");
     }
   }
 

src/custom-els/RangeInput/index.ts

@@ -57,6 +57,8 @@ class RangeInputElement extends HTMLElement {
 
     this.insertBefore(this._input, this.firstChild);
     this._valueDisplay = this.querySelector('.' + style.valueDisplay) as HTMLDivElement;
+    // Set inline styles (this is useful when used with frameworks which might clear inline styles)
+    this._update();
   }
 
   get labelPrecision(): string {

src/lib/SnackBar/index.ts

@@ -1,114 +1,96 @@
-import './styles.css';
-
-const DEFAULT_TIMEOUT = 2750;
+import * as style from './styles.css';
 
 export interface SnackOptions {
-  message: string;
   timeout?: number;
-  actionText?: string;
-  actionHandler?: () => boolean | null;
+  actions?: string[];
 }
 
-export interface SnackShowResult {
-  action: boolean;
-}
+function createSnack(message: string, options: SnackOptions): [Element, Promise<string>] {
+  const {
+    timeout = 0,
+    actions = [],
+  } = options;
 
-class Snack {
-  private _onremove: ((result: SnackShowResult) => void)[] = [];
-  private _options: SnackOptions;
-  private _element: Element = document.createElement('div');
-  private _text: Element = document.createElement('div');
-  private _button: Element = document.createElement('button');
-  private _showing = false;
-  private _closeTimer?: number;
-  private _result: SnackShowResult = {
-    action: false,
-  };
+  // Provide a default 'dismiss' action
+  if (!timeout && actions.length === 0) actions.push('dismiss');
 
-  constructor (options: SnackOptions, callback?: (result: SnackShowResult) => void) {
-    this._options = options;
+  const el = document.createElement('div');
+  el.className = style.snackbar;
+  el.setAttribute('aria-live', 'assertive');
+  el.setAttribute('aria-atomic', 'true');
+  el.setAttribute('aria-hidden', 'false');
 
-    this._element.className = 'snackbar';
-    this._element.setAttribute('aria-live', 'assertive');
-    this._element.setAttribute('aria-atomic', 'true');
-    this._element.setAttribute('aria-hidden', 'true');
+  const text = document.createElement('div');
+  text.className = style.text;
+  text.textContent = message;
+  el.appendChild(text);
 
-    this._text.className = 'snackbar--text';
-    this._text.textContent = options.message;
-    this._element.appendChild(this._text);
+  const result = new Promise<string>((resolve) => {
+    let timeoutId: number;
 
-    if (options.actionText) {
-      this._button.className = 'snackbar--button';
-      this._button.textContent = options.actionText;
-      this._button.addEventListener('click', () => {
-        if (this._showing) {
-          if (options.actionHandler && options.actionHandler() === false) return;
-          this._result.action = true;
-        }
-        this.hide();
+    // Add action buttons
+    for (const action of actions) {
+      const button = document.createElement('button');
+      button.className = style.button;
+      button.textContent = action;
+      button.addEventListener('click', () => {
+        clearTimeout(timeoutId);
+        resolve(action);
       });
-      this._element.appendChild(this._button);
+      el.appendChild(button);
     }
 
-    if (callback) {
-      this._onremove.push(callback);
+    // Add timeout
+    if (timeout) {
+      timeoutId = self.setTimeout(
+        () => resolve(''),
+        timeout,
+      );
     }
-  }
+  });
 
-  cancelTimer () {
-    if (this._closeTimer != null) clearTimeout(this._closeTimer);
-  }
-
-  show (parent: Element): Promise<SnackShowResult> {
-    if (this._showing) return Promise.resolve(this._result);
-    this._showing = true;
-    this.cancelTimer();
-    if (parent !== this._element.parentNode) {
-      parent.appendChild(this._element);
-    }
-    this._element.removeAttribute('aria-hidden');
-    this._closeTimer = setTimeout(this.hide.bind(this), this._options.timeout || DEFAULT_TIMEOUT);
-    return new Promise((resolve) => {
-      this._onremove.push(resolve);
-    });
-  }
-
-  hide () {
-    if (!this._showing) return;
-    this._showing = false;
-    this.cancelTimer();
-    this._element.addEventListener('animationend', this.remove.bind(this));
-    this._element.setAttribute('aria-hidden', 'true');
-  }
-
-  remove () {
-    this.cancelTimer();
-    const parent = this._element.parentNode;
-    if (parent) parent.removeChild(this._element);
-    this._onremove.forEach(f => f(this._result));
-    this._onremove = [];
-  }
+  return [el, result];
 }
 
 export default class SnackBarElement extends HTMLElement {
-  private _snackbars: Snack[] = [];
-  private _processingStack = false;
+  private _snackbars: [string, SnackOptions, (action: Promise<string>) => void][] = [];
+  private _processingQueue = false;
 
-  showSnackbar (options: SnackOptions): Promise<SnackShowResult> {
-    return new Promise((resolve) => {
-      const snack = new Snack(options, resolve);
-      this._snackbars.push(snack);
-      this._processStack();
+  /**
+   * Show a snackbar. Returns a promise for the name of the action clicked, or an empty string if no
+   * action is clicked.
+   */
+  showSnackbar(message: string, options: SnackOptions = {}): Promise<string> {
+    return new Promise<string>((resolve) => {
+      this._snackbars.push([message, options, resolve]);
+      if (!this._processingQueue) this._processQueue();
     });
   }
 
-  private async _processStack () {
-    if (this._processingStack === true || this._snackbars.length === 0) return;
-    this._processingStack = true;
-    await this._snackbars[0].show(this);
-    this._snackbars.shift();
-    this._processingStack = false;
-    this._processStack();
+  private async _processQueue() {
+    this._processingQueue = true;
+
+    while (this._snackbars[0]) {
+      const [message, options, resolver] = this._snackbars[0];
+      const [el, result] = createSnack(message, options);
+      // Pass the result back to the original showSnackbar call.
+      resolver(result);
+      this.appendChild(el);
+
+      // Wait for the user to click an action, or for the snack to timeout.
+      await result;
+
+      // Transition the snack away.
+      el.setAttribute('aria-hidden', 'true');
+      await new Promise((resolve) => {
+        el.addEventListener('animationend', () => resolve());
+      });
+      el.remove();
+
+      this._snackbars.shift();
+    }
+
+    this._processingQueue = false;
   }
 }
 

src/lib/SnackBar/styles.css

@@ -22,7 +22,6 @@ snack-bar {
   transform-origin: center;
   color: #eee;
   z-index: 100;
-  pointer-events: none;
   cursor: default;
   will-change: transform;
   animation: snackbar-show 300ms ease forwards 1;
@@ -53,13 +52,13 @@ snack-bar {
   }
 }
 
-.snackbar--text {
+.text {
   flex: 1 1 auto;
   padding: 16px;
   font-size: 100%;
 }
 
-.snackbar--button {
+.button {
   position: relative;
   flex: 0 1 auto;
   padding: 8px;
@@ -75,16 +74,15 @@ snack-bar {
   font-size: 100%;
   text-transform: uppercase;
   text-align: center;
-  pointer-events: all;
   cursor: pointer;
   overflow: hidden;
   transition: background-color 200ms ease;
   outline: none;
 }
-.snackbar--button:hover {
+.button:hover {
   background-color: rgba(0,0,0,0.15);
 }
-.snackbar--button:focus:before {
+.button:focus:before {
   content: '';
   position: absolute;
   left: 50%;

webpack.config.js

@@ -25,6 +25,7 @@ module.exports = function (_, env) {
     path.join(__dirname, 'src/components'),
     path.join(__dirname, 'src/codecs'),
     path.join(__dirname, 'src/custom-els'),
+    path.join(__dirname, 'src/lib'),
   ];
 
   return {
@@ -107,7 +108,7 @@ module.exports = function (_, env) {
               loader: 'typings-for-css-modules-loader',
               options: {
                 modules: true,
-                localIdentName: '[local]__[hash:base64:5]',
+                localIdentName: isProd ? '[hash:base64:5]' : '[local]__[hash:base64:5]',
                 namedExport: true,
                 camelCase: true,
                 importLoaders: 1,
@@ -199,8 +200,11 @@ module.exports = function (_, env) {
 
       new OptimizeCssAssetsPlugin({
         cssProcessorOptions: {
-          zindex: false,
-          discardComments: { removeAll: true }
+          postcssReduceIdents: {
+            counterStyle: false,
+            gridTemplate: false,
+            keyframes: false
+          }
         }
       }),