Extract processor classes into separate folders

Author: xenova

src/base/feature_extraction_utils.js

@@ -0,0 +1,54 @@
+import { FEATURE_EXTRACTOR_NAME } from "../utils/constants.js";
+import { Callable } from "../utils/generic.js";
+import { getModelJSON } from "../utils/hub.js";
+
+/**
+ * Base class for feature extractors.
+ */
+export class FeatureExtractor extends Callable {
+    /**
+     * Constructs a new FeatureExtractor instance.
+     *
+     * @param {Object} config The configuration for the feature extractor.
+     */
+    constructor(config) {
+        super();
+        this.config = config
+    }
+
+    /**
+     * Instantiate one of the processor classes of the library from a pretrained model.
+     * 
+     * The processor class to instantiate is selected based on the `image_processor_type` (or `feature_extractor_type`; legacy)
+     * property of the config object (either passed as an argument or loaded from `pretrained_model_name_or_path` if possible)
+     * 
+     * @param {string} pretrained_model_name_or_path The name or path of the pretrained model. Can be either:
+     * - A string, the *model id* of a pretrained processor hosted inside a model repo on huggingface.co.
+     *   Valid model ids can be located at the root-level, like `bert-base-uncased`, or namespaced under a
+     *   user or organization name, like `dbmdz/bert-base-german-cased`.
+     * - A path to a *directory* containing processor files, e.g., `./my_model_directory/`.
+     * @param {import('../utils/hub.js').PretrainedOptions} options Additional options for loading the processor.
+     * 
+     * @returns {Promise<FeatureExtractor>} A new instance of the Processor class.
+     */
+    static async from_pretrained(pretrained_model_name_or_path, options) {
+        const preprocessorConfig = await getModelJSON(pretrained_model_name_or_path, FEATURE_EXTRACTOR_NAME, true, options);
+        return new this(preprocessorConfig);
+    }
+}
+
+
+/**
+ * Helper function to validate audio inputs.
+ * @param {any} audio The audio data.
+ * @param {string} feature_extractor The name of the feature extractor.
+ * @private
+ */
+export function validate_audio_inputs(audio, feature_extractor) {
+    if (!(audio instanceof Float32Array || audio instanceof Float64Array)) {
+        throw new Error(
+            `${feature_extractor} expects input to be a Float32Array or a Float64Array, but got ${audio?.constructor?.name ?? typeof audio} instead. ` +
+            `If using the feature extractor directly, remember to use \`read_audio(url, sampling_rate)\` to obtain the raw audio data of the file/url.`
+        )
+    }
+}