Initial working version

2022-12-22 20:22:22 +11:00
parent ce9675a1cc
commit ced7fa5092
902 changed files with 150252 additions and 0 deletions
@@ -0,0 +1,56 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.OpusParser = void 0;
+const Token = require("token-types");
+const Opus = require("./Opus");
+const VorbisParser_1 = require("../vorbis/VorbisParser");
+/**
+ * Opus parser
+ * Internet Engineering Task Force (IETF) - RFC 6716
+ * Used by OggParser
+ */
+class OpusParser extends VorbisParser_1.VorbisParser {
+    constructor(metadata, options, tokenizer) {
+        super(metadata, options);
+        this.tokenizer = tokenizer;
+        this.lastPos = -1;
+    }
+    /**
+     * Parse first Opus Ogg page
+     * @param {IPageHeader} header
+     * @param {Buffer} pageData
+     */
+    parseFirstPage(header, pageData) {
+        this.metadata.setFormat('codec', 'Opus');
+        // Parse Opus ID Header
+        this.idHeader = new Opus.IdHeader(pageData.length).get(pageData, 0);
+        if (this.idHeader.magicSignature !== "OpusHead")
+            throw new Error("Illegal ogg/Opus magic-signature");
+        this.metadata.setFormat('sampleRate', this.idHeader.inputSampleRate);
+        this.metadata.setFormat('numberOfChannels', this.idHeader.channelCount);
+    }
+    parseFullPage(pageData) {
+        const magicSignature = new Token.StringType(8, 'ascii').get(pageData, 0);
+        switch (magicSignature) {
+            case 'OpusTags':
+                this.parseUserCommentList(pageData, 8);
+                this.lastPos = this.tokenizer.position - pageData.length;
+                break;
+            default:
+                break;
+        }
+    }
+    calculateDuration(header) {
+        if (this.metadata.format.sampleRate && header.absoluteGranulePosition >= 0) {
+            // Calculate duration
+            const pos_48bit = header.absoluteGranulePosition - this.idHeader.preSkip;
+            this.metadata.setFormat('numberOfSamples', pos_48bit);
+            this.metadata.setFormat('duration', pos_48bit / 48000);
+            if (this.lastPos !== -1 && this.tokenizer.fileInfo.size && this.metadata.format.duration) {
+                const dataSize = this.tokenizer.fileInfo.size - this.lastPos;
+                this.metadata.setFormat('bitrate', 8 * dataSize / this.metadata.format.duration);
+            }
+        }
+    }
+}
+exports.OpusParser = OpusParser;