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 +1,80 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.StreamReader = void 0;
+const Token = require("token-types");
+const util = require("../../common/Util");
+const initDebug = require("debug");
+const debug = initDebug('music-metadata:parser:musepack:sv8');
+const PacketKey = new Token.StringType(2, 'binary');
+/**
+ * Stream Header Packet part 1
+ * Ref: http://trac.musepack.net/musepack/wiki/SV8Specification#StreamHeaderPacket
+ */
+const SH_part1 = {
+    len: 5,
+    get: (buf, off) => {
+        return {
+            crc: Token.UINT32_LE.get(buf, off),
+            streamVersion: Token.UINT8.get(buf, off + 4)
+        };
+    }
+};
+/**
+ * Stream Header Packet part 3
+ * Ref: http://trac.musepack.net/musepack/wiki/SV8Specification#StreamHeaderPacket
+ */
+const SH_part3 = {
+    len: 2,
+    get: (buf, off) => {
+        return {
+            sampleFrequency: [44100, 48000, 37800, 32000][util.getBitAllignedNumber(buf, off, 0, 3)],
+            maxUsedBands: util.getBitAllignedNumber(buf, off, 3, 5),
+            channelCount: util.getBitAllignedNumber(buf, off + 1, 0, 4) + 1,
+            msUsed: util.isBitSet(buf, off + 1, 4),
+            audioBlockFrames: util.getBitAllignedNumber(buf, off + 1, 5, 3)
+        };
+    }
+};
+class StreamReader {
+    constructor(tokenizer) {
+        this.tokenizer = tokenizer;
+    }
+    async readPacketHeader() {
+        const key = await this.tokenizer.readToken(PacketKey);
+        const size = await this.readVariableSizeField();
+        return {
+            key,
+            payloadLength: size.value - 2 - size.len
+        };
+    }
+    async readStreamHeader(size) {
+        const streamHeader = {};
+        debug(`Reading SH at offset=${this.tokenizer.position}`);
+        const part1 = await this.tokenizer.readToken(SH_part1);
+        size -= SH_part1.len;
+        Object.assign(streamHeader, part1);
+        debug(`SH.streamVersion = ${part1.streamVersion}`);
+        const sampleCount = await this.readVariableSizeField();
+        size -= sampleCount.len;
+        streamHeader.sampleCount = sampleCount.value;
+        const bs = await this.readVariableSizeField();
+        size -= bs.len;
+        streamHeader.beginningOfSilence = bs.value;
+        const part3 = await this.tokenizer.readToken(SH_part3);
+        size -= SH_part3.len;
+        Object.assign(streamHeader, part3);
+        // assert.equal(size, 0);
+        await this.tokenizer.ignore(size);
+        return streamHeader;
+    }
+    async readVariableSizeField(len = 1, hb = 0) {
+        let n = await this.tokenizer.readNumber(Token.UINT8);
+        if ((n & 0x80) === 0) {
+            return { len, value: hb + n };
+        }
+        n &= 0x7F;
+        n += hb;
+        return this.readVariableSizeField(len + 1, n << 7);
+    }
+}
+exports.StreamReader = StreamReader;