77 lines
3.1 KiB
JavaScript
77 lines
3.1 KiB
JavaScript
|
"use strict";
|
||
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
||
|
|
exports.WavPack = void 0;
|
||
|
|
const Token = require("token-types");
|
||
|
|
const FourCC_1 = require("../common/FourCC");
|
||
|
|
const SampleRates = [6000, 8000, 9600, 11025, 12000, 16000, 22050, 24000, 32000, 44100,
|
||
|
|
48000, 64000, 88200, 96000, 192000, -1];
|
||
|
|
class WavPack {
|
||
|
|
static isBitSet(flags, bitOffset) {
|
||
|
|
return WavPack.getBitAllignedNumber(flags, bitOffset, 1) === 1;
|
||
|
|
}
|
||
|
|
static getBitAllignedNumber(flags, bitOffset, len) {
|
||
|
|
return (flags >>> bitOffset) & (0xffffffff >>> (32 - len));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
/**
|
||
|
|
* WavPack Block Header
|
||
|
|
*
|
||
|
|
* 32-byte little-endian header at the front of every WavPack block
|
||
|
|
*
|
||
|
|
* Ref: http://www.wavpack.com/WavPack5FileFormat.pdf (page 2/6: 2.0 "Block Header")
|
||
|
|
*/
|
||
|
|
WavPack.BlockHeaderToken = {
|
||
|
|
len: 32,
|
||
|
|
get: (buf, off) => {
|
||
|
|
const flags = Token.UINT32_LE.get(buf, off + 24);
|
||
|
|
const res = {
|
||
|
|
// should equal 'wvpk'
|
||
|
|
BlockID: FourCC_1.FourCcToken.get(buf, off),
|
||
|
|
// 0x402 to 0x410 are valid for decode
|
||
|
|
blockSize: Token.UINT32_LE.get(buf, off + 4),
|
||
|
|
// 0x402 (1026) to 0x410 are valid for decode
|
||
|
|
version: Token.UINT16_LE.get(buf, off + 8),
|
||
|
|
// 40-bit total samples for entire file (if block_index == 0 and a value of -1 indicates an unknown length)
|
||
|
|
totalSamples: /* replace with bigint? (Token.UINT8.get(buf, off + 11) << 32) + */ Token.UINT32_LE.get(buf, off + 12),
|
||
|
|
// 40-bit block_index
|
||
|
|
blockIndex: /* replace with bigint? (Token.UINT8.get(buf, off + 10) << 32) + */ Token.UINT32_LE.get(buf, off + 16),
|
||
|
|
// 40-bit total samples for entire file (if block_index == 0 and a value of -1 indicates an unknown length)
|
||
|
|
blockSamples: Token.UINT32_LE.get(buf, off + 20),
|
||
|
|
// various flags for id and decoding
|
||
|
|
flags: {
|
||
|
|
bitsPerSample: (1 + WavPack.getBitAllignedNumber(flags, 0, 2)) * 8,
|
||
|
|
isMono: WavPack.isBitSet(flags, 2),
|
||
|
|
isHybrid: WavPack.isBitSet(flags, 3),
|
||
|
|
isJointStereo: WavPack.isBitSet(flags, 4),
|
||
|
|
crossChannel: WavPack.isBitSet(flags, 5),
|
||
|
|
hybridNoiseShaping: WavPack.isBitSet(flags, 6),
|
||
|
|
floatingPoint: WavPack.isBitSet(flags, 7),
|
||
|
|
samplingRate: SampleRates[WavPack.getBitAllignedNumber(flags, 23, 4)],
|
||
|
|
isDSD: WavPack.isBitSet(flags, 31)
|
||
|
|
},
|
||
|
|
// crc for actual decoded data
|
||
|
|
crc: new Token.Uint8ArrayType(4).get(buf, off + 28)
|
||
|
|
};
|
||
|
|
if (res.flags.isDSD) {
|
||
|
|
res.totalSamples *= 8;
|
||
|
|
}
|
||
|
|
return res;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
/**
|
||
|
|
* 3.0 Metadata Sub-Blocks
|
||
|
|
* Ref: http://www.wavpack.com/WavPack5FileFormat.pdf (page 4/6: 3.0 "Metadata Sub-Block")
|
||
|
|
*/
|
||
|
|
WavPack.MetadataIdToken = {
|
||
|
|
len: 1,
|
||
|
|
get: (buf, off) => {
|
||
|
|
return {
|
||
|
|
functionId: WavPack.getBitAllignedNumber(buf[off], 0, 6),
|
||
|
|
isOptional: WavPack.isBitSet(buf[off], 5),
|
||
|
|
isOddSize: WavPack.isBitSet(buf[off], 6),
|
||
|
|
largeBlock: WavPack.isBitSet(buf[off], 7)
|
||
|
|
};
|
||
|
|
}
|
||
|
|
};
|
||
|
|
exports.WavPack = WavPack;
|