@remotion/media-parser/dist/containers/mp3/id3.js

A pure JavaScript library for parsing video files

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.parseId3 = void 0;
function combine28Bits(a, b, c, d) {
    // Mask each number to ignore first bit (& 0x7F)
    const val1 = a & 0x7f; // 7 bits from first byte
    const val2 = b & 0x7f; // 7 bits from second byte
    const val3 = c & 0x7f; // 7 bits from third byte
    const val4 = d & 0x7f; // 7 bits from fourth byte
    // Combine all values using bitwise operations
    return (val1 << 21) | (val2 << 14) | (val3 << 7) | val4;
}
const parseId3 = ({ state }) => {
    const { iterator } = state;
    if (iterator.bytesRemaining() < 9) {
        return;
    }
    const { returnToCheckpoint } = iterator.startCheckpoint();
    iterator.discard(3);
    const versionMajor = iterator.getUint8();
    const versionMinor = iterator.getUint8();
    const flags = iterator.getUint8();
    const sizeArr = iterator.getSlice(4);
    const size = combine28Bits(sizeArr[0], sizeArr[1], sizeArr[2], sizeArr[3]);
    if (iterator.bytesRemaining() < size) {
        returnToCheckpoint();
        return;
    }
    const entries = [];
    const initial = iterator.counter.getOffset();
    while (iterator.counter.getOffset() < size + initial) {
        const name = versionMajor === 3 || versionMajor === 4
            ? iterator.getByteString(4, true)
            : iterator.getByteString(3, true);
        if (name === '') {
            iterator.discard(size + initial - iterator.counter.getOffset());
            break;
        }
        const s = versionMajor === 4
            ? iterator.getSyncSafeInt32()
            : versionMajor === 3
                ? iterator.getUint32()
                : iterator.getUint24();
        if (versionMajor === 3 || versionMajor === 4) {
            iterator.getUint16(); // flags
        }
        let subtract = 0;
        if (!name.startsWith('W')) {
            iterator.getUint8(); // encoding
            subtract += 1;
        }
        if (name === 'APIC') {
            const { discardRest } = iterator.planBytes(s - subtract);
            const mimeType = iterator.readUntilNullTerminator();
            iterator.getUint16(); // picture type
            const description = iterator.readUntilNullTerminator();
            iterator.discard(1);
            const data = discardRest();
            state.images.addImage({
                data,
                description,
                mimeType,
            });
        }
        else {
            const information = iterator.getByteString(s - subtract, true);
            entries.push({
                key: name,
                value: information,
                trackId: null,
            });
        }
    }
    state.structure.getMp3Structure().boxes.push({
        type: 'id3-header',
        flags,
        size,
        versionMajor,
        versionMinor,
        metatags: entries,
    });
};
exports.parseId3 = parseId3;