@remotion/media-parser/dist/containers/iso-base-media/esds/decoder-specific-config.js

A pure JavaScript library for parsing video files

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.parseDecoderSpecificConfig = void 0;
const parseDecoderSpecificConfig = (iterator) => {
    const layerTag = iterator.getUint8();
    const layerSize = iterator.getPaddedFourByteNumber();
    const start = iterator.counter.getOffset();
    if (layerTag !== 5) {
        iterator.discard(layerSize);
        return {
            type: 'unknown-decoder-specific-config',
        };
    }
    // https://csclub.uwaterloo.ca/~pbarfuss/ISO14496-3-2009.pdf
    // 1.6.2.1 AudioSpecificConfig
    const bytes = iterator.getSlice(layerSize);
    iterator.counter.decrement(layerSize);
    iterator.startReadingBits();
    const audioObjectType = iterator.getBits(5);
    const samplingFrequencyIndex = iterator.getBits(4);
    if (samplingFrequencyIndex === 0xf) {
        iterator.getBits(24);
    }
    const channelConfiguration = iterator.getBits(4);
    iterator.stopReadingBits();
    const read = iterator.counter.getOffset() - start;
    if (read < layerSize) {
        iterator.discard(layerSize - read);
    }
    return {
        type: 'mp4a-specific-config',
        audioObjectType,
        samplingFrequencyIndex,
        channelConfiguration,
        asBytes: bytes,
    };
};
exports.parseDecoderSpecificConfig = parseDecoderSpecificConfig;