@remotion/media-parser
Version:
A pure JavaScript library for parsing video files
43 lines (42 loc) • 1.16 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.getChannelCount = void 0;
// https://www.rfc-editor.org/rfc/rfc9639.html#name-channels-bits
const getChannelCount = (iterator) => {
const bits = iterator.getBits(4);
if (bits === 0b0000) {
return 1;
}
if (bits === 0b0001) {
return 2;
}
if (bits === 0b0010) {
return 3;
}
if (bits === 0b0011) {
return 4;
}
if (bits === 0b0100) {
return 5;
}
if (bits === 0b0101) {
return 6;
}
if (bits === 0b0110) {
return 7;
}
if (bits === 0b0111) {
return 8;
}
if (bits === 0b1000 || bits === 0b1001 || bits === 0b1010) {
return 2;
}
// 0b1011..0b1111 are reserved per RFC 9639 §9.1.3 (Channels Bits).
// Some encoders/files in the wild may nonetheless use these values.
// Be lenient and treat them as stereo (2 channels) to keep parsing robust.
if (bits >= 0b1011 && bits <= 0b1111) {
return 2;
}
throw new Error(`Invalid channel count: ${bits.toString(2)}`);
};
exports.getChannelCount = getChannelCount;