105 lines
2.9 KiB
TypeScript
105 lines
2.9 KiB
TypeScript
import type { FrameRate } from "opencut-wasm";
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import type { MediaAsset } from "@/media/types";
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type MediaAssetFpsInput = Pick<MediaAsset, "type" | "fps">;
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const STANDARD_FRAME_RATES: Array<{ value: number; rate: FrameRate }> = [
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{ value: 24_000 / 1_001, rate: { numerator: 24_000, denominator: 1_001 } },
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{ value: 24, rate: { numerator: 24, denominator: 1 } },
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{ value: 25, rate: { numerator: 25, denominator: 1 } },
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{ value: 30_000 / 1_001, rate: { numerator: 30_000, denominator: 1_001 } },
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{ value: 30, rate: { numerator: 30, denominator: 1 } },
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{ value: 48, rate: { numerator: 48, denominator: 1 } },
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{ value: 50, rate: { numerator: 50, denominator: 1 } },
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{ value: 60_000 / 1_001, rate: { numerator: 60_000, denominator: 1_001 } },
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{ value: 60, rate: { numerator: 60, denominator: 1 } },
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{ value: 120, rate: { numerator: 120, denominator: 1 } },
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];
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const STANDARD_FRAME_RATE_TOLERANCE = 0.01;
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export function frameRateToFloat(rate: FrameRate): number {
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return rate.numerator / rate.denominator;
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}
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export function frameRatesEqual({
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a,
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b,
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}: {
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a: FrameRate;
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b: FrameRate;
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}): boolean {
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return a.numerator === b.numerator && a.denominator === b.denominator;
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}
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export function floatToFrameRate(fps: number): FrameRate {
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const standard = STANDARD_FRAME_RATES.find(
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(candidate) => Math.abs(fps - candidate.value) <= STANDARD_FRAME_RATE_TOLERANCE,
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);
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if (standard) return standard.rate;
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if (Number.isInteger(fps)) {
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return { numerator: fps, denominator: 1 };
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}
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const ARBITRARY_DENOMINATOR = 1_000_000;
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const scaledNumerator = Math.round(fps * ARBITRARY_DENOMINATOR);
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const divisor = gcd({
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left: scaledNumerator,
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right: ARBITRARY_DENOMINATOR,
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});
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return {
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numerator: scaledNumerator / divisor,
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denominator: ARBITRARY_DENOMINATOR / divisor,
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};
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}
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function gcd({ left, right }: { left: number; right: number }): number {
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let a = Math.abs(left);
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let b = Math.abs(right);
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while (b !== 0) {
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const remainder = a % b;
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a = b;
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b = remainder;
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}
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return a || 1;
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}
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export function getHighestImportedVideoFps({
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mediaAssets,
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}: {
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mediaAssets: MediaAssetFpsInput[];
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}): number | null {
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let highestFps: number | null = null;
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for (const asset of mediaAssets) {
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const fps = asset.fps ?? Number.NaN;
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if (asset.type !== "video") continue;
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if (!Number.isFinite(fps) || fps <= 0) continue;
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highestFps = highestFps === null ? fps : Math.max(highestFps, fps);
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}
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return highestFps;
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}
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export function getRaisedProjectFpsForImportedMedia({
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currentFps,
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importedAssets,
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}: {
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currentFps: FrameRate;
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importedAssets: MediaAssetFpsInput[];
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}): FrameRate | null {
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const highestImportedVideoFps = getHighestImportedVideoFps({
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mediaAssets: importedAssets,
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});
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const currentFpsFloat = frameRateToFloat(currentFps);
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if (highestImportedVideoFps === null || highestImportedVideoFps <= currentFpsFloat) {
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return null;
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}
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return floatToFrameRate(highestImportedVideoFps);
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}
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