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preloadVideo()

此函数是 @remotion/preload 包的一部分。

此函数在 DOM 中预加载视频，以便在挂载视频标签时可以立即播放。

虽然预加载对于渲染并非必需，但它可以帮助在 <Player /> 和 Studio 中实现无缝播放。

preloadVideo() 的替代方案是 prefetch() API。请参阅 @remotion/preload vs prefetch() 来决定哪个更适合您的用例。

用法​

tsx
import { preloadVideo } from "@remotion/preload";
 
const unpreload = preloadVideo(
  "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4"
);
 
// If you want to un-preload the video later
unpreload();
tsx
import { preloadVideo } from "@remotion/preload";
 
const unpreload = preloadVideo(
  "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4"
);
 
// If you want to un-preload the video later
unpreload();

工作原理​

  • 在 Firefox 上，它会在文档的 head 元素中附加一个 <link rel="preload" as="video"> 标签。
  • 在其他浏览器上，它会在文档的 body 元素中附加一个 <video preload="auto"> 标签。

处理重定向​

如果视频 URL 重定向到另一个 URL，则无法预加载原始 URL。

如果您包含的 URL 是未知的，请使用 resolveRedirect() 来以编程方式获取遵循潜在重定向的最终 URL。

如果资源不支持 CORS，resolveRedirect() 将失败。如果资源重定向，并且不支持 CORS，则无法预加载该资产。

此代码片段尝试尽最大努力预加载视频。如果无法解析重定向，则尝试预加载原始 URL。

tsx
import { preloadVideo, resolveRedirect } from "@remotion/preload";
import { Video } from "remotion";
 
// This code gets executed immediately once the page loads
let urlToLoad =
  "https://player.vimeo.com/external/291648067.hd.mp4?s=94998971682c6a3267e4cbd19d16a7b6c720f345&profile_id=175&oauth2_token_id=57447761";
 
resolveRedirect(urlToLoad)
  .then((resolved) => {
    // Was able to resolve a redirect, setting this as the video to load
    urlToLoad = resolved;
  })
  .catch((err) => {
    // Was unable to resolve redirect e.g. due to no CORS support
    console.log("Could not resolve redirect", err);
  })
  .finally(() => {
    // In either case, we try to preload the original or resolved URL
    preloadVideo(urlToLoad);
  });
 
// This code only executes once the component gets mounted
const MyComp: React.FC = () => {
  // If the component did not mount immediately, this will be the resolved URL.
 
  // If the component mounted immediately, this will be the original URL.
  // In that case preloading is ineffective anyway.
  return <Video src={urlToLoad}></Video>;
};
tsx
import { preloadVideo, resolveRedirect } from "@remotion/preload";
import { Video } from "remotion";
 
// This code gets executed immediately once the page loads
let urlToLoad =
  "https://player.vimeo.com/external/291648067.hd.mp4?s=94998971682c6a3267e4cbd19d16a7b6c720f345&profile_id=175&oauth2_token_id=57447761";
 
resolveRedirect(urlToLoad)
  .then((resolved) => {
    // Was able to resolve a redirect, setting this as the video to load
    urlToLoad = resolved;
  })
  .catch((err) => {
    // Was unable to resolve redirect e.g. due to no CORS support
    console.log("Could not resolve redirect", err);
  })
  .finally(() => {
    // In either case, we try to preload the original or resolved URL
    preloadVideo(urlToLoad);
  });
 
// This code only executes once the component gets mounted
const MyComp: React.FC = () => {
  // If the component did not mount immediately, this will be the resolved URL.
 
  // If the component mounted immediately, this will be the original URL.
  // In that case preloading is ineffective anyway.
  return <Video src={urlToLoad}></Video>;
};

参见​