What is VST?<\/h1>\n
VST = time to render the first frame – time when play button was pressed.<\/em><\/strong><\/p>\n It is the time taken by the video to start after pressing play on it.<\/p>\n Advance caching refers to making the relevant requests, pre-downloading initial segments or even pre-fetching the content to make the VST as low as possible when the content is actually played, by reusing all the cached data.<\/p>\n 1. Creating an app-wide cache singleton:<\/p>\n SimpleCache<\/a> – Cache used by exoplayer to store media data on disk.<\/p>\n LeastRecentlyUsedCacheEvictor<\/a> – Cache management policy used by exoplayer which automatically frees up space when limits are reached.<\/p>\n StandaloneDatabaseProvider<\/a> – DB used by exoplayer internally to persist and manage cache metadata in a robust way. App Wide Cache Creation<\/p><\/div>\n <\/p>\n 2. Creating a cache aware data source:<\/p>\n DefaultHttpDataSource<\/a> – Used as the network (upstream) source to fetch the content if not present in cache (as a fallback or to fetch the content beyond the cached amount)<\/p>\n CacheDataSource<\/a> – Data source capable of reading from cache and falling back to network (using the DefaultHttpDataSource) if and when required.<\/p>\n FLAG_IGNORE_CACHE_ON_ERROR<\/a> – This ensures the playback can fallback to network if cache is unable to be accessed.<\/p>\n Preparation of CacheDataSource<\/p><\/div>\n <\/p>\n 3. Configure Media Item with required URLs:<\/p>\n MediaItem<\/a> – This object represents the media to be played by encapsulating all the essential details about the media content like URI, metadata, License URL (if DRM protected), subtitle info etc.<\/p>\n Creation of a mediaItem<\/p><\/div>\n <\/p>\n 4. Build and prepare an instance of Exoplayer:<\/p>\n Exoplayer.Builder<\/a> – Used to create player instances.<\/p>\n DefaultMediaSourceFactory<\/a> – Creates the media source using the cache aware data source.<\/p>\n Exoplayer initialization and playback preparation<\/p><\/div>\n 5. How does the Caching happen automatically:<\/p>\n When the playback is initiated with a configured CacheDataSource:<\/p>\n 6. Pre-fetch DRM License:<\/p>\nWhy it matters?<\/h1>\n
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Before we dive into caching, let’s look at what usually contributes to VST?<\/h1>\n
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A way to reduce the dreaded “VST” – Setting up advance caching with Exoplayer (Media3)<\/h1>\n
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![\"App](\"https:\/\/www.tothenew.com\/blog\/wp-ttn-blog\/uploads\/2025\/08\/App-Wide-Cache-Creation-1024x406.png\")
<\/a>![\"Preparation](\"https:\/\/www.tothenew.com\/blog\/wp-ttn-blog\/uploads\/2025\/08\/Build-Cache-DataSource-Factory-1024x318.png\")
<\/a>![\"Creation](\"https:\/\/www.tothenew.com\/blog\/wp-ttn-blog\/uploads\/2025\/08\/Creating-a-MediaItem-1024x346.png\")
<\/a>![\"Exoplayer](\"https:\/\/www.tothenew.com\/blog\/wp-ttn-blog\/uploads\/2025\/08\/Exoplayer-creation-1024x346.png\")
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![\"Offline](\"https:\/\/www.tothenew.com\/blog\/wp-ttn-blog\/uploads\/2025\/08\/Locally-downloading-DRM-license-keys-1024x554.png\")
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