What's the purpose of smooth steaming in aws cloudfront

Smooth Streaming is a specific streaming protocol developed by Microsoft for delivering adaptive bitrate video content. In the context of AWS CloudFront, it's important to understand its purpose and use cases:

1. Adaptive Bitrate Streaming: Smooth Streaming is designed to provide a seamless viewing experience by dynamically adjusting the quality of the video stream based on the viewer's network conditions and device capabilities.

2. Legacy Support: Smooth Streaming is considered a proprietary technology that is widely used in legacy platforms. It's not as common in newer implementations as other streaming formats like HLS (HTTP Live Streaming) or DASH (Dynamic Adaptive Streaming over HTTP).

3. Format Specifics: Smooth Streaming uses an index file to list available streams, which is different from some other streaming protocols.

4. CloudFront Integration: When you enable Smooth Streaming in CloudFront behaviors, it allows CloudFront to distribute Smooth Streaming content without requiring a Microsoft IIS web server as the origin.

5. Origin Considerations: It's crucial to note that if you're using a Microsoft IIS server as your origin, you should not enable Smooth Streaming in the CloudFront cache behaviors. CloudFront cannot use a Microsoft IIS server as an origin if Smooth Streaming is enabled as a cache behavior.

6. Content Preparation: To use Smooth Streaming, your video content needs to be properly packaged in the Smooth Streaming format. This typically involves using an encoder to create the necessary segments and manifest files.

7. Use Cases: Smooth Streaming might be used when you have existing content in this format or when you're targeting platforms that specifically require or perform better with Smooth Streaming.

It's important to understand that simply enabling Smooth Streaming in CloudFront won't automatically improve your streaming experience. The improvement depends on whether your content is actually formatted for Smooth Streaming and if your viewers' devices support this protocol. If you're not specifically using Smooth Streaming formatted content, enabling this option may not have any noticeable effect on your movie streaming experience. For modern streaming setups, other formats like HLS or DASH are more commonly used and widely supported across different devices and platforms.
Sources
Streaming techniques for media - Amazon CloudFront for Media
Deliver video on demand with CloudFront - Amazon CloudFront

This option is applicable for specific use case when you need Microsoft Smooth Streaming as streaming protocol. It's valid for VoD type of content only. And you need to enable it when you don't use IIS server as an origin. You can read a bit more about different streaming protocols here: https://aws.amazon.com/blogs/media/back-to-basics-http-video-streaming/