建立Myntra的视频平台。第二部分

This is the second article in the series ‘Building Myntra’s Video Platform’. In case you haven’t read the first part, you may refer to the article here.

这是 "建立Myntra的视频平台 "系列的第二篇文章。如果你还没有读过第一部分，你可以参考这篇文章。

In the previous article, we touched upon the types of streaming and the various technologies which exist, the ones which are the best suited in today’s time. In this article, we will delve deeper into aspects like Encoders & Decoders, the kind of client players you can have, glass to glass latency, stream security and the protocols you can use for ingestion, among others.

在上一篇文章中，我们谈到了流媒体的类型和存在的各种技术，这些技术在当今时代是最适合的。在这篇文章中，我们将深入探讨编码器和解码器，你可以拥有什么样的客户端播放器，玻璃与玻璃之间的延迟，流的安全性和你可以用来摄取的协议等方面。

Video On Demand (VOD) vs Live Streaming

视频点播（VOD）与实时流媒体

It is important to understand the distinction between Video On Demand (VOD) & Live Streaming. In layman terms, VOD is like pre-recorded content and it allows users to access the video content whenever and wherever they want to watch them. Live Streaming allows users to view the content creator to be viewed in real time.

了解视频点播（VOD）和实时流媒体之间的区别很重要。通俗地说，VOD就像预先录制的内容，它允许用户随时随地访问视频内容，观看它们。实时流媒体允许用户实时查看创作者的内容。

Both VOD and Live Stream experience can be powered through HLS. The manifest files differ slightly in both. The Master Playlist continues to remain the same however the Media Playlists differ slightly.

VOD和实时流体验都可以通过HLS来实现。两者的清单文件略有不同。主播放列表继续保持不变，但媒体播放列表略有不同。

The Media Playlist for VOD has a #EXT-X-ENDLIST tag. Also for a Live Stream, the Media Playlist files keep on changing continuously. The Media Playlist describes the current active video segments. It has something known as Playlist length. Playlist Length is defined as the maximum number of segments or entries a Media Playlist can contain. As the live stream continues new segments get added until the Playlist size is breached at that point the older ones keep on getting removed. For VOD Playlist length is not applicable and it contains the entries of all segments.

VOD的媒体播放列表有一个#EXT-X-ENDLIST标签。对于直播流来说，媒体播放列表文件也在不断变化。媒体播放列表描述了当...