Live streaming has become a popular way to share video content online, and two of the biggest platforms for live streaming are YouTube and Twitch. While both platforms offer live streaming capabilities, there is a significant difference between the two in terms of moving the timestamp in a live stream. In this article, we will explore the technical reasons why YouTube supports moving timestamps and Twitch does not.

At the heart of live streaming is the delivery of video data over the internet to a viewer's device. The protocol used for this delivery has a significant impact on the functionality and capabilities of the video streaming platform. YouTube uses a combination of HTTP and adaptive bitrate streaming (ABR) protocols, while Twitch uses the Real-Time Messaging Protocol (RTMP).

YouTube uses HTTP as the foundation for delivering video content, with chunked transfer encoding used to efficiently transfer large amounts of data. With chunked transfer encoding, the video data is broken down into small chunks and each chunk is delivered to the viewer individually. ABR protocols like Dynamic Adaptive Streaming over HTTP (DASH) or HTTP Live Streaming (HLS) are used by YouTube to dynamically adjust the video quality based on the viewer's network conditions. This allows the player to access any chunk at any time, making it possible to move the timestamp in a live stream.

On the other hand, Twitch uses RTMP for live streaming. RTMP is optimized for low-latency streaming and delivering video in real-time. It does not use HTTP or chunked transfer encoding and does not support ABR. This means that the video data must be delivered in real-time and there is no way to go back and access a specific moment in the video data, resulting in the inability to move the timestamp in a Twitch live stream.

While Twitch's use of RTMP does not allow for moving timestamps, it does offer other benefits like low latency and high-quality real-time video delivery. This makes it an attractive choice for real-time applications like gaming where low latency is critical.

In conclusion, the choice of protocol used for live streaming has a significant impact on the functionality and capabilities of the video streaming platform. YouTube's use of HTTP, chunked transfer encoding, and ABR protocols allows for moving timestamps in live streams, while Twitch's use of RTMP does not. Network engineers should consider these technical differences when choosing a live streaming solution to ensure they select the right protocol to meet their specific requirements and desired trade-offs.

Whether you're a fan of YouTube's support for moving timestamps or Twitch's low latency and high-quality real-time video delivery, both platforms have their unique strengths. Ultimately, the right platform for you will depend on your specific live streaming needs and requirements.