PRODUCTS
People today expect videos to start instantly, and even a small delay can be frustrating. A delay of even a second can feel like an eternity for viewers, and for many, that brief pause is enough to hit the back button. Studies show that a delay as short as two seconds can cause viewers to drop off, and by five seconds, the number spikes dramatically. But what’s causing this delay, and how can we reduce it? Let’s take a closer look at video startup time and the factors that impact it.
Video startup time (VST) is the delay between when a user presses the play button and when the video begins to play. This delay includes various processes such as establishing a connection, fetching the video content, and starting playback. For developers, VST is an important metric because it directly impacts their platform performance and user interaction, if the delay is too long, users may abandon the video, leading to a drop in engagement and potential revenue loss for OTT platforms or streaming services.
When it comes to start up time, there are two metrics video startup time (VST) and aggregate startup time (AST), it’s important to differentiate between them.
VST measures the duration from when a user clicks play to when the first frame of video appears. It reflects the responsiveness of the video playback system and is influenced by factors like network conditions, encoding efficiency, and the video player's performance.
In contrast, aggregate startup time (AST) includes the entire viewer experience, including:
Understanding both metrics helps developers pinpoint delays in the video delivery process. A high AST relative to VST may indicate issues with page or player load times, while a high VST suggests the need for optimization in video streaming itself.
In this blog, we will explore video startup time, highlighting its significance and the key differences that impact user experience.
Viewer perception of video startup time (VST) and post-start buffering is influenced by user tolerance for delays, which varies across different types of content. Statistics reveal that users are increasingly intolerant of slow video startup times, with various studies indicating alarming abandonment rates.
Video startup time is measured as the total time from the user’s action (pressing play) to the first frame of video being rendered on their screen. This includes multiple stages:
Each of these stages adds to the overall startup time, and optimizing these processes is vital to ensure a fast, smooth playback experience for users.
There are several technical factors contribute to video startup time (VST), each impacting the speed at which a video begins to play. Understanding and optimizing these factors is crucial for developers who want to ensure fast, seamless streaming experiences.
Network conditions
Network bandwidth and latency are primary contributors to VST. When users have high bandwidth and low latency connections, video data can be fetched quickly, reducing the startup time. However, in low-bandwidth environments or when network latency is high, the video player may need to buffer more data before playback, leading to longer startup delays.
For developers, optimizing video streams for variable network conditions is key. This can be achieved through techniques like adaptive bitrate streaming (ABR), which adjusts the video quality based on the user’s available bandwidth.
Encoding and bitrate selection
The way video content is encoded plays a role in determining VST. Efficient encoding techniques reduce the file size without sacrificing quality, leading to faster load times. However, choosing the wrong bitrate or encoding settings can lead to longer startup times. If a video is encoded with a high bitrate, it will require more data to be loaded initially, which can delay playback, especially on lower-speed connections.
Content delivery network (CDN) performance
A CDN's ability to cache content at edge servers close to users can dramatically improve video startup times. When video content is served from a server geographically closer to the viewer, it reduces the round-trip time required to fetch data, enabling faster video startup.
CDN performance also relies on cache hit ratios, where frequently accessed content is stored in local caches. A higher cache hit ratio means video content is retrieved from the nearest edge server, decreasing VST.
Player optimization
The design and efficiency of the video player itself also affect VST. Different players handle buffering and streaming differently. For example, some players buffer a significant portion of the video before starting playback, while others begin playback almost immediately by using adaptive streaming to improve startup times. Additionally, how a player manages ABR and handles buffering events, such as switching bitrates mid-stream, can also influence VST.
Optimizing video startup time (VST) is useful for providing users with a better viewing experience. Developers can implement the following techniques to improve VST and ensure faster video delivery:
Adaptive bitrate streaming (ABR)
Adaptive Bitrate Streaming (ABR) is a widely used technique that adjusts video quality based on the user’s available bandwidth in real-time. When ABR is implemented, the video player begins playback with a lower bitrate and progressively increases the quality as the connection stabilizes, ensuring that users experience minimal buffering and a faster startup time. By matching video quality to network conditions, developers can reduce the initial load time, allowing the video to start sooner without waiting for the full high-quality stream to buffer.
Pre-fetching and caching
Pre-fetching and caching are necessary techniques for reducing video startup time, especially for frequently accessed content. Caching involves storing content closer to the user, usually on edge servers within a content delivery network (CDN). This shortens the distance that data needs to travel, reducing latency and enabling faster delivery. Pre-fetching, on the other hand, involves loading content in advance based on predicted user behavior. For instance, when a user is browsing through a list of videos, the player can begin fetching the video data of likely selections in the background, reducing the startup time when they press play.
Optimized encoding
Efficient video encoding plays a pivotal role in minimizing VST. Properly optimized video files are smaller and load faster, while still maintaining high visual quality. When encoding is not optimized, larger video files take longer to buffer before playback can begin, increasing startup times. Developers should adopt encoding practices that balance compression and quality, ensuring that video files are lightweight enough for fast delivery but still deliver a good viewing experience. Techniques such as multi-bitrate encoding, where different quality versions of the same video are generated, can help ensure that the video starts quickly even in lower-bandwidth scenarios.
Low latency protocols
Using low-latency streaming protocols such as HLS (HTTP live streaming) and DASH (Dynamic adaptive streaming over HTTP) is important for reducing VST, especially in live streaming environments. These protocols allow for video content to be delivered in smaller chunks, enabling the player to start playback without having to download the entire video file. This chunk-based delivery ensures that the first segments of the video are available for immediate playback, allowing users to start watching with minimal delay. These protocols also work well in combination with adaptive streaming, further enhancing startup speed by selecting the appropriate bitrate for the user’s connection.
CDMC
A Cloud digital media controller (CDMC) optimizes media workflows in real-time by managing the flow of data between various media components. It reduces latency by coordinating encoding, storage, and delivery processes, ensuring that video assets are handled efficiently. The CDMC dynamically routes video streams through the most optimal CDNs, minimizing delays and improving overall performance. By automating the orchestration of these tasks, the CDMC enhances Video startup time (VST), allowing content to load faster and providing a smoother viewing experience for users.
Context-aware encoding for tailored content
One of the most effective ways to reduce video startup time is by optimizing the encoding process. With context-aware encoding, developers can tailor the video encoding process to match the specific needs of different devices, network speeds, and geographies. This ensures that users receive a version of the video that is appropriately sized and formatted for their device, reducing the amount of data that needs to be buffered before playback can begin.
For example, a user on a mobile network with limited bandwidth will receive a lower bitrate stream that requires less buffering, while a user on a high-speed connection will get a higher-quality version. This dynamic encoding process helps minimize VST while maintaining optimal video quality for every user.
Adaptive bitrate streaming for seamless playback
Adaptive Bitrate Streaming (ABR) is crucial for ensuring smooth video playback, especially when network conditions are variable. With ABR, the video player can switch between different bitrates in real-time based on the user’s available bandwidth. This not only reduces buffering but also improves video startup time by allowing the video to start at a lower quality and scale up as conditions improve.
Developers can implement adaptive bitrate streaming to ensure that users always experience fast video startup, even on less-than-optimal networks. This strategy helps maintain playback continuity, preventing long delays or buffering interruptions that may drive users away.
Implementing CDN Capabilities for Reduced Latency
Content Delivery Networks (CDNs) play a crucial role in reducing video startup time by caching content at edge servers close to users. When a video is requested, the data is served from the nearest CDN node, reducing the distance it needs to travel and minimizing latency.
By using multi-CDN capabilities, developers can ensure that video content is delivered with minimal delays. This is especially important for global audiences, where users in different regions may experience variable network speeds. With multi-CDN setups, developers can optimize content delivery based on geography, routing traffic through the fastest and most reliable paths to reduce video startup times.
Till now we have understand how Video startup time (VST) can directly impact is a user engagement and retention. With FastPix’s analytics and monitoring tools, developers can gain deep insights into how their videos perform and take actionable steps to optimize startup times across various environments.
Track startup times with view sessions and video QoE analytics insights
FastPix’s view sessions and video QoE (quality of experience) analytics insights give platform the ability to monitor and measure video startup times across different regions, devices, and network conditions. By offering metrics like connection times, buffering events, and time to first frame (TTFF), these features provide an in-depth view of how video content is being consumed.
Developers can use these insights to identify trends in VST, such as regions with high latency or devices that consistently experience delays. This information is necessary for fine-tuning streaming infrastructure and improving the overall performance of video delivery.
Identifying bottlenecks and improving VST
FastPix’s analytics not only tracks VST but also offers actionable insights that help developers identify the root causes of slow startup times. Whether the issue lies in network latency, CDN performance, or inefficient encoding, FastPix’s data-driven insights pinpoint the bottlenecks in the video delivery chain.
For example, if startup time is higher in certain geographies, developers can adjust CDN configurations or encoding profiles to better match local conditions. Similarly, if certain devices are taking longer to start videos, they may need optimized bitrates or tailored encoding settings.
Exception alerts for proactive monitoring
To ensure that video startup time remains within acceptable thresholds, FastPix offers exception alerts. These real-time alerts notify developers whenever VST exceeds a pre-defined threshold, enabling them to take immediate action before it affects a large number of users. This proactive approach allows for quick troubleshooting, minimizing the risk of churn caused by excessive delays.
Developers can set up custom alerts based on specific geographies, devices, or even individual streams, ensuring a highly targeted approach to performance monitoring. By receiving early warnings, they can swiftly address issues, such as switching CDNs, optimizing encoding, or scaling infrastructure, to improve startup time and maintain a high-quality user experience.
Delays, even as short as a few seconds, can lead to abandonment, especially with live content or high-demand streams like sports and gaming. By optimizing key areas such as network conditions, encoding settings, and CDN performance, developers can significantly reduce startup times, improving the overall viewing experience. Techniques like adaptive bitrate streaming, efficient video encoding, and pre-fetching are essential to ensure videos start quickly across different devices and network environments. Focusing on these optimizations not only enhances playback quality but also strengthens long-term user retention and satisfaction.
.png)
.png)
