AT&T Video Optimizer
Video Start-up Delay
As a developer, you need to be able to examine the phases of video startup and identify delays, so that you can balance delivery quality and video quality with your viewer's patience level.
There are two phases in video startup: Authentication and downloading.
Authentication includes digital rights management (DRM) initialization, confirmation, and obtaining the manifest file. Downloading includes downloading the video file segments and Adaptive Bitrate (ABR) segment buffering.
People don't like to wait, but in order for your video to be authenticated, begin downloading, and store some file segments in the buffer, some waiting is required.
There is a constant balancing act in streaming video. In this case, balancing between the viewer's impatience and the time required to guarantee a smooth playback. They may not like waiting for startup, but they won’t like it any better if the video starts quickly, but then keeps stalling.
Best Practice Recommendation
The Best Practice recommendation is to balance the video viewer's desire for a quick startup with the video player's need to have enough video in the buffer to prevent stalls. To this end, it is helpful if you can view startup delays in order to manage them.
The Video Optimizer can help you identify video stream startup delays. Startup delays in themselves are not the problem. The problem is the length of the delay and the viewer not knowing what is happening. Besides achieving authentication, downloading, and establishing sufficient buffer capacity, the more you can do to inform your viewer about what is happening, the better.
It is important to resolve startup delays and move through the startup phases as quickly as possible. People by nature don't like to wait.
You can try experimenting with different delivery strategies to speed things up, test again with the Video Optimizer and compare the results.
If there unavoidable delays, you might consider offering a slight distraction to your viewer while they are waiting. You could provide information about the video, a quick message telling them that their video will be starting soon, or something to make them smile.
Just let them know you haven't forgotten them and that the show will go on.
Video and other types of rich media are on the rise in mobile apps and in the future we plan on offering more guidance on streaming and other video technology in our Mobile Development Best Practices recommendations.