Bitrate Control and QoE-CBR is Better

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By | 2017-02-23T00:56:51+00:00 August 7th, 2016|Articles|Comments Off on Bitrate Control and QoE-CBR is Better

Summary (The MPD)

When distributing video under constrained conditions, the bitrate control technique used to encode the files can have a profound impact on the quality of experience (QoE). Specifically, under some conditions, CBR-encoded files deliver a superior QoE to files encoded using 200% constrained VBR, while also reducing the overall bandwidth delivered. 

For producers concerned with the potential for transient quality issues with CBR-encoded files, 110% constrained VBR avoids these transient quality issues and the QoE-related problems experienced with 200% constrained VBR. Producers currently distributing files encoded using 200% constrained VBR should consider running trials with CBR-encoded files to determine if this improves QoE. 

In addition, the initial file played during HLS playback can have a profound impact on initial QoE. Optimal playback is achieved when the highest rate the playback device can sustain is played first. If it’s not possible to determine this, choose the highest quality “safe” rate, but avoid a situation where the majority of your audience will have to quickly switch down after attempting to play the highest quality stream.

This video shows an introductory video describing the test file and test procedure for tests run at 3200 kbps. Click over to YouTube to view the video in full screen.