A rate attached to a rendition
BANDWIDTH describes the peak segment bitrate for the relevant playable variant combination. AVERAGE-BANDWIDTH, when supplied, describes an average. Audio and video renditions associated with a variant must be considered as the specification requires; looking only at video dimensions misses part of the delivery demand.
A 1920 by 1080 rendition can have a lower or higher bitrate than another rendition with identical dimensions. Source complexity, frame rate, codec and encoding choices all matter. A resolution label therefore cannot replace the rate information when comparing the publisher's choices.
Calculating a segment transfer rate
A hypothetical six-second segment containing 3,000,000 bytes represents 24,000,000 bits divided by six seconds, or 4,000,000 bits per second. If it transfers in two seconds, the observed transfer rate for that request is 12,000,000 bits per second. These are different rates derived from the same object.
The media consumes those bytes over six playback seconds, while the connection delivered them during two transfer seconds. That headroom can replenish a buffer. Request setup time, audio and other traffic can affect the complete session, so this isolated example is not a minimum broadband-plan recommendation.
Selection remains a player decision
An adaptive player may use recent transfer measurements, available buffer, decoding ability and its own selection logic. A manifest field does not command every player to choose the same rendition at the same moment. Initial picture quality and switching behaviour can consequently differ.
When rates appear inconsistent, keep both the advertised values and measured object sizes with durations. A publisher can then examine packaging or declarations. Editing BANDWIDTH locally does not re-encode the media, and forcing a higher variant cannot create network or decoder capacity that the device lacks.
Questions about this guide
Is AVERAGE-BANDWIDTH my measured speed?
No. It describes media rate for the variant. Transfer speed must be measured separately.
Does a larger BANDWIDTH number prove better quality?
No. Different codecs, sources and encoding decisions make a simple numeric quality ranking unreliable.