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AWS Elemental MediaLive¶
AWS Elemental MediaLive is an AWS managed live video encoding service. It ingests a source stream (over RTP / RTMP / HLS / SRT / other protocols), transcodes into a multi-rendition bitrate ladder for DASH / HLS playback, and pushes outputs to downstream CDNs / packagers.
MediaLive is part of the AWS Elemental media-services family (MediaLive for live encoding, MediaPackage for origin packaging, MediaStore for object storage, MediaTailor for server-side ad insertion, MediaConvert for file-based transcoding).
QVBR — Quality-Defined Variable Bitrate¶
MediaLive's canonical implementation of capped VBR is its QVBR (Quality-Defined Variable Bitrate) rate-control setting. QVBR parameterises the encoder by:
- A target quality level (perceptual target).
- A max bitrate cap that the instantaneous rate must not exceed.
The encoder internally targets the quality level and treats the cap as a ceiling — simple scenes drop well below the cap, complex scenes spike up toward the cap but no higher.
This is the feature Netflix Live relies on post-2026-01-26:
"In our live pipeline, we currently use AWS Elemental MediaLive, where this 'capped' VBR is implemented using the QVBR (Quality-Defined Variable Bitrate) setting." (Source: sources/2026-04-02-netflix-smarter-live-streaming-vbr-at-scale)
Role in Netflix's Live pipeline¶
MediaLive sits at the encoder layer of Netflix Live. Upstream of MediaLive is Netflix's live source ingest; downstream, encoded output feeds Netflix's packager + Open Connect CDN appliances for delivery to viewers.
The Live CBR → capped-VBR cutover on 2026-01-26 was a configuration change at the MediaLive layer (CBR mode → QVBR mode), paired with:
- Netflix's VMAF-matched ladder re-tuning — to fix ≈1-VMAF-point low-rung regressions introduced by the mode change.
- Netflix's nominal- bitrate admission control fix — to keep CDN fleet steering safe under variable per-session traffic.
See patterns/cbr-to-vbr-live-rollout for the full end-to-end rollout playbook.
Stub scope¶
This wiki page is a stub — MediaLive has substantial feature depth beyond the QVBR setting Netflix disclosed (multiple-input failover, channel lifecycle, input switching, captions pipelines, SCTE-35 ad markers, colour pipeline, multi-region redundancy). Expand this page when additional posts covering MediaLive internals or customer architectures are ingested.
Seen in¶
- sources/2026-04-02-netflix-smarter-live-streaming-vbr-at-scale — canonical wiki source; Netflix Live uses MediaLive + QVBR across all Live events as of 2026-01-26.
Related¶
- concepts/capped-vbr-qvbr — the rate-control mode QVBR implements
- concepts/variable-bitrate-vbr
- concepts/bitrate-ladder — MediaLive's output
- systems/netflix-open-connect — downstream delivery
- patterns/cbr-to-vbr-live-rollout
- companies/netflix
- companies/aws