What is Quality-Defined Variable Bitrate (QVBR)?

To address the shortcomings of traditional Constant Bitrate (CBR) and Variable Bitrate (VBR) rate control modes, AWS Elemental created Quality-Defined Variable Bitrate, or QVBR, a content-conscious version of VBR bitrate control.

QVBR analyzes every macroblock, frame, and scene in the video source, and automatically allocates bits to address information differences: higher bitrate use during complex video segments, and lower bitrate use during less complex video segments.

The result: an enhanced version of variable bitrate control that minimizes wasted bits and scales video bitrate to maintain consistent video quality.

How QVBR bitrate savings and benefits stack up for video providers:

• Reduces video output bitrates up to 50 percent
• Saves video content storage and delivery costs: No wasted bits
• No additional cost to use with AWS Elemental encoding software and media services
• Easy operation: Choose one setting for any type of source content
• Quick start: Player changes not required
• Built into encoder: No latency or extra analysis pass
• Multi-codec: Use AVC or choose HEVC for further compression savings
• Works for live video (events or 24/7 channels) and VOD applications: Broadcast, OTT, streaming, download, and more
• Mix and match CBR, VBR, QVBR renditions in the same ABR set
• You see dramatic improvements in video encoding efficiency and video encoding quality
• Your customers receive a superior and consistent viewing experience

More infor, How Does Quality-Defined Variable Bitrate Improve Video Quality?

Source: https://aws.amazon.com/media/tech/quality-defined-variable-bitrate-qvbr/