B-frames are the encoder feature that lets the encoder reference both past and future frames when compressing the current frame. B-frames produce better compression efficiency, which means better visual quality at the same bitrate.

The recommended setting for NVENC: 2 B-frames. The recommended setting for x264: 2 B-frames. The setting is consistent across encoders because the trade-off (slightly higher latency in exchange for noticeably better image quality) is the same regardless of which encoder is producing the stream.

The implementation: in encoder settings, find the B-frames field, set to 2. Save.

The setting is sometimes labeled "max b-frames" or "b-frame count" depending on encoder. The numeric value should be 2 in either case.

The visible effect of 2 B-frames: cleaner motion in the stream, better detail preservation in complex scenes, slightly better compression efficiency overall. The latency cost is negligible for live streaming. Modern decoders handle B-frames without issue. Set the value once. The setting persists across streams.