The introduction of AV1 Film Grain Synthesis has allowed Netflix to retain the authenticity and nostalgia of a movie, while reducing the amount of bandwidth required to stream it.
Typically, film grain is difficult to compress, as traditional compression algorithms struggle to manage the random nature of grain. The result is a trade-off between preserving the grain and reducing the file size.
Today, camera sensor noise brings in its own characteristics, while filmmakers may choose to add their own grain for artistic effect.
Netflix has now introduced AV1 Film Grain Synthesis (FGS) streams. While FGS has been part of the AV1 standard since its inception, it was only enabled it for a limited number of titles during the initial launch of the AV1 codec in 2021.
In a Netflix TechBlog, it was revealed that the Bitrate at the start of the playback has been reduced by 24% and average bitrate by 31.6%. There was also a reduction of approximately 3% in Playback Errors and reduced rebuffering overall.
Start Play was also improved with delay reduced by 10%, potentially due to the lower bitrate, which may help devices reach the target buffer level more quickly.
About 0.7% of viewing hours shifted from lower resolutions (≤ 1080p) to 2160p on 4K-capable devices. Netflix attributes the shift to reduced bitrates at switching points, which make it easier to achieve the highest resolution during a session.
The Hot Spot, Kung Fu Cult Master, Initial D, God of Gamblers II, Baahubali 2: The Conclusion, or Dept. Q (you may need to toggle off HDR from the settings menu) are recommended as titles to experience the new FGS streams.
