1 / 10

AV1 video_ high level bitstream overview

AV1 video was developed by the tAlliance for Open Media as on open and rayality-free video compression format and release in 2018. Presentation describes AV1 bitstream format.

Victor140
Download Presentation

AV1 video_ high level bitstream overview

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. AV1 video: high level bitstream overview

  2. AV1 video format overview • AV1 is an open, royalty-free video codec developed by the Alliance for Open Media (AOMedia); • Open and rayality-free, no licensing fees; • AV1 is open-source, with ongoing improvements driven by contributions from the industry’s leading companies; • Targeted for modern video content: optimized for 4K, 8K, HDR (High dynamic range), and HFR (high frame rates); • Used by YouTube, Netflix, and other major streaming services to deliver high-quality content with reduced bandwidth; • We will use Virinext Bitstream Analyzer for analyzing AV1 files.

  3. High level AV1 bitstream overview At the high level AV1 video is the sequence of Open Bitstream Units (OBUs)

  4. AV1 Open Bitstream Units (OBUs) There are different types of OBUs, including: • Sequence Header OBU: Contains global parameters, such as color space, bit depth, and initial settings for the entire sequence; • Frame Header OBU: Includes frame-specific details like resolution, coding tools, reference frames, and frame type; • Tile Group OBU: Holds compressed data for one or more tiles within a frame; • Metadata OBU: Provides auxiliary information, such as frame timing, HDR metadata, or scalability parameters.

  5. AV1 Sequence Header OBU The Sequence Header OBU contains global video parameters and typically appears at the start of the bitstream. Sequence Header OBU defines settings that apply to the entire sequence of frames, including: • Profile: Specifies the encoding profile (e.g., main, high); • Level: Defines the performance level for decoding, such as supported resolution and frame rate; • Bit depth: Indicates the color depth (e.g., 8-bit, 10-bit); • Color format: Specifies the chroma subsampling (e.g., 4:2:0); • Frame size: Defines the dimensions of the video frames.

  6. AV1 Sequence Header OBU

  7. AV1 Frame Header OBU Frame Header OBU describes every frame in AV1 bitstream. Frame Header OBU, which contains the information required to decode specific frame. Frame Header OBU includes a frame type field, which indicates whether the frame is a keyframe, intra-frame, or inter-frame.

  8. AV1 Tile Group OBU AV1 frames can be split into tiles. Tile is an independently encoded sections of a frame. Each tile contains its own compressed data and can be decoded independently from the others. Tiles can be used for parallel processing for improving encoding and decoding.

  9. AV1 video analysis with Virinext Bitstream Analyzer Screenshot of frame preview, syntax viewer and GOP widgets of AV1 video file opened in Virinext Bitstream Analyzer:

  10. References • Virinext Bitsteam Analyzer - GUI tool for displaying and analyzing coded video and audio streams • AV1 video: high level bitstream overview • AV1 homepage • AV1 Bitstream & Decoding Process Specification

More Related