ATSC 3.0 and AV1 Video Codec Integration

This article examines the relationship between the ATSC 3.0 broadcast standard and the royalty-free AV1 video codec. It outlines ATSC 3.0's current reliance on HEVC, explores the technical pathways for integrating AV1 into both broadcast and broadband streams, and evaluates the hardware and standardization challenges that affect future adoption.

The Current ATSC 3.0 Baseline: HEVC

ATSC 3.0 (branded commercially as NextGen TV) currently specifies High Efficiency Video Coding (HEVC/H.265) as its primary video compression format under the ATSC A/341 standard. When the Advanced Television Systems Committee finalized the core physical and video layers of ATSC 3.0, HEVC was the most mature, commercially viable codec offering sufficient compression efficiency for 4K Ultra HD, High Dynamic Range (HDR), and Wide Color Gamut (WCG) broadcasts. Consequently, every certified ATSC 3.0 receiver and television sold today includes dedicated hardware decoding for HEVC.

Architectural Flexibility for Codec Integration

Unlike legacy ATSC 1.0, which was rigidly tied to MPEG-2 transport streams, ATSC 3.0 is built on an Internet Protocol (IP) backbone. It utilizes Real-Time Object Delivery over Unidirectional Transport (ROUTE) and MPEG Media Transport (MMT), alongside Dynamic Adaptive Streaming over HTTP (DASH) for media delivery.

Because ATSC 3.0 treats media streams as IP data packets, its architecture is inherently codec-agnostic. The system is split into two primary delivery paths where AV1 can be considered:

1. Broadband (Hybrid Delivery): ATSC 3.0 supports hybrid services where core content is sent over-the-air (OTA) and interactive or supplemental video is delivered via broadband. Because modern smart TVs often include native AV1 decoders for streaming platforms like YouTube and Netflix, broadcasters can leverage AV1 over the ATSC 3.0 broadband path today via standard DASH packaging without modifying OTA transmission standards.
2. Over-the-Air (Linear Broadcast): Integrating AV1 into the primary broadcast stream requires formal updates to the ATSC A/341 video standard. The standard would need to define signaling, packaging constraints, and profile requirements specifically for AV1 elementary streams within ROUTE/DASH and MMT containers.

Drivers for AV1 Consideration

Broadcasters and standards bodies consider AV1 integration for two primary reasons:

• Bandwidth Efficiency: AV1, developed by the Alliance for Open Media (AOMedia), provides roughly a 20% to 30% improvement in compression efficiency over HEVC at equivalent quality levels. In a broadcast environment where RF bandwidth is strictly capped at 6 MHz per channel, greater efficiency allows stations to transmit multiple 1080p or 4K HDR streams alongside interactive data services without severe quality degradation.
• Licensing and Royalties: AV1 is an open-source, royalty-free codec. The complex, fragmented patent pool structure associated with HEVC licensing has long been a challenge for software developers, content distributors, and equipment manufacturers. A royalty-free alternative simplifies deployment economics, particularly for software-defined receiver ecosystems.

Challenges and Implementation Roadblocks

Despite the technical feasibility, significant hurdles remain before AV1 can become a standard broadcast format in ATSC 3.0:

• Legacy Hardware Incompatibility: Millions of ATSC 3.0 televisions and external tuner boxes have already been deployed with silicon that only decodes HEVC for broadcast demodulation. If a broadcaster switched its primary OTA stream to AV1, existing NextGen TV sets would render a blank screen unless equipped with a field-upgradable chipset capable of AV1 decoding.
• Silicon and Tuner Constraints: While high-end smart TVs frequently feature AV1 silicon for OTT streaming, entry-level converter boxes and budget tuners often lack the processing power for AV1 decoding. Standardizing AV1 for broadcast would require hardware parity across all price tiers of ATSC 3.0 receivers.
• Standardization Timelines: Modifying the ATSC A/341 specification requires industry consensus among broadcasters, consumer electronics manufacturers, and transmission equipment vendors.

Current Status and Outlook

As of now, AV1 is not an approved video format for linear over-the-air ATSC 3.0 broadcasts. The immediate interaction between the two technologies remains confined to the hybrid broadband layer of ATSC 3.0 interactive applications. Long-term integration for OTA broadcast will depend on the standard's governance process and the universal adoption of AV1 hardware decoding in future consumer television chipsets.