Single NAL Unit Packet Decoding Order Number for RTP Multi-Stream Transmission

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing video transmission protocols, such as RTP, face inefficiencies when using single NAL unit packets in multi-stream transmission modes due to the need for aggregation packets, which incur overhead and decrease bandwidth efficiency.

Innovation Solution

Incorporating decoding order number information into the single NAL unit packet format, allowing for flexible transmission modes and parameters, enabling more efficient use of single NAL unit packets in both unicast and multi-stream transmission scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If aggregation packets are used for single NAL unit transmission in multi-stream mode, then transmission compatibility is improved, but packet overhead increases and bandwidth efficiency decreases

Engineering Contradiction:

Improvetransmission compatibilityVSAvoidbandwidth efficiency

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent extracts the decoding order number information from the aggregation packet structure and places it directly into the single NAL unit packet header. This allows the single NAL unit packet to carry its own ordering information independently, eliminating the need for aggregation packets in multi-stream transmission and thereby reducing packet overhead while maintaining transmission compatibility.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The single NAL unit packet format is enhanced to serve multiple functions: it carries video data, includes decoding order number information in its header, and can be transmitted independently without aggregation packets. This multi-functionality allows the same packet format to work efficiently in both unicast and multi-stream transmission modes, improving bandwidth efficiency while maintaining adaptability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Device complexity

If single NAL unit packets are used without decoding order number, then packet structure simplicity is improved, but transmission order ambiguity increases in multi-stream mode

Engineering Contradiction:

Improvepacket structure complexityVSAvoiddecoding order information

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The decoding order number is embedded in the packet header during the packetization process, before transmission. This preliminary inclusion of ordering information ensures that receivers can correctly reorder packets without requiring complex post-reception processing, maintaining packet structure simplicity while preventing order ambiguity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The packet structure is segmented into distinct fields: the decoding order number occupies specific bits in the header (bits 2-9 of the 10-bit header), separating ordering information from video data. This segmentation allows the packet to carry both types of information clearly without increasing overall complexity, as each component has its designated location.

Inventive Principle:

Principle #1Segmentation

3Measurement precision

If decoding order number is added to single NAL unit packet header, then transmission precision is improved, but header size increases

Engineering Contradiction:

Improvedecoding order precisionVSAvoidpacket header length

Core Design Contradiction:

Measurement precisionVSLength of stationary object

Solution Approach 1:

The patent modifies the NAL unit packet header parameters by allocating specific bits (bits 2-9) for the decoding order number, changing the header from carrying only video data indicators to also including ordering information. This parameter change enables precise tracking of decoding order while keeping the header size fixed and manageable through efficient bit allocation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The packet header structure is designed with flexible field assignments where the decoding order number occupies a compact 8-bit space within the overall header framework. This flexible structure allows the header to accommodate additional information without significant size increase, effectively adding functionality with minimal overhead through efficient use of header space.

Inventive Principle:

Principle #30Flexible shells and thin films

Data Source

PatentEP3005700B1Single network abstraction layer unit packets with decoding order number for video coding

Publication Date: 2019.04.10 QUALCOMM INC

Figure 1
Figure 2
Figure 3

AI summary

A method for processing video data in a real-time transport protocol (RTP) payload includes encapsulating video data in a single network abstraction layer (NAL) unit packet for an RTP session. The single NAL unit packet contains a single NAL unit. The method may also include encapsulating decoding order number information in the single NAL unit packet based on at least one of: the RTP session being in a multi-stream transmission (MST) mode, or a maximum number of NAL units that may precede the NAL unit in a de-packetization buffer in reception order and follow the NAL unit in decoding order being greater than 0.