libsdl-org/aom
Mar 2025 – Dec 2025
8 Months active
Languages Used
CC++
Technical Skills
AV1Algorithm OptimizationC++Image ProcessingPerformance OptimizationQuantization
Jingning Han
PROFILE
Jingning Han
Contributed to the libsdl-org/aom repository over eight months, delivering twelve features and eight bug fixes focused on AV1 video encoding. Developed sharpness-driven quantization, adaptive rate control, and long-term reference frame statistics to improve encoding efficiency and visual quality. Enhanced performance through algorithm and low-level optimizations in C and C++, including transform search speedups and high bit-depth variance support. Addressed stability by fixing motion compensation boundaries, refining skip transform logic, and resolving compiler warnings. Maintained code quality with targeted refactoring and clearer interfaces, while introducing experimental toggles for motion search. The work emphasized robust, maintainable, and high-performance codec development.
Overall Statistics
Feature vs Bugs
60%Features
Repository Contributions
31Total
Bugs
8
Commits
31
Features
12
Lines of code
1,092
Activity Months8
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Andreas AbelMember
Aadi KapurMember
Aadish GoelMember
Aahil MehtaMember
Work History
December 2025
2 Commits • 1 Features
Dec 1, 2025In 2025-12, delivered two focused contributions in libsdl-org/aom aimed at boosting encoding quality and runtime stability. Implemented an adaptive quantization parameter (QP) optimization for ARF generation to improve AV1 encoding efficiency and visual quality. Fixed inter-mode evaluation reliability and resolved compiler warnings, enhancing stability, correctness, and build reliability across the AV1 pipeline. These changes support more robust encoding workflows and reduce noise in builds.
2 Commits • 1 Features
Dec 1, 2025In 2025-12, delivered two focused contributions in libsdl-org/aom aimed at boosting encoding quality and runtime stability. Implemented an adaptive quantization parameter (QP) optimization for ARF generation to improve AV1 encoding efficiency and visual quality. Fixed inter-mode evaluation reliability and resolved compiler warnings, enhancing stability, correctness, and build reliability across the AV1 pipeline. These changes support more robust encoding workflows and reduce noise in builds.
December 2025
November 2025
5 Commits • 3 Features
Nov 1, 2025November 2025 (libsdl-org/aom) — Delivered three features that improve encoding quality, maintainability, and experimentation flexibility. Implemented precise AV1 rate targeting, performed internal encoder refactors for readability and performance, and introduced a compiler flag to toggle experimental motion search. No major bugs fixed this month. Overall impact: more predictable bitrate control, cleaner encoding paths, and faster iteration for experimentation, with demonstrated proficiency in C/C++, performance optimization, and build-system flags.
November 2025
5 Commits • 3 Features
Nov 1, 2025November 2025 (libsdl-org/aom) — Delivered three features that improve encoding quality, maintainability, and experimentation flexibility. Implemented precise AV1 rate targeting, performed internal encoder refactors for readability and performance, and introduced a compiler flag to toggle experimental motion search. No major bugs fixed this month. Overall impact: more predictable bitrate control, cleaner encoding paths, and faster iteration for experimentation, with demonstrated proficiency in C/C++, performance optimization, and build-system flags.
October 2025
2 Commits
Oct 1, 2025October 2025 monthly summary for libsdl-org/aom: Delivered a focused bug fix and code cleanup centered on AV1 intra encoding skip_txfm, improving correctness and stability with minimal risk to bitstream validity. No new features were introduced this month; the primary work improved encoder reliability and maintainability, laying groundwork for future enhancements.
2 Commits
Oct 1, 2025October 2025 monthly summary for libsdl-org/aom: Delivered a focused bug fix and code cleanup centered on AV1 intra encoding skip_txfm, improving correctness and stability with minimal risk to bitstream validity. No new features were introduced this month; the primary work improved encoder reliability and maintainability, laying groundwork for future enhancements.
October 2025
September 2025
1 Commits • 1 Features
Sep 1, 2025September 2025: Focused AV1 encoder enhancement for Shorts in libsdl-org/aom. Introduced a new lt_coded_error statistic in first-pass encoding statistics to evaluate prediction error when using a long-term reference frame, updated accumulation/normalization to incorporate the metric, and integrated last2_frame as a potential long-term reference. This codec rework targets better bitrate control and encoding efficiency for Shorts.
September 2025
1 Commits • 1 Features
Sep 1, 2025September 2025: Focused AV1 encoder enhancement for Shorts in libsdl-org/aom. Introduced a new lt_coded_error statistic in first-pass encoding statistics to evaluate prediction error when using a long-term reference frame, updated accumulation/normalization to incorporate the metric, and integrated last2_frame as a potential long-term reference. This codec rework targets better bitrate control and encoding efficiency for Shorts.
July 2025
2 Commits
Jul 1, 2025July 2025 monthly summary for libsdl-org/aom focusing on chroma delta quantization handling bug fix in lossless vs real-time modes; two commits applied to stabilize behavior and associated test adjustments.
2 Commits
Jul 1, 2025July 2025 monthly summary for libsdl-org/aom focusing on chroma delta quantization handling bug fix in lossless vs real-time modes; two commits applied to stabilize behavior and associated test adjustments.
July 2025
May 2025
8 Commits • 4 Features
May 1, 2025May 2025 monthly summary for libsdl-org/aom focused on performance improvements for sharpness=3, adaptive RD tuning, high bit-depth variance stats, and robustness. Key outcomes include reduced compute load during transform search, adaptive temporal filtering, enhanced variance statistics for high bit-depth, and fixes to boundary handling and partition pruning to improve stability.
May 2025
8 Commits • 4 Features
May 1, 2025May 2025 monthly summary for libsdl-org/aom focused on performance improvements for sharpness=3, adaptive RD tuning, high bit-depth variance stats, and robustness. Key outcomes include reduced compute load during transform search, adaptive temporal filtering, enhanced variance statistics for high bit-depth, and fixes to boundary handling and partition pruning to improve stability.
April 2025
5 Commits • 1 Features
Apr 1, 2025April 2025 performance summary for libsdl-org/aom: Delivered major AV1 encoder quality and stability improvements with targeted commits, fixed critical constraint handling to prevent assertion failures, and addressed static-analysis warnings to improve maintainability. The work produced tangible business value through higher encoding quality, fewer edge-case failures, and clearer interfaces.
5 Commits • 1 Features
Apr 1, 2025April 2025 performance summary for libsdl-org/aom: Delivered major AV1 encoder quality and stability improvements with targeted commits, fixed critical constraint handling to prevent assertion failures, and addressed static-analysis warnings to improve maintainability. The work produced tangible business value through higher encoding quality, fewer edge-case failures, and clearer interfaces.
April 2025
March 2025
6 Commits • 2 Features
Mar 1, 2025March 2025 monthly summary for libsdl-org/aom focusing on sharpness-driven encoder improvements and test stabilization. Key contributions include implementing a sharpness-based encoder quantization with motion-vector range constraints, introducing sharpness-aware intra-mode search optimization, and stabilizing the sharpness test suite with thresholds adjustments. These changes collectively enhance encoding efficiency, reduce artifacts for sharper imagery, and improve test reliability and confidence in performance metrics.
March 2025
6 Commits • 2 Features
Mar 1, 2025March 2025 monthly summary for libsdl-org/aom focusing on sharpness-driven encoder improvements and test stabilization. Key contributions include implementing a sharpness-based encoder quantization with motion-vector range constraints, introducing sharpness-aware intra-mode search optimization, and stabilizing the sharpness test suite with thresholds adjustments. These changes collectively enhance encoding efficiency, reduce artifacts for sharper imagery, and improve test reliability and confidence in performance metrics.
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Quality Metrics
Correctness85.4%
Maintainability84.0%
Architecture80.6%
Performance75.6%
AI Usage20.0%
Skills & Technologies
Programming Languages
CC++
Technical Skills
AV1AV1 CodecAV1 codec developmentAlgorithm OptimizationBug FixingC ProgrammingC programmingC++Code AnalysisCode RefactoringCodec OptimizationImage ProcessingLossless CompressionLow-level OptimizationMotion Compensation
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