Month: 2026-03 | Repository: libsdl-org/aom Overview: Delivered reliability, performance, and stability improvements across the aom library. Focus areas included deprecation with test updates, encoding efficiency and real-time performance, and robustness of frame scaling and mask-prediction paths. These changes improve maintainability, reduce production risks, and enable more efficient encodes in real-world workloads. Key features delivered: - Deprecation of fixed_qp_offsets and test reliability: deprecates the fixed_qp_offsets array and updates tests to ensure proper configuration handling, improving long-term maintainability. Commits: c67aaceba3e32e668f633c9fc3cba5f94badd834; 288ad69242232a60dac6dca5697cb0154a7f39dc - Real-time encoding optimization: optimize encoding for real-time scenarios to reduce file sizes while preserving quality. Commits: e7837adfe8d62f58dab48f991f93805d9d220f6c - Encoding efficiency improvements: improve inter-frame encoding and cost handling for layered images; tuning IQ and SSIMULACRA2. Commits: 4265e4aa4b4ee9de380f3f8a82c74438cd5f2acf; 9856078eebb7112643fda85f4493c068938280bb - Frame scaling crash fixes and robustness: fix multiple crash-related issues in the frame scaling path (loop restoration, upsampled prediction calls, worker synchronization) and add unit tests. Commits: 1c03b6d9ef8f29124f5e1519a13f094c547960fa; 62755547c5ec954832515ad643e92e834d862785; 74aaa1eff111badcfd471748ed790a5a9cc8cb23; 4cc0867f261f46d00b2ddb27b4de70d8e8e4552e; bdd1dc58422459e90ad5eb7de0eeddfa8e884270 - Compound mask prediction resize crash tests: add tests to prevent crashes related to compound mask prediction during resize operations, improving stability. Commits: cb3cfa13cc61751ce21dafe725c2135589e7b351; f9533e48f5e5f081d9598b62fc43780bf717037b Major bugs fixed: - Resolved frame scaling path crashes and instability across multiple scenarios, including loop restoration and comp_mask_upsampled_pred paths. - Added targeted unit tests to verify fixes and prevent regressions in frame scaling and resize-related crash scenarios. Overall impact and accomplishments: - Significantly improved runtime stability and reliability of the encoder, reducing crash surface in production workflows. - Improved long-term maintainability by deprecating deprecated configuration and ensuring tests cover configuration handling. - Achieved meaningful encoding efficiency gains and real-time mode optimizations, contributing to smaller file sizes without sacrificing perceptual quality. - Strengthened quality assurance with added unit tests around frame scaling and mask-prediction paths, decreasing regression risk. Technologies/skills demonstrated: - C/C++ optimization and tuning, AV1 encoder internals, inter-frame and real-time encoding strategies. - Performance measurement and iteration (tuning IQ/SSIMULACRA2, real-time mode deductions). - Test-driven development, regression testing, and robust unit test coverage for edge-case scenarios. - Change management and documentation (CHANGELOG updates and commit traceability).

February 2026 monthly performance summary focusing on delivering encoding stability, tuning enhancements, and developer experience across libsdl-org/libavif and libsdl-org/aom. Key outcomes include cross-frame consistency for AVIF tuning, expanded tuning modes and inter-frame support, and improved control over QP and encoding efficiency. The work emphasizes business value through reliability, performance, and better API/documentation for downstream users.

January 2026: Delivered targeted encoding and scoring efficiency improvements across two SDL repositories. Implemented all-intra encoding for two-layer images in the libavif module, reducing file size and improving encoding efficiency when the first layer has very low quality. In the aom module, improved SSIMULACRA 2 scoring efficiency by tuning quantization parameter formulas and boosting chroma delta for 4:2:0 subsampling, delivering measurable score gains and more stable 10th percentile performance. These efforts contribute to lower storage and bandwidth costs, faster encoding pipelines, and improved perceptual quality at similar bitrates. All changes are traceable to commit-level changes and were benchmarked against established datasets (e.g., the Daala subset1).

December 2025 performance highlights across libsdl-org/aom and libsdl-org/libavif. Delivered measurable decoding efficiency gains in AOM and reworked encoder quality controls in AVIF, aligning with speed and quality targets for faster delivery and predictable file sizes. Validated through benchmarking and code-review-driven refinements; linked to bug aomedia:463698815.

November 2025 performance-focused update for libsdl-org/aom: Delivered targeted AV1 decode/encode improvements and stability fixes with measurable business value.

September 2025: Delivered a targeted documentation clarification for aom_hadamard_4x4_c(), aligning dynamic range and bit-depth notes with the actual implementation for 8-bit and high bit-depth buffers. This alignment reduces onboarding time, minimizes downstream integration risk, and improves long-term maintainability in the libsdl-org/aom module.

August 2025 monthly summary for libsdl-org/aom focusing on intraBC search space optimization for encoding efficiency. Key contributions include prioritizing hash-based searches over pixel-based searches, conditional skipping of pixel searches based on hash results, and refining search strategy for different block sizes to boost encoding efficiency. The work is captured in commit 9c5eba5dd892b1fec197295a0ea8cddfcd59bf85.

July 2025 monthly summary for libsdl-org/aom: Key features delivered and maintenance work across intra-block copy (intraBC), screen content detection (SCD mode 2), adaptive sharpness with SSIMULACRA2 tuning, and Variance Boost strength. Focused on reducing encoding time, improving detection speed/accuracy, and enhancing visual quality, while laying groundwork for image-focused tunings. This work strengthens performance, quality, and tunability across the encoder stack.

June 2025 monthly summary for libsdl-org/aom focusing on performance optimization and bug fixes. Highlights include refactoring discount_color_cost into a separate speed feature and tuning CPU-used 8 to balance speed and BD-rate for intra modes; a palette mode overuse fix with changelog updates clarifying BD-rate gains at speeds 8 and 9; overall impact includes improved encoding speed/efficiency and clearer release messaging.

In May 2025, delivered three key encoder enhancements in libsdl-org/aom that improve screen content handling, non-RD performance, and all-intra quality. The work focused on expanding AV1 encoder capabilities with targeted optimizations that drive better compression efficiency and visual quality for screen-heavy content, while maintaining performance.

March 2025 monthly recap focused on enhancing AOM encoder tuning controls in libsdl-org/aom to improve perceptual quality and tuning flexibility. Key changes introduce a dedicated --tune=ssimulacra2 option for optimizing SSIMULACRA 2 scores in all-intra mode and refine --tune=iq behavior to use the all-intra luma QM level formula, coexisting with the existing AOM_TUNE_IQ setting. These changes provide finer control over encoding quality without breaking existing configurations, enabling better targeting of perceptual metrics across content pipelines.

December 2024 (2024-12) — The libsdl-org/aom work focused on encoding efficiency and perceptual quality improvements through targeted tuning across AV1 variance sampling, luma quantization, CDEF strength behavior, and chroma quantization, delivering more efficient bitrates and higher perceptual quality for challenging content such as mixed-variance blocks and 4:2:2 material. Value was unlocked by refining tuning parameters and clarifying intra-mode behavior, enabling better tradeoffs between noise reduction, sharpness, and compression efficiency. Key outcomes include: higher encoding efficiency and improved visual quality in AV1 encoding; better SSIMULACRA2 alignment through luma/chroma quantization adjustments; more flexible and predictable CDEF strength handling in all-intra scenarios; and improved 4:2:2 chroma allocation under simulacra2 tuning. This work demonstrates strong proficiency in video encoding optimization (AV1, CDEF, QM), tuning for perceptual metrics (SSIMULACRA2), and maintainability through clearer comments and documented intent.

November 2024 monthly performance snapshot for libsdl-org/aom focused on delivering high-quality AV1 encoding features, expanding test coverage, and maintaining repository hygiene. The work enabled tangible improvements in visual quality, configurability, and reliability, while keeping a clean codebase for faster iteration.

For 2024-10, libsdl-org/aom delivered targeted feature work around All-Intra mode quality and improved documentation, emphasizing business value and long-term maintainability. Key outcomes include improved encoding quality for low- to mid-quality encodes through QM tuning and adaptive CDEF, plus clarifications and rationale around all-intra configuration to streamline future maintenance. There were no major bugs fixed in this period for this repo; efforts focused on delivering high-impact features and ensuring codebase clarity. The work demonstrates proficiency in AV1 codec tuning, CDEF configuration, and high-quality code/documentation practices.