SVT-AV1-4.0.0

[Bruce Dubbs]

New major version.

[Joe Locash]

This is a release candidate.

[Bruce Dubbs]

It looks like the stable release is available now: ​https://gitlab.com/AOMediaCodec/SVT-AV1/-/releases

[Joe Locash]

This breaks the build of ffmpeg. Upstream ffmpeg commit that fixes it: ​https://git.ffmpeg.org/gitweb/ffmpeg.git/commit/a5d4c398b411a00ac09d8fe3b66117222323844c

[Bruce Dubbs]

For us it looks like a sed will do:

sed -i '/adaptive/i param->aq_mode = 0;' libavcodec/libsvtav1.c

if we care about alignment in the code, then use:

   '/adaptive/i\       param->aq_mode = 0;'

that's 8 spaces.

[Bruce Dubbs]

[4.0.0] - 2026-01-13

API updates

• Added support for setting a custom global logger for library consumers (!2570, !2579)
• Cleaned up public API headers including removal of deprecated macros, structs, and fields (!2565, !2568)
  • Additionally cleaned up anything marked using SVT_AV1_CHECK_VERSION().
• Added ability to calculate per-frame PSNR and SSIM metrics (!2521)
• Allow sending more than 1 but less than 4 frames with avif mode (This is not for AVIF image sequence, but for encoding an alpha layer) (!2551, !2560)

Encoder

• Added dynamic delta q res switching (SVT-AV1-PSY, !2484, !2504)
• Added new or ported Arm optimizations for various functions (!2478, !2486, !2479, !2497, !2495, !2516, !2519, !2493, !2529, !2531, !2530, !2540, !2541, !2548, !2555, !2553)
• New s-frame QP and QP-offset options (!2477)
• New s-frame mode for setting s-frames at specific positions in decode order (!2523, !2534)
• Ported over intraBC hash search optimizations from libaom (SVT-AV1-PSY, !2491)
• Added togglable adaptive film grain (SVT-AV1-PSY, !2496)
• Added SIMD optimization for memcpy and memset functions for Neon (!2498)
• Added an Image Quality (IQ) tune (SVT-AV1-PSY, !2489, !2514, !2562, !2561)
• Added an option to allow restricting selection of block transforms (SVT-AV1-PSY, !2507, !2576)
• Reduced runtime memory usage for RTC mode (!2505)
• Added extended quarter-step CRF support (SVT-AV1-PSY, !2503, !2522)
• Added --scm 3 for better screen content detection (SVT-AV1-PSY, !2494, !2559)
• Added CMake configuration file for finding SVT-AV1 package (!2517, !2537)
• Visually improved the detailed progress mode output (SVT-AV1-PSY, !2511)
• Added AC Bias (SVT-AV1-PSY, !2513, !2574)
• Tune lambda-weights for intra frames with high QPs (!2543)
• Still image algorithmic and performance improvements (!2552, !2567)
• RTC mode optimization and preset tuning for all modes (!2558)

Cleanups, bug fixes, and Documentation

In addition to the cleanups mentioned in the API section,

• Code specific cleanup for slimmer binary sizes (!2476)
• Minor CMake build related fixes (!2501)
• Fixed RTC build with unit tests (!2499)
• Changed tune value from integer to enum for better readability (!2506)
• Fixed an issue with the encoder hanging when given an input with a height of 24 pixels or less (!2518)
• Fixed compilation warnings for GCC 15 with Arm (!2525)
• Fixed a bug that results in encoding an invalid bitstream when using rtc with a high QP value (!2502)
• Added CI coverage for compiling FFmpeg on macOS Arm (!2536)
• Fixed a hang with VBR encoding (!2300, !2535)
• Reject inputs with an FPS less than 1 as unsupported, removed --fps argument (!2305, !2542, !2546)
• Fixed a hang when using recon output with low delay mode (!2315, !2544)
• Fixed an encoder crash when using RTC with resolutions not divisible by 16 and presets >= 11 (!2301, !2547)
• Added a python based testing framework for comparing codec performance and quality (!2532, !2550, !2556, !2563, !2564, !2566)
• Addressed a partial amount of cppcheck warnings from the version bundled with Ubuntu 24.04 (!2512)
• Fixed a CMake issue when using build.bat and Ninja on Windows (!2569)
• Fixed some compilation and linking issues with Emscripten (!2571)
• Fixed a hang caused by changes in !2452 (!2318, !2572)
• Fixed bitstream level tier compliance with AV1 specification (!2332, !2577, !2581, !2587)
• Removed in-tree gstreamer pluigin (!2586)
• Unit test bug fixes (!2500, !2527, !2549, !2573, !2575)
• General code cleanup and bugfixes (!2524, !2510, !2520, !2528, !2538, !2557, !2582, !2584)
• General documentation and console output changes (!2515, !2508, !2533, !2545, !2554, !2583)

[Bruce Dubbs]

For ffmpeg I ended up using:

sed -e '/adaptive/c\ param->aq_mode = 0;' \
    -i libavcodec/libsvtav1.c

[Bruce Dubbs]

Fixed at commits:

958ce19aaf Update to Linux-PAM-1.7.2.
5c02e408f7 Update to SVT-AV1-v4.0.0.

[Bruce Dubbs]

Milestone renamed