While the VideoLAN developers are busy these days working on [1]dav2d for AV2 video decoding, they haven't let up work on dav1d and recently released dav1d 1.5.4 for continuing to enhance this leading open-source, CPU-based AV1 decoder.

With dav1d 1.5.4 they have introduced support foir OS/2. Dav1d to the OS/2 operating system ended up being a fairly easy port with just Meson build system and header file changes.

Dav1d 1.5.4 also adds Armv9.3-A Guarded Control Stack "GCS" support, AArch64 optimizations, RISC-V optimizations, portability improvements for non-POSIX systems, and other updates.

- Support for OS/2, including API exports and assembly

- Switch to external checkasm

- Add Armv9.3-A GCS (Guarded Control Stack) support

- AArch64: optimize ipred_v, ipred_h and ipred_smooth_* 8bpc functions, and reduce .text size

- ARM32: optimize prep_neon

- RISC-V: ipred_(dc, h, v, pal) optimizations for 8 and 16bpc, generate_grain_y for 8bpc, and optimizations (prep/put_8tap, 6-tap and copy paths)

- Portability improvements for non-POSIX systems (signal() fallback)

- Schedule tile tasks for all passes at once, improving threading

- Precompute the quantization matrix tables at build time

- Move loop-invariant computations out of hot loops

Dav1d 1.5.4 can be downloaded at [2]VideoLAN.org .



[1] https://www.phoronix.com/search/dav2d

[2] https://code.videolan.org/videolan/dav1d/-/releases/1.5.4