ManagedCodecs 0.2.1

Faster HE-AAC (the QMF banks by smaller transforms) and CABAC H.264, and memory management operation 5 in H.264 field
pictures. The public API is that of 0.2.0, unchanged.

Added

• H.264: memory management operation 5 in field pictures, which threw NotSupportedException.

Changed

• HE-AAC decodes faster: the full QMF synthesis bank takes two DCT-IVs of 64 points, each by a complex FFT of 32, where
  it took a complex FFT of 128, and the analysis bank a complex FFT of 32 for its 64 real values, where it took one of
  64, both with their twiddles in vectors. Together 14 to 16% faster on 5.1 HE-AAC and 8 to 10% on HE-AAC v2, on
  GitHub's x64 and ARM64 runners (compare.yml); the output moves only in its last bits (to 1e-12 of the peak).
• H.264 decodes CABAC streams faster: the deblocking filter's edge strengths of bi-predicted blocks in vectors, CABAC's
  context selection reading neighbours inside the macroblock directly, and its significance map without per-bin
  bounds checks. About 3% fewer instructions a frame on CABAC streams with B frames, 1 to 2% faster on the cloud VM
  measured (docs/notes/h264-speed-gap-2026-10.md); CAVLC streams are unchanged; the output is the same.