@galad87 VTRegisterSupplementalVideoDecoderIfAvailable() only available on macOS. But calling this func on my M1 Pro machine will add VP9 to supported list, but AV1 will be still unavailable

Do you convert the NAL start code to the MPEG format? Specifically, from the start code (0001) to a 4-byte NAL unit size? VideoToolbox specifically requires 4-byte size instead of start code