Feature Request: sr_amf + amf_hqscaler + amf_vqenhance

See FFmpeg's AMF filters (5.3: https://trac.ffmpeg.org/wiki/Hardware/AMF) — sr_amf / super-resolution scaling. Would be a nice addition to the already-implemented amf_frc. Since the infrastructure already exists in video/filter/vf_amf.c, amf_hqscaler (HQScaler / VideoSR super-resolution) and amf_vqenhance (VQ Enhancer) should fit he same bucket Edit: amf_hqscaler already exists — it's sr_amf.