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GPUOpen-LibrariesAndSDKs / AMF

The Advanced Media Framework (AMF) SDK provides developers with optimal access to AMD devices for multimedia processing
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Conflicting documentation: HEVC pre-analysis #395

Open Chipcraft opened 1 year ago

Chipcraft commented 1 year ago

AMF 1.4.29 /components/VideoEncoderHEVC.h comment for pre-analysis states: _"Currently only works in AMF_VIDEO_ENCODER_HEVC_RATE_CONTROL_METHOD_PEAK_CONSTRAINEDVBR mode. Refer to AMF Video PreAnalysis API reference for more details."

Meanwhile, /doc/AMF_Video_Encode_HEVCAPI.pdf states: "QVBR, HQVBR and HQCBR are only supported if PreAnalysis is enabled."_

So the question is, which one is it?

Also, the document which is supposed to provide additional information on the subject (AMF Video PreAnalysis API) doesn't even mention the rate control modes, or the potential restrictions related to them.

DimkaTsv commented 1 year ago

Well, from my personal investigation... QVBR, HQVBR and HQCBR all force enable preanalysis just by being used (they don't work without it). but default lookahead value is small (1). But idk about other stuff. Not sure if CBR of CQP actually utilize preanalysis at all... So from common modes only VBR benefits from it noticeably.