[FFmpeg-devel] [PATCH 2/3] lavc: replace ff_thread_get_buffer() with ff_get_buffer()
Anton Khirnov
anton at khirnov.net
Fri Mar 8 12:21:57 EET 2024
Quoting Andreas Rheinhardt (2024-03-08 11:19:59)
> Anton Khirnov:
> > Quoting Andreas Rheinhardt (2024-03-08 11:03:18)
> >> Anton Khirnov:
> >>> ff_thread_get_buffer() has exactly the same semantics as
> >>> ff_get_buffer(), except it is supposed to be used in frame-threaded
> >>> decoders. Since the decoder instance knows whether frame threading is in
> >>> use, there is no point in forcing decoder implementations to use a
> >>> different function merely because they happen to support frame
> >>> threading.
> >>> ---
> >>> libavcodec/aic.c | 4 ++--
> >>> libavcodec/alac.c | 4 ++--
> >>> libavcodec/av1dec.c | 2 +-
> >>> libavcodec/avcodec_internal.h | 13 +++++++++++++
> >>> libavcodec/bitpacked_dec.c | 4 ++--
> >>> libavcodec/cfhd.c | 4 ++--
> >>> libavcodec/cllc.c | 8 ++++----
> >>> libavcodec/cri.c | 2 +-
> >>> libavcodec/decode.c | 13 ++++++++++++-
> >>> libavcodec/dnxhddec.c | 2 +-
> >>> libavcodec/dvdec.c | 2 +-
> >>> libavcodec/dxtory.c | 12 ++++++------
> >>> libavcodec/dxv.c | 4 ++--
> >>> libavcodec/exr.c | 2 +-
> >>> libavcodec/flacdec.c | 4 ++--
> >>> libavcodec/fraps.c | 4 ++--
> >>> libavcodec/h264_slice.c | 2 +-
> >>> libavcodec/hapdec.c | 4 ++--
> >>> libavcodec/hdrdec.c | 2 +-
> >>> libavcodec/hevcdec.c | 2 +-
> >>> libavcodec/hqx.c | 4 ++--
> >>> libavcodec/huffyuvdec.c | 4 ++--
> >>> libavcodec/jpeg2000dec.c | 2 +-
> >>> libavcodec/lagarith.c | 12 ++++++------
> >>> libavcodec/lcldec.c | 4 ++--
> >>> libavcodec/magicyuv.c | 2 +-
> >>> libavcodec/mdec.c | 4 ++--
> >>> libavcodec/notchlc.c | 2 +-
> >>> libavcodec/photocd.c | 2 +-
> >>> libavcodec/pixlet.c | 2 +-
> >>> libavcodec/pngdec.c | 4 ++--
> >>> libavcodec/proresdec2.c | 2 +-
> >>> libavcodec/pthread_frame.c | 7 ++-----
> >>> libavcodec/qoidec.c | 2 +-
> >>> libavcodec/rtv1.c | 2 +-
> >>> libavcodec/sheervideo.c | 4 ++--
> >>> libavcodec/takdec.c | 5 +++--
> >>> libavcodec/thread.h | 10 ----------
> >>> libavcodec/tiff.c | 2 +-
> >>> libavcodec/tta.c | 4 ++--
> >>> libavcodec/utils.c | 5 -----
> >>> libavcodec/utvideodec.c | 4 ++--
> >>> libavcodec/v210dec.c | 4 ++--
> >>> libavcodec/v410dec.c | 4 ++--
> >>> libavcodec/vaapi_av1.c | 4 ++--
> >>> libavcodec/vble.c | 4 ++--
> >>> libavcodec/vmixdec.c | 2 +-
> >>> libavcodec/vvc/vvc_refs.c | 4 ++--
> >>> libavcodec/wbmpdec.c | 2 +-
> >>> libavcodec/webp.c | 2 +-
> >>> libavcodec/ylc.c | 4 ++--
> >>> 51 files changed, 110 insertions(+), 103 deletions(-)
> >>>
> >>
> >> -1: This adds avoidable runtime checks.
> >
> > What checks and why is that a problem?
> >
> It adds a runtime check to every call to ff_get_buffer() by every
> decoder not supporting frame-threading (by checking whether
> frame-threading is currently in use).
I cannot imagine any situation where it could have a measurable impact.
> Every avoidable runtime check should always be avoided.
Premature optimization is the root of all evil.
--
Anton Khirnov
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