[FFmpeg-devel] [PATCH] qsv: add requirement for the mininal version of libmfx

[Xiang, Haihao]

On Wed, 2022-05-25 at 12:22 -0400, Leo Izen wrote:
> 
> On 5/25/22 12:05, Timo Rothenpieler wrote:
> > 
> > 
> > On 22/05/2022 14:19, Haihao Xiang wrote:
> > > libmfx 1.28 was released 3 years ago, it is easy to get a greater
> > > version than 1.28. We may remove lots of compile-time checks if adding
> > > the requirement for the minimal version in the configure script.
> > > ---
> > >   configure                  |   7 +-
> > >   libavcodec/qsv.c           |  24 --
> > >   libavcodec/qsvenc.c        | 471 +++++++++++++------------------------
> > >   libavcodec/qsvenc.h        |  51 +---
> > >   libavcodec/qsvenc_h264.c   |   6 -
> > >   libavcodec/qsvenc_hevc.c   |  10 -
> > >   libavfilter/vf_scale_qsv.c |  13 +-
> > >   libavfilter/vf_vpp_qsv.c   | 143 ++++++-----
> > >   libavutil/hwcontext_qsv.c  |   2 -
> > >   9 files changed, 249 insertions(+), 478 deletions(-)
> > > 
> > > diff --git a/configure b/configure
> > > index f115b21064..2337f0a8f2 100755
> > > --- a/configure
> > > +++ b/configure
> > > @@ -6566,8 +6566,11 @@ enabled liblensfun        && require_pkg_config 
> > > liblensfun lensfun lensfun.h lf_
> > >   # Media SDK or Intel Media Server Studio, these don't come with
> > >   # pkg-config support.  Instead, users should make sure that the build
> > >   # can find the libraries and headers through other means.
> > > -enabled libmfx            && { check_pkg_config libmfx libmfx 
> > > "mfx/mfxvideo.h" MFXInit ||
> > > -                               { require libmfx "mfx/mfxvideo.h" 
> > > MFXInit "-llibmfx $advapi32_extralibs" && warn "using libmfx without 
> > > pkg-config"; } }
> > > +enabled libmfx            && { check_pkg_config libmfx "mfx >= 1.28" 
> > > "mfx/mfxvideo.h" MFXInit ||
> > > +                               { require libmfx "mfx/mfxvideo.h 
> > > mfx/mfxdefs.h" MFXInit "-llibmfx $advapi32_extralibs" &&
> > 
> > This broke build with mfx_dispatch. Before this, it checked for 
> > libmfx.pc. Now it checks for mfx.pc, which is not installed by it.
> > 
> > Which of those is correct? It should definitely not drop support for 
> > libmfx.pc, which was checked before this.
> 
> It also attempts to link to -llibmfx, which means liblibmfx.so. I'm 
> guessing it's supposed to link to -lmfx instead.

It is -llibmfx in the original code. Please see commit
164e2773261451ef33c4616296ec5bebecff42af for why it is -llibmfx instead of -lmfx
here.

Thanks
Haihao