build fails with ffmpeg 8.0 and vdpau

[plorenzo]

Hi,

mplayer fails to build with ffmpeg 8.0 (and Debian is about to introduce it); I've tested patches from the devel list
​https://lists.mplayerhq.hu/pipermail/mplayer-dev-eng/2025-May/074270.html
and it builds fine with vdpau disabled;
(note that Debian version svn38674 is misleading, for testing I've included svn38675-76-77 and the patch from the list)

with vdpau enabled I have the following errors:

libmpcodecs/ad_spdif.c: In function 'control':
libmpcodecs/ad_spdif.c:274:51: warning: unused parameter 'arg' [-Wunused-parameter]
  274 | static int control(sh_audio_t *sh, int cmd, void* arg, ...)
      |                                             ~~~~~~^~~
libmpcodecs/vd_ffmpeg.c: In function 'vdpau_render_wrapper':
libmpcodecs/vd_ffmpeg.c:213:20: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  213 |     data.surface = (VdpVideoSurface)mpi->priv;
      |                    ^
libmpcodecs/vd_ffmpeg.c: In function 'set_format_params':
libmpcodecs/vd_ffmpeg.c:287:45: error: implicit declaration of function 'av_alloc_vdpaucontext' [-Wimplicit-function-declaration]
  287 |             avctx->hwaccel_context = vdpc = av_alloc_vdpaucontext();
      |                                             ^~~~~~~~~~~~~~~~~~~~~
libmpcodecs/vd_ffmpeg.c:287:43: error: assignment to 'AVVDPAUContext *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
  287 |             avctx->hwaccel_context = vdpc = av_alloc_vdpaucontext();
      |                                           ^
libmpcodecs/vd_ffmpeg.c: In function 'init':
libmpcodecs/vd_ffmpeg.c:325:16: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
  325 |     lavc_codec = avcodec_find_decoder_by_name(codec_idx2str(sh->codec->dll_idx));
      |                ^
libmpcodecs/vd_ffmpeg.c:417:41: warning: comparison of integer expressions of different signedness: 'int' and 'long unsigned int' [-Wsign-compare]
  417 |         if (!sh->bih || sh->bih->biSize <= sizeof(*sh->bih))

Lorenzo