mpv-fourier: iter2 — wire v4l2request hwdec through drmprime VO

Adds Kwiboo / Langdale's 2024-08 patches (0001-meson + 0002-vo-hwdec-drmprime)
so AV_HWDEVICE_TYPE_V4L2REQUEST flows through mpv's drmprime VO hwdec and
`--hwdec=v4l2request` engages against the dmabuf-wayland VO instead of failing
with "Could not create device". The matcher previously filtered on
AV_HWDEVICE_TYPE_DRM and rejected v4l2request even when libavcodec's hwaccel
returned a valid PRIME descriptor.

PKGBUILD: pkgrel 9 → 10, source[] picks up both new patches, prepare() applies
them before the existing 0001-vo_dmabuf_wayland cache-sync workaround,
meson build flag -Dv4l2request=enabled added so the new option compiles in.

Stacks on top of iter1 (713a856): the dma_buf cache-sync workaround stays
load-bearing for the existing vaapi_dmabuf and drmprime_dmabuf import paths;
this iter only adds the wiring for the drmprime VO's hwdec selector.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

arch/mpv-fourier/PKGBUILD

@@ -23,8 +23,8 @@ pkgname=mpv-fourier
 _upstreampkg=mpv
 epoch=1
 pkgver=0.41.0
-pkgrel=9
-pkgdesc='mpv with fourier-umbrella patches (vo_dmabuf_wayland explicit cache-sync workaround)'
+pkgrel=10
+pkgdesc='mpv with fourier-umbrella patches (vo_dmabuf_wayland explicit cache-sync workaround + v4l2request hwdec wiring)'
 arch=('aarch64')
 url='https://mpv.io/'
 license=('GPL-2.0-or-later AND LGPL-2.1-or-later')
@@ -49,16 +49,28 @@ options=('!emptydirs')
 
 source=(
     "${_upstreampkg}-${pkgver}.tar.gz::https://github.com/mpv-player/${_upstreampkg}/archive/v${pkgver}/${_upstreampkg}-${pkgver}.tar.gz"
+    # Kwiboo + Langdale: wire AV_HWDEVICE_TYPE_V4L2REQUEST through mpv's drmprime VO hwdec
+    '0001-meson-add-detection-logic-for-v4l2request-support.patch'
+    '0002-vo-hwdec-drmprime-add-separate-hwdecs-for-v4l2reques.patch'
     '0001-vo_dmabuf_wayland-explicit-cache-sync-on-import-fd.patch'
 )
 sha256sums=(
     'ee21092a5ee427353392360929dc64645c54479aefdb5babc5cfbb5fad626209'
+    '302dc2a89f1dc3efb8fd7a035fd70bee4b343acf01fe78b294e8aeca0b221dc2'
+    'b6a71030017867c84692a8a198f9db143ce8394ab5a6ed3c705ea2d715d525fc'
     '6c929bea7636b8d81b63a1275ba1d8a471fe2f249fc23509043ace6cf9b076a7'
 )
 
 prepare() {
     cd "${_upstreampkg}-${pkgver}"
 
+    # Kwiboo + Langdale (2024-08): wire AV_HWDEVICE_TYPE_V4L2REQUEST through
+    # the drmprime VO hwdec so --hwdec=v4l2request engages on dmabuf-wayland.
+    # Without these, mpv reports "Could not create device" because the matcher
+    # filters by lavc_device type and v4l2request != AV_HWDEVICE_TYPE_DRM.
+    patch -p1 < "${srcdir}/0001-meson-add-detection-logic-for-v4l2request-support.patch"
+    patch -p1 < "${srcdir}/0002-vo-hwdec-drmprime-add-separate-hwdecs-for-v4l2reques.patch"
+
     # iter1 of dmabuf-modifier-triage — explicit DMA_BUF_IOCTL_SYNC on import
     # fds in vaapi_dmabuf_importer + drmprime_dmabuf_importer. Workaround for
     # missing implicit-fence on V4L2 stateless CAPTURE buffers; root cause is
@@ -70,6 +82,7 @@ build() {
     local _meson_options=(
         --auto-features auto
 
+        -Dv4l2request=enabled
         -Dlibmpv=true
         -Dgl-x11=enabled
         -Dcaca=disabled