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/0001-meson-add-detection-logic-for-v4l2request-support.patch

@@ -0,0 +1,56 @@
+From 9d3bbd3651eb8405b8609e4f5e8c4978056483d0 Mon Sep 17 00:00:00 2001
+From: Jonas Karlman <jonas@kwiboo.se>
+Date: Sun, 18 Aug 2024 17:42:14 -0700
+Subject: [PATCH 1/2] meson: add detection logic for v4l2request support
+
+We will probably adjust this to look for a specific libavutil version after
+v4l2request support is merged upstream, but this check is fine for now.
+---
+ meson.build   | 11 +++++++++++
+ meson.options |  1 +
+ 2 files changed, 12 insertions(+)
+
+diff --git a/meson.build b/meson.build
+index d4c75a907f..540f279dc7 100644
+--- a/meson.build
++++ b/meson.build
+@@ -1444,6 +1444,16 @@ if features['ios-gl']
+     sources += files('video/out/hwdec/hwdec_ios_gl.m')
+ endif
+ 
++v4l2request = get_option('v4l2request').require(
++    cc.has_header_symbol('libavutil/hwcontext.h',
++                         'AV_HWDEVICE_TYPE_V4L2REQUEST',
++                         dependencies: libavutil)
++)
++features += {'v4l2request': v4l2request.allowed()}
++if features['v4l2request']
++    sources += files('video/v4l2request.c')
++endif
++
+ libva = dependency('libva', version: '>= 1.1.0', required: get_option('vaapi'))
+ 
+ vaapi_drm = dependency('libva-drm', version: '>= 1.1.0', required:
+@@ -1911,6 +1921,7 @@ summary({'cocoa': features['cocoa'] and features['swift'],
+          'libmpv': get_option('libmpv'),
+          'lua': features['lua'],
+          'opengl': features['gl'],
++         'v4l2request': features['v4l2request'],
+          'vulkan': features['vulkan'],
+          'wayland': features['wayland'],
+          'x11': features['x11']},
+diff --git a/meson.options b/meson.options
+index 836d16d03f..54ec2dccfc 100644
+--- a/meson.options
++++ b/meson.options
+@@ -103,6 +103,7 @@ option('d3d-hwaccel', type: 'feature', value: 'auto', description: 'D3D11VA hwac
+ option('d3d9-hwaccel', type: 'feature', value: 'auto', description: 'DXVA2 hwaccel')
+ option('gl-dxinterop-d3d9', type: 'feature', value: 'auto', description: 'OpenGL/DirectX DXVA2 hwaccel')
+ option('ios-gl', type: 'feature', value: 'auto', description: 'iOS OpenGL ES interop support')
++option('v4l2request', type: 'feature', value: 'auto', description: 'V4L2 Request API hwaccel')
+ option('videotoolbox-gl', type: 'feature', value: 'auto', description: 'Videotoolbox with OpenGL')
+ option('videotoolbox-pl', type: 'feature', value: 'auto', description: 'Videotoolbox with libplacebo')
+ 
+-- 
+2.52.0
+

arch/mpv-fourier/0002-vo-hwdec-drmprime-add-separate-hwdecs-for-v4l2reques.patch

@@ -0,0 +1,435 @@
+From dd1e1fd6fe884d66c49dc26af715e1423c7471a3 Mon Sep 17 00:00:00 2001
+From: Philip Langdale <philipl@overt.org>
+Date: Sun, 18 Aug 2024 17:43:41 -0700
+Subject: [PATCH 2/2] vo: hwdec: drmprime: add separate hwdecs for v4l2request
+
+With all the machinery in place, we can now add the v4l2request hwdecs with a
+different hw device type, and a different initialisation path. This applies to
+both the drmprime and drmprime_overlay hwdecs.
+
+At the moment, the device initialisation is done in the bare minimum way, but
+it can be extended to take a device path (for example) if that makes sense as
+we better understand what meaningful configuration will be.
+
+Co-authored-by: Jonas Karlman <jonas@kwiboo.se>
+---
+ video/hwdec.c                            |   3 +
+ video/hwdec.h                            |   1 +
+ video/out/gpu/hwdec.c                    |   6 ++
+ video/out/hwdec/hwdec_drmprime.c         | 125 +++++++++++++++++------
+ video/out/hwdec/hwdec_drmprime_overlay.c |  81 +++++++++++++--
+ video/out/vo_dmabuf_wayland.c            |   1 +
+ video/v4l2request.c                      |  34 ++++++
+ 7 files changed, 210 insertions(+), 41 deletions(-)
+ create mode 100644 video/v4l2request.c
+
+diff --git a/video/hwdec.c b/video/hwdec.c
+index deba518e82..de2ffecc40 100644
+--- a/video/hwdec.c
++++ b/video/hwdec.c
+@@ -125,6 +125,9 @@ static const struct hwcontext_fns *const hwcontext_fns[] = {
+ #if HAVE_DRM
+     &hwcontext_fns_drmprime,
+ #endif
++#if HAVE_V4L2REQUEST
++    &hwcontext_fns_v4l2request,
++#endif
+ #if HAVE_VAAPI
+     &hwcontext_fns_vaapi,
+ #endif
+diff --git a/video/hwdec.h b/video/hwdec.h
+index e7734e5d7e..bf337389cb 100644
+--- a/video/hwdec.h
++++ b/video/hwdec.h
+@@ -119,6 +119,7 @@ extern const struct hwcontext_fns hwcontext_fns_cuda;
+ extern const struct hwcontext_fns hwcontext_fns_d3d11;
+ extern const struct hwcontext_fns hwcontext_fns_drmprime;
+ extern const struct hwcontext_fns hwcontext_fns_dxva2;
++extern const struct hwcontext_fns hwcontext_fns_v4l2request;
+ extern const struct hwcontext_fns hwcontext_fns_vaapi;
+ extern const struct hwcontext_fns hwcontext_fns_vdpau;
+ 
+diff --git a/video/out/gpu/hwdec.c b/video/out/gpu/hwdec.c
+index be39c507d0..f50b927851 100644
+--- a/video/out/gpu/hwdec.c
++++ b/video/out/gpu/hwdec.c
+@@ -38,6 +38,8 @@ extern const struct ra_hwdec_driver ra_hwdec_drmprime;
+ extern const struct ra_hwdec_driver ra_hwdec_drmprime_overlay;
+ extern const struct ra_hwdec_driver ra_hwdec_aimagereader;
+ extern const struct ra_hwdec_driver ra_hwdec_vulkan;
++extern const struct ra_hwdec_driver ra_hwdec_v4l2request;
++extern const struct ra_hwdec_driver ra_hwdec_v4l2request_overlay;
+ 
+ const struct ra_hwdec_driver *const ra_hwdec_drivers[] = {
+ #if HAVE_D3D_HWACCEL
+@@ -73,6 +75,10 @@ const struct ra_hwdec_driver *const ra_hwdec_drivers[] = {
+     &ra_hwdec_drmprime,
+     &ra_hwdec_drmprime_overlay,
+ #endif
++#if HAVE_V4L2REQUEST
++    &ra_hwdec_v4l2request,
++    &ra_hwdec_v4l2request_overlay,
++#endif
+ #if HAVE_ANDROID_MEDIA_NDK
+     &ra_hwdec_aimagereader,
+ #endif
+diff --git a/video/out/hwdec/hwdec_drmprime.c b/video/out/hwdec/hwdec_drmprime.c
+index 7869eb124a..446f63de44 100644
+--- a/video/out/hwdec/hwdec_drmprime.c
++++ b/video/out/hwdec/hwdec_drmprime.c
+@@ -77,7 +77,7 @@ static const char *forked_pix_fmt_names[] = {
+     "rpi4_10",
+ };
+ 
+-static int init(struct ra_hwdec *hw)
++static int pre_init(struct ra_hwdec *hw)
+ {
+     struct priv_owner *p = hw->priv;
+ 
+@@ -92,36 +92,12 @@ static int init(struct ra_hwdec *hw)
+         return -1;
+     }
+ 
+-    /*
+-     * The drm_params resource is not provided when using X11 or Wayland, but
+-     * there are extensions that supposedly provide this information from the
+-     * drivers. Not properly documented. Of course.
+-     */
+-    mpv_opengl_drm_params_v2 *params = ra_get_native_resource(hw->ra_ctx->ra,
+-                                                              "drm_params_v2");
+-
+-    /*
+-     * Respect drm_device option, so there is a way to control this when not
+-     * using a DRM gpu context. If drm_params_v2 are present, they will already
+-     * respect this option.
+-     */
+-    void *tmp = talloc_new(NULL);
+-    struct drm_opts *drm_opts = mp_get_config_group(tmp, hw->global, &drm_conf);
+-    const char *opt_path = drm_opts->device_path;
+-
+-    const char *device_path = params && params->render_fd > -1 ?
+-                              drmGetRenderDeviceNameFromFd(params->render_fd) :
+-                              opt_path ? opt_path : "/dev/dri/renderD128";
+-    MP_VERBOSE(hw, "Using DRM device: %s\n", device_path);
++    return 0;
++}
+ 
+-    int ret = av_hwdevice_ctx_create(&p->hwctx.av_device_ref,
+-                                     AV_HWDEVICE_TYPE_DRM,
+-                                     device_path, NULL, 0);
+-    talloc_free(tmp);
+-    if (ret != 0) {
+-        MP_VERBOSE(hw, "Failed to create hwdevice_ctx: %s\n", av_err2str(ret));
+-        return -1;
+-    }
++static int post_init(struct ra_hwdec *hw)
++{
++    struct priv_owner *p = hw->priv;
+ 
+     /*
+      * At the moment, there is no way to discover compatible formats
+@@ -154,6 +130,75 @@ static int init(struct ra_hwdec *hw)
+     return 0;
+ }
+ 
++static int init_drmprime(struct ra_hwdec *hw)
++{
++    struct priv_owner *p = hw->priv;
++
++    int ret = pre_init(hw);
++    if (ret < 0)
++        return ret;
++
++    /*
++     * The drm_params resource is not provided when using X11 or Wayland, but
++     * there are extensions that supposedly provide this information from the
++     * drivers. Not properly documented. Of course.
++     */
++    mpv_opengl_drm_params_v2 *params = ra_get_native_resource(hw->ra_ctx->ra,
++                                                              "drm_params_v2");
++
++    /*
++     * Respect drm_device option, so there is a way to control this when not
++     * using a DRM gpu context. If drm_params_v2 are present, they will already
++     * respect this option.
++     */
++    void *tmp = talloc_new(NULL);
++    struct drm_opts *drm_opts = mp_get_config_group(tmp, hw->global, &drm_conf);
++    const char *opt_path = drm_opts->device_path;
++
++    const char *device_path = params && params->render_fd > -1 ?
++                              drmGetRenderDeviceNameFromFd(params->render_fd) :
++                              opt_path ? opt_path : "/dev/dri/renderD128";
++    MP_VERBOSE(hw, "Using DRM device: %s\n", device_path);
++
++    ret = av_hwdevice_ctx_create(&p->hwctx.av_device_ref,
++                                 AV_HWDEVICE_TYPE_DRM,
++                                 device_path, NULL, 0);
++    talloc_free(tmp);
++    if (ret < 0) {
++        MP_VERBOSE(hw, "Failed to create hwdevice_ctx: %s\n", av_err2str(ret));
++        return ret;
++    }
++
++    return post_init(hw);
++}
++
++#if HAVE_V4L2REQUEST
++static int init_v4l2request(struct ra_hwdec *hw)
++{
++    struct priv_owner *p = hw->priv;
++
++    int ret = pre_init(hw);
++    if (ret < 0)
++        return ret;
++
++    /*
++     * AVCodecHWConfig contains a combo of a pixel format and hwdevice type,
++     * correct type must be created here or hwaccel will fail.
++     *
++     * FIXME: Create hwdevice based on type in AVCodecHWConfig
++     */
++    ret = av_hwdevice_ctx_create(&p->hwctx.av_device_ref,
++                                 AV_HWDEVICE_TYPE_V4L2REQUEST,
++                                 NULL, NULL, 0);
++    if (ret < 0) {
++        MP_VERBOSE(hw, "Failed to create hwdevice_ctx: %s\n", av_err2str(ret));
++        return ret;
++    }
++
++    return post_init(hw);
++}
++#endif
++
+ static void mapper_unmap(struct ra_hwdec_mapper *mapper)
+ {
+     struct priv_owner *p_owner = mapper->owner->priv;
+@@ -308,7 +353,7 @@ const struct ra_hwdec_driver ra_hwdec_drmprime = {
+     .priv_size = sizeof(struct priv_owner),
+     .imgfmts = {IMGFMT_DRMPRIME, 0},
+     .device_type = AV_HWDEVICE_TYPE_DRM,
+-    .init = init,
++    .init = init_drmprime,
+     .uninit = uninit,
+     .mapper = &(const struct ra_hwdec_mapper_driver){
+         .priv_size = sizeof(struct dmabuf_interop_priv),
+@@ -318,3 +363,21 @@ const struct ra_hwdec_driver ra_hwdec_drmprime = {
+         .unmap = mapper_unmap,
+     },
+ };
++
++#if HAVE_V4L2REQUEST
++const struct ra_hwdec_driver ra_hwdec_v4l2request = {
++    .name = "v4l2request",
++    .priv_size = sizeof(struct priv_owner),
++    .imgfmts = {IMGFMT_DRMPRIME, 0},
++    .device_type = AV_HWDEVICE_TYPE_V4L2REQUEST,
++    .init = init_v4l2request,
++    .uninit = uninit,
++    .mapper = &(const struct ra_hwdec_mapper_driver){
++        .priv_size = sizeof(struct dmabuf_interop_priv),
++        .init = mapper_init,
++        .uninit = mapper_uninit,
++        .map = mapper_map,
++        .unmap = mapper_unmap,
++    },
++};
++#endif
+diff --git a/video/out/hwdec/hwdec_drmprime_overlay.c b/video/out/hwdec/hwdec_drmprime_overlay.c
+index 61514f8e89..689e9b04e5 100644
+--- a/video/out/hwdec/hwdec_drmprime_overlay.c
++++ b/video/out/hwdec/hwdec_drmprime_overlay.c
+@@ -246,7 +246,7 @@ static void uninit(struct ra_hwdec *hw)
+     }
+ }
+ 
+-static int init(struct ra_hwdec *hw)
++static int pre_init(struct ra_hwdec *hw)
+ {
+     struct priv *p = hw->priv;
+     int draw_plane, drmprime_video_plane;
+@@ -267,15 +267,15 @@ static int init(struct ra_hwdec *hw)
+                                            drm_params->connector_id, draw_plane, drmprime_video_plane);
+         if (!p->ctx) {
+             mp_err(p->log, "Failed to retrieve DRM atomic context.\n");
+-            goto err;
++            return -1;
+         }
+         if (!p->ctx->drmprime_video_plane) {
+             mp_warn(p->log, "No drmprime video plane. You might need to specify it manually using --drm-drmprime-video-plane\n");
+-            goto err;
++            return -1;
+         }
+     } else {
+         mp_verbose(p->log, "Failed to retrieve DRM fd from native display.\n");
+-        goto err;
++        return -1;
+     }
+ 
+     drmModeCrtcPtr crtc;
+@@ -289,7 +289,7 @@ static int init(struct ra_hwdec *hw)
+     uint64_t has_prime;
+     if (drmGetCap(p->ctx->fd, DRM_CAP_PRIME, &has_prime) < 0) {
+         MP_ERR(hw, "Card does not support prime handles.\n");
+-        goto err;
++        return -1;
+     }
+ 
+     if (has_prime) {
+@@ -298,19 +298,67 @@ static int init(struct ra_hwdec *hw)
+ 
+     disable_video_plane(hw);
+ 
++    return 0;
++}
++
++static int init_drmprime(struct ra_hwdec *hw)
++{
++    struct priv *p = hw->priv;
++
++    int ret = pre_init(hw);
++    if (ret < 0)
++        goto err;
++
+     p->hwctx = (struct mp_hwdec_ctx) {
+         .driver_name = hw->driver->name,
+         .hw_imgfmt = IMGFMT_DRMPRIME,
+     };
+ 
+     char *device = drmGetDeviceNameFromFd2(p->ctx->fd);
+-    int ret = av_hwdevice_ctx_create(&p->hwctx.av_device_ref,
+-                                     AV_HWDEVICE_TYPE_DRM, device, NULL, 0);
++    ret = av_hwdevice_ctx_create(&p->hwctx.av_device_ref,
++                                 AV_HWDEVICE_TYPE_DRM, device, NULL, 0);
+ 
+     if (device)
+         free(device);
+ 
+-    if (ret != 0) {
++    if (ret < 0) {
++        MP_VERBOSE(hw, "Failed to create hwdevice_ctx: %s\n", av_err2str(ret));
++        goto err;
++    }
++
++    hwdec_devices_add(hw->devs, &p->hwctx);
++
++    return 0;
++
++err:
++    uninit(hw);
++    return ret;
++}
++
++#if HAVE_V4L2REQUEST
++static int init_v4l2request(struct ra_hwdec *hw)
++{
++    struct priv *p = hw->priv;
++
++    int ret = pre_init(hw);
++    if (ret < 0)
++        goto err;
++
++    p->hwctx = (struct mp_hwdec_ctx) {
++        .driver_name = hw->driver->name,
++        .hw_imgfmt = IMGFMT_DRMPRIME,
++    };
++
++    /*
++     * AVCodecHWConfig contains a combo of a pixel format and hwdevice type,
++     * correct type must be created here or hwaccel will fail.
++     *
++     * FIXME: Create hwdevice based on type in AVCodecHWConfig
++     */
++    ret = av_hwdevice_ctx_create(&p->hwctx.av_device_ref,
++                                 AV_HWDEVICE_TYPE_V4L2REQUEST,
++                                 NULL, NULL, 0);
++    if (ret < 0) {
+         MP_VERBOSE(hw, "Failed to create hwdevice_ctx: %s\n", av_err2str(ret));
+         goto err;
+     }
+@@ -321,15 +369,28 @@ static int init(struct ra_hwdec *hw)
+ 
+ err:
+     uninit(hw);
+-    return -1;
++    return ret;
+ }
++#endif
+ 
+ const struct ra_hwdec_driver ra_hwdec_drmprime_overlay = {
+     .name = "drmprime-overlay",
+     .priv_size = sizeof(struct priv),
+     .imgfmts = {IMGFMT_DRMPRIME, 0},
+     .device_type = AV_HWDEVICE_TYPE_DRM,
+-    .init = init,
++    .init = init_drmprime,
++    .overlay_frame = overlay_frame,
++    .uninit = uninit,
++};
++
++#if HAVE_V4L2REQUEST
++const struct ra_hwdec_driver ra_hwdec_v4l2request_overlay = {
++    .name = "v4l2request-overlay",
++    .priv_size = sizeof(struct priv),
++    .imgfmts = {IMGFMT_DRMPRIME, 0},
++    .device_type = AV_HWDEVICE_TYPE_V4L2REQUEST,
++    .init = init_v4l2request,
+     .overlay_frame = overlay_frame,
+     .uninit = uninit,
+ };
++#endif
+diff --git a/video/out/vo_dmabuf_wayland.c b/video/out/vo_dmabuf_wayland.c
+index 9b06643544..6d62849568 100644
+--- a/video/out/vo_dmabuf_wayland.c
++++ b/video/out/vo_dmabuf_wayland.c
+@@ -860,6 +860,7 @@ static int preinit(struct vo *vo)
+     // Initialize all possible hwdec drivers.
+     ra_hwdec_ctx_init(&p->hwdec_ctx, vo->hwdec_devs, "vaapi", false);
+     ra_hwdec_ctx_init(&p->hwdec_ctx, vo->hwdec_devs, "drmprime", false);
++    ra_hwdec_ctx_init(&p->hwdec_ctx, vo->hwdec_devs, "v4l2request", false);
+ 
+     p->src = (struct mp_rect){0, 0, 0, 0};
+     return 0;
+diff --git a/video/v4l2request.c b/video/v4l2request.c
+new file mode 100644
+index 0000000000..2aa4d14fea
+--- /dev/null
++++ b/video/v4l2request.c
+@@ -0,0 +1,34 @@
++/*
++ * This file is part of mpv.
++ *
++ * mpv is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU Lesser General Public
++ * License as published by the Free Software Foundation; either
++ * version 2.1 of the License, or (at your option) any later version.
++ *
++ * mpv is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU Lesser General Public License for more details.
++ *
++ * You should have received a copy of the GNU Lesser General Public
++ * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
++ */
++
++#include <libavutil/hwcontext.h>
++
++#include "hwdec.h"
++
++static struct AVBufferRef *v4l2request_create_standalone(struct mpv_global *global,
++        struct mp_log *log, struct hwcontext_create_dev_params *params)
++{
++    AVBufferRef* ref = NULL;
++    av_hwdevice_ctx_create(&ref, AV_HWDEVICE_TYPE_V4L2REQUEST, NULL, NULL, 0);
++
++    return ref;
++}
++
++const struct hwcontext_fns hwcontext_fns_v4l2request = {
++    .av_hwdevice_type = AV_HWDEVICE_TYPE_V4L2REQUEST,
++    .create_dev = v4l2request_create_standalone,
++};
+-- 
+2.52.0
+

arch/mpv-fourier/PKGBUILD

@@ -23,8 +23,8 @@ pkgname=mpv-fourier
 _upstreampkg=mpv
 epoch=1
 pkgver=0.41.0
-pkgrel=9
+pkgrel=10
-pkgdesc='mpv with fourier-umbrella patches (vo_dmabuf_wayland explicit cache-sync workaround)'
+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