vo: vulkan: request additional extensions and features for ffmpeg

Vulkan hwdec interop with the ffmpeg 6.1 vulkan code will require
additional features beyond those activated by libplacebo by default.

Enabling these features requires both requesting the features'
extensions and then explicitly turning on the features. libplacebo
handles detecting unsupported features and dropping them, to avoid
failing to create the vulkan device.

We then leave it to ffmpeg to decide if any missing features are
required for functionality, and error out if necessary.

As ffmpeg requires at least one bleeding edge extension (descriptor
buffers), all of this logic is gated on the presence of sufficiently
new Vulkan headers.

video/out/vulkan/context.c

@@ -161,6 +161,47 @@ bool ra_vk_ctx_init(struct ra_ctx *ctx, struct mpvk_ctx *vk,
     p->params = params;
     p->opts = mp_get_config_group(p, ctx->global, &vulkan_conf);
 
+#if HAVE_VULKAN_INTEROP && defined(VK_EXT_descriptor_buffer)
+    /*
+     * Request the additional extensions and features required to make full use
+     * of the ffmpeg Vulkan hwcontext and video decoding capability.
+     */
+    const char *opt_extensions[] = {
+        VK_EXT_DESCRIPTOR_BUFFER_EXTENSION_NAME,
+        VK_EXT_SHADER_ATOMIC_FLOAT_EXTENSION_NAME,
+        VK_KHR_VIDEO_DECODE_QUEUE_EXTENSION_NAME,
+        VK_KHR_VIDEO_DECODE_H264_EXTENSION_NAME,
+        VK_KHR_VIDEO_DECODE_H265_EXTENSION_NAME,
+        VK_KHR_VIDEO_QUEUE_EXTENSION_NAME,
+    };
+
+    VkPhysicalDeviceDescriptorBufferFeaturesEXT descriptor_buffer_feature = {
+        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DESCRIPTOR_BUFFER_FEATURES_EXT,
+        .pNext = NULL,
+        .descriptorBuffer = true,
+        .descriptorBufferPushDescriptors = true,
+    };
+
+    VkPhysicalDeviceShaderAtomicFloatFeaturesEXT atomic_float_feature = {
+        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_ATOMIC_FLOAT_FEATURES_EXT,
+        .pNext = &descriptor_buffer_feature,
+        .shaderBufferFloat32Atomics = true,
+        .shaderBufferFloat32AtomicAdd = true,
+    };
+
+    VkPhysicalDeviceFeatures2 features = {
+        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2,
+        .pNext = &atomic_float_feature,
+    };
+
+#else
+    const char *opt_extensions[] = {
+    };
+    VkPhysicalDeviceFeatures2 features = {
+        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2,
+    };
+#endif // HAVE_VULKAN_INTEROP && defined(VK_EXT_descriptor_buffer)
+
     assert(vk->pllog);
     assert(vk->vkinst);
     vk->vulkan = pl_vulkan_create(vk->pllog, &(struct pl_vulkan_params) {
@@ -171,6 +212,12 @@ bool ra_vk_ctx_init(struct ra_ctx *ctx, struct mpvk_ctx *vk,
         .async_compute = p->opts->async_compute,
         .queue_count = p->opts->queue_count,
         .device_name = p->opts->device,
+#if HAVE_VULKAN_INTEROP && defined(VK_EXT_descriptor_buffer)
+        .extra_queues = VK_QUEUE_VIDEO_DECODE_BIT_KHR,
+#endif
+        .features = &features,
+        .opt_extensions = opt_extensions,
+        .num_opt_extensions = MP_ARRAY_SIZE(opt_extensions),
     });
     if (!vk->vulkan)
         goto error;