[FFmpeg-devel] [PATCH] hwcontext_vulkan: use VkPhysicalDeviceTimelineSemaphoreFeatures to check for timeline semaphore supporting

[Lynne]

27 Jan 2022, 04:39 by quinkblack at foxmail.com:

> VkPhysicalDeviceVulkan12Features isn't implemented on MoltenVK yet.
> VkPhysicalDeviceTimelineSemaphoreFeatures is less versatile but
> simple. None of device_features_1_1 nor device_features_1_2 has real
> usage yet, keep the code for future.
> ---
>  libavutil/hwcontext_vulkan.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/libavutil/hwcontext_vulkan.c b/libavutil/hwcontext_vulkan.c
> index ae19fc2ab6..2e219511c9 100644
> --- a/libavutil/hwcontext_vulkan.c
> +++ b/libavutil/hwcontext_vulkan.c
> @@ -1321,8 +1321,16 @@ static int vulkan_device_create_internal(AVHWDeviceContext *ctx,
>  VulkanDevicePriv *p = ctx->internal->priv;
>  FFVulkanFunctions *vk = &p->vkfn;
>  AVVulkanDeviceContext *hwctx = ctx->hwctx;
> +    /* VkPhysicalDeviceVulkan12Features has a timelineSemaphore field, but
> +     * MoltenVK doesn't implement VkPhysicalDeviceVulkan12Features yet, so we
> +     * use VkPhysicalDeviceTimelineSemaphoreFeatures directly.
> +     */
> +    VkPhysicalDeviceTimelineSemaphoreFeatures timeline_features = {
> +        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_TIMELINE_SEMAPHORE_FEATURES,
> +    };
>  VkPhysicalDeviceVulkan12Features dev_features_1_2 = {
>  .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_2_FEATURES,
> +        .pNext = &timeline_features,
>  };
>  VkPhysicalDeviceVulkan11Features dev_features_1_1 = {
>  .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_1_FEATURES,
> @@ -1366,7 +1374,7 @@ static int vulkan_device_create_internal(AVHWDeviceContext *ctx,
>  #undef COPY_FEATURE
>  
>  /* We require timeline semaphores */
> -    if (!dev_features_1_2.timelineSemaphore) {
> +    if (!timeline_features.timelineSemaphore) {
>  av_log(ctx, AV_LOG_ERROR, "Device does not support timeline semaphores!\n");
>  err = AVERROR(ENOSYS);
>  goto end;
>

I didn't have a strong opinion on this, and on my nvidia testing machine,
VkPhysicalDeviceVulkan12Features.timelineSemaphore isn't set for
some reason (despite alleged 1.2 compliance), so this may help there.
Pushed, thanks.