[FFmpeg-devel] [PATCH] Fix failure to initialize ddagrab if adapter ID is specified

[James Almer]

On 8/8/2023 2:52 PM, Jøger Hansegård wrote:
> Fix failure to initialize ddagrab if adapter ID is specified.
> 
> If an adapter ID is specified when initializing hw device for d3d11va,
> ddagrab does not work on Windows 11. This prevents capturing screens
> connected to a secondary adapter.
> 
> Failing command:
>      ffmpeg -init_hw_device d3d11va:0 -filter_complex ddagrab=0,hwdownload,format=bgra -c:v h264_mf output.mkv
> 
> The reason is that d3d11va_device_create uses CreateDXGIFactory to
> create a DXGIFactory 1.0. This causes init_dxgi_dda's call to
> IDXGIOutput5_DuplicateOutput1 to fail because it is only supported on
> DXGI 1.1 and higher.
> 
> The fix is to always crate DXGI factory using CreateDXGIFactory1 as
> proposed in this patch.
> 
> Fixes: #10385
> ---
>   libavutil/hwcontext_d3d11va.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavutil/hwcontext_d3d11va.c b/libavutil/hwcontext_d3d11va.c
> index aa50538d64..fa8d5410f2 100644
> --- a/libavutil/hwcontext_d3d11va.c
> +++ b/libavutil/hwcontext_d3d11va.c
> @@ -62,7 +62,7 @@ static av_cold void load_functions(void)
>           return;
> 
>       mD3D11CreateDevice = (PFN_D3D11_CREATE_DEVICE) GetProcAddress(d3dlib, "D3D11CreateDevice");
> -    mCreateDXGIFactory = (PFN_CREATE_DXGI_FACTORY) GetProcAddress(dxgilib, "CreateDXGIFactory");
> +    mCreateDXGIFactory = (PFN_CREATE_DXGI_FACTORY) GetProcAddress(dxgilib, "CreateDXGIFactory1");
>   #else
>       // In UWP (which lacks LoadLibrary), CreateDXGIFactory isn't available,
>       // only CreateDXGIFactory1
> --
> 2.40.1.windows.1

LGTM, but i wonder why are we using IDXGIFactory2 and its functions in 
hwcontext_d3d11va if we use DXGI 1.1?

Maybe we could do the following:

> diff --git a/libavutil/hwcontext_d3d11va.c b/libavutil/hwcontext_d3d11va.c
> index aa50538d64..fb6f240c56 100644
> --- a/libavutil/hwcontext_d3d11va.c
> +++ b/libavutil/hwcontext_d3d11va.c
> @@ -24,7 +24,7 @@
> 
>  #include <initguid.h>
>  #include <d3d11.h>
> -#include <dxgi1_2.h>
> +#include <dxgi.h>
> 
>  #if HAVE_DXGIDEBUG_H
>  #include <dxgidebug.h>
> @@ -62,7 +62,7 @@ static av_cold void load_functions(void)
>          return;
> 
>      mD3D11CreateDevice = (PFN_D3D11_CREATE_DEVICE) GetProcAddress(d3dlib, "D3D11CreateDevice");
> -    mCreateDXGIFactory = (PFN_CREATE_DXGI_FACTORY) GetProcAddress(dxgilib, "CreateDXGIFactory");
> +    mCreateDXGIFactory = (PFN_CREATE_DXGI_FACTORY) GetProcAddress(dxgilib, "CreateDXGIFactory1");
>  #else
>      // In UWP (which lacks LoadLibrary), CreateDXGIFactory isn't available,
>      // only CreateDXGIFactory1
> @@ -581,19 +581,19 @@ static int d3d11va_device_create(AVHWDeviceContext *ctx, const char *device,
>      }
> 
>      if (device) {
> -        IDXGIFactory2 *pDXGIFactory;
> -        hr = mCreateDXGIFactory(&IID_IDXGIFactory2, (void **)&pDXGIFactory);
> +        IDXGIFactory1 *pDXGIFactory;
> +        hr = mCreateDXGIFactory(&IID_IDXGIFactory1, (void **)&pDXGIFactory);
>          if (SUCCEEDED(hr)) {
>              int adapter = atoi(device);
> -            if (FAILED(IDXGIFactory2_EnumAdapters(pDXGIFactory, adapter, &pAdapter)))
> +            if (FAILED(IDXGIFactory1_EnumAdapters(pDXGIFactory, adapter, &pAdapter)))
>                  pAdapter = NULL;
> -            IDXGIFactory2_Release(pDXGIFactory);
> +            IDXGIFactory1_Release(pDXGIFactory);
>          }
>      }
> 
>      if (pAdapter) {
>          DXGI_ADAPTER_DESC desc;
> -        hr = IDXGIAdapter2_GetDesc(pAdapter, &desc);
> +        hr = IDXGIAdapter1_GetDesc(pAdapter, &desc);
>          if (!FAILED(hr)) {
>              av_log(ctx, AV_LOG_INFO, "Using device %04x:%04x (%ls).\n",
>                     desc.VendorId, desc.DeviceId, desc.Description);

Not sure what Martin thinks.