[FFmpeg-devel,v2,8/8] avfilter: add vsrc_ddagrab

---
 Changelog                          |   1 +
 configure                          |   7 +
 doc/filters.texi                   |  68 ++
 libavfilter/Makefile               |   1 +
 libavfilter/allfilters.c           |   1 +
 libavfilter/version.h              |   2 +-
 libavfilter/vsrc_ddagrab.c         | 980 +++++++++++++++++++++++++++++
 libavfilter/vsrc_ddagrab_shaders.h | 120 ++++
 8 files changed, 1179 insertions(+), 1 deletion(-)
 create mode 100644 libavfilter/vsrc_ddagrab.c
 create mode 100644 libavfilter/vsrc_ddagrab_shaders.h

On 2022-07-09 04:24 am, Timo Rothenpieler wrote:
> ---
>   Changelog                          |   1 +
>   configure                          |   7 +
>   doc/filters.texi                   |  68 ++
>   libavfilter/Makefile               |   1 +
>   libavfilter/allfilters.c           |   1 +
>   libavfilter/version.h              |   2 +-
>   libavfilter/vsrc_ddagrab.c         | 980 +++++++++++++++++++++++++++++
>   libavfilter/vsrc_ddagrab_shaders.h | 120 ++++
>   8 files changed, 1179 insertions(+), 1 deletion(-)
>   create mode 100644 libavfilter/vsrc_ddagrab.c
>   create mode 100644 libavfilter/vsrc_ddagrab_shaders.h
>
> diff --git a/Changelog b/Changelog
> index 1a7c84b7f8..9467e92dd1 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -24,6 +24,7 @@ version 5.1:
>   - VDPAU AV1 hwaccel
>   - PHM image format support
>   - remap_opencl filter
> +- ddagrab (Desktop Duplication) video source filter

The source filters are all generative filters. This should be called a 
capture filter.
Why is it a filter instead of in lavd?

Regards,
Gyan



>   
>   
>   version 5.0:
> diff --git a/configure b/configure
> index 7d5c4900bf..5a1794ebdc 100755
> --- a/configure
> +++ b/configure
> @@ -2309,6 +2309,7 @@ SYSTEM_FUNCS="
>       SetDllDirectory
>       setmode
>       setrlimit
> +    SetThreadDpiAwarenessContext
>       Sleep
>       strerror_r
>       sysconf
> @@ -2352,6 +2353,7 @@ TOOLCHAIN_FEATURES="
>   "
>   
>   TYPES_LIST="
> +    IDXGIOutput5
>       kCMVideoCodecType_HEVC
>       kCMVideoCodecType_HEVCWithAlpha
>       kCMVideoCodecType_VP9
> @@ -3154,6 +3156,8 @@ overlay_cuda_filter_deps="ffnvcodec"
>   overlay_cuda_filter_deps_any="cuda_nvcc cuda_llvm"
>   sharpen_npp_filter_deps="ffnvcodec libnpp"
>   
> +ddagrab_filter_deps="d3d11va IDXGIOutput1"
> +
>   amf_deps_any="libdl LoadLibrary"
>   nvenc_deps="ffnvcodec"
>   nvenc_deps_any="libdl LoadLibrary"
> @@ -6389,10 +6393,13 @@ check_struct "sys/time.h sys/resource.h" "struct rusage" ru_maxrss
>   check_type "windows.h dxva.h" "DXVA_PicParams_AV1" -DWINAPI_FAMILY=WINAPI_FAMILY_DESKTOP_APP -D_CRT_BUILD_DESKTOP_APP=0
>   check_type "windows.h dxva.h" "DXVA_PicParams_HEVC" -DWINAPI_FAMILY=WINAPI_FAMILY_DESKTOP_APP -D_CRT_BUILD_DESKTOP_APP=0
>   check_type "windows.h dxva.h" "DXVA_PicParams_VP9" -DWINAPI_FAMILY=WINAPI_FAMILY_DESKTOP_APP -D_CRT_BUILD_DESKTOP_APP=0
> +check_type "windows.h dxgi1_2.h" "IDXGIOutput1"
> +check_type "windows.h dxgi1_5.h" "IDXGIOutput5"
>   check_type "windows.h d3d11.h" "ID3D11VideoDecoder"
>   check_type "windows.h d3d11.h" "ID3D11VideoContext"
>   check_type "d3d9.h dxva2api.h" DXVA2_ConfigPictureDecode -D_WIN32_WINNT=0x0602
>   check_func_headers mfapi.h MFCreateAlignedMemoryBuffer -lmfplat
> +check_func_headers windows.h SetThreadDpiAwarenessContext -D_WIN32_WINNT=0x0A00
>   
>   check_type "vdpau/vdpau.h" "VdpPictureInfoHEVC"
>   check_type "vdpau/vdpau.h" "VdpPictureInfoVP9"
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 296b0693ae..bb651112f6 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -26390,6 +26390,74 @@ need for a nullsrc video source.
>   @end itemize
>   
>   
> +@section ddagrab
> +
> +Captures the Windows Desktop via Desktop Duplication API.
> +
> +The filter exclusively returns D3D11 Hardware Frames, for on-gpu encoding
> +or processing. So an explicit @ref{hwdownload} is needed for any kind of
> +software processing.
> +
> +It accepts the following options:
> +
> +@table @option
> +@item output_idx
> +DXGI Output Index to capture.
> +
> +Usually corresponds to the index Windows has given the screen minus one,
> +so it's starting at 0.
> +
> +Defaults to output 0.
> +
> +@item draw_mouse
> +Whether to draw the mouse cursor.
> +
> +Defaults to true.
> +
> +Only affects hardware cursors. If a game or application renders its own cursor,
> +it'll always be captured.
> +
> +@item framerate
> +Framerate at which the desktop will be captured.
> +
> +Defaults to 30 FPS.
> +
> +@item video_size
> +Specify the size of the captured video.
> +
> +Defaults to the full size of the screen.
> +
> +Cropped from the bottom/right if smaller than screen size.
> +
> +@item offset_x
> +Horizontal offset of the captured video.
> +
> +@item offset_y
> +Vertical offset of the captured video.
> +
> +@end table
> +
> +@subsection Examples
> +
> +Capture primary screen and encode using nvenc:
> +@example
> +ffmpeg -f lavfi -i ddagrab -c:v h264_nvenc -cq 18 output.mp4
> +@end example
> +
> +You can also skip the lavfi device and directly use the filter.
> +Also demonstrates downloading the frame and encoding with libx264.
> +Explicit output format specification is required in this case:
> +@example
> +ffmpeg -filter_complex ddagrab=output_idx=1:framerate=60,hwdownload,format=bgra -c:v libx264 -crf 18 output.mp4
> +@end example
> +
> +If you want to capture only a subsection of the desktop, this can be achieved
> +by specifying a smaller size and its offsets into the screen:
> +@example
> +ddagrab=video_size=800x600:offset_x=100:offset_y=100
> +@end example
> +
> +
>   @section gradients
>   Generate several gradients.
>   
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 139f7cb751..e161196d87 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -555,6 +555,7 @@ OBJS-$(CONFIG_COLOR_FILTER)                  += vsrc_testsrc.o
>   OBJS-$(CONFIG_COLORCHART_FILTER)             += vsrc_testsrc.o
>   OBJS-$(CONFIG_COLORSPECTRUM_FILTER)          += vsrc_testsrc.o
>   OBJS-$(CONFIG_COREIMAGESRC_FILTER)           += vf_coreimage.o
> +OBJS-$(CONFIG_DDAGRAB_FILTER)                += vsrc_ddagrab.o
>   OBJS-$(CONFIG_FREI0R_SRC_FILTER)             += vf_frei0r.o
>   OBJS-$(CONFIG_GRADIENTS_FILTER)              += vsrc_gradients.o
>   OBJS-$(CONFIG_HALDCLUTSRC_FILTER)            += vsrc_testsrc.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 3018850b4b..bd3d2c2d47 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -523,6 +523,7 @@ extern const AVFilter ff_vsrc_color;
>   extern const AVFilter ff_vsrc_colorchart;
>   extern const AVFilter ff_vsrc_colorspectrum;
>   extern const AVFilter ff_vsrc_coreimagesrc;
> +extern const AVFilter ff_vsrc_ddagrab;
>   extern const AVFilter ff_vsrc_frei0r_src;
>   extern const AVFilter ff_vsrc_gradients;
>   extern const AVFilter ff_vsrc_haldclutsrc;
> diff --git a/libavfilter/version.h b/libavfilter/version.h
> index 37f03b44a6..2f4f4c6c21 100644
> --- a/libavfilter/version.h
> +++ b/libavfilter/version.h
> @@ -31,7 +31,7 @@
>   
>   #include "version_major.h"
>   
> -#define LIBAVFILTER_VERSION_MINOR  42
> +#define LIBAVFILTER_VERSION_MINOR  43
>   #define LIBAVFILTER_VERSION_MICRO 100
>   
>   
> diff --git a/libavfilter/vsrc_ddagrab.c b/libavfilter/vsrc_ddagrab.c
> new file mode 100644
> index 0000000000..fdcb7515ec
> --- /dev/null
> +++ b/libavfilter/vsrc_ddagrab.c
> @@ -0,0 +1,980 @@
> +/*
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg 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.
> + *
> + * FFmpeg 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 FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include "config.h"
> +
> +#if !defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0A00
> +#undef _WIN32_WINNT
> +#define _WIN32_WINNT 0x0A00
> +#endif
> +#define WIN32_LEAN_AND_MEAN
> +
> +#include <windows.h>
> +
> +#define COBJMACROS
> +
> +#include <initguid.h>
> +#include <d3d11.h>
> +#include <dxgi1_2.h>
> +#if HAVE_IDXGIOUTPUT5
> +#include <dxgi1_5.h>
> +#endif
> +
> +#include "libavutil/opt.h"
> +#include "libavutil/time.h"
> +#include "libavutil/avstring.h"
> +#include "libavutil/avassert.h"
> +#include "libavutil/hwcontext.h"
> +#include "libavutil/hwcontext_d3d11va.h"
> +#include "avfilter.h"
> +#include "internal.h"
> +#include "formats.h"
> +#include "video.h"
> +
> +#include "vsrc_ddagrab_shaders.h"
> +
> +// avutil/time.h takes and returns time in microseconds
> +#define TIMER_RES 1000000
> +#define TIMER_RES64 INT64_C(1000000)
> +
> +typedef struct DdagrabContext {
> +    const AVClass *class;
> +
> +    AVBufferRef *device_ref;
> +    AVHWDeviceContext *device_ctx;
> +    AVD3D11VADeviceContext *device_hwctx;
> +
> +    AVBufferRef *frames_ref;
> +    AVHWFramesContext *frames_ctx;
> +    AVD3D11VAFramesContext *frames_hwctx;
> +
> +    DXGI_OUTPUT_DESC output_desc;
> +    IDXGIOutputDuplication *dxgi_outdupl;
> +    AVFrame *last_frame;
> +
> +    int mouse_x, mouse_y;
> +    ID3D11Texture2D *mouse_texture;
> +    ID3D11ShaderResourceView* mouse_resource_view ;
> +
> +    AVRational time_base;
> +    int64_t time_frame;
> +    int64_t time_timeout;
> +    int64_t first_pts;
> +
> +    DXGI_FORMAT raw_format;
> +    int raw_width;
> +    int raw_height;
> +
> +    ID3D11Texture2D *probed_texture;
> +
> +    ID3D11VertexShader *vertex_shader;
> +    ID3D11InputLayout *input_layout;
> +    ID3D11PixelShader *pixel_shader;
> +    ID3D11Buffer *const_buffer;
> +    ID3D11SamplerState *sampler_state;
> +    ID3D11BlendState *blend_state;
> +
> +    int        output_idx;
> +    int        draw_mouse;
> +    AVRational framerate;
> +    int        width;
> +    int        height;
> +    int        offset_x;
> +    int        offset_y;
> +} DdagrabContext;
> +
> +#define OFFSET(x) offsetof(DdagrabContext, x)
> +#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
> +static const AVOption ddagrab_options[] = {
> +    { "output_idx", "dda output index to capture", OFFSET(output_idx), AV_OPT_TYPE_INT,        { .i64 = 0    },       0, INT_MAX, FLAGS },
> +    { "draw_mouse", "draw the mouse pointer",      OFFSET(draw_mouse), AV_OPT_TYPE_BOOL,       { .i64 = 1    },       0,       1, FLAGS },
> +    { "framerate",  "set video frame rate",        OFFSET(framerate),  AV_OPT_TYPE_VIDEO_RATE, { .str = "30" },       0, INT_MAX, FLAGS },
> +    { "video_size", "set video frame size",        OFFSET(width),      AV_OPT_TYPE_IMAGE_SIZE, { .str = NULL },       0,       0, FLAGS },
> +    { "offset_x",   "capture area x offset",       OFFSET(offset_x),   AV_OPT_TYPE_INT,        { .i64 = 0    }, INT_MIN, INT_MAX, FLAGS },
> +    { "offset_y",   "capture area y offset",       OFFSET(offset_y),   AV_OPT_TYPE_INT,        { .i64 = 0    }, INT_MIN, INT_MAX, FLAGS },
> +    { NULL }
> +};
> +
> +AVFILTER_DEFINE_CLASS(ddagrab);
> +
> +static inline void release_resource(void *resource)
> +{
> +    IUnknown **resp = (IUnknown**)resource;
> +    if (*resp) {
> +        IUnknown_Release(*resp);
> +        *resp = NULL;
> +    }
> +}
> +
> +static av_cold void ddagrab_uninit(AVFilterContext *avctx)
> +{
> +    DdagrabContext *dda = avctx->priv;
> +
> +    release_resource(&dda->blend_state);
> +    release_resource(&dda->sampler_state);
> +    release_resource(&dda->pixel_shader);
> +    release_resource(&dda->input_layout);
> +    release_resource(&dda->vertex_shader);
> +    release_resource(&dda->const_buffer);
> +
> +    release_resource(&dda->probed_texture);
> +
> +    release_resource(&dda->dxgi_outdupl);
> +    release_resource(&dda->mouse_resource_view);
> +    release_resource(&dda->mouse_texture);
> +
> +    av_frame_free(&dda->last_frame);
> +    av_buffer_unref(&dda->frames_ref);
> +    av_buffer_unref(&dda->device_ref);
> +}
> +
> +static av_cold int init_dxgi_dda(AVFilterContext *avctx)
> +{
> +    DdagrabContext *dda = avctx->priv;
> +    IDXGIDevice *dxgi_device = NULL;
> +    IDXGIAdapter *dxgi_adapter = NULL;
> +    IDXGIOutput *dxgi_output = NULL;
> +    IDXGIOutput1 *dxgi_output1 = NULL;
> +#if HAVE_IDXGIOUTPUT5 && HAVE_SETTHREADDPIAWARENESSCONTEXT
> +    IDXGIOutput5 *dxgi_output5 = NULL;
> +#endif
> +    HRESULT hr;
> +
> +    hr = ID3D11Device_QueryInterface(dda->device_hwctx->device, &IID_IDXGIDevice, (void**)&dxgi_device);
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "Failed querying IDXGIDevice\n");
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    hr = IDXGIDevice_GetParent(dxgi_device, &IID_IDXGIAdapter, (void**)&dxgi_adapter);
> +    IDXGIDevice_Release(dxgi_device);
> +    dxgi_device = NULL;
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "Failed getting parent IDXGIAdapter\n");
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    hr = IDXGIAdapter_EnumOutputs(dxgi_adapter, dda->output_idx, &dxgi_output);
> +    IDXGIAdapter_Release(dxgi_adapter);
> +    dxgi_adapter = NULL;
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "Failed to enumerate DXGI output %d\n", dda->output_idx);
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    hr = IDXGIOutput_GetDesc(dxgi_output, &dda->output_desc);
> +    if (FAILED(hr)) {
> +        IDXGIOutput_Release(dxgi_output);
> +        av_log(avctx, AV_LOG_ERROR, "Failed getting output description\n");
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +#if HAVE_IDXGIOUTPUT5 && HAVE_SETTHREADDPIAWARENESSCONTEXT
> +    hr = IDXGIOutput_QueryInterface(dxgi_output, &IID_IDXGIOutput5, (void**)&dxgi_output5);
> +    if (SUCCEEDED(hr)) {
> +        DPI_AWARENESS_CONTEXT prev_dpi_ctx;
> +        DXGI_FORMAT formats[] = {
> +			DXGI_FORMAT_R10G10B10A2_UNORM,
> +			DXGI_FORMAT_B8G8R8A8_UNORM
> +		};
> +
> +        IDXGIOutput_Release(dxgi_output);
> +        dxgi_output = NULL;
> +
> +        prev_dpi_ctx = SetThreadDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
> +        if (!prev_dpi_ctx)
> +            av_log(avctx, AV_LOG_WARNING, "Failed enabling DPI awareness for DDA\n");
> +
> +        hr = IDXGIOutput5_DuplicateOutput1(dxgi_output5,
> +            (IUnknown*)dda->device_hwctx->device,
> +            0,
> +            FF_ARRAY_ELEMS(formats),
> +            formats,
> +            &dda->dxgi_outdupl);
> +        IDXGIOutput5_Release(dxgi_output5);
> +        dxgi_output5 = NULL;
> +
> +        if (prev_dpi_ctx)
> +            SetThreadDpiAwarenessContext(prev_dpi_ctx);
> +    } else {
> +        av_log(avctx, AV_LOG_DEBUG, "Falling back to IDXGIOutput1\n");
> +#else
> +    {
> +#endif
> +        hr = IDXGIOutput_QueryInterface(dxgi_output, &IID_IDXGIOutput1, (void**)&dxgi_output1);
> +        IDXGIOutput_Release(dxgi_output);
> +        dxgi_output = NULL;
> +        if (FAILED(hr)) {
> +            av_log(avctx, AV_LOG_ERROR, "Failed querying IDXGIOutput1\n");
> +            return AVERROR_EXTERNAL;
> +        }
> +
> +        hr = IDXGIOutput1_DuplicateOutput(dxgi_output1,
> +            (IUnknown*)dda->device_hwctx->device,
> +            &dda->dxgi_outdupl);
> +        IDXGIOutput1_Release(dxgi_output1);
> +        dxgi_output1 = NULL;
> +    }
> +
> +    if (hr == DXGI_ERROR_NOT_CURRENTLY_AVAILABLE) {
> +        av_log(avctx, AV_LOG_ERROR, "Too many open duplication sessions\n");
> +        return AVERROR(EBUSY);
> +    } else if (hr == DXGI_ERROR_UNSUPPORTED) {
> +        av_log(avctx, AV_LOG_ERROR, "Selected output not supported\n");
> +        return AVERROR_EXTERNAL;
> +    } else if (hr == E_INVALIDARG) {
> +        av_log(avctx, AV_LOG_ERROR, "Invalid output duplication argument\n");
> +        return AVERROR(EINVAL);
> +    } else if (hr == E_ACCESSDENIED) {
> +        av_log(avctx, AV_LOG_ERROR, "Desktop duplication access denied\n");
> +        return AVERROR(EPERM);
> +    } else if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "Failed duplicating output\n");
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    dda->raw_width = dda->output_desc.DesktopCoordinates.right - dda->output_desc.DesktopCoordinates.left;
> +    dda->raw_height = dda->output_desc.DesktopCoordinates.bottom - dda->output_desc.DesktopCoordinates.top;
> +    av_log(avctx, AV_LOG_VERBOSE, "Opened dxgi output %d with dimensions %dx%d\n",
> +           dda->output_idx, dda->raw_width, dda->raw_height);
> +
> +    return 0;
> +}
> +
> +typedef struct ConstBufferData
> +{
> +    float width;
> +    float height;
> +
> +    uint64_t padding;
> +} ConstBufferData;
> +
> +static const D3D11_INPUT_ELEMENT_DESC vertex_shader_input_layout[] =
> +{
> +    { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0,  0, D3D11_INPUT_PER_VERTEX_DATA, 0 },
> +    { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,    0, 12, D3D11_INPUT_PER_VERTEX_DATA, 0 }
> +};
> +
> +static av_cold int init_render_resources(AVFilterContext *avctx)
> +{
> +    DdagrabContext *dda = avctx->priv;
> +    ID3D11Device *dev = dda->device_hwctx->device;
> +    D3D11_SAMPLER_DESC sampler_desc = { 0 };
> +    D3D11_BLEND_DESC blend_desc = { 0 };
> +    D3D11_BUFFER_DESC buffer_desc = { 0 };
> +    D3D11_SUBRESOURCE_DATA buffer_data = { 0 };
> +    ConstBufferData const_data = { 0 };
> +    HRESULT hr;
> +
> +    hr = ID3D11Device_CreateVertexShader(dev,
> +        vertex_shader_bytes,
> +        FF_ARRAY_ELEMS(vertex_shader_bytes),
> +        NULL,
> +        &dda->vertex_shader);
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "CreateVertexShader failed: %lx\n", hr);
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    hr = ID3D11Device_CreateInputLayout(dev,
> +        vertex_shader_input_layout,
> +        FF_ARRAY_ELEMS(vertex_shader_input_layout),
> +        vertex_shader_bytes,
> +        FF_ARRAY_ELEMS(vertex_shader_bytes),
> +        &dda->input_layout);
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "CreateInputLayout failed: %lx\n", hr);
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    hr = ID3D11Device_CreatePixelShader(dev,
> +        pixel_shader_bytes,
> +        FF_ARRAY_ELEMS(pixel_shader_bytes),
> +        NULL,
> +        &dda->pixel_shader);
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "CreatePixelShader failed: %lx\n", hr);
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    const_data = (ConstBufferData){ dda->width, dda->height };
> +
> +    buffer_data.pSysMem = &const_data;
> +    buffer_desc.ByteWidth = sizeof(const_data);
> +    buffer_desc.Usage = D3D11_USAGE_IMMUTABLE;
> +    buffer_desc.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
> +    hr = ID3D11Device_CreateBuffer(dev,
> +        &buffer_desc,
> +        &buffer_data,
> +        &dda->const_buffer);
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "CreateBuffer const buffer failed: %lx\n", hr);
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    sampler_desc.Filter = D3D11_FILTER_MIN_MAG_MIP_LINEAR;
> +    sampler_desc.AddressU = D3D11_TEXTURE_ADDRESS_CLAMP;
> +    sampler_desc.AddressV = D3D11_TEXTURE_ADDRESS_CLAMP;
> +    sampler_desc.AddressW = D3D11_TEXTURE_ADDRESS_CLAMP;
> +    sampler_desc.ComparisonFunc = D3D11_COMPARISON_NEVER;
> +    hr = ID3D11Device_CreateSamplerState(dev,
> +        &sampler_desc,
> +        &dda->sampler_state);
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "CreateSamplerState failed: %lx\n", hr);
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    blend_desc.AlphaToCoverageEnable = FALSE;
> +    blend_desc.IndependentBlendEnable = FALSE;
> +    blend_desc.RenderTarget[0].BlendEnable = TRUE;
> +    blend_desc.RenderTarget[0].SrcBlend = D3D11_BLEND_SRC_ALPHA;
> +    blend_desc.RenderTarget[0].DestBlend = D3D11_BLEND_INV_SRC_ALPHA;
> +    blend_desc.RenderTarget[0].BlendOp = D3D11_BLEND_OP_ADD;
> +    blend_desc.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_ONE;
> +    blend_desc.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_ZERO;
> +    blend_desc.RenderTarget[0].BlendOpAlpha = D3D11_BLEND_OP_ADD;
> +    blend_desc.RenderTarget[0].RenderTargetWriteMask = D3D11_COLOR_WRITE_ENABLE_ALL;
> +    hr = ID3D11Device_CreateBlendState(dev,
> +        &blend_desc,
> +        &dda->blend_state);
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "CreateBlendState failed: %lx\n", hr);
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    return 0;
> +}
> +
> +static av_cold int ddagrab_init(AVFilterContext *avctx)
> +{
> +    DdagrabContext *dda = avctx->priv;
> +    int ret = 0;
> +
> +    if (avctx->hw_device_ctx) {
> +        dda->device_ctx = (AVHWDeviceContext*)avctx->hw_device_ctx->data;
> +
> +        if (dda->device_ctx->type != AV_HWDEVICE_TYPE_D3D11VA) {
> +            av_log(avctx, AV_LOG_ERROR, "Non-D3D11VA input hw_device_ctx\n");
> +            return AVERROR(EINVAL);
> +        }
> +
> +        dda->device_ref = av_buffer_ref(avctx->hw_device_ctx);
> +        if (!dda->device_ref)
> +            return AVERROR(ENOMEM);
> +
> +        av_log(avctx, AV_LOG_VERBOSE, "Using provided hw_device_ctx\n");
> +    } else {
> +        ret = av_hwdevice_ctx_create(&dda->device_ref, AV_HWDEVICE_TYPE_D3D11VA, NULL, NULL, 0);
> +        if (ret < 0) {
> +            av_log(avctx, AV_LOG_ERROR, "Failed to create D3D11VA device.\n");
> +            return ret;
> +        }
> +
> +        dda->device_ctx = (AVHWDeviceContext*)dda->device_ref->data;
> +
> +        av_log(avctx, AV_LOG_VERBOSE, "Created internal hw_device_ctx\n");
> +    }
> +
> +    dda->device_hwctx = (AVD3D11VADeviceContext*)dda->device_ctx->hwctx;
> +
> +    ret = init_dxgi_dda(avctx);
> +    if (ret < 0)
> +        goto fail;
> +
> +    if (dda->width <= 0)
> +        dda->width = dda->raw_width;
> +    if (dda->height <= 0)
> +        dda->height = dda->raw_height;
> +
> +    dda->width -= FFMAX(dda->width - dda->raw_width + dda->offset_x, 0);
> +    dda->height -= FFMAX(dda->height - dda->raw_height + dda->offset_y, 0);
> +
> +    dda->time_base  = av_inv_q(dda->framerate);
> +    dda->time_frame = av_gettime_relative() / av_q2d(dda->time_base);
> +    dda->time_timeout = av_rescale_q(1, dda->time_base, (AVRational) { 1, 1000 }) / 2;
> +
> +    dda->last_frame = av_frame_alloc();
> +    if (!dda->last_frame) {
> +        ret = AVERROR(ENOMEM);
> +        goto fail;
> +    }
> +
> +    dda->mouse_x = -1;
> +    dda->mouse_y = -1;
> +
> +    if (dda->draw_mouse) {
> +        ret = init_render_resources(avctx);
> +        if (ret < 0)
> +            goto fail;
> +    }
> +
> +    return 0;
> +fail:
> +    ddagrab_uninit(avctx);
> +    return ret;
> +}
> +
> +static int create_d3d11_pointer_tex(AVFilterContext *avctx,
> +                                    uint8_t *buf,
> +                                    DXGI_OUTDUPL_POINTER_SHAPE_INFO *shape_info,
> +                                    ID3D11Texture2D **out_tex,
> +                                    ID3D11ShaderResourceView **res_view)
> +{
> +    DdagrabContext *dda = avctx->priv;
> +    D3D11_TEXTURE2D_DESC desc = { 0 };
> +    D3D11_SUBRESOURCE_DATA init_data = { 0 };
> +    D3D11_SHADER_RESOURCE_VIEW_DESC resource_desc = { 0 };
> +    HRESULT hr;
> +
> +    desc.MipLevels = 1;
> +    desc.ArraySize = 1;
> +    desc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
> +    desc.SampleDesc.Count = 1;
> +    desc.SampleDesc.Quality = 0;
> +    desc.Usage = D3D11_USAGE_IMMUTABLE;
> +    desc.BindFlags = D3D11_BIND_SHADER_RESOURCE;
> +
> +    desc.Width = shape_info->Width;
> +    desc.Height = shape_info->Height;
> +
> +    init_data.pSysMem = buf;
> +    init_data.SysMemPitch = shape_info->Pitch;
> +
> +    resource_desc.Format = desc.Format;
> +    resource_desc.ViewDimension = D3D11_SRV_DIMENSION_TEXTURE2D;
> +    resource_desc.Texture2D.MostDetailedMip = 0;
> +    resource_desc.Texture2D.MipLevels = 1;
> +
> +    hr = ID3D11Device_CreateTexture2D(dda->device_hwctx->device,
> +        &desc,
> +        &init_data,
> +        out_tex);
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "Failed creating pointer texture\n");
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    hr = ID3D11Device_CreateShaderResourceView(dda->device_hwctx->device,
> +        (ID3D11Resource*)dda->mouse_texture,
> +        &resource_desc,
> +        res_view);
> +    if (FAILED(hr)) {
> +        release_resource(out_tex);
> +        av_log(avctx, AV_LOG_ERROR, "CreateShaderResourceView for mouse failed: %lx\n", hr);
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    return 0;
> +}
> +
> +static uint8_t *convert_mono_buffer(uint8_t *input, int *_width, int *_height, int *_pitch)
> +{
> +    int width = *_width, height = *_height, pitch = *_pitch;
> +    int real_height = height / 2;
> +    uint8_t *output = av_malloc(real_height * width * 4);
> +    int y, x;
> +
> +    if (!output)
> +        return NULL;
> +
> +    // This simulates drawing the cursor on a full black surface
> +    // i.e. ignore the AND mask, turn XOR mask into all 4 color channels
> +    for (y = 0; y < real_height; y++) {
> +        for (x = 0; x < width; x++) {
> +            int v = input[(real_height + y) * pitch + (x / 8)];
> +            v = (v >> (7 - (x % 8))) & 1;
> +            memset(&output[4 * ((y*width) + x)], v ? 0xFF : 0, 4);
> +        }
> +    }
> +
> +    *_pitch = width * 4;
> +    *_height = real_height;
> +
> +    return output;
> +}
> +
> +static void fixup_color_mask(uint8_t *buf, int width, int height, int pitch)
> +{
> +    int x, y;
> +    // There is no good way to replicate XOR'ig parts of the texture with the screen
> +    // best effort is rendering the non-masked parts, and make the rest transparent
> +    for (y = 0; y < height; y++) {
> +        for (x = 0; x < width; x++) {
> +            int pos = (y*pitch) + (4*x) + 3;
> +            buf[pos] = buf[pos] ? 0 : 0xFF;
> +        }
> +    }
> +}
> +
> +static int update_mouse_pointer(AVFilterContext *avctx, DXGI_OUTDUPL_FRAME_INFO *frame_info)
> +{
> +    DdagrabContext *dda = avctx->priv;
> +    HRESULT hr;
> +    int ret;
> +
> +    if (frame_info->LastMouseUpdateTime.QuadPart == 0)
> +        return 0;
> +
> +    if (frame_info->PointerPosition.Visible) {
> +        dda->mouse_x = frame_info->PointerPosition.Position.x;
> +        dda->mouse_y = frame_info->PointerPosition.Position.y;
> +    } else {
> +        dda->mouse_x = dda->mouse_y = -1;
> +    }
> +
> +    if (frame_info->PointerShapeBufferSize) {
> +        UINT size = frame_info->PointerShapeBufferSize;
> +        DXGI_OUTDUPL_POINTER_SHAPE_INFO shape_info;
> +        uint8_t *buf = av_malloc(size);
> +        if (!buf)
> +            return AVERROR(ENOMEM);
> +
> +        hr = IDXGIOutputDuplication_GetFramePointerShape(dda->dxgi_outdupl,
> +            size,
> +            buf,
> +            &size,
> +            &shape_info);
> +        if (FAILED(hr)) {
> +            av_free(buf);
> +            av_log(avctx, AV_LOG_ERROR, "Failed getting pointer shape: %lx\n", hr);
> +            return AVERROR_EXTERNAL;
> +        }
> +
> +        if (shape_info.Type == DXGI_OUTDUPL_POINTER_SHAPE_TYPE_MONOCHROME) {
> +            uint8_t *new_buf = convert_mono_buffer(buf, &shape_info.Width, &shape_info.Height, &shape_info.Pitch);
> +            av_free(buf);
> +            if (!new_buf)
> +                return AVERROR(ENOMEM);
> +            buf = new_buf;
> +        } else if (shape_info.Type == DXGI_OUTDUPL_POINTER_SHAPE_TYPE_MASKED_COLOR) {
> +            fixup_color_mask(buf, shape_info.Width, shape_info.Height, shape_info.Pitch);
> +        } else if (shape_info.Type != DXGI_OUTDUPL_POINTER_SHAPE_TYPE_COLOR) {
> +            av_log(avctx, AV_LOG_WARNING, "Unsupported pointer shape type: %d\n", (int)shape_info.Type);
> +            av_free(buf);
> +            return 0;
> +        }
> +
> +        release_resource(&dda->mouse_resource_view);
> +        release_resource(&dda->mouse_texture);
> +
> +        ret = create_d3d11_pointer_tex(avctx, buf, &shape_info, &dda->mouse_texture, &dda->mouse_resource_view);
> +        av_freep(&buf);
> +        if (ret < 0)
> +            return ret;
> +
> +        av_log(avctx, AV_LOG_VERBOSE, "Updated pointer shape texture\n");
> +    }
> +
> +    return 0;
> +}
> +
> +static int next_frame_internal(AVFilterContext *avctx, ID3D11Texture2D **desktop_texture)
> +{
> +    DXGI_OUTDUPL_FRAME_INFO frame_info;
> +    DdagrabContext *dda = avctx->priv;
> +    IDXGIResource *desktop_resource = NULL;
> +    HRESULT hr;
> +    int ret;
> +
> +    hr = IDXGIOutputDuplication_AcquireNextFrame(
> +        dda->dxgi_outdupl,
> +        dda->time_timeout,
> +        &frame_info,
> +        &desktop_resource);
> +    if (hr == DXGI_ERROR_WAIT_TIMEOUT) {
> +        return AVERROR(EAGAIN);
> +    } else if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "AcquireNextFrame failed: %lx\n", hr);
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    if (dda->draw_mouse) {
> +        ret = update_mouse_pointer(avctx, &frame_info);
> +        if (ret < 0)
> +            return ret;
> +    }
> +
> +    hr = IDXGIResource_QueryInterface(desktop_resource, &IID_ID3D11Texture2D, (void**)desktop_texture);
> +    IDXGIResource_Release(desktop_resource);
> +    desktop_resource = NULL;
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "DXGIResource QueryInterface failed\n");
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    return 0;
> +}
> +
> +static int probe_output_format(AVFilterContext *avctx)
> +{
> +    DdagrabContext *dda = avctx->priv;
> +    D3D11_TEXTURE2D_DESC desc;
> +    int ret;
> +
> +    av_assert1(!dda->probed_texture);
> +
> +    do {
> +        ret = next_frame_internal(avctx, &dda->probed_texture);
> +    } while(ret == AVERROR(EAGAIN));
> +    if (ret < 0)
> +        return ret;
> +
> +    ID3D11Texture2D_GetDesc(dda->probed_texture, &desc);
> +
> +    dda->raw_format = desc.Format;
> +
> +    return 0;
> +}
> +
> +static av_cold int init_hwframes_ctx(AVFilterContext *avctx)
> +{
> +    DdagrabContext *dda = avctx->priv;
> +    int ret = 0;
> +
> +    dda->frames_ref = av_hwframe_ctx_alloc(dda->device_ref);
> +    if (!dda->frames_ref)
> +        return AVERROR(ENOMEM);
> +    dda->frames_ctx = (AVHWFramesContext*)dda->frames_ref->data;
> +    dda->frames_hwctx = (AVD3D11VAFramesContext*)dda->frames_ctx->hwctx;
> +
> +    dda->frames_ctx->format    = AV_PIX_FMT_D3D11;
> +    dda->frames_ctx->width     = dda->width;
> +    dda->frames_ctx->height    = dda->height;
> +
> +    switch (dda->raw_format) {
> +    case DXGI_FORMAT_B8G8R8A8_UNORM:
> +        av_log(avctx, AV_LOG_VERBOSE, "Probed 8 bit RGB frame format\n");
> +        dda->frames_ctx->sw_format = AV_PIX_FMT_BGRA;
> +        break;
> +    case DXGI_FORMAT_R10G10B10A2_UNORM:
> +        av_log(avctx, AV_LOG_VERBOSE, "Probed 10 bit RGB frame format\n");
> +        dda->frames_ctx->sw_format = AV_PIX_FMT_X2BGR10;
> +        break;
> +    default:
> +        av_log(avctx, AV_LOG_ERROR, "Unexpected texture output format!\n");
> +        return AVERROR_BUG;
> +    }
> +
> +    if (dda->draw_mouse)
> +        dda->frames_hwctx->BindFlags |= D3D11_BIND_RENDER_TARGET;
> +
> +    ret = av_hwframe_ctx_init(dda->frames_ref);
> +    if (ret < 0) {
> +        av_log(avctx, AV_LOG_ERROR, "Failed to initialise hardware frames context: %d.\n", ret);
> +        goto fail;
> +    }
> +
> +    return 0;
> +fail:
> +    av_buffer_unref(&dda->frames_ref);
> +    return ret;
> +}
> +
> +static int ddagrab_config_props(AVFilterLink *outlink)
> +{
> +    AVFilterContext *avctx = outlink->src;
> +    DdagrabContext *dda = avctx->priv;
> +    int ret;
> +
> +    outlink->w = dda->width;
> +    outlink->h = dda->height;
> +    outlink->time_base = (AVRational){1, TIMER_RES};
> +    outlink->frame_rate = dda->framerate;
> +
> +    ret = probe_output_format(avctx);
> +    if (ret < 0)
> +        return ret;
> +
> +    ret = init_hwframes_ctx(avctx);
> +    if (ret < 0)
> +        return ret;
> +
> +    outlink->hw_frames_ctx = av_buffer_ref(dda->frames_ref);
> +    if (!outlink->hw_frames_ctx)
> +        return AVERROR(ENOMEM);
> +
> +    return 0;
> +}
> +
> +static int draw_mouse_pointer(AVFilterContext *avctx, AVFrame *frame)
> +{
> +    DdagrabContext *dda = avctx->priv;
> +    ID3D11DeviceContext *devctx = dda->device_hwctx->device_context;
> +    ID3D11Texture2D *frame_tex = (ID3D11Texture2D*)frame->data[0];
> +    D3D11_RENDER_TARGET_VIEW_DESC target_desc = { 0 };
> +    ID3D11RenderTargetView* target_view = NULL;
> +    ID3D11Buffer *mouse_vertex_buffer = NULL;
> +    D3D11_TEXTURE2D_DESC tex_desc;
> +    int num_vertices = 0;
> +    int x, y;
> +    HRESULT hr;
> +    int ret = 0;
> +
> +    if (!dda->mouse_texture || dda->mouse_x < 0 || dda->mouse_y < 0)
> +        return 0;
> +
> +    ID3D11Texture2D_GetDesc(dda->mouse_texture, &tex_desc);
> +
> +    x = dda->mouse_x - dda->offset_x;
> +    y = dda->mouse_y - dda->offset_y;
> +
> +    if (x >= dda->width || y >= dda->height ||
> +        -x >= (int)tex_desc.Width || -y >= (int)tex_desc.Height)
> +        return 0;
> +
> +    target_desc.Format = dda->raw_format;
> +    target_desc.ViewDimension = D3D11_RTV_DIMENSION_TEXTURE2D;
> +    target_desc.Texture2D.MipSlice = 0;
> +
> +    hr = ID3D11Device_CreateRenderTargetView(dda->device_hwctx->device,
> +        (ID3D11Resource*)frame_tex,
> +        &target_desc,
> +        &target_view);
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "CreateRenderTargetView failed: %lx\n", hr);
> +        ret = AVERROR_EXTERNAL;
> +        goto end;
> +    }
> +
> +    ID3D11DeviceContext_ClearState(devctx);
> +
> +    {
> +        D3D11_VIEWPORT viewport = { 0 };
> +        viewport.Width = dda->width;
> +        viewport.Height = dda->height;
> +        viewport.MinDepth = 0.0f;
> +        viewport.MaxDepth = 1.0f;
> +
> +        ID3D11DeviceContext_RSSetViewports(devctx, 1, &viewport);
> +    }
> +
> +    {
> +        FLOAT vertices[] = {
> +            // x, y, z,  u, v
> +            x                 , y + tex_desc.Height, 0.0f,  0.0f, 1.0f,
> +            x                 , y                  , 0.0f,  0.0f, 0.0f,
> +            x + tex_desc.Width, y + tex_desc.Height, 0.0f,  1.0f, 1.0f,
> +            x + tex_desc.Width, y                  , 0.0f,  1.0f, 0.0f,
> +        };
> +        UINT stride = sizeof(FLOAT) * 5;
> +        UINT offset = 0;
> +
> +        D3D11_SUBRESOURCE_DATA init_data = { 0 };
> +        D3D11_BUFFER_DESC buf_desc = { 0 };
> +
> +        num_vertices = sizeof(vertices) / (sizeof(FLOAT) * 5);
> +
> +        buf_desc.Usage = D3D11_USAGE_DEFAULT;
> +        buf_desc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
> +        buf_desc.ByteWidth = sizeof(vertices);
> +        init_data.pSysMem = vertices;
> +
> +        hr = ID3D11Device_CreateBuffer(dda->device_hwctx->device,
> +            &buf_desc,
> +            &init_data,
> +            &mouse_vertex_buffer);
> +        if (FAILED(hr)) {
> +            av_log(avctx, AV_LOG_ERROR, "CreateBuffer failed: %lx\n", hr);
> +            ret = AVERROR_EXTERNAL;
> +            goto end;
> +        }
> +
> +        ID3D11DeviceContext_IASetVertexBuffers(devctx, 0, 1, &mouse_vertex_buffer, &stride, &offset);
> +        ID3D11DeviceContext_IASetInputLayout(devctx, dda->input_layout);
> +        ID3D11DeviceContext_IASetPrimitiveTopology(devctx, D3D11_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);
> +    }
> +
> +    ID3D11DeviceContext_VSSetShader(devctx, dda->vertex_shader, NULL, 0);
> +    ID3D11DeviceContext_VSSetConstantBuffers(devctx, 0, 1, &dda->const_buffer);
> +    ID3D11DeviceContext_PSSetSamplers(devctx, 0, 1, &dda->sampler_state);
> +    ID3D11DeviceContext_PSSetShaderResources(devctx, 0, 1, &dda->mouse_resource_view);
> +    ID3D11DeviceContext_PSSetShader(devctx, dda->pixel_shader, NULL, 0);
> +
> +    ID3D11DeviceContext_OMSetBlendState(devctx, dda->blend_state, NULL, 0xFFFFFFFF);
> +    ID3D11DeviceContext_OMSetRenderTargets(devctx, 1, &target_view, NULL);
> +
> +    ID3D11DeviceContext_Draw(devctx, num_vertices, 0);
> +
> +end:
> +    release_resource(&mouse_vertex_buffer);
> +    release_resource(&target_view);
> +
> +    return ret;
> +}
> +
> +static int ddagrab_request_frame(AVFilterLink *outlink)
> +{
> +    AVFilterContext *avctx = outlink->src;
> +    DdagrabContext *dda = avctx->priv;
> +
> +    ID3D11Texture2D *cur_texture = NULL;
> +    D3D11_TEXTURE2D_DESC desc = { 0 };
> +    D3D11_BOX box = { 0 };
> +
> +    int64_t time_frame = dda->time_frame;
> +    int64_t now, delay;
> +    AVFrame *frame = NULL;
> +    HRESULT hr;
> +    int ret;
> +
> +    /* time_frame is in units of microseconds divided by the time_base.
> +     * This means that adding a clean 1M to it is the equivalent of adding
> +     * 1M*time_base microseconds to it, except it avoids all rounding error.
> +     * The only time rounding error occurs is when multiplying to calculate
> +     * the delay. So any rounding error there corrects itself over time.
> +     */
> +    time_frame += TIMER_RES64;
> +    for (;;) {
> +        now = av_gettime_relative();
> +        delay = time_frame * av_q2d(dda->time_base) - now;
> +        if (delay <= 0) {
> +            if (delay < -TIMER_RES64 * av_q2d(dda->time_base)) {
> +                time_frame += TIMER_RES64;
> +            }
> +            break;
> +        }
> +        av_usleep(delay);
> +    }
> +
> +    if (!dda->first_pts)
> +        dda->first_pts = now;
> +    now -= dda->first_pts;
> +
> +    if (!dda->probed_texture) {
> +        ret = next_frame_internal(avctx, &cur_texture);
> +    } else {
> +        cur_texture = dda->probed_texture;
> +        dda->probed_texture = NULL;
> +        ret = 0;
> +    }
> +
> +    if (ret == AVERROR(EAGAIN) && dda->last_frame->buf[0]) {
> +        frame = av_frame_alloc();
> +        if (!frame)
> +            return AVERROR(ENOMEM);
> +
> +        ret = av_frame_ref(frame, dda->last_frame);
> +        if (ret < 0) {
> +            av_frame_free(&frame);
> +            return ret;
> +        }
> +
> +        av_log(avctx, AV_LOG_DEBUG, "Duplicated output frame\n");
> +
> +        goto frame_done;
> +    } else if (ret == AVERROR(EAGAIN)) {
> +        av_log(avctx, AV_LOG_VERBOSE, "Initial DDA AcquireNextFrame timeout!\n");
> +        return AVERROR(EAGAIN);
> +    } else if (ret < 0) {
> +        return ret;
> +    }
> +
> +    // AcquireNextFrame sometimes has bursts of delay.
> +    // This increases accuracy of the timestamp, but might upset consumers due to more jittery framerate?
> +    now = av_gettime_relative() - dda->first_pts;
> +
> +    ID3D11Texture2D_GetDesc(cur_texture, &desc);
> +    if (desc.Format != dda->raw_format ||
> +        (int)desc.Width != dda->raw_width ||
> +        (int)desc.Height != dda->raw_height) {
> +        av_log(avctx, AV_LOG_ERROR, "Output parameters changed!");
> +        ret = AVERROR_OUTPUT_CHANGED;
> +        goto fail;
> +    }
> +
> +    frame = ff_get_video_buffer(outlink, dda->width, dda->height);
> +    if (!frame) {
> +        ret = AVERROR(ENOMEM);
> +        goto fail;
> +    }
> +
> +    box.left = dda->offset_x;
> +    box.top = dda->offset_y;
> +    box.right = box.left + dda->width;
> +    box.bottom = box.top + dda->height;
> +    box.front = 0;
> +    box.back = 1;
> +
> +    ID3D11DeviceContext_CopySubresourceRegion(
> +        dda->device_hwctx->device_context,
> +        (ID3D11Resource*)frame->data[0], (UINT)(intptr_t)frame->data[1],
> +        0, 0, 0,
> +        (ID3D11Resource*)cur_texture, 0,
> +        &box);
> +
> +    release_resource(&cur_texture);
> +
> +    hr = IDXGIOutputDuplication_ReleaseFrame(dda->dxgi_outdupl);
> +    if (FAILED(hr)) {
> +        av_log(avctx, AV_LOG_ERROR, "DDA ReleaseFrame failed!\n");
> +        ret = AVERROR_EXTERNAL;
> +        goto fail;
> +    }
> +
> +    if (dda->draw_mouse) {
> +        ret = draw_mouse_pointer(avctx, frame);
> +        if (ret < 0)
> +            goto fail;
> +    }
> +
> +    frame->sample_aspect_ratio = (AVRational){1, 1};
> +
> +    av_frame_unref(dda->last_frame);
> +    ret = av_frame_ref(dda->last_frame, frame);
> +    if (ret < 0)
> +        return ret;
> +
> +frame_done:
> +    frame->pts = now;
> +    dda->time_frame = time_frame;
> +
> +    return ff_filter_frame(outlink, frame);
> +
> +fail:
> +    if (frame)
> +        av_frame_free(&frame);
> +
> +    if (cur_texture)
> +        IDXGIOutputDuplication_ReleaseFrame(dda->dxgi_outdupl);
> +
> +    release_resource(&cur_texture);
> +    return ret;
> +}
> +
> +static const AVFilterPad ddagrab_outputs[] = {
> +    {
> +        .name          = "default",
> +        .type          = AVMEDIA_TYPE_VIDEO,
> +        .request_frame = ddagrab_request_frame,
> +        .config_props  = ddagrab_config_props,
> +    },
> +};
> +
> +const AVFilter ff_vsrc_ddagrab = {
> +    .name          = "ddagrab",
> +    .description   = NULL_IF_CONFIG_SMALL("Grab Windows Desktop images using Desktop Duplication API"),
> +    .priv_size     = sizeof(DdagrabContext),
> +    .priv_class    = &ddagrab_class,
> +    .init          = ddagrab_init,
> +    .uninit        = ddagrab_uninit,
> +    .inputs        = NULL,
> +    FILTER_OUTPUTS(ddagrab_outputs),
> +    FILTER_SINGLE_PIXFMT(AV_PIX_FMT_D3D11),
> +    .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
> +};
> diff --git a/libavfilter/vsrc_ddagrab_shaders.h b/libavfilter/vsrc_ddagrab_shaders.h
> new file mode 100644
> index 0000000000..0305f8de1c
> --- /dev/null
> +++ b/libavfilter/vsrc_ddagrab_shaders.h
> @@ -0,0 +1,120 @@
> +/*
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg 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.
> + *
> + * FFmpeg 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 FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#ifndef AVFILTER_VSRC_DDAGRAB_SHADERS_H
> +#define AVFILTER_VSRC_DDAGRAB_SHADERS_H
> +
> +#if 0
> +
> +cbuffer PARAMS : register ( b0 )
> +{
> +    float2 Dimensions;
> +};
> +
> +struct VS_INPUT
> +{
> +    float3 Pos : POSITION;
> +    float2 Tex : TEXCOORD;
> +};
> +
> +struct VS_OUTPUT
> +{
> +    float4 Pos : SV_POSITION;
> +    float2 Tex : TEXCOORD;
> +};
> +
> +VS_OUTPUT VS(VS_INPUT input)
> +{
> +    VS_OUTPUT output;
> +    float2 center = Dimensions / 2;
> +    output.Pos = float4((input.Pos.xy - center) / center, input.Pos.z, 1.0f);
> +    output.Pos.y *= -1;
> +    output.Tex = input.Tex;
> +    return output;
> +}
> +
> +Texture2D tx : register( t0 );
> +SamplerState samLinear : register( s0 );
> +
> +float4 PS(VS_OUTPUT input) : SV_Target
> +{
> +    return tx.Sample(samLinear, input.Tex);
> +}
> +
> +#endif
> +
> +static const uint8_t vertex_shader_bytes[] =
> +{
> +     68,  88,  66,  67, 207, 194, 142, 193, 255,  85,  32,  72, 116,  77, 242, 140,  26, 229,  67,  69,   1,   0,   0,   0,
> +     40,   3,   0,   0,   4,   0,   0,   0,  48,   0,   0,   0,  56,   1,   0,   0, 124,   2,   0,   0, 208,   2,   0,   0,
> +     65, 111, 110,  57,   0,   1,   0,   0,   0,   1,   0,   0,   0,   2, 254, 255, 204,   0,   0,   0,  52,   0,   0,   0,
> +      1,   0,  36,   0,   0,   0,  48,   0,   0,   0,  48,   0,   0,   0,  36,   0,   1,   0,  48,   0,   0,   0,   0,   0,
> +      1,   0,   1,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   2, 254, 255,  81,   0,   0,   5,   2,   0,  15, 160,
> +      0,   0,   0,  63,   0,   0, 128,  63,   0,   0,   0,   0,   0,   0,   0,   0,  31,   0,   0,   2,   5,   0,   0, 128,
> +      0,   0,  15, 144,  31,   0,   0,   2,   5,   0,   1, 128,   1,   0,  15, 144,   1,   0,   0,   2,   0,   0,   1, 128,
> +      2,   0,   0, 160,   4,   0,   0,   4,   0,   0,   6, 128,   1,   0, 208, 160,   0,   0,   0, 129,   0,   0, 208, 144,
> +      5,   0,   0,   3,   0,   0,   9, 128,   0,   0,   0, 128,   1,   0, 100, 160,   6,   0,   0,   2,   1,   0,   1, 128,
> +      0,   0,   0, 128,   6,   0,   0,   2,   1,   0,   2, 128,   0,   0, 255, 128,   5,   0,   0,   3,   0,   0,   3, 128,
> +      0,   0, 233, 128,   1,   0, 228, 128,   1,   0,   0,   2,   0,   0,   4, 128,   0,   0,  85, 129,   2,   0,   0,   3,
> +      0,   0,   3, 192,   0,   0, 232, 128,   0,   0, 228, 160,   4,   0,   0,   4,   0,   0,  12, 192,   0,   0, 170, 144,
> +      2,   0, 148, 160,   2,   0, 100, 160,   1,   0,   0,   2,   0,   0,   3, 224,   1,   0, 228, 144, 255, 255,   0,   0,
> +     83,  72,  68,  82,  60,   1,   0,   0,  64,   0,   1,   0,  79,   0,   0,   0,  89,   0,   0,   4,  70, 142,  32,   0,
> +      0,   0,   0,   0,   1,   0,   0,   0,  95,   0,   0,   3, 114,  16,  16,   0,   0,   0,   0,   0,  95,   0,   0,   3,
> +     50,  16,  16,   0,   1,   0,   0,   0, 103,   0,   0,   4, 242,  32,  16,   0,   0,   0,   0,   0,   1,   0,   0,   0,
> +    101,   0,   0,   3,  50,  32,  16,   0,   1,   0,   0,   0, 104,   0,   0,   2,   1,   0,   0,   0,  56,   0,   0,  11,
> +     50,   0,  16,   0,   0,   0,   0,   0,  70, 128,  32,   0,   0,   0,   0,   0,   0,   0,   0,   0,   2,  64,   0,   0,
> +      0,   0,   0,  63,   0,   0,   0,  63,   0,   0,   0,   0,   0,   0,   0,   0,  50,   0,   0,  14, 194,   0,  16,   0,
> +      0,   0,   0,   0,   6, 132,  32, 128,  65,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   2,  64,   0,   0,
> +      0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,  63,   0,   0,   0,  63,   6,  20,  16,   0,   0,   0,   0,   0,
> +     14,   0,   0,   7,  50,   0,  16,   0,   0,   0,   0,   0, 230,  10,  16,   0,   0,   0,   0,   0,  70,   0,  16,   0,
> +      0,   0,   0,   0,  56,   0,   0,  10,  50,  32,  16,   0,   0,   0,   0,   0,  70,   0,  16,   0,   0,   0,   0,   0,
> +      2,  64,   0,   0,   0,   0, 128,  63,   0,   0, 128, 191,   0,   0,   0,   0,   0,   0,   0,   0,  54,   0,   0,   5,
> +     66,  32,  16,   0,   0,   0,   0,   0,  42,  16,  16,   0,   0,   0,   0,   0,  54,   0,   0,   5, 130,  32,  16,   0,
> +      0,   0,   0,   0,   1,  64,   0,   0,   0,   0, 128,  63,  54,   0,   0,   5,  50,  32,  16,   0,   1,   0,   0,   0,
> +     70,  16,  16,   0,   1,   0,   0,   0,  62,   0,   0,   1,  73,  83,  71,  78,  76,   0,   0,   0,   2,   0,   0,   0,
> +      8,   0,   0,   0,  56,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   3,   0,   0,   0,   0,   0,   0,   0,
> +      7,   7,   0,   0,  65,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   3,   0,   0,   0,   1,   0,   0,   0,
> +      3,   3,   0,   0,  80,  79,  83,  73,  84,  73,  79,  78,   0,  84,  69,  88,  67,  79,  79,  82,  68,   0, 171, 171,
> +     79,  83,  71,  78,  80,   0,   0,   0,   2,   0,   0,   0,   8,   0,   0,   0,  56,   0,   0,   0,   0,   0,   0,   0,
> +      1,   0,   0,   0,   3,   0,   0,   0,   0,   0,   0,   0,  15,   0,   0,   0,  68,   0,   0,   0,   0,   0,   0,   0,
> +      0,   0,   0,   0,   3,   0,   0,   0,   1,   0,   0,   0,   3,  12,   0,   0,  83,  86,  95,  80,  79,  83,  73,  84,
> +     73,  79,  78,   0,  84,  69,  88,  67,  79,  79,  82,  68,   0, 171, 171, 171
> +};
> +
> +static const uint8_t pixel_shader_bytes[] =
> +{
> +     68,  88,  66,  67,   0,  95,  83, 169,  90,  60, 208,  75, 219, 179, 108, 203,   8, 232, 255,  27,   1,   0,   0,   0,
> +    148,   1,   0,   0,   4,   0,   0,   0,  48,   0,   0,   0, 156,   0,   0,   0,   8,   1,   0,   0,  96,   1,   0,   0,
> +     65, 111, 110,  57, 100,   0,   0,   0, 100,   0,   0,   0,   0,   2, 255, 255,  60,   0,   0,   0,  40,   0,   0,   0,
> +      0,   0,  40,   0,   0,   0,  40,   0,   0,   0,  40,   0,   1,   0,  36,   0,   0,   0,  40,   0,   0,   0,   0,   0,
> +      0,   2, 255, 255,  31,   0,   0,   2,   0,   0,   0, 128,   0,   0,   3, 176,  31,   0,   0,   2,   0,   0,   0, 144,
> +      0,   8,  15, 160,  66,   0,   0,   3,   0,   0,  15, 128,   0,   0, 228, 176,   0,   8, 228, 160,   1,   0,   0,   2,
> +      0,   8,  15, 128,   0,   0, 228, 128, 255, 255,   0,   0,  83,  72,  68,  82, 100,   0,   0,   0,  64,   0,   0,   0,
> +     25,   0,   0,   0,  90,   0,   0,   3,   0,  96,  16,   0,   0,   0,   0,   0,  88,  24,   0,   4,   0, 112,  16,   0,
> +      0,   0,   0,   0,  85,  85,   0,   0,  98,  16,   0,   3,  50,  16,  16,   0,   1,   0,   0,   0, 101,   0,   0,   3,
> +    242,  32,  16,   0,   0,   0,   0,   0,  69,   0,   0,   9, 242,  32,  16,   0,   0,   0,   0,   0,  70,  16,  16,   0,
> +      1,   0,   0,   0,  70, 126,  16,   0,   0,   0,   0,   0,   0,  96,  16,   0,   0,   0,   0,   0,  62,   0,   0,   1,
> +     73,  83,  71,  78,  80,   0,   0,   0,   2,   0,   0,   0,   8,   0,   0,   0,  56,   0,   0,   0,   0,   0,   0,   0,
> +      1,   0,   0,   0,   3,   0,   0,   0,   0,   0,   0,   0,  15,   0,   0,   0,  68,   0,   0,   0,   0,   0,   0,   0,
> +      0,   0,   0,   0,   3,   0,   0,   0,   1,   0,   0,   0,   3,   3,   0,   0,  83,  86,  95,  80,  79,  83,  73,  84,
> +     73,  79,  78,   0,  84,  69,  88,  67,  79,  79,  82,  68,   0, 171, 171, 171,  79,  83,  71,  78,  44,   0,   0,   0,
> +      1,   0,   0,   0,   8,   0,   0,   0,  32,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   3,   0,   0,   0,
> +      0,   0,   0,   0,  15,   0,   0,   0,  83,  86,  95,  84,  97, 114, 103, 101, 116,   0, 171, 171
> +};
> +
> +#endif

On 09.07.2022 07:01, Gyan Doshi wrote:
> 
> 
> On 2022-07-09 04:24 am, Timo Rothenpieler wrote:
>> ---
>>   Changelog                          |   1 +
>>   configure                          |   7 +
>>   doc/filters.texi                   |  68 ++
>>   libavfilter/Makefile               |   1 +
>>   libavfilter/allfilters.c           |   1 +
>>   libavfilter/version.h              |   2 +-
>>   libavfilter/vsrc_ddagrab.c         | 980 +++++++++++++++++++++++++++++
>>   libavfilter/vsrc_ddagrab_shaders.h | 120 ++++
>>   8 files changed, 1179 insertions(+), 1 deletion(-)
>>   create mode 100644 libavfilter/vsrc_ddagrab.c
>>   create mode 100644 libavfilter/vsrc_ddagrab_shaders.h
>>
>> diff --git a/Changelog b/Changelog
>> index 1a7c84b7f8..9467e92dd1 100644
>> --- a/Changelog
>> +++ b/Changelog
>> @@ -24,6 +24,7 @@ version 5.1:
>>   - VDPAU AV1 hwaccel
>>   - PHM image format support
>>   - remap_opencl filter
>> +- ddagrab (Desktop Duplication) video source filter
> 
> The source filters are all generative filters. This should be called a 
> capture filter.
> Why is it a filter instead of in lavd?

lavd has no infrastructure for hardware acceleration whatsoever, and 
returns packets, not frames.
There'd be no way to access the likes of -init_hw_device from lavd.

And it also seems pointless an extra indirection to put something that 
produces frames into lavd.
With the included patch for lavfi.c you can use it via lavd if you 
really want to.
Though you give up any control over the created hwdevice context.