/*****************************************************************************
 * dxva2.c: Video Acceleration helpers
 *****************************************************************************
 * Copyright (C) 2009 Geoffroy Couprie
 * Copyright (C) 2009 Laurent Aimar
 *
 * Authors: Geoffroy Couprie <geal@videolan.org>
 *          Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
 *
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <assert.h>

#include <vlc_common.h>
#include <vlc_picture.h>
#include <vlc_plugin.h>

#define DXVA2API_USE_BITFIELDS
#define COBJMACROS
#include <libavcodec/dxva2.h>
#include "../../video_chroma/d3d9_fmt.h"

struct dxva2_pic_context
{
    struct d3d9_pic_context ctx;
    struct vlc_va_surface_t *va_surface;
    HINSTANCE               dxva2_dll;
};

#define DXVA2_PICCONTEXT_FROM_PICCTX(pic_ctx)  \
    container_of((pic_ctx), struct dxva2_pic_context, ctx.s)

#include "directx_va.h"

static int Open(vlc_va_t *, AVCodecContext *, enum AVPixelFormat hwfmt, const AVPixFmtDescriptor *,
                const es_format_t *, vlc_decoder_device *, video_format_t *, vlc_video_context **);

vlc_module_begin()
    set_description(N_("DirectX Video Acceleration (DXVA) 2.0"))
    set_subcategory(SUBCAT_INPUT_VCODEC)
    set_va_callback(Open, 110)
vlc_module_end()


/* */
typedef struct {
    const char   *name;
    D3DFORMAT    format;
    vlc_fourcc_t codec;
} d3d9_format_t;
/* XXX Preferred format must come first */
static const d3d9_format_t d3d_formats[] = {
    { "YV12",   MAKEFOURCC('Y','V','1','2'),    VLC_CODEC_YV12 },
    { "NV12",   MAKEFOURCC('N','V','1','2'),    VLC_CODEC_NV12 },
    //{ "IMC3",   MAKEFOURCC('I','M','C','3'),    VLC_CODEC_YV12 },
    { "P010",   MAKEFOURCC('P','0','1','0'),    VLC_CODEC_P010 },
    { "AYUV",   MAKEFOURCC('A','Y','U','V'),    VLC_CODEC_YUVA },
    { "YUY2",   MAKEFOURCC('Y','U','Y','2'),    VLC_CODEC_YUYV },
    { "Y410",   MAKEFOURCC('Y','4','1','0'),    VLC_CODEC_Y410 },
    { "Y210",   MAKEFOURCC('Y','2','1','0'),    VLC_CODEC_Y210 },

    { NULL, 0, 0 }
};

static const d3d9_format_t *D3dFindFormat(D3DFORMAT format)
{
    for (unsigned i = 0; d3d_formats[i].name; i++) {
        if (d3d_formats[i].format == format)
            return &d3d_formats[i];
    }
    return NULL;
}

typedef struct
{
    /* Direct3D */
    vlc_video_context      *vctx;

    /* DLL */
    HINSTANCE              dxva2_dll;

    /* Device manager */
    IDirect3DDeviceManager9  *devmng;
    HANDLE                   device;

    /* Video service */
    D3DFORMAT                    render;

    /* Video decoder */
    DXVA2_ConfigPictureDecode    cfg;
    const directx_va_mode_t       *selected_decoder;
    IDirectXVideoDecoderService  *d3ddec;

    /* pool */
    va_pool_t           *va_pool;
    IDirect3DSurface9   *hw_surface[MAX_SURFACE_COUNT];

    /* avcodec internals */
    struct dxva_context hw;
} vlc_va_sys_t;


/* */
static int D3dCreateDevice(vlc_va_t *);

static int DxGetInputList(vlc_va_t *, input_list_t *);
static int DxSetupOutput(vlc_va_t *, const directx_va_mode_t *, const video_format_t *);

static int DxCreateVideoDecoder(vlc_va_t *, int codec_id,
                                const video_format_t *, size_t surface_count);
static void DxDestroyVideoDecoder(void *);

static void SetupAVCodecContext(void *opaque, AVCodecContext *avctx)
{
    vlc_va_sys_t *sys = opaque;
    sys->hw.cfg = &sys->cfg;
    sys->hw.surface = sys->hw_surface;
    sys->hw.workaround = sys->selected_decoder->workaround;
    avctx->hwaccel_context = &sys->hw;
}

static void dxva2_pic_context_destroy(picture_context_t *ctx)
{
    struct dxva2_pic_context *pic_ctx = DXVA2_PICCONTEXT_FROM_PICCTX(ctx);
    struct vlc_va_surface_t *va_surface = pic_ctx->va_surface;
    HINSTANCE dxva2_dll = pic_ctx->dxva2_dll;
    static_assert(offsetof(struct dxva2_pic_context, ctx.s) == 0,
        "Cast assumption failure");
    d3d9_pic_context_destroy(ctx);
    va_surface_Release(va_surface);
    FreeLibrary(dxva2_dll);
}

static picture_context_t *dxva2_pic_context_copy(picture_context_t *ctx)
{
    struct dxva2_pic_context *src_ctx = DXVA2_PICCONTEXT_FROM_PICCTX(ctx);
    struct dxva2_pic_context *pic_ctx = malloc(sizeof(*pic_ctx));
    if (unlikely(pic_ctx==NULL))
        return NULL;
    *pic_ctx = *src_ctx;
    pic_ctx->dxva2_dll = LoadLibrary(TEXT("DXVA2.DLL"));
    vlc_video_context_Hold(pic_ctx->ctx.s.vctx);
    va_surface_AddRef(pic_ctx->va_surface);
    AcquireD3D9PictureSys(&pic_ctx->ctx.picsys);
    return &pic_ctx->ctx.s;
}

static struct dxva2_pic_context *CreatePicContext(IDirect3DSurface9 *surface, vlc_video_context *vctx)
{
    struct dxva2_pic_context *pic_ctx = calloc(1, sizeof(*pic_ctx));
    if (unlikely(pic_ctx==NULL))
        return NULL;
    pic_ctx->ctx.s = (picture_context_t) {
        dxva2_pic_context_destroy, dxva2_pic_context_copy,
        vlc_video_context_Hold(vctx),
    };
    pic_ctx->ctx.picsys.surface = surface;
    AcquireD3D9PictureSys(&pic_ctx->ctx.picsys);
    return pic_ctx;
}

static picture_context_t* NewSurfacePicContext(vlc_va_t *va, vlc_va_surface_t *va_surface)
{
    vlc_va_sys_t *sys = va->sys;
    struct dxva2_pic_context *pic_ctx = CreatePicContext(sys->hw_surface[va_surface_GetIndex(va_surface)], sys->vctx);
    if (unlikely(pic_ctx==NULL))
        return NULL;
    pic_ctx->va_surface = va_surface;
    pic_ctx->dxva2_dll = LoadLibrary(TEXT("DXVA2.DLL"));
    return &pic_ctx->ctx.s;
}

static int Get(vlc_va_t *va, picture_t *pic, AVCodecContext *ctx, AVFrame *frame)
{
    (void) ctx;
    vlc_va_sys_t *sys = va->sys;

    /* Check the device */
    HRESULT hr = IDirect3DDeviceManager9_TestDevice(sys->devmng, sys->device);
    if (FAILED(hr)) {
        if (hr == DXVA2_E_NEW_VIDEO_DEVICE)
            msg_Warn(va, "New video device detected.");
        else
            msg_Err(va, "device not usable. (hr=0x%lX)", hr);
        return VLC_EGENERIC;
    }

    vlc_va_surface_t *va_surface = va_pool_Get(sys->va_pool);
    if (unlikely(va_surface==NULL))
        return VLC_ENOENT;

    pic->context = NewSurfacePicContext(va, va_surface);
    if (unlikely(pic->context == NULL))
    {
        va_surface_Release(va_surface);
        return VLC_ENOENT;
    }
    frame->data[3] = (uint8_t*)DXVA2_PICCONTEXT_FROM_PICCTX(pic->context)->ctx.picsys.surface;
    return VLC_SUCCESS;
}

static void Close(vlc_va_t *va, AVCodecContext *ctx)
{
    vlc_va_sys_t *sys = va->sys;

    if (ctx)
        ctx->hwaccel_context = NULL;

    if (sys->vctx)
        vlc_video_context_Release(sys->vctx);

    if (sys->va_pool)
        va_pool_Close(sys->va_pool);
}

static const struct vlc_va_operations ops = { Get, Close, };

static int Open(vlc_va_t *va, AVCodecContext *ctx, enum AVPixelFormat hwfmt, const AVPixFmtDescriptor *desc,
                const es_format_t *fmt_in, vlc_decoder_device *dec_device,
                video_format_t *fmt_out, vlc_video_context **vtcx_out)
{
    int err = VLC_EGENERIC;

    if ( hwfmt != AV_PIX_FMT_DXVA2_VLD )
        return VLC_EGENERIC;

    d3d9_decoder_device_t *d3d9_decoder = GetD3D9OpaqueDevice( dec_device );
    if ( d3d9_decoder == NULL )
        return VLC_EGENERIC;
    assert(d3d9_decoder->d3ddev.dev != NULL); // coming from the decoder device

    ctx->hwaccel_context = NULL;

    vlc_va_sys_t *sys = calloc(1, sizeof (*sys));
    if (unlikely(sys == NULL))
        return VLC_ENOMEM;

    sys->vctx = vlc_video_context_Create( dec_device, VLC_VIDEO_CONTEXT_DXVA2,
                                          sizeof(d3d9_video_context_t), &d3d9_vctx_ops );
    if (likely(sys->vctx == NULL))
    {
        free( sys );
        return VLC_EGENERIC;
    }

    va->sys = sys;

    /* Load dll*/
    sys->dxva2_dll = LoadLibrary(TEXT("DXVA2.DLL"));
    if (!sys->dxva2_dll) {
        msg_Warn(va, "cannot load DXVA2 decoder DLL");
        if (sys->vctx)
            vlc_video_context_Release(sys->vctx);
        free( sys );
        return VLC_EGENERIC;
    }

    struct va_pool_cfg pool_cfg = {
        D3dCreateDevice,
        DxDestroyVideoDecoder,
        DxCreateVideoDecoder,
        SetupAVCodecContext,
        sys,
    };

    sys->va_pool = va_pool_Create(va, &pool_cfg);
    if (sys->va_pool == NULL)
    {
        err = VLC_EGENERIC;
        goto error;
    }

    video_format_t final_fmt = *fmt_out;
    static const directx_sys_t dx_sys = { DxGetInputList, DxSetupOutput };
    sys->selected_decoder = directx_va_Setup(va, &dx_sys, ctx, desc, fmt_in, 0,
                                             &final_fmt, &sys->hw.surface_count);
    if (sys->selected_decoder == NULL)
    {
        err = VLC_EGENERIC;
        goto error;
    }

    if (sys->render == MAKEFOURCC('P','0','1','0') ||
        sys->render == MAKEFOURCC('Y','4','1','0') ||
        sys->render == MAKEFOURCC('Y','2','1','0'))
        final_fmt.i_chroma = VLC_CODEC_D3D9_OPAQUE_10B;
    else
        final_fmt.i_chroma = VLC_CODEC_D3D9_OPAQUE;
    final_fmt.i_rmask = final_fmt.i_gmask = final_fmt.i_bmask = 0;
    err = va_pool_SetupDecoder(va, sys->va_pool, ctx, &final_fmt, sys->hw.surface_count);
    if (err != VLC_SUCCESS)
        goto error;

    const D3DADAPTER_IDENTIFIER9 *identifier = &d3d9_decoder->d3ddev.identifier;
    msg_Info(va, "Using DXVA2 (%.*s, vendor %s(%lx), device %lx, revision %lx)",
                (int)sizeof(identifier->Description), identifier->Description,
                DxgiVendorStr(identifier->VendorId), identifier->VendorId,
                identifier->DeviceId, identifier->Revision);

    d3d9_video_context_t *octx = GetD3D9ContextPrivate(sys->vctx);
    octx->format = sys->render;

    va->ops = &ops;
    *fmt_out = final_fmt;
    *vtcx_out = sys->vctx;
    return VLC_SUCCESS;

error:
    Close(va, ctx);
    return VLC_EGENERIC;
}
/* */

/**
 * It creates a Direct3D device usable for DXVA 2
 */
static int D3dCreateDevice(vlc_va_t *va)
{
    vlc_va_sys_t *sys = va->sys;

    d3d9_decoder_device_t *d3d9_decoder = GetD3D9OpaqueContext(sys->vctx);

    HRESULT (WINAPI *CreateDeviceManager9)(UINT *pResetToken,
                                           IDirect3DDeviceManager9 **);
    CreateDeviceManager9 =
      (void *)GetProcAddress(sys->dxva2_dll,
                             "DXVA2CreateDirect3DDeviceManager9");

    if (!CreateDeviceManager9) {
        msg_Err(va, "cannot load function");
        return VLC_EGENERIC;
    }
    msg_Dbg(va, "got CreateDeviceManager9");

    UINT token;
    if (FAILED(CreateDeviceManager9(&token, &sys->devmng))) {
        msg_Err(va, " OurDirect3DCreateDeviceManager9 failed");
        return VLC_EGENERIC;
    }
    msg_Dbg(va, "obtained IDirect3DDeviceManager9");

    HRESULT hr = IDirect3DDeviceManager9_ResetDevice(sys->devmng, d3d9_decoder->d3ddev.dev, token);
    if (FAILED(hr)) {
        msg_Err(va, "IDirect3DDeviceManager9_ResetDevice failed: 0x%lX)", hr);
        IDirect3DDeviceManager9_Release(sys->devmng);
        return VLC_EGENERIC;
    }

    hr = IDirect3DDeviceManager9_OpenDeviceHandle(sys->devmng, &sys->device);
    if (FAILED(hr)) {
        msg_Err(va, "OpenDeviceHandle failed");
        IDirect3DDeviceManager9_Release(sys->devmng);
        return VLC_EGENERIC;
    }

    void *pv;
    hr = IDirect3DDeviceManager9_GetVideoService(sys->devmng, sys->device,
                                        &IID_IDirectXVideoDecoderService, &pv);
    if (FAILED(hr)) {
        msg_Err(va, "GetVideoService failed");
        IDirect3DDeviceManager9_CloseDeviceHandle(sys->devmng, sys->device);
        IDirect3DDeviceManager9_Release(sys->devmng);
        return VLC_EGENERIC;
    }
    sys->d3ddec = pv;

    return VLC_SUCCESS;
}

static void ReleaseInputList(input_list_t *p_list)
{
    CoTaskMemFree(p_list->list);
}

static int DxGetInputList(vlc_va_t *va, input_list_t *p_list)
{
    vlc_va_sys_t *sys = va->sys;
    UINT input_count = 0;
    GUID *input_list = NULL;
    if (FAILED(IDirectXVideoDecoderService_GetDecoderDeviceGuids(sys->d3ddec,
                                                                 &input_count,
                                                                 &input_list))) {
        msg_Err(va, "IDirectXVideoDecoderService_GetDecoderDeviceGuids failed");
        return VLC_EGENERIC;
    }

    p_list->count = input_count;
    p_list->list = input_list;
    p_list->pf_release = ReleaseInputList;
    return VLC_SUCCESS;
}

static int DxSetupOutput(vlc_va_t *va, const directx_va_mode_t *mode, const video_format_t *fmt)
{
    VLC_UNUSED(fmt);
    vlc_va_sys_t *sys = va->sys;

    d3d9_decoder_device_t *d3d9_decoder = GetD3D9OpaqueContext(sys->vctx);

    const D3DADAPTER_IDENTIFIER9 *identifier = &d3d9_decoder->d3ddev.identifier;
    UINT driverBuild = identifier->DriverVersion.LowPart & 0xFFFF;
    if (identifier->VendorId == GPU_MANUFACTURER_INTEL && (identifier->DriverVersion.LowPart >> 16) >= 100)
    {
        /* new Intel driver format */
        driverBuild += ((identifier->DriverVersion.LowPart >> 16) - 100) * 1000;
    }
    if (!directx_va_canUseDecoder(va, identifier->VendorId, identifier->DeviceId,
                                  mode->guid, driverBuild))
    {
        msg_Warn(va, "GPU blocklisted for %s codec", mode->name);
        return VLC_EGENERIC;
    }

    int err = VLC_EGENERIC;
    UINT      output_count = 0;
    D3DFORMAT *output_list = NULL;
    if (FAILED(IDirectXVideoDecoderService_GetDecoderRenderTargets(sys->d3ddec,
                                                                   mode->guid,
                                                                   &output_count,
                                                                   &output_list))) {
        msg_Err(va, "IDirectXVideoDecoderService_GetDecoderRenderTargets failed");
        return VLC_EGENERIC;
    }

    for (unsigned j = 0; j < output_count; j++) {
        const D3DFORMAT f = output_list[j];
        const d3d9_format_t *format = D3dFindFormat(f);
        if (format) {
            msg_Dbg(va, "%s is supported for output", format->name);
        } else {
            msg_Dbg(va, "%d is supported for output (%4.4s)", f, (const char*)&f);
        }
    }

    D3DFORMAT preferredOutput;
    if (mode->bit_depth > 8)
    {
        if (mode->log2_chroma_w == 0 && mode->log2_chroma_h == 0)
            preferredOutput = MAKEFOURCC('Y','4','1','0'); // 10 bits 4:4:4
        else if (mode->log2_chroma_w == 1 && mode->log2_chroma_h == 0)
            preferredOutput = MAKEFOURCC('Y','2','1','0'); // 10 bits 4:2:2
        else
            preferredOutput = MAKEFOURCC('P','0','1','0');
    }
    else if (mode->log2_chroma_w == 0 && mode->log2_chroma_h == 0)
        preferredOutput = MAKEFOURCC('A','Y','U','V'); // 8 bits 4:4:4
    else if (mode->log2_chroma_w == 1 && mode->log2_chroma_h == 0)
        preferredOutput = MAKEFOURCC('Y','U','Y','2'); // 8 bits 4:2:2
    else
        preferredOutput =  MAKEFOURCC('N','V','1','2');
    msg_Dbg(va, "favor decoder format %4.4s (for 4:%d:%d %d bits)", (const char*)&preferredOutput,
            (2-mode->log2_chroma_w)*2, (2-mode->log2_chroma_w-mode->log2_chroma_h)*2, mode->bit_depth);

    /* */
    for (unsigned pass = 0; pass < 2 && err != VLC_SUCCESS; ++pass)
    {
        for (unsigned j = 0; d3d_formats[j].name; j++) {
            const d3d9_format_t *format = &d3d_formats[j];

            /* */
            bool is_supported = false;
            for (unsigned k = 0; !is_supported && k < output_count; k++) {
                is_supported = format->format == output_list[k];
            }
            if (!is_supported)
                continue;
            if (pass == 0 && format->format != preferredOutput)
                continue;

            /* We have our solution */
            msg_Dbg(va, "Using decoder output '%s'", format->name);
            sys->render = format->format;
            err = VLC_SUCCESS;
            break;
        }
    }
    CoTaskMemFree(output_list);
    return err;
}

/**
 * It creates a DXVA2 decoder using the given video format
 */
static int DxCreateVideoDecoder(vlc_va_t *va, int codec_id,
                                const video_format_t *fmt, size_t surface_count)
{
    vlc_va_sys_t *sys = va->sys;
    HRESULT hr;

    hr = IDirectXVideoDecoderService_CreateSurface(sys->d3ddec,
                                                         fmt->i_width,
                                                         fmt->i_height,
                                                         surface_count - 1,
                                                         sys->render,
                                                         D3DPOOL_DEFAULT,
                                                         0,
                                                         DXVA2_VideoDecoderRenderTarget,
                                                         sys->hw_surface,
                                                         NULL);
    if (FAILED(hr)) {
        msg_Err(va, "IDirectXVideoAccelerationService_CreateSurface %zu failed (hr=0x%lX)", surface_count - 1, hr);
        return VLC_EGENERIC;
    }
    msg_Dbg(va, "IDirectXVideoAccelerationService_CreateSurface succeed with %zu surfaces (%dx%d)",
            surface_count, fmt->i_width, fmt->i_height);

    IDirect3DSurface9 *tstCrash;
    hr = IDirectXVideoDecoderService_CreateSurface(sys->d3ddec,
                                                         fmt->i_width,
                                                         fmt->i_height,
                                                         0,
                                                         sys->render,
                                                         D3DPOOL_DEFAULT,
                                                         0,
                                                         DXVA2_VideoDecoderRenderTarget,
                                                         &tstCrash,
                                                         NULL);
    if (FAILED(hr)) {
        msg_Err(va, "extra buffer impossible, avoid a crash (hr=0x%lX)", hr);
        goto error;
    }
    IDirect3DSurface9_Release(tstCrash);

    /* */
    DXVA2_VideoDesc dsc;
    ZeroMemory(&dsc, sizeof(dsc));
    dsc.SampleWidth     = fmt->i_width;
    dsc.SampleHeight    = fmt->i_height;
    dsc.Format          = sys->render;
    if (fmt->i_frame_rate > 0 && fmt->i_frame_rate_base > 0) {
        dsc.InputSampleFreq.Numerator   = fmt->i_frame_rate;
        dsc.InputSampleFreq.Denominator = fmt->i_frame_rate_base;
    } else {
        dsc.InputSampleFreq.Numerator   = 0;
        dsc.InputSampleFreq.Denominator = 0;
    }
    dsc.OutputFrameFreq = dsc.InputSampleFreq;
    dsc.UABProtectionLevel = FALSE;
    dsc.Reserved = 0;

    /* FIXME I am unsure we can let unknown everywhere */
    DXVA2_ExtendedFormat *ext = &dsc.SampleFormat;
    ext->SampleFormat = 0;//DXVA2_SampleUnknown;
    ext->VideoChromaSubsampling = 0;//DXVA2_VideoChromaSubsampling_Unknown;
    ext->NominalRange = 0;//DXVA2_NominalRange_Unknown;
    ext->VideoTransferMatrix = 0;//DXVA2_VideoTransferMatrix_Unknown;
    ext->VideoLighting = 0;//DXVA2_VideoLighting_Unknown;
    ext->VideoPrimaries = 0;//DXVA2_VideoPrimaries_Unknown;
    ext->VideoTransferFunction = 0;//DXVA2_VideoTransFunc_Unknown;

    /* List all configurations available for the decoder */
    UINT                      cfg_count = 0;
    DXVA2_ConfigPictureDecode *cfg_list = NULL;
    hr = IDirectXVideoDecoderService_GetDecoderConfigurations(sys->d3ddec,
                                                              sys->selected_decoder->guid,
                                                              &dsc,
                                                              NULL,
                                                              &cfg_count,
                                                              &cfg_list);
    if (FAILED(hr)) {
        msg_Err(va, "IDirectXVideoDecoderService_GetDecoderConfigurations failed. (hr=0x%lX)", hr);
        goto error;
    }
    msg_Dbg(va, "we got %d decoder configurations", cfg_count);

    /* Select the best decoder configuration */
    int cfg_score = 0;
    for (unsigned i = 0; i < cfg_count; i++) {
        const DXVA2_ConfigPictureDecode *cfg = &cfg_list[i];

        /* */
        msg_Dbg(va, "configuration[%d] ConfigBitstreamRaw %d",
                i, cfg->ConfigBitstreamRaw);

        /* */
        int score;
        if (cfg->ConfigBitstreamRaw == 1)
            score = 1;
        else if (codec_id == AV_CODEC_ID_H264 && cfg->ConfigBitstreamRaw == 2)
            score = 2;
        else
            continue;
        if (IsEqualGUID(&cfg->guidConfigBitstreamEncryption, &DXVA_NoEncrypt))
            score += 16;

        if (cfg_score < score) {
            sys->cfg = *cfg;
            cfg_score = score;
        }
    }
    CoTaskMemFree(cfg_list);
    if (cfg_score <= 0) {
        msg_Err(va, "Failed to find a supported decoder configuration");
        goto error;
    }

    /* Create the decoder */
    /* adds a reference on each decoder surface */
    if (FAILED(IDirectXVideoDecoderService_CreateVideoDecoder(sys->d3ddec,
                                                              sys->selected_decoder->guid,
                                                              &dsc,
                                                              &sys->cfg,
                                                              sys->hw_surface,
                                                              surface_count,
                                                              &sys->hw.decoder))) {
        msg_Err(va, "IDirectXVideoDecoderService_CreateVideoDecoder failed");
        goto error;
    }

    msg_Dbg(va, "IDirectXVideoDecoderService_CreateVideoDecoder succeed");
    return VLC_SUCCESS;
error:
    for (size_t i = 0; i < surface_count; i++)
        IDirect3DSurface9_Release( sys->hw_surface[i] );
    return VLC_EGENERIC;
}

static void DxDestroyVideoDecoder(void *opaque)
{
    vlc_va_sys_t *sys = opaque;
    /* releases a reference on each decoder surface */
    if (sys->hw.decoder)
        IDirectXVideoDecoder_Release(sys->hw.decoder);
    if (sys->hw_surface[0])
    {
        for (unsigned i = 0; i < sys->hw.surface_count; i++)
            IDirect3DSurface9_Release(sys->hw_surface[i]);
    }
    IDirect3DDeviceManager9_CloseDeviceHandle(sys->devmng, sys->device);
    IDirectXVideoDecoderService_Release(sys->d3ddec);
    IDirect3DDeviceManager9_Release(sys->devmng);
    if (sys->dxva2_dll)
        FreeLibrary(sys->dxva2_dll);

    free(sys);
}
