/*
 * 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 <stdatomic.h>
#include <stdint.h>
#include <string.h>

#include <mfx/mfxvideo.h>

#include "config.h"

#if HAVE_PTHREADS
#include <pthread.h>
#endif

#define COBJMACROS
#if CONFIG_VAAPI
#include "hwcontext_vaapi.h"
#endif
#if CONFIG_D3D11VA
#include "hwcontext_d3d11va.h"
#endif
#if CONFIG_DXVA2
#include "hwcontext_dxva2.h"
#endif

#include "buffer.h"
#include "common.h"
#include "hwcontext.h"
#include "hwcontext_internal.h"
#include "hwcontext_qsv.h"
#include "mem.h"
#include "pixfmt.h"
#include "pixdesc.h"
#include "time.h"
#include "imgutils.h"

#define QSV_VERSION_ATLEAST(MAJOR, MINOR)   \
    (MFX_VERSION_MAJOR > (MAJOR) ||         \
     MFX_VERSION_MAJOR == (MAJOR) && MFX_VERSION_MINOR >= (MINOR))

#define MFX_IMPL_VIA_MASK(impl) (0x0f00 & (impl))

typedef struct QSVDevicePriv {
    AVBufferRef *child_device_ctx;
} QSVDevicePriv;

typedef struct QSVDeviceContext {
    mfxHDL              handle;
    mfxHandleType       handle_type;
    mfxVersion          ver;
    mfxIMPL             impl;

    enum AVHWDeviceType child_device_type;
    enum AVPixelFormat  child_pix_fmt;
} QSVDeviceContext;

typedef struct QSVFramesContext {
    mfxSession session_download;
    atomic_int session_download_init;
    mfxSession session_upload;
    atomic_int session_upload_init;
#if HAVE_PTHREADS
    pthread_mutex_t session_lock;
#endif

    AVBufferRef *child_frames_ref;
    mfxFrameSurface1 *surfaces_internal;
    mfxHDLPair *handle_pairs_internal;
    int             nb_surfaces_used;

    // used in the frame allocator for non-opaque surfaces
    mfxMemId *mem_ids;
    // used in the opaque alloc request for opaque surfaces
    mfxFrameSurface1 **surface_ptrs;

    mfxExtOpaqueSurfaceAlloc opaque_alloc;
    mfxExtBuffer *ext_buffers[1];
    AVFrame realigned_upload_frame;
    AVFrame realigned_download_frame;
} QSVFramesContext;

static const struct {
    enum AVPixelFormat pix_fmt;
    uint32_t           fourcc;
} supported_pixel_formats[] = {
    { AV_PIX_FMT_NV12, MFX_FOURCC_NV12 },
    { AV_PIX_FMT_BGRA, MFX_FOURCC_RGB4 },
    { AV_PIX_FMT_P010, MFX_FOURCC_P010 },
    { AV_PIX_FMT_PAL8, MFX_FOURCC_P8   },
#if CONFIG_VAAPI
    { AV_PIX_FMT_YUYV422,
                       MFX_FOURCC_YUY2 },
#if QSV_VERSION_ATLEAST(1, 27)
    { AV_PIX_FMT_Y210,
                       MFX_FOURCC_Y210 },
#endif
#endif
};

extern int ff_qsv_get_surface_base_handle(mfxFrameSurface1 *surf,
                                          enum AVHWDeviceType base_dev_type,
                                          void **base_handle);

/**
 * Caller needs to allocate enough space for base_handle pointer.
 **/
int ff_qsv_get_surface_base_handle(mfxFrameSurface1 *surf,
                                   enum AVHWDeviceType base_dev_type,
                                   void **base_handle)
{
    mfxHDLPair *handle_pair;
    handle_pair = surf->Data.MemId;
    switch (base_dev_type) {
#if CONFIG_VAAPI
    case AV_HWDEVICE_TYPE_VAAPI:
        base_handle[0] = handle_pair->first;
        return 0;
#endif
#if CONFIG_D3D11VA
    case AV_HWDEVICE_TYPE_D3D11VA:
        base_handle[0] = handle_pair->first;
        base_handle[1] = handle_pair->second;
        return 0;
#endif
#if CONFIG_DXVA2
    case AV_HWDEVICE_TYPE_DXVA2:
        base_handle[0] = handle_pair->first;
        return 0;
#endif
    }
    return AVERROR(EINVAL);
}

static uint32_t qsv_fourcc_from_pix_fmt(enum AVPixelFormat pix_fmt)
{
    int i;
    for (i = 0; i < FF_ARRAY_ELEMS(supported_pixel_formats); i++) {
        if (supported_pixel_formats[i].pix_fmt == pix_fmt)
            return supported_pixel_formats[i].fourcc;
    }
    return 0;
}

#if CONFIG_D3D11VA
static uint32_t qsv_get_d3d11va_bind_flags(int mem_type)
{
    uint32_t bind_flags = 0;

    if ((mem_type & MFX_MEMTYPE_VIDEO_MEMORY_ENCODER_TARGET) && (mem_type & MFX_MEMTYPE_INTERNAL_FRAME))
        bind_flags = D3D11_BIND_DECODER | D3D11_BIND_VIDEO_ENCODER;
    else
        bind_flags = D3D11_BIND_DECODER;

    if ((MFX_MEMTYPE_FROM_VPPOUT & mem_type) || (MFX_MEMTYPE_VIDEO_MEMORY_PROCESSOR_TARGET & mem_type))
        bind_flags = D3D11_BIND_RENDER_TARGET;

    return bind_flags;
}
#endif

static int qsv_fill_border(AVFrame *dst, const AVFrame *src)
{
    const AVPixFmtDescriptor *desc;
    int i, planes_nb = 0;
    if (dst->format != src->format)
        return AVERROR(EINVAL);

    desc = av_pix_fmt_desc_get(dst->format);

    for (i = 0; i < desc->nb_components; i++)
        planes_nb = FFMAX(planes_nb, desc->comp[i].plane + 1);

    for (i = 0; i < planes_nb; i++) {
        int sheight, dheight, y;
        ptrdiff_t swidth = av_image_get_linesize(src->format,
                                                 src->width,
                                                 i);
        ptrdiff_t dwidth = av_image_get_linesize(dst->format,
                                                 dst->width,
                                                 i);
        const AVComponentDescriptor comp = desc->comp[i];
        if (swidth < 0 || dwidth < 0) {
            av_log(NULL, AV_LOG_ERROR, "av_image_get_linesize failed\n");
            return AVERROR(EINVAL);
        }
        sheight = src->height;
        dheight = dst->height;
        if (i) {
            sheight = AV_CEIL_RSHIFT(src->height, desc->log2_chroma_h);
            dheight = AV_CEIL_RSHIFT(dst->height, desc->log2_chroma_h);
        }
        //fill right padding
        for (y = 0; y < sheight; y++) {
            void *line_ptr = dst->data[i] + y*dst->linesize[i] + swidth;
            av_memcpy_backptr(line_ptr,
                           comp.depth > 8 ? 2 : 1,
                           dwidth - swidth);
        }
        //fill bottom padding
        for (y = sheight; y < dheight; y++) {
            memcpy(dst->data[i]+y*dst->linesize[i],
                   dst->data[i]+(sheight-1)*dst->linesize[i],
                   dwidth);
        }
    }
    return 0;
}

static int qsv_device_init(AVHWDeviceContext *ctx)
{
    AVQSVDeviceContext *hwctx = ctx->hwctx;
    QSVDeviceContext       *s = ctx->internal->priv;
    int   hw_handle_supported = 0;
    mfxHandleType handle_type;
    enum AVHWDeviceType device_type;
    enum AVPixelFormat  pix_fmt;
    mfxStatus err;

    err = MFXQueryIMPL(hwctx->session, &s->impl);
    if (err == MFX_ERR_NONE)
        err = MFXQueryVersion(hwctx->session, &s->ver);
    if (err != MFX_ERR_NONE) {
        av_log(ctx, AV_LOG_ERROR, "Error querying the session attributes\n");
        return AVERROR_UNKNOWN;
    }

    if (MFX_IMPL_VIA_VAAPI == MFX_IMPL_VIA_MASK(s->impl)) {
#if CONFIG_VAAPI
        handle_type = MFX_HANDLE_VA_DISPLAY;
        device_type = AV_HWDEVICE_TYPE_VAAPI;
        pix_fmt = AV_PIX_FMT_VAAPI;
        hw_handle_supported = 1;
#endif
    } else if (MFX_IMPL_VIA_D3D11 == MFX_IMPL_VIA_MASK(s->impl)) {
#if CONFIG_D3D11VA
        handle_type = MFX_HANDLE_D3D11_DEVICE;
        device_type = AV_HWDEVICE_TYPE_D3D11VA;
        pix_fmt = AV_PIX_FMT_D3D11;
        hw_handle_supported = 1;
#endif
    } else if (MFX_IMPL_VIA_D3D9 == MFX_IMPL_VIA_MASK(s->impl)) {
#if CONFIG_DXVA2
        handle_type = MFX_HANDLE_D3D9_DEVICE_MANAGER;
        device_type = AV_HWDEVICE_TYPE_DXVA2;
        pix_fmt = AV_PIX_FMT_DXVA2_VLD;
        hw_handle_supported = 1;
#endif
    }

    if (hw_handle_supported) {
        err = MFXVideoCORE_GetHandle(hwctx->session, handle_type, &s->handle);
        if (err == MFX_ERR_NONE) {
            s->handle_type       = handle_type;
            s->child_device_type = device_type;
            s->child_pix_fmt     = pix_fmt;
        }
    }
    if (!s->handle) {
        av_log(ctx, AV_LOG_VERBOSE, "No supported hw handle could be retrieved "
               "from the session\n");
    }
    return 0;
}

static void qsv_frames_uninit(AVHWFramesContext *ctx)
{
    QSVFramesContext *s = ctx->internal->priv;

    if (s->session_download) {
        MFXVideoVPP_Close(s->session_download);
        MFXClose(s->session_download);
    }
    s->session_download = NULL;
    s->session_download_init = 0;

    if (s->session_upload) {
        MFXVideoVPP_Close(s->session_upload);
        MFXClose(s->session_upload);
    }
    s->session_upload = NULL;
    s->session_upload_init = 0;

#if HAVE_PTHREADS
    pthread_mutex_destroy(&s->session_lock);
#endif

    av_freep(&s->mem_ids);
    av_freep(&s->surface_ptrs);
    av_freep(&s->surfaces_internal);
    av_freep(&s->handle_pairs_internal);
    av_frame_unref(&s->realigned_upload_frame);
    av_frame_unref(&s->realigned_download_frame);
    av_buffer_unref(&s->child_frames_ref);
}

static void qsv_pool_release_dummy(void *opaque, uint8_t *data)
{
}

static AVBufferRef *qsv_pool_alloc(void *opaque, size_t size)
{
    AVHWFramesContext    *ctx = (AVHWFramesContext*)opaque;
    QSVFramesContext       *s = ctx->internal->priv;
    AVQSVFramesContext *hwctx = ctx->hwctx;

    if (s->nb_surfaces_used < hwctx->nb_surfaces) {
        s->nb_surfaces_used++;
        return av_buffer_create((uint8_t*)(s->surfaces_internal + s->nb_surfaces_used - 1),
                                sizeof(*hwctx->surfaces), qsv_pool_release_dummy, NULL, 0);
    }

    return NULL;
}

static int qsv_init_child_ctx(AVHWFramesContext *ctx)
{
    AVQSVFramesContext     *hwctx = ctx->hwctx;
    QSVFramesContext           *s = ctx->internal->priv;
    QSVDeviceContext *device_priv = ctx->device_ctx->internal->priv;

    AVBufferRef *child_device_ref = NULL;
    AVBufferRef *child_frames_ref = NULL;

    AVHWDeviceContext *child_device_ctx;
    AVHWFramesContext *child_frames_ctx;

    int i, ret = 0;

    if (!device_priv->handle) {
        av_log(ctx, AV_LOG_ERROR,
               "Cannot create a non-opaque internal surface pool without "
               "a hardware handle\n");
        return AVERROR(EINVAL);
    }

    child_device_ref = av_hwdevice_ctx_alloc(device_priv->child_device_type);
    if (!child_device_ref)
        return AVERROR(ENOMEM);
    child_device_ctx   = (AVHWDeviceContext*)child_device_ref->data;

#if CONFIG_VAAPI
    if (child_device_ctx->type == AV_HWDEVICE_TYPE_VAAPI) {
        AVVAAPIDeviceContext *child_device_hwctx = child_device_ctx->hwctx;
        child_device_hwctx->display = (VADisplay)device_priv->handle;
    }
#endif
#if CONFIG_D3D11VA
    if (child_device_ctx->type == AV_HWDEVICE_TYPE_D3D11VA) {
        AVD3D11VADeviceContext *child_device_hwctx = child_device_ctx->hwctx;
        ID3D11Device_AddRef((ID3D11Device*)device_priv->handle);
        child_device_hwctx->device = (ID3D11Device*)device_priv->handle;
    }
#endif
#if CONFIG_DXVA2
    if (child_device_ctx->type == AV_HWDEVICE_TYPE_DXVA2) {
        AVDXVA2DeviceContext *child_device_hwctx = child_device_ctx->hwctx;
        child_device_hwctx->devmgr = (IDirect3DDeviceManager9*)device_priv->handle;
    }
#endif

    ret = av_hwdevice_ctx_init(child_device_ref);
    if (ret < 0) {
        av_log(ctx, AV_LOG_ERROR, "Error initializing a child device context\n");
        goto fail;
    }

    child_frames_ref = av_hwframe_ctx_alloc(child_device_ref);
    if (!child_frames_ref) {
        ret = AVERROR(ENOMEM);
        goto fail;
    }
    child_frames_ctx = (AVHWFramesContext*)child_frames_ref->data;

    child_frames_ctx->format            = device_priv->child_pix_fmt;
    child_frames_ctx->sw_format         = ctx->sw_format;
    child_frames_ctx->initial_pool_size = ctx->initial_pool_size;
    child_frames_ctx->width             = FFALIGN(ctx->width, 16);
    child_frames_ctx->height            = FFALIGN(ctx->height, 16);

#if CONFIG_D3D11VA
    if (child_device_ctx->type == AV_HWDEVICE_TYPE_D3D11VA) {
        AVD3D11VAFramesContext *child_frames_hwctx = child_frames_ctx->hwctx;
        if (hwctx->frame_type == 0)
            hwctx->frame_type = MFX_MEMTYPE_VIDEO_MEMORY_PROCESSOR_TARGET;
        if (hwctx->frame_type & MFX_MEMTYPE_SHARED_RESOURCE)
            child_frames_hwctx->MiscFlags = D3D11_RESOURCE_MISC_SHARED;
        child_frames_hwctx->BindFlags = qsv_get_d3d11va_bind_flags(hwctx->frame_type);
    }
#endif
#if CONFIG_DXVA2
    if (child_device_ctx->type == AV_HWDEVICE_TYPE_DXVA2) {
        AVDXVA2FramesContext *child_frames_hwctx = child_frames_ctx->hwctx;
        if (hwctx->frame_type & MFX_MEMTYPE_VIDEO_MEMORY_PROCESSOR_TARGET)
            child_frames_hwctx->surface_type = DXVA2_VideoProcessorRenderTarget;
        else
            child_frames_hwctx->surface_type = DXVA2_VideoDecoderRenderTarget;
    }
#endif

    ret = av_hwframe_ctx_init(child_frames_ref);
    if (ret < 0) {
        av_log(ctx, AV_LOG_ERROR, "Error initializing a child frames context\n");
        goto fail;
    }

#if CONFIG_VAAPI
    if (child_device_ctx->type == AV_HWDEVICE_TYPE_VAAPI) {
        AVVAAPIFramesContext *child_frames_hwctx = child_frames_ctx->hwctx;
        for (i = 0; i < ctx->initial_pool_size; i++) {
            s->handle_pairs_internal[i].first = child_frames_hwctx->surface_ids + i;
            s->handle_pairs_internal[i].second = (mfxMemId)MFX_INFINITE;
            s->surfaces_internal[i].Data.MemId = (mfxMemId)&s->handle_pairs_internal[i];
        }
        hwctx->frame_type = MFX_MEMTYPE_VIDEO_MEMORY_DECODER_TARGET;
    }
#endif
#if CONFIG_D3D11VA
    if (child_device_ctx->type == AV_HWDEVICE_TYPE_D3D11VA) {
        AVD3D11VAFramesContext *child_frames_hwctx = child_frames_ctx->hwctx;
        for (i = 0; i < ctx->initial_pool_size; i++) {
            s->handle_pairs_internal[i].first = (mfxMemId)child_frames_hwctx->texture_infos[i].texture;
            if(child_frames_hwctx->BindFlags & D3D11_BIND_RENDER_TARGET) {
                s->handle_pairs_internal[i].second = (mfxMemId)MFX_INFINITE;
            } else {
                s->handle_pairs_internal[i].second = (mfxMemId)child_frames_hwctx->texture_infos[i].index;
            }
            s->surfaces_internal[i].Data.MemId = (mfxMemId)&s->handle_pairs_internal[i];
        }
        if (child_frames_hwctx->BindFlags & D3D11_BIND_RENDER_TARGET) {
            hwctx->frame_type |= MFX_MEMTYPE_VIDEO_MEMORY_PROCESSOR_TARGET;
        } else {
            hwctx->frame_type |= MFX_MEMTYPE_VIDEO_MEMORY_DECODER_TARGET;
        }
    }
#endif
#if CONFIG_DXVA2
    if (child_device_ctx->type == AV_HWDEVICE_TYPE_DXVA2) {
        AVDXVA2FramesContext *child_frames_hwctx = child_frames_ctx->hwctx;
        for (i = 0; i < ctx->initial_pool_size; i++) {
            s->handle_pairs_internal[i].first = (mfxMemId)child_frames_hwctx->surfaces[i];
            s->handle_pairs_internal[i].second = (mfxMemId)MFX_INFINITE;
            s->surfaces_internal[i].Data.MemId = (mfxMemId)&s->handle_pairs_internal[i];
        }
        if (child_frames_hwctx->surface_type == DXVA2_VideoProcessorRenderTarget)
            hwctx->frame_type = MFX_MEMTYPE_VIDEO_MEMORY_PROCESSOR_TARGET;
        else
            hwctx->frame_type = MFX_MEMTYPE_VIDEO_MEMORY_DECODER_TARGET;
    }
#endif

    s->child_frames_ref       = child_frames_ref;
    child_frames_ref          = NULL;

fail:
    av_buffer_unref(&child_device_ref);
    av_buffer_unref(&child_frames_ref);
    return ret;
}

static int qsv_init_surface(AVHWFramesContext *ctx, mfxFrameSurface1 *surf)
{
    const AVPixFmtDescriptor *desc;
    uint32_t fourcc;

    desc = av_pix_fmt_desc_get(ctx->sw_format);
    if (!desc)
        return AVERROR(EINVAL);

    fourcc = qsv_fourcc_from_pix_fmt(ctx->sw_format);
    if (!fourcc)
        return AVERROR(EINVAL);

    surf->Info.BitDepthLuma   = desc->comp[0].depth;
    surf->Info.BitDepthChroma = desc->comp[0].depth;
    surf->Info.Shift          = desc->comp[0].depth > 8;

    if (desc->log2_chroma_w && desc->log2_chroma_h)
        surf->Info.ChromaFormat   = MFX_CHROMAFORMAT_YUV420;
    else if (desc->log2_chroma_w)
        surf->Info.ChromaFormat   = MFX_CHROMAFORMAT_YUV422;
    else
        surf->Info.ChromaFormat   = MFX_CHROMAFORMAT_YUV444;

    surf->Info.FourCC         = fourcc;
    surf->Info.Width          = FFALIGN(ctx->width, 16);
    surf->Info.CropW          = ctx->width;
    surf->Info.Height         = FFALIGN(ctx->height, 16);
    surf->Info.CropH          = ctx->height;
    surf->Info.FrameRateExtN  = 25;
    surf->Info.FrameRateExtD  = 1;
    surf->Info.PicStruct      = MFX_PICSTRUCT_PROGRESSIVE;

    return 0;
}

static int qsv_init_pool(AVHWFramesContext *ctx, uint32_t fourcc)
{
    QSVFramesContext              *s = ctx->internal->priv;
    AVQSVFramesContext *frames_hwctx = ctx->hwctx;

    int i, ret = 0;

    if (ctx->initial_pool_size <= 0) {
        av_log(ctx, AV_LOG_ERROR, "QSV requires a fixed frame pool size\n");
        return AVERROR(EINVAL);
    }

    s->handle_pairs_internal = av_calloc(ctx->initial_pool_size,
                                         sizeof(*s->handle_pairs_internal));
    if (!s->handle_pairs_internal)
        return AVERROR(ENOMEM);

    s->surfaces_internal = av_calloc(ctx->initial_pool_size,
                                     sizeof(*s->surfaces_internal));
    if (!s->surfaces_internal)
        return AVERROR(ENOMEM);

    for (i = 0; i < ctx->initial_pool_size; i++) {
        ret = qsv_init_surface(ctx, &s->surfaces_internal[i]);
        if (ret < 0)
            return ret;
    }

    if (!(frames_hwctx->frame_type & MFX_MEMTYPE_OPAQUE_FRAME)) {
        ret = qsv_init_child_ctx(ctx);
        if (ret < 0)
            return ret;
    }

    ctx->internal->pool_internal = av_buffer_pool_init2(sizeof(mfxFrameSurface1),
                                                        ctx, qsv_pool_alloc, NULL);
    if (!ctx->internal->pool_internal)
        return AVERROR(ENOMEM);

    frames_hwctx->surfaces    = s->surfaces_internal;
    frames_hwctx->nb_surfaces = ctx->initial_pool_size;

    return 0;
}

static mfxStatus frame_alloc(mfxHDL pthis, mfxFrameAllocRequest *req,
                             mfxFrameAllocResponse *resp)
{
    AVHWFramesContext    *ctx = pthis;
    QSVFramesContext       *s = ctx->internal->priv;
    AVQSVFramesContext *hwctx = ctx->hwctx;
    mfxFrameInfo *i  = &req->Info;
    mfxFrameInfo *i1 = &hwctx->surfaces[0].Info;

    if (!(req->Type & MFX_MEMTYPE_VIDEO_MEMORY_PROCESSOR_TARGET) ||
        !(req->Type & (MFX_MEMTYPE_FROM_VPPIN | MFX_MEMTYPE_FROM_VPPOUT)) ||
        !(req->Type & MFX_MEMTYPE_EXTERNAL_FRAME))
        return MFX_ERR_UNSUPPORTED;
    if (i->Width  > i1->Width || i->Height > i1->Height ||
        i->FourCC != i1->FourCC || i->ChromaFormat != i1->ChromaFormat) {
        av_log(ctx, AV_LOG_ERROR, "Mismatching surface properties in an "
               "allocation request: %dx%d %d %d vs %dx%d %d %d\n",
               i->Width,  i->Height,  i->FourCC,  i->ChromaFormat,
               i1->Width, i1->Height, i1->FourCC, i1->ChromaFormat);
        return MFX_ERR_UNSUPPORTED;
    }

    resp->mids           = s->mem_ids;
    resp->NumFrameActual = hwctx->nb_surfaces;

    return MFX_ERR_NONE;
}

static mfxStatus frame_free(mfxHDL pthis, mfxFrameAllocResponse *resp)
{
    return MFX_ERR_NONE;
}

static mfxStatus frame_lock(mfxHDL pthis, mfxMemId mid, mfxFrameData *ptr)
{
    return MFX_ERR_UNSUPPORTED;
}

static mfxStatus frame_unlock(mfxHDL pthis, mfxMemId mid, mfxFrameData *ptr)
{
    return MFX_ERR_UNSUPPORTED;
}

static mfxStatus frame_get_hdl(mfxHDL pthis, mfxMemId mid, mfxHDL *hdl)
{
    mfxHDLPair *pair_dst = (mfxHDLPair*)hdl;
    mfxHDLPair *pair_src = (mfxHDLPair*)mid;

    pair_dst->first = pair_src->first;

    if (pair_src->second != (mfxMemId)MFX_INFINITE)
        pair_dst->second = pair_src->second;
    return MFX_ERR_NONE;
}

static int qsv_init_internal_session(AVHWFramesContext *ctx,
                                     mfxSession *session, int upload)
{
    QSVFramesContext              *s = ctx->internal->priv;
    AVQSVFramesContext *frames_hwctx = ctx->hwctx;
    QSVDeviceContext   *device_priv  = ctx->device_ctx->internal->priv;
    int opaque = !!(frames_hwctx->frame_type & MFX_MEMTYPE_OPAQUE_FRAME);

    mfxFrameAllocator frame_allocator = {
        .pthis  = ctx,
        .Alloc  = frame_alloc,
        .Lock   = frame_lock,
        .Unlock = frame_unlock,
        .GetHDL = frame_get_hdl,
        .Free   = frame_free,
    };

    mfxVideoParam par;
    mfxStatus err;

    err = MFXInit(device_priv->impl, &device_priv->ver, session);
    if (err != MFX_ERR_NONE) {
        av_log(ctx, AV_LOG_ERROR, "Error initializing an internal session\n");
        return AVERROR_UNKNOWN;
    }

    if (device_priv->handle) {
        err = MFXVideoCORE_SetHandle(*session, device_priv->handle_type,
                                     device_priv->handle);
        if (err != MFX_ERR_NONE)
            return AVERROR_UNKNOWN;
    }

    if (!opaque) {
        err = MFXVideoCORE_SetFrameAllocator(*session, &frame_allocator);
        if (err != MFX_ERR_NONE)
            return AVERROR_UNKNOWN;
    }

    memset(&par, 0, sizeof(par));

    if (opaque) {
        par.ExtParam    = s->ext_buffers;
        par.NumExtParam = FF_ARRAY_ELEMS(s->ext_buffers);
        par.IOPattern   = upload ? MFX_IOPATTERN_OUT_OPAQUE_MEMORY :
                                   MFX_IOPATTERN_IN_OPAQUE_MEMORY;
    } else {
        par.IOPattern = upload ? MFX_IOPATTERN_OUT_VIDEO_MEMORY :
                                 MFX_IOPATTERN_IN_VIDEO_MEMORY;
    }

    par.IOPattern |= upload ? MFX_IOPATTERN_IN_SYSTEM_MEMORY :
                              MFX_IOPATTERN_OUT_SYSTEM_MEMORY;
    par.AsyncDepth = 1;

    par.vpp.In = frames_hwctx->surfaces[0].Info;

    /* Apparently VPP requires the frame rate to be set to some value, otherwise
     * init will fail (probably for the framerate conversion filter). Since we
     * are only doing data upload/download here, we just invent an arbitrary
     * value */
    par.vpp.In.FrameRateExtN = 25;
    par.vpp.In.FrameRateExtD = 1;
    par.vpp.Out = par.vpp.In;

    err = MFXVideoVPP_Init(*session, &par);
    if (err != MFX_ERR_NONE) {
        av_log(ctx, AV_LOG_VERBOSE, "Error opening the internal VPP session."
               "Surface upload/download will not be possible\n");
        MFXClose(*session);
        *session = NULL;
    }

    return 0;
}

static int qsv_frames_init(AVHWFramesContext *ctx)
{
    QSVFramesContext              *s = ctx->internal->priv;
    AVQSVFramesContext *frames_hwctx = ctx->hwctx;

    int opaque = !!(frames_hwctx->frame_type & MFX_MEMTYPE_OPAQUE_FRAME);

    uint32_t fourcc;
    int i, ret;

    fourcc = qsv_fourcc_from_pix_fmt(ctx->sw_format);
    if (!fourcc) {
        av_log(ctx, AV_LOG_ERROR, "Unsupported pixel format\n");
        return AVERROR(ENOSYS);
    }

    if (!ctx->pool) {
        ret = qsv_init_pool(ctx, fourcc);
        if (ret < 0) {
            av_log(ctx, AV_LOG_ERROR, "Error creating an internal frame pool\n");
            return ret;
        }
    }

    if (opaque) {
        s->surface_ptrs = av_calloc(frames_hwctx->nb_surfaces,
                                    sizeof(*s->surface_ptrs));
        if (!s->surface_ptrs)
            return AVERROR(ENOMEM);

        for (i = 0; i < frames_hwctx->nb_surfaces; i++)
            s->surface_ptrs[i] = frames_hwctx->surfaces + i;

        s->opaque_alloc.In.Surfaces   = s->surface_ptrs;
        s->opaque_alloc.In.NumSurface = frames_hwctx->nb_surfaces;
        s->opaque_alloc.In.Type       = frames_hwctx->frame_type;

        s->opaque_alloc.Out = s->opaque_alloc.In;

        s->opaque_alloc.Header.BufferId = MFX_EXTBUFF_OPAQUE_SURFACE_ALLOCATION;
        s->opaque_alloc.Header.BufferSz = sizeof(s->opaque_alloc);

        s->ext_buffers[0] = (mfxExtBuffer*)&s->opaque_alloc;
    } else {
        s->mem_ids = av_calloc(frames_hwctx->nb_surfaces, sizeof(*s->mem_ids));
        if (!s->mem_ids)
            return AVERROR(ENOMEM);

        for (i = 0; i < frames_hwctx->nb_surfaces; i++)
            s->mem_ids[i] = frames_hwctx->surfaces[i].Data.MemId;
    }

    s->session_download = NULL;
    s->session_upload   = NULL;

    s->session_download_init = 0;
    s->session_upload_init   = 0;

#if HAVE_PTHREADS
    pthread_mutex_init(&s->session_lock, NULL);
#endif

    return 0;
}

static int qsv_get_buffer(AVHWFramesContext *ctx, AVFrame *frame)
{
    frame->buf[0] = av_buffer_pool_get(ctx->pool);
    if (!frame->buf[0])
        return AVERROR(ENOMEM);

    frame->data[3] = frame->buf[0]->data;
    frame->format  = AV_PIX_FMT_QSV;
    frame->width   = ctx->width;
    frame->height  = ctx->height;

    return 0;
}

static int qsv_transfer_get_formats(AVHWFramesContext *ctx,
                                    enum AVHWFrameTransferDirection dir,
                                    enum AVPixelFormat **formats)
{
    enum AVPixelFormat *fmts;

    fmts = av_malloc_array(2, sizeof(*fmts));
    if (!fmts)
        return AVERROR(ENOMEM);

    fmts[0] = ctx->sw_format;
    fmts[1] = AV_PIX_FMT_NONE;

    *formats = fmts;

    return 0;
}

static int qsv_frames_derive_from(AVHWFramesContext *dst_ctx,
                                  AVHWFramesContext *src_ctx, int flags)
{
    AVQSVFramesContext *src_hwctx = src_ctx->hwctx;
    int i;

    switch (dst_ctx->device_ctx->type) {
#if CONFIG_VAAPI
    case AV_HWDEVICE_TYPE_VAAPI:
        {
            AVVAAPIFramesContext *dst_hwctx = dst_ctx->hwctx;
            dst_hwctx->surface_ids = av_calloc(src_hwctx->nb_surfaces,
                                               sizeof(*dst_hwctx->surface_ids));
            if (!dst_hwctx->surface_ids)
                return AVERROR(ENOMEM);
            for (i = 0; i < src_hwctx->nb_surfaces; i++) {
                mfxHDLPair *pair = (mfxHDLPair*)src_hwctx->surfaces[i].Data.MemId;
                dst_hwctx->surface_ids[i] = *(VASurfaceID*)pair->first;
            }
            dst_hwctx->nb_surfaces = src_hwctx->nb_surfaces;
        }
        break;
#endif
#if CONFIG_D3D11VA
    case AV_HWDEVICE_TYPE_D3D11VA:
        {
            D3D11_TEXTURE2D_DESC texDesc;
            dst_ctx->initial_pool_size = src_ctx->initial_pool_size;
            AVD3D11VAFramesContext *dst_hwctx = dst_ctx->hwctx;
            dst_hwctx->texture_infos = av_calloc(src_hwctx->nb_surfaces,
                                                 sizeof(*dst_hwctx->texture_infos));
            if (!dst_hwctx->texture_infos)
                return AVERROR(ENOMEM);
            if (src_hwctx->frame_type & MFX_MEMTYPE_SHARED_RESOURCE)
                dst_hwctx->MiscFlags = D3D11_RESOURCE_MISC_SHARED;
            for (i = 0; i < src_hwctx->nb_surfaces; i++) {
                mfxHDLPair *pair = (mfxHDLPair*)src_hwctx->surfaces[i].Data.MemId;
                dst_hwctx->texture_infos[i].texture = (ID3D11Texture2D*)pair->first;
                dst_hwctx->texture_infos[i].index = pair->second == (mfxMemId)MFX_INFINITE ? (intptr_t)0 : (intptr_t)pair->second;
            }
            ID3D11Texture2D_GetDesc(dst_hwctx->texture_infos[0].texture, &texDesc);
            dst_hwctx->BindFlags = texDesc.BindFlags;
        }
        break;
#endif
#if CONFIG_DXVA2
    case AV_HWDEVICE_TYPE_DXVA2:
        {
            AVDXVA2FramesContext *dst_hwctx = dst_ctx->hwctx;
            dst_hwctx->surfaces = av_calloc(src_hwctx->nb_surfaces,
                                            sizeof(*dst_hwctx->surfaces));
            if (!dst_hwctx->surfaces)
                return AVERROR(ENOMEM);
            for (i = 0; i < src_hwctx->nb_surfaces; i++) {
                mfxHDLPair *pair = (mfxHDLPair*)src_hwctx->surfaces[i].Data.MemId;
                dst_hwctx->surfaces[i] = (IDirect3DSurface9*)pair->first;
            }
            dst_hwctx->nb_surfaces = src_hwctx->nb_surfaces;
            if (src_hwctx->frame_type == MFX_MEMTYPE_VIDEO_MEMORY_DECODER_TARGET)
                dst_hwctx->surface_type = DXVA2_VideoDecoderRenderTarget;
            else
                dst_hwctx->surface_type = DXVA2_VideoProcessorRenderTarget;
        }
        break;
#endif
    default:
        return AVERROR(ENOSYS);
    }

    return 0;
}

static int qsv_map_from(AVHWFramesContext *ctx,
                        AVFrame *dst, const AVFrame *src, int flags)
{
    QSVFramesContext *s = ctx->internal->priv;
    mfxFrameSurface1 *surf = (mfxFrameSurface1*)src->data[3];
    AVHWFramesContext *child_frames_ctx;
    const AVPixFmtDescriptor *desc;
    uint8_t *child_data;
    AVFrame *dummy;
    int ret = 0;

    if (!s->child_frames_ref)
        return AVERROR(ENOSYS);
    child_frames_ctx = (AVHWFramesContext*)s->child_frames_ref->data;

    switch (child_frames_ctx->device_ctx->type) {
#if CONFIG_VAAPI
    case AV_HWDEVICE_TYPE_VAAPI:
    {
        mfxHDLPair *pair = (mfxHDLPair*)surf->Data.MemId;
        /* pair->first is *VASurfaceID while data[3] in vaapi frame is VASurfaceID, so
         * we need this casting for vaapi.
         * Add intptr_t to force cast from VASurfaceID(uint) type to pointer(long) type
         * to avoid compile warning */
        child_data = (uint8_t*)(intptr_t)*(VASurfaceID*)pair->first;
        break;
    }
#endif
#if CONFIG_D3D11VA
    case AV_HWDEVICE_TYPE_D3D11VA:
    {
        mfxHDLPair *pair = (mfxHDLPair*)surf->Data.MemId;
        child_data = pair->first;
        break;
    }
#endif
#if CONFIG_DXVA2
    case AV_HWDEVICE_TYPE_DXVA2:
    {
        mfxHDLPair *pair = (mfxHDLPair*)surf->Data.MemId;
        child_data = pair->first;
        break;
    }
#endif
    default:
        return AVERROR(ENOSYS);
    }

    if (dst->format == child_frames_ctx->format) {
        ret = ff_hwframe_map_create(s->child_frames_ref,
                                    dst, src, NULL, NULL);
        if (ret < 0)
            return ret;

        dst->width   = src->width;
        dst->height  = src->height;

       if (child_frames_ctx->device_ctx->type == AV_HWDEVICE_TYPE_D3D11VA) {
            mfxHDLPair *pair = (mfxHDLPair*)surf->Data.MemId;
            dst->data[0] = pair->first;
            dst->data[1] = pair->second;
        } else {
            dst->data[3] = child_data;
        }

        return 0;
    }

    desc = av_pix_fmt_desc_get(dst->format);
    if (desc && desc->flags & AV_PIX_FMT_FLAG_HWACCEL) {
        // This only supports mapping to software.
        return AVERROR(ENOSYS);
    }

    dummy = av_frame_alloc();
    if (!dummy)
        return AVERROR(ENOMEM);

    dummy->buf[0]        = av_buffer_ref(src->buf[0]);
    dummy->hw_frames_ctx = av_buffer_ref(s->child_frames_ref);
    if (!dummy->buf[0] || !dummy->hw_frames_ctx)
        goto fail;

    dummy->format        = child_frames_ctx->format;
    dummy->width         = src->width;
    dummy->height        = src->height;

    if (child_frames_ctx->device_ctx->type == AV_HWDEVICE_TYPE_D3D11VA) {
        mfxHDLPair *pair = (mfxHDLPair*)surf->Data.MemId;
        dummy->data[0] = pair->first;
        dummy->data[1] = pair->second;
    } else {
        dummy->data[3] = child_data;
    }

    ret = av_hwframe_map(dst, dummy, flags);

fail:
    av_frame_free(&dummy);

    return ret;
}

static int qsv_transfer_data_child(AVHWFramesContext *ctx, AVFrame *dst,
                                   const AVFrame *src)
{
    QSVFramesContext *s = ctx->internal->priv;
    AVHWFramesContext *child_frames_ctx = (AVHWFramesContext*)s->child_frames_ref->data;
    int download = !!src->hw_frames_ctx;
    mfxFrameSurface1 *surf = (mfxFrameSurface1*)(download ? src->data[3] : dst->data[3]);

    AVFrame *dummy;
    int ret;

    dummy = av_frame_alloc();
    if (!dummy)
        return AVERROR(ENOMEM);

    dummy->format        = child_frames_ctx->format;
    dummy->width         = src->width;
    dummy->height        = src->height;
    dummy->buf[0]        = download ? src->buf[0] : dst->buf[0];
    dummy->data[3]       = surf->Data.MemId;
    dummy->hw_frames_ctx = s->child_frames_ref;

    ret = download ? av_hwframe_transfer_data(dst, dummy, 0) :
                     av_hwframe_transfer_data(dummy, src, 0);

    dummy->buf[0]        = NULL;
    dummy->data[3]       = NULL;
    dummy->hw_frames_ctx = NULL;

    av_frame_free(&dummy);

    return ret;
}

static int map_frame_to_surface(const AVFrame *frame, mfxFrameSurface1 *surface)
{
    switch (frame->format) {
    case AV_PIX_FMT_NV12:
    case AV_PIX_FMT_P010:
        surface->Data.Y  = frame->data[0];
        surface->Data.UV = frame->data[1];
        break;

    case AV_PIX_FMT_YUV420P:
        surface->Data.Y = frame->data[0];
        surface->Data.U = frame->data[1];
        surface->Data.V = frame->data[2];
        break;

    case AV_PIX_FMT_BGRA:
        surface->Data.B = frame->data[0];
        surface->Data.G = frame->data[0] + 1;
        surface->Data.R = frame->data[0] + 2;
        surface->Data.A = frame->data[0] + 3;
        break;
#if CONFIG_VAAPI
    case AV_PIX_FMT_YUYV422:
        surface->Data.Y = frame->data[0];
        surface->Data.U = frame->data[0] + 1;
        surface->Data.V = frame->data[0] + 3;
        break;

    case AV_PIX_FMT_Y210:
        surface->Data.Y16 = (mfxU16 *)frame->data[0];
        surface->Data.U16 = (mfxU16 *)frame->data[0] + 1;
        surface->Data.V16 = (mfxU16 *)frame->data[0] + 3;
        break;
#endif
    default:
        return MFX_ERR_UNSUPPORTED;
    }
    surface->Data.Pitch     = frame->linesize[0];
    surface->Data.TimeStamp = frame->pts;

    return 0;
}

static int qsv_internal_session_check_init(AVHWFramesContext *ctx, int upload)
{
    QSVFramesContext *s = ctx->internal->priv;
    atomic_int *inited  = upload ? &s->session_upload_init : &s->session_download_init;
    mfxSession *session = upload ? &s->session_upload      : &s->session_download;
    int ret = 0;

    if (atomic_load(inited))
        return 0;

#if HAVE_PTHREADS
    pthread_mutex_lock(&s->session_lock);
#endif

    if (!atomic_load(inited)) {
        ret = qsv_init_internal_session(ctx, session, upload);
        atomic_store(inited, 1);
    }

#if HAVE_PTHREADS
    pthread_mutex_unlock(&s->session_lock);
#endif

    return ret;
}

static int qsv_transfer_data_from(AVHWFramesContext *ctx, AVFrame *dst,
                                  const AVFrame *src)
{
    QSVFramesContext  *s = ctx->internal->priv;
    mfxFrameSurface1 out = {{ 0 }};
    mfxFrameSurface1 *in = (mfxFrameSurface1*)src->data[3];

    mfxSyncPoint sync = NULL;
    mfxStatus err;
    int ret = 0;
    /* download to temp frame if the output is not padded as libmfx requires */
    AVFrame *tmp_frame = &s->realigned_download_frame;
    AVFrame *dst_frame;
    int realigned = 0;

    ret = qsv_internal_session_check_init(ctx, 0);
    if (ret < 0)
        return ret;

    /* According to MSDK spec for mfxframeinfo, "Width must be a multiple of 16.
     * Height must be a multiple of 16 for progressive frame sequence and a
     * multiple of 32 otherwise.", so allign all frames to 16 before downloading. */
    if (dst->height & 15 || dst->linesize[0] & 15) {
        realigned = 1;
        if (tmp_frame->format != dst->format ||
            tmp_frame->width  != FFALIGN(dst->linesize[0], 16) ||
            tmp_frame->height != FFALIGN(dst->height, 16)) {
            av_frame_unref(tmp_frame);

            tmp_frame->format = dst->format;
            tmp_frame->width  = FFALIGN(dst->linesize[0], 16);
            tmp_frame->height = FFALIGN(dst->height, 16);
            ret = av_frame_get_buffer(tmp_frame, 0);
            if (ret < 0)
                return ret;
        }
    }

    dst_frame = realigned ? tmp_frame : dst;

    if (!s->session_download) {
        if (s->child_frames_ref)
            return qsv_transfer_data_child(ctx, dst_frame, src);

        av_log(ctx, AV_LOG_ERROR, "Surface download not possible\n");
        return AVERROR(ENOSYS);
    }

    out.Info = in->Info;
    map_frame_to_surface(dst_frame, &out);

    do {
        err = MFXVideoVPP_RunFrameVPPAsync(s->session_download, in, &out, NULL, &sync);
        if (err == MFX_WRN_DEVICE_BUSY)
            av_usleep(1);
    } while (err == MFX_WRN_DEVICE_BUSY);

    if (err < 0 || !sync) {
        av_log(ctx, AV_LOG_ERROR, "Error downloading the surface\n");
        return AVERROR_UNKNOWN;
    }

    do {
        err = MFXVideoCORE_SyncOperation(s->session_download, sync, 1000);
    } while (err == MFX_WRN_IN_EXECUTION);
    if (err < 0) {
        av_log(ctx, AV_LOG_ERROR, "Error synchronizing the operation: %d\n", err);
        return AVERROR_UNKNOWN;
    }

    if (realigned) {
        tmp_frame->width  = dst->width;
        tmp_frame->height = dst->height;
        ret = av_frame_copy(dst, tmp_frame);
        tmp_frame->width  = FFALIGN(dst->linesize[0], 16);
        tmp_frame->height = FFALIGN(dst->height, 16);
        if (ret < 0)
            return ret;
    }

    return 0;
}

static int qsv_transfer_data_to(AVHWFramesContext *ctx, AVFrame *dst,
                                const AVFrame *src)
{
    QSVFramesContext   *s = ctx->internal->priv;
    mfxFrameSurface1   in = {{ 0 }};
    mfxFrameSurface1 *out = (mfxFrameSurface1*)dst->data[3];
    mfxFrameInfo tmp_info;

    mfxSyncPoint sync = NULL;
    mfxStatus err;
    int ret = 0;
    /* make a copy if the input is not padded as libmfx requires */
    AVFrame *tmp_frame = &s->realigned_upload_frame;
    const AVFrame *src_frame;
    int realigned = 0;

    ret = qsv_internal_session_check_init(ctx, 1);
    if (ret < 0)
        return ret;

    /* According to MSDK spec for mfxframeinfo, "Width must be a multiple of 16.
     * Height must be a multiple of 16 for progressive frame sequence and a
     * multiple of 32 otherwise.", so allign all frames to 16 before uploading. */
    if (src->height & 15 || src->linesize[0] & 15) {
        realigned = 1;
        if (tmp_frame->format != src->format ||
            tmp_frame->width  != FFALIGN(src->width, 16) ||
            tmp_frame->height != FFALIGN(src->height, 16)) {
            av_frame_unref(tmp_frame);

            tmp_frame->format = src->format;
            tmp_frame->width  = FFALIGN(src->width, 16);
            tmp_frame->height = FFALIGN(src->height, 16);
            ret = av_frame_get_buffer(tmp_frame, 0);
            if (ret < 0)
                return ret;
        }
        ret = av_frame_copy(tmp_frame, src);
        if (ret < 0) {
            av_frame_unref(tmp_frame);
            return ret;
        }
        ret = qsv_fill_border(tmp_frame, src);
        if (ret < 0) {
            av_frame_unref(tmp_frame);
            return ret;
        }

        tmp_info = out->Info;
        out->Info.CropW = FFMIN(out->Info.Width,  tmp_frame->width);
        out->Info.CropH = FFMIN(out->Info.Height, tmp_frame->height);
    }

    src_frame = realigned ? tmp_frame : src;

    if (!s->session_upload) {
        if (s->child_frames_ref)
            return qsv_transfer_data_child(ctx, dst, src_frame);

        av_log(ctx, AV_LOG_ERROR, "Surface upload not possible\n");
        return AVERROR(ENOSYS);
    }

    in.Info = out->Info;
    map_frame_to_surface(src_frame, &in);

    do {
        err = MFXVideoVPP_RunFrameVPPAsync(s->session_upload, &in, out, NULL, &sync);
        if (err == MFX_WRN_DEVICE_BUSY)
            av_usleep(1);
    } while (err == MFX_WRN_DEVICE_BUSY);

    if (err < 0 || !sync) {
        av_log(ctx, AV_LOG_ERROR, "Error uploading the surface\n");
        return AVERROR_UNKNOWN;
    }

    do {
        err = MFXVideoCORE_SyncOperation(s->session_upload, sync, 1000);
    } while (err == MFX_WRN_IN_EXECUTION);
    if (err < 0) {
        av_log(ctx, AV_LOG_ERROR, "Error synchronizing the operation\n");
        return AVERROR_UNKNOWN;
    }

    if (realigned) {
        out->Info.CropW = tmp_info.CropW;
        out->Info.CropH = tmp_info.CropH;
    }

    return 0;
}

static int qsv_frames_derive_to(AVHWFramesContext *dst_ctx,
                                AVHWFramesContext *src_ctx, int flags)
{
    QSVFramesContext *s = dst_ctx->internal->priv;
    AVQSVFramesContext *dst_hwctx = dst_ctx->hwctx;
    int i;

    if (src_ctx->initial_pool_size == 0) {
        av_log(dst_ctx, AV_LOG_ERROR, "Only fixed-size pools can be "
            "mapped to QSV frames.\n");
        return AVERROR(EINVAL);
    }

    switch (src_ctx->device_ctx->type) {
#if CONFIG_VAAPI
    case AV_HWDEVICE_TYPE_VAAPI:
        {
            AVVAAPIFramesContext *src_hwctx = src_ctx->hwctx;
            s->handle_pairs_internal = av_calloc(src_ctx->initial_pool_size,
                                                 sizeof(*s->handle_pairs_internal));
            if (!s->handle_pairs_internal)
                return AVERROR(ENOMEM);
            s->surfaces_internal = av_calloc(src_hwctx->nb_surfaces,
                                             sizeof(*s->surfaces_internal));
            if (!s->surfaces_internal)
                return AVERROR(ENOMEM);
            for (i = 0; i < src_hwctx->nb_surfaces; i++) {
                qsv_init_surface(dst_ctx, &s->surfaces_internal[i]);
                s->handle_pairs_internal[i].first = src_hwctx->surface_ids + i;
                s->handle_pairs_internal[i].second = (mfxMemId)MFX_INFINITE;
                s->surfaces_internal[i].Data.MemId = (mfxMemId)&s->handle_pairs_internal[i];
            }
            dst_hwctx->nb_surfaces = src_hwctx->nb_surfaces;
            dst_hwctx->frame_type  = MFX_MEMTYPE_VIDEO_MEMORY_DECODER_TARGET;
        }
        break;
#endif
#if CONFIG_D3D11VA
    case AV_HWDEVICE_TYPE_D3D11VA:
        {
            AVD3D11VAFramesContext *src_hwctx = src_ctx->hwctx;
            s->handle_pairs_internal = av_calloc(src_ctx->initial_pool_size,
                                                 sizeof(*s->handle_pairs_internal));
            if (!s->handle_pairs_internal)
                return AVERROR(ENOMEM);
            s->surfaces_internal = av_calloc(src_ctx->initial_pool_size,
                                             sizeof(*s->surfaces_internal));
            if (!s->surfaces_internal)
                return AVERROR(ENOMEM);
            for (i = 0; i < src_ctx->initial_pool_size; i++) {
                qsv_init_surface(dst_ctx, &s->surfaces_internal[i]);
                s->handle_pairs_internal[i].first = (mfxMemId)src_hwctx->texture_infos[i].texture;
                if (src_hwctx->BindFlags & D3D11_BIND_RENDER_TARGET) {
                    s->handle_pairs_internal[i].second = (mfxMemId)MFX_INFINITE;
                } else {
                    s->handle_pairs_internal[i].second = (mfxMemId)src_hwctx->texture_infos[i].index;
                }
                s->surfaces_internal[i].Data.MemId = (mfxMemId)&s->handle_pairs_internal[i];
            }
            dst_hwctx->nb_surfaces = src_ctx->initial_pool_size;
            if (src_hwctx->BindFlags & D3D11_BIND_RENDER_TARGET) {
                dst_hwctx->frame_type |= MFX_MEMTYPE_VIDEO_MEMORY_PROCESSOR_TARGET;
            } else {
                dst_hwctx->frame_type |= MFX_MEMTYPE_VIDEO_MEMORY_DECODER_TARGET;
            }
        }
        break;
#endif
#if CONFIG_DXVA2
    case AV_HWDEVICE_TYPE_DXVA2:
        {
            AVDXVA2FramesContext *src_hwctx = src_ctx->hwctx;
            s->handle_pairs_internal = av_calloc(src_ctx->initial_pool_size,
                                                 sizeof(*s->handle_pairs_internal));
            if (!s->handle_pairs_internal)
                return AVERROR(ENOMEM);
            s->surfaces_internal = av_calloc(src_hwctx->nb_surfaces,
                                             sizeof(*s->surfaces_internal));
            if (!s->surfaces_internal)
                return AVERROR(ENOMEM);
            for (i = 0; i < src_hwctx->nb_surfaces; i++) {
                qsv_init_surface(dst_ctx, &s->surfaces_internal[i]);
                s->handle_pairs_internal[i].first = (mfxMemId)src_hwctx->surfaces[i];
                s->handle_pairs_internal[i].second = (mfxMemId)MFX_INFINITE;
                s->surfaces_internal[i].Data.MemId = (mfxMemId)&s->handle_pairs_internal[i];
            }
            dst_hwctx->nb_surfaces = src_hwctx->nb_surfaces;
            if (src_hwctx->surface_type == DXVA2_VideoProcessorRenderTarget)
                dst_hwctx->frame_type = MFX_MEMTYPE_VIDEO_MEMORY_PROCESSOR_TARGET;
            else
                dst_hwctx->frame_type = MFX_MEMTYPE_VIDEO_MEMORY_DECODER_TARGET;
        }
        break;
#endif
    default:
        return AVERROR(ENOSYS);
    }

    dst_hwctx->surfaces = s->surfaces_internal;

    return 0;
}

static int qsv_map_to(AVHWFramesContext *dst_ctx,
                      AVFrame *dst, const AVFrame *src, int flags)
{
    AVQSVFramesContext *hwctx = dst_ctx->hwctx;
    int i, err, index = -1;

    for (i = 0; i < hwctx->nb_surfaces && index < 0; i++) {
        switch(src->format) {
#if CONFIG_VAAPI
        case AV_PIX_FMT_VAAPI:
        {
            mfxHDLPair *pair = (mfxHDLPair*)hwctx->surfaces[i].Data.MemId;
            if (*(VASurfaceID*)pair->first == (VASurfaceID)src->data[3]) {
                index = i;
                break;
            }
        }
#endif
#if CONFIG_D3D11VA
        case AV_PIX_FMT_D3D11:
        {
            mfxHDLPair *pair = (mfxHDLPair*)hwctx->surfaces[i].Data.MemId;
            if (pair->first == src->data[0]
                && pair->second == src->data[1]) {
                index = i;
                break;
            }
        }
#endif
#if CONFIG_DXVA2
        case AV_PIX_FMT_DXVA2_VLD:
        {
            mfxHDLPair *pair = (mfxHDLPair*)hwctx->surfaces[i].Data.MemId;
            if (pair->first == src->data[3]) {
                index = i;
                break;
            }
        }
#endif
        }
    }
    if (index < 0) {
        av_log(dst_ctx, AV_LOG_ERROR, "Trying to map from a surface which "
               "is not in the mapped frames context.\n");
        return AVERROR(EINVAL);
    }

    err = ff_hwframe_map_create(dst->hw_frames_ctx,
                                dst, src, NULL, NULL);
    if (err)
        return err;

    dst->width   = src->width;
    dst->height  = src->height;
    dst->data[3] = (uint8_t*)&hwctx->surfaces[index];

    return 0;
}

static int qsv_frames_get_constraints(AVHWDeviceContext *ctx,
                                      const void *hwconfig,
                                      AVHWFramesConstraints *constraints)
{
    int i;

    constraints->valid_sw_formats = av_malloc_array(FF_ARRAY_ELEMS(supported_pixel_formats) + 1,
                                                    sizeof(*constraints->valid_sw_formats));
    if (!constraints->valid_sw_formats)
        return AVERROR(ENOMEM);

    for (i = 0; i < FF_ARRAY_ELEMS(supported_pixel_formats); i++)
        constraints->valid_sw_formats[i] = supported_pixel_formats[i].pix_fmt;
    constraints->valid_sw_formats[FF_ARRAY_ELEMS(supported_pixel_formats)] = AV_PIX_FMT_NONE;

    constraints->valid_hw_formats = av_malloc_array(2, sizeof(*constraints->valid_hw_formats));
    if (!constraints->valid_hw_formats)
        return AVERROR(ENOMEM);

    constraints->valid_hw_formats[0] = AV_PIX_FMT_QSV;
    constraints->valid_hw_formats[1] = AV_PIX_FMT_NONE;

    return 0;
}

static void qsv_device_free(AVHWDeviceContext *ctx)
{
    AVQSVDeviceContext *hwctx = ctx->hwctx;
    QSVDevicePriv       *priv = ctx->user_opaque;

    if (hwctx->session)
        MFXClose(hwctx->session);

    av_buffer_unref(&priv->child_device_ctx);
    av_freep(&priv);
}

static mfxIMPL choose_implementation(const char *device, enum AVHWDeviceType child_device_type)
{
    static const struct {
        const char *name;
        mfxIMPL     impl;
    } impl_map[] = {
        { "auto",     MFX_IMPL_AUTO         },
        { "sw",       MFX_IMPL_SOFTWARE     },
        { "hw",       MFX_IMPL_HARDWARE     },
        { "auto_any", MFX_IMPL_AUTO_ANY     },
        { "hw_any",   MFX_IMPL_HARDWARE_ANY },
        { "hw2",      MFX_IMPL_HARDWARE2    },
        { "hw3",      MFX_IMPL_HARDWARE3    },
        { "hw4",      MFX_IMPL_HARDWARE4    },
    };

    mfxIMPL impl = MFX_IMPL_AUTO_ANY;
    int i;

    if (device) {
        for (i = 0; i < FF_ARRAY_ELEMS(impl_map); i++)
            if (!strcmp(device, impl_map[i].name)) {
                impl = impl_map[i].impl;
                break;
            }
        if (i == FF_ARRAY_ELEMS(impl_map))
            impl = strtol(device, NULL, 0);
    }

    if (impl != MFX_IMPL_SOFTWARE) {
        if (child_device_type == AV_HWDEVICE_TYPE_D3D11VA)
            impl |= MFX_IMPL_VIA_D3D11;
        else if (child_device_type == AV_HWDEVICE_TYPE_DXVA2)
            impl |= MFX_IMPL_VIA_D3D9;
    }

    return impl;
}

static int qsv_device_derive_from_child(AVHWDeviceContext *ctx,
                                        mfxIMPL implementation,
                                        AVHWDeviceContext *child_device_ctx,
                                        int flags)
{
    AVQSVDeviceContext *hwctx = ctx->hwctx;

    mfxVersion    ver = { { 3, 1 } };
    mfxHDL        handle;
    mfxHandleType handle_type;
    mfxStatus     err;
    int ret;

    switch (child_device_ctx->type) {
#if CONFIG_VAAPI
    case AV_HWDEVICE_TYPE_VAAPI:
        {
            AVVAAPIDeviceContext *child_device_hwctx = child_device_ctx->hwctx;
            handle_type = MFX_HANDLE_VA_DISPLAY;
            handle = (mfxHDL)child_device_hwctx->display;
        }
        break;
#endif
#if CONFIG_D3D11VA
    case AV_HWDEVICE_TYPE_D3D11VA:
        {
            AVD3D11VADeviceContext *child_device_hwctx = child_device_ctx->hwctx;
            handle_type = MFX_HANDLE_D3D11_DEVICE;
            handle = (mfxHDL)child_device_hwctx->device;
        }
        break;
#endif
#if CONFIG_DXVA2
    case AV_HWDEVICE_TYPE_DXVA2:
        {
            AVDXVA2DeviceContext *child_device_hwctx = child_device_ctx->hwctx;
            handle_type = MFX_HANDLE_D3D9_DEVICE_MANAGER;
            handle = (mfxHDL)child_device_hwctx->devmgr;
        }
        break;
#endif
    default:
        ret = AVERROR(ENOSYS);
        goto fail;
    }

    err = MFXInit(implementation, &ver, &hwctx->session);
    if (err != MFX_ERR_NONE) {
        av_log(ctx, AV_LOG_ERROR, "Error initializing an MFX session: "
               "%d.\n", err);
        ret = AVERROR_UNKNOWN;
        goto fail;
    }

    err = MFXQueryVersion(hwctx->session, &ver);
    if (err != MFX_ERR_NONE) {
        av_log(ctx, AV_LOG_ERROR, "Error querying an MFX session: %d.\n", err);
        ret = AVERROR_UNKNOWN;
        goto fail;
    }

    av_log(ctx, AV_LOG_VERBOSE,
           "Initialize MFX session: API version is %d.%d, implementation version is %d.%d\n",
           MFX_VERSION_MAJOR, MFX_VERSION_MINOR, ver.Major, ver.Minor);

    MFXClose(hwctx->session);

    err = MFXInit(implementation, &ver, &hwctx->session);
    if (err != MFX_ERR_NONE) {
        av_log(ctx, AV_LOG_ERROR,
               "Error initializing an MFX session: %d.\n", err);
        ret = AVERROR_UNKNOWN;
        goto fail;
    }

    err = MFXVideoCORE_SetHandle(hwctx->session, handle_type, handle);
    if (err != MFX_ERR_NONE) {
        av_log(ctx, AV_LOG_ERROR, "Error setting child device handle: "
               "%d\n", err);
        ret = AVERROR_UNKNOWN;
        goto fail;
    }

    return 0;

fail:
    if (hwctx->session)
        MFXClose(hwctx->session);
    return ret;
}

static int qsv_device_derive(AVHWDeviceContext *ctx,
                             AVHWDeviceContext *child_device_ctx,
                             AVDictionary *opts, int flags)
{
    mfxIMPL impl;
    impl = choose_implementation("hw_any", child_device_ctx->type);
    return qsv_device_derive_from_child(ctx, impl,
                                        child_device_ctx, flags);
}

static int qsv_device_create(AVHWDeviceContext *ctx, const char *device,
                             AVDictionary *opts, int flags)
{
    QSVDevicePriv *priv;
    enum AVHWDeviceType child_device_type;
    AVHWDeviceContext *child_device;
    AVDictionary *child_device_opts;
    AVDictionaryEntry *e;

    mfxIMPL impl;
    int ret;

    priv = av_mallocz(sizeof(*priv));
    if (!priv)
        return AVERROR(ENOMEM);

    ctx->user_opaque = priv;
    ctx->free        = qsv_device_free;

    e = av_dict_get(opts, "child_device_type", NULL, 0);
    if (e) {
        child_device_type = av_hwdevice_find_type_by_name(e->value);
        if (child_device_type == AV_HWDEVICE_TYPE_NONE) {
            av_log(ctx, AV_LOG_ERROR, "Unknown child device type "
                   "\"%s\".\n", e->value);
            return AVERROR(EINVAL);
        }
    } else if (CONFIG_VAAPI) {
        child_device_type = AV_HWDEVICE_TYPE_VAAPI;
    } else if (CONFIG_DXVA2) {
        av_log(NULL, AV_LOG_WARNING,
                "WARNING: defaulting child_device_type to AV_HWDEVICE_TYPE_DXVA2 for compatibility "
                "with old commandlines. This behaviour will be removed "
                "in the future. Please explicitly set device type via \"-init_hw_device\" option.\n");
        child_device_type = AV_HWDEVICE_TYPE_DXVA2;
    } else if (CONFIG_D3D11VA) {
        child_device_type = AV_HWDEVICE_TYPE_D3D11VA;
    } else {
        av_log(ctx, AV_LOG_ERROR, "No supported child device type is enabled\n");
        return AVERROR(ENOSYS);
    }

    child_device_opts = NULL;
    switch (child_device_type) {
#if CONFIG_VAAPI
    case AV_HWDEVICE_TYPE_VAAPI:
        {
            // libmfx does not actually implement VAAPI properly, rather it
            // depends on the specific behaviour of a matching iHD driver when
            // used on recent Intel hardware.  Set options to the VAAPI device
            // creation so that we should pick a usable setup by default if
            // possible, even when multiple devices and drivers are available.
            av_dict_set(&child_device_opts, "kernel_driver", "i915", 0);
            av_dict_set(&child_device_opts, "driver",        "iHD",  0);
        }
        break;
#endif
#if CONFIG_D3D11VA
    case AV_HWDEVICE_TYPE_D3D11VA:
        break;
#endif
#if CONFIG_DXVA2
    case AV_HWDEVICE_TYPE_DXVA2:
        break;
#endif
    default:
        {
            av_log(ctx, AV_LOG_ERROR, "No supported child device type is enabled\n");
            return AVERROR(ENOSYS);
        }
        break;
    }

    e = av_dict_get(opts, "child_device", NULL, 0);
    ret = av_hwdevice_ctx_create(&priv->child_device_ctx, child_device_type,
                                 e ? e->value : NULL, child_device_opts, 0);

    av_dict_free(&child_device_opts);
    if (ret < 0)
        return ret;

    child_device = (AVHWDeviceContext*)priv->child_device_ctx->data;

    impl = choose_implementation(device, child_device_type);

    return qsv_device_derive_from_child(ctx, impl, child_device, 0);
}

const HWContextType ff_hwcontext_type_qsv = {
    .type                   = AV_HWDEVICE_TYPE_QSV,
    .name                   = "QSV",

    .device_hwctx_size      = sizeof(AVQSVDeviceContext),
    .device_priv_size       = sizeof(QSVDeviceContext),
    .frames_hwctx_size      = sizeof(AVQSVFramesContext),
    .frames_priv_size       = sizeof(QSVFramesContext),

    .device_create          = qsv_device_create,
    .device_derive          = qsv_device_derive,
    .device_init            = qsv_device_init,
    .frames_get_constraints = qsv_frames_get_constraints,
    .frames_init            = qsv_frames_init,
    .frames_uninit          = qsv_frames_uninit,
    .frames_get_buffer      = qsv_get_buffer,
    .transfer_get_formats   = qsv_transfer_get_formats,
    .transfer_data_to       = qsv_transfer_data_to,
    .transfer_data_from     = qsv_transfer_data_from,
    .map_to                 = qsv_map_to,
    .map_from               = qsv_map_from,
    .frames_derive_to       = qsv_frames_derive_to,
    .frames_derive_from     = qsv_frames_derive_from,

    .pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_QSV, AV_PIX_FMT_NONE },
};