/* GStreamer
 * Copyright (C) 2024 Seungha Yang <seungha@centricular.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

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

#include "gstd3d12mipmapping.h"
#include "gstd3d12mipgen.h"
#include "gstd3d12pluginutils.h"
#include <directx/d3dx12.h>
#include <mutex>
#include <memory>
#include <queue>
#include <wrl.h>
#include <atomic>

/* *INDENT-OFF* */
using namespace Microsoft::WRL;
/* *INDENT-ON* */

GST_DEBUG_CATEGORY_STATIC (gst_d3d12_mip_mapping_debug);
#define GST_CAT_DEFAULT gst_d3d12_mip_mapping_debug

static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE_WITH_FEATURES
        (GST_CAPS_FEATURE_MEMORY_D3D12_MEMORY, GST_D3D12_ALL_FORMATS) "; "
        GST_VIDEO_CAPS_MAKE_WITH_FEATURES
        (GST_CAPS_FEATURE_MEMORY_D3D12_MEMORY ","
            GST_CAPS_FEATURE_META_GST_VIDEO_OVERLAY_COMPOSITION,
            GST_D3D12_ALL_FORMATS)));

static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE_WITH_FEATURES
        (GST_CAPS_FEATURE_MEMORY_D3D12_MEMORY, "RGBA") "; "
        GST_VIDEO_CAPS_MAKE_WITH_FEATURES
        (GST_CAPS_FEATURE_MEMORY_D3D12_MEMORY ","
            GST_CAPS_FEATURE_META_GST_VIDEO_OVERLAY_COMPOSITION,
            "RGBA")));

enum
{
  PROP_0,
  PROP_ASYNC_DEPTH,
};

#define DEFAULT_ASYNC_DEPTH 0

/* *INDENT-OFF* */
struct MipMappingContext
{
  MipMappingContext (GstD3D12Device * dev)
  {
    device = (GstD3D12Device *) gst_object_ref (dev);
    auto device_handle = gst_d3d12_device_get_device_handle (device);
    ca_pool = gst_d3d12_cmd_alloc_pool_new (device_handle,
        D3D12_COMMAND_LIST_TYPE_DIRECT);
  }

   ~MipMappingContext ()
  {
    gst_d3d12_device_fence_wait (device, D3D12_COMMAND_LIST_TYPE_DIRECT,
        fence_val);

    gst_clear_object (&ca_pool);
    gst_clear_object (&conv);
    gst_clear_object (&gen);
    gst_clear_object (&device);
  }

  GstD3D12Device *device = nullptr;
  GstD3D12Converter *conv = nullptr;
  GstD3D12MipGen *gen = nullptr;
  ComPtr<ID3D12GraphicsCommandList> cl;
  std::queue<guint64> scheduled;
  GstD3D12CmdAllocPool *ca_pool;
  guint64 fence_val = 0;
};

struct GstD3D12MipMappingPrivate
{
  GstD3D12MipMappingPrivate ()
  {
    fence_data_pool = gst_d3d12_fence_data_pool_new ();
  }

  ~GstD3D12MipMappingPrivate ()
  {
    gst_clear_object (&fence_data_pool);
  }

  std::unique_ptr < MipMappingContext > ctx;
  GstD3D12FenceDataPool *fence_data_pool;
  D3D12_BOX in_rect = { };
  D3D12_BOX prev_in_rect = { };

  std::atomic<guint> async_depth = { DEFAULT_ASYNC_DEPTH };

  std::mutex lock;
};
/* *INDENT-ON* */

struct _GstD3D12MipMapping
{
  GstD3D12BaseFilter parent;

  GstD3D12MipMappingPrivate *priv;
};

static void gst_d3d12_mip_mapping_finalize (GObject * object);
static void gst_d3d12_mip_mapping_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_d3d12_mip_mapping_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);
static gboolean gst_d3d12_mip_mapping_stop (GstBaseTransform * trans);
static GstCaps *gst_d3d12_mip_mapping_transform_caps (GstBaseTransform *
    trans, GstPadDirection direction, GstCaps * caps, GstCaps * filter);
static GstCaps *gst_d3d12_mip_mapping_fixate_caps (GstBaseTransform *
    base, GstPadDirection direction, GstCaps * caps, GstCaps * othercaps);
static gboolean gst_d3d12_mip_mapping_propose_allocation (GstBaseTransform *
    trans, GstQuery * decide_query, GstQuery * query);
static gboolean gst_d3d12_mip_mapping_decide_allocation (GstBaseTransform *
    trans, GstQuery * query);
static gboolean gst_d3d12_mip_mapping_transform_meta (GstBaseTransform * trans,
    GstBuffer * outbuf, GstMeta * meta, GstBuffer * inbuf);
static GstFlowReturn gst_d3d12_mip_mapping_transform (GstBaseTransform * trans,
    GstBuffer * inbuf, GstBuffer * outbuf);
static gboolean gst_d3d12_mip_mapping_set_info (GstD3D12BaseFilter * filter,
    GstCaps * incaps, GstVideoInfo * in_info, GstCaps * outcaps,
    GstVideoInfo * out_info);

#define gst_d3d12_mip_mapping_parent_class parent_class
G_DEFINE_TYPE (GstD3D12MipMapping, gst_d3d12_mip_mapping,
    GST_TYPE_D3D12_BASE_FILTER);

static void
gst_d3d12_mip_mapping_class_init (GstD3D12MipMappingClass * klass)
{
  auto object_class = G_OBJECT_CLASS (klass);
  auto element_class = GST_ELEMENT_CLASS (klass);
  auto trans_class = GST_BASE_TRANSFORM_CLASS (klass);
  auto filter_class = GST_D3D12_BASE_FILTER_CLASS (klass);

  object_class->set_property = gst_d3d12_mip_mapping_set_property;
  object_class->get_property = gst_d3d12_mip_mapping_get_property;
  object_class->finalize = gst_d3d12_mip_mapping_finalize;

  g_object_class_install_property (object_class, PROP_ASYNC_DEPTH,
      g_param_spec_uint ("async-depth", "Async Depth",
          "Number of in-flight GPU commands which can be scheduled without "
          "synchronization (0 = unlimited)", 0, G_MAXINT, DEFAULT_ASYNC_DEPTH,
          (GParamFlags) (GST_PARAM_MUTABLE_PLAYING |
              G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));

  gst_element_class_add_static_pad_template (element_class, &sink_template);
  gst_element_class_add_static_pad_template (element_class, &src_template);

  gst_element_class_set_static_metadata (element_class,
      "Direct3D12 MipMapping",
      "Filter/Converter/Video/Hardware",
      "Generates RGBA MipMap texture from input",
      "Seungha Yang <seungha@centricular.com>");

  trans_class->passthrough_on_same_caps = FALSE;

  trans_class->stop = GST_DEBUG_FUNCPTR (gst_d3d12_mip_mapping_stop);
  trans_class->transform_caps =
      GST_DEBUG_FUNCPTR (gst_d3d12_mip_mapping_transform_caps);
  trans_class->fixate_caps =
      GST_DEBUG_FUNCPTR (gst_d3d12_mip_mapping_fixate_caps);
  trans_class->propose_allocation =
      GST_DEBUG_FUNCPTR (gst_d3d12_mip_mapping_propose_allocation);
  trans_class->decide_allocation =
      GST_DEBUG_FUNCPTR (gst_d3d12_mip_mapping_decide_allocation);
  trans_class->transform_meta =
      GST_DEBUG_FUNCPTR (gst_d3d12_mip_mapping_transform_meta);
  trans_class->transform = GST_DEBUG_FUNCPTR (gst_d3d12_mip_mapping_transform);

  filter_class->set_info = GST_DEBUG_FUNCPTR (gst_d3d12_mip_mapping_set_info);

  gst_type_mark_as_plugin_api (GST_TYPE_D3D12_SAMPLING_METHOD,
      (GstPluginAPIFlags) 0);

  GST_DEBUG_CATEGORY_INIT (gst_d3d12_mip_mapping_debug, "d3d12mipmapping", 0,
      "d3d12mipmapping");
}

static void
gst_d3d12_mip_mapping_init (GstD3D12MipMapping * self)
{
  self->priv = new GstD3D12MipMappingPrivate ();
}

static void
gst_d3d12_mip_mapping_finalize (GObject * object)
{
  auto self = GST_D3D12_MIP_MAPPING (object);

  delete self->priv;

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

static void
gst_d3d12_mip_mapping_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  auto self = GST_D3D12_MIP_MAPPING (object);
  auto priv = self->priv;

  switch (prop_id) {
    case PROP_ASYNC_DEPTH:
      priv->async_depth = g_value_get_uint (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_d3d12_mip_mapping_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  auto self = GST_D3D12_MIP_MAPPING (object);
  auto priv = self->priv;

  switch (prop_id) {
    case PROP_ASYNC_DEPTH:
      g_value_set_uint (value, priv->async_depth);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static gboolean
gst_d3d12_mip_mapping_stop (GstBaseTransform * trans)
{
  auto self = GST_D3D12_MIP_MAPPING (trans);
  auto priv = self->priv;

  priv->ctx = nullptr;

  return GST_BASE_TRANSFORM_CLASS (parent_class)->stop (trans);
}

static GstCaps *
gst_d3d12_mip_mapping_caps_remove_format_info (GstCaps * caps)
{
  GstStructure *st;
  GstCapsFeatures *f;
  gint i, n;
  GstCaps *res;
  GstCapsFeatures *feature =
      gst_caps_features_from_string (GST_CAPS_FEATURE_MEMORY_D3D12_MEMORY);

  res = gst_caps_new_empty ();

  n = gst_caps_get_size (caps);
  for (i = 0; i < n; i++) {
    st = gst_caps_get_structure (caps, i);
    f = gst_caps_get_features (caps, i);

    /* If this is already expressed by the existing caps
     * skip this structure */
    if (i > 0 && gst_caps_is_subset_structure_full (res, st, f))
      continue;

    st = gst_structure_copy (st);
    /* Only remove format info for the cases when we can actually convert */
    if (!gst_caps_features_is_any (f)
        && gst_caps_features_is_equal (f, feature)) {
      gst_structure_remove_fields (st, "format", "colorimetry", "chroma-site",
          NULL);
    }

    gst_caps_append_structure_full (res, st, gst_caps_features_copy (f));
  }
  gst_caps_features_free (feature);

  return res;
}

static GstCaps *
gst_d3d12_mip_mapping_transform_caps (GstBaseTransform *
    trans, GstPadDirection direction, GstCaps * caps, GstCaps * filter)
{
  GstCaps *tmp, *tmp2;
  GstCaps *result;

  /* Get all possible caps that we can transform to */
  tmp = gst_d3d12_mip_mapping_caps_remove_format_info (caps);

  if (filter) {
    tmp2 = gst_caps_intersect_full (filter, tmp, GST_CAPS_INTERSECT_FIRST);
    gst_caps_unref (tmp);
    tmp = tmp2;
  }

  result = tmp;

  GST_DEBUG_OBJECT (trans, "transformed %" GST_PTR_FORMAT " into %"
      GST_PTR_FORMAT, caps, result);

  return result;
}

/*
 * This is an incomplete matrix of in formats and a score for the prefered output
 * format.
 *
 *         out: RGB24   RGB16  ARGB  AYUV  YUV444  YUV422 YUV420 YUV411 YUV410  PAL  GRAY
 *  in
 * RGB24          0      2       1     2     2       3      4      5      6      7    8
 * RGB16          1      0       1     2     2       3      4      5      6      7    8
 * ARGB           2      3       0     1     4       5      6      7      8      9    10
 * AYUV           3      4       1     0     2       5      6      7      8      9    10
 * YUV444         2      4       3     1     0       5      6      7      8      9    10
 * YUV422         3      5       4     2     1       0      6      7      8      9    10
 * YUV420         4      6       5     3     2       1      0      7      8      9    10
 * YUV411         4      6       5     3     2       1      7      0      8      9    10
 * YUV410         6      8       7     5     4       3      2      1      0      9    10
 * PAL            1      3       2     6     4       6      7      8      9      0    10
 * GRAY           1      4       3     2     1       5      6      7      8      9    0
 *
 * PAL or GRAY are never prefered, if we can we would convert to PAL instead
 * of GRAY, though
 * less subsampling is prefered and if any, preferably horizontal
 * We would like to keep the alpha, even if we would need to to colorspace conversion
 * or lose depth.
 */
#define SCORE_FORMAT_CHANGE       1
#define SCORE_DEPTH_CHANGE        1
#define SCORE_ALPHA_CHANGE        1
#define SCORE_CHROMA_W_CHANGE     1
#define SCORE_CHROMA_H_CHANGE     1
#define SCORE_PALETTE_CHANGE      1

#define SCORE_COLORSPACE_LOSS     2     /* RGB <-> YUV */
#define SCORE_DEPTH_LOSS          4     /* change bit depth */
#define SCORE_ALPHA_LOSS          8     /* lose the alpha channel */
#define SCORE_CHROMA_W_LOSS      16     /* vertical subsample */
#define SCORE_CHROMA_H_LOSS      32     /* horizontal subsample */
#define SCORE_PALETTE_LOSS       64     /* convert to palette format */
#define SCORE_COLOR_LOSS        128     /* convert to GRAY */

#define COLORSPACE_MASK (GST_VIDEO_FORMAT_FLAG_YUV | \
                         GST_VIDEO_FORMAT_FLAG_RGB | GST_VIDEO_FORMAT_FLAG_GRAY)
#define ALPHA_MASK      (GST_VIDEO_FORMAT_FLAG_ALPHA)
#define PALETTE_MASK    (GST_VIDEO_FORMAT_FLAG_PALETTE)

/* calculate how much loss a conversion would be */
static void
score_value (GstBaseTransform * base, const GstVideoFormatInfo * in_info,
    const GValue * val, gint * min_loss, const GstVideoFormatInfo ** out_info)
{
  const gchar *fname;
  const GstVideoFormatInfo *t_info;
  guint in_flags, t_flags;
  gint loss;

  fname = g_value_get_string (val);
  t_info = gst_video_format_get_info (gst_video_format_from_string (fname));
  if (!t_info || t_info->format == GST_VIDEO_FORMAT_UNKNOWN)
    return;

  /* accept input format immediately without loss */
  if (in_info == t_info) {
    *min_loss = 0;
    *out_info = t_info;
    return;
  }

  loss = SCORE_FORMAT_CHANGE;

  in_flags = GST_VIDEO_FORMAT_INFO_FLAGS (in_info);
  in_flags &= ~GST_VIDEO_FORMAT_FLAG_LE;
  in_flags &= ~GST_VIDEO_FORMAT_FLAG_COMPLEX;
  in_flags &= ~GST_VIDEO_FORMAT_FLAG_UNPACK;

  t_flags = GST_VIDEO_FORMAT_INFO_FLAGS (t_info);
  t_flags &= ~GST_VIDEO_FORMAT_FLAG_LE;
  t_flags &= ~GST_VIDEO_FORMAT_FLAG_COMPLEX;
  t_flags &= ~GST_VIDEO_FORMAT_FLAG_UNPACK;

  if ((t_flags & PALETTE_MASK) != (in_flags & PALETTE_MASK)) {
    loss += SCORE_PALETTE_CHANGE;
    if (t_flags & PALETTE_MASK)
      loss += SCORE_PALETTE_LOSS;
  }

  if ((t_flags & COLORSPACE_MASK) != (in_flags & COLORSPACE_MASK)) {
    loss += SCORE_COLORSPACE_LOSS;
    if (t_flags & GST_VIDEO_FORMAT_FLAG_GRAY)
      loss += SCORE_COLOR_LOSS;
  }

  if ((t_flags & ALPHA_MASK) != (in_flags & ALPHA_MASK)) {
    loss += SCORE_ALPHA_CHANGE;
    if (in_flags & ALPHA_MASK)
      loss += SCORE_ALPHA_LOSS;
  }

  if ((in_info->h_sub[1]) != (t_info->h_sub[1])) {
    loss += SCORE_CHROMA_H_CHANGE;
    if ((in_info->h_sub[1]) < (t_info->h_sub[1]))
      loss += SCORE_CHROMA_H_LOSS;
  }
  if ((in_info->w_sub[1]) != (t_info->w_sub[1])) {
    loss += SCORE_CHROMA_W_CHANGE;
    if ((in_info->w_sub[1]) < (t_info->w_sub[1]))
      loss += SCORE_CHROMA_W_LOSS;
  }

  if ((in_info->bits) != (t_info->bits)) {
    loss += SCORE_DEPTH_CHANGE;
    if ((in_info->bits) > (t_info->bits))
      loss += SCORE_DEPTH_LOSS + (in_info->bits - t_info->bits);
  }

  GST_DEBUG_OBJECT (base, "score %s -> %s = %d",
      GST_VIDEO_FORMAT_INFO_NAME (in_info),
      GST_VIDEO_FORMAT_INFO_NAME (t_info), loss);

  if (loss < *min_loss) {
    GST_DEBUG_OBJECT (base, "found new best %d", loss);
    *out_info = t_info;
    *min_loss = loss;
  }
}

static void
gst_d3d12_mip_mapping_fixate_format (GstBaseTransform * trans, GstCaps * caps,
    GstCaps * result)
{
  GstStructure *ins, *outs;
  const gchar *in_format;
  const GstVideoFormatInfo *in_info, *out_info = nullptr;
  gint min_loss = G_MAXINT;
  guint i, capslen;

  ins = gst_caps_get_structure (caps, 0);
  in_format = gst_structure_get_string (ins, "format");
  if (!in_format) {
    return;
  }

  GST_DEBUG_OBJECT (trans, "source format %s", in_format);

  in_info =
      gst_video_format_get_info (gst_video_format_from_string (in_format));
  if (!in_info)
    return;

  outs = gst_caps_get_structure (result, 0);

  capslen = gst_caps_get_size (result);
  GST_DEBUG ("iterate %d structures", capslen);
  for (i = 0; i < capslen; i++) {
    GstStructure *tests;
    const GValue *format;

    tests = gst_caps_get_structure (result, i);
    format = gst_structure_get_value (tests, "format");

    /* should not happen */
    if (format == nullptr)
      continue;

    if (GST_VALUE_HOLDS_LIST (format)) {
      gint j, len;

      len = gst_value_list_get_size (format);
      GST_DEBUG_OBJECT (trans, "have %d formats", len);
      for (j = 0; j < len; j++) {
        const GValue *val;

        val = gst_value_list_get_value (format, j);
        if (G_VALUE_HOLDS_STRING (val)) {
          score_value (trans, in_info, val, &min_loss, &out_info);
          if (min_loss == 0)
            break;
        }
      }
    } else if (G_VALUE_HOLDS_STRING (format)) {
      score_value (trans, in_info, format, &min_loss, &out_info);
    }
  }
  if (out_info)
    gst_structure_set (outs, "format", G_TYPE_STRING,
        GST_VIDEO_FORMAT_INFO_NAME (out_info), nullptr);
}

static gboolean
subsampling_unchanged (GstVideoInfo * in_info, GstVideoInfo * out_info)
{
  guint i;
  const GstVideoFormatInfo *in_format, *out_format;

  if (GST_VIDEO_INFO_N_COMPONENTS (in_info) !=
      GST_VIDEO_INFO_N_COMPONENTS (out_info))
    return FALSE;

  in_format = in_info->finfo;
  out_format = out_info->finfo;

  for (i = 0; i < GST_VIDEO_INFO_N_COMPONENTS (in_info); i++) {
    if (GST_VIDEO_FORMAT_INFO_W_SUB (in_format,
            i) != GST_VIDEO_FORMAT_INFO_W_SUB (out_format, i))
      return FALSE;
    if (GST_VIDEO_FORMAT_INFO_H_SUB (in_format,
            i) != GST_VIDEO_FORMAT_INFO_H_SUB (out_format, i))
      return FALSE;
  }

  return TRUE;
}

static void
transfer_colorimetry_from_input (GstBaseTransform * trans, GstCaps * in_caps,
    GstCaps * out_caps)
{
  GstStructure *out_caps_s = gst_caps_get_structure (out_caps, 0);
  GstStructure *in_caps_s = gst_caps_get_structure (in_caps, 0);
  gboolean have_colorimetry =
      gst_structure_has_field (out_caps_s, "colorimetry");
  gboolean have_chroma_site =
      gst_structure_has_field (out_caps_s, "chroma-site");

  /* If the output already has colorimetry and chroma-site, stop,
   * otherwise try and transfer what we can from the input caps */
  if (have_colorimetry && have_chroma_site)
    return;

  {
    GstVideoInfo in_info, out_info;
    const GValue *in_colorimetry =
        gst_structure_get_value (in_caps_s, "colorimetry");

    if (!gst_video_info_from_caps (&in_info, in_caps)) {
      GST_WARNING_OBJECT (trans,
          "Failed to convert sink pad caps to video info");
      return;
    }
    if (!gst_video_info_from_caps (&out_info, out_caps)) {
      GST_WARNING_OBJECT (trans,
          "Failed to convert src pad caps to video info");
      return;
    }

    if (!have_colorimetry && in_colorimetry != nullptr) {
      if ((GST_VIDEO_INFO_IS_YUV (&out_info)
              && GST_VIDEO_INFO_IS_YUV (&in_info))
          || (GST_VIDEO_INFO_IS_RGB (&out_info)
              && GST_VIDEO_INFO_IS_RGB (&in_info))
          || (GST_VIDEO_INFO_IS_GRAY (&out_info)
              && GST_VIDEO_INFO_IS_GRAY (&in_info))) {
        /* Can transfer the colorimetry intact from the input if it has it */
        gst_structure_set_value (out_caps_s, "colorimetry", in_colorimetry);
      } else {
        gchar *colorimetry_str;

        /* Changing between YUV/RGB - forward primaries and transfer function, but use
         * default range and matrix.
         * the primaries is used for conversion between RGB and XYZ (CIE 1931 coordinate).
         * the transfer function could be another reference (e.g., HDR)
         */
        out_info.colorimetry.primaries = in_info.colorimetry.primaries;
        out_info.colorimetry.transfer = in_info.colorimetry.transfer;

        colorimetry_str =
            gst_video_colorimetry_to_string (&out_info.colorimetry);
        gst_caps_set_simple (out_caps, "colorimetry", G_TYPE_STRING,
            colorimetry_str, nullptr);
        g_free (colorimetry_str);
      }
    }

    /* Only YUV output needs chroma-site. If the input was also YUV and had the same chroma
     * subsampling, transfer the siting. If the sub-sampling is changing, then the planes get
     * scaled anyway so there's no real reason to prefer the input siting. */
    if (!have_chroma_site && GST_VIDEO_INFO_IS_YUV (&out_info)) {
      if (GST_VIDEO_INFO_IS_YUV (&in_info)) {
        const GValue *in_chroma_site =
            gst_structure_get_value (in_caps_s, "chroma-site");
        if (in_chroma_site != nullptr
            && subsampling_unchanged (&in_info, &out_info))
          gst_structure_set_value (out_caps_s, "chroma-site", in_chroma_site);
      }
    }
  }
}

static GstCaps *
gst_d3d12_mip_mapping_get_fixed_format (GstBaseTransform * trans,
    GstPadDirection direction, GstCaps * caps, GstCaps * othercaps)
{
  GstCaps *result;

  result = gst_caps_intersect (othercaps, caps);
  if (gst_caps_is_empty (result)) {
    gst_caps_unref (result);
    result = gst_caps_copy (othercaps);
  }

  gst_d3d12_mip_mapping_fixate_format (trans, caps, result);

  /* fixate remaining fields */
  result = gst_caps_fixate (result);

  if (direction == GST_PAD_SINK) {
    if (gst_caps_is_subset (caps, result)) {
      gst_caps_replace (&result, caps);
    } else {
      /* Try and preserve input colorimetry / chroma information */
      transfer_colorimetry_from_input (trans, caps, result);
    }
  }

  return result;
}

static GstCaps *
gst_d3d12_mip_mapping_fixate_caps (GstBaseTransform * trans,
    GstPadDirection direction, GstCaps * caps, GstCaps * othercaps)
{
  GST_DEBUG_OBJECT (trans,
      "trying to fixate othercaps %" GST_PTR_FORMAT " based on caps %"
      GST_PTR_FORMAT, othercaps, caps);

  auto format = gst_d3d12_mip_mapping_get_fixed_format (trans, direction, caps,
      othercaps);
  gst_caps_unref (othercaps);

  if (gst_caps_is_empty (format)) {
    GST_ERROR_OBJECT (trans, "Could not convert formats");
  } else {
    GST_DEBUG_OBJECT (trans, "fixated othercaps to %" GST_PTR_FORMAT, format);
  }

  return format;
}

static gboolean
gst_d3d12_mip_mapping_propose_allocation (GstBaseTransform * trans,
    GstQuery * decide_query, GstQuery * query)
{
  auto filter = GST_D3D12_BASE_FILTER (trans);
  GstVideoInfo info;
  GstBufferPool *pool = nullptr;
  GstCaps *caps;
  guint n_pools, i;
  guint size;

  if (!GST_BASE_TRANSFORM_CLASS (parent_class)->propose_allocation (trans,
          decide_query, query)) {
    return FALSE;
  }

  gst_query_parse_allocation (query, &caps, nullptr);

  if (!caps)
    return FALSE;

  if (!gst_video_info_from_caps (&info, caps)) {
    GST_ERROR_OBJECT (filter, "Invalid caps %" GST_PTR_FORMAT, caps);
    return FALSE;
  }

  n_pools = gst_query_get_n_allocation_pools (query);
  for (i = 0; i < n_pools; i++) {
    gst_query_parse_nth_allocation_pool (query, i, &pool, nullptr, nullptr,
        nullptr);
    if (pool) {
      if (!GST_IS_D3D12_BUFFER_POOL (pool)) {
        gst_clear_object (&pool);
      } else {
        auto dpool = GST_D3D12_BUFFER_POOL (pool);
        if (!gst_d3d12_device_is_equal (dpool->device, filter->device))
          gst_clear_object (&pool);
      }
    }
  }

  if (!pool)
    pool = gst_d3d12_buffer_pool_new (filter->device);

  auto config = gst_buffer_pool_get_config (pool);
  gst_buffer_pool_config_add_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META);

  auto d3d12_params =
      gst_buffer_pool_config_get_d3d12_allocation_params (config);
  if (!d3d12_params) {
    d3d12_params = gst_d3d12_allocation_params_new (filter->device, &info,
        GST_D3D12_ALLOCATION_FLAG_DEFAULT,
        D3D12_RESOURCE_FLAG_ALLOW_SIMULTANEOUS_ACCESS, D3D12_HEAP_FLAG_NONE);
  } else {
    gst_d3d12_allocation_params_set_resource_flags (d3d12_params,
        D3D12_RESOURCE_FLAG_ALLOW_SIMULTANEOUS_ACCESS);
    gst_d3d12_allocation_params_unset_resource_flags (d3d12_params,
        D3D12_RESOURCE_FLAG_DENY_SHADER_RESOURCE);
  }

  gst_buffer_pool_config_set_d3d12_allocation_params (config, d3d12_params);
  gst_d3d12_allocation_params_free (d3d12_params);

  /* size will be updated by d3d12 buffer pool */
  gst_buffer_pool_config_set_params (config, caps, 0, 0, 0);

  if (!gst_buffer_pool_set_config (pool, config)) {
    GST_ERROR_OBJECT (filter, "failed to set config");
    gst_object_unref (pool);
    return FALSE;
  }

  gst_query_add_allocation_meta (query, GST_VIDEO_META_API_TYPE, nullptr);
  gst_query_add_allocation_meta (query,
      GST_VIDEO_OVERLAY_COMPOSITION_META_API_TYPE, nullptr);
  gst_query_add_allocation_meta (query, GST_VIDEO_CROP_META_API_TYPE, nullptr);

  /* d3d12 buffer pool will update buffer size based on allocated texture,
   * get size from config again */
  config = gst_buffer_pool_get_config (pool);
  gst_buffer_pool_config_get_params (config, nullptr, &size, nullptr, nullptr);
  gst_structure_free (config);

  gst_query_add_allocation_pool (query, pool, size, 0, 0);

  gst_object_unref (pool);

  return TRUE;
}

static gboolean
gst_d3d12_mip_mapping_decide_allocation (GstBaseTransform * trans,
    GstQuery * query)
{
  auto filter = GST_D3D12_BASE_FILTER (trans);
  GstCaps *outcaps = nullptr;
  GstBufferPool *pool = nullptr;
  guint size, min = 0, max = 0;
  GstStructure *config;
  gboolean update_pool = FALSE;
  GstVideoInfo info;

  gst_query_parse_allocation (query, &outcaps, nullptr);

  if (!outcaps)
    return FALSE;

  if (!gst_video_info_from_caps (&info, outcaps)) {
    GST_ERROR_OBJECT (filter, "Invalid caps %" GST_PTR_FORMAT, outcaps);
    return FALSE;
  }

  size = GST_VIDEO_INFO_SIZE (&info);
  if (gst_query_get_n_allocation_pools (query) > 0) {
    gst_query_parse_nth_allocation_pool (query, 0, &pool, &size, &min, &max);
    if (pool) {
      if (!GST_IS_D3D12_BUFFER_POOL (pool)) {
        gst_clear_object (&pool);
      } else {
        auto dpool = GST_D3D12_BUFFER_POOL (pool);
        if (!gst_d3d12_device_is_equal (dpool->device, filter->device))
          gst_clear_object (&pool);
      }
    }

    update_pool = TRUE;
  }

  if (!pool)
    pool = gst_d3d12_buffer_pool_new (filter->device);

  config = gst_buffer_pool_get_config (pool);
  gst_buffer_pool_config_add_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META);

  D3D12_RESOURCE_FLAGS resource_flags =
      D3D12_RESOURCE_FLAG_ALLOW_SIMULTANEOUS_ACCESS |
      D3D12_RESOURCE_FLAG_ALLOW_UNORDERED_ACCESS |
      D3D12_RESOURCE_FLAG_ALLOW_RENDER_TARGET;

  auto d3d12_params = gst_d3d12_allocation_params_new (filter->device, &info,
      GST_D3D12_ALLOCATION_FLAG_DEFAULT, resource_flags,
      D3D12_HEAP_FLAG_SHARED);

  /* Auto generate mip maps */
  gst_d3d12_allocation_params_set_mip_levels (d3d12_params, 0);

  gst_buffer_pool_config_set_d3d12_allocation_params (config, d3d12_params);
  gst_d3d12_allocation_params_free (d3d12_params);

  gst_buffer_pool_config_set_params (config, outcaps, size, min, max);
  gst_buffer_pool_set_config (pool, config);

  /* d3d12 buffer pool will update buffer size based on allocated texture,
   * get size from config again */
  config = gst_buffer_pool_get_config (pool);
  gst_buffer_pool_config_get_params (config, nullptr, &size, nullptr, nullptr);
  gst_structure_free (config);

  if (update_pool)
    gst_query_set_nth_allocation_pool (query, 0, pool, size, min, max);
  else
    gst_query_add_allocation_pool (query, pool, size, min, max);

  gst_object_unref (pool);

  return GST_BASE_TRANSFORM_CLASS (parent_class)->decide_allocation (trans,
      query);
}

static gboolean
gst_d3d12_mip_mapping_set_info (GstD3D12BaseFilter * filter,
    GstCaps * incaps, GstVideoInfo * in_info, GstCaps * outcaps,
    GstVideoInfo * out_info)
{
  auto self = GST_D3D12_MIP_MAPPING (filter);
  auto priv = self->priv;

  priv->ctx = nullptr;

  GST_DEBUG_OBJECT (self, "Setup convert with format %s -> %s",
      gst_video_format_to_string (GST_VIDEO_INFO_FORMAT (in_info)),
      gst_video_format_to_string (GST_VIDEO_INFO_FORMAT (out_info)));

  /* if present, these must match */
  if (in_info->interlace_mode != out_info->interlace_mode) {
    GST_ERROR_OBJECT (self, "input and output formats do not match");
    return FALSE;
  }

  auto ctx = std::make_unique < MipMappingContext > (filter->device);

  ctx->conv = gst_d3d12_converter_new (filter->device, nullptr, in_info,
      out_info, nullptr, nullptr, nullptr);
  if (!ctx->conv) {
    GST_ERROR_OBJECT (self, "Couldn't create converter");
    return FALSE;
  }

  ctx->gen = gst_d3d12_mip_gen_new (filter->device);
  if (!ctx->gen) {
    GST_ERROR_OBJECT (self, "Couldn't create mip generator");
    return FALSE;
  }

  priv->in_rect = CD3DX12_BOX (0, 0,
      GST_VIDEO_INFO_WIDTH (in_info), GST_VIDEO_INFO_HEIGHT (in_info));
  priv->prev_in_rect = priv->in_rect;

  priv->ctx = std::move (ctx);

  return TRUE;
}

static gboolean
gst_d3d12_mip_mapping_transform_meta (GstBaseTransform * trans,
    GstBuffer * outbuf, GstMeta * meta, GstBuffer * inbuf)
{
  if (meta->info->api == GST_VIDEO_CROP_META_API_TYPE)
    return FALSE;

  return GST_BASE_TRANSFORM_CLASS (parent_class)->transform_meta (trans,
      outbuf, meta, inbuf);
}

static GstFlowReturn
gst_d3d12_mip_mapping_transform (GstBaseTransform * trans, GstBuffer * inbuf,
    GstBuffer * outbuf)
{
  auto self = GST_D3D12_MIP_MAPPING (trans);
  auto priv = self->priv;
  D3D12_BOX in_rect;

  auto crop_meta = gst_buffer_get_video_crop_meta (inbuf);
  if (crop_meta) {
    GST_LOG_OBJECT (self, "Have crop rect, x:y:w:h = %d:%d:%d:%d",
        crop_meta->x, crop_meta->y, crop_meta->width, crop_meta->height);

    in_rect = CD3DX12_BOX (crop_meta->x, crop_meta->y,
        crop_meta->x + crop_meta->width, crop_meta->y + crop_meta->height);
  } else {
    in_rect = priv->in_rect;
  }

  if (in_rect != priv->in_rect) {
    priv->prev_in_rect = in_rect;
    g_object_set (priv->ctx->conv, "src-x", (gint) in_rect.left,
        "src-y", (gint) in_rect.top,
        "src-width", (gint) in_rect.right - in_rect.left,
        "src-height", (gint) in_rect.bottom - in_rect.top, nullptr);
  }

  GstD3D12CmdAlloc *gst_ca;
  if (!gst_d3d12_cmd_alloc_pool_acquire (priv->ctx->ca_pool, &gst_ca)) {
    GST_ERROR_OBJECT (self, "Couldn't acquire command allocator");
    return GST_FLOW_ERROR;
  }

  auto ca = gst_d3d12_cmd_alloc_get_handle (gst_ca);
  auto hr = ca->Reset ();
  if (!gst_d3d12_result (hr, priv->ctx->device)) {
    GST_ERROR_OBJECT (self, "Couldn't reset command allocator");
    gst_d3d12_cmd_alloc_unref (gst_ca);
    return GST_FLOW_ERROR;
  }

  if (!priv->ctx->cl) {
    auto device = gst_d3d12_device_get_device_handle (priv->ctx->device);
    hr = device->CreateCommandList (0, D3D12_COMMAND_LIST_TYPE_DIRECT,
        ca, nullptr, IID_PPV_ARGS (&priv->ctx->cl));
    if (!gst_d3d12_result (hr, priv->ctx->device)) {
      GST_ERROR_OBJECT (self, "Couldn't create command list");
      gst_d3d12_cmd_alloc_unref (gst_ca);
      return GST_FLOW_ERROR;
    }
  } else {
    hr = priv->ctx->cl->Reset (ca, nullptr);
    if (!gst_d3d12_result (hr, priv->ctx->device)) {
      GST_ERROR_OBJECT (self, "Couldn't reset command list");
      gst_d3d12_cmd_alloc_unref (gst_ca);
      return GST_FLOW_ERROR;
    }
  }

  GstD3D12FenceData *fence_data;
  gst_d3d12_fence_data_pool_acquire (priv->fence_data_pool, &fence_data);
  gst_d3d12_fence_data_push (fence_data, FENCE_NOTIFY_MINI_OBJECT (gst_ca));

  auto cq = gst_d3d12_device_get_cmd_queue (priv->ctx->device,
      D3D12_COMMAND_LIST_TYPE_DIRECT);
  auto fence = gst_d3d12_cmd_queue_get_fence_handle (cq);
  if (!gst_d3d12_converter_convert_buffer (priv->ctx->conv,
          inbuf, outbuf, fence_data, priv->ctx->cl.Get (), TRUE)) {
    GST_ERROR_OBJECT (self, "Couldn't build command list");
    gst_d3d12_fence_data_unref (fence_data);
    return GST_FLOW_ERROR;
  }

  auto dmem = (GstD3D12Memory *) gst_buffer_peek_memory (outbuf, 0);
  auto tex = gst_d3d12_memory_get_resource_handle (dmem);

  D3D12_RESOURCE_BARRIER barrier = CD3DX12_RESOURCE_BARRIER::Transition
      (tex, D3D12_RESOURCE_STATE_RENDER_TARGET,
      D3D12_RESOURCE_STATE_NON_PIXEL_SHADER_RESOURCE, 0);
  priv->ctx->cl->ResourceBarrier (1, &barrier);

  if (!gst_d3d12_mip_gen_execute (priv->ctx->gen, tex, fence_data,
          priv->ctx->cl.Get ())) {
    GST_ERROR_OBJECT (self, "Couldn't build mip gen command");
    gst_d3d12_fence_data_unref (fence_data);
    return GST_FLOW_ERROR;
  }

  hr = priv->ctx->cl->Close ();
  if (!gst_d3d12_result (hr, priv->ctx->device)) {
    GST_ERROR_OBJECT (self, "Couldn't close command list");
    gst_d3d12_fence_data_unref (fence_data);
    return GST_FLOW_ERROR;
  }

  ID3D12CommandList *cmd_list[] = { priv->ctx->cl.Get () };

  hr = gst_d3d12_cmd_queue_execute_command_lists (cq,
      1, cmd_list, &priv->ctx->fence_val);
  if (!gst_d3d12_result (hr, priv->ctx->device)) {
    GST_ERROR_OBJECT (self, "Couldn't execute command list");
    gst_d3d12_fence_data_unref (fence_data);
    return GST_FLOW_ERROR;
  }

  gst_d3d12_buffer_set_fence (outbuf, fence, priv->ctx->fence_val, FALSE);
  gst_d3d12_cmd_queue_set_notify (cq, priv->ctx->fence_val,
      FENCE_NOTIFY_MINI_OBJECT (fence_data));

  priv->ctx->scheduled.push (priv->ctx->fence_val);

  auto completed = gst_d3d12_device_get_completed_value (priv->ctx->device,
      D3D12_COMMAND_LIST_TYPE_DIRECT);
  while (!priv->ctx->scheduled.empty ()) {
    if (priv->ctx->scheduled.front () > completed)
      break;

    priv->ctx->scheduled.pop ();
  }

  auto async_depth = priv->async_depth.load ();
  if (async_depth > 0 && priv->ctx->scheduled.size () > async_depth) {
    auto fence_to_wait = priv->ctx->scheduled.front ();
    priv->ctx->scheduled.pop ();
    gst_d3d12_device_fence_wait (priv->ctx->device,
        D3D12_COMMAND_LIST_TYPE_DIRECT, fence_to_wait);
  }

  return GST_FLOW_OK;
}