/* GStreamer
 * Copyright (C) 2021 Igalia, S.L.
 *     Author: Víctor Jáquez <vjaquez@igalia.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 "gstvabasetransform.h"

#include <gst/va/gstva.h>
#include <gst/va/gstvavideoformat.h>
#include <gst/va/vasurfaceimage.h>

#include "gstvabase.h"
#include "gstvacaps.h"
#include "gstvapluginutils.h"

#define GST_CAT_DEFAULT gst_va_base_transform_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);

enum
{
  PROP_DEVICE_PATH = 1,
  N_PROPERTIES
};

static GParamSpec *properties[N_PROPERTIES];

#define META_TAG_COLORSPACE meta_tag_colorspace_quark
static GQuark meta_tag_colorspace_quark;
#define META_TAG_SIZE meta_tag_size_quark
static GQuark meta_tag_size_quark;
#define META_TAG_ORIENTATION meta_tag_orientation_quark
static GQuark meta_tag_orientation_quark;
#define META_TAG_VIDEO meta_tag_video_quark
static GQuark meta_tag_video_quark;

struct _GstVaBaseTransformPrivate
{
  GstVideoInfo srcpad_info;

  GstBufferPool *other_pool;

  GstCaps *sinkpad_caps;
  GstVideoInfo sinkpad_info;
  GstBufferPool *sinkpad_pool;
  guint uncropped_width;
  guint uncropped_height;

  GstCaps *filter_caps;
};

/**
 * GstVaBaseTransform:
 *
 * A base class implementation for VA-API filters.
 *
 * Since: 1.20
 */
#define gst_va_base_transform_parent_class parent_class
G_DEFINE_ABSTRACT_TYPE_WITH_CODE (GstVaBaseTransform, gst_va_base_transform,
    GST_TYPE_BASE_TRANSFORM, G_ADD_PRIVATE (GstVaBaseTransform)
    GST_DEBUG_CATEGORY_INIT (gst_va_base_transform_debug,
        "vabasetransform", 0, "vabasetransform element");
    );

static void
gst_va_base_transform_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstVaBaseTransform *self = GST_VA_BASE_TRANSFORM (object);
  GstVaBaseTransformClass *klass = GST_VA_BASE_TRANSFORM_GET_CLASS (self);

  switch (prop_id) {
    case PROP_DEVICE_PATH:{
      if (!self->display)
        g_value_set_string (value, klass->render_device_path);
      else if (GST_IS_VA_DISPLAY_PLATFORM (self->display))
        g_object_get_property (G_OBJECT (self->display), "path", value);
      else
        g_value_set_string (value, NULL);

      break;
    }
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
  }
}

static void
gst_va_base_transform_dispose (GObject * object)
{
  GstVaBaseTransform *self = GST_VA_BASE_TRANSFORM (object);

  if (self->priv->other_pool) {
    gst_buffer_pool_set_active (self->priv->other_pool, FALSE);
    gst_clear_object (&self->priv->other_pool);
  }

  gst_clear_caps (&self->out_caps);
  gst_clear_caps (&self->in_caps);

  gst_clear_caps (&self->priv->filter_caps);

  gst_clear_object (&self->filter);
  gst_clear_object (&self->display);

  if (self->priv->sinkpad_pool) {
    gst_buffer_pool_set_active (self->priv->sinkpad_pool, FALSE);
    gst_clear_object (&self->priv->sinkpad_pool);
  }

  gst_clear_caps (&self->priv->sinkpad_caps);

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

static void
gst_va_base_transform_init (GstVaBaseTransform * self)
{
  gst_base_transform_set_qos_enabled (GST_BASE_TRANSFORM (self), TRUE);

  self->priv = gst_va_base_transform_get_instance_private (self);
}

static gboolean
gst_va_base_transform_query (GstBaseTransform * trans,
    GstPadDirection direction, GstQuery * query)
{
  GstVaBaseTransform *self = GST_VA_BASE_TRANSFORM (trans);
  gboolean ret = FALSE;

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_CONTEXT:
    {
      GstVaDisplay *display = NULL;

      gst_object_replace ((GstObject **) & display,
          (GstObject *) self->display);
      ret = gst_va_handle_context_query (GST_ELEMENT_CAST (self), query,
          display);
      gst_clear_object (&display);
      break;
    }
    default:
      ret = GST_BASE_TRANSFORM_CLASS (parent_class)->query (trans, direction,
          query);
      break;
  }

  return ret;
}

static gboolean
gst_va_base_transform_set_caps (GstBaseTransform * trans, GstCaps * incaps,
    GstCaps * outcaps)
{
  GstVaBaseTransform *self = GST_VA_BASE_TRANSFORM (trans);
  GstVaBaseTransformClass *fclass;
  GstVideoInfo in_info, out_info;
  gboolean res;

  /* input caps */
  if (!gst_video_is_dma_drm_caps (incaps)) {
    gst_video_info_dma_drm_init (&self->in_drm_info);
    if (!gst_video_info_from_caps (&in_info, incaps))
      goto invalid_caps;
  } else {
    if (!gst_video_info_dma_drm_from_caps (&self->in_drm_info, incaps))
      goto invalid_caps;
    if (!gst_va_dma_drm_info_to_video_info (&self->in_drm_info, &in_info))
      goto invalid_caps;
  }

  /* output caps */
  if (!gst_va_video_info_from_caps (&out_info, NULL, outcaps))
    goto invalid_caps;

  fclass = GST_VA_BASE_TRANSFORM_GET_CLASS (self);
  if (fclass->set_info)
    res = fclass->set_info (self, incaps, &in_info, outcaps, &out_info);
  else
    res = TRUE;

  self->negotiated = res;

  if (res) {
    gst_caps_replace (&self->in_caps, incaps);
    gst_caps_replace (&self->out_caps, outcaps);

    self->in_info = in_info;
    self->out_info = out_info;
  }

  if (self->priv->sinkpad_pool) {
    gst_buffer_pool_set_active (self->priv->sinkpad_pool, FALSE);
    gst_clear_object (&self->priv->sinkpad_pool);
  }

  if (self->priv->other_pool) {
    gst_buffer_pool_set_active (self->priv->other_pool, FALSE);
    gst_clear_object (&self->priv->other_pool);
  }

  return res;

  /* ERRORS */
invalid_caps:
  {
    GST_ERROR_OBJECT (self, "invalid caps");
    self->negotiated = FALSE;
    return FALSE;
  }
}

/* Answer upstream allocation query. */
static gboolean
gst_va_base_transform_propose_allocation (GstBaseTransform * trans,
    GstQuery * decide_query, GstQuery * query)
{
  GstVaBaseTransform *self = GST_VA_BASE_TRANSFORM (trans);
  GstAllocator *allocator = NULL;
  GstAllocationParams params = { 0, };
  GstBufferPool *pool;
  GstCaps *caps;
  gboolean update_allocator = FALSE;
  guint size, usage_hint;

  gst_clear_caps (&self->priv->sinkpad_caps);

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

  /* passthrough, we're done */
  if (!decide_query)
    return TRUE;

  if (gst_query_get_n_allocation_pools (query) > 0)
    return TRUE;

  gst_query_parse_allocation (query, &caps, NULL);
  if (!caps)
    return FALSE;

  usage_hint = va_get_surface_usage_hint (self->display,
      VAEntrypointVideoProc, GST_PAD_SINK, gst_video_is_dma_drm_caps (caps));

  if (gst_query_get_n_allocation_params (query) > 0) {
    gst_query_parse_nth_allocation_param (query, 0, &allocator, &params);
    if (!GST_IS_VA_DMABUF_ALLOCATOR (allocator)
        && !GST_IS_VA_ALLOCATOR (allocator))
      gst_clear_object (&allocator);
    update_allocator = TRUE;
  } else {
    gst_allocation_params_init (&params);
  }

  if (!allocator) {
    if (!(allocator = gst_va_base_transform_allocator_from_caps (self, caps)))
      return FALSE;
  }

  pool = gst_va_pool_new_with_config (caps, 1 + self->extra_min_buffers, 0,
      usage_hint, GST_VA_FEATURE_AUTO, allocator, &params);
  if (!pool) {
    gst_object_unref (allocator);
    goto config_failed;
  }

  if (update_allocator)
    gst_query_set_nth_allocation_param (query, 0, allocator, &params);
  else
    gst_query_add_allocation_param (query, allocator, &params);

  if (!gst_va_pool_get_buffer_size (pool, &size))
    goto config_failed;

  gst_query_add_allocation_pool (query, pool, size, 1 + self->extra_min_buffers,
      0);

  GST_DEBUG_OBJECT (self,
      "proposing %" GST_PTR_FORMAT " with allocator %" GST_PTR_FORMAT,
      pool, allocator);

  gst_object_unref (allocator);
  gst_object_unref (pool);

  gst_query_add_allocation_meta (query, GST_VIDEO_META_API_TYPE, NULL);

  self->priv->sinkpad_caps = gst_caps_ref (caps);

  return TRUE;

  /* ERRORS */
config_failed:
  {
    GST_ERROR_OBJECT (self, "failed to set config");
    return FALSE;
  }
}

/* configure the allocation query that was answered downstream, we can
 * configure some properties on it. Only it's called when not in
 * passthrough mode. */
static gboolean
gst_va_base_transform_decide_allocation (GstBaseTransform * trans,
    GstQuery * query)
{
  GstVaBaseTransform *self = GST_VA_BASE_TRANSFORM (trans);
  GstAllocator *allocator = NULL, *other_allocator = NULL;
  GstAllocationParams params, other_params;
  GstBufferPool *pool = NULL, *other_pool = NULL;
  GstCaps *outcaps = NULL;
  GstStructure *config;
  guint min, max, other_size = 0, size = 0, usage_hint;
  gboolean update_pool, update_allocator, has_videometa, copy_frames;
  gboolean dont_use_other_pool = FALSE;

  gst_query_parse_allocation (query, &outcaps, NULL);
  if (!outcaps)
    return FALSE;

  if (gst_query_get_n_allocation_params (query) > 0) {
    GstVaDisplay *display;

    gst_query_parse_nth_allocation_param (query, 0, &allocator, &other_params);
    display = gst_va_allocator_peek_display (allocator);
    if (!display) {
      /* save the allocator for the other pool */
      other_allocator = allocator;
      allocator = NULL;
    } else if (display != self->display) {
      /* The allocator and pool belong to other display, we should not use. */
      gst_clear_object (&allocator);
      dont_use_other_pool = TRUE;
    }

    update_allocator = TRUE;
  } else {
    update_allocator = FALSE;
  }

  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_VA_POOL (pool)) {
        GST_DEBUG_OBJECT (self,
            "may need other pool for copy frames %" GST_PTR_FORMAT, pool);
        other_pool = pool;
        pool = NULL;
        other_size = size;
      } else if (dont_use_other_pool) {
        gst_clear_object (&pool);
      }
    }

    update_pool = TRUE;
  } else {
    min = 1;
    max = 0;
    update_pool = FALSE;
  }

  if (!allocator) {
    if (!(allocator =
            gst_va_base_transform_allocator_from_caps (self, outcaps)))
      goto bail;
  }

  if (!pool)
    pool = gst_va_pool_new ();

  usage_hint = va_get_surface_usage_hint (self->display,
      VAEntrypointVideoProc, GST_PAD_SRC, gst_video_is_dma_drm_caps (outcaps));

  config = gst_buffer_pool_get_config (pool);
  gst_buffer_pool_config_set_allocator (config, allocator, &params);
  gst_buffer_pool_config_add_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META);
  gst_buffer_pool_config_set_params (config, outcaps, 0, min, max);
  gst_buffer_pool_config_set_va_allocation_params (config, usage_hint,
      GST_VA_FEATURE_AUTO);
  if (!gst_buffer_pool_set_config (pool, config))
    goto bail;
  if (!gst_va_pool_get_buffer_size (pool, &size))
    goto bail;

  if (GST_IS_VA_DMABUF_ALLOCATOR (allocator)) {
    GstVideoInfoDmaDrm dma_info;

    gst_va_dmabuf_allocator_get_format (allocator, &dma_info, NULL);
    self->priv->srcpad_info = dma_info.vinfo;
  } else if (GST_IS_VA_ALLOCATOR (allocator)) {
    gst_va_allocator_get_format (allocator, &self->priv->srcpad_info, NULL,
        NULL);
  }

  if (update_allocator)
    gst_query_set_nth_allocation_param (query, 0, allocator, &params);
  else
    gst_query_add_allocation_param (query, allocator, &params);

  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);

  has_videometa = gst_query_find_allocation_meta (query,
      GST_VIDEO_META_API_TYPE, NULL);

  copy_frames = (!has_videometa && gst_va_pool_requires_video_meta (pool)
      && gst_caps_is_raw (outcaps));
  if (copy_frames) {
    if (other_pool) {
      gst_object_replace ((GstObject **) & self->priv->other_pool,
          (GstObject *) other_pool);
    } else {
      gst_clear_object (&self->priv->other_pool);
      self->priv->other_pool =
          gst_va_create_other_pool (other_allocator, &other_params, outcaps,
          other_size);
    }
    if (!self->priv->other_pool)
      goto bail;
    GST_DEBUG_OBJECT (self, "Use the other pool for copy %" GST_PTR_FORMAT,
        self->priv->other_pool);
  } else {
    gst_clear_object (&self->priv->other_pool);
  }

  GST_DEBUG_OBJECT (self,
      "decided pool %" GST_PTR_FORMAT " with allocator %" GST_PTR_FORMAT,
      pool, allocator);

  gst_object_unref (allocator);
  gst_object_unref (pool);
  gst_clear_object (&other_allocator);
  gst_clear_object (&other_pool);

  /* removes allocation metas */
  return GST_BASE_TRANSFORM_CLASS (parent_class)->decide_allocation (trans,
      query);

bail:
  gst_object_unref (allocator);
  gst_object_unref (pool);
  gst_clear_object (&other_allocator);
  gst_clear_object (&other_pool);

  return FALSE;
}

/* output buffers must be from our VA-based pool, they cannot be
 * system-allocated */
static gboolean
gst_va_base_transform_transform_size (GstBaseTransform * trans,
    GstPadDirection direction, GstCaps * caps, gsize size,
    GstCaps * othercaps, gsize * othersize)
{
  return FALSE;
}

static GstFlowReturn
gst_va_base_transform_generate_output (GstBaseTransform * trans,
    GstBuffer ** outbuf)
{
  GstVaBaseTransform *self = GST_VA_BASE_TRANSFORM (trans);
  GstVideoFrame src_frame;
  GstVideoFrame dest_frame;
  GstBuffer *buffer = NULL;
  GstFlowReturn ret;

  ret = GST_BASE_TRANSFORM_CLASS (parent_class)->generate_output (trans,
      outbuf);

  if (ret != GST_FLOW_OK || *outbuf == NULL)
    return ret;

  if (!self->priv->other_pool)
    return GST_FLOW_OK;

  /* Now need to copy the output buffer */
  ret = GST_FLOW_ERROR;

  if (!gst_buffer_pool_set_active (self->priv->other_pool, TRUE)) {
    GST_WARNING_OBJECT (self, "failed to active the other pool %"
        GST_PTR_FORMAT, self->priv->other_pool);
    goto out;
  }

  ret = gst_buffer_pool_acquire_buffer (self->priv->other_pool, &buffer, NULL);
  if (ret != GST_FLOW_OK)
    goto out;

  if (!gst_video_frame_map (&src_frame, &self->priv->srcpad_info, *outbuf,
          GST_MAP_READ))
    goto out;

  if (!gst_video_frame_map (&dest_frame, &self->out_info, buffer,
          GST_MAP_WRITE)) {
    gst_video_frame_unmap (&src_frame);
    goto out;
  }

  if (!gst_video_frame_copy (&dest_frame, &src_frame)) {
    gst_video_frame_unmap (&src_frame);
    gst_video_frame_unmap (&dest_frame);
    goto out;
  }

  gst_video_frame_unmap (&src_frame);
  gst_video_frame_unmap (&dest_frame);

  gst_buffer_replace (outbuf, buffer);
  ret = GST_FLOW_OK;

out:
  gst_clear_buffer (&buffer);
  return ret;
}

static GstStateChangeReturn
gst_va_base_transform_change_state (GstElement * element,
    GstStateChange transition)
{
  GstVaBaseTransform *self = GST_VA_BASE_TRANSFORM (element);
  GstVaBaseTransformClass *klass = GST_VA_BASE_TRANSFORM_GET_CLASS (element);
  GstStateChangeReturn ret;

  switch (transition) {
    case GST_STATE_CHANGE_NULL_TO_READY:
      if (!gst_va_ensure_element_data (element, klass->render_device_path,
              &self->display))
        goto open_failed;
      g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_DEVICE_PATH]);
      gst_clear_caps (&self->priv->filter_caps);
      gst_clear_object (&self->filter);
      self->filter = gst_va_filter_new (self->display);
      if (!gst_va_filter_open (self->filter))
        goto open_failed;
      if (klass->update_properties)
        klass->update_properties (self);
      break;
    default:
      break;
  }

  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);

  switch (transition) {
    case GST_STATE_CHANGE_PAUSED_TO_READY:
      gst_va_filter_close (self->filter);
      break;
    case GST_STATE_CHANGE_READY_TO_NULL:
      gst_clear_caps (&self->priv->filter_caps);
      gst_clear_object (&self->filter);
      gst_clear_object (&self->display);
      g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_DEVICE_PATH]);
      break;
    default:
      break;
  }

  return ret;

  /* Errors */
open_failed:
  {
    GST_ELEMENT_ERROR (self, LIBRARY, INIT, (NULL), ("Failed to open VPP"));
    return GST_STATE_CHANGE_FAILURE;
  }
}

static void
gst_va_base_transform_set_context (GstElement * element, GstContext * context)
{
  GstVaDisplay *old_display, *new_display;
  GstVaBaseTransform *self = GST_VA_BASE_TRANSFORM (element);
  GstVaBaseTransformClass *klass = GST_VA_BASE_TRANSFORM_GET_CLASS (self);
  gboolean ret;

  old_display = self->display ? gst_object_ref (self->display) : NULL;
  ret = gst_va_handle_set_context (element, context, klass->render_device_path,
      &self->display);
  new_display = self->display ? gst_object_ref (self->display) : NULL;

  if (!ret
      || (old_display && new_display && old_display != new_display
          && self->filter)) {
    GST_ELEMENT_WARNING (element, RESOURCE, BUSY,
        ("Can't replace VA display while operating"), (NULL));
  }

  gst_clear_object (&old_display);
  gst_clear_object (&new_display);

  GST_ELEMENT_CLASS (parent_class)->set_context (element, context);
}

static void
gst_va_base_transform_class_init (GstVaBaseTransformClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *element_class;
  GstBaseTransformClass *trans_class;

#define D(type) \
  G_PASTE (META_TAG_, type) = \
    g_quark_from_static_string (G_PASTE (G_PASTE (GST_META_TAG_VIDEO_, type), _STR))
  D (COLORSPACE);
  D (SIZE);
  D (ORIENTATION);
#undef D
  META_TAG_VIDEO = g_quark_from_static_string (GST_META_TAG_VIDEO_STR);

  gobject_class = G_OBJECT_CLASS (klass);
  element_class = GST_ELEMENT_CLASS (klass);
  trans_class = GST_BASE_TRANSFORM_CLASS (klass);

  gobject_class->dispose = gst_va_base_transform_dispose;
  gobject_class->get_property = gst_va_base_transform_get_property;

  trans_class->query = GST_DEBUG_FUNCPTR (gst_va_base_transform_query);
  trans_class->set_caps = GST_DEBUG_FUNCPTR (gst_va_base_transform_set_caps);
  trans_class->propose_allocation =
      GST_DEBUG_FUNCPTR (gst_va_base_transform_propose_allocation);
  trans_class->decide_allocation =
      GST_DEBUG_FUNCPTR (gst_va_base_transform_decide_allocation);
  trans_class->transform_size =
      GST_DEBUG_FUNCPTR (gst_va_base_transform_transform_size);
  trans_class->generate_output =
      GST_DEBUG_FUNCPTR (gst_va_base_transform_generate_output);

  element_class->set_context =
      GST_DEBUG_FUNCPTR (gst_va_base_transform_set_context);
  element_class->change_state =
      GST_DEBUG_FUNCPTR (gst_va_base_transform_change_state);

  /**
   * GstVaBaseTransform:device-path:
   *
   * It shows the DRM device path used for the VA operation, if any.
   *
   * Since: 1.22
   */
  properties[PROP_DEVICE_PATH] = g_param_spec_string ("device-path",
      "Device Path", GST_VA_DEVICE_PATH_PROP_DESC, NULL,
      GST_PARAM_DOC_SHOW_DEFAULT | G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);

  g_object_class_install_properties (gobject_class, N_PROPERTIES, properties);

  gst_type_mark_as_plugin_api (GST_TYPE_VA_BASE_TRANSFORM, 0);
}

GstAllocator *
gst_va_base_transform_allocator_from_caps (GstVaBaseTransform * self,
    GstCaps * caps)
{
  GstAllocator *allocator = NULL;

  if (gst_caps_is_dmabuf (caps)) {
    allocator = gst_va_dmabuf_allocator_new (self->display);
  } else {
    GArray *surface_formats = gst_va_filter_get_surface_formats (self->filter);
    allocator = gst_va_allocator_new (self->display, surface_formats);
  }

  return allocator;
}

static gboolean
_check_uncropped_size (GstVaBaseTransform * self, GstBuffer * inbuf)
{
  GstVideoCropMeta *crop_meta;
  GstVideoMeta *video_meta;

  crop_meta = gst_buffer_get_video_crop_meta (inbuf);
  video_meta = gst_buffer_get_video_meta (inbuf);

  if (!crop_meta) {
    if (self->priv->uncropped_width > 0 || self->priv->uncropped_height > 0) {
      self->priv->uncropped_width = 0;
      self->priv->uncropped_height = 0;
      return TRUE;
    }

    return FALSE;
  }

  if (!video_meta) {
    GST_WARNING_OBJECT (self, "The buffer has video crop meta without "
        "video meta, the cropped result may be wrong.");
    self->priv->uncropped_width = 0;
    self->priv->uncropped_height = 0;
    return FALSE;
  }

  if (video_meta->width < crop_meta->x + crop_meta->width ||
      video_meta->height < crop_meta->y + crop_meta->height) {
    GST_WARNING_OBJECT (self, "Invalid video meta or crop meta, "
        "the cropped result may be wrong.");
    self->priv->uncropped_width = 0;
    self->priv->uncropped_height = 0;
    return FALSE;
  }

  if (self->priv->uncropped_width != video_meta->width ||
      self->priv->uncropped_height != video_meta->height) {
    self->priv->uncropped_width = video_meta->width;
    self->priv->uncropped_height = video_meta->height;
    return TRUE;
  }

  return FALSE;
}

static GstBufferPool *
_get_sinkpad_pool (GstElement * element, gpointer data)
{
  GstVaBaseTransform *self = GST_VA_BASE_TRANSFORM (element);
  GstAllocator *allocator;
  GstAllocationParams params = { 0, };
  GstCaps *caps;
  guint usage_hint;

  if (self->priv->sinkpad_pool)
    return self->priv->sinkpad_pool;

  if (self->priv->sinkpad_caps)
    caps = gst_caps_copy (self->priv->sinkpad_caps);
  else
    caps = gst_caps_copy (self->in_caps);

  if (!gst_va_base_convert_caps_to_va (caps)) {
    GST_ERROR_OBJECT (self, "Invalid caps %" GST_PTR_FORMAT, caps);
    gst_caps_unref (caps);
    return NULL;
  }

  /* When the input buffer contains video crop meta, the real video
     resolution can be bigger than the caps. The video meta should
     contain the real video resolution. */
  if (self->priv->uncropped_width > 0)
    gst_caps_set_simple (caps, "width", G_TYPE_INT,
        self->priv->uncropped_width, NULL);
  if (self->priv->uncropped_height > 0)
    gst_caps_set_simple (caps, "height", G_TYPE_INT,
        self->priv->uncropped_height, NULL);

  usage_hint = va_get_surface_usage_hint (self->display,
      VAEntrypointVideoProc, GST_PAD_SINK, FALSE);

  allocator = gst_va_base_transform_allocator_from_caps (self, caps);
  g_assert (GST_IS_VA_ALLOCATOR (allocator));

  self->priv->sinkpad_pool = gst_va_pool_new_with_config (caps, 1, 0,
      usage_hint, GST_VA_FEATURE_AUTO, allocator, &params);
  if (!self->priv->sinkpad_pool) {
    gst_caps_unref (caps);
    gst_object_unref (allocator);
    return NULL;
  }

  gst_va_allocator_get_format (allocator, &self->priv->sinkpad_info,
      NULL, NULL);

  gst_object_unref (allocator);
  gst_caps_unref (caps);

  if (!gst_buffer_pool_set_active (self->priv->sinkpad_pool, TRUE)) {
    GST_WARNING_OBJECT (self, "failed to active the sinkpad pool %"
        GST_PTR_FORMAT, self->priv->sinkpad_pool);
    return NULL;
  }

  return self->priv->sinkpad_pool;
}

typedef struct
{
  GstVaBaseTransform *self;
  GstBuffer *outbuf;
} CopyMetaData;

static gboolean
foreach_metadata (GstBuffer * inbuf, GstMeta ** meta, gpointer user_data)
{
  CopyMetaData *data = user_data;
  GstVaBaseTransform *self = data->self;
  GstBuffer *outbuf = data->outbuf;
  const GstMetaInfo *info = (*meta)->info;
  gboolean do_copy = FALSE;

  if (gst_meta_api_type_has_tag (info->api, META_TAG_COLORSPACE)
      || gst_meta_api_type_has_tag (info->api, META_TAG_SIZE)
      || gst_meta_api_type_has_tag (info->api, META_TAG_ORIENTATION)
      || gst_meta_api_type_has_tag (info->api, META_TAG_VIDEO)) {
    do_copy = TRUE;
  }

  if (do_copy) {
    GstMetaTransformCopy copy_data = { FALSE, 0, -1 };
    /* simply copy then */
    if (info->transform_func) {
      GST_DEBUG_OBJECT (self, "copy metadata %s", g_type_name (info->api));
      info->transform_func (outbuf, *meta, inbuf,
          _gst_meta_transform_copy, &copy_data);
    } else {
      GST_DEBUG_OBJECT (self, "couldn't copy metadata %s",
          g_type_name (info->api));
    }
  }
  return TRUE;
}

GstFlowReturn
gst_va_base_transform_import_buffer (GstVaBaseTransform * self,
    GstBuffer * inbuf, GstBuffer ** buf)
{
  GstVaBufferImporter importer = {
    .element = GST_ELEMENT_CAST (self),
#ifndef GST_DISABLE_GST_DEBUG
    .debug_category = GST_CAT_DEFAULT,
#endif
    .display = self->display,
    .entrypoint = VAEntrypointVideoProc,
    .in_drm_info = &self->in_drm_info,
    .sinkpad_info = &self->priv->sinkpad_info,
    .get_sinkpad_pool = _get_sinkpad_pool,
  };
  GstFlowReturn ret;
  CopyMetaData data;

  g_return_val_if_fail (GST_IS_VA_BASE_TRANSFORM (self), GST_FLOW_ERROR);

  if (_check_uncropped_size (self, inbuf)) {
    if (self->priv->sinkpad_pool)
      gst_buffer_pool_set_active (self->priv->sinkpad_pool, FALSE);

    gst_clear_object (&self->priv->sinkpad_pool);
  }

  ret = gst_va_buffer_importer_import (&importer, inbuf, buf);
  if (ret != GST_FLOW_OK)
    goto bail;

  if (*buf == inbuf)
    goto bail;

  data.self = self;
  data.outbuf = *buf;

  gst_buffer_foreach_meta (inbuf, foreach_metadata, &data);

bail:
  return ret;
}

GstCaps *
gst_va_base_transform_get_filter_caps (GstVaBaseTransform * self)
{
  g_return_val_if_fail (GST_IS_VA_BASE_TRANSFORM (self), NULL);

  GST_OBJECT_LOCK (self);
  if (self->priv->filter_caps) {
    GST_OBJECT_UNLOCK (self);
    return self->priv->filter_caps;
  }
  GST_OBJECT_UNLOCK (self);

  if (!self->filter)
    return NULL;

  GST_OBJECT_LOCK (self);
  self->priv->filter_caps = gst_va_filter_get_caps (self->filter);
  GST_OBJECT_UNLOCK (self);
  return self->priv->filter_caps;
}