gstreamer/subprojects/gstreamer-vaapi/gst/vaapi/gstvaapiencode.c

/*
 *  gstvaapiencode.c - VA-API video encoder
 *
 *  Copyright (C) 2013-2014 Intel Corporation
 *    Author: Wind Yuan <feng.yuan@intel.com>
 *    Author: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2.1
 *  of the License, or (at your option) any later version.
 *
 *  This 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301 USA
 */

#include "gstcompat.h"
#include <gst/vaapi/gstvaapivalue.h>
#include <gst/vaapi/gstvaapidisplay.h>
#include <gst/vaapi/gstvaapiprofilecaps.h>
#include "gstvaapiencode.h"
#include "gstvaapipluginutil.h"
#include "gstvaapivideometa.h"
#include "gstvaapivideomemory.h"
#include "gstvaapivideobufferpool.h"

#define GST_PLUGIN_NAME "vaapiencode"
#define GST_PLUGIN_DESC "A VA-API based video encoder"

#define GST_VAAPI_ENCODE_FLOW_TIMEOUT           GST_FLOW_CUSTOM_SUCCESS
#define GST_VAAPI_ENCODE_FLOW_MEM_ERROR         GST_FLOW_CUSTOM_ERROR
#define GST_VAAPI_ENCODE_FLOW_CONVERT_ERROR     GST_FLOW_CUSTOM_ERROR_1

GST_DEBUG_CATEGORY_STATIC (gst_vaapiencode_debug);
#ifndef GST_DISABLE_GST_DEBUG
#define GST_CAT_DEFAULT gst_vaapiencode_debug
#else
#define GST_CAT_DEFAULT NULL
#endif

G_DEFINE_ABSTRACT_TYPE_WITH_CODE (GstVaapiEncode,
    gst_vaapiencode, GST_TYPE_VIDEO_ENCODER,
    GST_VAAPI_PLUGIN_BASE_INIT_INTERFACES);

GST_VAAPI_PLUGIN_BASE_DEFINE_SET_CONTEXT (gst_vaapiencode_parent_class);

enum
{
  PROP_0,

  PROP_BASE,
};

static inline gboolean
ensure_display (GstVaapiEncode * encode)
{
  return gst_vaapi_plugin_base_ensure_display (GST_VAAPI_PLUGIN_BASE (encode));
}

static gboolean
gst_vaapiencode_sink_query (GstVideoEncoder * encoder, GstQuery * query)
{
  gboolean ret = TRUE;
  GstElement *const element = GST_ELEMENT (encoder);

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_CONTEXT:
      ret = gst_vaapi_handle_context_query (element, query);
      break;
    default:
      ret = GST_VIDEO_ENCODER_CLASS (gst_vaapiencode_parent_class)->sink_query
          (encoder, query);
      break;
  }

  return ret;
}

static gboolean
gst_vaapiencode_src_query (GstVideoEncoder * encoder, GstQuery * query)
{
  gboolean ret = TRUE;
  GstElement *const element = GST_ELEMENT (encoder);

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_CONTEXT:
      ret = gst_vaapi_handle_context_query (element, query);
      break;
    default:
      ret = GST_VIDEO_ENCODER_CLASS (gst_vaapiencode_parent_class)->src_query
          (encoder, query);
      break;
  }

  return ret;
}

typedef struct
{
  guint id;
  GParamSpec *pspec;
  GValue value;
} PropValue;

static void
prop_value_free (PropValue * prop_value)
{
  if (!prop_value)
    return;

  if (G_VALUE_TYPE (&prop_value->value))
    g_value_unset (&prop_value->value);

  if (prop_value->pspec) {
    g_param_spec_unref (prop_value->pspec);
    prop_value->pspec = NULL;
  }
  g_slice_free (PropValue, prop_value);
}

static PropValue *
prop_value_new_entry (guint id, GParamSpec * pspec, const GValue * value)
{
  PropValue *prop_value;

  if (!pspec)
    return NULL;

  prop_value = g_slice_new0 (PropValue);
  if (!prop_value)
    return NULL;

  prop_value->id = id;
  prop_value->pspec = g_param_spec_ref (pspec);
  g_value_init (&prop_value->value, pspec->value_type);

  g_assert (g_value_type_compatible (pspec->value_type, G_VALUE_TYPE (value)));
  g_value_copy (value, &prop_value->value);

  return prop_value;
}

static inline PropValue *
prop_value_lookup_entry (GPtrArray * prop_values, guint prop_id)
{
  guint i;
  PropValue *prop_value;

  if (prop_values == NULL)
    return NULL;

  for (i = 0; i < prop_values->len; i++) {
    prop_value = g_ptr_array_index (prop_values, i);
    if (prop_value->id == prop_id)
      return prop_value;
  }

  return NULL;
}

static GstFlowReturn
gst_vaapiencode_default_alloc_buffer (GstVaapiEncode * encode,
    GstVaapiCodedBuffer * coded_buf, GstBuffer ** outbuf_ptr)
{
  GstBuffer *buf;
  gint32 buf_size;

  g_return_val_if_fail (coded_buf != NULL, GST_FLOW_ERROR);
  g_return_val_if_fail (outbuf_ptr != NULL, GST_FLOW_ERROR);

  buf_size = gst_vaapi_coded_buffer_get_size (coded_buf);
  if (buf_size <= 0)
    goto error_invalid_buffer;

  buf =
      gst_video_encoder_allocate_output_buffer (GST_VIDEO_ENCODER_CAST (encode),
      buf_size);
  if (!buf)
    goto error_create_buffer;
  if (!gst_vaapi_coded_buffer_copy_into (buf, coded_buf))
    goto error_copy_buffer;

  *outbuf_ptr = buf;
  return GST_FLOW_OK;

  /* ERRORS */
error_invalid_buffer:
  {
    GST_ERROR ("invalid GstVaapiCodedBuffer size (%d bytes)", buf_size);
    return GST_VAAPI_ENCODE_FLOW_MEM_ERROR;
  }
error_create_buffer:
  {
    GST_ERROR ("failed to create output buffer of size %d", buf_size);
    return GST_VAAPI_ENCODE_FLOW_MEM_ERROR;
  }
error_copy_buffer:
  {
    GST_ERROR ("failed to copy GstVaapiCodedBuffer data");
    gst_buffer_unref (buf);
    return GST_VAAPI_ENCODE_FLOW_MEM_ERROR;
  }
}

static gboolean
ensure_output_state (GstVaapiEncode * encode)
{
  GstVideoEncoder *const venc = GST_VIDEO_ENCODER_CAST (encode);
  GstVaapiEncodeClass *const klass = GST_VAAPIENCODE_GET_CLASS (encode);
  GstVaapiEncoderStatus status;
  GstCaps *out_caps;

  if (!encode->input_state_changed)
    return TRUE;

  out_caps = klass->get_caps (encode);
  if (!out_caps)
    return FALSE;

  if (encode->output_state)
    gst_video_codec_state_unref (encode->output_state);
  encode->output_state = gst_video_encoder_set_output_state (venc, out_caps,
      encode->input_state);

  if (encode->need_codec_data) {
    status = gst_vaapi_encoder_get_codec_data (encode->encoder,
        &encode->output_state->codec_data);
    if (status != GST_VAAPI_ENCODER_STATUS_SUCCESS)
      return FALSE;
  }

  if (!gst_video_encoder_negotiate (venc))
    return FALSE;

  encode->input_state_changed = FALSE;
  return TRUE;
}

static GstFlowReturn
gst_vaapiencode_push_frame (GstVaapiEncode * encode, gint64 timeout)
{
  GstVideoEncoder *const venc = GST_VIDEO_ENCODER_CAST (encode);
  GstVaapiEncodeClass *const klass = GST_VAAPIENCODE_GET_CLASS (encode);
  GstVideoCodecFrame *out_frame;
  GstVaapiCodedBufferProxy *codedbuf_proxy = NULL;
  GstVaapiEncoderStatus status;
  GstBuffer *out_buffer;
  GstFlowReturn ret;

  status = gst_vaapi_encoder_get_buffer_with_timeout (encode->encoder,
      &codedbuf_proxy, timeout);
  if (status == GST_VAAPI_ENCODER_STATUS_NO_BUFFER)
    return GST_VAAPI_ENCODE_FLOW_TIMEOUT;
  if (status != GST_VAAPI_ENCODER_STATUS_SUCCESS)
    goto error_get_buffer;

  out_frame = gst_vaapi_coded_buffer_proxy_get_user_data (codedbuf_proxy);
  if (!out_frame)
    goto error_get_buffer;
  gst_video_codec_frame_ref (out_frame);
  gst_video_codec_frame_set_user_data (out_frame, NULL, NULL);

  /* Update output state */
  GST_VIDEO_ENCODER_STREAM_LOCK (encode);
  if (!ensure_output_state (encode))
    goto error_output_state;
  GST_VIDEO_ENCODER_STREAM_UNLOCK (encode);

  /* Allocate and copy buffer into system memory */
  out_buffer = NULL;
  ret = klass->alloc_buffer (encode,
      GST_VAAPI_CODED_BUFFER_PROXY_BUFFER (codedbuf_proxy), &out_buffer);

  gst_vaapi_coded_buffer_proxy_replace (&codedbuf_proxy, NULL);
  if (ret != GST_FLOW_OK)
    goto error_allocate_buffer;

  gst_buffer_replace (&out_frame->output_buffer, out_buffer);
  gst_buffer_unref (out_buffer);

  GST_TRACE_OBJECT (encode, "output:%" GST_TIME_FORMAT ", size:%zu",
      GST_TIME_ARGS (out_frame->pts), gst_buffer_get_size (out_buffer));

  return gst_video_encoder_finish_frame (venc, out_frame);

  /* ERRORS */
error_get_buffer:
  {
    GST_ERROR ("failed to get encoded buffer (status %d)", status);
    if (codedbuf_proxy)
      gst_vaapi_coded_buffer_proxy_unref (codedbuf_proxy);
    return GST_FLOW_ERROR;
  }
error_allocate_buffer:
  {
    GST_ERROR ("failed to allocate encoded buffer in system memory");
    if (out_buffer)
      gst_buffer_unref (out_buffer);
    gst_video_codec_frame_unref (out_frame);
    return ret;
  }
error_output_state:
  {
    GST_ERROR ("failed to negotiate output state (status %d)", status);
    GST_VIDEO_ENCODER_STREAM_UNLOCK (encode);
    gst_video_codec_frame_unref (out_frame);
    return GST_FLOW_NOT_NEGOTIATED;
  }
}

static void
gst_vaapiencode_buffer_loop (GstVaapiEncode * encode)
{
  GstFlowReturn ret;
  const gint64 timeout = 50000; /* microseconds */

  ret = gst_vaapiencode_push_frame (encode, timeout);
  if (ret == GST_FLOW_OK || ret == GST_VAAPI_ENCODE_FLOW_TIMEOUT)
    return;

  GST_LOG_OBJECT (encode, "pausing task, reason %s", gst_flow_get_name (ret));
  gst_pad_pause_task (GST_VAAPI_PLUGIN_BASE_SRC_PAD (encode));
}

static GArray *
get_profiles (GstVaapiEncode * encode)
{
  GstVaapiEncodeClass *klass = GST_VAAPIENCODE_GET_CLASS (encode);
  GArray *profiles = NULL;

  if (klass->get_allowed_profiles) {
    GstCaps *allowed =
        gst_pad_get_allowed_caps (GST_VAAPI_PLUGIN_BASE_SRC_PAD (encode));
    GST_LOG_OBJECT (encode,
        "Get allowed sink caps from downstream %" GST_PTR_FORMAT, allowed);
    if (allowed && !gst_caps_is_empty (allowed) && !gst_caps_is_any (allowed))
      profiles = klass->get_allowed_profiles (encode, allowed);

    if (allowed)
      gst_caps_unref (allowed);

    if (profiles)
      return profiles;
  }

  profiles = gst_vaapi_encoder_get_available_profiles (encode->encoder);
  return profiles;
}

static gboolean
ensure_allowed_sinkpad_caps (GstVaapiEncode * encode)
{
  GstCaps *out_caps = NULL;
  GArray *formats = NULL;
  gboolean ret = FALSE;
  GArray *profiles = NULL;
  gint min_width, min_height, max_width, max_height;
  guint mem_types;

  if (encode->allowed_sinkpad_caps)
    return TRUE;
  if (!encode->encoder)
    return TRUE;

  /* First, get all possible profiles. */
  profiles = get_profiles (encode);
  if (profiles == NULL)
    goto failed_get_profiles;

  /* Then get all supported formats, all these formats should be recognized
     in video-format map. */
  formats = gst_vaapi_encoder_get_surface_attributes (encode->encoder, profiles,
      &min_width, &min_height, &max_width, &max_height, &mem_types);
  if (!formats)
    goto failed_get_attributes;

  out_caps = gst_vaapi_build_caps_from_formats (formats, min_width, min_height,
      max_width, max_height, mem_types);
  if (!out_caps)
    goto failed_create_caps;

  gst_caps_replace (&encode->allowed_sinkpad_caps, out_caps);
  GST_INFO_OBJECT (encode, "Allowed sink caps %" GST_PTR_FORMAT,
      encode->allowed_sinkpad_caps);

  ret = TRUE;

bail:
  if (!encode->allowed_sinkpad_caps)
    encode->allowed_sinkpad_caps = gst_caps_new_empty ();

  if (profiles)
    g_array_unref (profiles);
  if (out_caps)
    gst_caps_unref (out_caps);
  if (formats)
    g_array_unref (formats);
  return ret;

failed_get_attributes:
  {
    GST_WARNING_OBJECT (encode, "failed to get surface attributes");
    goto bail;
  }
failed_create_caps:
  {
    GST_WARNING_OBJECT (encode, "failed to create sink caps");
    goto bail;
  }
failed_get_profiles:
  {
    GST_WARNING_OBJECT (encode, "failed to get supported profiles");
    goto bail;
  }
}

static GstCaps *
gst_vaapiencode_get_caps (GstVideoEncoder * venc, GstCaps * filter)
{
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (venc);
  GstCaps *result;

  ensure_allowed_sinkpad_caps (encode);
  result = gst_video_encoder_proxy_getcaps (venc, encode->allowed_sinkpad_caps,
      filter);

  GST_DEBUG_OBJECT (venc, "Negotiated sink caps %" GST_PTR_FORMAT, result);
  return result;
}

static gboolean
gst_vaapiencode_destroy (GstVaapiEncode * encode)
{
  if (encode->input_state) {
    gst_video_codec_state_unref (encode->input_state);
    encode->input_state = NULL;
  }

  if (encode->output_state) {
    gst_video_codec_state_unref (encode->output_state);
    encode->output_state = NULL;
  }

  gst_caps_replace (&encode->allowed_sinkpad_caps, NULL);
  gst_vaapi_encoder_replace (&encode->encoder, NULL);
  return TRUE;
}

static void
gst_vaapiencode_purge (GstVaapiEncode * encode)
{
  GstVaapiCodedBufferProxy *codedbuf_proxy = NULL;
  GstVaapiEncoderStatus status;
  GstVideoCodecFrame *out_frame;

  do {
    status = gst_vaapi_encoder_get_buffer_with_timeout (encode->encoder,
        &codedbuf_proxy, 0);
    if (status == GST_VAAPI_ENCODER_STATUS_SUCCESS) {
      out_frame = gst_vaapi_coded_buffer_proxy_get_user_data (codedbuf_proxy);
      if (out_frame)
        gst_video_codec_frame_set_user_data (out_frame, NULL, NULL);

      gst_vaapi_coded_buffer_proxy_unref (codedbuf_proxy);
    }
  } while (status == GST_VAAPI_ENCODER_STATUS_SUCCESS);
}

static gboolean
ensure_encoder (GstVaapiEncode * encode)
{
  GstVaapiEncodeClass *klass = GST_VAAPIENCODE_GET_CLASS (encode);
  guint i;

  g_return_val_if_fail (klass->alloc_encoder, FALSE);

  if (encode->encoder)
    return FALSE;

  encode->encoder = klass->alloc_encoder (encode,
      GST_VAAPI_PLUGIN_BASE_DISPLAY (encode));
  if (!encode->encoder)
    return FALSE;

  if (encode->prop_values && encode->prop_values->len) {
    for (i = 0; i < encode->prop_values->len; i++) {
      PropValue *const prop_value = g_ptr_array_index (encode->prop_values, i);
      g_object_set_property ((GObject *) encode->encoder,
          g_param_spec_get_name (prop_value->pspec), &prop_value->value);
    }
    /* clear alll the cache */
    g_ptr_array_unref (encode->prop_values);
    encode->prop_values = NULL;
  }

  return TRUE;
}

static gboolean
gst_vaapiencode_open (GstVideoEncoder * venc)
{
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (venc);
  GstVaapiDisplay *const old_display = GST_VAAPI_PLUGIN_BASE_DISPLAY (encode);
  gboolean success;

  if (!gst_vaapi_plugin_base_open (GST_VAAPI_PLUGIN_BASE (encode)))
    return FALSE;

  GST_VAAPI_PLUGIN_BASE_DISPLAY (encode) = NULL;
  success = ensure_display (encode);
  if (old_display)
    gst_object_unref (old_display);
  return success;
}

static gboolean
gst_vaapiencode_start (GstVideoEncoder * venc)
{
  return ensure_encoder (GST_VAAPIENCODE_CAST (venc));
}

static gboolean
gst_vaapiencode_stop (GstVideoEncoder * venc)
{
  return gst_vaapiencode_destroy (GST_VAAPIENCODE_CAST (venc));
}

static gboolean
gst_vaapiencode_close (GstVideoEncoder * venc)
{
  gst_vaapi_plugin_base_close (GST_VAAPI_PLUGIN_BASE (venc));
  return TRUE;
}

static gboolean
set_codec_state (GstVaapiEncode * encode, GstVideoCodecState * state)
{
  GstVaapiEncodeClass *const klass = GST_VAAPIENCODE_GET_CLASS (encode);
  GstVaapiEncoderStatus status;

  g_return_val_if_fail (encode->encoder, FALSE);

  /* Initialize codec specific parameters */
  if (klass->set_config && !klass->set_config (encode))
    return FALSE;

  status = gst_vaapi_encoder_set_codec_state (encode->encoder, state);
  if (status != GST_VAAPI_ENCODER_STATUS_SUCCESS)
    return FALSE;
  return TRUE;
}

static gboolean
gst_vaapiencode_set_format (GstVideoEncoder * venc, GstVideoCodecState * state)
{
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (venc);
  GstVaapiEncoderStatus status;

  g_return_val_if_fail (state->caps != NULL, FALSE);

  if (!set_codec_state (encode, state))
    return FALSE;

  if (!gst_vaapi_plugin_base_set_caps (GST_VAAPI_PLUGIN_BASE (encode),
          state->caps, NULL))
    return FALSE;

  GST_VIDEO_ENCODER_STREAM_UNLOCK (encode);
  status = gst_vaapi_encoder_flush (encode->encoder);
  GST_VIDEO_ENCODER_STREAM_LOCK (encode);
  if (status != GST_VAAPI_ENCODER_STATUS_SUCCESS)
    return FALSE;

  gst_vaapiencode_purge (encode);

  if (encode->input_state)
    gst_video_codec_state_unref (encode->input_state);
  encode->input_state = gst_video_codec_state_ref (state);
  encode->input_state_changed = TRUE;

  /* Store some tags */
  {
    GstTagList *tags = gst_tag_list_new_empty ();
    const gchar *encoder, *codec;
    guint bitrate = 0;

    g_object_get (encode, "bitrate", &bitrate, NULL);
    gst_tag_list_add (tags, GST_TAG_MERGE_REPLACE, GST_TAG_NOMINAL_BITRATE,
        bitrate, NULL);

    if ((encoder =
            gst_element_class_get_metadata (GST_ELEMENT_GET_CLASS (encode),
                GST_ELEMENT_METADATA_LONGNAME)))
      gst_tag_list_add (tags, GST_TAG_MERGE_REPLACE, GST_TAG_ENCODER, encoder,
          NULL);

    if ((codec = gst_vaapi_codec_get_name
            (gst_vaapi_get_codec_from_caps (state->caps))))
      gst_tag_list_add (tags, GST_TAG_MERGE_REPLACE, GST_TAG_CODEC, codec,
          NULL);

    gst_video_encoder_merge_tags (venc, tags, GST_TAG_MERGE_REPLACE);
    gst_tag_list_unref (tags);
  }

  return TRUE;
}

static GstFlowReturn
gst_vaapiencode_handle_frame (GstVideoEncoder * venc,
    GstVideoCodecFrame * frame)
{
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (venc);
  GstPad *const srcpad = GST_VAAPI_PLUGIN_BASE_SRC_PAD (encode);
  GstVaapiEncoderStatus status;
  GstVaapiVideoMeta *meta;
  GstVaapiSurfaceProxy *proxy;
  GstFlowReturn ret;
  GstBuffer *buf;
  GstTaskState task_state;

  task_state = gst_pad_get_task_state (srcpad);
  if (task_state == GST_TASK_STOPPED || task_state == GST_TASK_PAUSED)
    if (!gst_pad_start_task (srcpad,
            (GstTaskFunction) gst_vaapiencode_buffer_loop, encode, NULL))
      goto error_task_failed;

  buf = NULL;
  ret = gst_vaapi_plugin_base_get_input_buffer (GST_VAAPI_PLUGIN_BASE (encode),
      frame->input_buffer, &buf);
  if (ret != GST_FLOW_OK)
    goto error_buffer_invalid;

  gst_buffer_replace (&frame->input_buffer, buf);
  gst_buffer_unref (buf);

  meta = gst_buffer_get_vaapi_video_meta (buf);
  if (!meta)
    goto error_buffer_no_meta;

  proxy = gst_vaapi_video_meta_get_surface_proxy (meta);
  if (!proxy)
    goto error_buffer_no_surface_proxy;

  gst_video_codec_frame_set_user_data (frame,
      gst_vaapi_surface_proxy_ref (proxy),
      (GDestroyNotify) gst_vaapi_surface_proxy_unref);

  GST_VIDEO_ENCODER_STREAM_UNLOCK (encode);
  status = gst_vaapi_encoder_put_frame (encode->encoder, frame);
  GST_VIDEO_ENCODER_STREAM_LOCK (encode);
  if (status < GST_VAAPI_ENCODER_STATUS_SUCCESS)
    goto error_encode_frame;

  gst_video_codec_frame_unref (frame);
  return GST_FLOW_OK;

  /* ERRORS */
error_task_failed:
  {
    GST_ELEMENT_ERROR (venc, RESOURCE, FAILED,
        ("Failed to start encoding thread."), (NULL));
    gst_video_codec_frame_unref (frame);
    return GST_FLOW_ERROR;
  }
error_buffer_invalid:
  {
    if (buf)
      gst_buffer_unref (buf);
    gst_video_codec_frame_unref (frame);
    return ret;
  }
error_buffer_no_meta:
  {
    GST_ERROR ("failed to get GstVaapiVideoMeta information");
    gst_video_codec_frame_unref (frame);
    return GST_FLOW_ERROR;
  }
error_buffer_no_surface_proxy:
  {
    GST_ERROR ("failed to get VA surface proxy");
    gst_video_codec_frame_unref (frame);
    return GST_FLOW_ERROR;
  }
error_encode_frame:
  {
    GST_ERROR ("failed to encode frame %d (status %d)",
        frame->system_frame_number, status);
    gst_video_codec_frame_unref (frame);
    return GST_FLOW_ERROR;
  }
}

static GstFlowReturn
gst_vaapiencode_finish (GstVideoEncoder * venc)
{
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (venc);
  GstVaapiEncoderStatus status;
  GstFlowReturn ret = GST_FLOW_OK;

  /* Don't try to destroy encoder if none was created in the first place.
     Return "not-negotiated" error since this means we did not even reach
     GstVideoEncoder::set_format() state, where the encoder could have
     been created */
  if (!encode->encoder)
    return GST_FLOW_NOT_NEGOTIATED;

  GST_VIDEO_ENCODER_STREAM_UNLOCK (encode);

  status = gst_vaapi_encoder_flush (encode->encoder);

  gst_pad_stop_task (GST_VAAPI_PLUGIN_BASE_SRC_PAD (encode));

  GST_VIDEO_ENCODER_STREAM_LOCK (encode);

  while (status == GST_VAAPI_ENCODER_STATUS_SUCCESS && ret == GST_FLOW_OK)
    ret = gst_vaapiencode_push_frame (encode, 0);

  if (ret == GST_VAAPI_ENCODE_FLOW_TIMEOUT)
    ret = GST_FLOW_OK;
  return ret;
}

static GstStateChangeReturn
gst_vaapiencode_change_state (GstElement * element, GstStateChange transition)
{
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (element);
  GstVaapiEncoderStatus status;

  switch (transition) {
    case GST_STATE_CHANGE_PAUSED_TO_READY:
      gst_pad_stop_task (GST_VAAPI_PLUGIN_BASE_SRC_PAD (encode));

      status = gst_vaapi_encoder_flush (encode->encoder);
      if (status != GST_VAAPI_ENCODER_STATUS_SUCCESS)
        goto flush_error;

      GST_VIDEO_ENCODER_STREAM_LOCK (encode);
      gst_vaapiencode_purge (encode);
      GST_VIDEO_ENCODER_STREAM_UNLOCK (encode);
      break;
    default:
      break;
  }
  return
      GST_ELEMENT_CLASS (gst_vaapiencode_parent_class)->change_state (element,
      transition);

flush_error:
  {
    GST_ERROR ("failed to flush pending encoded frames");
    return GST_STATE_CHANGE_FAILURE;
  }
}

static gboolean
gst_vaapiencode_propose_allocation (GstVideoEncoder * venc, GstQuery * query)
{
  GstVaapiPluginBase *const plugin = GST_VAAPI_PLUGIN_BASE (venc);

  if (!gst_vaapi_plugin_base_propose_allocation (plugin, query))
    return FALSE;
  return TRUE;
}

static gboolean
gst_vaapiencode_sink_event (GstVideoEncoder * venc, GstEvent * event)
{
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (venc);
  GstPad *const srcpad = GST_VAAPI_PLUGIN_BASE_SRC_PAD (encode);
  gboolean ret;

  ret = GST_VIDEO_ENCODER_CLASS (gst_vaapiencode_parent_class)->sink_event
      (venc, event);
  if (!ret)
    return FALSE;

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_FLUSH_START:
      gst_pad_pause_task (srcpad);
      break;
    case GST_EVENT_FLUSH_STOP:
      ret = gst_pad_start_task (srcpad,
          (GstTaskFunction) gst_vaapiencode_buffer_loop, encode, NULL);
      break;
    default:
      break;
  }

  return ret;
}

static gboolean
gst_vaapiencode_flush (GstVideoEncoder * venc)
{
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (venc);
  GstVaapiEncoderStatus status;

  if (!encode->encoder)
    return FALSE;

  GST_LOG_OBJECT (encode, "flushing");

  GST_VIDEO_ENCODER_STREAM_UNLOCK (encode);
  status = gst_vaapi_encoder_flush (encode->encoder);
  GST_VIDEO_ENCODER_STREAM_LOCK (encode);
  if (status != GST_VAAPI_ENCODER_STATUS_SUCCESS)
    return FALSE;

  gst_vaapiencode_purge (encode);

  gst_vaapi_encoder_replace (&encode->encoder, NULL);
  if (!ensure_encoder (encode))
    return FALSE;
  if (!set_codec_state (encode, encode->input_state))
    return FALSE;

  return TRUE;
}

static void
gst_vaapiencode_finalize (GObject * object)
{
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (object);

  gst_vaapiencode_destroy (encode);

  if (encode->prop_values) {
    g_ptr_array_unref (encode->prop_values);
    encode->prop_values = NULL;
  }

  gst_vaapi_plugin_base_finalize (GST_VAAPI_PLUGIN_BASE (object));
  G_OBJECT_CLASS (gst_vaapiencode_parent_class)->finalize (object);
}

static void
gst_vaapiencode_init (GstVaapiEncode * encode)
{
  GstVaapiPluginBase *const plugin = GST_VAAPI_PLUGIN_BASE (encode);

  gst_vaapi_plugin_base_init (GST_VAAPI_PLUGIN_BASE (encode), GST_CAT_DEFAULT);
  gst_pad_use_fixed_caps (GST_VAAPI_PLUGIN_BASE_SRC_PAD (plugin));
}

static void
gst_vaapiencode_class_init (GstVaapiEncodeClass * klass)
{
  GObjectClass *const object_class = G_OBJECT_CLASS (klass);
  GstElementClass *const element_class = GST_ELEMENT_CLASS (klass);
  GstVideoEncoderClass *const venc_class = GST_VIDEO_ENCODER_CLASS (klass);

  GST_DEBUG_CATEGORY_INIT (gst_vaapiencode_debug,
      GST_PLUGIN_NAME, 0, GST_PLUGIN_DESC);

  gst_vaapi_plugin_base_class_init (GST_VAAPI_PLUGIN_BASE_CLASS (klass));

  object_class->finalize = gst_vaapiencode_finalize;

  element_class->set_context = gst_vaapi_base_set_context;
  element_class->change_state =
      GST_DEBUG_FUNCPTR (gst_vaapiencode_change_state);

  venc_class->open = GST_DEBUG_FUNCPTR (gst_vaapiencode_open);
  venc_class->close = GST_DEBUG_FUNCPTR (gst_vaapiencode_close);
  venc_class->start = GST_DEBUG_FUNCPTR (gst_vaapiencode_start);
  venc_class->stop = GST_DEBUG_FUNCPTR (gst_vaapiencode_stop);
  venc_class->set_format = GST_DEBUG_FUNCPTR (gst_vaapiencode_set_format);
  venc_class->handle_frame = GST_DEBUG_FUNCPTR (gst_vaapiencode_handle_frame);
  venc_class->finish = GST_DEBUG_FUNCPTR (gst_vaapiencode_finish);
  venc_class->getcaps = GST_DEBUG_FUNCPTR (gst_vaapiencode_get_caps);
  venc_class->propose_allocation =
      GST_DEBUG_FUNCPTR (gst_vaapiencode_propose_allocation);
  venc_class->flush = GST_DEBUG_FUNCPTR (gst_vaapiencode_flush);
  venc_class->sink_event = GST_DEBUG_FUNCPTR (gst_vaapiencode_sink_event);

  klass->alloc_buffer = gst_vaapiencode_default_alloc_buffer;

  venc_class->src_query = GST_DEBUG_FUNCPTR (gst_vaapiencode_src_query);
  venc_class->sink_query = GST_DEBUG_FUNCPTR (gst_vaapiencode_sink_query);

  gst_type_mark_as_plugin_api (GST_TYPE_VAAPIENCODE, 0);
}

/* Only used by the drived class */
void
gst_vaapiencode_set_property_subclass (GObject * object,
    guint prop_id, const GValue * value, GParamSpec * pspec)
{
  GstVaapiEncodeClass *const encode_class = GST_VAAPIENCODE_GET_CLASS (object);
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (object);
  PropValue *prop_value;

  if (prop_id <= PROP_BASE || prop_id >= encode_class->prop_num) {
    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    return;
  }

  /* direct forward the property to encoder */
  if (encode->encoder) {
    g_object_set_property ((GObject *) encode->encoder,
        g_param_spec_get_name (pspec), value);
    return;
  }

  if (encode->prop_values) {
    /* Delete the same prop already in cache */
    prop_value = prop_value_lookup_entry (encode->prop_values, prop_id);
    if (prop_value)
      g_ptr_array_remove (encode->prop_values, prop_value);
  } else {
    encode->prop_values =
        g_ptr_array_new_with_free_func ((GDestroyNotify) prop_value_free);
  }

  /* The encoder is delay created, we need to cache the property setting */
  prop_value = prop_value_new_entry (prop_id, pspec, value);
  g_ptr_array_add (encode->prop_values, prop_value);
}

/* Only used by the drived class */
void
gst_vaapiencode_get_property_subclass (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstVaapiEncodeClass *const encode_class = GST_VAAPIENCODE_GET_CLASS (object);
  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (object);
  PropValue *prop_value = NULL;

  if (prop_id <= PROP_BASE || prop_id >= encode_class->prop_num) {
    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    return;
  }

  /* direct forward the property to encoder */
  if (encode->encoder) {
    g_object_get_property ((GObject *) encode->encoder,
        g_param_spec_get_name (pspec), value);
    return;
  }

  if (encode->prop_values)
    prop_value = prop_value_lookup_entry (encode->prop_values, prop_id);

  if (prop_value) {
    /* In the cache */
    g_value_copy (&prop_value->value, value);
  } else {
    /* set the default value */
    g_param_value_set_default (pspec, value);
  }
}

/* Called by drived class to install all properties. The encode base class
   does not have any property, all the properties of the according encoderXXX
   class are installed to encodeXXX class. */
gboolean
gst_vaapiencode_class_install_properties (GstVaapiEncodeClass * klass,
    GObjectClass * encoder_class)
{
  GObjectClass *const object_class = G_OBJECT_CLASS (klass);
  guint i, n_props, installed;
  GParamSpec **specs = NULL;
  GParamSpec *pspec;
  GParamSpec *new_spec;
  GParamFlags flags;

  if (encoder_class)
    specs = g_object_class_list_properties (encoder_class, &n_props);
  if (!specs)
    return FALSE;

  installed = 0;
  for (i = 0; i < n_props; i++) {
    pspec = specs[i];

    /* Encoder do not want to expose */
    if (!(pspec->flags & GST_VAAPI_PARAM_ENCODER_EXPOSURE))
      continue;
    /* Can only set on encoder init time */
    if (pspec->flags & G_PARAM_CONSTRUCT_ONLY)
      continue;

    /* filter out the G_PARAM_CONSTRUCT, the encoder created later, no need
       to set the init value in encode.
       Also no GST_VAAPI_PARAM_ENCODER_EXPOSURE */
    flags = pspec->flags & (~(GST_VAAPI_PARAM_ENCODER_EXPOSURE |
            G_PARAM_CONSTRUCT));

    if (G_PARAM_SPEC_TYPE (pspec) == G_TYPE_PARAM_UINT) {
      GParamSpecUInt *pspecuint = G_PARAM_SPEC_UINT (pspec);
      new_spec = g_param_spec_uint (g_param_spec_get_name (pspec),
          g_param_spec_get_nick (pspec), g_param_spec_get_blurb (pspec),
          pspecuint->minimum, pspecuint->maximum,
          pspecuint->default_value, flags);
    } else if (G_PARAM_SPEC_TYPE (pspec) == G_TYPE_PARAM_INT) {
      GParamSpecInt *pspecint = G_PARAM_SPEC_INT (pspec);
      new_spec = g_param_spec_int (g_param_spec_get_name (pspec),
          g_param_spec_get_nick (pspec), g_param_spec_get_blurb (pspec),
          pspecint->minimum, pspecint->maximum, pspecint->default_value, flags);
    } else if (G_IS_PARAM_SPEC_ENUM (pspec)) {
      GParamSpecEnum *pspecenum = G_PARAM_SPEC_ENUM (pspec);
      new_spec = g_param_spec_enum (g_param_spec_get_name (pspec),
          g_param_spec_get_nick (pspec),
          g_param_spec_get_blurb (pspec),
          pspec->value_type, pspecenum->default_value, flags);
    } else if (G_IS_PARAM_SPEC_BOOLEAN (pspec)) {
      GParamSpecBoolean *pspecbool = G_PARAM_SPEC_BOOLEAN (pspec);
      new_spec = g_param_spec_boolean (g_param_spec_get_name (pspec),
          g_param_spec_get_nick (pspec), g_param_spec_get_blurb (pspec),
          pspecbool->default_value, flags);
    } else if (G_IS_PARAM_SPEC_FLAGS (pspec)) {
      GParamSpecFlags *pspecflags = G_PARAM_SPEC_FLAGS (pspec);
      new_spec = g_param_spec_flags (g_param_spec_get_name (pspec),
          g_param_spec_get_nick (pspec), g_param_spec_get_blurb (pspec),
          pspec->value_type, pspecflags->default_value, flags);
    } else if (GST_IS_PARAM_SPEC_ARRAY_LIST (pspec)) {
      GstParamSpecArray *pspecarray = GST_PARAM_SPEC_ARRAY_LIST (pspec);
      new_spec = gst_param_spec_array (g_param_spec_get_name (pspec),
          g_param_spec_get_nick (pspec), g_param_spec_get_blurb (pspec),
          pspecarray->element_spec, flags);
    } else {
      GST_WARNING ("encoder's %s property has a unimplemented"
          " type to expose to encode, the encode may lose the %s property",
          g_param_spec_get_name (pspec), g_param_spec_get_name (pspec));
      continue;
    }

    g_object_class_install_property (object_class, PROP_BASE + 1 + installed,
        new_spec);
    installed++;
  }

  g_free (specs);
  klass->prop_num = PROP_BASE + 1 + installed;
  return TRUE;
}