gstreamer/gst/vaapi/gstvaapidecode.c

/*
 *  gstvaapidecode.c - VA-API video decoder
 *
 *  Copyright (C) 2010-2011 Splitted-Desktop Systems
 *    Author: Gwenole Beauchesne <gwenole.beauchesne@splitted-desktop.com>
 *  Copyright (C) 2011-2014 Intel Corporation
 *    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
*/

/**
 * SECTION:gstvaapidecode
 * @short_description: A VA-API based video decoder
 *
 * vaapidecode decodes from raw bitstreams to surfaces suitable for
 * the vaapisink element.
 */

#include "gstcompat.h"
#include <gst/vaapi/gstvaapidisplay.h>

#include "gstvaapidecode.h"
#include "gstvaapipluginutil.h"
#include "gstvaapivideobuffer.h"
#if (USE_GLX || USE_EGL)
#include "gstvaapivideometa_texture.h"
#endif
#include "gstvaapivideobufferpool.h"
#include "gstvaapivideomemory.h"

#include <gst/vaapi/gstvaapidecoder_h264.h>
#include <gst/vaapi/gstvaapidecoder_jpeg.h>
#include <gst/vaapi/gstvaapidecoder_mpeg2.h>
#include <gst/vaapi/gstvaapidecoder_mpeg4.h>
#include <gst/vaapi/gstvaapidecoder_vc1.h>
#include <gst/vaapi/gstvaapidecoder_vp8.h>
#include <gst/vaapi/gstvaapidecoder_h265.h>
#include <gst/vaapi/gstvaapidecoder_vp9.h>

#define GST_PLUGIN_NAME "vaapidecode"
#define GST_PLUGIN_DESC "A VA-API based video decoder"

#define GST_VAAPI_DECODE_FLOW_PARSE_DATA        GST_FLOW_CUSTOM_SUCCESS_2

GST_DEBUG_CATEGORY_STATIC (gst_debug_vaapidecode);
#define GST_CAT_DEFAULT gst_debug_vaapidecode

/* Default templates */
#define GST_CAPS_CODEC(CODEC) CODEC "; "

/* *INDENT-OFF* */
static const char gst_vaapidecode_sink_caps_str[] =
    GST_CAPS_CODEC("video/mpeg, mpegversion=2, systemstream=(boolean)false")
    GST_CAPS_CODEC("video/mpeg, mpegversion=4")
    GST_CAPS_CODEC("video/x-divx")
    GST_CAPS_CODEC("video/x-xvid")
    GST_CAPS_CODEC("video/x-h263")
    GST_CAPS_CODEC("video/x-h264")
#if USE_HEVC_DECODER
    GST_CAPS_CODEC("video/x-h265")
#endif
    GST_CAPS_CODEC("video/x-wmv")
#if USE_VP8_DECODER
    GST_CAPS_CODEC("video/x-vp8")
#endif
#if USE_JPEG_DECODER
    GST_CAPS_CODEC("image/jpeg")
#endif
#if USE_VP9_DECODER
    GST_CAPS_CODEC("video/x-vp9")
#endif
    ;

static const char gst_vaapidecode_src_caps_str[] =
    GST_VAAPI_MAKE_SURFACE_CAPS ";"
    GST_VAAPI_MAKE_GLTEXUPLOAD_CAPS ";"
    GST_VIDEO_CAPS_MAKE("{ I420, YV12, NV12 }");

static GstStaticPadTemplate gst_vaapidecode_sink_factory =
    GST_STATIC_PAD_TEMPLATE(
        "sink",
        GST_PAD_SINK,
        GST_PAD_ALWAYS,
        GST_STATIC_CAPS(gst_vaapidecode_sink_caps_str));

static GstStaticPadTemplate gst_vaapidecode_src_factory =
    GST_STATIC_PAD_TEMPLATE(
        "src",
        GST_PAD_SRC,
        GST_PAD_ALWAYS,
        GST_STATIC_CAPS(gst_vaapidecode_src_caps_str));

G_DEFINE_TYPE_WITH_CODE(
    GstVaapiDecode,
    gst_vaapidecode,
    GST_TYPE_VIDEO_DECODER,
    GST_VAAPI_PLUGIN_BASE_INIT_INTERFACES)
/* *INDENT-ON* */

static gboolean
gst_vaapidecode_update_sink_caps (GstVaapiDecode * decode, GstCaps * caps);
static gboolean gst_vaapidecode_update_src_caps (GstVaapiDecode * decode);

static gboolean
gst_vaapi_decode_input_state_replace (GstVaapiDecode * decode,
    const GstVideoCodecState * new_state);

static gboolean
gst_vaapidecode_sink_query (GstVideoDecoder * vdec, GstQuery * query);
static gboolean
gst_vaapidecode_src_query (GstVideoDecoder * vdec, GstQuery * query);

static void
gst_vaapi_decoder_state_changed (GstVaapiDecoder * decoder,
    const GstVideoCodecState * codec_state, gpointer user_data)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (user_data);

  g_assert (decode->decoder == decoder);

  if (!gst_vaapi_decode_input_state_replace (decode, codec_state))
    return;
  if (!gst_vaapidecode_update_sink_caps (decode, decode->input_state->caps))
    return;

  decode->do_renego = TRUE;
}

static GstVideoCodecState *
copy_video_codec_state (const GstVideoCodecState * in_state)
{
  GstVideoCodecState *state;

  g_return_val_if_fail (in_state != NULL, NULL);

  state = g_slice_new0 (GstVideoCodecState);
  state->ref_count = 1;
  state->info = in_state->info;
  state->caps = gst_caps_copy (in_state->caps);
  if (in_state->codec_data)
    state->codec_data = gst_buffer_copy_deep (in_state->codec_data);

  return state;
}

static gboolean
gst_vaapi_decode_input_state_replace (GstVaapiDecode * decode,
    const GstVideoCodecState * new_state)
{
  if (decode->input_state) {
    if (new_state) {
      const GstCaps *curcaps = decode->input_state->caps;
      /* If existing caps are equal of the new state, keep the
       * existing state without renegotiating. */
      if (gst_caps_is_strictly_equal (curcaps, new_state->caps)) {
        GST_DEBUG ("Ignoring new caps %" GST_PTR_FORMAT
            " since are equal to current ones", new_state->caps);
        return FALSE;
      }
    }
    gst_video_codec_state_unref (decode->input_state);
  }

  if (new_state)
    decode->input_state = copy_video_codec_state (new_state);
  else
    decode->input_state = NULL;

  return TRUE;
}

static inline gboolean
gst_vaapidecode_update_sink_caps (GstVaapiDecode * decode, GstCaps * caps)
{
  GST_INFO_OBJECT (decode, "new sink caps = %" GST_PTR_FORMAT, caps);
  gst_caps_replace (&decode->sinkpad_caps, caps);
  return TRUE;
}

static gboolean
gst_vaapidecode_update_src_caps (GstVaapiDecode * decode)
{
  GstVideoDecoder *const vdec = GST_VIDEO_DECODER (decode);
  GstVideoCodecState *state, *ref_state;
  GstVideoInfo *vi;
  GstVideoFormat format = GST_VIDEO_FORMAT_I420;

  if (!decode->input_state)
    return FALSE;

  ref_state = decode->input_state;

  GstCapsFeatures *features = NULL;
  GstVaapiCapsFeature feature;

  feature =
      gst_vaapi_find_preferred_caps_feature (GST_VIDEO_DECODER_SRC_PAD (vdec),
      GST_VIDEO_INFO_FORMAT (&ref_state->info), &format);

  if (feature == GST_VAAPI_CAPS_FEATURE_NOT_NEGOTIATED)
    return FALSE;

  switch (feature) {
#if (USE_GLX || USE_EGL)
    case GST_VAAPI_CAPS_FEATURE_GL_TEXTURE_UPLOAD_META:
      features =
          gst_caps_features_new
          (GST_CAPS_FEATURE_META_GST_VIDEO_GL_TEXTURE_UPLOAD_META, NULL);
      break;
#endif
#if GST_CHECK_VERSION(1,3,1)
    case GST_VAAPI_CAPS_FEATURE_VAAPI_SURFACE:
      features =
          gst_caps_features_new (GST_CAPS_FEATURE_MEMORY_VAAPI_SURFACE, NULL);
      break;
#endif
    default:
      break;
  }

  state = gst_video_decoder_set_output_state (vdec, format,
      ref_state->info.width, ref_state->info.height, ref_state);
  if (!state || state->info.width == 0 || state->info.height == 0)
    return FALSE;

  vi = &state->info;

  state->caps = gst_video_info_to_caps (vi);
  if (features)
    gst_caps_set_features (state->caps, 0, features);
  GST_INFO_OBJECT (decode, "new src caps = %" GST_PTR_FORMAT, state->caps);
  gst_caps_replace (&decode->srcpad_caps, state->caps);
  gst_video_codec_state_unref (state);

  gint fps_n = GST_VIDEO_INFO_FPS_N (vi);
  gint fps_d = GST_VIDEO_INFO_FPS_D (vi);
  if (fps_n <= 0 || fps_d <= 0) {
    GST_DEBUG_OBJECT (decode, "forcing 25/1 framerate for latency calculation");
    fps_n = 25;
    fps_d = 1;
  }

  /* For parsing/preparation purposes we'd need at least 1 frame
   * latency in general, with perfectly known unit boundaries (NALU,
   * AU), and up to 2 frames when we need to wait for the second frame
   * start to determine the first frame is complete */
  GstClockTime latency = gst_util_uint64_scale (2 * GST_SECOND, fps_d, fps_n);
  gst_video_decoder_set_latency (vdec, latency, latency);

  return TRUE;
}

static void
gst_vaapidecode_release (GstVaapiDecode * decode)
{
  g_mutex_lock (&decode->surface_ready_mutex);
  g_cond_signal (&decode->surface_ready);
  g_mutex_unlock (&decode->surface_ready_mutex);
  gst_object_unref (decode);
}

static GstFlowReturn
gst_vaapidecode_push_decoded_frame (GstVideoDecoder * vdec,
    GstVideoCodecFrame * out_frame)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);
  GstVaapiSurfaceProxy *proxy;
  GstFlowReturn ret;
  const GstVaapiRectangle *crop_rect;
  GstVaapiVideoMeta *meta;
  guint flags, out_flags = 0;

  if (!GST_VIDEO_CODEC_FRAME_IS_DECODE_ONLY (out_frame)) {
    proxy = gst_video_codec_frame_get_user_data (out_frame);

    gst_vaapi_surface_proxy_set_destroy_notify (proxy,
        (GDestroyNotify) gst_vaapidecode_release, gst_object_ref (decode));

    ret = gst_video_decoder_allocate_output_frame (vdec, out_frame);
    if (ret != GST_FLOW_OK)
      goto error_create_buffer;

    meta = gst_buffer_get_vaapi_video_meta (out_frame->output_buffer);
    if (!meta)
      goto error_get_meta;
    gst_vaapi_video_meta_set_surface_proxy (meta, proxy);

    flags = gst_vaapi_surface_proxy_get_flags (proxy);
    if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_CORRUPTED)
      out_flags |= GST_BUFFER_FLAG_CORRUPTED;
    if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_INTERLACED) {
      out_flags |= GST_VIDEO_BUFFER_FLAG_INTERLACED;
      if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_TFF)
        out_flags |= GST_VIDEO_BUFFER_FLAG_TFF;
      if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_RFF)
        out_flags |= GST_VIDEO_BUFFER_FLAG_RFF;
      if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_ONEFIELD)
        out_flags |= GST_VIDEO_BUFFER_FLAG_ONEFIELD;
    }
    GST_BUFFER_FLAG_SET (out_frame->output_buffer, out_flags);

#if GST_CHECK_VERSION(1,5,0)
    /* First-in-bundle flag only appeared in 1.5 dev */
    if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_FFB) {
      GST_BUFFER_FLAG_SET (out_frame->output_buffer,
          GST_VIDEO_BUFFER_FLAG_FIRST_IN_BUNDLE);
    }
#endif

    crop_rect = gst_vaapi_surface_proxy_get_crop_rect (proxy);
    if (crop_rect) {
      GstVideoCropMeta *const crop_meta =
          gst_buffer_add_video_crop_meta (out_frame->output_buffer);
      if (crop_meta) {
        crop_meta->x = crop_rect->x;
        crop_meta->y = crop_rect->y;
        crop_meta->width = crop_rect->width;
        crop_meta->height = crop_rect->height;
      }
    }
#if (USE_GLX || USE_EGL)
    if (decode->has_texture_upload_meta)
      gst_buffer_ensure_texture_upload_meta (out_frame->output_buffer);
#endif
  }

  ret = gst_video_decoder_finish_frame (vdec, out_frame);
  if (ret != GST_FLOW_OK)
    goto error_commit_buffer;

  gst_video_codec_frame_unref (out_frame);
  return GST_FLOW_OK;

  /* ERRORS */
error_create_buffer:
  {
    const GstVaapiID surface_id =
        gst_vaapi_surface_get_id (GST_VAAPI_SURFACE_PROXY_SURFACE (proxy));

    GST_ELEMENT_ERROR (vdec, STREAM, FAILED,
        ("Failed to create sink buffer"),
        ("video sink failed to create video buffer for proxy'ed "
            "surface %" GST_VAAPI_ID_FORMAT, GST_VAAPI_ID_ARGS (surface_id)));
    gst_video_decoder_drop_frame (vdec, out_frame);
    gst_video_codec_frame_unref (out_frame);
    return GST_FLOW_ERROR;
  }
error_get_meta:
  {
    GST_ELEMENT_ERROR (vdec, STREAM, FAILED,
        ("Failed to get vaapi video meta attached to video buffer"),
        ("Failed to get vaapi video meta attached to video buffer"));
    gst_video_decoder_drop_frame (vdec, out_frame);
    gst_video_codec_frame_unref (out_frame);
    return GST_FLOW_ERROR;
  }
error_commit_buffer:
  {
    GST_INFO_OBJECT (decode, "downstream element rejected the frame (%s [%d])",
        gst_flow_get_name (ret), ret);
    gst_video_codec_frame_unref (out_frame);
    return ret;
  }
}

static gboolean
gst_vaapidecode_negotiate (GstVaapiDecode * decode)
{
  GstVideoDecoder *const vdec = GST_VIDEO_DECODER (decode);
  GstVaapiPluginBase *const plugin = GST_VAAPI_PLUGIN_BASE (vdec);

  if (!decode->do_renego)
    return TRUE;

  GST_DEBUG_OBJECT (decode, "Input codec state changed, doing renegotiation");

  if (!gst_vaapi_plugin_base_set_caps (plugin, decode->sinkpad_caps, NULL))
    return FALSE;
  if (!gst_vaapidecode_update_src_caps (decode))
    return FALSE;
  if (!gst_video_decoder_negotiate (vdec))
    return FALSE;
  if (!gst_vaapi_plugin_base_set_caps (plugin, NULL, decode->srcpad_caps))
    return FALSE;

  decode->do_renego = FALSE;

  return TRUE;
}

static GstFlowReturn
gst_vaapidecode_push_all_decoded_frames (GstVaapiDecode * decode)
{
  GstVideoDecoder *const vdec = GST_VIDEO_DECODER (decode);
  GstVaapiDecoderStatus status;
  GstVideoCodecFrame *out_frame;
  GstFlowReturn ret;

  for (;;) {
    status = gst_vaapi_decoder_get_frame (decode->decoder, &out_frame);

    switch (status) {
      case GST_VAAPI_DECODER_STATUS_SUCCESS:
        ret = gst_vaapidecode_push_decoded_frame (vdec, out_frame);
        if (ret != GST_FLOW_OK)
          return ret;
        break;
      case GST_VAAPI_DECODER_STATUS_ERROR_NO_DATA:
        /* Delayed the pool re-negotiation untill we push all decoded (and queued)
         * frames downstream. Otherwise for the multi-resolution videos, the
         * GstVideoVideoMemory will be having wrong resolution.
         * commit 6eba201f3252eba6a99ab7da7a4c662091a3e884 */
        if (!gst_vaapidecode_negotiate (decode))
          return GST_FLOW_ERROR;
        return GST_FLOW_OK;
      default:
        GST_VIDEO_DECODER_ERROR (vdec, 1, STREAM, DECODE, ("Decoding failed"),
            ("Unknown decoding error"), ret);
        return ret;
    }
  }
  g_assert_not_reached ();
}

static GstFlowReturn
gst_vaapidecode_handle_frame (GstVideoDecoder * vdec,
    GstVideoCodecFrame * frame)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);
  GstVaapiDecoderStatus status;
  GstFlowReturn ret;

  if (!decode->input_state)
    goto not_negotiated;

  if (G_UNLIKELY (!decode->active) ||
      gst_pad_needs_reconfigure (GST_VIDEO_DECODER_SRC_PAD (vdec))) {
    GST_DEBUG_OBJECT (decode, "activating the decoder");
    if (!gst_vaapidecode_update_src_caps (decode))
      goto not_negotiated;

    if (!gst_video_decoder_negotiate (vdec))
      goto not_negotiated;

    GstVaapiPluginBase *const plugin = GST_VAAPI_PLUGIN_BASE (vdec);
    if (!gst_vaapi_plugin_base_set_caps (plugin, NULL, decode->srcpad_caps))
      goto not_negotiated;

    decode->active = TRUE;
  }

  /* Decode current frame */
  for (;;) {
    status = gst_vaapi_decoder_decode (decode->decoder, frame);
    if (status == GST_VAAPI_DECODER_STATUS_ERROR_NO_SURFACE) {
      /* Make sure that there are no decoded frames waiting in the
         output queue. */
      ret = gst_vaapidecode_push_all_decoded_frames (decode);
      if (ret != GST_FLOW_OK)
        goto error_push_all_decoded_frames;

      g_mutex_lock (&decode->surface_ready_mutex);
      if (gst_vaapi_decoder_check_status (decode->decoder) ==
          GST_VAAPI_DECODER_STATUS_ERROR_NO_SURFACE)
        g_cond_wait (&decode->surface_ready, &decode->surface_ready_mutex);
      g_mutex_unlock (&decode->surface_ready_mutex);
      continue;
    }
    if (status != GST_VAAPI_DECODER_STATUS_SUCCESS)
      goto error_decode;
    break;
  }

  /* Note that gst_vaapi_decoder_decode cannot return success without
     completing the decode and pushing all decoded frames into the output
     queue */
  return gst_vaapidecode_push_all_decoded_frames (decode);

  /* ERRORS */
error_push_all_decoded_frames:
  {
    GST_ERROR ("push loop error while decoding %d", ret);
    gst_video_decoder_drop_frame (vdec, frame);
    return ret;
  }
error_decode:
  {
    GST_ERROR ("decode error %d", status);
    switch (status) {
      case GST_VAAPI_DECODER_STATUS_ERROR_UNSUPPORTED_CODEC:
      case GST_VAAPI_DECODER_STATUS_ERROR_UNSUPPORTED_PROFILE:
      case GST_VAAPI_DECODER_STATUS_ERROR_UNSUPPORTED_CHROMA_FORMAT:
        ret = GST_FLOW_NOT_SUPPORTED;
        break;
      default:
        GST_VIDEO_DECODER_ERROR (vdec, 1, STREAM, DECODE, ("Decoding error"),
            ("Decode error %d", status), ret);
        break;
    }
    gst_video_decoder_drop_frame (vdec, frame);
    return ret;
  }
not_negotiated:
  {
    GST_ERROR_OBJECT (decode, "not negotiated");
    ret = GST_FLOW_NOT_NEGOTIATED;
    gst_video_decoder_drop_frame (vdec, frame);
    return ret;
  }
}

#if GST_CHECK_VERSION(1,5,0)
static GstFlowReturn
gst_vaapidecode_drain (GstVideoDecoder * vdec)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);

  if (!decode->decoder)
    return GST_FLOW_NOT_NEGOTIATED;

  return gst_vaapidecode_push_all_decoded_frames (decode);
}
#endif

static gboolean
gst_vaapidecode_internal_flush (GstVideoDecoder * vdec)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);
  GstVaapiDecoderStatus status;

  if (!decode->decoder)
    return TRUE;

  /* If there is something in GstVideoDecoder's output adapter, then
     submit the frame for decoding */
  if (decode->current_frame_size) {
    gst_video_decoder_have_frame (vdec);
    decode->current_frame_size = 0;
  }

  status = gst_vaapi_decoder_flush (decode->decoder);
  if (status != GST_VAAPI_DECODER_STATUS_SUCCESS) {
    GST_WARNING_OBJECT (decode, "failed to flush decoder (status %d)", status);
    return FALSE;
  }

  return TRUE;
}

static GstFlowReturn
gst_vaapidecode_finish (GstVideoDecoder * vdec)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);
  gboolean flushed;
  GstFlowReturn ret;

  if (!decode->decoder)
    return GST_FLOW_OK;

  flushed = gst_vaapidecode_internal_flush (vdec);
  ret = gst_vaapidecode_push_all_decoded_frames (decode);
  if (!flushed)
    return GST_FLOW_ERROR;
  return ret;
}

static gboolean
gst_vaapidecode_decide_allocation (GstVideoDecoder * vdec, GstQuery * query)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);
  GstCaps *caps = NULL;

  gst_query_parse_allocation (query, &caps, NULL);
  decode->has_texture_upload_meta = FALSE;
#if (USE_GLX || USE_EGL)
  decode->has_texture_upload_meta =
      gst_query_find_allocation_meta (query,
      GST_VIDEO_GL_TEXTURE_UPLOAD_META_API_TYPE, NULL) &&
      gst_vaapi_caps_feature_contains (caps,
      GST_VAAPI_CAPS_FEATURE_GL_TEXTURE_UPLOAD_META);
#endif

  return gst_vaapi_plugin_base_decide_allocation (GST_VAAPI_PLUGIN_BASE (vdec),
      query, 0);
}

static inline gboolean
gst_vaapidecode_ensure_display (GstVaapiDecode * decode)
{
  return gst_vaapi_plugin_base_ensure_display (GST_VAAPI_PLUGIN_BASE (decode));
}

static inline guint
gst_vaapi_codec_from_caps (GstCaps * caps)
{
  return gst_vaapi_profile_get_codec (gst_vaapi_profile_from_caps (caps));
}

static gboolean
gst_vaapidecode_create (GstVaapiDecode * decode, GstCaps * caps)
{
  GstVaapiDisplay *dpy;

  if (!gst_vaapidecode_ensure_display (decode))
    return FALSE;
  dpy = GST_VAAPI_PLUGIN_BASE_DISPLAY (decode);

  switch (gst_vaapi_codec_from_caps (caps)) {
    case GST_VAAPI_CODEC_MPEG2:
      decode->decoder = gst_vaapi_decoder_mpeg2_new (dpy, caps);
      break;
    case GST_VAAPI_CODEC_MPEG4:
    case GST_VAAPI_CODEC_H263:
      decode->decoder = gst_vaapi_decoder_mpeg4_new (dpy, caps);
      break;
    case GST_VAAPI_CODEC_H264:
      decode->decoder = gst_vaapi_decoder_h264_new (dpy, caps);

      /* Set the stream buffer alignment for better optimizations */
      if (decode->decoder && caps) {
        GstStructure *const structure = gst_caps_get_structure (caps, 0);
        const gchar *str = NULL;

        if ((str = gst_structure_get_string (structure, "alignment"))) {
          GstVaapiStreamAlignH264 alignment;
          if (g_strcmp0 (str, "au") == 0)
            alignment = GST_VAAPI_STREAM_ALIGN_H264_AU;
          else if (g_strcmp0 (str, "nal") == 0)
            alignment = GST_VAAPI_STREAM_ALIGN_H264_NALU;
          else
            alignment = GST_VAAPI_STREAM_ALIGN_H264_NONE;
          gst_vaapi_decoder_h264_set_alignment (GST_VAAPI_DECODER_H264
              (decode->decoder), alignment);
        }
      }
      break;
#if USE_HEVC_DECODER
    case GST_VAAPI_CODEC_H265:
      decode->decoder = gst_vaapi_decoder_h265_new (dpy, caps);

      /* Set the stream buffer alignment for better optimizations */
      if (decode->decoder && caps) {
        GstStructure *const structure = gst_caps_get_structure (caps, 0);
        const gchar *str = NULL;

        if ((str = gst_structure_get_string (structure, "alignment"))) {
          GstVaapiStreamAlignH265 alignment;
          if (g_strcmp0 (str, "au") == 0)
            alignment = GST_VAAPI_STREAM_ALIGN_H265_AU;
          else if (g_strcmp0 (str, "nal") == 0)
            alignment = GST_VAAPI_STREAM_ALIGN_H265_NALU;
          else
            alignment = GST_VAAPI_STREAM_ALIGN_H265_NONE;
          gst_vaapi_decoder_h265_set_alignment (GST_VAAPI_DECODER_H265
              (decode->decoder), alignment);
        }
      }
      break;
#endif
    case GST_VAAPI_CODEC_WMV3:
    case GST_VAAPI_CODEC_VC1:
      decode->decoder = gst_vaapi_decoder_vc1_new (dpy, caps);
      break;
#if USE_JPEG_DECODER
    case GST_VAAPI_CODEC_JPEG:
      decode->decoder = gst_vaapi_decoder_jpeg_new (dpy, caps);
      break;
#endif
#if USE_VP8_DECODER
    case GST_VAAPI_CODEC_VP8:
      decode->decoder = gst_vaapi_decoder_vp8_new (dpy, caps);
      break;
#endif
#if USE_VP9_DECODER
    case GST_VAAPI_CODEC_VP9:
      decode->decoder = gst_vaapi_decoder_vp9_new (dpy, caps);
      break;
#endif
    default:
      decode->decoder = NULL;
      break;
  }
  if (!decode->decoder)
    return FALSE;

  gst_vaapi_decoder_set_codec_state_changed_func (decode->decoder,
      gst_vaapi_decoder_state_changed, decode);

  decode->decoder_caps = gst_caps_ref (caps);
  return TRUE;
}

static void
gst_vaapidecode_purge (GstVaapiDecode * decode)
{
  GstVaapiDecoderStatus status;

  if (!decode->decoder)
    return;

  status = gst_vaapi_decoder_flush (decode->decoder);
  if (status != GST_VAAPI_DECODER_STATUS_SUCCESS)
    GST_INFO_OBJECT (decode, "failed to flush decoder (status %d)", status);

  /* Purge all decoded frames as we don't need them (e.g. flush and close)
   * Releasing the frames is important, otherwise the frames are not
   * freed. */
  do {
    GstVideoCodecFrame *frame = NULL;

    status =
        gst_vaapi_decoder_get_frame_with_timeout (decode->decoder, &frame, 0);
    if (frame) {
      gst_video_decoder_release_frame (GST_VIDEO_DECODER (decode), frame);
      gst_video_codec_frame_unref (frame);
    }
  } while (status == GST_VAAPI_DECODER_STATUS_SUCCESS);
}

static void
gst_vaapidecode_destroy (GstVaapiDecode * decode)
{
  gst_vaapidecode_purge (decode);

  gst_vaapi_decoder_replace (&decode->decoder, NULL);
  gst_caps_replace (&decode->decoder_caps, NULL);

  decode->active = FALSE;

  gst_vaapidecode_release (gst_object_ref (decode));
}

static gboolean
gst_vaapidecode_reset_full (GstVaapiDecode * decode, GstCaps * caps,
    gboolean hard)
{
  GstVaapiCodec codec;

  /* Reset tracked frame size */
  decode->current_frame_size = 0;

  if (!hard && decode->decoder && decode->decoder_caps) {
    if (gst_caps_is_always_compatible (caps, decode->decoder_caps))
      return TRUE;
    codec = gst_vaapi_codec_from_caps (caps);
    if (codec == gst_vaapi_decoder_get_codec (decode->decoder))
      return TRUE;
  }

  gst_vaapidecode_destroy (decode);
  return gst_vaapidecode_create (decode, caps);
}

static void
gst_vaapidecode_finalize (GObject * object)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (object);

  gst_caps_replace (&decode->sinkpad_caps, NULL);
  gst_caps_replace (&decode->srcpad_caps, NULL);
  gst_caps_replace (&decode->allowed_caps, NULL);

  g_cond_clear (&decode->surface_ready);
  g_mutex_clear (&decode->surface_ready_mutex);

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

static gboolean
gst_vaapidecode_open (GstVideoDecoder * vdec)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);
  GstVaapiDisplay *const old_display = GST_VAAPI_PLUGIN_BASE_DISPLAY (decode);
  gboolean success;

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

  /* Let GstVideoContext ask for a proper display to its neighbours */
  /* Note: steal old display that may be allocated from get_caps()
     so that to retain a reference to it, thus avoiding extra
     initialization steps if we turn out to simply re-use the
     existing (cached) VA display */
  GST_VAAPI_PLUGIN_BASE_DISPLAY (decode) = NULL;
  success = gst_vaapidecode_ensure_display (decode);
  if (old_display)
    gst_vaapi_display_unref (old_display);
  return success;
}

static gboolean
gst_vaapidecode_close (GstVideoDecoder * vdec)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);

  gst_vaapi_decode_input_state_replace (decode, NULL);
  gst_vaapidecode_destroy (decode);
  gst_vaapi_plugin_base_close (GST_VAAPI_PLUGIN_BASE (decode));
  return TRUE;
}

static gboolean
gst_vaapidecode_flush (GstVideoDecoder * vdec)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);

  if (decode->decoder && !gst_vaapidecode_internal_flush (vdec))
    return FALSE;

  /* There could be issues if we avoid the reset_full() while doing
   * seeking: we have to reset the internal state */
  return gst_vaapidecode_reset_full (decode, decode->sinkpad_caps, TRUE);
}

static gboolean
gst_vaapidecode_set_format (GstVideoDecoder * vdec, GstVideoCodecState * state)
{
  GstVaapiPluginBase *const plugin = GST_VAAPI_PLUGIN_BASE (vdec);
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);

  if (!gst_vaapi_decode_input_state_replace (decode, state))
    return TRUE;
  if (!gst_vaapidecode_update_sink_caps (decode, state->caps))
    return FALSE;
  if (!gst_vaapi_plugin_base_set_caps (plugin, decode->sinkpad_caps, NULL))
    return FALSE;
  if (!gst_vaapidecode_reset_full (decode, decode->sinkpad_caps, FALSE))
    return FALSE;

  return TRUE;
}

static GstFlowReturn
gst_vaapidecode_parse_frame (GstVideoDecoder * vdec,
    GstVideoCodecFrame * frame, GstAdapter * adapter, gboolean at_eos)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);
  GstVaapiDecoderStatus status;
  GstFlowReturn ret;
  guint got_unit_size;
  gboolean got_frame;

  status = gst_vaapi_decoder_parse (decode->decoder, frame,
      adapter, at_eos, &got_unit_size, &got_frame);

  switch (status) {
    case GST_VAAPI_DECODER_STATUS_SUCCESS:
      if (got_unit_size > 0) {
        gst_video_decoder_add_to_frame (vdec, got_unit_size);
        decode->current_frame_size += got_unit_size;
      }
      if (got_frame) {
        ret = gst_video_decoder_have_frame (vdec);
        decode->current_frame_size = 0;
      } else
        ret = GST_VAAPI_DECODE_FLOW_PARSE_DATA;
      break;
    case GST_VAAPI_DECODER_STATUS_ERROR_NO_DATA:
      ret = GST_VIDEO_DECODER_FLOW_NEED_DATA;
      break;
    case GST_VAAPI_DECODER_STATUS_ERROR_UNSUPPORTED_CODEC:
    case GST_VAAPI_DECODER_STATUS_ERROR_UNSUPPORTED_PROFILE:
    case GST_VAAPI_DECODER_STATUS_ERROR_UNSUPPORTED_CHROMA_FORMAT:
      GST_WARNING ("parse error %d", status);
      ret = GST_FLOW_NOT_SUPPORTED;
      decode->current_frame_size = 0;
      break;
    default:
      GST_ERROR ("parse error %d", status);
      ret = GST_FLOW_EOS;
      decode->current_frame_size = 0;
      break;
  }
  return ret;
}

static GstFlowReturn
gst_vaapidecode_parse (GstVideoDecoder * vdec,
    GstVideoCodecFrame * frame, GstAdapter * adapter, gboolean at_eos)
{
  GstFlowReturn ret;

  do {
    ret = gst_vaapidecode_parse_frame (vdec, frame, adapter, at_eos);
  } while (ret == GST_VAAPI_DECODE_FLOW_PARSE_DATA);
  return ret;
}

static void
gst_vaapidecode_class_init (GstVaapiDecodeClass * klass)
{
  GObjectClass *const object_class = G_OBJECT_CLASS (klass);
  GstElementClass *const element_class = GST_ELEMENT_CLASS (klass);
  GstVideoDecoderClass *const vdec_class = GST_VIDEO_DECODER_CLASS (klass);
  GstPadTemplate *pad_template;

  GST_DEBUG_CATEGORY_INIT (gst_debug_vaapidecode,
      GST_PLUGIN_NAME, 0, GST_PLUGIN_DESC);

  gst_vaapi_plugin_base_class_init (GST_VAAPI_PLUGIN_BASE_CLASS (klass));

  object_class->finalize = gst_vaapidecode_finalize;

  vdec_class->open = GST_DEBUG_FUNCPTR (gst_vaapidecode_open);
  vdec_class->close = GST_DEBUG_FUNCPTR (gst_vaapidecode_close);
  vdec_class->set_format = GST_DEBUG_FUNCPTR (gst_vaapidecode_set_format);
  vdec_class->flush = GST_DEBUG_FUNCPTR (gst_vaapidecode_flush);
  vdec_class->parse = GST_DEBUG_FUNCPTR (gst_vaapidecode_parse);
  vdec_class->handle_frame = GST_DEBUG_FUNCPTR (gst_vaapidecode_handle_frame);
  vdec_class->finish = GST_DEBUG_FUNCPTR (gst_vaapidecode_finish);
#if GST_CHECK_VERSION(1,5,0)
  vdec_class->drain = GST_DEBUG_FUNCPTR (gst_vaapidecode_drain);
#endif
  vdec_class->decide_allocation =
      GST_DEBUG_FUNCPTR (gst_vaapidecode_decide_allocation);
#if GST_CHECK_VERSION(1,4,0)
  vdec_class->src_query = GST_DEBUG_FUNCPTR (gst_vaapidecode_src_query);
  vdec_class->sink_query = GST_DEBUG_FUNCPTR (gst_vaapidecode_sink_query);
#endif

  gst_element_class_set_static_metadata (element_class,
      "VA-API decoder",
      "Codec/Decoder/Video",
      GST_PLUGIN_DESC,
      "Gwenole Beauchesne <gwenole.beauchesne@intel.com>, "
      "Halley Zhao <halley.zhao@intel.com>, "
      "Sreerenj Balachandran <sreerenj.balachandran@intel.com>, "
      "Wind Yuan <feng.yuan@intel.com>");

  /* sink pad */
  pad_template = gst_static_pad_template_get (&gst_vaapidecode_sink_factory);
  gst_element_class_add_pad_template (element_class, pad_template);

  /* src pad */
  pad_template = gst_static_pad_template_get (&gst_vaapidecode_src_factory);
  gst_element_class_add_pad_template (element_class, pad_template);
}

static gboolean
gst_vaapidecode_ensure_allowed_caps (GstVaapiDecode * decode)
{
  GstCaps *caps, *allowed_caps;
  GArray *profiles;
  guint i;

  profiles =
      gst_vaapi_display_get_decode_profiles (GST_VAAPI_PLUGIN_BASE_DISPLAY
      (decode));
  if (!profiles)
    goto error_no_profiles;

  allowed_caps = gst_caps_new_empty ();
  if (!allowed_caps)
    goto error_no_memory;

  for (i = 0; i < profiles->len; i++) {
    const GstVaapiProfile profile =
        g_array_index (profiles, GstVaapiProfile, i);
    const gchar *media_type_name;
    const gchar *profile_name;
    GstStructure *structure;

    media_type_name = gst_vaapi_profile_get_media_type_name (profile);
    if (!media_type_name)
      continue;

    caps = gst_caps_from_string (media_type_name);
    if (!caps)
      continue;
    structure = gst_caps_get_structure (caps, 0);

    profile_name = gst_vaapi_profile_get_name (profile);
    if (profile_name)
      gst_structure_set (structure, "profile", G_TYPE_STRING,
          profile_name, NULL);

    allowed_caps = gst_caps_merge (allowed_caps, caps);
  }
  decode->allowed_caps = gst_caps_simplify (allowed_caps);

  g_array_unref (profiles);
  return TRUE;

  /* ERRORS */
error_no_profiles:
  {
    GST_ERROR ("failed to retrieve VA decode profiles");
    return FALSE;
  }
error_no_memory:
  {
    GST_ERROR ("failed to allocate allowed-caps set");
    g_array_unref (profiles);
    return FALSE;
  }
}

static GstCaps *
gst_vaapidecode_get_caps (GstPad * pad)
{
  GstVaapiDecode *const decode = GST_VAAPIDECODE (GST_OBJECT_PARENT (pad));

  if (decode->allowed_caps)
    goto bail;

  /* if we haven't a display yet, return our pad's template caps */
  if (!GST_VAAPI_PLUGIN_BASE_DISPLAY (decode))
    return gst_pad_get_pad_template_caps (pad);

  /* if the allowed caps calculation fails, return an empty caps, so
   * the auto-plug can try other decoder */
  if (!gst_vaapidecode_ensure_allowed_caps (decode))
    return gst_caps_new_empty ();

bail:
  return gst_caps_ref (decode->allowed_caps);
}

#if !GST_CHECK_VERSION(1,4,0)
static gboolean
gst_vaapidecode_query (GstPad * pad, GstObject * parent, GstQuery * query)
{
  GstVaapiDecode *const decode =
      GST_VAAPIDECODE (gst_pad_get_parent_element (pad));
  GstVideoDecoder *const vdec = GST_VIDEO_DECODER (decode);
  gboolean res;

  GST_INFO_OBJECT (decode, "query type %s on %s pad",
      GST_QUERY_TYPE_NAME (query), GST_PAD_IS_SINK (pad) ? "sink" : "src");

  if (GST_PAD_IS_SINK (pad))
    res = gst_vaapidecode_sink_query (vdec, query);
  else
    res = gst_vaapidecode_src_query (vdec, query);

  gst_object_unref (vdec);
  return res;
}
#endif

static gboolean
gst_vaapidecode_sink_query (GstVideoDecoder * vdec, GstQuery * query)
{
  gboolean ret = TRUE;
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);
  GstVaapiPluginBase *const plugin = GST_VAAPI_PLUGIN_BASE (decode);

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_CAPS:{
      GstCaps *caps, *filter = NULL;
      GstPad *pad = GST_VIDEO_DECODER_SINK_PAD (vdec);

      gst_query_parse_caps (query, &filter);
      caps = gst_vaapidecode_get_caps (pad);

      if (filter) {
        GstCaps *tmp = caps;
        caps = gst_caps_intersect_full (filter, tmp, GST_CAPS_INTERSECT_FIRST);
        gst_caps_unref (tmp);
      }

      gst_query_set_caps_result (query, caps);
      gst_caps_unref (caps);
      break;
    }
    case GST_QUERY_CONTEXT:{
      ret = gst_vaapi_handle_context_query (query, plugin->display);
      break;
    }
    default:{
#if GST_CHECK_VERSION(1,4,0)
      ret = GST_VIDEO_DECODER_CLASS (gst_vaapidecode_parent_class)->sink_query
          (vdec, query);
#else
      GstPad *pad = GST_VIDEO_DECODER_SINK_PAD (vdec);
      GstObject *parent = gst_pad_get_parent (pad);
      ret = plugin->sinkpad_query (pad, parent, query);
      if (parent)
        gst_object_unref (parent);
#endif
      break;
    }
  }

  return ret;
}

static gboolean
gst_vaapidecode_src_query (GstVideoDecoder * vdec, GstQuery * query)
{
  gboolean ret = TRUE;
  GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);
  GstVaapiPluginBase *const plugin = GST_VAAPI_PLUGIN_BASE (decode);

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_CAPS:{
      GstCaps *caps, *filter = NULL;
      GstPad *pad = GST_VIDEO_DECODER_SRC_PAD (vdec);

      gst_query_parse_caps (query, &filter);
      caps = gst_pad_get_pad_template_caps (pad);

      if (filter) {
        GstCaps *tmp = caps;
        caps = gst_caps_intersect_full (filter, tmp, GST_CAPS_INTERSECT_FIRST);
        gst_caps_unref (tmp);
      }

      gst_query_set_caps_result (query, caps);
      gst_caps_unref (caps);
      break;
    }
    case GST_QUERY_CONTEXT:{
      ret = gst_vaapi_handle_context_query (query, plugin->display);
      break;
    }
    default:{
#if GST_CHECK_VERSION(1,4,0)
      ret = GST_VIDEO_DECODER_CLASS (gst_vaapidecode_parent_class)->src_query
          (vdec, query);
#else
      GstPad *pad = GST_VIDEO_DECODER_SRC_PAD (vdec);
      GstObject *parent = gst_pad_get_parent (pad);
      ret = plugin->srcpad_query (pad, parent, query);
      if (parent)
        gst_object_unref (parent);
#endif
      break;
    }
  }

  return ret;
}

static void
gst_vaapidecode_init (GstVaapiDecode * decode)
{
  GstVideoDecoder *const vdec = GST_VIDEO_DECODER (decode);

  gst_vaapi_plugin_base_init (GST_VAAPI_PLUGIN_BASE (decode), GST_CAT_DEFAULT);

  decode->decoder = NULL;
  decode->decoder_caps = NULL;
  decode->allowed_caps = NULL;

  g_mutex_init (&decode->surface_ready_mutex);
  g_cond_init (&decode->surface_ready);

  gst_video_decoder_set_packetized (vdec, FALSE);

#if !GST_CHECK_VERSION(1,4,0)
  /* Pad through which data comes in to the element */
  GstPad *pad = GST_VAAPI_PLUGIN_BASE_SINK_PAD (decode);
  gst_pad_set_query_function (pad, GST_DEBUG_FUNCPTR (gst_vaapidecode_query));

  /* Pad through which data goes out of the element */
  pad = GST_VAAPI_PLUGIN_BASE_SRC_PAD (decode);
  gst_pad_set_query_function (pad, GST_DEBUG_FUNCPTR (gst_vaapidecode_query));
#endif
}