static gboolean
gst_vaapi_surface_create_from_buffer_proxy (GstVaapiSurface * surface,
    GstVaapiBufferProxy * proxy, const GstVideoInfo * vip)
{
#if VA_CHECK_VERSION (0,36,0)
  GstVaapiDisplay *const display = GST_VAAPI_OBJECT_DISPLAY (surface);
  GstVideoFormat format;
  VASurfaceID surface_id;
  VAStatus status;
  guint chroma_type, va_chroma_format;
  const VAImageFormat *va_format;
  VASurfaceAttrib attribs[2], *attrib;
  VASurfaceAttribExternalBuffers extbuf;
  unsigned long extbuf_handle;
  guint i, width, height;

  format = GST_VIDEO_INFO_FORMAT (vip);
  width = GST_VIDEO_INFO_WIDTH (vip);
  height = GST_VIDEO_INFO_HEIGHT (vip);

  gst_vaapi_buffer_proxy_replace (&surface->extbuf_proxy, proxy);

  va_format = gst_vaapi_video_format_to_va_format (format);
  if (!va_format)
    goto error_unsupported_format;

  chroma_type = gst_vaapi_video_format_get_chroma_type (format);
  if (!chroma_type)
    goto error_unsupported_format;

  va_chroma_format = from_GstVaapiChromaType (chroma_type);
  if (!va_chroma_format)
    goto error_unsupported_format;

  extbuf_handle = GST_VAAPI_BUFFER_PROXY_HANDLE (proxy);
  extbuf.pixel_format = va_format->fourcc;
  extbuf.width = width;
  extbuf.height = height;
  extbuf.data_size = GST_VAAPI_BUFFER_PROXY_SIZE (proxy);
  extbuf.num_planes = GST_VIDEO_INFO_N_PLANES (vip);
  for (i = 0; i < extbuf.num_planes; i++) {
    extbuf.pitches[i] = GST_VIDEO_INFO_PLANE_STRIDE (vip, i);
    extbuf.offsets[i] = GST_VIDEO_INFO_PLANE_OFFSET (vip, i);
  }
  extbuf.buffers = &extbuf_handle;
  extbuf.num_buffers = 1;
  extbuf.flags = 0;
  extbuf.private_data = NULL;

  attrib = attribs;
  attrib->type = VASurfaceAttribExternalBufferDescriptor;
  attrib->flags = VA_SURFACE_ATTRIB_SETTABLE;
  attrib->value.type = VAGenericValueTypePointer;
  attrib->value.value.p = &extbuf;
  attrib++;
  attrib->type = VASurfaceAttribMemoryType;
  attrib->flags = VA_SURFACE_ATTRIB_SETTABLE;
  attrib->value.type = VAGenericValueTypeInteger;
  attrib->value.value.i =
      from_GstVaapiBufferMemoryType (GST_VAAPI_BUFFER_PROXY_TYPE (proxy));
  attrib++;

  GST_VAAPI_DISPLAY_LOCK (display);
  status = vaCreateSurfaces (GST_VAAPI_DISPLAY_VADISPLAY (display),
      va_chroma_format, width, height, &surface_id, 1, attribs,
      attrib - attribs);
  GST_VAAPI_DISPLAY_UNLOCK (display);
  if (!vaapi_check_status (status, "vaCreateSurfaces()"))
    return FALSE;

  surface->format = format;
  surface->chroma_type = chroma_type;
  surface->width = width;
  surface->height = height;

  GST_DEBUG ("surface %" GST_VAAPI_ID_FORMAT, GST_VAAPI_ID_ARGS (surface_id));
  GST_VAAPI_OBJECT_ID (surface) = surface_id;
  return TRUE;

  /* ERRORS */
error_unsupported_format:
  GST_ERROR ("unsupported format %s",
      gst_vaapi_video_format_to_string (format));
  return FALSE;
#else
  return FALSE;
#endif
}

static gboolean
default_can_save_uri (const gchar * uri)
{
  GST_ERROR ("No 'can_save_uri' vmethod implementation");
  return FALSE;
}

static GstVaapiDecoderStatus
decode_scan (GstVaapiDecoderJpeg * decoder, GstJpegSegment * seg)
{
  GstVaapiDecoderJpegPrivate *const priv = &decoder->priv;
  GstVaapiPicture *const picture = priv->current_picture;
  GstVaapiSlice *slice;
  VASliceParameterBufferJPEGBaseline *slice_param;
  GstJpegScanHdr scan_hdr;
  guint scan_hdr_size, scan_data_size;
  guint i, h_max, v_max, mcu_width, mcu_height;

  if (!VALID_STATE (decoder, GOT_SOF))
    return GST_VAAPI_DECODER_STATUS_SUCCESS;

  scan_hdr_size = (seg->data[seg->offset] << 8) | seg->data[seg->offset + 1];
  scan_data_size = seg->size - scan_hdr_size;

  memset (&scan_hdr, 0, sizeof (scan_hdr));
  if (!gst_jpeg_segment_parse_scan_header (seg, &scan_hdr)) {
    GST_ERROR ("failed to parse scan header");
    return GST_VAAPI_DECODER_STATUS_ERROR_BITSTREAM_PARSER;
  }

  slice = GST_VAAPI_SLICE_NEW (JPEGBaseline, decoder,
      seg->data + seg->offset + scan_hdr_size, scan_data_size);
  if (!slice) {
    GST_ERROR ("failed to allocate slice");
    return GST_VAAPI_DECODER_STATUS_ERROR_ALLOCATION_FAILED;
  }
  gst_vaapi_picture_add_slice (picture, slice);

  if (!VALID_STATE (decoder, GOT_HUF_TABLE))
    gst_jpeg_get_default_huffman_tables (&priv->huf_tables);

  // Update VA Huffman table if it changed for this scan
  if (huffman_tables_updated (&priv->huf_tables)) {
    slice->huf_table = GST_VAAPI_HUFFMAN_TABLE_NEW (JPEGBaseline, decoder);
    if (!slice->huf_table) {
      GST_ERROR ("failed to allocate Huffman tables");
      huffman_tables_reset (&priv->huf_tables);
      return GST_VAAPI_DECODER_STATUS_ERROR_ALLOCATION_FAILED;
    }
    fill_huffman_table (slice->huf_table, &priv->huf_tables);
    huffman_tables_reset (&priv->huf_tables);
  }

  slice_param = slice->param;
  slice_param->num_components = scan_hdr.num_components;
  for (i = 0; i < scan_hdr.num_components; i++) {
    slice_param->components[i].component_selector =
        scan_hdr.components[i].component_selector;
    slice_param->components[i].dc_table_selector =
        scan_hdr.components[i].dc_selector;
    slice_param->components[i].ac_table_selector =
        scan_hdr.components[i].ac_selector;
  }
  slice_param->restart_interval = priv->mcu_restart;
  slice_param->slice_horizontal_position = 0;
  slice_param->slice_vertical_position = 0;

  get_max_sampling_factors (&priv->frame_hdr, &h_max, &v_max);
  mcu_width = 8 * h_max;
  mcu_height = 8 * v_max;

  if (scan_hdr.num_components == 1) {   // Non-interleaved
    const guint Csj = slice_param->components[0].component_selector;
    const GstJpegFrameComponent *const fcp =
        get_component (&priv->frame_hdr, Csj);

    if (!fcp || fcp->horizontal_factor == 0 || fcp->vertical_factor == 0) {
      GST_ERROR ("failed to validate image component %u", Csj);
      return GST_VAAPI_DECODER_STATUS_ERROR_INVALID_PARAMETER;
    }
    mcu_width /= fcp->horizontal_factor;
    mcu_height /= fcp->vertical_factor;
  }
  slice_param->num_mcus =
      ((priv->frame_hdr.width + mcu_width - 1) / mcu_width) *
      ((priv->frame_hdr.height + mcu_height - 1) / mcu_height);

  priv->decoder_state |= GST_JPEG_VIDEO_STATE_GOT_SOS;
  return GST_VAAPI_DECODER_STATUS_SUCCESS;
}

//.........这里部分代码省略.........
  size -= 2;

  GST_DEBUG ("  MXF version = %u.%u", pack->major_version, pack->minor_version);

  pack->kag_size = GST_READ_UINT32_BE (data);
  data += 4;
  size -= 4;

  GST_DEBUG ("  KAG size = %u", pack->kag_size);

  pack->this_partition = GST_READ_UINT64_BE (data);
  data += 8;
  size -= 8;

  GST_DEBUG ("  this partition offset = %" G_GUINT64_FORMAT,
      pack->this_partition);

  pack->prev_partition = GST_READ_UINT64_BE (data);
  data += 8;
  size -= 8;

  GST_DEBUG ("  previous partition offset = %" G_GUINT64_FORMAT,
      pack->prev_partition);

  pack->footer_partition = GST_READ_UINT64_BE (data);
  data += 8;
  size -= 8;

  GST_DEBUG ("  footer partition offset = %" G_GUINT64_FORMAT,
      pack->footer_partition);

  pack->header_byte_count = GST_READ_UINT64_BE (data);
  data += 8;
  size -= 8;

  GST_DEBUG ("  header byte count = %" G_GUINT64_FORMAT,
      pack->header_byte_count);

  pack->index_byte_count = GST_READ_UINT64_BE (data);
  data += 8;
  size -= 8;

  pack->index_sid = GST_READ_UINT32_BE (data);
  data += 4;
  size -= 4;

  GST_DEBUG ("  index sid = %u, size = %" G_GUINT64_FORMAT, pack->index_sid,
      pack->index_byte_count);

  pack->body_offset = GST_READ_UINT64_BE (data);
  data += 8;
  size -= 8;

  pack->body_sid = GST_READ_UINT32_BE (data);
  data += 4;
  size -= 4;

  GST_DEBUG ("  body sid = %u, offset = %" G_GUINT64_FORMAT, pack->body_sid,
      pack->body_offset);

  memcpy (&pack->operational_pattern, data, 16);
  data += 16;
  size -= 16;

  GST_DEBUG ("  operational pattern = %s",
      mxf_ul_to_string (&pack->operational_pattern, str));

  pack->n_essence_containers = GST_READ_UINT32_BE (data);
  data += 4;
  size -= 4;

  GST_DEBUG ("  number of essence containers = %u", pack->n_essence_containers);

  if (GST_READ_UINT32_BE (data) != 16)
    goto error;
  data += 4;
  size -= 4;

  if (size < 16 * pack->n_essence_containers)
    goto error;

  if (pack->n_essence_containers) {
    pack->essence_containers = g_new (MXFUL, pack->n_essence_containers);
    for (i = 0; i < pack->n_essence_containers; i++) {
      memcpy (&pack->essence_containers[i], data + i * 16, 16);
      GST_DEBUG ("  essence container %u = %s", i,
          mxf_ul_to_string (&pack->essence_containers[i], str));
    }
  }

  pack->valid = TRUE;

  return TRUE;

error:
  GST_ERROR ("Invalid partition pack");

  mxf_partition_pack_reset (pack);
  return FALSE;
}

static GstV4l2MemoryGroup *
gst_v4l2_memory_group_new (GstV4l2Allocator * allocator, guint32 index)
{
  GstV4l2Object *obj = allocator->obj;
  guint32 memory = allocator->memory;
  struct v4l2_format *format = &obj->format;
  GstV4l2MemoryGroup *group;
  gsize img_size, buf_size;

  group = g_slice_new0 (GstV4l2MemoryGroup);

  group->buffer.type = format->type;
  group->buffer.index = index;
  group->buffer.memory = memory;

  if (V4L2_TYPE_IS_MULTIPLANAR (format->type)) {
    group->n_mem = group->buffer.length = format->fmt.pix_mp.num_planes;
    group->buffer.m.planes = group->planes;
  } else {
    group->n_mem = 1;
  }

  if (obj->ioctl (obj->video_fd, VIDIOC_QUERYBUF, &group->buffer) < 0)
    goto querybuf_failed;

  if (group->buffer.index != index) {
    GST_ERROR_OBJECT (allocator, "Buffer index returned by VIDIOC_QUERYBUF "
        "didn't match, this indicate the presence of a bug in your driver or "
        "libv4l2");
    g_slice_free (GstV4l2MemoryGroup, group);
    return NULL;
  }

  /* Check that provided size matches the format we have negotiation. Failing
   * there usually means a driver of libv4l bug. */
  if (V4L2_TYPE_IS_MULTIPLANAR (obj->type)) {
    gint i;

    for (i = 0; i < group->n_mem; i++) {
      img_size = obj->format.fmt.pix_mp.plane_fmt[i].sizeimage;
      buf_size = group->planes[i].length;
      if (buf_size < img_size)
        goto buffer_too_short;
    }
  } else {
    img_size = obj->format.fmt.pix.sizeimage;
    buf_size = group->buffer.length;
    if (buf_size < img_size)
      goto buffer_too_short;
  }

  /* We save non planar buffer information into the multi-planar plane array
   * to avoid duplicating the code later */
  if (!V4L2_TYPE_IS_MULTIPLANAR (format->type)) {
    group->planes[0].bytesused = group->buffer.bytesused;
    group->planes[0].length = group->buffer.length;
    group->planes[0].data_offset = 0;
    g_assert (sizeof (group->planes[0].m) == sizeof (group->buffer.m));
    memcpy (&group->planes[0].m, &group->buffer.m, sizeof (group->buffer.m));
  }

  GST_LOG_OBJECT (allocator, "Got %s buffer", memory_type_to_str (memory));
  GST_LOG_OBJECT (allocator, "  index:     %u", group->buffer.index);
  GST_LOG_OBJECT (allocator, "  type:      %d", group->buffer.type);
  GST_LOG_OBJECT (allocator, "  flags:     %08x", group->buffer.flags);
  GST_LOG_OBJECT (allocator, "  field:     %d", group->buffer.field);
  GST_LOG_OBJECT (allocator, "  memory:    %d", group->buffer.memory);
  GST_LOG_OBJECT (allocator, "  planes:    %d", group->n_mem);

#ifndef GST_DISABLE_GST_DEBUG
  if (memory == V4L2_MEMORY_MMAP) {
    gint i;
    for (i = 0; i < group->n_mem; i++) {
      GST_LOG_OBJECT (allocator,
          "  [%u] bytesused: %u, length: %u, offset: %u", i,
          group->planes[i].bytesused, group->planes[i].length,
          group->planes[i].data_offset);
      GST_LOG_OBJECT (allocator, "  [%u] MMAP offset:  %u", i,
          group->planes[i].m.mem_offset);
    }
  }
#endif

  return group;

querybuf_failed:
  {
    GST_ERROR ("error querying buffer %d: %s", index, g_strerror (errno));
    goto failed;
  }
buffer_too_short:
  {
    GST_ERROR ("buffer size %" G_GSIZE_FORMAT
        " is smaller then negotiated size %" G_GSIZE_FORMAT
        ", this is usually the result of a bug in the v4l2 driver or libv4l.",
        buf_size, img_size);
    goto failed;
  }
failed:
  gst_v4l2_memory_group_free (group);
//.........这里部分代码省略.........

static GstFlowReturn
gst_base_video_decoder_drain (GstBaseVideoDecoder * dec, gboolean at_eos)
{
  GstBaseVideoDecoderClass *klass;
  GstBaseVideoDecoderScanResult res;
  guint size;

  klass = GST_BASE_VIDEO_DECODER_GET_CLASS (dec);

  if (gst_adapter_available (dec->input_adapter) == 0)
    return GST_FLOW_OK;

lost_sync:
  if (!dec->have_sync) {
    gint n, m;

    GST_DEBUG ("no sync, scanning");

    n = gst_adapter_available (dec->input_adapter);
    m = klass->scan_for_sync (dec, dec->input_adapter);
    if (m == -1) {
      gst_object_unref (dec);
      return GST_FLOW_OK;
    }

    if (m < 0) {
      g_warning ("subclass returned negative scan %d", m);
    }

    if (m >= n) {
      GST_ERROR ("subclass scanned past end %d >= %d", m, n);
    }

    gst_adapter_flush (dec->input_adapter, m);

    if (m < n) {
      GST_DEBUG ("found possible sync after %d bytes (of %d)", m, n);
      /* this is only "maybe" sync */
      dec->have_sync = TRUE;
    }

    if (!dec->have_sync) {
      return GST_FLOW_OK;
    }
  }

  res = klass->scan_for_packet_end (dec, dec->input_adapter, &size, at_eos);
  while (res == GST_BASE_VIDEO_DECODER_SCAN_RESULT_OK) {
    GstBuffer *buf;
    GstFlowReturn ret;

    GST_DEBUG ("Packet size: %u", size);
    if (size > gst_adapter_available (dec->input_adapter))
      return GST_FLOW_OK;

    buf = gst_adapter_take_buffer (dec->input_adapter, size);

    dec->prev_buf_offset = dec->current_buf_offset;
    dec->current_buf_offset = dec->input_offset -
        gst_adapter_available (dec->input_adapter);

    ret = klass->parse_data (dec, buf, at_eos);
    if (ret != GST_FLOW_OK)
      return ret;

    res = klass->scan_for_packet_end (dec, dec->input_adapter, &size, at_eos);
  }

  switch (res) {
    case GST_BASE_VIDEO_DECODER_SCAN_RESULT_LOST_SYNC:
      dec->have_sync = FALSE;
      goto lost_sync;

    case GST_BASE_VIDEO_DECODER_SCAN_RESULT_NEED_DATA:
      return GST_FLOW_OK;

    default:
      GST_ERROR_OBJECT (dec, "Subclass returned invalid scan result");
      return GST_FLOW_ERROR;
  }
}

//.........这里部分代码省略.........
  GST_DEBUG ("Setting pipeline to PLAYING");
  ASSERT_OBJECT_REFCOUNT (source1, "source1", 1);

  fail_if (gst_element_set_state (GST_ELEMENT (pipeline),
          GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE);

  GST_DEBUG ("Let's poll the bus");

  while (carry_on) {
    message = gst_bus_poll (bus, GST_MESSAGE_ANY, GST_SECOND / 2);
    if (message) {
      switch (GST_MESSAGE_TYPE (message)) {
        case GST_MESSAGE_EOS:
          /* we should check if we really finished here */
          GST_WARNING ("Got an EOS");
          carry_on = FALSE;
          break;
        case GST_MESSAGE_SEGMENT_START:
        case GST_MESSAGE_SEGMENT_DONE:
          /* We shouldn't see any segement messages, since we didn't do a segment seek */
          GST_WARNING ("Saw a Segment start/stop");
          fail_if (TRUE);
          break;
        case GST_MESSAGE_ERROR:
          GST_WARNING ("Saw an ERROR");
          fail_if (TRUE);
        default:
          break;
      }
      gst_mini_object_unref (GST_MINI_OBJECT (message));
    }
  }

  GST_DEBUG ("Setting pipeline to NULL");

  fail_if (gst_element_set_state (GST_ELEMENT (pipeline),
          GST_STATE_READY) == GST_STATE_CHANGE_FAILURE);

  fail_if (collect->expected_segments != NULL);

  GST_DEBUG ("Resetted pipeline to READY");

  /* Expected segments */
  collect->expected_segments = g_list_append (collect->expected_segments,
      segment_new (1.0, GST_FORMAT_TIME, 5 * GST_SECOND, 6 * GST_SECOND, 0));
  collect->expected_segments = g_list_append (collect->expected_segments,
      segment_new (1.0, GST_FORMAT_TIME,
          2 * GST_SECOND, 3 * GST_SECOND, 1 * GST_SECOND));
  collect->gotsegment = FALSE;


  GST_DEBUG ("Setting pipeline to PLAYING again");

  fail_if (gst_element_set_state (GST_ELEMENT (pipeline),
          GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE);

  carry_on = TRUE;

  GST_DEBUG ("Let's poll the bus AGAIN");

  while (carry_on) {
    message = gst_bus_poll (bus, GST_MESSAGE_ANY, GST_SECOND / 2);
    if (message) {
      switch (GST_MESSAGE_TYPE (message)) {
        case GST_MESSAGE_EOS:
          /* we should check if we really finished here */
          carry_on = FALSE;
          break;
        case GST_MESSAGE_SEGMENT_START:
        case GST_MESSAGE_SEGMENT_DONE:
          /* We shouldn't see any segement messages, since we didn't do a segment seek */
          GST_WARNING ("Saw a Segment start/stop");
          fail_if (TRUE);
          break;
        case GST_MESSAGE_ERROR:
          GST_ERROR ("Saw an ERROR");
          fail_if (TRUE);
        default:
          break;
      }
      gst_mini_object_unref (GST_MINI_OBJECT (message));
    } else {
      GST_DEBUG ("bus_poll responded, but there wasn't any message...");
    }
  }

  fail_if (collect->expected_segments != NULL);

  gst_object_unref (GST_OBJECT (sinkpad));

  fail_if (gst_element_set_state (GST_ELEMENT (pipeline),
          GST_STATE_NULL) == GST_STATE_CHANGE_FAILURE);

  ASSERT_OBJECT_REFCOUNT_BETWEEN (pipeline, "main pipeline", 1, 2);
  gst_object_unref (pipeline);
  ASSERT_OBJECT_REFCOUNT_BETWEEN (bus, "main bus", 1, 2);
  gst_object_unref (bus);

  g_free (collect);
}

static gboolean
read_one (GstPluginLoader * l)
{
  guint64 magic;
  guint32 to_read, packet_len, tag;
  guint8 *in;
  gint res;

  to_read = HEADER_SIZE;
  in = l->rx_buf;
  do {
    res = read (l->fd_r.fd, in, to_read);
    if (G_UNLIKELY (res < 0)) {
      if (errno == EAGAIN || errno == EINTR)
        continue;
      GST_LOG ("Failed reading packet header");
      return FALSE;
    }
    to_read -= res;
    in += res;
  } while (to_read > 0);

  magic = GST_READ_UINT32_BE (l->rx_buf + 8);
  if (magic != HEADER_MAGIC) {
    GST_WARNING
        ("Invalid packet (bad magic number) received from plugin scanner subprocess");
    return FALSE;
  }

  packet_len = GST_READ_UINT32_BE (l->rx_buf + 4);
  if (packet_len + HEADER_SIZE > BUF_MAX_SIZE) {
    GST_WARNING
        ("Received excessively large packet for plugin scanner subprocess");
    return FALSE;
  }
  tag = GST_READ_UINT24_BE (l->rx_buf + 1);

  if (packet_len > 0) {
    if (packet_len + HEADER_SIZE >= l->rx_buf_size) {
      GST_LOG ("Expanding rx buf from %d to %d",
          l->rx_buf_size, packet_len + HEADER_SIZE + BUF_GROW_EXTRA);
      l->rx_buf_size = packet_len + HEADER_SIZE + BUF_GROW_EXTRA;
      l->rx_buf = g_realloc (l->rx_buf, l->rx_buf_size);
    }

    in = l->rx_buf + HEADER_SIZE;
    to_read = packet_len;
    do {
      res = read (l->fd_r.fd, in, to_read);
      if (G_UNLIKELY (res < 0)) {
        if (errno == EAGAIN || errno == EINTR)
          continue;
        GST_ERROR ("Packet payload read failed");
        return FALSE;
      }
      to_read -= res;
      in += res;
    } while (to_read > 0);
  } else {
    GST_LOG ("No payload to read for 0 length packet type %d tag %u",
        l->rx_buf[0], tag);
  }

  return handle_rx_packet (l, l->rx_buf[0], tag,
      l->rx_buf + HEADER_SIZE, packet_len);
}

//.........这里部分代码省略.........
      info->offset[0] = 0;
      info->offset[1] = info->stride[0] * height;
      info->offset[2] = info->offset[1] + info->stride[1] * height;
      /* simplification of ROUNDUP4(w)*h + 2*((ROUNDUP16(w)/4)*h */
      break;
    case GST_VIDEO_FORMAT_Y42B:
      info->stride[0] = GST_ROUND_UP_4 (width);
      info->stride[1] = GST_ROUND_UP_8 (width) / 2;
      info->stride[2] = info->stride[1];
      info->offset[0] = 0;
      info->offset[1] = info->stride[0] * height;
      info->offset[2] = info->offset[1] + info->stride[1] * height;
      /* simplification of ROUNDUP4(w)*h + 2*(ROUNDUP8(w)/2)*h */
      break;
    case GST_VIDEO_FORMAT_Y444:
      info->stride[0] = GST_ROUND_UP_4 (width);
      info->stride[1] = info->stride[0];
      info->stride[2] = info->stride[0];
      info->offset[0] = 0;
      info->offset[1] = info->stride[0] * height;
      info->offset[2] = info->offset[1] * 2;
      break;
    case GST_VIDEO_FORMAT_NV12:
    case GST_VIDEO_FORMAT_NV21:
      info->stride[0] = GST_ROUND_UP_4 (width);
      info->stride[1] = info->stride[0];
      info->offset[0] = 0;
      info->offset[1] = info->stride[0] * GST_ROUND_UP_2 (height);
      break;
    case GST_VIDEO_FORMAT_A420:
      info->stride[0] = GST_ROUND_UP_4 (width);
      info->stride[1] = GST_ROUND_UP_4 (GST_ROUND_UP_2 (width) / 2);
      info->stride[2] = info->stride[1];
      info->stride[3] = info->stride[0];
      info->offset[0] = 0;
      info->offset[1] = info->stride[0] * GST_ROUND_UP_2 (height);
      info->offset[2] = info->offset[1] +
          info->stride[1] * (GST_ROUND_UP_2 (height) / 2);
      info->offset[3] = info->offset[2] +
          info->stride[2] * (GST_ROUND_UP_2 (height) / 2);
      break;
    case GST_VIDEO_FORMAT_YUV9:
      info->stride[0] = GST_ROUND_UP_4 (width);
      info->stride[1] = GST_ROUND_UP_4 (GST_ROUND_UP_4 (width) / 4);
      info->stride[2] = info->stride[1];
      info->offset[0] = 0;
      info->offset[1] = info->stride[0] * height;
      info->offset[2] = info->offset[1] +
          info->stride[1] * (GST_ROUND_UP_4 (height) / 4);
      break;
    case GST_VIDEO_FORMAT_YVU9:
      info->stride[0] = GST_ROUND_UP_4 (width);
      info->stride[1] = GST_ROUND_UP_4 (GST_ROUND_UP_4 (width) / 4);
      info->stride[2] = info->stride[1];
      info->offset[0] = 0;
      info->offset[2] = info->stride[0] * height;
      info->offset[1] = info->offset[2] +
          info->stride[1] * (GST_ROUND_UP_4 (height) / 4);
      break;
    case GST_VIDEO_FORMAT_I420_10LE:
    case GST_VIDEO_FORMAT_I420_10BE:
      info->stride[0] = GST_ROUND_UP_4 (width * 2);
      info->stride[1] = GST_ROUND_UP_4 (width);
      info->stride[2] = info->stride[1];
      info->offset[0] = 0;
      info->offset[1] = info->stride[0] * GST_ROUND_UP_2 (height);
      info->offset[2] = info->offset[1] +
          info->stride[1] * (GST_ROUND_UP_2 (height) / 2);
      info->size = info->offset[2] +
          info->stride[2] * (GST_ROUND_UP_2 (height) / 2);
      break;
    case GST_VIDEO_FORMAT_I422_10LE:
    case GST_VIDEO_FORMAT_I422_10BE:
      info->stride[0] = GST_ROUND_UP_4 (width * 2);
      info->stride[1] = GST_ROUND_UP_4 (width);
      info->stride[2] = info->stride[1];
      info->offset[0] = 0;
      info->offset[1] = info->stride[0] * GST_ROUND_UP_2 (height);
      info->offset[2] = info->offset[1] +
          info->stride[1] * GST_ROUND_UP_2 (height);
      info->size = info->offset[2] + info->stride[2] * GST_ROUND_UP_2 (height);
      break;
    case GST_VIDEO_FORMAT_Y444_10LE:
    case GST_VIDEO_FORMAT_Y444_10BE:
      info->stride[0] = GST_ROUND_UP_4 (width * 2);
      info->stride[1] = info->stride[0];
      info->stride[2] = info->stride[0];
      info->offset[0] = 0;
      info->offset[1] = info->stride[0] * height;
      info->offset[2] = info->offset[1] * 2;
      info->size = info->stride[0] * height * 3;
      break;
    case GST_VIDEO_FORMAT_UNKNOWN:
    default:
      GST_ERROR ("invalid format");
      g_warning ("invalid format");
      break;
  }
  return 0;
}

//.........这里部分代码省略.........
  BaseTimeType *base_time;
  GstClockTime offset;

  g_signal_emit_by_name (appsink, "pull-sample", &sample);
  if (sample == NULL)
    return GST_FLOW_OK;

  buffer = gst_sample_get_buffer (sample);
  if (buffer == NULL) {
    ret = GST_FLOW_OK;
    goto end;
  }

  segment = gst_sample_get_segment (sample);

  g_object_get (G_OBJECT (self), "state", &state, NULL);
  if (state != KMS_URI_ENDPOINT_STATE_START) {
    GST_WARNING ("Dropping buffer received in invalid state %" GST_PTR_FORMAT,
        buffer);
    // TODO: Add a flag to discard buffers until keyframe
    ret = GST_FLOW_OK;
    goto end;
  }

  gst_buffer_ref (buffer);
  buffer = gst_buffer_make_writable (buffer);

  if (GST_BUFFER_PTS_IS_VALID (buffer))
    buffer->pts =
        gst_segment_to_running_time (segment, GST_FORMAT_TIME, buffer->pts);
  if (GST_BUFFER_DTS_IS_VALID (buffer))
    buffer->dts =
        gst_segment_to_running_time (segment, GST_FORMAT_TIME, buffer->dts);

  BASE_TIME_LOCK (self);

  base_time = g_object_get_data (G_OBJECT (self), BASE_TIME_DATA);

  if (base_time == NULL) {
    base_time = g_slice_new0 (BaseTimeType);
    base_time->pts = buffer->pts;
    base_time->dts = buffer->dts;
    GST_DEBUG_OBJECT (appsrc, "Setting pts base time to: %" G_GUINT64_FORMAT,
        base_time->pts);
    g_object_set_data_full (G_OBJECT (self), BASE_TIME_DATA, base_time,
        release_base_time_type);
  }

  if (!GST_CLOCK_TIME_IS_VALID (base_time->pts)
      && GST_BUFFER_PTS_IS_VALID (buffer)) {
    base_time->pts = buffer->pts;
    GST_DEBUG_OBJECT (appsrc, "Setting pts base time to: %" G_GUINT64_FORMAT,
        base_time->pts);
    base_time->dts = buffer->dts;
  }

  if (GST_CLOCK_TIME_IS_VALID (base_time->pts)) {
    if (GST_BUFFER_PTS_IS_VALID (buffer)) {
      offset = base_time->pts + self->priv->paused_time;
      if (buffer->pts > offset) {
        buffer->pts -= offset;
      } else {
        buffer->pts = 0;
      }
    }
  }

  if (GST_CLOCK_TIME_IS_VALID (base_time->dts)) {
    if (GST_BUFFER_DTS_IS_VALID (buffer)) {
      offset = base_time->dts + self->priv->paused_time;
      if (buffer->dts > offset) {
        buffer->dts -= offset;
      } else {
        buffer->dts = 0;
      }
    }
  }

  BASE_TIME_UNLOCK (GST_OBJECT_PARENT (appsink));

  GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_LIVE);

  if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_HEADER))
    GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DISCONT);

  ret = gst_app_src_push_buffer (appsrc, buffer);

  if (ret != GST_FLOW_OK) {
    /* something wrong */
    GST_ERROR ("Could not send buffer to appsrc %s. Cause: %s",
        GST_ELEMENT_NAME (appsrc), gst_flow_get_name (ret));
  }

end:
  if (sample != NULL) {
    gst_sample_unref (sample);
  }

  return ret;
}

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;

  /* 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;
  }
}

static gboolean gst_gcs_set_caps(GstBaseTransform * btrans, GstCaps * incaps, GstCaps * outcaps) 
{
  GstGcs *gcs = GST_GCS (btrans);
  gint in_width, in_height;
  gint out_width, out_height;
  
  GST_GCS_LOCK (gcs);
  
  gst_video_format_parse_caps(incaps, &gcs->in_format, &in_width, &in_height);
  gst_video_format_parse_caps(outcaps, &gcs->out_format, &out_width, &out_height);
  if (!(gcs->in_format == gcs->out_format) || 
      !(in_width == out_width && in_height == out_height)) {
    GST_WARNING("Failed to parse caps %" GST_PTR_FORMAT " -> %" GST_PTR_FORMAT, incaps, outcaps);
    GST_GCS_UNLOCK (gcs);
    return FALSE;
  }
  
  gcs->width  = in_width;
  gcs->height = in_height;
  
  GST_INFO("Initialising Gcs...");
  gst_pad_set_event_function(GST_BASE_TRANSFORM_SINK_PAD(gcs),  gst_gcs_sink_event);

  const CvSize size = cvSize(gcs->width, gcs->height);
  GST_WARNING (" width %d, height %d", gcs->width, gcs->height);

  //////////////////////////////////////////////////////////////////////////////
  // allocate image structs in all spaces///////////////////////////////////////
  gcs->pImageRGBA    = cvCreateImageHeader(size, IPL_DEPTH_8U, 4);

  gcs->pImgRGB       = cvCreateImage(size, IPL_DEPTH_8U, 3);
  gcs->pImgScratch   = cvCreateImage(size, IPL_DEPTH_8U, 3);

  gcs->pImgGRAY      = cvCreateImage(size, IPL_DEPTH_8U, 1);
  gcs->pImgGRAY_copy = cvCreateImage(size, IPL_DEPTH_8U, 1);
  gcs->pImgGRAY_diff = cvCreateImage(size, IPL_DEPTH_8U, 1);
  gcs->pImgGRAY_1    = cvCreateImage(size, IPL_DEPTH_8U, 1);
  gcs->pImgGRAY_1copy= cvCreateImage(size, IPL_DEPTH_8U, 1);
  cvZero( gcs->pImgGRAY_1 );
  cvZero( gcs->pImgGRAY_1copy );

  gcs->pImgChA       = cvCreateImageHeader(size, IPL_DEPTH_8U, 1);
  gcs->pImgCh1       = cvCreateImage(size, IPL_DEPTH_8U, 1);
  gcs->pImgCh2       = cvCreateImage(size, IPL_DEPTH_8U, 1);
  gcs->pImgCh3       = cvCreateImage(size, IPL_DEPTH_8U, 1);
  gcs->pImgChX       = cvCreateImage(size, IPL_DEPTH_8U, 1);

  gcs->pImg_skin     = cvCreateImage(size, IPL_DEPTH_8U, 1);

  gcs->grabcut_mask   = cvCreateMat( size.height, size.width, CV_8UC1);
  cvZero(gcs->grabcut_mask);
  initialise_grabcut( &(gcs->GC), gcs->pImgRGB, gcs->grabcut_mask );
  gcs->bbox_prev      = cvRect( 60,70, 210, 170 );

  //////////////////////////////////////////////////////////////////////////////
#ifdef KMEANS
  // k-means allocation ////////////////////////////////////////////////////////
  gcs->pImgRGB_kmeans  = cvCreateImage(size, IPL_DEPTH_8U, 3);
  gcs->num_samples     = size.height * size.width;
  gcs->kmeans_points   = cvCreateMat( gcs->num_samples, 5, CV_32FC1);
  gcs->kmeans_clusters = cvCreateMat( gcs->num_samples, 1, CV_32SC1);
#endif //KMEANS

  //////////////////////////////////////////////////////////////////////////////
  // Init ghost file ///////////////////////////////////////////////////////////
  curlMemoryStructGCS  chunk;
  //gchar url[]="file:///home/mcasassa/imco2/mods/gstreamer/cyclops/shaders/mask8.png";
  //gchar url[]="file:///apps/devnfs/mcasassa/mask_320x240.png";
  char curlErrBuf[255];
  
  if( gcs->ghostfilename){
    if(FALSE == curl_download(gcs->ghostfilename, "", &chunk, curlErrBuf)) {
      GST_ERROR("download failed, err: %s", curlErrBuf);
    }
    
    char errBuf[255];
    if( FALSE == read_png(&chunk, &(gcs->raw_image), &(gcs->info), errBuf)){
      GST_ERROR("png load failed, err: %s", errBuf);
    }

    const CvSize sizegh = cvSize(gcs->info.width, gcs->info.height);
    gcs->cvGhost = cvCreateImageHeader(sizegh, IPL_DEPTH_8U, gcs->info.channels);
    gcs->cvGhost->imageData = (char*)gcs->raw_image;

    gcs->cvGhostBw = cvCreateImage(sizegh, IPL_DEPTH_8U, 1);
    if( gcs->info.channels > 1){
      cvCvtColor( gcs->cvGhost, gcs->cvGhostBw, CV_RGB2GRAY );
    }
    else{
      cvCopy(gcs->cvGhost, gcs->cvGhostBw, NULL);
    }

    gcs->cvGhostBwResized = cvCreateImage(size, IPL_DEPTH_8U, 1);
    cvResize( gcs->cvGhostBw, gcs->cvGhostBwResized, CV_INTER_LINEAR);

    gcs->cvGhostBwAffined = cvCreateImage(size, IPL_DEPTH_8U, 1);
  }

  GST_INFO(" Collected caps, image in size (%dx%d), ghost size (%dx%d) %dch",gcs->width, gcs->height,
            gcs->info.width, gcs->info.height, gcs->info.channels );
//.........这里部分代码省略.........

//.........这里部分代码省略.........
          /* HEADERS */
          GST_DEBUG ("Headers");
          /* Store the incoming timestamp */
          rtpqdm2depay->ptimestamp = rtpqdm2depay->timestamp;
          rtpqdm2depay->timestamp = GST_BUFFER_TIMESTAMP (buf);
          /* flush the internal data if needed */
          flush_data (rtpqdm2depay);
          if (G_UNLIKELY (!rtpqdm2depay->configured)) {
            guint8 *ourdata;
            GstBuffer *codecdata;
            GstCaps *caps;

            /* First bytes are unknown */
            GST_MEMDUMP ("Header", payload + pos, 32);
            ourdata = payload + pos + 10;
            pos += 10;
            rtpqdm2depay->channs = GST_READ_UINT32_BE (payload + pos + 4);
            rtpqdm2depay->samplerate = GST_READ_UINT32_BE (payload + pos + 8);
            rtpqdm2depay->bitrate = GST_READ_UINT32_BE (payload + pos + 12);
            rtpqdm2depay->blocksize = GST_READ_UINT32_BE (payload + pos + 16);
            rtpqdm2depay->framesize = GST_READ_UINT32_BE (payload + pos + 20);
            rtpqdm2depay->packetsize = GST_READ_UINT32_BE (payload + pos + 24);
            /* 16 bit empty block (0x02 0x00) */
            pos += 30;
            GST_DEBUG
                ("channs:%d, samplerate:%d, bitrate:%d, blocksize:%d, framesize:%d, packetsize:%d",
                rtpqdm2depay->channs, rtpqdm2depay->samplerate,
                rtpqdm2depay->bitrate, rtpqdm2depay->blocksize,
                rtpqdm2depay->framesize, rtpqdm2depay->packetsize);

            /* Caps */
            codecdata = gst_buffer_new_and_alloc (48);
            memcpy (GST_BUFFER_DATA (codecdata), headheader, 20);
            memcpy (GST_BUFFER_DATA (codecdata) + 20, ourdata, 28);

            caps = gst_caps_new_simple ("audio/x-qdm2",
                "samplesize", G_TYPE_INT, 16,
                "rate", G_TYPE_INT, rtpqdm2depay->samplerate,
                "channels", G_TYPE_INT, rtpqdm2depay->channs,
                "codec_data", GST_TYPE_BUFFER, codecdata, NULL);
            gst_pad_set_caps (GST_BASE_RTP_DEPAYLOAD_SRCPAD (depayload), caps);
            gst_caps_unref (caps);
            rtpqdm2depay->configured = TRUE;
          } else {
            GST_DEBUG ("Already configured, skipping headers");
            pos += 40;
          }
          break;
        default:{
          /* Shuffled packet contents */
          guint packetid = payload[pos++];
          guint packettype = payload[pos++];
          guint packlen = payload[pos++];
          guint hsize = 2;

          GST_DEBUG ("Packet id:%d, type:0x%x, len:%d",
              packetid, packettype, packlen);

          /* Packets bigger than 0xff bytes have a type with the high bit set */
          if (G_UNLIKELY (packettype & 0x80)) {
            packettype &= 0x7f;
            packlen <<= 8;
            packlen |= payload[pos++];
            hsize = 3;
            GST_DEBUG ("Packet id:%d, type:0x%x, len:%d",
                packetid, packettype, packlen);
          }

          if (packettype > 0x7f) {
            GST_ERROR ("HOUSTON WE HAVE A PROBLEM !!!!");
          }
          add_packet (rtpqdm2depay, packetid, packlen + hsize,
              payload + pos - hsize);
          pos += packlen;
        }
      }
    }

    GST_DEBUG ("final pos %d", pos);

    avail = gst_adapter_available (rtpqdm2depay->adapter);
    if (G_UNLIKELY (avail)) {
      GST_DEBUG ("Pushing out %d bytes of collected data", avail);
      outbuf = gst_adapter_take_buffer (rtpqdm2depay->adapter, avail);
      GST_BUFFER_TIMESTAMP (outbuf) = rtpqdm2depay->ptimestamp;
      GST_DEBUG ("Outgoing buffer timestamp %" GST_TIME_FORMAT,
          GST_TIME_ARGS (rtpqdm2depay->ptimestamp));
      return outbuf;
    }
  }
  return NULL;

  /* ERRORS */
bad_packet:
  {
    GST_ELEMENT_WARNING (rtpqdm2depay, STREAM, DECODE,
        (NULL), ("Packet was too short"));
    return NULL;
  }
}

static void
on_error_cb (GMarkupParseContext * context, GError * error, gpointer user_data)
{
  GST_ERROR ("Error parsing file: %s", error->message);
}

//.........这里部分代码省略.........

  if (!gst_egl_image_memory_is_mappable ())
    flags |= GST_MEMORY_FLAG_NOT_MAPPABLE;
  /* See https://bugzilla.gnome.org/show_bug.cgi?id=695203 */
  flags |= GST_MEMORY_FLAG_NO_SHARE;

  gst_video_info_set_format (&info, format, width, height);

  GST_DEBUG ("Allocating EGL Image format %s width %d height %d",
      gst_video_format_to_string (format), width, height);
  switch (format) {
    case GST_VIDEO_FORMAT_RGBA:{
      gsize size;
      EGLImageKHR image;

      mem[0] =
          gst_egl_image_allocator_alloc (allocator, ctx->gst_display,
          GST_VIDEO_GL_TEXTURE_TYPE_RGBA, GST_VIDEO_INFO_WIDTH (&info),
          GST_VIDEO_INFO_HEIGHT (&info), &size);

      if (mem[0]) {
        stride[0] = size / GST_VIDEO_INFO_HEIGHT (&info);
        n_mem = 1;
        GST_MINI_OBJECT_FLAG_SET (mem[0], GST_MEMORY_FLAG_NO_SHARE);
      } else {
        data = g_slice_new0 (GstEGLGLESImageData);

        stride[0] = GST_ROUND_UP_4 (GST_VIDEO_INFO_WIDTH (&info) * 4);
        size = stride[0] * GST_VIDEO_INFO_HEIGHT (&info);

        glGenTextures (1, &data->texture);
        if (got_gl_error ("glGenTextures"))
          goto mem_error;

        glBindTexture (GL_TEXTURE_2D, data->texture);
        if (got_gl_error ("glBindTexture"))
          goto mem_error;

        /* Set 2D resizing params */
        glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

        /* If these are not set the texture image unit will return
         * * (R, G, B, A) = black on glTexImage2D for non-POT width/height
         * * frames. For a deeper explanation take a look at the OpenGL ES
         * * documentation for glTexParameter */
        glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        if (got_gl_error ("glTexParameteri"))
          goto mem_error;

        glTexImage2D (GL_TEXTURE_2D, 0, GL_RGBA,
            GST_VIDEO_INFO_WIDTH (&info),
            GST_VIDEO_INFO_HEIGHT (&info), 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
        if (got_gl_error ("glTexImage2D"))
          goto mem_error;

        image =
            eglCreateImageKHR (gst_egl_display_get (ctx->gst_display),
            ctx->context, EGL_GL_TEXTURE_2D_KHR,
            (EGLClientBuffer) (guintptr) data->texture, NULL);
        if (got_egl_error ("eglCreateImageKHR"))
          goto mem_error;

        mem[0] =
            gst_egl_image_allocator_wrap (allocator, ctx->gst_display,
            image, GST_VIDEO_GL_TEXTURE_TYPE_RGBA, flags, size, data, NULL);

        n_mem = 1;
      }
    }
      break;
    default:
      goto mem_error;
      break;
  }

  buffer = gst_buffer_new ();
  gst_buffer_add_video_meta_full (buffer, 0, format, width, height,
      GST_VIDEO_INFO_N_PLANES (&info), offset, stride);

  /* n_mem could be reused for planar colorspaces, for now its == 1 for RGBA */
  for (i = 0; i < n_mem; i++)
    gst_buffer_append_memory (buffer, mem[i]);

  return buffer;
mem_error:
  {
    GST_ERROR ("Failed to create EGLImage");

    if (data)
      gst_egl_gles_image_data_free (data);

    if (mem[0])
      gst_memory_unref (mem[0]);

    return NULL;
  }

}