/* For the clock skew we use a windowed low point averaging algorithm as can be
 * found in Fober, Orlarey and Letz, 2005, "Real Time Clock Skew Estimation
 * over Network Delays":
 * http://www.grame.fr/Ressources/pub/TR-050601.pdf
 * http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.102.1546
 *
 * The idea is that the jitter is composed of:
 *
 *  J = N + n
 *
 *   N   : a constant network delay.
 *   n   : random added noise. The noise is concentrated around 0
 *
 * In the receiver we can track the elapsed time at the sender with:
 *
 *  send_diff(i) = (Tsi - Ts0);
 *
 *   Tsi : The time at the sender at packet i
 *   Ts0 : The time at the sender at the first packet
 *
 * This is the difference between the RTP timestamp in the first received packet
 * and the current packet.
 *
 * At the receiver we have to deal with the jitter introduced by the network.
 *
 *  recv_diff(i) = (Tri - Tr0)
 *
 *   Tri : The time at the receiver at packet i
 *   Tr0 : The time at the receiver at the first packet
 *
 * Both of these values contain a jitter Ji, a jitter for packet i, so we can
 * write:
 *
 *  recv_diff(i) = (Cri + D + ni) - (Cr0 + D + n0))
 *
 *    Cri    : The time of the clock at the receiver for packet i
 *    D + ni : The jitter when receiving packet i
 *
 * We see that the network delay is irrelevant here as we can elliminate D:
 *
 *  recv_diff(i) = (Cri + ni) - (Cr0 + n0))
 *
 * The drift is now expressed as:
 *
 *  Drift(i) = recv_diff(i) - send_diff(i);
 *
 * We now keep the W latest values of Drift and find the minimum (this is the
 * one with the lowest network jitter and thus the one which is least affected
 * by it). We average this lowest value to smooth out the resulting network skew.
 *
 * Both the window and the weighting used for averaging influence the accuracy
 * of the drift estimation. Finding the correct parameters turns out to be a
 * compromise between accuracy and inertia.
 *
 * We use a 2 second window or up to 512 data points, which is statistically big
 * enough to catch spikes (FIXME, detect spikes).
 * We also use a rather large weighting factor (125) to smoothly adapt. During
 * startup, when filling the window, we use a parabolic weighting factor, the
 * more the window is filled, the faster we move to the detected possible skew.
 *
 * Returns: @time adjusted with the clock skew.
 */
static GstClockTime
calculate_skew (RTPJitterBuffer * jbuf, guint32 rtptime, GstClockTime time,
    guint32 clock_rate)
{
  guint64 ext_rtptime;
  guint64 send_diff, recv_diff;
  gint64 delta;
  gint64 old;
  gint pos, i;
  GstClockTime gstrtptime, out_time;
  guint64 slope;

  ext_rtptime = gst_rtp_buffer_ext_timestamp (&jbuf->ext_rtptime, rtptime);

  gstrtptime = gst_util_uint64_scale_int (ext_rtptime, GST_SECOND, clock_rate);

  /* keep track of the last extended rtptime */
  jbuf->last_rtptime = ext_rtptime;

  if (jbuf->clock_rate != clock_rate) {
    if (jbuf->clock_rate == -1) {
      GST_DEBUG ("Clock rate changed from %" G_GUINT32_FORMAT " to %"
          G_GUINT32_FORMAT, jbuf->clock_rate, clock_rate);
    } else {
      GST_WARNING ("Clock rate changed from %" G_GUINT32_FORMAT " to %"
          G_GUINT32_FORMAT, jbuf->clock_rate, clock_rate);
    }
    jbuf->base_time = -1;
    jbuf->base_rtptime = -1;
    jbuf->clock_rate = clock_rate;
    jbuf->prev_out_time = -1;
    jbuf->prev_send_diff = -1;
  }

  /* first time, lock on to time and gstrtptime */
  if (G_UNLIKELY (jbuf->base_time == -1)) {
    jbuf->base_time = time;
    jbuf->prev_out_time = -1;
//.........这里部分代码省略.........

GstFlowReturn
gst_base_video_decoder_finish_frame (GstBaseVideoDecoder * base_video_decoder,
    GstVideoFrame * frame)
{
  GstBaseVideoDecoderClass *base_video_decoder_class;
  GstBuffer *src_buffer;

  GST_DEBUG ("finish frame");

  base_video_decoder_class =
      GST_BASE_VIDEO_DECODER_GET_CLASS (base_video_decoder);

  GST_DEBUG ("finish frame sync=%d pts=%" GST_TIME_FORMAT, frame->is_sync_point,
      GST_TIME_ARGS (frame->presentation_timestamp));

  if (GST_CLOCK_TIME_IS_VALID (frame->presentation_timestamp)) {
    if (frame->presentation_timestamp != base_video_decoder->timestamp_offset) {
      GST_DEBUG ("sync timestamp %" GST_TIME_FORMAT " diff %" GST_TIME_FORMAT,
          GST_TIME_ARGS (frame->presentation_timestamp),
          GST_TIME_ARGS (frame->presentation_timestamp -
              base_video_decoder->segment.start));
      base_video_decoder->timestamp_offset = frame->presentation_timestamp;
      base_video_decoder->field_index = 0;
    } else {
      /* This case is for one initial timestamp and no others, e.g.,
       * filesrc ! decoder ! xvimagesink */
      GST_WARNING ("sync timestamp didn't change, ignoring");
      frame->presentation_timestamp = GST_CLOCK_TIME_NONE;
    }
  } else {
    if (frame->is_sync_point) {
      GST_WARNING ("sync point doesn't have timestamp");
      if (!GST_CLOCK_TIME_IS_VALID (base_video_decoder->timestamp_offset)) {
        GST_WARNING
            ("No base timestamp.  Assuming frames start at segment start");
        base_video_decoder->timestamp_offset =
            base_video_decoder->segment.start;
        base_video_decoder->field_index = 0;
      }
    }
  }
  frame->field_index = base_video_decoder->field_index;
  base_video_decoder->field_index += frame->n_fields;

  if (frame->presentation_timestamp == GST_CLOCK_TIME_NONE) {
    frame->presentation_timestamp =
        gst_base_video_decoder_get_field_timestamp (base_video_decoder,
        frame->field_index);
    frame->presentation_duration = GST_CLOCK_TIME_NONE;
    frame->decode_timestamp =
        gst_base_video_decoder_get_timestamp (base_video_decoder,
        frame->decode_frame_number);
  }
  if (frame->presentation_duration == GST_CLOCK_TIME_NONE) {
    frame->presentation_duration =
        gst_base_video_decoder_get_field_duration (base_video_decoder,
        frame->n_fields);
  }

  if (GST_CLOCK_TIME_IS_VALID (base_video_decoder->last_timestamp)) {
    if (frame->presentation_timestamp < base_video_decoder->last_timestamp) {
      GST_WARNING ("decreasing timestamp (%" GST_TIME_FORMAT " < %"
          GST_TIME_FORMAT ")", GST_TIME_ARGS (frame->presentation_timestamp),
          GST_TIME_ARGS (base_video_decoder->last_timestamp));
    }
  }
  base_video_decoder->last_timestamp = frame->presentation_timestamp;

  GST_BUFFER_FLAG_UNSET (frame->src_buffer, GST_BUFFER_FLAG_DELTA_UNIT);
  if (base_video_decoder->state.interlaced) {
#ifndef GST_VIDEO_BUFFER_TFF
#define GST_VIDEO_BUFFER_TFF (GST_MINI_OBJECT_FLAG_LAST << 5)
#endif
#ifndef GST_VIDEO_BUFFER_RFF
#define GST_VIDEO_BUFFER_RFF (GST_MINI_OBJECT_FLAG_LAST << 6)
#endif
#ifndef GST_VIDEO_BUFFER_ONEFIELD
#define GST_VIDEO_BUFFER_ONEFIELD (GST_MINI_OBJECT_FLAG_LAST << 7)
#endif
    int tff = base_video_decoder->state.top_field_first;

    if (frame->field_index & 1) {
      tff ^= 1;
    }
    if (tff) {
      GST_BUFFER_FLAG_SET (frame->src_buffer, GST_VIDEO_BUFFER_TFF);
    } else {
      GST_BUFFER_FLAG_UNSET (frame->src_buffer, GST_VIDEO_BUFFER_TFF);
    }
    GST_BUFFER_FLAG_UNSET (frame->src_buffer, GST_VIDEO_BUFFER_RFF);
    GST_BUFFER_FLAG_UNSET (frame->src_buffer, GST_VIDEO_BUFFER_ONEFIELD);
    if (frame->n_fields == 3) {
      GST_BUFFER_FLAG_SET (frame->src_buffer, GST_VIDEO_BUFFER_RFF);
    } else if (frame->n_fields == 1) {
      GST_BUFFER_FLAG_UNSET (frame->src_buffer, GST_VIDEO_BUFFER_ONEFIELD);
    }
  }
  if (base_video_decoder->discont) {
    GST_BUFFER_FLAG_UNSET (frame->src_buffer, GST_BUFFER_FLAG_DISCONT);
    base_video_decoder->discont = FALSE;
//.........这里部分代码省略.........

static gboolean
setup_recoder_pipeline (GstSmartEncoder * smart_encoder)
{
  GstPad *tmppad;
  GstCaps *caps;

  /* Fast path */
  if (G_UNLIKELY (smart_encoder->encoder))
    return TRUE;

  GST_DEBUG ("Creating internal decoder and encoder");

  /* Create decoder/encoder */
  caps = gst_pad_get_current_caps (smart_encoder->sinkpad);
  smart_encoder->decoder = get_decoder (caps);
  if (G_UNLIKELY (smart_encoder->decoder == NULL))
    goto no_decoder;
  gst_caps_unref (caps);
  gst_element_set_bus (smart_encoder->decoder, GST_ELEMENT_BUS (smart_encoder));

  caps = gst_pad_get_current_caps (smart_encoder->sinkpad);
  smart_encoder->encoder = get_encoder (caps);
  if (G_UNLIKELY (smart_encoder->encoder == NULL))
    goto no_encoder;
  gst_caps_unref (caps);
  gst_element_set_bus (smart_encoder->encoder, GST_ELEMENT_BUS (smart_encoder));

  GST_DEBUG ("Creating internal pads");

  /* Create internal pads */

  /* Source pad which we'll use to feed data to decoders */
  smart_encoder->internal_srcpad = gst_pad_new ("internal_src", GST_PAD_SRC);
  g_object_set_qdata ((GObject *) smart_encoder->internal_srcpad,
      INTERNAL_ELEMENT, smart_encoder);
  gst_pad_set_active (smart_encoder->internal_srcpad, TRUE);

  /* Sink pad which will get the buffers from the encoder.
   * Note: We don't need an event function since we'll be discarding all
   * of them. */
  smart_encoder->internal_sinkpad = gst_pad_new ("internal_sink", GST_PAD_SINK);
  g_object_set_qdata ((GObject *) smart_encoder->internal_sinkpad,
      INTERNAL_ELEMENT, smart_encoder);
  gst_pad_set_chain_function (smart_encoder->internal_sinkpad, internal_chain);
  gst_pad_set_active (smart_encoder->internal_sinkpad, TRUE);

  GST_DEBUG ("Linking pads to elements");

  /* Link everything */
  tmppad = gst_element_get_static_pad (smart_encoder->encoder, "src");
  if (GST_PAD_LINK_FAILED (gst_pad_link (tmppad,
              smart_encoder->internal_sinkpad)))
    goto sinkpad_link_fail;
  gst_object_unref (tmppad);

  if (!gst_element_link (smart_encoder->decoder, smart_encoder->encoder))
    goto encoder_decoder_link_fail;

  tmppad = gst_element_get_static_pad (smart_encoder->decoder, "sink");
  if (GST_PAD_LINK_FAILED (gst_pad_link (smart_encoder->internal_srcpad,
              tmppad)))
    goto srcpad_link_fail;
  gst_object_unref (tmppad);

  GST_DEBUG ("Done creating internal elements/pads");

  return TRUE;

no_decoder:
  {
    GST_WARNING ("Couldn't find a decoder for %" GST_PTR_FORMAT, caps);
    gst_caps_unref (caps);
    return FALSE;
  }

no_encoder:
  {
    GST_WARNING ("Couldn't find an encoder for %" GST_PTR_FORMAT, caps);
    gst_caps_unref (caps);
    return FALSE;
  }

srcpad_link_fail:
  {
    gst_object_unref (tmppad);
    GST_WARNING ("Couldn't link internal srcpad to decoder");
    return FALSE;
  }

sinkpad_link_fail:
  {
    gst_object_unref (tmppad);
    GST_WARNING ("Couldn't link encoder to internal sinkpad");
    return FALSE;
  }

encoder_decoder_link_fail:
  {
    GST_WARNING ("Couldn't link decoder to encoder");
    return FALSE;
//.........这里部分代码省略.........

//
// Expected synchronisation from caller. This method is not thread-safe!
//
bool DiscretixSession::dxdrmProcessKey(Uint8Array* key, RefPtr<Uint8Array>& nextMessage, unsigned short& errorCode, unsigned long& systemCode)
{
    GST_MEMDUMP("response received :", key->data(), key->byteLength());

    bool isAckRequired;
    HDxResponseResult responseResult = nullptr;
    EDxDrmStatus status = DX_ERROR_CONTENT_NOT_RECOGNIZED;

    errorCode = 0;
    if (m_state == PHASE_INITIAL) {
        // Server replied to our license request
        status = DxDrmStream_ProcessLicenseResponse(m_DxDrmStream, key->data(), key->byteLength(), &responseResult, &isAckRequired);

        if (status == DX_SUCCESS) {
            // Create a deep copy of the key.
            m_key = key->buffer();
            m_state = (isAckRequired ? PHASE_ACKNOWLEDGE : PHASE_PROVISIONED);
            GST_DEBUG("Acknowledgement required: %s", isAckRequired ? "yes" : "no");
        }

    } else if (m_state == PHASE_ACKNOWLEDGE) {

        // Server replied to our license response acknowledge
        status = DxDrmClient_ProcessServerResponse(key->data(), key->byteLength(), DX_RESPONSE_LICENSE_ACK, &responseResult, &isAckRequired);

        if (status == DX_SUCCESS) {
            // Create a deep copy of the key.
            m_key = key->buffer();
            m_state = (isAckRequired ? PHASE_ACKNOWLEDGE : PHASE_PROVISIONED);

            if (m_state == PHASE_ACKNOWLEDGE)
                GST_WARNING("Acknowledging an Ack. Strange situation.");
        }
    } else
        GST_WARNING("Unexpected call. We are already provisioned");

    if (status != DX_SUCCESS) {
        GST_ERROR("failed processing license response (status: %d)", status);
        errorCode = MediaKeyError::MEDIA_KEYERR_CLIENT;
    } else if (m_state == PHASE_PROVISIONED) {
        status = DxDrmStream_SetIntent(m_DxDrmStream, DX_INTENT_AUTO_PLAY, DX_AUTO_NO_UI);
        if (status != DX_SUCCESS)
            GST_ERROR("opening stream failed because there are no rights (license) to play the content (status: %d)", status);
        else {
            GST_INFO("playback rights found");

            /* starting consumption of the file - notifying the drm that the file is being used */
            status = DxDrmFile_HandleConsumptionEvent(m_DxDrmStream, DX_EVENT_START);
            if (status != DX_SUCCESS)
                GST_ERROR("Content consumption failed");
            else {
                GST_INFO("Stream was opened and is ready for playback");
                m_ready = true;
            }
        }

    } else if (m_state == PHASE_ACKNOWLEDGE) {
        uint32_t challengeLength = MAX_CHALLENGE_LEN;
        unsigned char* challenge = static_cast<unsigned char*>(g_malloc0(challengeLength));

        status = DxDrmClient_GetLicenseAcq_GenerateAck(&responseResult, challenge, &challengeLength);
        if (status != DX_SUCCESS)
            GST_ERROR("failed generating license ack challenge (status: %d, response result %p)", status, responseResult);

        GST_MEMDUMP("generated license ack request :", challenge, challengeLength);

        nextMessage = Uint8Array::create(challenge, challengeLength);
        g_free(challenge);
    }

    systemCode = status;

    return (status == DX_SUCCESS);
}

static gboolean
gst_base_video_decoder_sink_event (GstPad * pad, GstEvent * event)
{
  GstBaseVideoDecoder *base_video_decoder;
  GstBaseVideoDecoderClass *base_video_decoder_class;
  gboolean ret = FALSE;

  base_video_decoder = GST_BASE_VIDEO_DECODER (gst_pad_get_parent (pad));
  base_video_decoder_class =
      GST_BASE_VIDEO_DECODER_GET_CLASS (base_video_decoder);

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_EOS:
    {
      if (!base_video_decoder->packetized) {
        GstFlowReturn flow_ret;

        do {
          flow_ret =
              base_video_decoder_class->parse_data (base_video_decoder, TRUE);
        } while (flow_ret == GST_FLOW_OK);
      }

      if (base_video_decoder_class->finish) {
        base_video_decoder_class->finish (base_video_decoder);
      }

      ret =
          gst_pad_push_event (GST_BASE_VIDEO_CODEC_SRC_PAD (base_video_decoder),
          event);
    }
      break;
    case GST_EVENT_NEWSEGMENT:
    {
      gboolean update;
      double rate;
      double applied_rate;
      GstFormat format;
      gint64 start;
      gint64 stop;
      gint64 position;
      GstSegment *segment = &base_video_decoder->segment;

      gst_event_parse_new_segment_full (event, &update, &rate,
          &applied_rate, &format, &start, &stop, &position);

      if (format != GST_FORMAT_TIME)
        goto newseg_wrong_format;

      if (!update) {
        gst_base_video_decoder_reset (base_video_decoder);
      }

      base_video_decoder->timestamp_offset = start;

      gst_segment_set_newsegment_full (segment,
          update, rate, applied_rate, format, start, stop, position);
      base_video_decoder->have_segment = TRUE;

      GST_WARNING ("new segment: format %d rate %g start %" GST_TIME_FORMAT
          " stop %" GST_TIME_FORMAT
          " position %" GST_TIME_FORMAT
          " update %d",
          format, rate,
          GST_TIME_ARGS (segment->start),
          GST_TIME_ARGS (segment->stop), GST_TIME_ARGS (segment->time), update);

      ret =
          gst_pad_push_event (GST_BASE_VIDEO_CODEC_SRC_PAD (base_video_decoder),
          event);
    }
      break;
    case GST_EVENT_FLUSH_STOP:{
      GST_OBJECT_LOCK (base_video_decoder);
      base_video_decoder->earliest_time = GST_CLOCK_TIME_NONE;
      base_video_decoder->proportion = 0.5;
      GST_OBJECT_UNLOCK (base_video_decoder);
    }
    default:
      /* FIXME this changes the order of events */
      ret =
          gst_pad_push_event (GST_BASE_VIDEO_CODEC_SRC_PAD (base_video_decoder),
          event);
      break;
  }

done:
  gst_object_unref (base_video_decoder);
  return ret;

newseg_wrong_format:
  {
    GST_DEBUG_OBJECT (base_video_decoder, "received non TIME newsegment");
    gst_event_unref (event);
    goto done;
  }
}

/* returns static descriptions and dynamic ones (such as video/x-raw-yuv),
 * or NULL if caps aren't known at all */
static gchar *
format_info_get_desc (const FormatInfo * info, const GstCaps * caps)
{
  const GstStructure *s;

  g_assert (info != NULL);

  if (info->desc != NULL)
    return g_strdup (_(info->desc));

  s = gst_caps_get_structure (caps, 0);

  if (strcmp (info->type, "video/x-raw-yuv") == 0) {
    const gchar *ret = NULL;
    guint32 fourcc = 0;

    gst_structure_get_fourcc (s, "format", &fourcc);
    switch (fourcc) {
      case GST_MAKE_FOURCC ('I', '4', '2', '0'):
        ret = _("Uncompressed planar YUV 4:2:0");
        break;
      case GST_MAKE_FOURCC ('Y', 'V', '1', '2'):
        ret = _("Uncompressed planar YVU 4:2:0");
        break;
      case GST_MAKE_FOURCC ('Y', 'U', 'Y', '2'):
        ret = _("Uncompressed packed YUV 4:2:2");
        break;
      case GST_MAKE_FOURCC ('Y', 'U', 'V', '9'):
        ret = _("Uncompressed packed YUV 4:1:0");
        break;
      case GST_MAKE_FOURCC ('Y', 'V', 'U', '9'):
        ret = _("Uncompressed packed YVU 4:1:0");
        break;
      case GST_MAKE_FOURCC ('Y', 'V', 'Y', 'U'):
      case GST_MAKE_FOURCC ('U', 'Y', 'V', 'Y'):
        ret = _("Uncompressed packed YUV 4:2:2");
        break;
      case GST_MAKE_FOURCC ('Y', '4', '1', 'P'):
        ret = _("Uncompressed packed YUV 4:1:1");
        break;
      case GST_MAKE_FOURCC ('I', 'Y', 'U', '2'):
        ret = _("Uncompressed packed YUV 4:4:4");
        break;
      case GST_MAKE_FOURCC ('Y', '4', '2', 'B'):
        ret = _("Uncompressed planar YUV 4:2:2");
        break;
      case GST_MAKE_FOURCC ('Y', '4', '1', 'B'):
        ret = _("Uncompressed planar YUV 4:1:1");
        break;
      case GST_MAKE_FOURCC ('Y', '8', '0', '0'):
        ret = _("Uncompressed black and white Y-plane");
        break;
      default:
        ret = _("Uncompressed YUV");
        break;
    }
    return g_strdup (ret);
  } else if (strcmp (info->type, "video/x-raw-rgb") == 0) {
    const gchar *rgb_str;
    gint depth = 0;

    gst_structure_get_int (s, "depth", &depth);
    rgb_str = gst_structure_has_field (s, "alpha_mask") ? "RGBA" : "RGB";
    if (gst_structure_has_field (s, "paletted_data")) {
      return g_strdup_printf (_("Uncompressed palettized %d-bit %s"), depth,
          rgb_str);
    } else {
      return g_strdup_printf ("Uncompressed %d-bit %s", depth, rgb_str);
    }
  } else if (strcmp (info->type, "video/x-h263") == 0) {
    const gchar *variant, *ret;

    variant = gst_structure_get_string (s, "variant");
    if (variant == NULL)
      ret = "H.263";
    else if (strcmp (variant, "itu") == 0)
      ret = "ITU H.26n";        /* why not ITU H.263? (tpm) */
    else if (strcmp (variant, "lead") == 0)
      ret = "Lead H.263";
    else if (strcmp (variant, "microsoft") == 0)
      ret = "Microsoft H.263";
    else if (strcmp (variant, "vdolive") == 0)
      ret = "VDOLive";
    else if (strcmp (variant, "vivo") == 0)
      ret = "Vivo H.263";
    else if (strcmp (variant, "xirlink") == 0)
      ret = "Xirlink H.263";
    else {
      GST_WARNING ("Unknown H263 variant '%s'", variant);
      ret = "H.263";
    }
    return g_strdup (ret);
  } else if (strcmp (info->type, "video/x-h264") == 0) {
    const gchar *variant, *ret;

    variant = gst_structure_get_string (s, "variant");
    if (variant == NULL)
      ret = "H.264";
//.........这里部分代码省略.........

static gpointer
init_devices (gpointer data)
{
  IDeckLinkIterator *iterator;
  IDeckLink *decklink = NULL;
  HRESULT ret;
  int i;

#ifdef _MSC_VER
  // Start COM thread for Windows

  g_mutex_lock (&com_init_lock);

  /* create the COM initialization thread */
  g_thread_create ((GThreadFunc) gst_decklink_com_thread, NULL, FALSE, NULL);

  /* wait until the COM thread signals that COM has been initialized */
  g_cond_wait (&com_init_cond, &com_init_lock);
  g_mutex_unlock (&com_init_lock);
#endif /* _MSC_VER */

  iterator = CreateDeckLinkIteratorInstance ();
  if (iterator == NULL) {
    GST_ERROR ("no driver");
    return NULL;
  }

  i = 0;
  ret = iterator->Next (&decklink);
  while (ret == S_OK) {
    ret = decklink->QueryInterface (IID_IDeckLinkInput,
        (void **) &devices[i].input.input);
    if (ret != S_OK) {
      GST_WARNING ("selected device does not have input interface");
    } else {
      devices[i].input.device = decklink;
      devices[i].input.clock = gst_decklink_clock_new ("GstDecklinkInputClock");
      GST_DECKLINK_CLOCK_CAST (devices[i].input.clock)->input =
          &devices[i].input;
      devices[i].input.
          input->SetCallback (new GStreamerDecklinkInputCallback (&devices[i].
              input));
    }

    ret = decklink->QueryInterface (IID_IDeckLinkOutput,
        (void **) &devices[i].output.output);
    if (ret != S_OK) {
      GST_WARNING ("selected device does not have output interface");
    } else {
      devices[i].output.device = decklink;
      devices[i].output.clock =
          gst_decklink_clock_new ("GstDecklinkOutputClock");
      GST_DECKLINK_CLOCK_CAST (devices[i].output.clock)->output =
          &devices[i].output;
    }

    ret = decklink->QueryInterface (IID_IDeckLinkConfiguration,
        (void **) &devices[i].input.config);
    if (ret != S_OK) {
      GST_WARNING ("selected device does not have config interface");
    }

    ret = decklink->QueryInterface (IID_IDeckLinkAttributes,
        (void **) &devices[i].input.attributes);
    if (ret != S_OK) {
      GST_WARNING ("selected device does not have attributes interface");
    }

    ret = iterator->Next (&decklink);
    i++;

    if (i == 10) {
      GST_WARNING ("this hardware has more then 10 devices");
      break;
    }
  }

  n_devices = i;

  iterator->Release ();

  return NULL;
}

/* This function checks that it is actually really possible to create an image
   using XShm */
gboolean
gst_ximagesink_check_xshm_calls (GstXImageSink * ximagesink,
    GstXContext * xcontext)
{
  XImage *ximage;
  XShmSegmentInfo SHMInfo;
  size_t size;
  int (*handler) (Display *, XErrorEvent *);
  gboolean result = FALSE;
  gboolean did_attach = FALSE;

  g_return_val_if_fail (xcontext != NULL, FALSE);

  /* Sync to ensure any older errors are already processed */
  XSync (xcontext->disp, FALSE);

  /* Set defaults so we don't free these later unnecessarily */
  SHMInfo.shmaddr = ((void *) -1);
  SHMInfo.shmid = -1;

  /* Setting an error handler to catch failure */
  error_caught = FALSE;
  handler = XSetErrorHandler (gst_ximagesink_handle_xerror);

  /* Trying to create a 1x1 ximage */
  GST_DEBUG ("XShmCreateImage of 1x1");

  ximage = XShmCreateImage (xcontext->disp, xcontext->visual,
      xcontext->depth, ZPixmap, NULL, &SHMInfo, 1, 1);

  /* Might cause an error, sync to ensure it is noticed */
  XSync (xcontext->disp, FALSE);
  if (!ximage || error_caught) {
    GST_WARNING ("could not XShmCreateImage a 1x1 image");
    goto beach;
  }
  size = ximage->height * ximage->bytes_per_line;

  SHMInfo.shmid = shmget (IPC_PRIVATE, size, IPC_CREAT | 0777);
  if (SHMInfo.shmid == -1) {
    GST_WARNING ("could not get shared memory of %" G_GSIZE_FORMAT " bytes",
        size);
    goto beach;
  }

  SHMInfo.shmaddr = shmat (SHMInfo.shmid, NULL, 0);
  if (SHMInfo.shmaddr == ((void *) -1)) {
    GST_WARNING ("Failed to shmat: %s", g_strerror (errno));
    /* Clean up the shared memory segment */
    shmctl (SHMInfo.shmid, IPC_RMID, NULL);
    goto beach;
  }

  ximage->data = SHMInfo.shmaddr;
  SHMInfo.readOnly = FALSE;

  if (XShmAttach (xcontext->disp, &SHMInfo) == 0) {
    GST_WARNING ("Failed to XShmAttach");
    /* Clean up the shared memory segment */
    shmctl (SHMInfo.shmid, IPC_RMID, NULL);
    goto beach;
  }

  /* Sync to ensure we see any errors we caused */
  XSync (xcontext->disp, FALSE);

  /* Delete the shared memory segment as soon as everyone is attached.
   * This way, it will be deleted as soon as we detach later, and not
   * leaked if we crash. */
  shmctl (SHMInfo.shmid, IPC_RMID, NULL);

  if (!error_caught) {
    GST_DEBUG ("XServer ShmAttached to 0x%x, id 0x%lx", SHMInfo.shmid,
        SHMInfo.shmseg);

    did_attach = TRUE;
    /* store whether we succeeded in result */
    result = TRUE;
  } else {
    GST_WARNING ("MIT-SHM extension check failed at XShmAttach. "
        "Not using shared memory.");
  }

beach:
  /* Sync to ensure we swallow any errors we caused and reset error_caught */
  XSync (xcontext->disp, FALSE);

  error_caught = FALSE;
  XSetErrorHandler (handler);

  if (did_attach) {
    GST_DEBUG ("XServer ShmDetaching from 0x%x id 0x%lx",
        SHMInfo.shmid, SHMInfo.shmseg);
    XShmDetach (xcontext->disp, &SHMInfo);
    XSync (xcontext->disp, FALSE);
  }
  if (SHMInfo.shmaddr != ((void *) -1))
    shmdt (SHMInfo.shmaddr);
//.........这里部分代码省略.........

static gboolean
gst_vdp_mpeg4_dec_handle_configuration (GstVdpMpeg4Dec * mpeg4_dec,
    GstMpeg4Frame * mpeg4_frame)
{
  Mpeg4VisualObjectSequence vos;
  Mpeg4VisualObject vo;
  Mpeg4VideoObjectLayer vol;

  GstVideoState state;
  guint8 profile_indication;
  VdpDecoderProfile profile;

  GstFlowReturn ret;

  if (mpeg4_dec->is_configured)
    return GST_FLOW_OK;

  if (!mpeg4_frame->vos_buf || !mpeg4_frame->vo_buf || !mpeg4_frame->vol_buf)
    goto skip_frame;

  if (!mpeg4_util_parse_VOS (mpeg4_frame->vos_buf, &vos))
    goto skip_frame;

  if (!mpeg4_util_parse_VO (mpeg4_frame->vo_buf, &vo))
    goto skip_frame;

  if (!mpeg4_util_parse_VOL (mpeg4_frame->vol_buf, &vo, &vol))
    goto skip_frame;

  state = gst_base_video_decoder_get_state (GST_BASE_VIDEO_DECODER (mpeg4_dec));

  state.width = vol.width;
  state.height = vol.height;

  if (vol.fixed_vop_rate) {
    state.fps_n = vol.vop_time_increment_resolution;
    state.fps_d = vol.fixed_vop_time_increment;
  }

  state.par_n = vol.par_n;
  state.par_d = vol.par_d;

  gst_base_video_decoder_set_state (GST_BASE_VIDEO_DECODER (mpeg4_dec), state);

  profile_indication = vos.profile_and_level_indication >> 4;
  switch (profile_indication) {
    case 0x0:
      profile = VDP_DECODER_PROFILE_MPEG4_PART2_SP;
      break;

    case 0xf:
      profile = VDP_DECODER_PROFILE_MPEG4_PART2_ASP;
      break;

    default:
      goto unsupported_profile;
  }
  ret = gst_vdp_decoder_init_decoder (GST_VDP_DECODER (mpeg4_dec), profile, 2);
  if (ret != GST_FLOW_OK)
    return ret;

  mpeg4_dec->vol = vol;
  mpeg4_dec->is_configured = TRUE;

  return GST_FLOW_OK;

skip_frame:
  GST_WARNING ("Skipping frame since we're not configured yet");
  gst_base_video_decoder_skip_frame (GST_BASE_VIDEO_DECODER (mpeg4_dec),
      GST_VIDEO_FRAME (mpeg4_frame));
  return GST_FLOW_CUSTOM_ERROR;

unsupported_profile:
  GST_ELEMENT_ERROR (mpeg4_dec, STREAM, WRONG_TYPE,
      ("vdpaumpeg4dec doesn't support this streams profile"),
      ("profile_and_level_indication: %d", vos.profile_and_level_indication));
  return GST_FLOW_ERROR;
}

//.........这里部分代码省略.........
            return GST_VAAPI_DECODER_STATUS_ERROR_NO_DATA;
        }
        ofs += seg.size;

        /* Decode scan, if complete */
        if (seg.marker == GST_JPEG_MARKER_EOI && scan_seg.header_size > 0) {
            scan_seg.data_size = seg.offset - scan_seg.data_offset;
            scan_seg.is_valid  = TRUE;
        }
        if (scan_seg.is_valid) {
            status = decode_scan(
                decoder,
                buf + scan_seg.header_offset,
                scan_seg.header_size,
                buf + scan_seg.data_offset,
                scan_seg.data_size
            );
            if (status != GST_VAAPI_DECODER_STATUS_SUCCESS)
                break;
            memset(&scan_seg, 0, sizeof(scan_seg));
        }

        append_ecs = TRUE;
        switch (seg.marker) {
        case GST_JPEG_MARKER_SOI:
            priv->has_quant_table = FALSE;
            priv->has_huf_table   = FALSE;
            priv->mcu_restart     = 0;
            status = GST_VAAPI_DECODER_STATUS_SUCCESS;
            break;
        case GST_JPEG_MARKER_EOI:
            if (decode_current_picture(decoder)) {
                /* Get out of the loop, trailing data is not needed */
                status = GST_VAAPI_DECODER_STATUS_SUCCESS;
                goto end;
            }
            status = GST_VAAPI_DECODER_STATUS_ERROR_UNKNOWN;
            break;
        case GST_JPEG_MARKER_DHT:
            status = decode_huffman_table(decoder, buf + seg.offset, seg.size);
            break;
        case GST_JPEG_MARKER_DQT:
            status = decode_quant_table(decoder, buf + seg.offset, seg.size);
            break;
        case GST_JPEG_MARKER_DRI:
            status = decode_restart_interval(decoder, buf + seg.offset, seg.size);
            break;
        case GST_JPEG_MARKER_DAC:
            GST_ERROR("unsupported arithmetic coding mode");
            status = GST_VAAPI_DECODER_STATUS_ERROR_UNSUPPORTED_PROFILE;
            break;
        case GST_JPEG_MARKER_SOS:
            scan_seg.header_offset = seg.offset;
            scan_seg.header_size   = seg.size;
            scan_seg.data_offset   = seg.offset + seg.size;
            scan_seg.data_size     = 0;
            append_ecs             = FALSE;
            break;
        default:
            /* Restart marker */
            if (seg.marker >= GST_JPEG_MARKER_RST_MIN &&
                seg.marker <= GST_JPEG_MARKER_RST_MAX) {
                append_ecs = FALSE;
                break;
            }

            /* Frame header */
            if (seg.marker >= GST_JPEG_MARKER_SOF_MIN &&
                seg.marker <= GST_JPEG_MARKER_SOF_MAX) {
                status = decode_picture(
                    decoder,
                    seg.marker,
                    buf + seg.offset, seg.size,
                    pts
                );
                break;
            }

            /* Application segments */
            if (seg.marker >= GST_JPEG_MARKER_APP_MIN &&
                seg.marker <= GST_JPEG_MARKER_APP_MAX) {
                status = GST_VAAPI_DECODER_STATUS_SUCCESS;
                break;
            }

            GST_WARNING("unsupported marker (0x%02x)", seg.marker);
            status = GST_VAAPI_DECODER_STATUS_ERROR_BITSTREAM_PARSER;
            break;
        }

        /* Append entropy coded segments */
        if (append_ecs)
            scan_seg.data_size = seg.offset - scan_seg.data_offset;

        if (status != GST_VAAPI_DECODER_STATUS_SUCCESS)
            break;
    }
end:
    return status;
}

void
gst_aiur_stream_cache_add_buffer (GstAiurStreamCache * cache,
    GstBuffer * buffer)
{
  guint64 size;
  gint trycnt = 0;
  if ((cache == NULL) || (buffer == NULL))
    goto bail;

  g_mutex_lock (cache->mutex);

  size = GST_BUFFER_SIZE (buffer);

  if ((cache->seeking) || (size == 0)) {
    g_mutex_unlock (cache->mutex);
    goto bail;
  }

  if (cache->ignore_size) {
    /* drop part or total buffer */
    if (cache->ignore_size >= size) {
      cache->ignore_size -= size;
      g_mutex_unlock (cache->mutex);
      goto bail;
    } else {
      GST_BUFFER_DATA (buffer) += (cache->ignore_size);
      GST_BUFFER_SIZE (buffer) -= (cache->ignore_size);
      size = GST_BUFFER_SIZE (buffer);
      cache->ignore_size = 0;
    }
    //g_print("cache offset %lld\n", cache->offset);
  }

  gst_adapter_push (cache->adapter, buffer);
  g_cond_signal (cache->produce_cond);

  buffer = NULL;

  if (cache->threshold_max) {
#if 0
    if (cache->threshold_max < size + cache->threshold_pre) {
      cache->threshold_max = size + cache->threshold_pre;
    }
#endif

    while ((gst_adapter_available (cache->adapter) > cache->threshold_max)
        && (cache->closed == FALSE)) {
      if (((++trycnt) & 0x1f) == 0x0) {
        GST_WARNING ("wait push try %d SIZE %d %lld", trycnt,
            gst_adapter_available (cache->adapter), cache->threshold_max);
      }
      WAIT_COND_TIMEOUT (cache->consume_cond, cache->mutex, 1000000);
    }

    if (cache->seeking) {
      g_mutex_unlock (cache->mutex);
      goto bail;
    }
  }


  g_mutex_unlock (cache->mutex);

  return;

bail:
  if (buffer) {
    gst_buffer_unref (buffer);
  }
}

static gboolean
get_video_recv_info (KmsRembLocal * rl,
    guint64 * bitrate, guint * fraction_lost, guint64 * packets_rcv_interval)
{
  GValueArray *arr = NULL;
  GValue *val;
  guint i;
  gboolean ret = FALSE;

  if (!KMS_REMB_BASE (rl)->rtpsess) {
    GST_WARNING ("Session object does not exist");
    return ret;
  }

  g_object_get (KMS_REMB_BASE (rl)->rtpsess, "sources", &arr, NULL);

  if (arr == NULL) {
    GST_WARNING ("Sources array not found");
    return ret;
  }

  for (i = 0; i < arr->n_values; i++) {
    GObject *source;
    guint ssrc;
    GstStructure *s;

    val = g_value_array_get_nth (arr, i);
    source = g_value_get_object (val);
    g_object_get (source, "ssrc", &ssrc, "stats", &s, NULL);

    GST_TRACE_OBJECT (source, "source ssrc: %u", ssrc);
    GST_TRACE_OBJECT (KMS_REMB_BASE (rl)->rtpsess, "stats: %" GST_PTR_FORMAT,
        s);

    if (ssrc == rl->remote_ssrc) {
      GstClockTime current_time;
      guint64 octets_received, packets_received;

      if (!gst_structure_get_uint64 (s, "bitrate", bitrate)) {
        break;
      }
      if (!gst_structure_get_uint64 (s, "octets-received", &octets_received)) {
        break;
      }
      if (!gst_structure_get_uint (s, "sent-rb-fractionlost", fraction_lost)) {
        break;
      }
      if (!gst_structure_get_uint64 (s, "packets-received", &packets_received)) {
        break;
      }

      current_time = kms_utils_get_time_nsecs ();

      if (rl->last_time != 0) {
        GstClockTime elapsed = current_time - rl->last_time;
        guint64 bytes_handled = octets_received - rl->last_octets_received;

        *bitrate =
            gst_util_uint64_scale (bytes_handled, 8 * GST_SECOND, elapsed);
        GST_TRACE_OBJECT (KMS_REMB_BASE (rl)->rtpsess,
            "Elapsed %" G_GUINT64_FORMAT " bytes %" G_GUINT64_FORMAT ", rate %"
            G_GUINT64_FORMAT, elapsed, bytes_handled, *bitrate);
      }

      rl->last_time = current_time;
      rl->last_octets_received = octets_received;

      *packets_rcv_interval = packets_received - rl->last_packets_received;
      rl->last_packets_received = packets_received;

      ret = TRUE;
    }

    gst_structure_free (s);

    if (ret) {
      break;
    }
  }

  g_value_array_free (arr);

  return ret;
}

static void
on_sending_rtcp (GObject * sess, GstBuffer * buffer, gboolean is_early,
    gboolean * do_not_supress)
{
  KmsRembLocal *rl;
  KmsRTCPPSFBAFBREMBPacket remb_packet;
  GstRTCPBuffer rtcp = { NULL, };
  GstRTCPPacket packet;
  guint packet_ssrc;

  rl = g_object_get_data (sess, KMS_REMB_LOCAL);

  if (!rl) {
    GST_WARNING ("Invalid RembLocal");
    return;
  }

  if (is_early) {
    return;
  }

  if (!gst_rtcp_buffer_map (buffer, GST_MAP_READWRITE, &rtcp)) {
    GST_WARNING_OBJECT (sess, "Cannot map buffer to RTCP");
    return;
  }

  if (!gst_rtcp_buffer_add_packet (&rtcp, GST_RTCP_TYPE_PSFB, &packet)) {
    GST_WARNING_OBJECT (sess, "Cannot add RTCP packet");
    goto end;
  }

  if (!kms_remb_local_update (rl)) {
    goto end;
  }

  remb_packet.bitrate = rl->remb;
  if (rl->event_manager != NULL) {
    guint remb_local_max;

    remb_local_max = kms_utils_remb_event_manager_get_min (rl->event_manager);
    if (remb_local_max > 0) {
      GST_TRACE_OBJECT (sess, "REMB local max: %" G_GUINT32_FORMAT,
          remb_local_max);
      remb_packet.bitrate = MIN (remb_local_max, rl->remb);
    }
  }

  if (rl->min_bw > 0) {
    remb_packet.bitrate = MAX (remb_packet.bitrate, rl->min_bw * 1000);
  } else {
    remb_packet.bitrate = MAX (remb_packet.bitrate, REMB_MIN);
  }

  remb_packet.n_ssrcs = 1;
  remb_packet.ssrcs[0] = rl->remote_ssrc;
  g_object_get (sess, "internal-ssrc", &packet_ssrc, NULL);
  if (!kms_rtcp_psfb_afb_remb_marshall_packet (&packet, &remb_packet,
          packet_ssrc)) {
    gst_rtcp_packet_remove (&packet);
  }

  GST_TRACE_OBJECT (sess, "Sending REMB (bitrate: %" G_GUINT32_FORMAT
      ", ssrc: %" G_GUINT32_FORMAT ")", remb_packet.bitrate, rl->remote_ssrc);

  kms_remb_base_update_stats (KMS_REMB_BASE (rl), rl->remote_ssrc,
      remb_packet.bitrate);

end:
  gst_rtcp_buffer_unmap (&rtcp);
}

/**
 * rtp_jitter_buffer_insert:
 * @jbuf: an #RTPJitterBuffer
 * @buf: a buffer
 * @time: a running_time when this buffer was received in nanoseconds
 * @clock_rate: the clock-rate of the payload of @buf
 * @max_delay: the maximum lateness of @buf
 * @tail: TRUE when the tail element changed.
 *
 * Inserts @buf into the packet queue of @jbuf. The sequence number of the
 * packet will be used to sort the packets. This function takes ownerhip of
 * @buf when the function returns %TRUE.
 * @buf should have writable metadata when calling this function.
 *
 * Returns: %FALSE if a packet with the same number already existed.
 */
gboolean
rtp_jitter_buffer_insert (RTPJitterBuffer * jbuf, GstBuffer * buf,
    GstClockTime time, guint32 clock_rate, gboolean * tail, gint * percent)
{
  GList *list;
  guint32 rtptime;
  guint16 seqnum;
  GstRTPBuffer rtp = {NULL};

  g_return_val_if_fail (jbuf != NULL, FALSE);
  g_return_val_if_fail (buf != NULL, FALSE);

  gst_rtp_buffer_map (buf, GST_MAP_READ, &rtp);

  seqnum = gst_rtp_buffer_get_seq (&rtp);

  /* loop the list to skip strictly smaller seqnum buffers */
  for (list = jbuf->packets->head; list; list = g_list_next (list)) {
    guint16 qseq;
    gint gap;
    GstRTPBuffer rtpb = {NULL};

    gst_rtp_buffer_map (GST_BUFFER_CAST (list->data), GST_MAP_READ, &rtpb);
    qseq = gst_rtp_buffer_get_seq (&rtpb);
    gst_rtp_buffer_unmap (&rtpb);

    /* compare the new seqnum to the one in the buffer */
    gap = gst_rtp_buffer_compare_seqnum (seqnum, qseq);

    /* we hit a packet with the same seqnum, notify a duplicate */
    if (G_UNLIKELY (gap == 0))
      goto duplicate;

    /* seqnum > qseq, we can stop looking */
    if (G_LIKELY (gap < 0))
      break;
  }

  rtptime = gst_rtp_buffer_get_timestamp (&rtp);
  /* rtp time jumps are checked for during skew calculation, but bypassed
   * in other mode, so mind those here and reset jb if needed.
   * Only reset if valid input time, which is likely for UDP input
   * where we expect this might happen due to async thread effects
   * (in seek and state change cycles), but not so much for TCP input */
  if (GST_CLOCK_TIME_IS_VALID (time) &&
      jbuf->mode != RTP_JITTER_BUFFER_MODE_SLAVE &&
      jbuf->base_time != -1 && jbuf->last_rtptime != -1) {
    GstClockTime ext_rtptime = jbuf->ext_rtptime;

    ext_rtptime = gst_rtp_buffer_ext_timestamp (&ext_rtptime, rtptime);
    if (ext_rtptime > jbuf->last_rtptime + 3 * clock_rate ||
        ext_rtptime + 3 * clock_rate < jbuf->last_rtptime) {
      /* reset even if we don't have valid incoming time;
       * still better than producing possibly very bogus output timestamp */
      GST_WARNING ("rtp delta too big, reset skew");
      rtp_jitter_buffer_reset_skew (jbuf);
    }
  }

  switch (jbuf->mode) {
    case RTP_JITTER_BUFFER_MODE_NONE:
    case RTP_JITTER_BUFFER_MODE_BUFFER:
      /* send 0 as the first timestamp and -1 for the other ones. This will
       * interpollate them from the RTP timestamps with a 0 origin. In buffering
       * mode we will adjust the outgoing timestamps according to the amount of
       * time we spent buffering. */
      if (jbuf->base_time == -1)
        time = 0;
      else
        time = -1;
      break;
    case RTP_JITTER_BUFFER_MODE_SLAVE:
    default:
      break;
  }
  /* do skew calculation by measuring the difference between rtptime and the
   * receive time, this function will retimestamp @buf with the skew corrected
   * running time. */
  time = calculate_skew (jbuf, rtptime, time, clock_rate);
  GST_BUFFER_TIMESTAMP (buf) = time;

  /* It's more likely that the packet was inserted in the front of the buffer */
  if (G_LIKELY (list))
    g_queue_insert_before (jbuf->packets, list, buf);
//.........这里部分代码省略.........