C++ GST_BUFFER_DATA函数代码示例

static void
play_loop (GstPad * pad)
{
  GstFlowReturn ret;
  GstNsfDec *nsfdec;
  GstBuffer *out;
  gint64 value, offset, time;
  GstFormat format;

  nsfdec = GST_NSFDEC (gst_pad_get_parent (pad));

  out = gst_buffer_new_and_alloc (nsfdec->blocksize);
  gst_buffer_set_caps (out, GST_PAD_CAPS (pad));

  nsf_frame (nsfdec->nsf);
  apu_process (GST_BUFFER_DATA (out), nsfdec->blocksize / nsfdec->bps);

  /* get offset in samples */
  format = GST_FORMAT_DEFAULT;
  gst_nsfdec_src_convert (nsfdec->srcpad,
      GST_FORMAT_BYTES, nsfdec->total_bytes, &format, &offset);
  GST_BUFFER_OFFSET (out) = offset;

  /* get current timestamp */
  format = GST_FORMAT_TIME;
  gst_nsfdec_src_convert (nsfdec->srcpad,
      GST_FORMAT_BYTES, nsfdec->total_bytes, &format, &time);
  GST_BUFFER_TIMESTAMP (out) = time;

  /* update position and get new timestamp to calculate duration */
  nsfdec->total_bytes += nsfdec->blocksize;

  /* get offset in samples */
  format = GST_FORMAT_DEFAULT;
  gst_nsfdec_src_convert (nsfdec->srcpad,
      GST_FORMAT_BYTES, nsfdec->total_bytes, &format, &value);
  GST_BUFFER_OFFSET_END (out) = value;

  format = GST_FORMAT_TIME;
  gst_nsfdec_src_convert (nsfdec->srcpad,
      GST_FORMAT_BYTES, nsfdec->total_bytes, &format, &value);
  GST_BUFFER_DURATION (out) = value - time;

  if ((ret = gst_pad_push (nsfdec->srcpad, out)) != GST_FLOW_OK)
    goto pause;

done:
  gst_object_unref (nsfdec);

  return;

  /* ERRORS */
pause:
  {
    const gchar *reason = gst_flow_get_name (ret);

    GST_DEBUG_OBJECT (nsfdec, "pausing task, reason %s", reason);
    gst_pad_pause_task (pad);

    if (ret == GST_FLOW_UNEXPECTED) {
      /* perform EOS logic, FIXME, segment seek? */
      gst_pad_push_event (pad, gst_event_new_eos ());
    } else if (ret == GST_FLOW_NOT_LINKED || ret < GST_FLOW_UNEXPECTED) {
      /* for fatal errors we post an error message */
      GST_ELEMENT_ERROR (nsfdec, STREAM, FAILED,
          (NULL), ("streaming task paused, reason %s", reason));
      gst_pad_push_event (pad, gst_event_new_eos ());
    }
    goto done;
  }
}

static GstFlowReturn
gst_video_mark_yuv (GstVideoMark * videomark, GstBuffer * buffer)
{
  GstVideoFormat format;
  gint i, pw, ph, row_stride, pixel_stride, offset;
  gint width, height, req_width, req_height;
  guint8 *d, *data;
  guint64 pattern_shift;
  guint8 color;

  data = GST_BUFFER_DATA (buffer);

  format = videomark->format;
  width = videomark->width;
  height = videomark->height;

  pw = videomark->pattern_width;
  ph = videomark->pattern_height;
  row_stride = gst_video_format_get_row_stride (format, 0, width);
  pixel_stride = gst_video_format_get_pixel_stride (format, 0);
  offset = gst_video_format_get_component_offset (format, 0, width, height);

  req_width =
      (videomark->pattern_count + videomark->pattern_data_count) * pw +
      videomark->left_offset;
  req_height = videomark->bottom_offset + ph;
  if (req_width > width || req_height > height) {
    GST_ELEMENT_ERROR (videomark, STREAM, WRONG_TYPE, (NULL),
        ("videomark pattern doesn't fit video, need at least %ix%i (stream has %ix%i)",
            req_width, req_height, width, height));
    return GST_FLOW_ERROR;
  }

  /* draw the bottom left pixels */
  for (i = 0; i < videomark->pattern_count; i++) {
    d = data + offset;
    /* move to start of bottom left */
    d += row_stride * (height - ph - videomark->bottom_offset) +
        pixel_stride * videomark->left_offset;
    /* move to i-th pattern */
    d += pixel_stride * pw * i;

    if (i & 1)
      /* odd pixels must be white */
      color = 255;
    else
      color = 0;

    /* draw box of width * height */
    gst_video_mark_draw_box (videomark, d, pw, ph, row_stride, pixel_stride,
        color);
  }

  pattern_shift = G_GUINT64_CONSTANT (1) << (videomark->pattern_data_count - 1);

  /* get the data of the pattern */
  for (i = 0; i < videomark->pattern_data_count; i++) {
    d = data + offset;
    /* move to start of bottom left, adjust for offsets */
    d += row_stride * (height - ph - videomark->bottom_offset) +
        pixel_stride * videomark->left_offset;
    /* move after the fixed pattern */
    d += pixel_stride * videomark->pattern_count * pw;
    /* move to i-th pattern data */
    d += pixel_stride * pw * i;

    if (videomark->pattern_data & pattern_shift)
      color = 255;
    else
      color = 0;

    gst_video_mark_draw_box (videomark, d, pw, ph, row_stride, pixel_stride,
        color);

    pattern_shift >>= 1;
  }

  return GST_FLOW_OK;
}

bool nvxio::GStreamerBaseRenderImpl::flush()
{
    if (!pipeline)
        return false;

    glfwMakeContextCurrent(window_);

    if (glfwWindowShouldClose(window_))
        return false;

    gl_->PixelStorei(GL_PACK_ALIGNMENT, 1);
    gl_->PixelStorei(GL_PACK_ROW_LENGTH, wndWidth_);

    {
        GstClockTime duration = GST_SECOND / (double)GSTREAMER_DEFAULT_FPS;
        GstClockTime timestamp = num_frames * duration;

#if GST_VERSION_MAJOR == 0
        GstBuffer * buffer = gst_buffer_try_new_and_alloc(wndHeight_ * wndWidth_ * 4);
        if (!buffer)
        {
            NVXIO_PRINT("Cannot create GStreamer buffer");
            FinalizeGStreamerPipeline();
            return false;
        }

        gl_->ReadPixels(0, 0, wndWidth_, wndHeight_, GL_RGBA, GL_UNSIGNED_BYTE, GST_BUFFER_DATA (buffer));

        GST_BUFFER_TIMESTAMP(buffer) = timestamp;
        if (!GST_BUFFER_TIMESTAMP_IS_VALID(buffer))
            NVXIO_PRINT("Failed to setup timestamp");
#else
        GstBuffer * buffer = gst_buffer_new_allocate(NULL, wndHeight_ * wndWidth_ * 4, NULL);

        GstMapInfo info;
        gst_buffer_map(buffer, &info, GST_MAP_READ);
        gl_->ReadPixels(0, 0, wndWidth_, wndHeight_, GL_RGBA, GL_UNSIGNED_BYTE, info.data);
        gst_buffer_unmap(buffer, &info);

        GST_BUFFER_PTS(buffer) = timestamp;
        if (!GST_BUFFER_PTS_IS_VALID(buffer))
            NVXIO_PRINT("Failed to setup PTS");

        GST_BUFFER_DTS(buffer) = timestamp;
        if (!GST_BUFFER_DTS_IS_VALID(buffer))
            NVXIO_PRINT("Failed to setup DTS");
#endif
        GST_BUFFER_DURATION(buffer) = duration;
        if (!GST_BUFFER_DURATION_IS_VALID(buffer))
            NVXIO_PRINT("Failed to setup duration");

        GST_BUFFER_OFFSET(buffer) = num_frames++;
        if (!GST_BUFFER_OFFSET_IS_VALID(buffer))
            NVXIO_PRINT("Failed to setup offset");

        if (gst_app_src_push_buffer(appsrc, buffer) != GST_FLOW_OK)
        {
            NVXIO_PRINT("Error pushing buffer to GStreamer pipeline");
            FinalizeGStreamerPipeline();
            return false;
        }
    }

    // reset state
    gl_->PixelStorei(GL_PACK_ALIGNMENT, 4);
    gl_->PixelStorei(GL_PACK_ROW_LENGTH, 0);

    glfwSwapBuffers(window_);

    clearGlBuffer();

    return true;
}

HRESULT AudioFakeSink::DoRenderSample(IMediaSample *pMediaSample)
{
  GstBuffer *out_buf = NULL;
  gboolean in_seg = FALSE;
  GstClockTime buf_start, buf_stop;
  gint64 clip_start = 0, clip_stop = 0;
  guint start_offset = 0, stop_offset;
  GstClockTime duration;

  if(pMediaSample)
  {
    BYTE *pBuffer = NULL;
    LONGLONG lStart = 0, lStop = 0;
    long size = pMediaSample->GetActualDataLength();

    pMediaSample->GetPointer(&pBuffer);
    pMediaSample->GetTime(&lStart, &lStop);
    
    if (!GST_CLOCK_TIME_IS_VALID (mDec->timestamp)) {
      // Convert REFERENCE_TIME to GST_CLOCK_TIME
      mDec->timestamp = (GstClockTime)lStart * 100;
    }
    duration = (lStop - lStart) * 100;

    buf_start = mDec->timestamp;
    buf_stop = mDec->timestamp + duration;

    /* save stop position to start next buffer with it */
    mDec->timestamp = buf_stop;

    /* check if this buffer is in our current segment */
    in_seg = gst_segment_clip (mDec->segment, GST_FORMAT_TIME,
        buf_start, buf_stop, &clip_start, &clip_stop);

    /* if the buffer is out of segment do not push it downstream */
    if (!in_seg) {
      GST_DEBUG_OBJECT (mDec,
          "buffer is out of segment, start %" GST_TIME_FORMAT " stop %"
          GST_TIME_FORMAT, GST_TIME_ARGS (buf_start), GST_TIME_ARGS (buf_stop));
      goto done;
    }

    /* buffer is entirely or partially in-segment, so allocate a
     * GstBuffer for output, and clip if required */

    /* allocate a new buffer for raw audio */
    mDec->last_ret = gst_pad_alloc_buffer (mDec->srcpad, 
        GST_BUFFER_OFFSET_NONE,
        size,
        GST_PAD_CAPS (mDec->srcpad), &out_buf);
    if (!out_buf) {
      GST_WARNING_OBJECT (mDec, "cannot allocate a new GstBuffer");
      goto done;
    }

    /* set buffer properties */
    GST_BUFFER_TIMESTAMP (out_buf) = buf_start;
    GST_BUFFER_DURATION (out_buf) = duration;
    memcpy (GST_BUFFER_DATA (out_buf), pBuffer,
        MIN ((unsigned int)size, GST_BUFFER_SIZE (out_buf)));

    /* we have to remove some heading samples */
    if ((GstClockTime) clip_start > buf_start) {
      start_offset = (guint)gst_util_uint64_scale_int (clip_start - buf_start,
          mDec->rate, GST_SECOND) * mDec->depth / 8 * mDec->channels;
    }
    else
      start_offset = 0;
    /* we have to remove some trailing samples */
    if ((GstClockTime) clip_stop < buf_stop) {
      stop_offset = (guint)gst_util_uint64_scale_int (buf_stop - clip_stop,
          mDec->rate, GST_SECOND) * mDec->depth / 8 * mDec->channels;
    }
    else
      stop_offset = size;

    /* truncating */
    if ((start_offset != 0) || (stop_offset != (size_t) size)) {
      GstBuffer *subbuf = gst_buffer_create_sub (out_buf, start_offset,
          stop_offset - start_offset);

      if (subbuf) {
        gst_buffer_set_caps (subbuf, GST_PAD_CAPS (mDec->srcpad));
        gst_buffer_unref (out_buf);
        out_buf = subbuf;
      }
    }

    GST_BUFFER_TIMESTAMP (out_buf) = clip_start;
    GST_BUFFER_DURATION (out_buf) = clip_stop - clip_start;

    /* replace the saved stop position by the clipped one */
    mDec->timestamp = clip_stop;

    GST_DEBUG_OBJECT (mDec,
        "push_buffer (size %d)=> pts %" GST_TIME_FORMAT " stop %" GST_TIME_FORMAT
        " duration %" GST_TIME_FORMAT, size,
        GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (out_buf)),
        GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (out_buf) +
            GST_BUFFER_DURATION (out_buf)),
//.........这里部分代码省略.........

static OSErr
data_proc (SGChannel c, Ptr p, long len, long * offset, long chRefCon,
           TimeValue time, short writeType, long refCon)
{
    GstOSXVideoSrc * self;
    gint fps_n, fps_d;
    GstClockTime duration, timestamp, latency;
    CodecFlags flags;
    ComponentResult err;
    PixMapHandle hPixMap;
    Rect portRect;
    int pix_rowBytes;
    void *pix_ptr;
    int pix_height;
    int pix_size;

    self = GST_OSX_VIDEO_SRC (refCon);

    if (self->buffer != NULL) {
        gst_buffer_unref (self->buffer);
        self->buffer = NULL;
    }

    err = DecompressSequenceFrameS (self->dec_seq, p, len, 0, &flags, NULL);
    if (err != noErr) {
        GST_ERROR_OBJECT (self, "DecompressSequenceFrameS returned %d", (int) err);
        return err;
    }

    hPixMap = GetGWorldPixMap (self->world);
    LockPixels (hPixMap);
    GetPortBounds (self->world, &portRect);
    pix_rowBytes = (int) GetPixRowBytes (hPixMap);
    pix_ptr = GetPixBaseAddr (hPixMap);
    pix_height = (portRect.bottom - portRect.top);
    pix_size = pix_rowBytes * pix_height;

    GST_DEBUG_OBJECT (self, "num=%5d, height=%d, rowBytes=%d, size=%d",
                      self->seq_num, pix_height, pix_rowBytes, pix_size);

    fps_n = FRAMERATE;
    fps_d = 1;

    duration = gst_util_uint64_scale_int (GST_SECOND, fps_d, fps_n);
    latency = duration;

    timestamp = gst_clock_get_time (GST_ELEMENT_CAST (self)->clock);
    timestamp -= gst_element_get_base_time (GST_ELEMENT_CAST (self));
    if (timestamp > latency)
        timestamp -= latency;
    else
        timestamp = 0;

    self->buffer = gst_buffer_new_and_alloc (pix_size);
    GST_BUFFER_OFFSET (self->buffer) = self->seq_num;
    GST_BUFFER_TIMESTAMP (self->buffer) = timestamp;
    memcpy (GST_BUFFER_DATA (self->buffer), pix_ptr, pix_size);

    self->seq_num++;

    UnlockPixels (hPixMap);

    return noErr;
}

static GstFlowReturn
gst_scene_change_filter_ip_I420 (GstVideoFilter2 * videofilter2,
    GstBuffer * buf, int start, int end)
{
  GstSceneChange *scenechange;
  double score_min;
  double score_max;
  double threshold;
  double score;
  gboolean change;
  int i;
  int width;
  int height;

  g_return_val_if_fail (GST_IS_SCENE_CHANGE (videofilter2), GST_FLOW_ERROR);
  scenechange = GST_SCENE_CHANGE (videofilter2);

  width = GST_VIDEO_FILTER2_WIDTH (videofilter2);
  height = GST_VIDEO_FILTER2_HEIGHT (videofilter2);

  if (!scenechange->oldbuf) {
    scenechange->n_diffs = 0;
    memset (scenechange->diffs, 0, sizeof (double) * SC_N_DIFFS);
    scenechange->oldbuf = gst_buffer_ref (buf);
    return GST_FLOW_OK;
  }

  score = get_frame_score (GST_BUFFER_DATA (scenechange->oldbuf),
      GST_BUFFER_DATA (buf), width, height);

  memmove (scenechange->diffs, scenechange->diffs + 1,
      sizeof (double) * (SC_N_DIFFS - 1));
  scenechange->diffs[SC_N_DIFFS - 1] = score;
  scenechange->n_diffs++;

  gst_buffer_unref (scenechange->oldbuf);
  scenechange->oldbuf = gst_buffer_ref (buf);

  score_min = scenechange->diffs[0];
  score_max = scenechange->diffs[0];
  for (i = 1; i < SC_N_DIFFS - 1; i++) {
    score_min = MIN (score_min, scenechange->diffs[i]);
    score_max = MAX (score_max, scenechange->diffs[i]);
  }

  threshold = 1.8 * score_max - 0.8 * score_min;

  if (scenechange->n_diffs > 2) {
    if (score < 5) {
      change = FALSE;
    } else if (score / threshold < 1.0) {
      change = FALSE;
    } else if (score / threshold > 2.5) {
      change = TRUE;
    } else if (score > 50) {
      change = TRUE;
    } else {
      change = FALSE;
    }
  } else {
    change = FALSE;
  }

#ifdef TESTING
  if (change != is_shot_change (scenechange->n_diffs)) {
    g_print ("%d %g %g %g %d\n", scenechange->n_diffs, score / threshold,
        score, threshold, change);
  }
#endif

  if (change) {
    GstEvent *event;

    GST_DEBUG_OBJECT (scenechange, "%d %g %g %g %d",
        scenechange->n_diffs, score / threshold, score, threshold, change);

    event = gst_event_new_custom (GST_EVENT_CUSTOM_DOWNSTREAM,
        gst_structure_new ("GstForceKeyUnit", NULL));

    gst_pad_push_event (GST_BASE_TRANSFORM_SRC_PAD (scenechange), event);
  }

  return GST_FLOW_OK;
}

static GstFlowReturn gst_devsound_src_create(GstBaseSrc *src, guint64 offset,
        guint size, GstBuffer **buf)
    {
    GstDevsoundSrc *dsrc= GST_DEVSOUND_SRC(src);
    int bufferpos=0;
    int ret = KErrNone;
    
    if(!g_queue_get_length(dataqueue) && (dsrc->eosreceived == TRUE))
        {
        pthread_mutex_lock(&(create_mutex1));
        pthread_cond_signal(&(create_condition1));
        pthread_mutex_unlock(&(create_mutex1));
        post_symbian_error( src,KErrCancel );
        return GST_FLOW_UNEXPECTED;
        }
    
    //gst_debug_log(devsound_debug, GST_LEVEL_LOG, "", "", 0, (GObject *) dsrc, "gst_devsound_src_create ENTER ");

    //gst_debug_log(devsound_debug, GST_LEVEL_LOG, "", "", 0, (GObject *) dsrc, "Before Buffer Alloc in CREATE ",NULL);
    *buf = gst_buffer_try_new_and_alloc(size);
    //gst_debug_log(devsound_debug, GST_LEVEL_LOG, "", "", 0, (GObject *) dsrc, "AFter Buffer Alloc in CREATE ",NULL);
    if(*buf == NULL)
    {
        post_symbian_error( src,KErrNoMemory );
        return GST_FLOW_UNEXPECTED;
    }        
    
    while (size > 0)
        {
        if (dataleft >= size)
            {
            // if there is some data left in the popped buffer previously whose size
            // is more then the buffer which is incoming fresh to get filled, fill it
            //here. and if the data left in the popped buffer is 0, then unref it
            //gst_debug_log(devsound_debug, GST_LEVEL_LOG, "", "", 0, (GObject *) dsrc, "dataleft >=size in CREATE ", NULL);
            memcpy(GST_BUFFER_DATA(*buf)+bufferpos,GST_BUFFER_DATA(popBuffer)+dataCopied,size);
            bufferpos+=size;
            dataCopied += size;
            dataleft = GST_BUFFER_SIZE(popBuffer) - dataCopied;
            size = 0;
            if (dataleft == 0)
                {
                dataCopied = 0;
                gst_buffer_unref(popBuffer);
                popBuffer = NULL;
                }
            }
        else
            {
            // if the dataleft in the popped buffer is greater then 0 and  less then
            // the size of data needed for the fresh buffer. copy the remaining data
            // from the popped buffer and then unref it.
            if (dataleft > 0)
                {
                //gst_debug_log(devsound_debug, GST_LEVEL_LOG, "", "", 0, (GObject *) dsrc, "dataleft >0 in CREATE ",NULL);
                memcpy(GST_BUFFER_DATA(*buf)+bufferpos,GST_BUFFER_DATA(popBuffer)+dataCopied,dataleft);
                size -= dataleft;
                bufferpos += dataleft;
                dataCopied = 0;
                dataleft = 0;
                gst_buffer_unref(popBuffer);
                popBuffer = NULL;
                }

            // we wait here if the dataqueue length is 0 and we need data
            // to be filled in the queue from the DevSound Thread
            if (!g_queue_get_length(dataqueue))
                {
                //gst_debug_log(devsound_debug, GST_LEVEL_LOG, "", "", 0, (GObject *) dsrc, "Before WAIT in CREATE ",NULL);
                if(dsrc->eosreceived == TRUE)
                    {
                    post_symbian_error( src,KErrCancel );
                    return GST_FLOW_UNEXPECTED;
                    }
                else
                    {
                    cmd = RECORDING;
                    return_error = KErrNone;
                    pthread_mutex_lock(&(create_mutex1));
                    pthread_cond_signal(&(create_condition1));
                    pthread_mutex_unlock(&(create_mutex1));
                    
                    pthread_mutex_lock(&(create_mutex1));
                    pthread_cond_wait(&(create_condition1), &(create_mutex1));
                    ret = return_error;
                    pthread_mutex_unlock(&(create_mutex1));
                    }
                //gst_debug_log(devsound_debug, GST_LEVEL_LOG, "", "", 0, (GObject *) dsrc, "AFTER WAIT in CREATE ",NULL);
                }
            if( ret )
            { 
                post_symbian_error( src,ret );
                return GST_FLOW_UNEXPECTED;
            }
            //gst_debug_log(devsound_debug, GST_LEVEL_LOG, "", "", 0, (GObject *) dsrc, "Before POP in CREATE ",NULL);
            GST_OBJECT_LOCK(dsrc);
            popBuffer = (GstBuffer*)g_queue_pop_tail(dataqueue);
            GST_OBJECT_UNLOCK(dsrc);
           
            if(!popBuffer )
//.........这里部分代码省略.........

static GstFlowReturn
gst_identity_transform_ip (GstBaseTransform * trans, GstBuffer * buf)
{
  GstFlowReturn ret = GST_FLOW_OK;
  GstIdentity *identity = GST_IDENTITY (trans);
  GstClockTime runtimestamp = G_GINT64_CONSTANT (0);

  if (identity->check_perfect)
    gst_identity_check_perfect (identity, buf);
  if (identity->check_imperfect_timestamp)
    gst_identity_check_imperfect_timestamp (identity, buf);
  if (identity->check_imperfect_offset)
    gst_identity_check_imperfect_offset (identity, buf);

  /* update prev values */
  identity->prev_timestamp = GST_BUFFER_TIMESTAMP (buf);
  identity->prev_duration = GST_BUFFER_DURATION (buf);
  identity->prev_offset_end = GST_BUFFER_OFFSET_END (buf);
  identity->prev_offset = GST_BUFFER_OFFSET (buf);

  if (identity->error_after >= 0) {
    identity->error_after--;
    if (identity->error_after == 0) {
      GST_ELEMENT_ERROR (identity, CORE, FAILED,
          (_("Failed after iterations as requested.")), (NULL));
      return GST_FLOW_ERROR;
    }
  }

  if (identity->drop_probability > 0.0) {
    if ((gfloat) (1.0 * rand () / (RAND_MAX)) < identity->drop_probability) {
      if (!identity->silent) {
        GST_OBJECT_LOCK (identity);
        g_free (identity->last_message);
        identity->last_message =
            g_strdup_printf
            ("dropping   ******* (%s:%s)i (%d bytes, timestamp: %"
            GST_TIME_FORMAT ", duration: %" GST_TIME_FORMAT ", offset: %"
            G_GINT64_FORMAT ", offset_end: % " G_GINT64_FORMAT
            ", flags: %d) %p", GST_DEBUG_PAD_NAME (trans->sinkpad),
            GST_BUFFER_SIZE (buf), GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)),
            GST_TIME_ARGS (GST_BUFFER_DURATION (buf)), GST_BUFFER_OFFSET (buf),
            GST_BUFFER_OFFSET_END (buf), GST_BUFFER_FLAGS (buf), buf);
        GST_OBJECT_UNLOCK (identity);
        gst_identity_notify_last_message (identity);
      }
      /* return DROPPED to basetransform. */
      return GST_BASE_TRANSFORM_FLOW_DROPPED;
    }
  }

  if (identity->dump) {
    gst_util_dump_mem (GST_BUFFER_DATA (buf), GST_BUFFER_SIZE (buf));
  }

  if (!identity->silent) {
    GST_OBJECT_LOCK (identity);
    g_free (identity->last_message);
    identity->last_message =
        g_strdup_printf ("chain   ******* (%s:%s)i (%d bytes, timestamp: %"
        GST_TIME_FORMAT ", duration: %" GST_TIME_FORMAT ", offset: %"
        G_GINT64_FORMAT ", offset_end: % " G_GINT64_FORMAT ", flags: %d) %p",
        GST_DEBUG_PAD_NAME (trans->sinkpad), GST_BUFFER_SIZE (buf),
        GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)),
        GST_TIME_ARGS (GST_BUFFER_DURATION (buf)),
        GST_BUFFER_OFFSET (buf), GST_BUFFER_OFFSET_END (buf),
        GST_BUFFER_FLAGS (buf), buf);
    GST_OBJECT_UNLOCK (identity);
    gst_identity_notify_last_message (identity);
  }

  if (identity->datarate > 0) {
    GstClockTime time = gst_util_uint64_scale_int (identity->offset,
        GST_SECOND, identity->datarate);

    GST_BUFFER_TIMESTAMP (buf) = time;
    GST_BUFFER_DURATION (buf) =
        GST_BUFFER_SIZE (buf) * GST_SECOND / identity->datarate;
  }

  if (identity->signal_handoffs)
    g_signal_emit (identity, gst_identity_signals[SIGNAL_HANDOFF], 0, buf);

  if (trans->segment.format == GST_FORMAT_TIME)
    runtimestamp = gst_segment_to_running_time (&trans->segment,
        GST_FORMAT_TIME, GST_BUFFER_TIMESTAMP (buf));

  if ((identity->sync) && (trans->segment.format == GST_FORMAT_TIME)) {
    GstClock *clock;

    GST_OBJECT_LOCK (identity);
    if ((clock = GST_ELEMENT (identity)->clock)) {
      GstClockReturn cret;
      GstClockTime timestamp;

      timestamp = runtimestamp + GST_ELEMENT (identity)->base_time;

      /* save id if we need to unlock */
      /* FIXME: actually unlock this somewhere in the state changes */
      identity->clock_id = gst_clock_new_single_shot_id (clock, timestamp);
//.........这里部分代码省略.........

static GstFlowReturn
gst_slvideo_buffer_alloc (GstBaseSink * bsink, guint64 offset, guint size,
			  GstCaps * caps, GstBuffer ** buf)
{
	gint width, height;
	GstStructure *structure = NULL;
	GstSLVideo *slvideo;
	slvideo = GST_SLVIDEO(bsink);

	// caps == requested caps
	// we can ignore these and reverse-negotiate our preferred dimensions with
	// the peer if we like - we need to do this to obey dynamic resize requests
	// flowing in from the app.
	structure = llgst_caps_get_structure (caps, 0);
	if (!llgst_structure_get_int(structure, "width", &width) ||
	    !llgst_structure_get_int(structure, "height", &height))
	{
		GST_WARNING_OBJECT (slvideo, "no width/height in caps %" GST_PTR_FORMAT, caps);
		return GST_FLOW_NOT_NEGOTIATED;
	}

	GstBuffer *newbuf = llgst_buffer_new();
	bool made_bufferdata_ptr = false;
#define MAXDEPTHHACK 4
	
	GST_OBJECT_LOCK(slvideo);
	if (slvideo->resize_forced_always) // app is giving us a fixed size to work with
	{
		gint slwantwidth, slwantheight;
		slwantwidth = slvideo->resize_try_width;
		slwantheight = slvideo->resize_try_height;
	
		if (slwantwidth != width ||
		    slwantheight != height)
		{
			// don't like requested caps, we will issue our own suggestion - copy
			// the requested caps but substitute our own width and height and see
			// if our peer is happy with that.
		
			GstCaps *desired_caps;
			GstStructure *desired_struct;
			desired_caps = llgst_caps_copy (caps);
			desired_struct = llgst_caps_get_structure (desired_caps, 0);
			
			GValue value = {0};
			g_value_init(&value, G_TYPE_INT);
			g_value_set_int(&value, slwantwidth);
			llgst_structure_set_value (desired_struct, "width", &value);
			g_value_unset(&value);
			g_value_init(&value, G_TYPE_INT);
			g_value_set_int(&value, slwantheight);
			llgst_structure_set_value (desired_struct, "height", &value);
			
			if (llgst_pad_peer_accept_caps (GST_VIDEO_SINK_PAD (slvideo),
							desired_caps))
			{
				// todo: re-use buffers from a pool?
				// todo: set MALLOCDATA to null, set DATA to point straight to shm?
				
				// peer likes our cap suggestion
				DEBUGMSG("peer loves us :)");
				GST_BUFFER_SIZE(newbuf) = slwantwidth * slwantheight * MAXDEPTHHACK;
				GST_BUFFER_MALLOCDATA(newbuf) = (guint8*)g_malloc(GST_BUFFER_SIZE(newbuf));
				GST_BUFFER_DATA(newbuf) = GST_BUFFER_MALLOCDATA(newbuf);
				llgst_buffer_set_caps (GST_BUFFER_CAST(newbuf), desired_caps);

				made_bufferdata_ptr = true;
			} else {
				// peer hates our cap suggestion
				INFOMSG("peer hates us :(");
				llgst_caps_unref(desired_caps);
			}
		}
	}

	GST_OBJECT_UNLOCK(slvideo);

	if (!made_bufferdata_ptr) // need to fallback to malloc at original size
	{
		GST_BUFFER_SIZE(newbuf) = width * height * MAXDEPTHHACK;
		GST_BUFFER_MALLOCDATA(newbuf) = (guint8*)g_malloc(GST_BUFFER_SIZE(newbuf));
		GST_BUFFER_DATA(newbuf) = GST_BUFFER_MALLOCDATA(newbuf);
		llgst_buffer_set_caps (GST_BUFFER_CAST(newbuf), caps);
	}

	*buf = GST_BUFFER_CAST(newbuf);

	return GST_FLOW_OK;
}

static GstFlowReturn
gst_amrwbenc_chain (GstPad * pad, GstBuffer * buffer)
{
  GstAmrwbEnc *amrwbenc;
  GstFlowReturn ret = GST_FLOW_OK;
  const int buffer_size = sizeof (Word16) * L_FRAME16k;

  amrwbenc = GST_AMRWBENC (gst_pad_get_parent (pad));

  g_return_val_if_fail (amrwbenc->handle, GST_FLOW_WRONG_STATE);

  if (amrwbenc->rate == 0 || amrwbenc->channels == 0) {
    ret = GST_FLOW_NOT_NEGOTIATED;
    goto done;
  }

  /* discontinuity clears adapter, FIXME, maybe we can set some
   * encoder flag to mask the discont. */
  if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT)) {
    gst_adapter_clear (amrwbenc->adapter);
    amrwbenc->ts = 0;
    amrwbenc->discont = TRUE;
  }

  if (GST_BUFFER_TIMESTAMP_IS_VALID (buffer))
    amrwbenc->ts = GST_BUFFER_TIMESTAMP (buffer);

  ret = GST_FLOW_OK;
  gst_adapter_push (amrwbenc->adapter, buffer);

  /* Collect samples until we have enough for an output frame */
  while (gst_adapter_available (amrwbenc->adapter) >= buffer_size) {
    GstBuffer *out;
    guint8 *data;
    gint outsize;

    out = gst_buffer_new_and_alloc (buffer_size);
    GST_BUFFER_DURATION (out) = GST_SECOND * L_FRAME16k /
        (amrwbenc->rate * amrwbenc->channels);
    GST_BUFFER_TIMESTAMP (out) = amrwbenc->ts;
    if (amrwbenc->ts != -1) {
      amrwbenc->ts += GST_BUFFER_DURATION (out);
    }
    if (amrwbenc->discont) {
      GST_BUFFER_FLAG_SET (out, GST_BUFFER_FLAG_DISCONT);
      amrwbenc->discont = FALSE;
    }
    gst_buffer_set_caps (out, gst_pad_get_caps (amrwbenc->srcpad));

    data = (guint8 *) gst_adapter_peek (amrwbenc->adapter, buffer_size);

    /* encode */
    outsize =
        E_IF_encode (amrwbenc->handle, amrwbenc->bandmode, (Word16 *) data,
        (UWord8 *) GST_BUFFER_DATA (out), 0);

    gst_adapter_flush (amrwbenc->adapter, buffer_size);
    GST_BUFFER_SIZE (out) = outsize;

    /* play */
    if ((ret = gst_pad_push (amrwbenc->srcpad, out)) != GST_FLOW_OK)
      break;
  }

done:

  gst_object_unref (amrwbenc);
  return ret;

}

static GstTagDemuxResult
gst_ape_demux_parse_tag (GstTagDemux * demux, GstBuffer * buffer,
    gboolean start_tag, guint * tag_size, GstTagList ** tags)
{
  const guint8 *data;
  const guint8 *footer;
  gboolean have_header;
  gboolean end_tag = !start_tag;
  GstCaps *sink_caps;
  guint version, footer_size;

  GST_LOG_OBJECT (demux, "Parsing buffer of size %u", GST_BUFFER_SIZE (buffer));

  data = GST_BUFFER_DATA (buffer);
  footer = GST_BUFFER_DATA (buffer) + GST_BUFFER_SIZE (buffer) - 32;

  GST_LOG_OBJECT (demux, "Checking for footer at offset 0x%04x",
      (guint) (footer - data));
  if (footer > data && memcmp (footer, "APETAGEX", 8) == 0) {
    GST_DEBUG_OBJECT (demux, "Found footer");
    footer_size = 32;
  } else {
    GST_DEBUG_OBJECT (demux, "No footer");
    footer_size = 0;
  }

  /* APE tags at the end must have a footer */
  if (end_tag && footer_size == 0) {
    GST_WARNING_OBJECT (demux, "Tag at end of file without footer!");
    return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
  }

  /* don't trust the header/footer flags, better detect them ourselves */
  have_header = (memcmp (data, "APETAGEX", 8) == 0);

  if (start_tag && !have_header) {
    GST_DEBUG_OBJECT (demux, "Tag at beginning of file without header!");
    return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
  }

  if (end_tag && !have_header) {
    GST_DEBUG_OBJECT (demux, "Tag at end of file has no header (APEv1)");
    *tag_size -= 32;            /* adjust tag size */
  }

  if (have_header) {
    version = GST_READ_UINT32_LE (data + 8);
  } else {
    version = GST_READ_UINT32_LE (footer + 8);
  }

  /* skip header */
  if (have_header) {
    data += 32;
  }

  GST_DEBUG_OBJECT (demux, "APE tag with version %u, size %u at offset 0x%08"
      G_GINT64_MODIFIER "x", version, *tag_size,
      GST_BUFFER_OFFSET (buffer) + ((have_header) ? 0 : 32));

  if (APE_VERSION_MAJOR (version) != 1 && APE_VERSION_MAJOR (version) != 2) {
    GST_WARNING ("APE tag is version %u.%03u, but decoder only supports "
        "v1 or v2. Ignoring.", APE_VERSION_MAJOR (version), version % 1000);
    return GST_TAG_DEMUX_RESULT_OK;
  }

  *tags = ape_demux_parse_tags (data, *tag_size - footer_size);

  sink_caps = gst_static_pad_template_get_caps (&sink_factory);
  gst_pb_utils_add_codec_description_to_tag_list (*tags,
      GST_TAG_CONTAINER_FORMAT, sink_caps);
  gst_caps_unref (sink_caps);

  return GST_TAG_DEMUX_RESULT_OK;
}

static GstFlowReturn
gst_base_rtp_audio_payload_push_buffer (GstBaseRTPAudioPayload *
    baseaudiopayload, GstBuffer * buffer)
{
  GstBaseRTPPayload *basepayload;
  GstBaseRTPAudioPayloadPrivate *priv;
  GstBuffer *outbuf;
  GstClockTime timestamp;
  guint8 *payload;
  guint payload_len;
  GstFlowReturn ret;

  priv = baseaudiopayload->priv;
  basepayload = GST_BASE_RTP_PAYLOAD (baseaudiopayload);

  payload_len = GST_BUFFER_SIZE (buffer);
  timestamp = GST_BUFFER_TIMESTAMP (buffer);

  GST_DEBUG_OBJECT (baseaudiopayload, "Pushing %d bytes ts %" GST_TIME_FORMAT,
      payload_len, GST_TIME_ARGS (timestamp));

  if (priv->buffer_list) {
    /* create just the RTP header buffer */
    outbuf = gst_rtp_buffer_new_allocate (0, 0, 0);
  } else {
    /* create buffer to hold the payload */
    outbuf = gst_rtp_buffer_new_allocate (payload_len, 0, 0);
  }

  /* set metadata */
  gst_base_rtp_audio_payload_set_meta (baseaudiopayload, outbuf, payload_len,
      timestamp);

  if (priv->buffer_list) {
    GstBufferList *list;
    GstBufferListIterator *it;

    list = gst_buffer_list_new ();
    it = gst_buffer_list_iterate (list);

    /* add both buffers to the buffer list */
    gst_buffer_list_iterator_add_group (it);
    gst_buffer_list_iterator_add (it, outbuf);
    gst_buffer_list_iterator_add (it, buffer);

    gst_buffer_list_iterator_free (it);

    GST_DEBUG_OBJECT (baseaudiopayload, "Pushing list %p", list);
    ret = gst_basertppayload_push_list (basepayload, list);
  } else {
    /* copy payload */
    payload = gst_rtp_buffer_get_payload (outbuf);
    memcpy (payload, GST_BUFFER_DATA (buffer), payload_len);
    gst_buffer_unref (buffer);

    GST_DEBUG_OBJECT (baseaudiopayload, "Pushing buffer %p", outbuf);
    ret = gst_basertppayload_push (basepayload, outbuf);
  }

  return ret;
}

static GstFlowReturn gst_pgmdec_chain (GstPad * pad, GstBuffer * in)
{
	GstFlowReturn ret = GST_FLOW_OK;
	GstBuffer *out;
	Gstpgmdec *filter = GST_PGMDEC (GST_OBJECT_PARENT (pad));
	//GstCaps *caps = GST_PAD_CAPS (filter->srcpad);
	GstCaps *caps;
	guint byts=0;
	gchar line[4][20];
	//const gchar *l;
	gint  i;
	//GstStructure *structure = gst_caps_get_structure (caps, 0);

	guint8 *outbuf;
	guint8 *inbuf;

	//Get pgm header
	if(!GST_BUFFER_OFFSET(in)){
		//filter->buff = in;
		inbuf = (guint8 *) GST_BUFFER_DATA (in);
		byts = sscanf(inbuf, "%s%s%s%s", line[0], line[1], line[2], line[3]);
		if (strcmp(line[0], "P5") != 0) {
			GST_WARNING ("It's not PGM file");
			return FALSE;
		}
		filter->width = atoi(line[1]);
		filter->height = atoi(line[2]);
		filter->bpp = (atoi(line[3]) > 256) ? 16 : 8;
		for(i=0; i<4; i++) byts += strlen(line[i]);
		filter->size = (filter->bpp == 8) ? filter->width*filter->height : filter->width*filter->height*2;

		//gst_buffer_set_data(filter->buff, &inbuf[byts], GST_BUFFER_SIZE(in)-byts);
		//filter->buff = &inbuf[byts];

		GST_DEBUG_OBJECT (filter, "The file type is : %s width = %d height = %d bpp = %d",
				line[0], filter->width, filter->height, filter->bpp);
		GST_DEBUG_OBJECT (filter, "DATA = %p SIZE = %d OFFSET = %d",
				GST_BUFFER_DATA(in), GST_BUFFER_SIZE(in), GST_BUFFER_OFFSET(in));

		filter->buff = gst_buffer_new_and_alloc(filter->size);
		for(i=0;i < GST_BUFFER_SIZE(in)-byts; i++) GST_BUFFER_DATA(filter->buff)[i] = GST_BUFFER_DATA(in)[byts+i];
		GST_BUFFER_OFFSET(filter->buff) = GST_BUFFER_SIZE(in)-byts;
		gst_buffer_unref(in);

		return GST_FLOW_OK;

		//gst_event_new_seek (1.0,
		//      GST_FORMAT_BYTES,
		//      GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_SEGMENT |GST_SEEK_FLAG_ACCURATE,
		//      GST_SEEK_TYPE_SET, byts,
		//      GST_SEEK_TYPE_SET, filter->size + byts);

	}

	//Check for the buffer size
	if(GST_BUFFER_OFFSET(filter->buff) < GST_BUFFER_SIZE(filter->buff)) {
		for(i=0; i < GST_BUFFER_SIZE(in); i++) GST_BUFFER_DATA(filter->buff)[GST_BUFFER_OFFSET(filter->buff) + i] = GST_BUFFER_DATA(in)[i];
		GST_BUFFER_OFFSET(filter->buff) += GST_BUFFER_SIZE(in);
		//GST_DEBUG_OBJECT (filter, "DATA = %p SIZE = %d OFFSET = %d",GST_BUFFER_DATA(filter->buff), GST_BUFFER_SIZE(filter->buff),GST_BUFFER_OFFSET(filter->buff));
		gst_buffer_unref(in);
		if(GST_BUFFER_OFFSET(filter->buff) != GST_BUFFER_SIZE(filter->buff)) return GST_FLOW_OK;
	}

	GST_DEBUG_OBJECT (filter, "DATA = %p SIZE = %d OFFSET = %d",
				GST_BUFFER_DATA(filter->buff), GST_BUFFER_SIZE(filter->buff), GST_BUFFER_OFFSET(filter->buff));

	caps = gst_caps_new_simple ("video/x-raw-bayer",
								"width", G_TYPE_INT, filter->width,
								"height", G_TYPE_INT, filter->height,
								"bpp", G_TYPE_INT, filter->bpp,
								"framerate", GST_TYPE_FRACTION, 0, 1,
								NULL);
	gst_buffer_set_caps(filter->buff, caps);
	gst_pad_set_caps (filter->srcpad, caps);
	gst_pad_use_fixed_caps (filter->srcpad);
	gst_caps_unref (caps);

  /* just push out the incoming buffer without touching it */
	ret = gst_pad_push(filter->srcpad, filter->buff);
	return ret;
}

static gboolean
start_play_tune (GstNsfDec * nsfdec)
{
  gboolean res;

  nsfdec->nsf = nsf_load (NULL, GST_BUFFER_DATA (nsfdec->tune_buffer),
      GST_BUFFER_SIZE (nsfdec->tune_buffer));

  if (!nsfdec->nsf)
    goto could_not_load;

  if (!nsfdec_negotiate (nsfdec))
    goto could_not_negotiate;

  nsfdec->taglist = gst_tag_list_new ();
  gst_tag_list_add (nsfdec->taglist, GST_TAG_MERGE_REPLACE,
      GST_TAG_AUDIO_CODEC, "NES Sound Format", NULL);

  if (nsfdec->nsf->artist_name)
    gst_tag_list_add (nsfdec->taglist, GST_TAG_MERGE_REPLACE,
        GST_TAG_ARTIST, nsfdec->nsf->artist_name, NULL);

  if (nsfdec->nsf->song_name)
    gst_tag_list_add (nsfdec->taglist, GST_TAG_MERGE_REPLACE,
        GST_TAG_TITLE, nsfdec->nsf->song_name, NULL);

  gst_element_post_message (GST_ELEMENT_CAST (nsfdec),
      gst_message_new_tag (GST_OBJECT (nsfdec),
          gst_tag_list_copy (nsfdec->taglist)));

  nsf_playtrack (nsfdec->nsf,
      nsfdec->tune_number, nsfdec->frequency, nsfdec->bits, nsfdec->stereo);
  nsf_setfilter (nsfdec->nsf, nsfdec->filter);

  nsfdec->bps = (nsfdec->bits >> 3) * nsfdec->channels;
  /* calculate the number of bytes we need to output after each call to
   * nsf_frame(). */
  nsfdec->blocksize =
      nsfdec->bps * nsfdec->frequency / nsfdec->nsf->playback_rate;

  gst_pad_push_event (nsfdec->srcpad,
      gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_TIME, 0, -1, 0));

  res = gst_pad_start_task (nsfdec->srcpad,
      (GstTaskFunction) play_loop, nsfdec->srcpad, NULL);

  return res;

  /* ERRORS */
could_not_load:
  {
    GST_ELEMENT_ERROR (nsfdec, LIBRARY, INIT,
        ("Could not load tune"), ("Could not load tune"));
    return FALSE;
  }
could_not_negotiate:
  {
    GST_ELEMENT_ERROR (nsfdec, CORE, NEGOTIATION,
        ("Could not negotiate format"), ("Could not negotiate format"));
    return FALSE;
  }
}

static GstV4l2Buffer *
gst_v4l2_buffer_new (GstV4l2BufferPool * pool, guint index, GstCaps * caps)
{
  GstV4l2Buffer *ret;
  guint8 *data;

  ret = (GstV4l2Buffer *) gst_mini_object_new (GST_TYPE_V4L2_BUFFER);

  GST_LOG_OBJECT (pool->v4l2elem, "creating buffer %u, %p in pool %p", index,
      ret, pool);

  ret->pool =
      (GstV4l2BufferPool *) gst_mini_object_ref (GST_MINI_OBJECT (pool));

  ret->vbuffer.index = index;
  ret->vbuffer.type = pool->type;
  ret->vbuffer.memory = V4L2_MEMORY_MMAP;

  if (v4l2_ioctl (pool->video_fd, VIDIOC_QUERYBUF, &ret->vbuffer) < 0)
    goto querybuf_failed;

  GST_LOG_OBJECT (pool->v4l2elem, "  index:     %u", ret->vbuffer.index);
  GST_LOG_OBJECT (pool->v4l2elem, "  type:      %d", ret->vbuffer.type);
  GST_LOG_OBJECT (pool->v4l2elem, "  bytesused: %u", ret->vbuffer.bytesused);
  GST_LOG_OBJECT (pool->v4l2elem, "  flags:     %08x", ret->vbuffer.flags);
  GST_LOG_OBJECT (pool->v4l2elem, "  field:     %d", ret->vbuffer.field);
  GST_LOG_OBJECT (pool->v4l2elem, "  memory:    %d", ret->vbuffer.memory);
  if (ret->vbuffer.memory == V4L2_MEMORY_MMAP)
    GST_LOG_OBJECT (pool->v4l2elem, "  MMAP offset:  %u",
        ret->vbuffer.m.offset);
  GST_LOG_OBJECT (pool->v4l2elem, "  length:    %u", ret->vbuffer.length);
  //GST_LOG_OBJECT (pool->v4l2elem, "  input:     %u", ret->vbuffer.input);

  data = (guint8 *) v4l2_mmap (0, ret->vbuffer.length,
      PROT_READ | PROT_WRITE, MAP_SHARED, pool->video_fd,
      ret->vbuffer.m.offset);

  if (data == MAP_FAILED)
    goto mmap_failed;

  GST_BUFFER_DATA (ret) = data;
  GST_BUFFER_SIZE (ret) = ret->vbuffer.length;

  GST_BUFFER_FLAG_SET (ret, GST_BUFFER_FLAG_READONLY);

  gst_buffer_set_caps (GST_BUFFER (ret), caps);

  return ret;

  /* ERRORS */
querybuf_failed:
  {
    gint errnosave = errno;

    GST_WARNING ("Failed QUERYBUF: %s", g_strerror (errnosave));
    gst_buffer_unref (GST_BUFFER (ret));
    errno = errnosave;
    return NULL;
  }
mmap_failed:
  {
    gint errnosave = errno;

    GST_WARNING ("Failed to mmap: %s", g_strerror (errnosave));
    gst_buffer_unref (GST_BUFFER (ret));
    errno = errnosave;
    return NULL;
  }
}