C++ GST_VIDEO_FRAME_PLANE_DATA函数代码示例

static GstFlowReturn
gst_mpeg2dec_alloc_buffer (GstMpeg2dec * mpeg2dec, GstVideoCodecFrame * frame,
    GstBuffer ** buffer)
{
  GstFlowReturn ret;
  GstVideoFrame vframe;
  guint8 *buf[3];

  ret =
      gst_mpeg2dec_alloc_sized_buf (mpeg2dec, mpeg2dec->decoded_info.size,
      frame, buffer);
  if (G_UNLIKELY (ret != GST_FLOW_OK))
    goto beach;

  if (mpeg2dec->need_cropping && mpeg2dec->has_cropping) {
    GstVideoCropMeta *crop;
    GstVideoCodecState *state;
    GstVideoInfo *vinfo;

    state = gst_video_decoder_get_output_state (GST_VIDEO_DECODER (mpeg2dec));
    vinfo = &state->info;

    crop = gst_buffer_add_video_crop_meta (frame->output_buffer);
    /* we can do things slightly more efficient when we know that
     * downstream understands clipping */
    crop->x = 0;
    crop->y = 0;
    crop->width = vinfo->width;
    crop->height = vinfo->height;

    gst_video_codec_state_unref (state);
  }

  if (!gst_video_frame_map (&vframe, &mpeg2dec->decoded_info, *buffer,
          GST_MAP_READ | GST_MAP_WRITE))
    goto map_fail;

  buf[0] = GST_VIDEO_FRAME_PLANE_DATA (&vframe, 0);
  buf[1] = GST_VIDEO_FRAME_PLANE_DATA (&vframe, 1);
  buf[2] = GST_VIDEO_FRAME_PLANE_DATA (&vframe, 2);

  GST_DEBUG_OBJECT (mpeg2dec, "set_buf: %p %p %p, frame %i",
      buf[0], buf[1], buf[2], frame->system_frame_number);

  /* Note: We use a non-null 'id' value to make the distinction
   * between the dummy buffers (which have an id of NULL) and the
   * ones we did */
  mpeg2_set_buf (mpeg2dec->decoder, buf,
      GINT_TO_POINTER (frame->system_frame_number + 1));
  gst_mpeg2dec_save_buffer (mpeg2dec, frame->system_frame_number, &vframe);

beach:
  return ret;

map_fail:
  {
    GST_ERROR_OBJECT (mpeg2dec, "Failed to map frame");
    return GST_FLOW_ERROR;
  }
}

/* this function does the actual processing
 */
static GstFlowReturn
gst_yuv_to_rgb_transform_frame (GstVideoFilter *filter, GstVideoFrame *in_frame, GstVideoFrame *out_frame)
{
  GstYuvToRgb *rgbtoyuv = GST_YUVTORGB_CAST (filter);
  gint width, height, stride;
  gint y_stride, uv_stride;
  guint32 *out_data;
  guint8 *y_in, *u_in, *v_in;

  y_stride = GST_VIDEO_FRAME_PLANE_STRIDE (in_frame, 0);
  uv_stride = GST_VIDEO_FRAME_PLANE_STRIDE (in_frame, 1);

  y_in = (guint8*) GST_VIDEO_FRAME_PLANE_DATA (in_frame, 0);
  u_in = (guint8*) GST_VIDEO_FRAME_PLANE_DATA (in_frame, 1);
  v_in = (guint8*) GST_VIDEO_FRAME_PLANE_DATA (in_frame, 2);

  width = GST_VIDEO_FRAME_WIDTH (out_frame);
  height = GST_VIDEO_FRAME_HEIGHT (out_frame);
  stride = GST_VIDEO_FRAME_PLANE_STRIDE (out_frame, 0);

  out_data = (guint32*) GST_VIDEO_FRAME_PLANE_DATA (out_frame, 0);

  // GST_INFO ("DEBUG_INFO: rgbtoyuv::transform_frame: ");
  // GST_INFO ("in stride: %d; out stride: %d %d\n", stride, y_stride, uv_stride);

  libyuv::I420ToARGB (y_in, y_stride,
              u_in, uv_stride,
              v_in, uv_stride,
              (guint8*)out_data, stride,
              width, height);

  return GST_FLOW_OK;
}

static void
gst_video_crop_transform_packed_simple (GstVideoCrop * vcrop,
    GstVideoFrame * in_frame, GstVideoFrame * out_frame)
{
  guint8 *in_data, *out_data;
  gint width, height;
  guint i, dx;
  gint in_stride, out_stride;

  width = GST_VIDEO_FRAME_WIDTH (out_frame);
  height = GST_VIDEO_FRAME_HEIGHT (out_frame);

  in_data = GST_VIDEO_FRAME_PLANE_DATA (in_frame, 0);
  out_data = GST_VIDEO_FRAME_PLANE_DATA (out_frame, 0);

  in_stride = GST_VIDEO_FRAME_PLANE_STRIDE (in_frame, 0);
  out_stride = GST_VIDEO_FRAME_PLANE_STRIDE (out_frame, 0);

  in_data += vcrop->crop_top * in_stride;
  in_data += vcrop->crop_left * GST_VIDEO_FRAME_COMP_PSTRIDE (in_frame, 0);

  dx = width * GST_VIDEO_FRAME_COMP_PSTRIDE (out_frame, 0);

  for (i = 0; i < height; ++i) {
    memcpy (out_data, in_data, dx);
    in_data += in_stride;
    out_data += out_stride;
  }
}

static void
copy_field (GstInterlace * interlace, GstBuffer * dest, GstBuffer * src,
    int field_index)
{
  GstVideoInfo *info = &interlace->info;
  gint i, j, n_planes;
  guint8 *d, *s;
  GstVideoFrame dframe, sframe;

  if (!gst_video_frame_map (&dframe, info, dest, GST_MAP_WRITE))
    goto dest_map_failed;

  if (!gst_video_frame_map (&sframe, info, src, GST_MAP_READ))
    goto src_map_failed;

  n_planes = GST_VIDEO_FRAME_N_PLANES (&dframe);

  for (i = 0; i < n_planes; i++) {
    gint cheight, cwidth;
    gint ss, ds;

    d = GST_VIDEO_FRAME_PLANE_DATA (&dframe, i);
    s = GST_VIDEO_FRAME_PLANE_DATA (&sframe, i);

    ds = GST_VIDEO_FRAME_PLANE_STRIDE (&dframe, i);
    ss = GST_VIDEO_FRAME_PLANE_STRIDE (&sframe, i);

    d += field_index * ds;
    s += field_index * ss;

    cheight = GST_VIDEO_FRAME_COMP_HEIGHT (&dframe, i);
    cwidth = MIN (ABS (ss), ABS (ds));

    for (j = field_index; j < cheight; j += 2) {
      memcpy (d, s, cwidth);
      d += ds * 2;
      s += ss * 2;
    }
  }

  gst_video_frame_unmap (&dframe);
  gst_video_frame_unmap (&sframe);
  return;

dest_map_failed:
  {
    GST_ERROR_OBJECT (interlace, "failed to map dest");
    return;
  }
src_map_failed:
  {
    GST_ERROR_OBJECT (interlace, "failed to map src");
    gst_video_frame_unmap (&dframe);
    return;
  }
}

static void
gst_video_balance_semiplanar_yuv (GstVideoBalance * videobalance,
    GstVideoFrame * frame)
{
  gint x, y;
  guint8 *ydata;
  guint8 *uvdata;
  gint ystride, uvstride;
  gint width, height;
  gint width2, height2;
  guint8 *tabley = videobalance->tabley;
  guint8 **tableu = videobalance->tableu;
  guint8 **tablev = videobalance->tablev;
  gint upos, vpos;

  width = GST_VIDEO_FRAME_WIDTH (frame);
  height = GST_VIDEO_FRAME_HEIGHT (frame);

  ydata = GST_VIDEO_FRAME_PLANE_DATA (frame, 0);
  ystride = GST_VIDEO_FRAME_PLANE_STRIDE (frame, 0);

  for (y = 0; y < height; y++) {
    guint8 *yptr;

    yptr = ydata + y * ystride;
    for (x = 0; x < width; x++) {
      *yptr = tabley[*yptr];
      yptr++;
    }
  }

  width2 = GST_VIDEO_FRAME_COMP_WIDTH (frame, 1);
  height2 = GST_VIDEO_FRAME_COMP_HEIGHT (frame, 1);

  uvdata = GST_VIDEO_FRAME_PLANE_DATA (frame, 1);
  uvstride = GST_VIDEO_FRAME_PLANE_STRIDE (frame, 1);

  upos = GST_VIDEO_INFO_FORMAT (&frame->info) == GST_VIDEO_FORMAT_NV12 ? 0 : 1;
  vpos = GST_VIDEO_INFO_FORMAT (&frame->info) == GST_VIDEO_FORMAT_NV12 ? 1 : 0;

  for (y = 0; y < height2; y++) {
    guint8 *uvptr;
    guint8 u1, v1;

    uvptr = uvdata + y * uvstride;

    for (x = 0; x < width2; x++) {
      u1 = uvptr[upos];
      v1 = uvptr[vpos];

      uvptr[upos] = tableu[u1][v1];
      uvptr[vpos] = tablev[u1][v1];
      uvptr += 2;
    }
  }
}

static void
gst_video_balance_planar_yuv (GstVideoBalance * videobalance,
    GstVideoFrame * frame)
{
  gint x, y;
  guint8 *ydata;
  guint8 *udata, *vdata;
  gint ystride, ustride, vstride;
  gint width, height;
  gint width2, height2;
  guint8 *tabley = videobalance->tabley;
  guint8 **tableu = videobalance->tableu;
  guint8 **tablev = videobalance->tablev;

  width = GST_VIDEO_FRAME_WIDTH (frame);
  height = GST_VIDEO_FRAME_HEIGHT (frame);

  ydata = GST_VIDEO_FRAME_PLANE_DATA (frame, 0);
  ystride = GST_VIDEO_FRAME_PLANE_STRIDE (frame, 0);

  for (y = 0; y < height; y++) {
    guint8 *yptr;

    yptr = ydata + y * ystride;
    for (x = 0; x < width; x++) {
      *yptr = tabley[*yptr];
      yptr++;
    }
  }

  width2 = GST_VIDEO_FRAME_COMP_WIDTH (frame, 1);
  height2 = GST_VIDEO_FRAME_COMP_HEIGHT (frame, 1);

  udata = GST_VIDEO_FRAME_PLANE_DATA (frame, 1);
  vdata = GST_VIDEO_FRAME_PLANE_DATA (frame, 2);
  ustride = GST_VIDEO_FRAME_PLANE_STRIDE (frame, 1);
  vstride = GST_VIDEO_FRAME_PLANE_STRIDE (frame, 2);

  for (y = 0; y < height2; y++) {
    guint8 *uptr, *vptr;
    guint8 u1, v1;

    uptr = udata + y * ustride;
    vptr = vdata + y * vstride;

    for (x = 0; x < width2; x++) {
      u1 = *uptr;
      v1 = *vptr;

      *uptr++ = tableu[u1][v1];
      *vptr++ = tablev[u1][v1];
    }
  }
}

static void
gst_video_crop_transform_packed_complex (GstVideoCrop * vcrop,
    GstVideoFrame * in_frame, GstVideoFrame * out_frame)
{
  guint8 *in_data, *out_data;
  guint i, dx;
  gint width, height;
  gint in_stride;
  gint out_stride;

  width = GST_VIDEO_FRAME_WIDTH (out_frame);
  height = GST_VIDEO_FRAME_HEIGHT (out_frame);

  in_data = GST_VIDEO_FRAME_PLANE_DATA (in_frame, 0);
  out_data = GST_VIDEO_FRAME_PLANE_DATA (out_frame, 0);

  in_stride = GST_VIDEO_FRAME_PLANE_STRIDE (in_frame, 0);
  out_stride = GST_VIDEO_FRAME_PLANE_STRIDE (out_frame, 0);

  in_data += vcrop->crop_top * in_stride;

  /* rounding down here so we end up at the start of a macro-pixel and not
   * in the middle of one */
  in_data += ROUND_DOWN_2 (vcrop->crop_left) *
      GST_VIDEO_FRAME_COMP_PSTRIDE (in_frame, 0);

  dx = width * GST_VIDEO_FRAME_COMP_PSTRIDE (out_frame, 0);

  /* UYVY = 4:2:2 - [U0 Y0 V0 Y1] [U2 Y2 V2 Y3] [U4 Y4 V4 Y5]
   * YUYV = 4:2:2 - [Y0 U0 Y1 V0] [Y2 U2 Y3 V2] [Y4 U4 Y5 V4] = YUY2 */
  if ((vcrop->crop_left % 2) != 0) {
    for (i = 0; i < height; ++i) {
      gint j;

      memcpy (out_data, in_data, dx);

      /* move just the Y samples one pixel to the left, don't worry about
       * chroma shift */
      for (j = vcrop->macro_y_off; j < out_stride - 2; j += 2)
        out_data[j] = in_data[j + 2];

      in_data += in_stride;
      out_data += out_stride;
    }
  } else {
    for (i = 0; i < height; ++i) {
      memcpy (out_data, in_data, dx);
      in_data += in_stride;
      out_data += out_stride;
    }
  }
}

static GstFlowReturn
gst_shagadelictv_transform_frame (GstVideoFilter * vfilter,
                                  GstVideoFrame * in_frame, GstVideoFrame * out_frame)
{
    GstShagadelicTV *filter = GST_SHAGADELICTV (vfilter);
    guint32 *src, *dest;
    gint x, y;
    guint32 v;
    guint8 r, g, b;
    gint width, height;

    src = GST_VIDEO_FRAME_PLANE_DATA (in_frame, 0);
    dest = GST_VIDEO_FRAME_PLANE_DATA (out_frame, 0);

    width = GST_VIDEO_FRAME_WIDTH (in_frame);
    height = GST_VIDEO_FRAME_HEIGHT (in_frame);

    for (y = 0; y < height; y++) {
        for (x = 0; x < width; x++) {
            v = *src++ | 0x1010100;
            v = (v - 0x707060) & 0x1010100;
            v -= v >> 8;
            /* Try another Babe!
             * v = *src++;
             * *dest++ = v & ((r<<16)|(g<<8)|b);
             */
            r = ((gint8) (filter->ripple[(filter->ry + y) * width * 2 + filter->rx +
                                         x] + filter->phase * 2)) >> 7;
            g = ((gint8) (filter->spiral[y * width + x] + filter->phase * 3)) >> 7;
            b = ((gint8) (filter->ripple[(filter->by + y) * width * 2 + filter->bx +
                                         x] - filter->phase)) >> 7;
            *dest++ = v & ((r << 16) | (g << 8) | b);
        }
    }

    filter->phase -= 8;
    if ((filter->rx + filter->rvx) < 0 || (filter->rx + filter->rvx) >= width)
        filter->rvx = -filter->rvx;
    if ((filter->ry + filter->rvy) < 0 || (filter->ry + filter->rvy) >= height)
        filter->rvy = -filter->rvy;
    if ((filter->bx + filter->bvx) < 0 || (filter->bx + filter->bvx) >= width)
        filter->bvx = -filter->bvx;
    if ((filter->by + filter->bvy) < 0 || (filter->by + filter->bvy) >= height)
        filter->bvy = -filter->bvy;
    filter->rx += filter->rvx;
    filter->ry += filter->rvy;
    filter->bx += filter->bvx;
    filter->by += filter->bvy;

    return GST_FLOW_OK;
}

static void
gst_deinterlace_simple_method_deinterlace_frame_planar (GstDeinterlaceMethod *
    method, const GstDeinterlaceField * history, guint history_count,
    GstVideoFrame * outframe, gint cur_field_idx)
{
  GstDeinterlaceSimpleMethod *self = GST_DEINTERLACE_SIMPLE_METHOD (method);
  GstDeinterlaceMethodClass *dm_class = GST_DEINTERLACE_METHOD_GET_CLASS (self);
  guint8 *out;
  const guint8 *field0, *field1, *field2, *fieldp;
  guint cur_field_flags = history[cur_field_idx].flags;
  gint i;
  GstDeinterlaceSimpleMethodFunction copy_scanline;
  GstDeinterlaceSimpleMethodFunction interpolate_scanline;

  g_assert (self->interpolate_scanline_planar[0] != NULL);
  g_assert (self->interpolate_scanline_planar[1] != NULL);
  g_assert (self->interpolate_scanline_planar[2] != NULL);
  g_assert (self->copy_scanline_planar[0] != NULL);
  g_assert (self->copy_scanline_planar[1] != NULL);
  g_assert (self->copy_scanline_planar[2] != NULL);

  for (i = 0; i < 3; i++) {
    copy_scanline = self->copy_scanline_planar[i];
    interpolate_scanline = self->interpolate_scanline_planar[i];

    out = GST_VIDEO_FRAME_PLANE_DATA (outframe, i);

    fieldp = NULL;
    if (cur_field_idx > 0) {
      fieldp = GST_VIDEO_FRAME_PLANE_DATA (history[cur_field_idx - 1].frame, i);
    }

    field0 = GST_VIDEO_FRAME_PLANE_DATA (history[cur_field_idx].frame, i);

    g_assert (dm_class->fields_required <= 4);

    field1 = NULL;
    if (cur_field_idx + 1 < history_count) {
      field1 = GST_VIDEO_FRAME_PLANE_DATA (history[cur_field_idx + 1].frame, i);
    }

    field2 = NULL;
    if (cur_field_idx + 2 < history_count) {
      field2 = GST_VIDEO_FRAME_PLANE_DATA (history[cur_field_idx + 2].frame, i);
    }

    gst_deinterlace_simple_method_deinterlace_frame_planar_plane (self, out,
        field0, field1, field2, fieldp, cur_field_flags, i, copy_scanline,
        interpolate_scanline);
  }
}

/* Copy the frame data from the GstBuffer (from decoder)
 * to the picture obtained from downstream in VLC.
 * This function should be avoided as much
 * as possible, since it involves a complete frame copy. */
static void gst_CopyPicture( picture_t *p_pic, GstVideoFrame *p_frame )
{
    int i_plane, i_planes, i_line, i_dst_stride, i_src_stride;
    uint8_t *p_dst, *p_src;
    int i_w, i_h;

    i_planes = p_pic->i_planes;
    for( i_plane = 0; i_plane < i_planes; i_plane++ )
    {
        p_dst = p_pic->p[i_plane].p_pixels;
        p_src = GST_VIDEO_FRAME_PLANE_DATA( p_frame, i_plane );
        i_dst_stride = p_pic->p[i_plane].i_pitch;
        i_src_stride = GST_VIDEO_FRAME_PLANE_STRIDE( p_frame, i_plane );

        i_w = GST_VIDEO_FRAME_COMP_WIDTH( p_frame,
                i_plane ) * GST_VIDEO_FRAME_COMP_PSTRIDE( p_frame, i_plane );
        i_h = GST_VIDEO_FRAME_COMP_HEIGHT( p_frame, i_plane );

        for( i_line = 0;
                i_line < __MIN( p_pic->p[i_plane].i_lines, i_h );
                i_line++ )
        {
            memcpy( p_dst, p_src, i_w );
            p_src += i_src_stride;
            p_dst += i_dst_stride;
        }
    }
}

static GstFlowReturn
openni2_read_gstbuffer (GstOpenni2Src * src, GstBuffer * buf)
{
  openni::Status rc = openni::STATUS_OK;
  openni::VideoStream * pStream = src->depth;
  int changedStreamDummy;
  GstVideoFrame vframe;
  uint64_t oni_ts;

  /* Block until we get some data */
  rc = openni::OpenNI::waitForAnyStream (&pStream, 1, &changedStreamDummy,
      SAMPLE_READ_WAIT_TIMEOUT);
  if (rc != openni::STATUS_OK) {
    GST_ERROR_OBJECT (src, "Frame read timeout: %s",
        openni::OpenNI::getExtendedError ());
    return GST_FLOW_ERROR;
  }

  if (src->depth->isValid () && src->color->isValid () &&
      src->sourcetype == SOURCETYPE_BOTH) {
    rc = src->depth->readFrame (src->depthFrame);
    if (rc != openni::STATUS_OK) {
      GST_ERROR_OBJECT (src, "Frame read error: %s",
          openni::OpenNI::getExtendedError ());
      return GST_FLOW_ERROR;
    }
    rc = src->color->readFrame (src->colorFrame);
    if (rc != openni::STATUS_OK) {
      GST_ERROR_OBJECT (src, "Frame read error: %s",
          openni::OpenNI::getExtendedError ());
      return GST_FLOW_ERROR;
    }

    /* Copy colour information */
    gst_video_frame_map (&vframe, &src->info, buf, GST_MAP_WRITE);

    guint8 *pData = (guint8 *) GST_VIDEO_FRAME_PLANE_DATA (&vframe, 0);
    guint8 *pColor = (guint8 *) src->colorFrame->getData ();
    /* Add depth as 8bit alpha channel, depth is 16bit samples. */
    guint16 *pDepth = (guint16 *) src->depthFrame->getData ();

    for (int i = 0; i < src->colorFrame->getHeight (); ++i) {
      for (int j = 0; j < src->colorFrame->getWidth (); ++j) {
        pData[4 * j + 0] = pColor[3 * j + 0];
        pData[4 * j + 1] = pColor[3 * j + 1];
        pData[4 * j + 2] = pColor[3 * j + 2];
        pData[4 * j + 3] = pDepth[j] >> 8;
      }
      pData += GST_VIDEO_FRAME_PLANE_STRIDE (&vframe, 0);
      pColor += src->colorFrame->getStrideInBytes ();
      pDepth += src->depthFrame->getStrideInBytes () / 2;
    }
    gst_video_frame_unmap (&vframe);

    oni_ts = src->colorFrame->getTimestamp () * 1000;

    GST_LOG_OBJECT (src, "sending buffer (%d+%d)B",
        src->colorFrame->getDataSize (),
        src->depthFrame->getDataSize ());
  } else if (src->depth->isValid () && src->sourcetype == SOURCETYPE_DEPTH) {

static void
fill_image_packed8_3 (opj_image_t * image, GstVideoFrame * frame)
{
  gint x, y, w, h;
  const guint8 *data_in, *tmp;
  gint *data_out[3];
  gint sstride;

  w = GST_VIDEO_FRAME_WIDTH (frame);
  h = GST_VIDEO_FRAME_HEIGHT (frame);
  data_in = GST_VIDEO_FRAME_PLANE_DATA (frame, 0);
  sstride = GST_VIDEO_FRAME_PLANE_STRIDE (frame, 0);

  data_out[0] = image->comps[0].data;
  data_out[1] = image->comps[1].data;
  data_out[2] = image->comps[2].data;

  for (y = 0; y < h; y++) {
    tmp = data_in;

    for (x = 0; x < w; x++) {
      *data_out[0] = tmp[1];
      *data_out[1] = tmp[2];
      *data_out[2] = tmp[3];

      tmp += 4;
      data_out[0]++;
      data_out[1]++;
      data_out[2]++;
    }
    data_in += sstride;
  }
}

static void
fill_frame_planar16_1 (GstVideoFrame * frame, opj_image_t * image)
{
  gint x, y, w, h;
  guint16 *data_out, *tmp;
  const gint *data_in;
  gint dstride;
  gint shift;

  w = GST_VIDEO_FRAME_WIDTH (frame);
  h = GST_VIDEO_FRAME_HEIGHT (frame);
  data_out = GST_VIDEO_FRAME_PLANE_DATA (frame, 0);
  dstride = GST_VIDEO_FRAME_PLANE_STRIDE (frame, 0) / 2;

  data_in = image->comps[0].data;

  shift = 16 - image->comps[0].prec;

  for (y = 0; y < h; y++) {
    tmp = data_out;

    for (x = 0; x < w; x++) {
      *tmp = *data_in << shift;

      tmp++;
      data_in++;
    }
    data_out += dstride;
  }
}

static void
fill_frame_packed8_3 (GstVideoFrame * frame, opj_image_t * image)
{
  gint x, y, w, h;
  guint8 *data_out, *tmp;
  const gint *data_in[3];
  gint dstride;

  w = GST_VIDEO_FRAME_WIDTH (frame);
  h = GST_VIDEO_FRAME_HEIGHT (frame);
  data_out = GST_VIDEO_FRAME_PLANE_DATA (frame, 0);
  dstride = GST_VIDEO_FRAME_PLANE_STRIDE (frame, 0);

  data_in[0] = image->comps[0].data;
  data_in[1] = image->comps[1].data;
  data_in[2] = image->comps[2].data;

  for (y = 0; y < h; y++) {
    tmp = data_out;

    for (x = 0; x < w; x++) {
      tmp[1] = *data_in[0];
      tmp[2] = *data_in[1];
      tmp[3] = *data_in[2];

      tmp += 4;
      data_in[0]++;
      data_in[1]++;
      data_in[2]++;
    }
    data_out += dstride;
  }
}

static GstFlowReturn
gst_cacasink_render (GstBaseSink * basesink, GstBuffer * buffer)
{
  GstCACASink *cacasink = GST_CACASINK (basesink);
  GstVideoFrame frame;

  GST_DEBUG ("render");

  if (!gst_video_frame_map (&frame, &cacasink->info, buffer, GST_MAP_READ))
    goto invalid_frame;

  caca_clear ();
  caca_draw_bitmap (0, 0, cacasink->screen_width - 1,
      cacasink->screen_height - 1, cacasink->bitmap,
      GST_VIDEO_FRAME_PLANE_DATA (&frame, 0));
  caca_refresh ();

  gst_video_frame_unmap (&frame);

  return GST_FLOW_OK;

  /* ERRORS */
invalid_frame:
  {
    GST_ERROR_OBJECT (cacasink, "invalid frame received");
    return GST_FLOW_ERROR;
  }
}