gstreamer/gst/videoscale/gstvideoscale.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */


#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstvideoscale.h"
#include <gst/video/video.h>

#include <string.h>

#include "vs_image.h"

/* debug variable definition */
GST_DEBUG_CATEGORY (videoscale_debug);

/* elementfactory information */
static GstElementDetails videoscale_details =
GST_ELEMENT_DETAILS ("Video scaler",
    "Filter/Effect/Video",
    "Resizes video",
    "Wim Taymans <wim.taymans@chello.be>");

/* GstVideoscale signals and args */
enum
{
  /* FILL ME */
  LAST_SIGNAL
};

enum
{
  ARG_0,
  ARG_METHOD
      /* FILL ME */
};

static GstStaticCaps gst_videoscale_format_caps[] = {
  GST_STATIC_CAPS (GST_VIDEO_CAPS_RGBx),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_xRGB),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_BGRx),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_xBGR),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_RGB),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_BGR),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV")),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("YUY2")),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("YVYU")),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("UYVY")),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("Y800")),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420")),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("YV12")),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_RGB_16),
  GST_STATIC_CAPS (GST_VIDEO_CAPS_RGB_15)
};

enum
{
  GST_VIDEOSCALE_RGBx = 0,
  GST_VIDEOSCALE_xRGB,
  GST_VIDEOSCALE_BGRx,
  GST_VIDEOSCALE_xBGR,
  GST_VIDEOSCALE_RGB,
  GST_VIDEOSCALE_BGR,
  GST_VIDEOSCALE_AYUV,
  GST_VIDEOSCALE_YUY2,
  GST_VIDEOSCALE_YVYU,
  GST_VIDEOSCALE_UYVY,
  GST_VIDEOSCALE_Y,
  GST_VIDEOSCALE_I420,
  GST_VIDEOSCALE_YV12,
  GST_VIDEOSCALE_RGB565,
  GST_VIDEOSCALE_RGB555
};

#define GST_TYPE_VIDEOSCALE_METHOD (gst_videoscale_method_get_type())
static GType
gst_videoscale_method_get_type (void)
{
  static GType videoscale_method_type = 0;
  static GEnumValue videoscale_methods[] = {
    {GST_VIDEOSCALE_POINT_SAMPLE, "0", "Point Sample (not implemented)"},
    {GST_VIDEOSCALE_NEAREST, "1", "Nearest"},
    {GST_VIDEOSCALE_BILINEAR, "2", "Bilinear (not implemented)"},
    {GST_VIDEOSCALE_BICUBIC, "3", "Bicubic (not implemented)"},
    {0, NULL, NULL},
  };

  if (!videoscale_method_type) {
    videoscale_method_type =
        g_enum_register_static ("GstVideoscaleMethod", videoscale_methods);
  }
  return videoscale_method_type;
}

static GstCaps *
gst_videoscale_get_capslist (void)
{
  static GstCaps *caps;

  if (caps == NULL) {
    int i;

    caps = gst_caps_new_empty ();
    for (i = 0; i < G_N_ELEMENTS (gst_videoscale_format_caps); i++) {
      gst_caps_append (caps,
          gst_caps_copy (gst_static_caps_get (&gst_videoscale_format_caps[i])));
    }
  }

  return gst_caps_copy (caps);
}

static GstPadTemplate *
gst_videoscale_src_template_factory (void)
{
  return gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
      gst_videoscale_get_capslist ());
}

static GstPadTemplate *
gst_videoscale_sink_template_factory (void)
{
  return gst_pad_template_new ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
      gst_videoscale_get_capslist ());
}

static void gst_videoscale_base_init (gpointer g_class);
static void gst_videoscale_class_init (GstVideoscaleClass * klass);
static void gst_videoscale_init (GstVideoscale * videoscale);
static gboolean gst_videoscale_handle_src_event (GstPad * pad,
    GstEvent * event);

static void gst_videoscale_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_videoscale_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);
static void gst_videoscale_finalize (GObject * object);

static void gst_videoscale_chain (GstPad * pad, GstData * _data);
static GstCaps *gst_videoscale_get_capslist (void);

static GstElementClass *parent_class = NULL;

/*static guint gst_videoscale_signals[LAST_SIGNAL] = { 0 }; */

GType
gst_videoscale_get_type (void)
{
  static GType videoscale_type = 0;

  if (!videoscale_type) {
    static const GTypeInfo videoscale_info = {
      sizeof (GstVideoscaleClass),
      gst_videoscale_base_init,
      NULL,
      (GClassInitFunc) gst_videoscale_class_init,
      NULL,
      NULL,
      sizeof (GstVideoscale),
      0,
      (GInstanceInitFunc) gst_videoscale_init,
    };

    videoscale_type =
        g_type_register_static (GST_TYPE_ELEMENT, "GstVideoscale",
        &videoscale_info, 0);
  }
  return videoscale_type;
}

static void
gst_videoscale_base_init (gpointer g_class)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

  gst_element_class_set_details (element_class, &videoscale_details);

  gst_element_class_add_pad_template (element_class,
      gst_videoscale_sink_template_factory ());
  gst_element_class_add_pad_template (element_class,
      gst_videoscale_src_template_factory ());
}
static void
gst_videoscale_class_init (GstVideoscaleClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass *) klass;

  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_METHOD, g_param_spec_enum ("method", "method", "method", GST_TYPE_VIDEOSCALE_METHOD, 0, G_PARAM_READWRITE));     /* CHECKME! */

  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);

  gobject_class->finalize = gst_videoscale_finalize;
  gobject_class->set_property = gst_videoscale_set_property;
  gobject_class->get_property = gst_videoscale_get_property;

}

static GstCaps *
gst_videoscale_getcaps (GstPad * pad)
{
  GstVideoscale *videoscale;
  GstCaps *caps;
  GstPad *otherpad;
  int i;

  videoscale = GST_VIDEOSCALE (gst_pad_get_parent (pad));

  otherpad = (pad == videoscale->srcpad) ? videoscale->sinkpad :
      videoscale->srcpad;
  caps = gst_pad_get_allowed_caps (otherpad);

  GST_DEBUG_OBJECT (pad, "othercaps of otherpad %s:%s are: %" GST_PTR_FORMAT,
      GST_DEBUG_PAD_NAME (otherpad), caps);

  for (i = 0; i < gst_caps_get_size (caps); i++) {
    GstStructure *structure = gst_caps_get_structure (caps, i);

    gst_structure_set (structure,
        "width", GST_TYPE_INT_RANGE, 16, 4096,
        "height", GST_TYPE_INT_RANGE, 16, 4096, NULL);
    gst_structure_remove_field (structure, "pixel-aspect-ratio");
  }

  GST_DEBUG_OBJECT (pad, "returning caps: %" GST_PTR_FORMAT, caps);
  return caps;
}

static int
gst_videoscale_get_format (const GstCaps * caps)
{
  int i;
  GstCaps *icaps;

  for (i = 0; i < G_N_ELEMENTS (gst_videoscale_format_caps); i++) {
    icaps = gst_caps_intersect (caps,
        gst_static_caps_get (&gst_videoscale_format_caps[i]));
    if (!gst_caps_is_empty (icaps)) {
      gst_caps_free (icaps);
      return i;
    }
    gst_caps_free (icaps);
  }

  return -1;
}

static GstPadLinkReturn
gst_videoscale_link (GstPad * pad, const GstCaps * caps)
{
  GstVideoscale *videoscale;
  GstPadLinkReturn ret;
  GstPad *otherpad;
  GstCaps *othercaps, *newcaps;
  GstStructure *otherstructure, *structure, *newstructure;
  int format;
  int height = 0, width = 0, newwidth, newheight;
  const GValue *par = NULL, *otherpar;

  GST_DEBUG_OBJECT (pad, "_link with caps %" GST_PTR_FORMAT, caps);
  videoscale = GST_VIDEOSCALE (gst_pad_get_parent (pad));

  otherpad = (pad == videoscale->srcpad) ? videoscale->sinkpad :
      videoscale->srcpad;

  structure = gst_caps_get_structure (caps, 0);
  ret = gst_structure_get_int (structure, "width", &width);
  ret &= gst_structure_get_int (structure, "height", &height);
  par = gst_structure_get_value (structure, "pixel-aspect-ratio");

  format = gst_videoscale_get_format (caps);

  if (!ret || format == -1)
    return GST_PAD_LINK_REFUSED;

  GST_DEBUG_OBJECT (videoscale,
      "trying to set caps %" GST_PTR_FORMAT " on pad %s:%s for passthru",
      caps, GST_DEBUG_PAD_NAME (otherpad));

  ret = gst_pad_try_set_caps (otherpad, caps);
  if (GST_PAD_LINK_SUCCESSFUL (ret)) {
    /* cool, we can use passthru */
    GST_DEBUG_OBJECT (videoscale, "passthru works");
    GST_FLAG_SET (videoscale, GST_ELEMENT_WORK_IN_PLACE);

    videoscale->passthru = TRUE;
    newwidth = width;
    newheight = height;

    goto beach;
  }

  GST_FLAG_UNSET (videoscale, GST_ELEMENT_WORK_IN_PLACE);

  /* no passthru, so try to convert */
  GST_DEBUG_OBJECT (videoscale, "no passthru");

  /* copy caps to find which one works for the otherpad */
  newcaps = gst_caps_copy (caps);
  newstructure = gst_caps_get_structure (newcaps, 0);

  /* iterate over other pad's caps, find a nice conversion.
   * For calculations, we only use the first because we
   * (falsely) assume that all caps have the same PAR and
   * size values. */
  othercaps = gst_pad_get_allowed_caps (otherpad);
  otherstructure = gst_caps_get_structure (othercaps, 0);
  otherpar = gst_structure_get_value (otherstructure, "pixel-aspect-ratio");
  if (par && otherpar) {
    gint num, den, onum, oden;
    gboolean keep_h, w_align, h_align, w_inc;

    /* otherpar can be a list */
    if (G_VALUE_TYPE (otherpar) == GST_TYPE_LIST)
      otherpar = gst_value_list_get_value (otherpar, 0);

    num = gst_value_get_fraction_numerator (par);
    den = gst_value_get_fraction_denominator (par);
    onum = gst_value_get_fraction_numerator (otherpar);
    oden = gst_value_get_fraction_denominator (otherpar);
    w_align = (width * num * oden % (den * onum) == 0);
    h_align = (height * den * onum % (num * oden) == 0);
    w_inc = (num * oden > den * onum);

    /* decide whether to change width or height */
    if (w_align && w_inc)
      keep_h = TRUE;
    else if (h_align && !w_inc)
      keep_h = FALSE;
    else if (w_align)
      keep_h = TRUE;
    else if (h_align)
      keep_h = FALSE;
    else
      keep_h = w_inc;

    /* take par into effect */
    if (keep_h) {
      newwidth = width * num / den;
      newheight = height;
    } else {
      newwidth = width;
      newheight = height * den / num;
    }
  } else {
    /* (at least) one has no par, so it should accept the other */
    newwidth = width;
    newheight = height;
  }

  /* size: don't check return values. We honestly don't care. */
  gst_structure_set_value (newstructure, "width",
      gst_structure_get_value (otherstructure, "width"));
  gst_structure_set_value (newstructure, "height",
      gst_structure_get_value (otherstructure, "height"));
  gst_caps_structure_fixate_field_nearest_int (newstructure, "width", newwidth);
  gst_caps_structure_fixate_field_nearest_int (newstructure,
      "height", newheight);
  gst_structure_get_int (newstructure, "width", &newwidth);
  gst_structure_get_int (newstructure, "height", &newheight);

  /* obviously, keep PAR if we got one */
  if (otherpar)
    gst_structure_set_value (newstructure, "pixel-aspect-ratio", otherpar);
  GST_DEBUG_OBJECT (videoscale,
      "trying to set caps %" GST_PTR_FORMAT " on pad %s:%s for non-passthru",
      caps, GST_DEBUG_PAD_NAME (otherpad));

  /* try - bail out if fail */
  ret = gst_pad_try_set_caps (otherpad, newcaps);
  if (GST_PAD_LINK_FAILED (ret))
    return ret;

  videoscale->passthru = FALSE;

beach:
  /* whee, works. Save for use in _chain and get moving. */
  if (pad == videoscale->srcpad) {
    videoscale->to_width = width;
    videoscale->to_height = height;
    videoscale->from_width = newwidth;
    videoscale->from_height = newheight;
  } else {
    videoscale->from_width = width;
    videoscale->from_height = height;
    videoscale->to_width = newwidth;
    videoscale->to_height = newheight;
  }
  videoscale->format = format;

  GST_DEBUG_OBJECT (videoscale, "work completed");

  return GST_PAD_LINK_OK;
}

static GstCaps *
gst_videoscale_src_fixate (GstPad * pad, const GstCaps * caps)
{
  GstVideoscale *videoscale;
  GstCaps *newcaps;
  int i;
  gboolean ret = TRUE;

  videoscale = GST_VIDEOSCALE (gst_pad_get_parent (pad));

  GST_DEBUG_OBJECT (pad, "asked to fixate caps %" GST_PTR_FORMAT, caps);

  /* don't mess with fixation if we don't have a sink pad PAR */
  if (!videoscale->from_par) {
    GST_DEBUG_OBJECT (videoscale, "no PAR to scale from, not fixating");
    return NULL;
  }

  /* for each structure, if it contains a pixel aspect ratio,
   * fix width and height */

  newcaps = gst_caps_copy (caps);
  for (i = 0; i < gst_caps_get_size (newcaps); i++) {
    const GValue *to_par;

    GstStructure *structure = gst_caps_get_structure (newcaps, i);

    to_par = gst_structure_get_value (structure, "pixel-aspect-ratio");
    if (to_par) {
      GValue to_ratio = { 0, }; /* w/h of output video */
      int from_w, from_h, from_par_n, from_par_d, to_par_n, to_par_d;
      int count = 0;

      int w = 0, h = 0;
      int num, den;

      /* if both width and height are already fixed, we can't do anything
       * about it anymore */
      if (gst_structure_get_int (structure, "width", &w))
        ++count;
      if (gst_structure_get_int (structure, "height", &h))
        ++count;
      if (count == 2) {
        GST_DEBUG_OBJECT (videoscale,
            "dimensions already set to %dx%d, not fixating", w, h);
        return NULL;
      }

      from_w = videoscale->from_width;
      from_h = videoscale->from_height;
      from_par_n = gst_value_get_fraction_numerator (videoscale->from_par);
      from_par_d = gst_value_get_fraction_denominator (videoscale->from_par);
      to_par_n = gst_value_get_fraction_numerator (to_par);
      to_par_d = gst_value_get_fraction_denominator (to_par);

      g_value_init (&to_ratio, GST_TYPE_FRACTION);
      gst_value_set_fraction (&to_ratio, from_w * from_par_n * to_par_d,
          from_h * from_par_d * to_par_n);
      num = gst_value_get_fraction_numerator (&to_ratio);
      den = gst_value_get_fraction_denominator (&to_ratio);
      GST_DEBUG_OBJECT (videoscale,
          "scaling input with %dx%d and PAR %d/%d to output PAR %d/%d",
          from_w, from_h, from_par_n, from_par_d, to_par_n, to_par_d);
      GST_DEBUG_OBJECT (videoscale,
          "resulting output should respect ratio of %d/%d", num, den);

      /* now find a width x height that respects this display ratio.
       * prefer those that have one of w/h the same as the incoming video
       * using wd / hd = num / den */

      /* start with same height, because of interlaced video */
      /* check hd / den is an integer scale factor, and scale wd with the PAR */
      if (from_h % den == 0) {
        GST_DEBUG_OBJECT (videoscale, "keeping video height");
        h = from_h;
        w = h * num / den;
      } else if (from_w % num == 0) {
        GST_DEBUG_OBJECT (videoscale, "keeping video width");
        w = from_w;
        h = w * den / num;
      } else {
        GST_DEBUG_OBJECT (videoscale, "approximating but keeping video height");
        h = from_h;
        w = h * num / den;
      }
      GST_DEBUG_OBJECT (videoscale, "scaling to %dx%d", w, h);

      /* now fixate */
      ret &=
          gst_caps_structure_fixate_field_nearest_int (structure, "width", w);
      ret &=
          gst_caps_structure_fixate_field_nearest_int (structure, "height", h);
    }
  }

  if (ret)
    return newcaps;

  gst_caps_free (newcaps);
  return NULL;
}

static void
gst_videoscale_init (GstVideoscale * videoscale)
{
  GST_DEBUG_OBJECT (videoscale, "_init");
  videoscale->sinkpad =
      gst_pad_new_from_template (gst_videoscale_sink_template_factory (),
      "sink");
  gst_element_add_pad (GST_ELEMENT (videoscale), videoscale->sinkpad);
  gst_pad_set_chain_function (videoscale->sinkpad, gst_videoscale_chain);
  gst_pad_set_link_function (videoscale->sinkpad, gst_videoscale_link);
  gst_pad_set_getcaps_function (videoscale->sinkpad, gst_videoscale_getcaps);

  videoscale->srcpad =
      gst_pad_new_from_template (gst_videoscale_src_template_factory (), "src");
  gst_element_add_pad (GST_ELEMENT (videoscale), videoscale->srcpad);
  gst_pad_set_event_function (videoscale->srcpad,
      gst_videoscale_handle_src_event);
  gst_pad_set_link_function (videoscale->srcpad, gst_videoscale_link);
  gst_pad_set_getcaps_function (videoscale->srcpad, gst_videoscale_getcaps);
  gst_pad_set_fixate_function (videoscale->srcpad, gst_videoscale_src_fixate);

  videoscale->method = GST_VIDEOSCALE_NEAREST;
  /*videoscale->method = GST_VIDEOSCALE_BILINEAR; */
  /*videoscale->method = GST_VIDEOSCALE_POINT_SAMPLE; */
}

static gboolean
gst_videoscale_handle_src_event (GstPad * pad, GstEvent * event)
{
  GstVideoscale *videoscale;
  double a;
  GstStructure *structure;

  videoscale = GST_VIDEOSCALE (gst_pad_get_parent (pad));

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_NAVIGATION:
      event = GST_EVENT (gst_data_copy_on_write (GST_DATA (event)));
      structure = event->event_data.structure.structure;
      if (gst_structure_get_double (structure, "pointer_x", &a)) {
        gst_structure_set (structure, "pointer_x", G_TYPE_DOUBLE,
            a * videoscale->from_width / videoscale->to_width, NULL);
      }
      if (gst_structure_get_double (structure, "pointer_y", &a)) {
        gst_structure_set (structure, "pointer_y", G_TYPE_DOUBLE,
            a * videoscale->from_height / videoscale->to_height, NULL);
      }
      return gst_pad_event_default (pad, event);
      break;
    default:
      GST_DEBUG_OBJECT (videoscale, "passing on non-NAVIGATION event %p",
          event);
      return gst_pad_event_default (pad, event);
      break;
  }
}

#define ROUND_UP_2(x)  (((x)+1)&~1)
#define ROUND_UP_4(x)  (((x)+3)&~3)
#define ROUND_UP_8(x)  (((x)+7)&~7)

static void
gst_videoscale_chain (GstPad * pad, GstData * _data)
{
  GstBuffer *buf = GST_BUFFER (_data);
  GstVideoscale *videoscale;
  gulong size;
  GstBuffer *outbuf;
  VSImage dest;
  VSImage src;
  VSImage dest_u;
  VSImage src_u;
  VSImage dest_v;
  VSImage src_v;
  guint8 *tmpbuf;

  g_return_if_fail (pad != NULL);
  g_return_if_fail (GST_IS_PAD (pad));
  g_return_if_fail (buf != NULL);

  videoscale = GST_VIDEOSCALE (gst_pad_get_parent (pad));

  if (videoscale->passthru) {
    gst_pad_push (videoscale->srcpad, GST_DATA (buf));
    return;
  }

  GST_LOG_OBJECT (videoscale,
      "from=%dx%d to=%dx%d",
      videoscale->from_width, videoscale->from_height,
      videoscale->to_width, videoscale->to_height);

  src.pixels = GST_BUFFER_DATA (buf);
  src.width = videoscale->from_width;
  src.height = videoscale->from_height;

  dest.width = videoscale->to_width;
  dest.height = videoscale->to_height;

  switch (videoscale->format) {
    case GST_VIDEOSCALE_RGBx:
    case GST_VIDEOSCALE_xRGB:
    case GST_VIDEOSCALE_BGRx:
    case GST_VIDEOSCALE_xBGR:
    case GST_VIDEOSCALE_AYUV:
      src.stride = videoscale->from_width * 4;
      dest.stride = videoscale->to_width * 4;
      size = dest.stride * dest.height;
      break;
    case GST_VIDEOSCALE_RGB:
    case GST_VIDEOSCALE_BGR:
      src.stride = ROUND_UP_4 (videoscale->from_width * 3);
      dest.stride = ROUND_UP_4 (videoscale->to_width * 3);
      size = dest.stride * dest.height;
      break;
    case GST_VIDEOSCALE_YUY2:
    case GST_VIDEOSCALE_YVYU:
    case GST_VIDEOSCALE_UYVY:
      src.stride = ROUND_UP_4 (videoscale->from_width * 2);
      dest.stride = ROUND_UP_4 (videoscale->to_width * 2);
      size = dest.stride * dest.height;
      break;
    case GST_VIDEOSCALE_Y:
      src.stride = ROUND_UP_4 (videoscale->from_width);
      dest.stride = ROUND_UP_4 (videoscale->to_width);
      size = dest.stride * dest.height;
      break;
    case GST_VIDEOSCALE_I420:
    case GST_VIDEOSCALE_YV12:
      src.stride = ROUND_UP_4 (videoscale->from_width);
      dest.stride = ROUND_UP_4 (videoscale->to_width);

      src_u.pixels = src.pixels + ROUND_UP_2 (src.height) * src.stride;
      src_u.height = ROUND_UP_2 (src.height) / 2;
      src_u.width = ROUND_UP_2 (src.width) / 2;
      src_u.stride = ROUND_UP_4 (src.stride / 2);

      dest_u.height = ROUND_UP_2 (dest.height) / 2;
      dest_u.width = ROUND_UP_2 (dest.width) / 2;
      dest_u.stride = ROUND_UP_4 (dest.stride / 2);

      memcpy (&src_v, &src_u, sizeof (src_v));
      src_v.pixels = src_u.pixels + src_u.height * src_u.stride;

      memcpy (&dest_v, &dest_u, sizeof (dest_v));

      size = dest.stride * ROUND_UP_2 (dest.height) +
          2 * dest_u.stride * dest_u.height;
      break;
    case GST_VIDEOSCALE_RGB565:
      src.stride = ROUND_UP_4 (videoscale->from_width * 2);
      dest.stride = ROUND_UP_4 (videoscale->to_width * 2);
      size = dest.stride * dest.height;
      break;
    case GST_VIDEOSCALE_RGB555:
      src.stride = ROUND_UP_4 (videoscale->from_width * 2);
      dest.stride = ROUND_UP_4 (videoscale->to_width * 2);
      size = dest.stride * dest.height;
      break;
    default:
      g_warning ("don't know how to scale");
      gst_buffer_unref (buf);
      return;
  }

  outbuf = gst_pad_alloc_buffer (videoscale->srcpad,
      GST_BUFFER_OFFSET_NONE, size);
  gst_buffer_stamp (outbuf, buf);

  dest.pixels = GST_BUFFER_DATA (outbuf);
  switch (videoscale->format) {
    case GST_VIDEOSCALE_I420:
    case GST_VIDEOSCALE_YV12:
      dest_u.pixels = dest.pixels + ROUND_UP_2 (dest.height) * dest.stride;
      dest_v.pixels = dest_u.pixels + dest_u.height * dest_u.stride;
      break;
    default:
      break;
  }

  tmpbuf = g_malloc (dest.stride * 2);

  switch (videoscale->method) {
    case GST_VIDEOSCALE_NEAREST:
      switch (videoscale->format) {
        case GST_VIDEOSCALE_RGBx:
        case GST_VIDEOSCALE_xRGB:
        case GST_VIDEOSCALE_BGRx:
        case GST_VIDEOSCALE_xBGR:
        case GST_VIDEOSCALE_AYUV:
          vs_image_scale_nearest_RGBA (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_RGB:
        case GST_VIDEOSCALE_BGR:
          vs_image_scale_nearest_RGB (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_YUY2:
        case GST_VIDEOSCALE_YVYU:
          vs_image_scale_nearest_YUYV (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_UYVY:
          vs_image_scale_nearest_UYVY (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_Y:
          vs_image_scale_nearest_Y (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_I420:
        case GST_VIDEOSCALE_YV12:
          vs_image_scale_nearest_Y (&dest, &src, tmpbuf);
          vs_image_scale_nearest_Y (&dest_u, &src_u, tmpbuf);
          vs_image_scale_nearest_Y (&dest_v, &src_v, tmpbuf);
          break;
        case GST_VIDEOSCALE_RGB565:
          vs_image_scale_nearest_RGB565 (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_RGB555:
          vs_image_scale_nearest_RGB555 (&dest, &src, tmpbuf);
          break;
        default:
          g_warning ("don't know how to scale");
      }
      break;
    case GST_VIDEOSCALE_BILINEAR:
    case GST_VIDEOSCALE_BICUBIC:
      switch (videoscale->format) {
        case GST_VIDEOSCALE_RGBx:
        case GST_VIDEOSCALE_xRGB:
        case GST_VIDEOSCALE_BGRx:
        case GST_VIDEOSCALE_xBGR:
        case GST_VIDEOSCALE_AYUV:
          vs_image_scale_linear_RGBA (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_RGB:
        case GST_VIDEOSCALE_BGR:
          vs_image_scale_linear_RGB (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_YUY2:
        case GST_VIDEOSCALE_YVYU:
          vs_image_scale_linear_YUYV (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_UYVY:
          vs_image_scale_linear_UYVY (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_Y:
          vs_image_scale_linear_Y (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_I420:
        case GST_VIDEOSCALE_YV12:
          vs_image_scale_linear_Y (&dest, &src, tmpbuf);
          //memset (dest_u.pixels, 128, dest_u.stride * dest_u.height);
          //memset (dest_v.pixels, 128, dest_v.stride * dest_v.height);
          vs_image_scale_linear_Y (&dest_u, &src_u, tmpbuf);
          vs_image_scale_linear_Y (&dest_v, &src_v, tmpbuf);
          break;
        case GST_VIDEOSCALE_RGB565:
          vs_image_scale_linear_RGB565 (&dest, &src, tmpbuf);
          break;
        case GST_VIDEOSCALE_RGB555:
          vs_image_scale_linear_RGB555 (&dest, &src, tmpbuf);
          break;
        default:
          g_warning ("don't know how to scale");
      }
      break;
    default:
      g_assert_not_reached ();
      break;
  }

  g_free (tmpbuf);

  GST_LOG_OBJECT (videoscale, "pushing buffer of %d bytes",
      GST_BUFFER_SIZE (outbuf));

  gst_pad_push (videoscale->srcpad, GST_DATA (outbuf));

  gst_buffer_unref (buf);
}

static void
gst_videoscale_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstVideoscale *src;

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail (GST_IS_VIDEOSCALE (object));
  src = GST_VIDEOSCALE (object);

  GST_DEBUG_OBJECT (src, "gst_videoscale_set_property");
  switch (prop_id) {
    case ARG_METHOD:
      src->method = g_value_get_enum (value);
      break;
    default:
      break;
  }
}

static void
gst_videoscale_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstVideoscale *src;

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail (GST_IS_VIDEOSCALE (object));
  src = GST_VIDEOSCALE (object);

  switch (prop_id) {
    case ARG_METHOD:
      g_value_set_enum (value, src->method);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

/* maybe these free's should go in a state change instead;
 * in that case, we'd probably also want to clear from/to width/height there. */
static void
gst_videoscale_finalize (GObject * object)
{
  GstVideoscale *videoscale;

  videoscale = GST_VIDEOSCALE (object);

  g_free (videoscale->from_par);
  g_free (videoscale->to_par);

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  if (!gst_element_register (plugin, "videoscale", GST_RANK_NONE,
          GST_TYPE_VIDEOSCALE))
    return FALSE;

  GST_DEBUG_CATEGORY_INIT (videoscale_debug, "videoscale", 0,
      "videoscale element");

  return TRUE;
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    "videoscale",
    "Resizes video", plugin_init, VERSION, GST_LICENSE, GST_PACKAGE, GST_ORIGIN)