gstreamer/gst-libs/gst/idct/idct.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 <gst/gst.h>
#include <gst/idct/idct.h>
#include "dct.h"

static void gst_idct_int_sparse_idct (short *data);

GstIDCT *
gst_idct_new (GstIDCTMethod method)
{
  GstIDCT *new = g_malloc (sizeof (GstIDCT));

  new->need_transpose = FALSE;

  if (method == GST_IDCT_DEFAULT) {
    method = GST_IDCT_FAST_INT;
  }

  new->convert_sparse = gst_idct_int_sparse_idct;

  switch (method) {
    case GST_IDCT_FAST_INT:
      GST_INFO ("using fast_int_idct");
      gst_idct_init_fast_int_idct ();
      new->convert = gst_idct_fast_int_idct;
      break;
    case GST_IDCT_INT:
      GST_INFO ("using int_idct");
      new->convert = gst_idct_int_idct;
      break;
    case GST_IDCT_FLOAT:
      GST_INFO ("using float_idct");
      gst_idct_init_float_idct ();
      new->convert = gst_idct_float_idct;
      break;
    default:
      GST_INFO ("method not supported");
      g_free (new);
      return NULL;
  }
  return new;
}

static void
gst_idct_int_sparse_idct (short *data)
{
  short val;
  gint32 v, *dp = (guint32 *) data;

  v = *data;

  if (v < 0) {
    val = -v;
    val += (8 >> 1);
    val /= 8;
    val = -val;
  } else {
    val = (v + (8 >> 1)) / 8;
  }
  v = ((val & 0xffff) | (val << 16));

  dp[0] = v;
  dp[1] = v;
  dp[2] = v;
  dp[3] = v;
  dp[4] = v;
  dp[5] = v;
  dp[6] = v;
  dp[7] = v;
  dp[8] = v;
  dp[9] = v;
  dp[10] = v;
  dp[11] = v;
  dp[12] = v;
  dp[13] = v;
  dp[14] = v;
  dp[15] = v;
  dp[16] = v;
  dp[17] = v;
  dp[18] = v;
  dp[19] = v;
  dp[20] = v;
  dp[21] = v;
  dp[22] = v;
  dp[23] = v;
  dp[24] = v;
  dp[25] = v;
  dp[26] = v;
  dp[27] = v;
  dp[28] = v;
  dp[29] = v;
  dp[30] = v;
  dp[31] = v;
}

void
gst_idct_destroy (GstIDCT * idct)
{
  g_return_if_fail (idct != NULL);

  g_free (idct);
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  return TRUE;
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    "gstidct",
    "Accelerated IDCT routines",
    plugin_init, VERSION, GST_LICENSE, GST_PACKAGE, GST_ORIGIN)