libswfdec/swfdec_codec_vp6_alpha.c

   1 /* Swfdec
   2  * Copyright (C) 2007 Benjamin Otte <otte@gnome.org>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA  02110-1301  USA
  18  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include <string.h>
  25 #include <zlib.h>
  26 #include <liboil/liboil.h>
  27
  28 #include "swfdec_codec_video.h"
  29 #include "swfdec_bits.h"
  30 #include "swfdec_debug.h"
  31 #include "swfdec_internal.h"
  32
  33 typedef struct _SwfdecCodecVp6Alpha SwfdecCodecVp6Alpha;
  34
  35 struct _SwfdecCodecVp6Alpha {
  36   SwfdecVideoDecoder    decoder;        /* the decoder */
  37   SwfdecVideoDecoder *  image;          /* the image decoder */
  38   SwfdecVideoDecoder *  alpha;          /* the alpha decoder */
  39 };
  40
  41 static gboolean
  42 swfdec_video_decoder_vp6_alpha_decode (SwfdecVideoDecoder *dec, SwfdecBuffer *buffer,
  43     SwfdecVideoImage *image)
  44 {
  45   SwfdecCodecVp6Alpha *vp6 = (SwfdecCodecVp6Alpha *) dec;
  46   SwfdecBuffer *tmp;
  47   SwfdecVideoImage alpha;
  48   SwfdecBits bits;
  49   guint size;
  50
  51   swfdec_bits_init (&bits, buffer);
  52   size = swfdec_bits_get_bu24 (&bits);
  53   tmp = swfdec_bits_get_buffer (&bits, size);
  54   if (tmp == NULL)
  55     return FALSE;
  56   if (!vp6->image->decode (vp6->image, tmp, image)) {
  57     swfdec_buffer_unref (tmp);
  58     return FALSE;
  59   }
  60   swfdec_buffer_unref (tmp);
  61   tmp = swfdec_bits_get_buffer (&bits, -1);
  62   if (tmp == NULL)
  63     return FALSE;
  64   if (!vp6->alpha->decode (vp6->alpha, tmp, &alpha)) {
  65     swfdec_buffer_unref (tmp);
  66     return FALSE;
  67   }
  68   swfdec_buffer_unref (tmp);
  69   if (alpha.width != image->width || alpha.height != image->height) {
  70     SWFDEC_ERROR ("size of mask doesn't match image: %ux%u vs %ux%u",
  71         alpha.width, alpha.height, image->width, image->height);
  72     return FALSE;
  73   }
  74   image->mask = alpha.plane[0];
  75   image->mask_rowstride = alpha.rowstride[0];
  76   return TRUE;
  77 }
  78
  79 static void
  80 swfdec_video_decoder_vp6_alpha_free (SwfdecVideoDecoder *dec)
  81 {
  82   SwfdecCodecVp6Alpha *vp6 = (SwfdecCodecVp6Alpha *) dec;
  83
  84   if (vp6->image)
  85     swfdec_video_decoder_free (vp6->image);
  86   if (vp6->alpha)
  87     swfdec_video_decoder_free (vp6->alpha);
  88   g_free (vp6);
  89 }
  90
  91 SwfdecVideoDecoder *
  92 swfdec_video_decoder_vp6_alpha_new (SwfdecVideoCodec type)
  93 {
  94   SwfdecCodecVp6Alpha *vp6;
  95
  96   if (type != SWFDEC_VIDEO_CODEC_VP6_ALPHA)
  97     return NULL;
  98
  99   vp6 = g_new0 (SwfdecCodecVp6Alpha, 1);
 100   vp6->decoder.decode = swfdec_video_decoder_vp6_alpha_decode;
 101   vp6->decoder.free = swfdec_video_decoder_vp6_alpha_free;
 102   vp6->image = swfdec_video_decoder_new (SWFDEC_VIDEO_CODEC_VP6);
 103   vp6->alpha = swfdec_video_decoder_new (SWFDEC_VIDEO_CODEC_VP6);
 104   if (vp6->alpha == NULL || vp6->image == NULL) {
 105     swfdec_video_decoder_vp6_alpha_free (&vp6->decoder);
 106     return NULL;
 107   }
 108
 109   return &vp6->decoder;
 110 }
 111