swfdec/swfdec_video_decoder_screen.c

   1 /* Swfdec
   2  * Copyright (C) 2007-2008 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 "swfdec_video_decoder_screen.h"
  25 #include "swfdec_bits.h"
  26 #include "swfdec_debug.h"
  27
  28 G_DEFINE_TYPE (SwfdecVideoDecoderScreen, swfdec_video_decoder_screen, SWFDEC_TYPE_VIDEO_DECODER)
  29
  30 static gboolean
  31 swfdec_video_decoder_screen_prepare (guint codec, char **missing)
  32 {
  33   return codec == SWFDEC_VIDEO_CODEC_SCREEN;
  34 }
  35
  36 static SwfdecVideoDecoder *
  37 swfdec_video_decoder_screen_create (guint codec)
  38 {
  39   if (codec != SWFDEC_VIDEO_CODEC_SCREEN)
  40     return NULL;
  41
  42   return g_object_new (SWFDEC_TYPE_VIDEO_DECODER_SCREEN, NULL);
  43 }
  44
  45 static void
  46 swfdec_video_decoder_screen_decode (SwfdecVideoDecoder *dec, SwfdecBuffer *buffer)
  47 {
  48   SwfdecBits bits;
  49   guint i, j, w, h, bw, bh, stride;
  50
  51   swfdec_bits_init (&bits, buffer);
  52   bw = (swfdec_bits_getbits (&bits, 4) + 1) * 16;
  53   w = swfdec_bits_getbits (&bits, 12);
  54   bh = (swfdec_bits_getbits (&bits, 4) + 1) * 16;
  55   h = swfdec_bits_getbits (&bits, 12);
  56   if (dec->width == 0 || dec->height == 0) {
  57     if (w == 0 || h == 0) {
  58       swfdec_video_decoder_error (dec, "width or height is 0: %ux%u", w, h);
  59       return;
  60     }
  61     /* check for overflow */
  62     if (w * 4 * h < w * 4) {
  63       swfdec_video_decoder_error (dec, "overflowing video size: %ux%u", w, h);
  64       return;
  65     }
  66     dec->plane[0] = g_try_malloc (w * h * 4);
  67     if (dec->plane[0] == NULL) {
  68       swfdec_video_decoder_error (dec, "could not allocate %u bytes", w * h * 4);
  69       return;
  70     }
  71     dec->width = w;
  72     dec->height = h;
  73     dec->rowstride[0] = w * 4;
  74   } else if (dec->width != w || dec->height != h) {
  75     swfdec_video_decoder_error (dec, "width or height differ from original: was %ux%u, is %ux%u",
  76         dec->width, dec->height, w, h);
  77     /* FIXME: this is what ffmpeg does, should we be more forgiving? */
  78     return;
  79   }
  80   stride = w * 4;
  81   SWFDEC_LOG ("size: %u x %u - block size %u x %u", w, h, bw, bh);
  82   for (j = 0; j < h; j += bh) {
  83     for (i = 0; i < w; i += bw) {
  84       guint x, y, size, curw, curh;
  85       SwfdecBuffer *buf;
  86       guint8 *in, *out;
  87       size = swfdec_bits_get_bu16 (&bits);
  88       if (size == 0)
  89         continue;
  90       curw = MIN (bw, w - i);
  91       curh = MIN (bh, h - j);
  92       buf = swfdec_bits_decompress (&bits, size, curw * curh * 3);
  93       if (buf == NULL) {
  94         SWFDEC_ERROR ("could not decode block at %ux%u", i, j);
  95         continue;
  96       }
  97       /* convert format and write out data */
  98       out = dec->plane[0] + stride * (h - j - 1) + i * 4;
  99       in = buf->data;
 100       for (y = 0; y < curh; y++) {
 101         for (x = 0; x < curw; x++) {
 102           out[x * 4 + SWFDEC_COLOR_INDEX_BLUE] = *in++;
 103           out[x * 4 + SWFDEC_COLOR_INDEX_GREEN] = *in++;
 104           out[x * 4 + SWFDEC_COLOR_INDEX_RED] = *in++;
 105           out[x * 4 + SWFDEC_COLOR_INDEX_ALPHA] = 0xFF;
 106         }
 107         out -= stride;
 108       }
 109       swfdec_buffer_unref (buf);
 110     }
 111   }
 112 }
 113
 114 static void
 115 swfdec_video_decoder_screen_dispose (GObject *object)
 116 {
 117   SwfdecVideoDecoder *dec = SWFDEC_VIDEO_DECODER (object);
 118
 119   g_free (dec->plane[0]);
 120
 121   G_OBJECT_CLASS (swfdec_video_decoder_screen_parent_class)->dispose (object);
 122 }
 123
 124 static void
 125 swfdec_video_decoder_screen_class_init (SwfdecVideoDecoderScreenClass *klass)
 126 {
 127   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 128   SwfdecVideoDecoderClass *decoder_class = SWFDEC_VIDEO_DECODER_CLASS (klass);
 129
 130   object_class->dispose = swfdec_video_decoder_screen_dispose;
 131
 132   decoder_class->prepare = swfdec_video_decoder_screen_prepare;
 133   decoder_class->create = swfdec_video_decoder_screen_create;
 134   decoder_class->decode = swfdec_video_decoder_screen_decode;
 135 }
 136
 137 static void
 138 swfdec_video_decoder_screen_init (SwfdecVideoDecoderScreen *dec)
 139 {
 140 }
 141