swfdec_image.c

Swfdec is a decoder/renderer for Macromedia Flash animations. The decoding and rendering engine is

/* Swfdec
 * Copyright (C) 2003-2006 David Schleef <[e-mail]>
 *		 2005-2006 Eric Anholt <[e-mail]>
 *		 2006-2007 Benjamin Otte <[e-mail]>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, 
 * Boston, MA  02110-1301  USA
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <zlib.h>
#include <string.h>

#include "jpeg.h"
#include "swfdec_image.h"
#include "swfdec_cache.h"
#include "swfdec_debug.h"
#include "swfdec_swf_decoder.h"


static void merge_alpha (SwfdecImage * image, unsigned char *image_data,
    unsigned char *alpha);
static void swfdec_image_colormap_decode (SwfdecImage * image,
    unsigned char *dest,
    unsigned char *src, unsigned char *colormap, int colormap_len);

G_DEFINE_TYPE (SwfdecImage, swfdec_image, SWFDEC_TYPE_CACHED)

static void
swfdec_image_unload (SwfdecCached *cached)
{
  SwfdecImage *image = SWFDEC_IMAGE (cached);

  if (image->surface) {
    cairo_surface_destroy (image->surface);
    image->surface = NULL;
  } else if (image->data) {
    g_free (image->data);
  }
  image->data = NULL;
}

static void
swfdec_image_dispose (GObject *object)
{
  SwfdecImage * image = SWFDEC_IMAGE (object);

  if (image->jpegtables) {
    swfdec_buffer_unref (image->jpegtables);
    image->jpegtables = NULL;
  }
  if (image->raw_data) {
    swfdec_buffer_unref (image->raw_data);
    image->raw_data = NULL;
  }

  G_OBJECT_CLASS (swfdec_image_parent_class)->dispose (object);
}

static void
swfdec_image_class_init (SwfdecImageClass * g_class)
{
  GObjectClass *object_class = G_OBJECT_CLASS (g_class);
  SwfdecCachedClass *cached_class = SWFDEC_CACHED_CLASS (g_class);

  object_class->dispose = swfdec_image_dispose;

  cached_class->unload = swfdec_image_unload;
}

static void
swfdec_image_init (SwfdecImage * image)
{
}

int
swfdec_image_jpegtables (SwfdecSwfDecoder * s, guint tag)
{
  SwfdecBits *bits = &s->b;

  SWFDEC_DEBUG ("swfdec_image_jpegtables");

  if (s->jpegtables) {
    SWFDEC_FIXME ("duplicate DefineJPEGTables tag. Deleting first one");
    swfdec_buffer_unref (s->jpegtables);
  }
  s->jpegtables = swfdec_bits_get_buffer (bits, -1);

  return SWFDEC_STATUS_OK;
}

int
tag_func_define_bits_jpeg (SwfdecSwfDecoder * s, guint tag)
{
  SwfdecBits *bits = &s->b;
  int id;
  SwfdecImage *image;

  SWFDEC_LOG ("tag_func_define_bits_jpeg");
  id = swfdec_bits_get_u16 (bits);
  SWFDEC_LOG ("  id = %d", id);

  image = swfdec_swf_decoder_create_character (s, id, SWFDEC_TYPE_IMAGE);
  if (!image)
    return SWFDEC_STATUS_OK;

  image->type = SWFDEC_IMAGE_TYPE_JPEG;
  if (!s->jpegtables) {
    SWFDEC_ERROR("No global JPEG tables available");
  } else {
    image->jpegtables = swfdec_buffer_ref (s->jpegtables);
  }
  image->raw_data = swfdec_bits_get_buffer (bits, -1);

  return SWFDEC_STATUS_OK;
}

/**
 * swfdec_jpeg_decode_argb:
 *
 * This is a wrapper around jpeg_decode_argb() that takes two segments,
 * strips off (sometimes bogus) start-of-image and end-of-image codes,
 * concatenates them, and puts new SOI and EOI codes on the resulting
 * buffer.  This makes a real JPEG image out of the crap in SWF files.
 */
static gboolean
swfdec_jpeg_decode_argb (unsigned char *data1, int length1,
    unsigned char *data2, int length2,
    void *outdata, int *width, int *height)
{
  gboolean ret;

  if (data2) {
    unsigned char *tmpdata;
    int tmplength;

    tmplength = length1 + length2;
    tmpdata = g_malloc (tmplength);

    memcpy (tmpdata, data1, length1);
    memcpy (tmpdata + length1, data2, length2);
    ret = jpeg_decode_argb (tmpdata, tmplength, outdata, width, height);

    g_free (tmpdata);
  } else {
    ret = jpeg_decode_argb (data1, length1, outdata, width, height);
  }

  return ret;
}

static void
swfdec_image_jpeg_load (SwfdecImage *image)
{
  gboolean ret;

  if (image->jpegtables) {
    ret = swfdec_jpeg_decode_argb (
        image->jpegtables->data, image->jpegtables->length,
        image->raw_data->data, image->raw_data->length,
        (void *)&image->data, &image->width, &image->height);
  } else {
    ret = swfdec_jpeg_decode_argb (
        image->raw_data->data, image->raw_data->length,
        NULL, 0,
        (void *)&image->data, &image->width, &image->height);
  }

  if (!ret) {
    return;
  }

  swfdec_cached_load (SWFDEC_CACHED (image), 4 * image->width * image->height);
  image->rowstride = image->width * 4;

  SWFDEC_LOG ("  width = %d", image->width);
  SWFDEC_LOG ("  height = %d", image->height);
}

int
tag_func_define_bits_jpeg_2 (SwfdecSwfDecoder * s, guint tag)
{
  SwfdecBits *bits = &s->b;
  int id;
  SwfdecImage *image;

  id = swfdec_bits_get_u16 (bits);
  SWFDEC_LOG ("  id = %d", id);

  image = swfdec_swf_decoder_create_character (s, id, SWFDEC_TYPE_IMAGE);
  if (!image)
    return SWFDEC_STATUS_OK;

  image->type = SWFDEC_IMAGE_TYPE_JPEG2;
  image->raw_data = swfdec_bits_get_buffer (bits, -1);

  return SWFDEC_STATUS_OK;
}

static void
swfdec_image_jpeg2_load (SwfdecImage *image)
{
  gboolean ret;

  ret = swfdec_jpeg_decode_argb (image->raw_data->data, image->raw_data->length,
      NULL, 0,
      (void *)&image->data, &image->width, &image->height);
  if (!ret) {
    return;
  }

  swfdec_cached_load (SWFDEC_CACHED (image), 4 * image->width * image->height);
  image->rowstride = image->width * 4;

  SWFDEC_LOG ("  width = %d", image->width);
  SWFDEC_LOG ("  height = %d", image->height);
}

int
tag_func_define_bits_jpeg_3 (SwfdecSwfDecoder * s, guint tag)
{
  SwfdecBits *bits = &s->b;
  guint id;
  SwfdecImage *image;

  id = swfdec_bits_get_u16 (bits);
  SWFDEC_LOG ("  id = %d", id);

  image = swfdec_swf_decoder_create_character (s, id, SWFDEC_TYPE_IMAGE);
  if (!image)
    return SWFDEC_STATUS_OK;

  image->type = SWFDEC_IMAGE_TYPE_JPEG3;
  image->raw_data = swfdec_bits_get_buffer (bits, -1);

  return SWFDEC_STATUS_OK;
}

static void
swfdec_image_jpeg3_load (SwfdecImage *image)
{
  SwfdecBits bits;
  SwfdecBuffer *buffer;
  int jpeg_length;
  gboolean ret;

  swfdec_bits_init (&bits, image->raw_data);

  jpeg_length = swfdec_bits_get_u32 (&bits);
  buffer = swfdec_bits_get_buffer (&bits, jpeg_length);
  if (buffer == NULL)
    return;

  ret = swfdec_jpeg_decode_argb (buffer->data, buffer->length,
      NULL, 0,
      (void *)&image->data, &image->width, &image->height);
  swfdec_buffer_unref (buffer);

  if (!ret) {
    return;
  }

  swfdec_cached_load (SWFDEC_CACHED (image), 4 * image->width * image->height);
  image->rowstride = image->width * 4;

  buffer = swfdec_bits_decompress (&bits, -1, image->width * image->height);
  if (buffer) {
    merge_alpha (image, image->data, buffer->data);
    swfdec_buffer_unref (buffer);
  } else {
    SWFDEC_WARNING ("cannot set alpha channel information, decompression failed");
  }

  SWFDEC_LOG ("  width = %d", image->width);
  SWFDEC_LOG ("  height = %d", image->height);
}

static void
merge_alpha (SwfdecImage * image, unsigned char *image_data,
    unsigned char *alpha)
{
  int x, y;
  unsigned char *p;

  for (y = 0; y < image->height; y++) {
    p = image_data + y * image->rowstride;
    for (x = 0; x < image->width; x++) {
      p[SWFDEC_COLOR_INDEX_ALPHA] = *alpha;
      p += 4;
      alpha++;
    }
  }
}

static void
swfdec_image_lossless_load (SwfdecImage *image)
{
  int format;
  guint color_table_size;
  unsigned char *ptr;
  SwfdecBits bits;
  int have_alpha = (image->type == SWFDEC_IMAGE_TYPE_LOSSLESS2);

  swfdec_bits_init (&bits, image->raw_data);

  format = swfdec_bits_get_u8 (&bits);
  SWFDEC_LOG ("  format = %d", format);
  image->width = swfdec_bits_get_u16 (&bits);
  SWFDEC_LOG ("  width = %d", image->width);
  image->height = swfdec_bits_get_u16 (&bits);
  SWFDEC_LOG ("  height = %d", image->height);
  if (format == 3) {
    color_table_size = swfdec_bits_get_u8 (&bits) + 1;
  } else {
    color_table_size = 0;