phoenix-firestorm/indra/llimage/llimagedimensionsinfo.cpp

148 lines
3.6 KiB
C++

/**
* @file llimagedimensionsinfo.cpp
*
* $LicenseInfo:firstyear=2002&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* 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;
* version 2.1 of the License only.
*
* 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
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#include "linden_common.h"
#include "stdtypes.h"
#include "llimagejpeg.h"
#include "llimagedimensionsinfo.h"
// Value is true if one of Libjpeg's functions has encountered an error while working.
static bool sJpegErrorEncountered = false;
bool LLImageDimensionsInfo::load(const std::string& src_filename,U32 codec)
{
clean();
mSrcFilename = src_filename;
S32 file_size = 0;
apr_status_t s = mInfile.open(src_filename, LL_APR_RB, NULL, &file_size);
if (s != APR_SUCCESS)
{
setLastError("Unable to open file for reading", src_filename);
return false;
}
if (file_size == 0)
{
setLastError("File is empty",src_filename);
return false;
}
switch (codec)
{
case IMG_CODEC_BMP:
return getImageDimensionsBmp();
case IMG_CODEC_TGA:
return getImageDimensionsTga();
case IMG_CODEC_JPEG:
return getImageDimensionsJpeg();
case IMG_CODEC_PNG:
return getImageDimensionsPng();
default:
return false;
}
}
bool LLImageDimensionsInfo::getImageDimensionsBmp()
{
const S32 BMP_FILE_HEADER_SIZE = 14;
mInfile.seek(APR_CUR,BMP_FILE_HEADER_SIZE+4);
mWidth = read_reverse_s32();
mHeight = read_reverse_s32();
return true;
}
bool LLImageDimensionsInfo::getImageDimensionsTga()
{
const S32 TGA_FILE_HEADER_SIZE = 12;
mInfile.seek(APR_CUR,TGA_FILE_HEADER_SIZE);
mWidth = read_byte() | read_byte() << 8;
mHeight = read_byte() | read_byte() << 8;
return true;
}
bool LLImageDimensionsInfo::getImageDimensionsPng()
{
const S32 PNG_FILE_MARKER_SIZE = 8;
mInfile.seek(APR_CUR,PNG_FILE_MARKER_SIZE + 8/*header offset+chunk length+chunk type*/);
mWidth = read_s32();
mHeight = read_s32();
return true;
}
// Called instead of exit() if Libjpeg encounters an error.
void on_jpeg_error(j_common_ptr cinfo)
{
(void) cinfo;
sJpegErrorEncountered = true;
llwarns << "Libjpeg has encountered an error!" << llendl;
}
bool LLImageDimensionsInfo::getImageDimensionsJpeg()
{
sJpegErrorEncountered = false;
clean();
FILE *fp = fopen (mSrcFilename.c_str(), "rb");
if (fp == NULL)
{
setLastError("Unable to open file for reading", mSrcFilename);
return false;
}
/* Init jpeg */
jpeg_error_mgr jerr;
jpeg_decompress_struct cinfo;
cinfo.err = jpeg_std_error(&jerr);
// Call our function instead of exit() if Libjpeg encounters an error.
// This is done to avoid crash in this case (STORM-472).
cinfo.err->error_exit = on_jpeg_error;
jpeg_create_decompress (&cinfo);
jpeg_stdio_src (&cinfo, fp);
jpeg_read_header (&cinfo, TRUE);
cinfo.out_color_space = JCS_RGB;
jpeg_start_decompress (&cinfo);
mHeight = cinfo.output_width;
mHeight = cinfo.output_height;
jpeg_destroy_decompress(&cinfo);
fclose(fp);
return !sJpegErrorEncountered;
}