/indra/llimage/llimagedimensionsinfo.cpp
https://bitbucket.org/lindenlab/viewer-beta/ · C++ · 222 lines · 142 code · 37 blank · 43 comment · 21 complexity · 119f87edfde8f0cd862bd2c7cff05b39 MD5 · raw file
- /**
- * @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()
- {
- // Make sure the file is long enough.
- const S32 DATA_LEN = 26; // BMP header (14) + DIB header size (4) + width (4) + height (4)
- if (!checkFileLength(DATA_LEN))
- {
- llwarns << "Premature end of file" << llendl;
- return false;
- }
- // Read BMP signature.
- U8 signature[2];
- mInfile.read((void*)signature, sizeof(signature)/sizeof(signature[0]));
- // Make sure this is actually a BMP file.
- // We only support Windows bitmaps (BM), according to LLImageBMP::updateData().
- if (signature[0] != 'B' || signature[1] != 'M')
- {
- llwarns << "Not a BMP" << llendl;
- return false;
- }
- // Read image dimensions.
- mInfile.seek(APR_CUR, 16);
- mWidth = read_reverse_s32();
- mHeight = read_reverse_s32();
- return true;
- }
- bool LLImageDimensionsInfo::getImageDimensionsTga()
- {
- const S32 TGA_FILE_HEADER_SIZE = 12;
- // Make sure the file is long enough.
- if (!checkFileLength(TGA_FILE_HEADER_SIZE + 1 /* width */ + 1 /* height */))
- {
- llwarns << "Premature end of file" << llendl;
- return false;
- }
- // *TODO: Detect non-TGA files somehow.
- 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_MAGIC_SIZE = 8;
- // Make sure the file is long enough.
- if (!checkFileLength(PNG_MAGIC_SIZE + 8 + sizeof(S32) * 2 /* width, height */))
- {
- llwarns << "Premature end of file" << llendl;
- return false;
- }
- // Read PNG signature.
- const U8 png_magic[PNG_MAGIC_SIZE] = {0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A};
- U8 signature[PNG_MAGIC_SIZE];
- mInfile.read((void*)signature, PNG_MAGIC_SIZE);
- // Make sure it's a PNG file.
- if (memcmp(signature, png_magic, PNG_MAGIC_SIZE) != 0)
- {
- llwarns << "Not a PNG" << llendl;
- return false;
- }
- // Read image dimensions.
- mInfile.seek(APR_CUR, 8 /* 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;
- }
- /* Make sure this is a JPEG file. */
- const size_t JPEG_MAGIC_SIZE = 2;
- const uint8_t jpeg_magic[JPEG_MAGIC_SIZE] = {0xFF, 0xD8};
- uint8_t signature[JPEG_MAGIC_SIZE];
- if (fread(signature, sizeof(signature), 1, fp) != 1)
- {
- llwarns << "Premature end of file" << llendl;
- return false;
- }
- if (memcmp(signature, jpeg_magic, JPEG_MAGIC_SIZE) != 0)
- {
- llwarns << "Not a JPEG" << llendl;
- return false;
- }
- fseek(fp, 0, SEEK_SET); // go back to start of the file
- /* 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;
- }
- bool LLImageDimensionsInfo::checkFileLength(S32 min_len)
- {
- // Make sure the file is not shorter than min_len bytes.
- // so that we don't have to check value returned by each read() or seek().
- char* buf = new char[min_len];
- int nread = mInfile.read(buf, min_len);
- delete[] buf;
- mInfile.seek(APR_SET, 0);
- return nread == min_len;
- }