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Diffstat (limited to 'indra/llimage/llimagedimensionsinfo.cpp')
| -rwxr-xr-x | indra/llimage/llimagedimensionsinfo.cpp | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/indra/llimage/llimagedimensionsinfo.cpp b/indra/llimage/llimagedimensionsinfo.cpp new file mode 100755 index 0000000000..5bf3f29b3c --- /dev/null +++ b/indra/llimage/llimagedimensionsinfo.cpp @@ -0,0 +1,222 @@ +/** + * @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)) + { + LL_WARNS() << "Premature end of file" << LL_ENDL; + 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') + { + LL_WARNS() << "Not a BMP" << LL_ENDL; + 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 */)) + { + LL_WARNS() << "Premature end of file" << LL_ENDL; + 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 */)) + { + LL_WARNS() << "Premature end of file" << LL_ENDL; + 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) + { + LL_WARNS() << "Not a PNG" << LL_ENDL; + 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; + LL_WARNS() << "Libjpeg has encountered an error!" << LL_ENDL; +} + +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 U8 jpeg_magic[JPEG_MAGIC_SIZE] = {0xFF, 0xD8}; + U8 signature[JPEG_MAGIC_SIZE]; + + if (fread(signature, sizeof(signature), 1, fp) != 1) + { + LL_WARNS() << "Premature end of file" << LL_ENDL; + return false; + } + if (memcmp(signature, jpeg_magic, JPEG_MAGIC_SIZE) != 0) + { + LL_WARNS() << "Not a JPEG" << LL_ENDL; + 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; +} |