exiv2/src/pngimage.cpp

// ***************************************************************** -*- C++ -*-
/*
 * Copyright (C) 2004-2008 Andreas Huggel <ahuggel@gmx.net>
 *
 * This program is part of the Exiv2 distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, 5th Floor, Boston, MA 02110-1301 USA.
 */
/*
  File:    pngimage.cpp
  Version: $Rev: 823 $
  Author(s): Gilles Caulier (cgilles) <caulier dot gilles at gmail dot com>
  History: 12-Jun-06, gc: submitted
  Credits: See header file
 */
// *****************************************************************************
#include "rcsid.hpp"
EXIV2_RCSID("@(#) $Id: pngimage.cpp 823 2006-06-12 07:35:00Z cgilles $")

// *****************************************************************************

//#define DEBUG 1

// *****************************************************************************
// included header files
#ifdef _MSC_VER
# include "exv_msvc.h"
#else
# include "exv_conf.h"
#endif

#include "pngchunk.hpp"
#include "pngimage.hpp"
#include "image.hpp"
#include "basicio.hpp"
#include "error.hpp"
#include "futils.hpp"

// + standard includes
#include <string>
#include <cstring>
#include <iostream>
#include <cassert>

// Signature from front of PNG file 
const unsigned char pngSignature[8] = { 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A };

// *****************************************************************************
// class member definitions
namespace Exiv2 
{
    PngImage::PngImage(BasicIo::AutoPtr io, bool /*create*/)
            : Image(ImageType::png, mdExif | mdIptc | mdComment, io)
    {
    } // PngImage::PngImage

    void PngImage::readMetadata()
    {
#ifdef DEBUG
        std::cerr << "Exiv2::PngImage::readMetadata: Reading PNG file " << io_->path() << "\n";
#endif
        if (io_->open() != 0)
        {
            throw Error(9, io_->path(), strError());
        }
        IoCloser closer(*io_);
        // Ensure that this is the correct image type
        if (!isPngType(*io_, true))
        {
            if (io_->error() || io_->eof()) throw Error(14);
            throw Error(3, "PNG");
        }
        clearMetadata();

        DataBuf cheaderBuf(8);       // Chunk header size : 4 bytes (data size) + 4 bytes (chunk type).

        while(!io_->eof())
        {
            // Read chunk header.

#ifdef DEBUG
            std::cout << "Exiv2::PngImage::readMetadata: Position: " << io_->tell() << "\n";
#endif
            std::memset(cheaderBuf.pData_, 0x0, cheaderBuf.size_);
            long bufRead = io_->read(cheaderBuf.pData_, cheaderBuf.size_);
            if (io_->error()) throw Error(14);
            if (bufRead != cheaderBuf.size_) throw Error(20);

#ifdef DEBUG
            std::cout << "Exiv2::PngImage::readMetadata: Next Chunk: " << cheaderBuf.pData_ + 4 << "\n";
#endif
            // Decode chunk data length.

            uint32_t dataOffset = Exiv2::getULong(cheaderBuf.pData_, Exiv2::bigEndian);
            if (dataOffset > 0x7FFFFFFF) throw Exiv2::Error(14);

            // Perform a chunk triage for item that we need.

            if (!memcmp(cheaderBuf.pData_ + 4, "IEND", 4) ||
                !memcmp(cheaderBuf.pData_ + 4, "IHDR", 4) ||
                !memcmp(cheaderBuf.pData_ + 4, "tEXt", 4) ||
                !memcmp(cheaderBuf.pData_ + 4, "zTXt", 4) ||
                !memcmp(cheaderBuf.pData_ + 4, "iTXt", 4))
            {
                // Extract chunk data. 

                DataBuf cdataBuf(dataOffset);
                bufRead = io_->read(cdataBuf.pData_, dataOffset);
                if (io_->error()) throw Error(14);
                if (bufRead != (long)dataOffset) throw Error(20);

                if (!memcmp(cheaderBuf.pData_ + 4, "IEND", 4))
                {
                    // Last chunk found: we stop parsing.
#ifdef DEBUG
                    std::cout << "Exiv2::PngImage::readMetadata: Found IEND chunk (lenght: " << dataOffset << ")\n";
#endif
                    return;
                }
                else if (!memcmp(cheaderBuf.pData_ + 4, "IHDR", 4))
                {
#ifdef DEBUG
                    std::cout << "Exiv2::PngImage::readMetadata: Found IHDR chunk (lenght: " << dataOffset << ")\n";
#endif
                    PngChunk::decodeIHDRChunk(cdataBuf, &pixelWidth_, &pixelHeight_);
                }
                else if (!memcmp(cheaderBuf.pData_ + 4, "tEXt", 4))
                {
#ifdef DEBUG
                    std::cout << "Exiv2::PngImage::readMetadata: Found tEXt chunk (lenght: " << dataOffset << ")\n";
#endif
                    PngChunk::decodeTXTChunk(this, cdataBuf, PngChunk::tEXt_Chunk);
                }
                else if (!memcmp(cheaderBuf.pData_ + 4, "zTXt", 4))
                {
#ifdef DEBUG
                    std::cout << "Exiv2::PngImage::readMetadata: Found zTXt chunk (lenght: " << dataOffset << ")\n";
#endif
                    PngChunk::decodeTXTChunk(this, cdataBuf, PngChunk::zTXt_Chunk);
                }
                else if (!memcmp(cheaderBuf.pData_ + 4, "iTXt", 4))
                {
#ifdef DEBUG
                    std::cout << "Exiv2::PngImage::readMetadata: Found iTXt chunk (lenght: " << dataOffset << ")\n";
#endif
                    PngChunk::decodeTXTChunk(this, cdataBuf, PngChunk::iTXt_Chunk);
                }

                // Set dataOffset to null like chunk data have been extracted previously.
                dataOffset = 0;
            }

            // Move to the next chunk: chunk data size + 4 CRC bytes.
#ifdef DEBUG
            std::cout << "Exiv2::PngImage::readMetadata: Seek to offset: " << dataOffset + 4 << "\n";
#endif
            io_->seek(dataOffset + 4 , BasicIo::cur);
            if (io_->error() || io_->eof()) throw Error(14);
        }

    } // PngImage::readMetadata

    void PngImage::writeMetadata()
    {
        if (io_->open() != 0) 
        {
            throw Error(9, io_->path(), strError());
        }
        IoCloser closer(*io_);
        BasicIo::AutoPtr tempIo(io_->temporary()); // may throw
        assert (tempIo.get() != 0);

        doWriteMetadata(*tempIo); // may throw
        io_->close();
        io_->transfer(*tempIo); // may throw

    } // PngImage::writeMetadata

    void PngImage::doWriteMetadata(BasicIo& outIo)
    {
        if (!io_->isopen()) throw Error(20);
        if (!outIo.isopen()) throw Error(21);

#ifdef DEBUG
        std::cout << "Exiv2::PngImage::doWriteMetadata: Writing PNG file " << io_->path() << "\n";
        std::cout << "Exiv2::PngImage::doWriteMetadata: tmp file created " << outIo.path() << "\n";
#endif

        // Ensure that this is the correct image type
        if (!isPngType(*io_, true))
        {
            if (io_->error() || io_->eof()) throw Error(20);
            throw Error(22);
        }

        // Write PNG Signature.
        if (outIo.write(pngSignature, 8) != 8) throw Error(21);

        DataBuf cheaderBuf(8);       // Chunk header : 4 bytes (data size) + 4 bytes (chunk type).

        while(!io_->eof())
        {
            // Read chunk header.

            std::memset(cheaderBuf.pData_, 0x00, cheaderBuf.size_);
            long bufRead = io_->read(cheaderBuf.pData_, cheaderBuf.size_);
            if (io_->error()) throw Error(14);
            if (bufRead != cheaderBuf.size_) throw Error(20);

            // Decode chunk data length.

            uint32_t dataOffset = getULong(cheaderBuf.pData_, bigEndian);
            if (dataOffset > 0x7FFFFFFF) throw Exiv2::Error(14);

            // Read whole chunk : Chunk header + Chunk data (not fixed size - can be null) + CRC (4 bytes).

            DataBuf chunkBuf(8 + dataOffset + 4);                     // Chunk header (8 bytes) + Chunk data + CRC (4 bytes).
            memcpy(chunkBuf.pData_, cheaderBuf.pData_, 8);            // Copy header.
            bufRead = io_->read(chunkBuf.pData_ + 8, dataOffset + 4); // Extract chunk data + CRC
            if (io_->error()) throw Error(14);
            if (bufRead != (long)(dataOffset + 4)) throw Error(20);

            if (!memcmp(cheaderBuf.pData_ + 4, "IEND", 4))
            {
                // Last chunk found: we write it and done.
#ifdef DEBUG
                std::cout << "Exiv2::PngImage::doWriteMetadata: Write IEND chunk (lenght: " << dataOffset << ")\n";
#endif
                if (outIo.write(chunkBuf.pData_, chunkBuf.size_) != chunkBuf.size_) throw Error(21);
                return;
            }
            else if (!memcmp(cheaderBuf.pData_ + 4, "IHDR", 4))
            {
#ifdef DEBUG
                std::cout << "Exiv2::PngImage::doWriteMetadata: Write IHDR chunk (lenght: " << dataOffset << ")\n";
#endif
                if (outIo.write(chunkBuf.pData_, chunkBuf.size_) != chunkBuf.size_) throw Error(21);

                // Write all updated metadata here, just after IHDR.

                if (!comment_.empty()) 
                {
                    // Update Comment data to a new compressed iTXt PNG chunk

                    DataBuf com(reinterpret_cast<const byte*>(comment_.data()), static_cast<long>(comment_.size()));
                    DataBuf chunkData = PngChunk::makeMetadataChunk(com, PngChunk::comment_Data, true);

#ifdef DEBUG
                    std::cout << "Exiv2::PngImage::doWriteMetadata: Write chunk with Comment metadata (lenght: " 
                              << chunkData.size_ << ")\n";
#endif
                    if (outIo.write(chunkData.pData_, chunkData.size_) != chunkData.size_) throw Error(21);
                }

                if (exifData_.count() > 0) 
                {
                    // Update Exif data to a new zTXt PNG chunk

                    Blob blob;
                    ExifParser::encode(blob, littleEndian, exifData_);
                    if (blob.size()) 
                    {
                        const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};

                        DataBuf rawExif(sizeof(ExifHeader) + blob.size());
                        memcpy(rawExif.pData_, ExifHeader, sizeof(ExifHeader));
                        memcpy(rawExif.pData_ + sizeof(ExifHeader), &blob[0], blob.size());
                        DataBuf chunkData = PngChunk::makeMetadataChunk(rawExif, PngChunk::exif_Data, true);

#ifdef DEBUG
                        std::cout << "Exiv2::PngImage::doWriteMetadata: Write chunk with Exif metadata (lenght: " 
                                  << chunkData.size_ << ")\n";
#endif
                        if (outIo.write(chunkData.pData_, chunkData.size_) != chunkData.size_) throw Error(21);
                    }
                }

                if (iptcData_.count() > 0) 
                {
                    // Update Iptc data to a new zTXt PNG chunk

                    DataBuf rawIptc = IptcParser::encode(iptcData_);
                    if (rawIptc.size_ > 0) 
                    {
                        DataBuf chunkData = PngChunk::makeMetadataChunk(rawIptc, PngChunk::iptc_Data, true);

#ifdef DEBUG
                        std::cout << "Exiv2::PngImage::doWriteMetadata: Write chunk with Iptc metadata (lenght: " 
                                  << chunkData.size_ << ")\n";
#endif
                        if (outIo.write(chunkData.pData_, chunkData.size_) != chunkData.size_) throw Error(21);
                    }
                }

                if (writeXmpFromPacket() == false) 
                {
                    if (XmpParser::encode(xmpPacket_, xmpData_)) 
                    {
#ifndef SUPPRESS_WARNINGS
                        std::cerr << "Error: Failed to encode XMP metadata.\n";
#endif
                    }
                }
                if (xmpPacket_.size() > 0) 
                {
                    // Update Xmp data to a new uncompressed iTXt PNG chunk
                    // Note than XMP spec. Ver September 2005, page 97 require an uncompressed chunk to host XMP data

                    DataBuf xmp(reinterpret_cast<const byte*>(xmpPacket_.data()), static_cast<long>(xmpPacket_.size()));
                    DataBuf chunkData = PngChunk::makeMetadataChunk(xmp, PngChunk::xmp_Data, false);

#ifdef DEBUG
                    std::cout << "Exiv2::PngImage::doWriteMetadata: Write chunk with XMP metadata (lenght: " 
                              << chunkData.size_ << ")\n";
#endif
                    if (outIo.write(chunkData.pData_, chunkData.size_) != chunkData.size_) throw Error(21);
                }
            }
            else if (!memcmp(cheaderBuf.pData_ + 4, "tEXt", 4) ||
                     !memcmp(cheaderBuf.pData_ + 4, "zTXt", 4) ||
                     !memcmp(cheaderBuf.pData_ + 4, "iTXt", 4))
            {
                DataBuf key = PngChunk::keyTXTChunk(chunkBuf, true);
                if (memcmp("Raw profile type exif", key.pData_, 21) == 0 ||
                    memcmp("Raw profile type APP1", key.pData_, 21) == 0 ||
                    memcmp("Raw profile type iptc", key.pData_, 21) == 0 ||
                    memcmp("Raw profile type xmp",  key.pData_, 20) == 0 ||
                    memcmp("XML:com.adobe.xmp",     key.pData_, 17) == 0 ||
                    memcmp("Description",           key.pData_, 11) == 0)
                {
#ifdef DEBUG
                    std::cout << "Exiv2::PngImage::doWriteMetadata: strip " << cheaderBuf.pData_ + 4 
                              << " chunk (key: " << key.pData_ << ")\n";
#endif
                }
                else
                {
#ifdef DEBUG
                    std::cout << "Exiv2::PngImage::doWriteMetadata: write " << cheaderBuf.pData_ + 4 
                              << " chunk (lenght: " << dataOffset << ")\n";
#endif
                    if (outIo.write(chunkBuf.pData_, chunkBuf.size_) != chunkBuf.size_) throw Error(21);
                }
            }
            else
            {
                // Write all others chunk as well.
#ifdef DEBUG
                std::cout << "Exiv2::PngImage::doWriteMetadata: write " << cheaderBuf.pData_ + 4 
                          << " chunk (lenght: " << dataOffset << ")\n";
#endif
                if (outIo.write(chunkBuf.pData_, chunkBuf.size_) != chunkBuf.size_) throw Error(21);

            }
        }

    } // PngImage::doWriteMetadata

    // *************************************************************************
    // free functions
    Image::AutoPtr newPngInstance(BasicIo::AutoPtr io, bool create)
    {
        Image::AutoPtr image(new PngImage(io, create));
        if (!image->good())
        {
            image.reset();
        }
        return image;
    }

    bool isPngType(BasicIo& iIo, bool advance)
    {
        const int32_t len = 8;
        byte buf[len];
        iIo.read(buf, len);
        if (iIo.error() || iIo.eof())
        {
            return false;
        }
        int rc = memcmp(buf, pngSignature, 8);
        if (!advance || rc != 0)
        {
            iIo.seek(-len, BasicIo::cur);
        }

        return rc == 0;
    }
}                                       // namespace Exiv2