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Viewing changes to lib/iodevicejpegsourcemanager.cpp

  • Committer: Package Import Robot
  • Author(s): Jonathan Riddell
  • Date: 2011-12-15 14:17:54 UTC
  • mto: This revision was merged to the branch mainline in revision 12.
  • Revision ID: package-import@ubuntu.com-20111215141754-z043hyx69dulbggf
Tags: upstream-4.7.90
Import upstream version 4.7.90

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lib/iodevicejpegsourcemanager.cpp
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// vim: set tabstop=4 shiftwidth=4 noexpandtab:
 
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// vim: set tabstop=4 shiftwidth=4 expandtab:
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/*
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Gwenview: an image viewer
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Copyright 2008 Aurélien Gâteau <agateau@kde.org>
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// Local
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namespace Gwenview {
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namespace IODeviceJpegSourceManager {
 
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namespace Gwenview
 
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{
 
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namespace IODeviceJpegSourceManager
 
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{
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#define SOURCE_MANAGER_BUFFER_SIZE 4096
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struct IODeviceJpegSourceManager : public jpeg_source_mgr {
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        QIODevice* mIODevice;
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        JOCTET mBuffer[SOURCE_MANAGER_BUFFER_SIZE];
 
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    QIODevice* mIODevice;
 
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    JOCTET mBuffer[SOURCE_MANAGER_BUFFER_SIZE];
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};
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static boolean fill_input_buffer(j_decompress_ptr cinfo) {
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        IODeviceJpegSourceManager* src = static_cast<IODeviceJpegSourceManager*>(cinfo->src);
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        Q_ASSERT(src->mIODevice);
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        int readSize = src->mIODevice->read((char*)src->mBuffer, SOURCE_MANAGER_BUFFER_SIZE);
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        if (readSize > 0) {
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                src->next_input_byte = src->mBuffer;
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                src->bytes_in_buffer = readSize;
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        } else {
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                /**
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                 * JPEG file is broken. We feed the decoder with fake EOI, as specified
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                 * in the libjpeg documentation.
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                 */
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                static JOCTET fakeEOI[2] = { JOCTET(0xFF), JOCTET(JPEG_EOI)};
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                kWarning() << "Image is incomplete";
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                cinfo->src->next_input_byte = fakeEOI;
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                cinfo->src->bytes_in_buffer = 2;
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        }
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        return true;
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}
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static void init_source(j_decompress_ptr cinfo) {
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        fill_input_buffer(cinfo);
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}
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static void skip_input_data(j_decompress_ptr cinfo, long num_bytes) {
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        if (num_bytes > 0) {
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                while (num_bytes > (long) cinfo->src->bytes_in_buffer) {
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                        num_bytes -= (long) cinfo->src->bytes_in_buffer;
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                        fill_input_buffer(cinfo);
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                        /**
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                         * we assume that fill_input_buffer will never return FALSE, so
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                         * suspension need not be handled.
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                         */
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                }
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                cinfo->src->next_input_byte += (size_t) num_bytes;
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                cinfo->src->bytes_in_buffer -= (size_t) num_bytes;
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        }
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}
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static void term_source(j_decompress_ptr) {
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}
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void setup(j_decompress_ptr cinfo, QIODevice* ioDevice) {
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        Q_ASSERT(!cinfo->src);
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        IODeviceJpegSourceManager* src = (IODeviceJpegSourceManager*)
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                (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
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                                                                        sizeof(IODeviceJpegSourceManager));
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        cinfo->src = src;
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        src->init_source = init_source;
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        src->fill_input_buffer = fill_input_buffer;
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        src->skip_input_data = skip_input_data;
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        src->resync_to_restart = jpeg_resync_to_restart;
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        src->term_source = term_source;
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        src->mIODevice = ioDevice;
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}
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static boolean fill_input_buffer(j_decompress_ptr cinfo)
 
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{
 
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    IODeviceJpegSourceManager* src = static_cast<IODeviceJpegSourceManager*>(cinfo->src);
 
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    Q_ASSERT(src->mIODevice);
 
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    int readSize = src->mIODevice->read((char*)src->mBuffer, SOURCE_MANAGER_BUFFER_SIZE);
 
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    if (readSize > 0) {
 
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        src->next_input_byte = src->mBuffer;
 
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        src->bytes_in_buffer = readSize;
 
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    } else {
 
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        /**
 
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         * JPEG file is broken. We feed the decoder with fake EOI, as specified
 
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         * in the libjpeg documentation.
 
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         */
 
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        static JOCTET fakeEOI[2] = { JOCTET(0xFF), JOCTET(JPEG_EOI)};
 
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        kWarning() << "Image is incomplete";
 
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        cinfo->src->next_input_byte = fakeEOI;
 
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        cinfo->src->bytes_in_buffer = 2;
 
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    }
 
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    return true;
 
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}
 
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static void init_source(j_decompress_ptr cinfo)
 
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{
 
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    fill_input_buffer(cinfo);
 
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}
 
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static void skip_input_data(j_decompress_ptr cinfo, long num_bytes)
 
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{
 
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    if (num_bytes > 0) {
 
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        while (num_bytes > (long) cinfo->src->bytes_in_buffer) {
 
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            num_bytes -= (long) cinfo->src->bytes_in_buffer;
 
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            fill_input_buffer(cinfo);
 
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            /**
 
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             * we assume that fill_input_buffer will never return FALSE, so
 
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             * suspension need not be handled.
 
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             */
 
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        }
 
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        cinfo->src->next_input_byte += (size_t) num_bytes;
 
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        cinfo->src->bytes_in_buffer -= (size_t) num_bytes;
 
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    }
 
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}
 
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static void term_source(j_decompress_ptr)
 
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{
 
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}
 
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void setup(j_decompress_ptr cinfo, QIODevice* ioDevice)
 
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{
 
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    Q_ASSERT(!cinfo->src);
 
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    IODeviceJpegSourceManager* src = (IODeviceJpegSourceManager*)
 
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                                     (*cinfo->mem->alloc_small)((j_common_ptr) cinfo, JPOOL_PERMANENT,
 
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                                             sizeof(IODeviceJpegSourceManager));
 
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    cinfo->src = src;
 
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    src->init_source = init_source;
 
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    src->fill_input_buffer = fill_input_buffer;
 
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    src->skip_input_data = skip_input_data;
 
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    src->resync_to_restart = jpeg_resync_to_restart;
 
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    src->term_source = term_source;
 
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    src->mIODevice = ioDevice;
 
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}
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} // IODeviceJpegSourceManager namespace
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} // Gwenview namespace