JPEGImageDecoder.cpp   [plain text]

/*
 * Copyright (C) 2006 Apple Computer, Inc.
 *
 * Portions are Copyright (C) 2001-6 mozilla.org
 *
 * Other contributors:
 *   Stuart Parmenter <stuart@mozilla.com>
 *
 * Copyright (C) 2007-2009 Torch Mobile, 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; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * 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
 *
 * Alternatively, the contents of this file may be used under the terms
 * of either the Mozilla Public License Version 1.1, found at
 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
 * (the "GPL"), in which case the provisions of the MPL or the GPL are
 * applicable instead of those above.  If you wish to allow use of your
 * version of this file only under the terms of one of those two
 * licenses (the MPL or the GPL) and not to allow others to use your
 * version of this file under the LGPL, indicate your decision by
 * deletingthe provisions above and replace them with the notice and
 * other provisions required by the MPL or the GPL, as the case may be.
 * If you do not delete the provisions above, a recipient may use your
 * version of this file under any of the LGPL, the MPL or the GPL.
 */

#include "config.h"
#include "JPEGImageDecoder.h"
#include <stdio.h>  // Needed by jpeglib.h for FILE.

#if OS(WINCE) || PLATFORM(BREWMP_SIMULATOR)
// Remove warning: 'FAR' macro redefinition
#undef FAR

// jmorecfg.h in libjpeg checks for XMD_H with the comment: "X11/xmd.h correctly defines INT32"
// fix INT32 redefinition error by pretending we are X11/xmd.h
#define XMD_H
#endif

extern "C" {
#include "jpeglib.h"
}

#include <setjmp.h>

namespace WebCore {

struct decoder_error_mgr {
    struct jpeg_error_mgr pub; // "public" fields for IJG library
    jmp_buf setjmp_buffer;     // For handling catastropic errors
};

enum jstate {
    JPEG_HEADER,                 // Reading JFIF headers
    JPEG_START_DECOMPRESS,
    JPEG_DECOMPRESS_PROGRESSIVE, // Output progressive pixels
    JPEG_DECOMPRESS_SEQUENTIAL,  // Output sequential pixels
    JPEG_DONE,
    JPEG_ERROR    
};

void init_source(j_decompress_ptr jd);
boolean fill_input_buffer(j_decompress_ptr jd);
void skip_input_data(j_decompress_ptr jd, long num_bytes);
void term_source(j_decompress_ptr jd);
void error_exit(j_common_ptr cinfo);

// Implementation of a JPEG src object that understands our state machine
struct decoder_source_mgr {
    // public fields; must be first in this struct!
    struct jpeg_source_mgr pub;

    JPEGImageReader* decoder;
};

class JPEGImageReader
{
public:
    JPEGImageReader(JPEGImageDecoder* decoder)
        : m_decoder(decoder)
        , m_bufferLength(0)
        , m_bytesToSkip(0)
        , m_state(JPEG_HEADER)
        , m_samples(0)
    {
        memset(&m_info, 0, sizeof(jpeg_decompress_struct));
 
        // We set up the normal JPEG error routines, then override error_exit.
        m_info.err = jpeg_std_error(&m_err.pub);
        m_err.pub.error_exit = error_exit;

        // Allocate and initialize JPEG decompression object.
        jpeg_create_decompress(&m_info);
  
        decoder_source_mgr* src = 0;
        if (!m_info.src) {
            src = (decoder_source_mgr*)fastCalloc(sizeof(decoder_source_mgr), 1);
            if (!src) {
                m_state = JPEG_ERROR;
                return;
            }
        }

        m_info.src = (jpeg_source_mgr*)src;

        // Set up callback functions.
        src->pub.init_source = init_source;
        src->pub.fill_input_buffer = fill_input_buffer;
        src->pub.skip_input_data = skip_input_data;
        src->pub.resync_to_restart = jpeg_resync_to_restart;
        src->pub.term_source = term_source;
        src->decoder = this;
    }

    ~JPEGImageReader()
    {
        close();
    }

    void close()
    {
        decoder_source_mgr* src = (decoder_source_mgr*)m_info.src;
        if (src)
            fastFree(src);
        m_info.src = 0;

        jpeg_destroy_decompress(&m_info);
    }

    void skipBytes(long numBytes)
    {
        decoder_source_mgr* src = (decoder_source_mgr*)m_info.src;
        long bytesToSkip = std::min(numBytes, (long)src->pub.bytes_in_buffer);
        src->pub.bytes_in_buffer -= (size_t)bytesToSkip;
        src->pub.next_input_byte += bytesToSkip;

        m_bytesToSkip = std::max(numBytes - bytesToSkip, static_cast<long>(0));
    }

    bool decode(const Vector<char>& data, bool onlySize)
    {
        m_decodingSizeOnly = onlySize;

        unsigned newByteCount = data.size() - m_bufferLength;
        unsigned readOffset = m_bufferLength - m_info.src->bytes_in_buffer;

        m_info.src->bytes_in_buffer += newByteCount;
        m_info.src->next_input_byte = (JOCTET*)(data.data()) + readOffset;

        // If we still have bytes to skip, try to skip those now.
        if (m_bytesToSkip)
            skipBytes(m_bytesToSkip);

        m_bufferLength = data.size();
        
        // We need to do the setjmp here. Otherwise bad things will happen
        if (setjmp(m_err.setjmp_buffer)) {
            close();
            return m_decoder->setFailed();
        }

        switch (m_state) {
        case JPEG_HEADER:
            // Read file parameters with jpeg_read_header().
            if (jpeg_read_header(&m_info, true) == JPEG_SUSPENDED)
                return false; // I/O suspension.

            // Let libjpeg take care of gray->RGB and YCbCr->RGB conversions.
            switch (m_info.jpeg_color_space) {
            case JCS_GRAYSCALE:
            case JCS_RGB:
            case JCS_YCbCr:
                m_info.out_color_space = JCS_RGB;
                break;
            case JCS_CMYK:
            case JCS_YCCK:
                // jpeglib cannot convert these to rgb, but it can convert ycck
                // to cmyk.
                m_info.out_color_space = JCS_CMYK;
                break;
            default:
                return m_decoder->setFailed();
            }

            // Don't allocate a giant and superfluous memory buffer when the
            // image is a sequential JPEG.
            m_info.buffered_image = jpeg_has_multiple_scans(&m_info);

            // Used to set up image size so arrays can be allocated.
            jpeg_calc_output_dimensions(&m_info);

            // Make a one-row-high sample array that will go away when done with
            // image. Always make it big enough to hold an RGB row.  Since this
            // uses the IJG memory manager, it must be allocated before the call
            // to jpeg_start_compress().
            m_samples = (*m_info.mem->alloc_sarray)((j_common_ptr) &m_info, JPOOL_IMAGE, m_info.output_width * 4, 1);

            m_state = JPEG_START_DECOMPRESS;

            // We can fill in the size now that the header is available.
            if (!m_decoder->setSize(m_info.image_width, m_info.image_height))
                return m_decoder->setFailed();

            if (m_decodingSizeOnly) {
                // We can stop here.  Reduce our buffer length and available
                // data.
                m_bufferLength -= m_info.src->bytes_in_buffer;
                m_info.src->bytes_in_buffer = 0;
                return true;
            }
        // FALL THROUGH

        case JPEG_START_DECOMPRESS:
            // Set parameters for decompression.
            // FIXME -- Should reset dct_method and dither mode for final pass
            // of progressive JPEG.
            m_info.dct_method =  JDCT_ISLOW;
            m_info.dither_mode = JDITHER_FS;
            m_info.do_fancy_upsampling = true;
            m_info.enable_2pass_quant = false;
            m_info.do_block_smoothing = true;

            // Start decompressor.
            if (!jpeg_start_decompress(&m_info))
                return false; // I/O suspension.

            // If this is a progressive JPEG ...
            m_state = (m_info.buffered_image) ? JPEG_DECOMPRESS_PROGRESSIVE : JPEG_DECOMPRESS_SEQUENTIAL;
        // FALL THROUGH

        case JPEG_DECOMPRESS_SEQUENTIAL:
            if (m_state == JPEG_DECOMPRESS_SEQUENTIAL) {
  
                if (!m_decoder->outputScanlines())
                    return false; // I/O suspension.
  
                // If we've completed image output...
                ASSERT(m_info.output_scanline == m_info.output_height);
                m_state = JPEG_DONE;
            }
        // FALL THROUGH

        case JPEG_DECOMPRESS_PROGRESSIVE:
            if (m_state == JPEG_DECOMPRESS_PROGRESSIVE) {
                int status;
                do {
                    status = jpeg_consume_input(&m_info);
                } while ((status != JPEG_SUSPENDED) && (status != JPEG_REACHED_EOI));

                for (;;) {
                    if (!m_info.output_scanline) {
                        int scan = m_info.input_scan_number;

                        // If we haven't displayed anything yet
                        // (output_scan_number == 0) and we have enough data for
                        // a complete scan, force output of the last full scan.
                        if (!m_info.output_scan_number && (scan > 1) && (status != JPEG_REACHED_EOI))
                            --scan;

                        if (!jpeg_start_output(&m_info, scan))
                            return false; // I/O suspension.
                    }

                    if (m_info.output_scanline == 0xffffff)
                        m_info.output_scanline = 0;

                    if (!m_decoder->outputScanlines()) {
                        if (!m_info.output_scanline)
                            // Didn't manage to read any lines - flag so we
                            // don't call jpeg_start_output() multiple times for
                            // the same scan.
                            m_info.output_scanline = 0xffffff;
                        return false; // I/O suspension.
                    }

                    if (m_info.output_scanline == m_info.output_height) {
                        if (!jpeg_finish_output(&m_info))
                            return false; // I/O suspension.

                        if (jpeg_input_complete(&m_info) && (m_info.input_scan_number == m_info.output_scan_number))
                            break;

                        m_info.output_scanline = 0;
                    }
                }

                m_state = JPEG_DONE;
            }
        // FALL THROUGH

        case JPEG_DONE:
            // Finish decompression.
            return jpeg_finish_decompress(&m_info);
        
        case JPEG_ERROR:
            // We can get here if the constructor failed.
            return m_decoder->setFailed();
        }

        return true;
    }

    jpeg_decompress_struct* info() { return &m_info; }
    JSAMPARRAY samples() const { return m_samples; }
    JPEGImageDecoder* decoder() { return m_decoder; }

private:
    JPEGImageDecoder* m_decoder;
    unsigned m_bufferLength;
    int m_bytesToSkip;
    bool m_decodingSizeOnly;
    bool m_initialized;

    jpeg_decompress_struct m_info;
    decoder_error_mgr m_err;
    jstate m_state;

    JSAMPARRAY m_samples;
};

// Override the standard error method in the IJG JPEG decoder code.
void error_exit(j_common_ptr cinfo)
{
    // Return control to the setjmp point.
    decoder_error_mgr *err = (decoder_error_mgr *) cinfo->err;
    longjmp(err->setjmp_buffer, -1);
}

void init_source(j_decompress_ptr jd)
{
}

void skip_input_data(j_decompress_ptr jd, long num_bytes)
{
    decoder_source_mgr *src = (decoder_source_mgr *)jd->src;
    src->decoder->skipBytes(num_bytes);
}

boolean fill_input_buffer(j_decompress_ptr jd)
{
    // Our decode step always sets things up properly, so if this method is ever
    // called, then we have hit the end of the buffer.  A return value of false
    // indicates that we have no data to supply yet.
    return false;
}

void term_source(j_decompress_ptr jd)
{
    decoder_source_mgr *src = (decoder_source_mgr *)jd->src;
    src->decoder->decoder()->jpegComplete();
}

JPEGImageDecoder::JPEGImageDecoder()
{
}

JPEGImageDecoder::~JPEGImageDecoder()
{
}

bool JPEGImageDecoder::isSizeAvailable()
{
    if (!ImageDecoder::isSizeAvailable())
         decode(true);

    return ImageDecoder::isSizeAvailable();
}

bool JPEGImageDecoder::setSize(unsigned width, unsigned height)
{
    if (!ImageDecoder::setSize(width, height))
        return false;

    prepareScaleDataIfNecessary();
    return true;
}

RGBA32Buffer* JPEGImageDecoder::frameBufferAtIndex(size_t index)
{
    if (index)
        return 0;

    if (m_frameBufferCache.isEmpty())
        m_frameBufferCache.resize(1);

    RGBA32Buffer& frame = m_frameBufferCache[0];
    if (frame.status() != RGBA32Buffer::FrameComplete)
        decode(false);
    return &frame;
}

bool JPEGImageDecoder::outputScanlines()
{
    if (m_frameBufferCache.isEmpty())
        return false;

    // Initialize the framebuffer if needed.
    RGBA32Buffer& buffer = m_frameBufferCache[0];
    if (buffer.status() == RGBA32Buffer::FrameEmpty) {
        if (!buffer.setSize(scaledSize().width(), scaledSize().height()))
            return setFailed();
        buffer.setStatus(RGBA32Buffer::FramePartial);
        buffer.setHasAlpha(false);

        // For JPEGs, the frame always fills the entire image.
        buffer.setRect(IntRect(IntPoint(), size()));
    }

    jpeg_decompress_struct* info = m_reader->info();
    JSAMPARRAY samples = m_reader->samples();

    while (info->output_scanline < info->output_height) {
        // jpeg_read_scanlines will increase the scanline counter, so we
        // save the scanline before calling it.
        int sourceY = info->output_scanline;
        /* Request one scanline.  Returns 0 or 1 scanlines. */
        if (jpeg_read_scanlines(info, samples, 1) != 1)
            return false;

        int destY = scaledY(sourceY);
        if (destY < 0)
            continue;
        int width = m_scaled ? m_scaledColumns.size() : info->output_width;
        for (int x = 0; x < width; ++x) {
            JSAMPLE* jsample = *samples + (m_scaled ? m_scaledColumns[x] : x) * ((info->out_color_space == JCS_RGB) ? 3 : 4);
            if (info->out_color_space == JCS_RGB)
                buffer.setRGBA(x, destY, jsample[0], jsample[1], jsample[2], 0xFF);
            else if (info->out_color_space == JCS_CMYK) {
                // Source is 'Inverted CMYK', output is RGB.
                // See: http://www.easyrgb.com/math.php?MATH=M12#text12
                // Or:  http://www.ilkeratalay.com/colorspacesfaq.php#rgb
                // From CMYK to CMY:
                // X =   X    * (1 -   K   ) +   K  [for X = C, M, or Y]
                // Thus, from Inverted CMYK to CMY is:
                // X = (1-iX) * (1 - (1-iK)) + (1-iK) => 1 - iX*iK
                // From CMY (0..1) to RGB (0..1):
                // R = 1 - C => 1 - (1 - iC*iK) => iC*iK  [G and B similar]
                unsigned k = jsample[3];
                buffer.setRGBA(x, destY, jsample[0] * k / 255, jsample[1] * k / 255, jsample[2] * k / 255, 0xFF);
            } else {
                ASSERT_NOT_REACHED();
                return setFailed();
            }
        }
    }

    return true;
}

void JPEGImageDecoder::jpegComplete()
{
    if (m_frameBufferCache.isEmpty())
        return;

    // Hand back an appropriately sized buffer, even if the image ended up being
    // empty.
    m_frameBufferCache[0].setStatus(RGBA32Buffer::FrameComplete);
}

void JPEGImageDecoder::decode(bool onlySize)
{
    if (failed())
        return;

    if (!m_reader)
        m_reader.set(new JPEGImageReader(this));

    // If we couldn't decode the image but we've received all the data, decoding
    // has failed.
    if (!m_reader->decode(m_data->buffer(), onlySize) && isAllDataReceived())
        setFailed();

    if (failed() || (!m_frameBufferCache.isEmpty() && m_frameBufferCache[0].status() == RGBA32Buffer::FrameComplete))
        m_reader.clear();
}

}