Changeset 52086 in webkit


Ignore:
Timestamp:
Dec 14, 2009 2:48:14 AM (14 years ago)
Author:
zecke@webkit.org
Message:

[Qt] QtWebKit should use QImageReader::setQuality(49)

https://bugs.webkit.org/show_bug.cgi?id=30740

Using QImageReader::setQuality(49) will influence the JPEG
decoder of Qt to use the JDCT_IFAST routines for decompressing. This
is showing a 5% improvement in a reduction that decodes all images
used during the page loading test. The libjpeg documentation mentions
that the IFAST routine is not as accurate as other routines but in
our tests we couldn't see a difference.

  • platform/graphics/qt/ImageDecoderQt.cpp:

(WebCore::ImageDecoderQt::setData):

Location:
trunk/WebCore
Files:
2 edited

Legend:

Unmodified
Added
Removed
  • trunk/WebCore/ChangeLog

    r52085 r52086  
     12009-12-14  Holger Hans Peter Freyther  <zecke@selfish.org>
     2
     3        Rubber-stamped by Simon Hausmann.
     4
     5        [Qt] QtWebKit should use QImageReader::setQuality(49)
     6        https://bugs.webkit.org/show_bug.cgi?id=30740
     7
     8        Using QImageReader::setQuality(49) will influence the JPEG
     9        decoder of Qt to use the JDCT_IFAST routines for decompressing. This
     10        is showing a 5% improvement in a reduction that decodes all images
     11        used during the page loading test. The libjpeg documentation mentions
     12        that the IFAST routine is not as accurate as other routines but in
     13        our tests we couldn't see a difference.
     14
     15        * platform/graphics/qt/ImageDecoderQt.cpp:
     16        (WebCore::ImageDecoderQt::setData):
     17
    1182009-11-11  Philippe Normand  <pnormand@igalia.com>
    219
  • trunk/WebCore/platform/graphics/qt/ImageDecoderQt.cpp

    r51983 r52086  
    8383    m_reader = new QImageReader(m_buffer, m_format);
    8484
     85    // This will force the JPEG decoder to use JDCT_IFAST
     86    m_reader->setQuality(49);
     87
    8588    // QImageReader only allows retrieving the format before reading the image
    8689    m_format = m_reader->format();
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