inable to decode jpg images using skia on android

[swagat mishra]

hi,
i have set up skia on android (api 15).
I am trying to decode a jpg image using the following code:
SkBitmap bitmap;
SkStream* stream = new SkFILEStream("testfile.jpg");
bool x = SkImageDecoder::DecodeFile("testfile.jpg", &bitmap);

however, skia is unable to decode the file and returns false for x. the same code works while decoding png or bmp files.
Is this a known bug for skia in android? is there any workaroudn for this issue?
Regards,
Swagat Mishra

[Robert Phillips]

Hi There,
Have you tried adding a call to force linking of the jpeg codec? The
cmykjpeg.cpp file has an example of how this is done. PNGs are handled
special by Android by defining the SK_ENABLE_LIBPNG in
SkImageDecoderFactory.cpp.

Rob

On Sat, Aug 4, 2012 at 1:17 PM, swagat mishra
<swagatmi...@gmail.com> wrote:
> waiting for replies on this...please help

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[swagat mishra]

Hi,

I did the force linking and while debugging find that the right codec is being used and am able to step in to SkImageDecoder_libjpeg.cpp.

However , i am still unable to get a decoded jpeg.

Does this mean its a problem in libjpeg and not skia?

As an additional information ,
i stepped into libjpeg and went till jddctmgr.c and found that JDCT_IFAST_SUPPORTED is not defined and i think this could be a cause of the failing.

 

 

[Jon C]

I ran into the same problem, and it turns out that libjpeg by default (in jmorecfg.h) only defines DCT_ISLOW_SUPPORTED, and undef's DCT_IFAST* or DCT_FLOAT*.  However, in Skia, for SkImageDecoder_libjpeg.cpp, it sets cinfo.dct_method = JDCT_IFAST by default.  This is why currently, out of the box, it doesn't look like skia would be able to decode jpeg.  Setting cinfo.dct_method = JDCT_ISLOW (or presumably defining IFAST_SUPPORTED or FLOAT_SUPPORTED in jmorecfg.h) allowed it to work for me.

[Anthony Catel]

Same issue here.

The annoying thing is that DCT_I* macro are wrapper in JPEG_INTERNAL_OPTIONS which make skia impossible to #ifdef for the good value.

Setting it to ISLOW on SkImageDecode_libjpeg.cpp would be right choice IMHO.

[Janez Zemva]

Just use something else, I recommend:

http://nothings.org/stb_image.c

2012/9/28 Anthony Catel <a.c...@weelya.com>:

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