darling-cocotron/Onyx2D/O2ImageSource_JPEG.m

/* Copyright (c) 2007 Christopher J. W. Lloyd

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */

#import <Foundation/NSData.h>
#import <Foundation/NSString.h>
#import <Onyx2D/O2ColorSpace.h>
#import <Onyx2D/O2DataProvider.h>
#import <Onyx2D/O2Image.h>
#import <Onyx2D/O2ImageSource_JPEG.h>
#import <Onyx2D/O2ImageSource_TIFF.h>

#import <Onyx2D/O2Defines_libjpeg.h>

#ifdef LIBJPEG_PRESENT
#import <Onyx2D/O2ImageDecoder_JPEG_libjpeg.h>
#else
#import <Onyx2D/O2ImageDecoder_JPEG_stb.h>
#endif

#import <Onyx2D/O2EXIFDecoder.h>

#import <assert.h>
#import <string.h>

@implementation O2ImageSource_JPEG

static O2ImageDecoder *
createImageDecoderWithDataProvider(O2DataProviderRef dataProvider)
{
#ifdef LIBJPEG_PRESENT
    return [[O2ImageDecoder_JPEG_libjpeg alloc]
            initWithDataProvider: dataProvider];
#else
    return [[O2ImageDecoder_JPEG_stb alloc] initWithDataProvider: dataProvider];
#endif
}

NSData *O2DCTDecode(NSData *data, size_t *pBytesPerRow) {
    O2DataProviderRef dataProvider =
            O2DataProviderCreateWithCFData((CFDataRef) data);
    O2ImageDecoderRef decoder =
            createImageDecoderWithDataProvider(dataProvider);
    CFDataRef result = O2ImageDecoderCreatePixelData(decoder);

    if (pBytesPerRow != NULL) {
        *pBytesPerRow = O2ImageDecoderGetBytesPerRow(decoder);
    }

    [decoder release];
    O2DataProviderRelease(dataProvider);

    return (NSData *) result;
}

+ (BOOL) isPresentInDataProvider: (O2DataProvider *) provider {
    enum { signatureLength = 2 };
    unsigned char signature[signatureLength] = {0xFF, 0xD8};
    unsigned char check[signatureLength];
    NSInteger i, size = [provider getBytes: check
                                     range: NSMakeRange(0, signatureLength)];

    if (size != signatureLength)
        return NO;

    for (i = 0; i < signatureLength; i++)
        if (signature[i] != check[i])
            return NO;

    return YES;
}

- initWithDataProvider: (O2DataProviderRef) provider
               options: (NSDictionary *) options
{
    [super initWithDataProvider: provider options: options];
    return self;
}

- (void) dealloc {
    if (_jpg)
        CFRelease(_jpg);
    [super dealloc];
}

- (CFStringRef) type {
    return (CFStringRef) @"public.jpeg";
}

- (NSUInteger) count {
    return 1;
}

- (CFDictionaryRef) copyPropertiesAtIndex: (NSUInteger) idx
                                  options: (CFDictionaryRef) options
{
    if (_jpg == NULL) {
        _jpg = O2DataProviderCopyData(_provider);
    }
    const unsigned char *data = CFDataGetBytePtr(_jpg);
    unsigned long length = CFDataGetLength(_jpg);
    O2EXIFDecoder *exif =
            [[[O2EXIFDecoder alloc] initWithBytes: data
                                           length: length] autorelease];
    return (CFDictionaryRef)[[exif tags] copy];
}

- (O2ImageRef) createImageAtIndex: (NSUInteger) index
                          options: (CFDictionaryRef) options
{
    O2ImageDecoderRef decoder = createImageDecoderWithDataProvider(_provider);
    O2DataProviderRef provider = O2ImageDecoderCreatePixelDataProvider(decoder);

    O2Image *image = [[O2Image alloc]
               initWithWidth: O2ImageDecoderGetWidth(decoder)
                      height: O2ImageDecoderGetHeight(decoder)
            bitsPerComponent: O2ImageDecoderGetBitsPerComponent(decoder)
                bitsPerPixel: O2ImageDecoderGetBitsPerPixel(decoder)
                 bytesPerRow: O2ImageDecoderGetBytesPerRow(decoder)
                  colorSpace: O2ImageDecoderGetColorSpace(decoder)
                  bitmapInfo: O2ImageDecoderGetBitmapInfo(decoder)
                     decoder: decoder
                    provider: provider
                      decode: NULL
                 interpolate: NO
             renderingIntent: kO2RenderingIntentDefault];

    O2DataProviderRelease(provider);
    [decoder release];

    return image;
}

@end