@@ -43,6 +43,38 @@ static void FreeImageData(void *info, const void *data, size_t size) {
4343 heif_image_release (img); // `heif_image_release` will free the bitmap buffer. We do not call `free`
4444}
4545
46+ // / Calculate the actual thumnail pixel size
47+ static CGSize SDCalculateThumbnailSize (CGSize fullSize, BOOL preserveAspectRatio, CGSize thumbnailSize) {
48+ CGFloat width = fullSize.width ;
49+ CGFloat height = fullSize.height ;
50+ CGFloat resultWidth;
51+ CGFloat resultHeight;
52+
53+ if (width == 0 || height == 0 || thumbnailSize.width == 0 || thumbnailSize.height == 0 || (width <= thumbnailSize.width && height <= thumbnailSize.height )) {
54+ // Full Pixel
55+ resultWidth = width;
56+ resultHeight = height;
57+ } else {
58+ // Thumbnail
59+ if (preserveAspectRatio) {
60+ CGFloat pixelRatio = width / height;
61+ CGFloat thumbnailRatio = thumbnailSize.width / thumbnailSize.height ;
62+ if (pixelRatio > thumbnailRatio) {
63+ resultWidth = thumbnailSize.width ;
64+ resultHeight = ceil (thumbnailSize.width / pixelRatio);
65+ } else {
66+ resultHeight = thumbnailSize.height ;
67+ resultWidth = ceil (thumbnailSize.height * pixelRatio);
68+ }
69+ } else {
70+ resultWidth = thumbnailSize.width ;
71+ resultHeight = thumbnailSize.height ;
72+ }
73+ }
74+
75+ return CGSizeMake (resultWidth, resultHeight);
76+ }
77+
4678@implementation SDImageHEIFCoder
4779
4880+ (instancetype )sharedCoder {
@@ -74,8 +106,24 @@ - (UIImage *)decodedImageWithData:(NSData *)data options:(SDImageCoderOptions *)
74106 }
75107 }
76108
109+ CGSize thumbnailSize = CGSizeZero;
110+ NSValue *thumbnailSizeValue = options[SDImageCoderDecodeThumbnailPixelSize];
111+ if (thumbnailSizeValue != nil ) {
112+ #if SD_MAC
113+ thumbnailSize = thumbnailSizeValue.sizeValue ;
114+ #else
115+ thumbnailSize = thumbnailSizeValue.CGSizeValue ;
116+ #endif
117+ }
118+
119+ BOOL preserveAspectRatio = YES ;
120+ NSNumber *preserveAspectRatioValue = options[SDImageCoderDecodePreserveAspectRatio];
121+ if (preserveAspectRatioValue != nil ) {
122+ preserveAspectRatio = preserveAspectRatioValue.boolValue ;
123+ }
124+
77125 // Currently only support primary image :)
78- CGImageRef imageRef = [self sd_createHEIFImageWithData: data];
126+ CGImageRef imageRef = [self sd_createHEIFImageWithData: data thumbnailSize: thumbnailSize preserveAspectRatio: preserveAspectRatio ];
79127 if (!imageRef) {
80128 return nil ;
81129 }
@@ -91,7 +139,7 @@ - (UIImage *)decodedImageWithData:(NSData *)data options:(SDImageCoderOptions *)
91139}
92140
93141// Only decode the primary image (HEIF also support tied-image and animated image)
94- - (nullable CGImageRef)sd_createHEIFImageWithData : (nonnull NSData *)data CF_RETURNS_RETAINED {
142+ - (nullable CGImageRef)sd_createHEIFImageWithData : (nonnull NSData *)data thumbnailSize : (CGSize) thumbnailSize preserveAspectRatio : ( BOOL ) preserveAspectRatio CF_RETURNS_RETAINED {
95143 heif_context* ctx = heif_context_alloc ();
96144 if (!ctx) {
97145 return nil ;
@@ -113,6 +161,50 @@ - (nullable CGImageRef)sd_createHEIFImageWithData:(nonnull NSData *)data CF_RETU
113161 return nil ;
114162 }
115163
164+ // check thumbnail firstly
165+ if (thumbnailSize.width > 0 && thumbnailSize.height > 0 ) {
166+ heif_item_id thumbnailID;
167+ int thumbnailCount = heif_image_handle_get_list_of_thumbnail_IDs (handle, &thumbnailID, 1 );
168+ if (thumbnailCount > 0 ) {
169+ heif_image_handle *thumbnailHandle;
170+ error = heif_image_handle_get_thumbnail (handle, thumbnailID, &thumbnailHandle);
171+ if (error.code != heif_error_Ok) {
172+ heif_image_handle_release (handle);
173+ heif_context_free (ctx);
174+ return nil ;
175+ }
176+
177+ // use full image to scale down if pixel size is smaller than thumbnail size
178+ int handleWidth = heif_image_handle_get_width (handle);
179+ int handleHeight = heif_image_handle_get_height (handle);
180+ if (handleWidth < thumbnailSize.width && handleHeight < thumbnailSize.height ) {
181+ CGImageRef imageRef = [self sd_createFrameWithImageHandle: thumbnailHandle thumbnailSize: thumbnailSize preserveAspectRatio: preserveAspectRatio];
182+
183+ // clean up
184+ heif_image_handle_release (thumbnailHandle);
185+ heif_image_handle_release (handle);
186+ heif_context_free (ctx);
187+
188+ return imageRef;
189+ } else {
190+ // clean up
191+ heif_image_handle_release (thumbnailHandle);
192+ }
193+ }
194+ }
195+
196+ CGImageRef imageRef = [self sd_createFrameWithImageHandle: handle thumbnailSize: thumbnailSize preserveAspectRatio: preserveAspectRatio];
197+
198+ // clean up
199+ heif_image_handle_release (handle);
200+ heif_context_free (ctx);
201+
202+ return imageRef;
203+ }
204+
205+ - (nullable CGImageRef)sd_createFrameWithImageHandle : (heif_image_handle *)handle thumbnailSize : (CGSize)thumbnailSize preserveAspectRatio : (BOOL )preserveAspectRatio CF_RETURNS_RETAINED {
206+ heif_error error;
207+
116208 // check alpha channel
117209 BOOL hasAlpha = heif_image_handle_has_alpha_channel (handle);
118210 int depth = heif_image_handle_get_chroma_bits_per_pixel (handle);
@@ -136,13 +228,25 @@ - (nullable CGImageRef)sd_createHEIFImageWithData:(nonnull NSData *)data CF_RETU
136228 heif_image* img;
137229 error = heif_decode_image (handle, &img, heif_colorspace_RGB, chroma, NULL );
138230 if (error.code != heif_error_Ok) {
139- heif_image_handle_release (handle);
140- heif_context_free (ctx);
141231 return nil ;
142232 }
143233
234+ int handleWidth = heif_image_handle_get_width (handle);
235+ int handleHeight = heif_image_handle_get_height (handle);
236+ CGSize scaledSize = SDCalculateThumbnailSize (CGSizeMake (handleWidth, handleHeight), preserveAspectRatio, thumbnailSize);
237+ // use scaling for thumbnail
238+ if (scaledSize.width > 0 && scaledSize.height > 0 && scaledSize.width != handleWidth && scaledSize.height != handleHeight) {
239+ heif_image *scaled_img;
240+ error = heif_image_scale_image (img, &scaled_img, scaledSize.width , scaledSize.height , NULL );
241+ heif_image_release (img);
242+ if (error.code != heif_error_Ok) {
243+ return nil ;
244+ }
245+ img = scaled_img;
246+ }
247+
144248 int width, height, stride, bitsPerPixel, bitsPerComponent;
145- width = heif_image_get_width (img, heif_channel_interleaved);
249+ width = heif_image_get_width (img, heif_channel_interleaved);
146250 height = heif_image_get_height (img, heif_channel_interleaved);
147251 bitsPerPixel = heif_image_get_bits_per_pixel (img, heif_channel_interleaved);
148252 bitsPerComponent = hasHighDepth ? 16 : 8 ;
@@ -152,8 +256,6 @@ - (nullable CGImageRef)sd_createHEIFImageWithData:(nonnull NSData *)data CF_RETU
152256 const uint8_t *rgba = heif_image_get_plane_readonly (img, heif_channel_interleaved, &stride);
153257 if (!rgba) {
154258 heif_image_release (img);
155- heif_image_handle_release (handle);
156- heif_context_free (ctx);
157259 return nil ;
158260 }
159261 CGDataProviderRef provider =
@@ -165,8 +267,6 @@ - (nullable CGImageRef)sd_createHEIFImageWithData:(nonnull NSData *)data CF_RETU
165267
166268 // clean up
167269 CGDataProviderRelease (provider);
168- heif_image_handle_release (handle);
169- heif_context_free (ctx);
170270
171271 return imageRef;
172272}
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