Comment updates

SDWebImage/SDWebImageGIFCoder.h

@@ -10,7 +10,10 @@
 #import "SDWebImageCoder.h"
 
 /**
- Built in coder that supports GIF
+ Built in coder using ImageIO that supports GIF encoding/decoding
+ @note `SDWebImageIOCoder` supports GIF but only as static (will use the 1st frame).
+ @note Use `SDWebImageGIFCoder` for fully animated GIFs - less performant than `FLAnimatedImage`
+ @note The recommended approach for animated GIFs is using `FLAnimatedImage`
  */
 @interface SDWebImageGIFCoder : NSObject <SDWebImageCoder>
 

SDWebImage/SDWebImageImageIOCoder.h

@@ -11,6 +11,8 @@
 
 /**
  Built in coder that supports PNG, JPEG, TIFF, includes support for progressive decoding
+ Also supports static GIF (meaning will only handle the 1st frame).
+ For a full GIF support, we recommend `FLAnimatedImage` or our less performant `SDWebImageGIFCoder`
  */
 @interface SDWebImageImageIOCoder : NSObject <SDWebImageProgressiveCoder>
 

SDWebImage/SDWebImageImageIOCoder.m

@@ -66,7 +66,7 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
 #pragma mark - Decode
 - (BOOL)canDecodeFromData:(nullable NSData *)data {
     switch ([NSData sd_imageFormatForImageData:data]) {
-        // Do not support GIF and WebP decoding
+        // Do not support WebP decoding
         case SDImageFormatWebP:
             return NO;
         default:
@@ -382,7 +382,7 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
 #pragma mark - Encode
 - (BOOL)canEncodeToFormat:(SDImageFormat)format {
     switch (format) {
-        // Do not support GIF and WebP encoding
+        // Do not support WebP encoding
         case SDImageFormatWebP:
             return NO;
         default: