update webp to 1.2.0

deps/webp/include/webp/decode.h

@@ -453,7 +453,7 @@ struct WebPDecoderOptions {
   int scaled_width, scaled_height;    // final resolution
   int use_threads;                    // if true, use multi-threaded decoding
   int dithering_strength;             // dithering strength (0=Off, 100=full)
-  int flip;                           // flip output vertically
+  int flip;                           // if true, flip output vertically
   int alpha_dithering_strength;       // alpha dithering strength in [0..100]
 
   uint32_t pad[5];                    // padding for later use

deps/webp/include/webp/encode.h

@@ -148,7 +148,8 @@ struct WebPConfig {
   int use_delta_palette;  // reserved for future lossless feature
   int use_sharp_yuv;      // if needed, use sharp (and slow) RGB->YUV conversion
 
-  uint32_t pad[2];        // padding for later use
+  int qmin;               // minimum permissible quality factor
+  int qmax;               // maximum permissible quality factor
 };
 
 // Enumerate some predefined settings for WebPConfig, depending on the type
@@ -291,6 +292,11 @@ typedef enum WebPEncodingError {
 #define WEBP_MAX_DIMENSION 16383
 
 // Main exchange structure (input samples, output bytes, statistics)
+//
+// Once WebPPictureInit() has been called, it's ok to make all the INPUT fields
+// (use_argb, y/u/v, argb, ...) point to user-owned data, even if
+// WebPPictureAlloc() has been called. Depending on the value use_argb,
+// it's guaranteed that either *argb or *y/*u/*v content will be kept untouched.
 struct WebPPicture {
   //   INPUT
   //////////////

deps/webp/lib/pkgconfig/libwebp.pc

@@ -1,11 +1,11 @@
 prefix=
 exec_prefix=${prefix}
-libdir=${prefix}/lib
+libdir=${exec_prefix}/lib
 includedir=${prefix}/include
 
 Name: libwebp
 Description: Library for the WebP graphics format
-Version: 1.1.0
+Version: 1.2.0
 Cflags: -I${prefix}/include
 Libs: -L${prefix}/lib -lwebp
 Libs.private: