libwebp-1.3.1

- 6/23/2023: version 1.3.1
   This is a binary compatible release.
   * security fixes for lossless encoder (#603, chromium: #1420107, #1455619,
     CVE-2023-1999)
   * improve error reporting through WebPPicture error codes
   * fix upsampling for RGB565 and RGBA4444 in NEON builds
   * img2webp: add -sharp_yuv & -near_lossless
   * Windows builds:
     - fix compatibility with clang-cl (#607)
     - improve Arm64 performance with cl.exe
     - add Arm64EC support
   * fix webp_js with emcc >= 3.1.27 (stack size change, #614)
   * CMake fixes (#592, #610, #612)
   * further updates to the container and lossless bitstream docs (#581, #611)
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEaw5rcJdt4wPt8vYB+cPWvbgjK10FAmSc53oACgkQ+cPWvbgj
 K120Fg//f0JkK3oKnO8P4B5XSAK26/5845xBPU8D06UuUqhct+mjfF5kM1CFxxex
 49W4rT7RJCpgGlwmRFFgRB3a9j7cW4C+Kt5MAfM++vudVrxnpnX6o3rdVDQ60PEZ
 C4T5u2jio/HuZAkPWYwwmIAz1vfqTjYpi0D12hn7yoBoketGcISlMuTgmwfjyQKg
 bn3JcjcjKtERfXSH36aCtnGAXJdf0Ok2WJtwS4kAcZiMByi5wf0AdEK0pnhmE3Y6
 YFPc0/RM50RXITnsDxmLZVRqpsAYr4l3RZvHwDDWVFMELWBsGWNF/kgzWlZ3/KjO
 4CUPE+810P4oVGJuRZ8++0hMSD0L1qh17awElpqLoBlDXfS1fEIw5QodbmoJzi0H
 mhiLH7fIZlpjoZyWuwNCzlkhykRLO4cEIaxxq28p5eoC70LXsv77rWqomfAja/6/
 88BQz6wrxHr0k4MmdOa+G8B5sMOBRVXXeW4bP1XCVGUfk8FN2rz0vlhbHk8sx/6/
 jqW19Bk3t2QnUZschBi1GKHKa0KkefFhTezTm/CV4fPmT50Z4k/+TTjJ6snSxAAX
 oYabJDtVARLgPxOcN64Hbsy1t5L9pWGLTfwbYBTVipX4lmofL9SHhgyg6oYVnZd5
 qbCVdqpYOOrbXXT/AByOuzo3tuaLMd8Ytas0I5/HHnI6QCTthg0=
 =/atT
 -----END PGP SIGNATURE-----

Merge tag 'v1.3.1'

libwebp-1.3.1

- 6/23/2023: version 1.3.1
  This is a binary compatible release.
  * security fixes for lossless encoder (#603, chromium: #1420107, #1455619,
    CVE-2023-1999)
  * improve error reporting through WebPPicture error codes
  * fix upsampling for RGB565 and RGBA4444 in NEON builds
  * img2webp: add -sharp_yuv & -near_lossless
  * Windows builds:
    - fix compatibility with clang-cl (#607)
    - improve Arm64 performance with cl.exe
    - add Arm64EC support
  * fix webp_js with emcc >= 3.1.27 (stack size change, #614)
  * CMake fixes (#592, #610, #612)
  * further updates to the container and lossless bitstream docs (#581, #611)

* tag 'v1.3.1':
  update ChangeLog
  update NEWS
  enc/*: normalize WebPEncodingSetError() calls
  enc/*: add missing WebPEncodingSetError() calls
  EncodeAlphaInternal: add missing error check
  vp8l_enc,WriteImage: add missing error check
  muxread,MuxImageParse: add missing error checks
  cmake,emscripten: explicitly set stack size
  WebPDecodeYUV: check u/v/stride/uv_stride ptrs
  Call png_get_channels() to see if image has alpha
  update ChangeLog
  update NEWS
  bump version to 1.3.1
  update AUTHORS
  update .mailmap

Bug: webp:608
Bug: b/281615350
Change-Id: Ic3e1956c92fef0ae22040bbc3e81b297c65008af

.mailmap

@@ -16,3 +16,4 @@ James Zern <jzern@google.com>
 Roberto Alanis <alanisbaez@google.com>
 Brian Ledger <brianpl@google.com>
 Maryla Ustarroz-Calonge <maryla@google.com>
+Yannis Guyon <yguyon@google.com>

AUTHORS

@@ -32,6 +32,7 @@ Contributors:
 - Mislav Bradac (mislavm at google dot com)
 - Nico Weber (thakis at chromium dot org)
 - Noel Chromium (noel at chromium dot org)
+- Nozomi Isozaki (nontan at pixiv dot co dot jp)
 - Oliver Wolff (oliver dot wolff at qt dot io)
 - Owen Rodley (orodley at google dot com)
 - Parag Salasakar (img dot mips1 at gmail dot com)
@@ -47,6 +48,7 @@ Contributors:
 - Somnath Banerjee (somnath dot banerjee at gmail dot com)
 - Sriraman Tallam (tmsriram at google dot com)
 - Tamar Levy (tamar dot levy at intel dot com)
+- Thiago Perrotta (tperrotta at google dot com)
 - Timothy Gu (timothygu99 at gmail dot com)
 - Urvang Joshi (urvang at google dot com)
 - Vikas Arora (vikasa at google dot com)

CMakeLists.txt

@@ -651,6 +651,16 @@ if(WEBP_BUILD_EXTRAS)
 endif()
 
 if(WEBP_BUILD_WEBP_JS)
+  # The default stack size changed from 5MB to 64KB in 3.1.27. See
+  # https://crbug.com/webp/614.
+  if(EMSCRIPTEN_VERSION VERSION_GREATER_EQUAL "3.1.27")
+    # TOTAL_STACK size was renamed to STACK_SIZE in 3.1.27. The old name was
+    # kept for compatibility, but prefer the new one in case it is removed in
+    # the future.
+    set(emscripten_stack_size "-sSTACK_SIZE=5MB")
+  else()
+    set(emscripten_stack_size "-sTOTAL_STACK=5MB")
+  endif()
   # wasm2js does not support SIMD.
   if(NOT WEBP_ENABLE_SIMD)
     # JavaScript version
@@ -660,7 +670,7 @@ if(WEBP_BUILD_WEBP_JS)
     set(WEBP_HAVE_SDL 1)
     set_target_properties(
       webp_js
-      PROPERTIES LINK_FLAGS "-sWASM=0 \
+      PROPERTIES LINK_FLAGS "-sWASM=0 ${emscripten_stack_size} \
          -sEXPORTED_FUNCTIONS=_WebPToSDL -sINVOKE_RUN=0 \
          -sEXPORTED_RUNTIME_METHODS=cwrap")
     set_target_properties(webp_js PROPERTIES OUTPUT_NAME webp)
@@ -673,7 +683,7 @@ if(WEBP_BUILD_WEBP_JS)
   target_include_directories(webp_wasm PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
   set_target_properties(
     webp_wasm
-    PROPERTIES LINK_FLAGS "-sWASM=1 \
+    PROPERTIES LINK_FLAGS "-sWASM=1 ${emscripten_stack_size} \
        -sEXPORTED_FUNCTIONS=_WebPToSDL -sINVOKE_RUN=0 \
        -sEXPORTED_RUNTIME_METHODS=cwrap")
   target_compile_definitions(webp_wasm PUBLIC EMSCRIPTEN WEBP_HAVE_SDL)

ChangeLog

@@ -1,3 +1,78 @@
+e1adea50 update NEWS
+43393320 enc/*: normalize WebPEncodingSetError() calls
+287fdefe enc/*: add missing WebPEncodingSetError() calls
+c3bd7cff EncodeAlphaInternal: add missing error check
+d49cfbb3 vp8l_enc,WriteImage: add missing error check
+2e5a9ec3 muxread,MuxImageParse: add missing error checks
+ebb6f949 cmake,emscripten: explicitly set stack size
+59a2b1f9 WebPDecodeYUV: check u/v/stride/uv_stride ptrs
+8e965ccb Call png_get_channels() to see if image has alpha
+7f0a3419 update ChangeLog (tag: v1.3.1-rc1)
+bab7efbe update NEWS
+7138bf8f bump version to 1.3.1
+435b4ded update AUTHORS
+47351229 update .mailmap
+ff6c7f4e CONTRIBUTING.md: add C style / cmake-format notes
+dd530437 add .cmake-format.py
+adbe2cb1 cmake,cosmetics: apply cmake-format
+15b36508 doc/webp-container-spec: rm future codec comment
+c369c4bf doc/webp-lossless-bitstream-spec: improve link text
+1de35f47 doc/webp-container-spec: don't use 'currently'
+bb06a16e doc/webp-container-spec: prefer present tense
+9f38b71e doc/webp-lossless-bitstream-spec: prefer present tense
+7acb6b82 doc/webp-container-spec: avoid i.e. & e.g.
+4967e7cd doc/webp-lossless-bitstream-spec: avoid i.e. & e.g.
+e3366659 Merge "Do not find_package image libraries if not needed." into main
+428588ef clarify single leaf node trees and use of canonical prefix coding
+709ec152 Do not find_package image libraries if not needed.
+8dd80ef8 fuzz_utils.h: lower kFuzzPxLimit w/ASan
+8f187b9f Clean message calls in CMake
+cba30078 WebPConfig.cmake.in: use calculated include path
+6cf9a76a Merge "webp-lossless-bitstream-spec: remove use of 'dynamics'" into main
+740943b2 Merge "Specialize and optimize ITransform_SSE2 using do_two" into main
+2d547e24 Compare kFuzzPxLimit to max_num_operations
+ac42dde1 Specialize and optimize ITransform_SSE2 using do_two
+17e0ef1d webp-lossless-bitstream-spec: remove use of 'dynamics'
+ed274371 neon.h,cosmetics: clear a couple lint warnings
+3fb82947 cpu.h,cosmetics: segment defines
+0c496a4f cpu.h: add WEBP_AARCH64
+8151f388 move VP8GetCPUInfo declaration to cpu.c
+916548c2 Make kFuzzPxLimit sanitizer dependent
+4070b271 advanced_api_fuzzer: reduce scaling limit
+761f49c3 Merge "webp-lossless-bitstream-spec: add missing bits to ABNF" into main
+84d04c48 webp-lossless-bitstream-spec: add missing bits to ABNF
+0696e1a7 advanced_api_fuzzer: reduce scaling limit
+93d88aa2 Merge "deps.cmake: remove unneeded header checks" into main
+118e0035 deps.cmake: remove unneeded header checks
+4c3d7018 webp-lossless-bitstream-spec: condense normal-prefix-code
+a6a09b32 webp-lossless-bitstream-spec: fix 2 code typos
+50ac4f7c Merge "cpu.h: enable NEON w/_M_ARM64EC" into main
+4b7d7b4f Add contribution instructions
+0afbd97b cpu.h: enable NEON w/_M_ARM64EC
+349f4353 Merge changes Ibd89e56b,Ic57e7f84,I89096614 into main
+8f7513b7 upsampling_neon.c: fix WEBP_SWAP_16BIT_CSP check
+cbf624b5 advanced_api_fuzzer: reduce scaling limit
+89edfdd1 Skip slow scaling in libwebp advanced_api_fuzzer
+859f19f7 Reduce libwebp advanced_api_fuzzer threshold
+a4f04835 Merge changes Ic389aaa2,I329ccd79 into main
+1275fac8 Makefile.vc: fix img2webp link w/dynamic cfg
+2fe27bb9 img2webp: normalize help output
+24bed3d9 cwebp: reflow -near_lossless help text
+0825faa4 img2webp: add -sharp_yuv/-near_lossless
+d64e6d7d Merge "PaletteSortModifiedZeng: fix leak on error" into main
+0e12a22d Merge "EncodeAlphaInternal: clear result->bw on error" into main
+0edbb6ea PaletteSortModifiedZeng: fix leak on error
+41ffe04e Merge "Update yapf style from "chromium" to "yapf"" into main
+2d9d9265 Update yapf style from "chromium" to "yapf"
+a486d800 EncodeAlphaInternal: clear result->bw on error
+1347a32d Skip big scaled advanced_api_fuzzer
+52b6f067 Fix scaling limit in advanced_api_fuzzer.c
+73618428 Limit scaling in libwebp advanced_api_fuzzer.c
+b54d21a0 Merge "CMakeLists.txt: allow CMAKE_INSTALL_RPATH to be set empty" into main
+31c28db5 libwebp{,demux,mux}.pc.in: Requires -> Requires.private
+d9a505ff CMakeLists.txt: allow CMAKE_INSTALL_RPATH to be set empty
+bdf33d03 Merge tag 'v1.3.0'
+b5577769 update ChangeLog (tag: v1.3.0-rc1, tag: v1.3.0)
 0ba77244 update NEWS
 e763eb1e bump version to 1.3.0
 2a8686fc update AUTHORS
@@ -103,7 +178,7 @@ c626e7d5 cwebp: fix WebPPictureHasTransparency call
 866e349c Merge tag 'v1.2.4'
 c170df38 Merge "Create libsharpyuv.a in makefile.unix." into main
 9d7ff74a Create libsharpyuv.a in makefile.unix.
-0d1f1254 update ChangeLog (tag: v1.2.4, origin/1.2.4)
+0d1f1254 update ChangeLog (tag: v1.2.4)
 fcbc2d78 Merge "doc/*.txt: restrict code to 69 columns" into main
 4ad0e189 Merge "webp-container-spec.txt: normalize fourcc spelling" into main
 980d2488 update NEWS

NEWS

@@ -1,3 +1,18 @@
+- 6/23/2023: version 1.3.1
+  This is a binary compatible release.
+  * security fixes for lossless encoder (#603, chromium: #1420107, #1455619,
+    CVE-2023-1999)
+  * improve error reporting through WebPPicture error codes
+  * fix upsampling for RGB565 and RGBA4444 in NEON builds
+  * img2webp: add -sharp_yuv & -near_lossless
+  * Windows builds:
+    - fix compatibility with clang-cl (#607)
+    - improve Arm64 performance with cl.exe
+    - add Arm64EC support
+  * fix webp_js with emcc >= 3.1.27 (stack size change, #614)
+  * CMake fixes (#592, #610, #612)
+  * further updates to the container and lossless bitstream docs (#581, #611)
+
 - 12/16/2022: version 1.3.0
   This is a binary compatible release.
   * add libsharpyuv, which exposes -sharp_yuv/config.use_sharp_yuv

README.md

@@ -7,7 +7,7 @@
       \__\__/\____/\_____/__/ ____  ___
             / _/ /    \    \ /  _ \/ _/
            /  \_/   / /   \ \   __/  \__
-           \____/____/\_____/_____/____/v1.3.0
+           \____/____/\_____/_____/____/v1.3.1
 ```
 
 WebP codec is a library to encode and decode images in WebP format. This package

configure.ac

@@ -1,4 +1,4 @@
-AC_INIT([libwebp], [1.3.0],
+AC_INIT([libwebp], [1.3.1],
         [https://bugs.chromium.org/p/webp],,
         [https://developers.google.com/speed/webp])
 AC_CANONICAL_HOST

extras/extras.c

@@ -19,7 +19,7 @@
 
 #define XTRA_MAJ_VERSION 1
 #define XTRA_MIN_VERSION 3
-#define XTRA_REV_VERSION 0
+#define XTRA_REV_VERSION 1
 
 //------------------------------------------------------------------------------
 

imageio/pngdec.c

@@ -235,7 +235,7 @@ int ReadPNG(const uint8_t* const data, size_t data_size,
   volatile png_infop end_info = NULL;
   PNGReadContext context = { NULL, 0, 0 };
   int color_type, bit_depth, interlaced;
-  int has_alpha;
+  int num_channels;
   int num_passes;
   int p;
   volatile int ok = 0;
@@ -293,9 +293,6 @@ int ReadPNG(const uint8_t* const data, size_t data_size,
   }
   if (png_get_valid(png, info, PNG_INFO_tRNS)) {
     png_set_tRNS_to_alpha(png);
-    has_alpha = 1;
-  } else {
-    has_alpha = !!(color_type & PNG_COLOR_MASK_ALPHA);
   }
 
   // Apply gamma correction if needed.
@@ -310,13 +307,16 @@ int ReadPNG(const uint8_t* const data, size_t data_size,
 
   if (!keep_alpha) {
     png_set_strip_alpha(png);
-    has_alpha = 0;
   }
 
   num_passes = png_set_interlace_handling(png);
   png_read_update_info(png, info);
 
-  stride = (int64_t)(has_alpha ? 4 : 3) * width * sizeof(*rgb);
+  num_channels = png_get_channels(png, info);
+  if (num_channels != 3 && num_channels != 4) {
+    goto Error;
+  }
+  stride = (int64_t)num_channels * width * sizeof(*rgb);
   if (stride != (int)stride ||
       !ImgIoUtilCheckSizeArgumentsOverflow(stride, height)) {
     goto Error;
@@ -341,8 +341,8 @@ int ReadPNG(const uint8_t* const data, size_t data_size,
 
   pic->width = (int)width;
   pic->height = (int)height;
-  ok = has_alpha ? WebPPictureImportRGBA(pic, rgb, (int)stride)
+  ok = (num_channels == 4) ? WebPPictureImportRGBA(pic, rgb, (int)stride)
-                 : WebPPictureImportRGB(pic, rgb, (int)stride);
+                           : WebPPictureImportRGB(pic, rgb, (int)stride);
 
   if (!ok) {
     goto Error;

sharpyuv/Makefile.am

@@ -33,7 +33,7 @@ libsharpyuv_la_SOURCES += sharpyuv_gamma.c sharpyuv_gamma.h
 libsharpyuv_la_SOURCES += sharpyuv.c sharpyuv.h
 
 libsharpyuv_la_CPPFLAGS = $(AM_CPPFLAGS)
-libsharpyuv_la_LDFLAGS = -no-undefined -version-info 0:0:0 -lm
+libsharpyuv_la_LDFLAGS = -no-undefined -version-info 0:1:0 -lm
 libsharpyuv_la_LIBADD =
 libsharpyuv_la_LIBADD += libsharpyuv_sse2.la
 libsharpyuv_la_LIBADD += libsharpyuv_neon.la

sharpyuv/libsharpyuv.rc

@@ -6,8 +6,8 @@
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 0,0,2,0
+ FILEVERSION 0,0,2,1
- PRODUCTVERSION 0,0,2,0
+ PRODUCTVERSION 0,0,2,1
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -24,12 +24,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Google, Inc."
             VALUE "FileDescription", "libsharpyuv DLL"
-            VALUE "FileVersion", "0.2.0"
+            VALUE "FileVersion", "0.2.1"
             VALUE "InternalName", "libsharpyuv.dll"
-            VALUE "LegalCopyright", "Copyright (C) 2022"
+            VALUE "LegalCopyright", "Copyright (C) 2023"
             VALUE "OriginalFilename", "libsharpyuv.dll"
             VALUE "ProductName", "SharpYuv Library"
-            VALUE "ProductVersion", "0.2.0"
+            VALUE "ProductVersion", "0.2.1"
         END
     END
     BLOCK "VarFileInfo"

src/Makefile.am

@@ -36,7 +36,7 @@ libwebp_la_LIBADD += utils/libwebputils.la
 # other than the ones listed on the command line, i.e., after linking, it will
 # not have unresolved symbols. Some platforms (Windows among them) require all
 # symbols in shared libraries to be resolved at library creation.
-libwebp_la_LDFLAGS = -no-undefined -version-info 8:6:1
+libwebp_la_LDFLAGS = -no-undefined -version-info 8:7:1
 libwebpincludedir = $(includedir)/webp
 pkgconfig_DATA = libwebp.pc
 
@@ -48,7 +48,7 @@ if BUILD_LIBWEBPDECODER
   libwebpdecoder_la_LIBADD += dsp/libwebpdspdecode.la
   libwebpdecoder_la_LIBADD += utils/libwebputilsdecode.la
 
-  libwebpdecoder_la_LDFLAGS = -no-undefined -version-info 4:6:1
+  libwebpdecoder_la_LDFLAGS = -no-undefined -version-info 4:7:1
   pkgconfig_DATA += libwebpdecoder.pc
 endif
 

src/dec/vp8i_dec.h

@@ -32,7 +32,7 @@ extern "C" {
 // version numbers
 #define DEC_MAJ_VERSION 1
 #define DEC_MIN_VERSION 3
-#define DEC_REV_VERSION 0
+#define DEC_REV_VERSION 1
 
 // YUV-cache parameters. Cache is 32-bytes wide (= one cacheline).
 // Constraints are: We need to store one 16x16 block of luma samples (y),

src/dec/webp_dec.c

@@ -658,19 +658,26 @@ uint8_t* WebPDecodeBGRA(const uint8_t* data, size_t data_size,
 uint8_t* WebPDecodeYUV(const uint8_t* data, size_t data_size,
                        int* width, int* height, uint8_t** u, uint8_t** v,
                        int* stride, int* uv_stride) {
-  WebPDecBuffer output;   // only to preserve the side-infos
+  // data, width and height are checked by Decode().
-  uint8_t* const out = Decode(MODE_YUV, data, data_size,
+  if (u == NULL || v == NULL || stride == NULL || uv_stride == NULL) {
-                              width, height, &output);
+    return NULL;
-
+  }
-  if (out != NULL) {
+
-    const WebPYUVABuffer* const buf = &output.u.YUVA;
+  {
-    *u = buf->u;
+    WebPDecBuffer output;   // only to preserve the side-infos
-    *v = buf->v;
+    uint8_t* const out = Decode(MODE_YUV, data, data_size,
-    *stride = buf->y_stride;
+                                width, height, &output);
-    *uv_stride = buf->u_stride;
+
-    assert(buf->u_stride == buf->v_stride);
+    if (out != NULL) {
+      const WebPYUVABuffer* const buf = &output.u.YUVA;
+      *u = buf->u;
+      *v = buf->v;
+      *stride = buf->y_stride;
+      *uv_stride = buf->u_stride;
+      assert(buf->u_stride == buf->v_stride);
+    }
+    return out;
   }
-  return out;
 }
 
 static void DefaultFeatures(WebPBitstreamFeatures* const features) {

src/demux/Makefile.am

@@ -13,6 +13,6 @@ noinst_HEADERS =
 noinst_HEADERS += ../webp/format_constants.h
 
 libwebpdemux_la_LIBADD = ../libwebp.la
-libwebpdemux_la_LDFLAGS = -no-undefined -version-info 2:12:0
+libwebpdemux_la_LDFLAGS = -no-undefined -version-info 2:13:0
 libwebpdemuxincludedir = $(includedir)/webp
 pkgconfig_DATA = libwebpdemux.pc

src/demux/demux.c

@@ -25,7 +25,7 @@
 
 #define DMUX_MAJ_VERSION 1
 #define DMUX_MIN_VERSION 3
-#define DMUX_REV_VERSION 0
+#define DMUX_REV_VERSION 1
 
 typedef struct {
   size_t start_;        // start location of the data

src/demux/libwebpdemux.rc

@@ -6,8 +6,8 @@
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 1,0,3,0
+ FILEVERSION 1,0,3,1
- PRODUCTVERSION 1,0,3,0
+ PRODUCTVERSION 1,0,3,1
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -24,12 +24,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Google, Inc."
             VALUE "FileDescription", "libwebpdemux DLL"
-            VALUE "FileVersion", "1.3.0"
+            VALUE "FileVersion", "1.3.1"
             VALUE "InternalName", "libwebpdemux.dll"
-            VALUE "LegalCopyright", "Copyright (C) 2022"
+            VALUE "LegalCopyright", "Copyright (C) 2023"
             VALUE "OriginalFilename", "libwebpdemux.dll"
             VALUE "ProductName", "WebP Image Demuxer"
-            VALUE "ProductVersion", "1.3.0"
+            VALUE "ProductVersion", "1.3.1"
         END
     END
     BLOCK "VarFileInfo"

src/enc/alpha_enc.c

@@ -141,6 +141,11 @@ static int EncodeAlphaInternal(const uint8_t* const data, int width, int height,
                               !reduce_levels, &tmp_bw, &result->stats);
     if (ok) {
       output = VP8LBitWriterFinish(&tmp_bw);
+      if (tmp_bw.error_) {
+        VP8LBitWriterWipeOut(&tmp_bw);
+        memset(&result->bw, 0, sizeof(result->bw));
+        return 0;
+      }
       output_size = VP8LBitWriterNumBytes(&tmp_bw);
       if (output_size > data_size) {
         // compressed size is larger than source! Revert to uncompressed mode.
@@ -314,11 +319,11 @@ static int EncodeAlpha(VP8Encoder* const enc,
   assert(filter >= WEBP_FILTER_NONE && filter <= WEBP_FILTER_FAST);
 
   if (quality < 0 || quality > 100) {
-    return 0;
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_INVALID_CONFIGURATION);
   }
 
   if (method < ALPHA_NO_COMPRESSION || method > ALPHA_LOSSLESS_COMPRESSION) {
-    return 0;
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_INVALID_CONFIGURATION);
   }
 
   if (method == ALPHA_NO_COMPRESSION) {
@@ -328,7 +333,7 @@ static int EncodeAlpha(VP8Encoder* const enc,
 
   quant_alpha = (uint8_t*)WebPSafeMalloc(1ULL, data_size);
   if (quant_alpha == NULL) {
-    return 0;
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
   }
 
   // Extract alpha data (width x height) from raw_data (stride x height).
@@ -348,6 +353,9 @@ static int EncodeAlpha(VP8Encoder* const enc,
     ok = ApplyFiltersAndEncode(quant_alpha, width, height, data_size, method,
                                filter, reduce_levels, effort_level, output,
                                output_size, pic->stats);
+    if (!ok) {
+      WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);  // imprecise
+    }
 #if !defined(WEBP_DISABLE_STATS)
     if (pic->stats != NULL) {  // need stats?
       pic->stats->coded_size += (int)(*output_size);
@@ -407,7 +415,7 @@ int VP8EncStartAlpha(VP8Encoder* const enc) {
       WebPWorker* const worker = &enc->alpha_worker_;
       // Makes sure worker is good to go.
       if (!WebPGetWorkerInterface()->Reset(worker)) {
-        return 0;
+        return WebPEncodingSetError(enc->pic_, VP8_ENC_ERROR_OUT_OF_MEMORY);
       }
       WebPGetWorkerInterface()->Launch(worker);
       return 1;

src/enc/analysis_enc.c

@@ -474,6 +474,10 @@ int VP8EncAnalyze(VP8Encoder* const enc) {
   } else {   // Use only one default segment.
     ResetAllMBInfo(enc);
   }
+  if (!ok) {
+    return WebPEncodingSetError(enc->pic_,
+                                VP8_ENC_ERROR_OUT_OF_MEMORY);  // imprecise
+  }
   return ok;
 }
 

src/enc/backward_references_enc.c

@@ -283,8 +283,7 @@ int VP8LHashChainFill(VP8LHashChain* const p, int quality,
   hash_to_first_index =
       (int32_t*)WebPSafeMalloc(HASH_SIZE, sizeof(*hash_to_first_index));
   if (hash_to_first_index == NULL) {
-    WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
-    return 0;
   }
 
   percent_range = remaining_percent / 2;
@@ -1050,8 +1049,7 @@ int VP8LGetBackwardReferences(
     refs_best = GetBackwardReferencesLowEffort(
         width, height, argb, cache_bits_best, hash_chain, refs);
     if (refs_best == NULL) {
-      WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+      return WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
-      return 0;
     }
     // Set it in first position.
     BackwardRefsSwap(refs_best, &refs[0]);
@@ -1059,8 +1057,7 @@ int VP8LGetBackwardReferences(
     if (!GetBackwardReferences(width, height, argb, quality, lz77_types_to_try,
                                cache_bits_max, do_no_cache, hash_chain, refs,
                                cache_bits_best)) {
-      WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+      return WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
-      return 0;
     }
   }
 

src/enc/frame_enc.c

@@ -689,7 +689,7 @@ static int PreLoopInitialize(VP8Encoder* const enc) {
   }
   if (!ok) {
     VP8EncFreeBitWriters(enc);  // malloc error occurred
-    WebPEncodingSetError(enc->pic_, VP8_ENC_ERROR_OUT_OF_MEMORY);
+    return WebPEncodingSetError(enc->pic_, VP8_ENC_ERROR_OUT_OF_MEMORY);
   }
   return ok;
 }
@@ -719,6 +719,7 @@ static int PostLoopFinalize(VP8EncIterator* const it, int ok) {
   } else {
     // Something bad happened -> need to do some memory cleanup.
     VP8EncFreeBitWriters(enc);
+    return WebPEncodingSetError(enc->pic_, VP8_ENC_ERROR_OUT_OF_MEMORY);
   }
   return ok;
 }
@@ -754,6 +755,11 @@ int VP8EncLoop(VP8Encoder* const enc) {
     // *then* decide how to code the skip decision if there's one.
     if (!VP8Decimate(&it, &info, rd_opt) || dont_use_skip) {
       CodeResiduals(it.bw_, &it, &info);
+      if (it.bw_->error_) {
+        // enc->pic_->error_code is set in PostLoopFinalize().
+        ok = 0;
+        break;
+      }
     } else {   // reset predictors after a skip
       ResetAfterSkip(&it);
     }

src/enc/picture_csp_enc.c

@@ -535,7 +535,9 @@ static int ImportYUVAFromRGBA(const uint8_t* r_ptr,
     WebPInitConvertARGBToYUV();
     InitGammaTables();
 
-    if (tmp_rgb == NULL) return 0;  // malloc error
+    if (tmp_rgb == NULL) {
+      return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+    }
 
     // Downsample Y/U/V planes, two rows at a time
     for (y = 0; y < (height >> 1); ++y) {

src/enc/picture_rescale_enc.c

@@ -137,7 +137,9 @@ int WebPPictureCrop(WebPPicture* pic,
   PictureGrabSpecs(pic, &tmp);
   tmp.width = width;
   tmp.height = height;
-  if (!WebPPictureAlloc(&tmp)) return 0;
+  if (!WebPPictureAlloc(&tmp)) {
+    return WebPEncodingSetError(pic, tmp.error_code);
+  }
 
   if (!pic->use_argb) {
     const int y_offset = top * pic->y_stride + left;
@@ -212,26 +214,28 @@ int WebPPictureRescale(WebPPicture* picture, int width, int height) {
   prev_height = picture->height;
   if (!WebPRescalerGetScaledDimensions(
           prev_width, prev_height, &width, &height)) {
-    return 0;
+    return WebPEncodingSetError(picture, VP8_ENC_ERROR_BAD_DIMENSION);
   }
 
   PictureGrabSpecs(picture, &tmp);
   tmp.width = width;
   tmp.height = height;
-  if (!WebPPictureAlloc(&tmp)) return 0;
+  if (!WebPPictureAlloc(&tmp)) {
+    return WebPEncodingSetError(picture, tmp.error_code);
+  }
 
   if (!picture->use_argb) {
     work = (rescaler_t*)WebPSafeMalloc(2ULL * width, sizeof(*work));
     if (work == NULL) {
       WebPPictureFree(&tmp);
-      return 0;
+      return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
     }
     // If present, we need to rescale alpha first (for AlphaMultiplyY).
     if (picture->a != NULL) {
       WebPInitAlphaProcessing();
       if (!RescalePlane(picture->a, prev_width, prev_height, picture->a_stride,
                         tmp.a, width, height, tmp.a_stride, work, 1)) {
-        return 0;
+        return WebPEncodingSetError(picture, VP8_ENC_ERROR_BAD_DIMENSION);
       }
     }
 
@@ -246,14 +250,14 @@ int WebPPictureRescale(WebPPicture* picture, int width, int height) {
         !RescalePlane(picture->v, HALVE(prev_width), HALVE(prev_height),
                       picture->uv_stride, tmp.v, HALVE(width), HALVE(height),
                       tmp.uv_stride, work, 1)) {
-      return 0;
+      return WebPEncodingSetError(picture, VP8_ENC_ERROR_BAD_DIMENSION);
     }
     AlphaMultiplyY(&tmp, 1);
   } else {
     work = (rescaler_t*)WebPSafeMalloc(2ULL * width * 4, sizeof(*work));
     if (work == NULL) {
       WebPPictureFree(&tmp);
-      return 0;
+      return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
     }
     // In order to correctly interpolate colors, we need to apply the alpha
     // weighting first (black-matting), scale the RGB values, and remove
@@ -263,7 +267,7 @@ int WebPPictureRescale(WebPPicture* picture, int width, int height) {
     if (!RescalePlane((const uint8_t*)picture->argb, prev_width, prev_height,
                       picture->argb_stride * 4, (uint8_t*)tmp.argb, width,
                       height, tmp.argb_stride * 4, work, 4)) {
-      return 0;
+      return WebPEncodingSetError(picture, VP8_ENC_ERROR_BAD_DIMENSION);
     }
     AlphaMultiplyARGB(&tmp, 1);
   }

src/enc/syntax_enc.c

@@ -258,7 +258,10 @@ static int EmitPartitionsSize(const VP8Encoder* const enc,
     buf[3 * p + 1] = (part_size >>  8) & 0xff;
     buf[3 * p + 2] = (part_size >> 16) & 0xff;
   }
-  return p ? pic->writer(buf, 3 * p, pic) : 1;
+  if (p && !pic->writer(buf, 3 * p, pic)) {
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_WRITE);
+  }
+  return 1;
 }
 
 //------------------------------------------------------------------------------
@@ -381,6 +384,7 @@ int VP8EncWrite(VP8Encoder* const enc) {
 
   enc->coded_size_ = (int)(CHUNK_HEADER_SIZE + riff_size);
   ok = ok && WebPReportProgress(pic, final_percent, &enc->percent_);
+  if (!ok) WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_WRITE);
   return ok;
 }
 

src/enc/vp8i_enc.h

@@ -32,7 +32,7 @@ extern "C" {
 // version numbers
 #define ENC_MAJ_VERSION 1
 #define ENC_MIN_VERSION 3
-#define ENC_REV_VERSION 0
+#define ENC_REV_VERSION 1
 
 enum { MAX_LF_LEVELS = 64,       // Maximum loop filter level
        MAX_VARIABLE_LEVEL = 67,  // last (inclusive) level with variable cost

src/enc/vp8l_enc.c

@@ -196,8 +196,7 @@ static int CoOccurrenceBuild(const WebPPicture* const pic,
   uint32_t palette_sorted[MAX_PALETTE_SIZE];
   lines = (uint32_t*)WebPSafeMalloc(2 * pic->width, sizeof(*lines));
   if (lines == NULL) {
-    WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
-    return 0;
   }
   line_top = &lines[0];
   line_current = &lines[pic->width];
@@ -255,8 +254,7 @@ static int PaletteSortModifiedZeng(
   cooccurrence =
       (uint32_t*)WebPSafeCalloc(num_colors * num_colors, sizeof(*cooccurrence));
   if (cooccurrence == NULL) {
-    WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
-    return 0;
   }
   if (!CoOccurrenceBuild(pic, palette_sorted, num_colors, cooccurrence)) {
     WebPSafeFree(cooccurrence);
@@ -1013,8 +1011,7 @@ static int StoreImageToBitMask(
     VP8LRefsCursorNext(&c);
   }
   if (bw->error_) {
-    WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
-    return 0;
   }
   return 1;
 }
@@ -1298,7 +1295,10 @@ static int EncodeImageInternal(
           }
         }
         tokens = (HuffmanTreeToken*)WebPSafeMalloc(max_tokens, sizeof(*tokens));
-        if (tokens == NULL) goto Error;
+        if (tokens == NULL) {
+          WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+          goto Error;
+        }
         for (i = 0; i < 5 * histogram_image_size; ++i) {
           HuffmanTreeCode* const codes = &huffman_codes[i];
           StoreHuffmanCode(bw, huff_tree, tokens, codes);
@@ -1449,18 +1449,21 @@ static int WriteImage(const WebPPicture* const pic, VP8LBitWriter* const bw,
   const size_t vp8l_size = VP8L_SIGNATURE_SIZE + webpll_size;
   const size_t pad = vp8l_size & 1;
   const size_t riff_size = TAG_SIZE + CHUNK_HEADER_SIZE + vp8l_size + pad;
+  *coded_size = 0;
+
+  if (bw->error_) {
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+  }
 
   if (!WriteRiffHeader(pic, riff_size, vp8l_size) ||
       !pic->writer(webpll_data, webpll_size, pic)) {
-    WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_WRITE);
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_WRITE);
-    return 0;
   }
 
   if (pad) {
     const uint8_t pad_byte[1] = { 0 };
     if (!pic->writer(pad_byte, 1, pic)) {
-      WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_WRITE);
+      return WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_WRITE);
-      return 0;
     }
   }
   *coded_size = CHUNK_HEADER_SIZE + riff_size;
@@ -1505,8 +1508,7 @@ static int AllocateTransformBuffer(VP8LEncoder* const enc, int width,
     ClearTransformBuffer(enc);
     mem = (uint32_t*)WebPSafeMalloc(mem_size, sizeof(*mem));
     if (mem == NULL) {
-      WebPEncodingSetError(enc->pic_, VP8_ENC_ERROR_OUT_OF_MEMORY);
+      return WebPEncodingSetError(enc->pic_, VP8_ENC_ERROR_OUT_OF_MEMORY);
-      return 0;
     }
     enc->transform_mem_ = mem;
     enc->transform_mem_size_ = (size_t)mem_size;
@@ -1614,8 +1616,7 @@ static int ApplyPalette(const uint32_t* src, uint32_t src_stride, uint32_t* dst,
   int x, y;
 
   if (tmp_row == NULL) {
-    WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+    return WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
-    return 0;
   }
 
   if (palette_size < APPLY_PALETTE_GREEDY_MAX) {
@@ -1969,9 +1970,8 @@ int VP8LEncodeStream(const WebPConfig* const config,
   int ok_main;
 
   if (enc_main == NULL || !VP8LBitWriterInit(&bw_side, 0)) {
-    WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
     VP8LEncoderDelete(enc_main);
-    return 0;
+    return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
   }
 
   // Avoid "garbage value" error from Clang's static analysis tool.
@@ -2118,8 +2118,7 @@ int VP8LEncodeImage(const WebPConfig* const config,
   if (picture == NULL) return 0;
 
   if (config == NULL || picture->argb == NULL) {
-    WebPEncodingSetError(picture, VP8_ENC_ERROR_NULL_PARAMETER);
+    return WebPEncodingSetError(picture, VP8_ENC_ERROR_NULL_PARAMETER);
-    return 0;
   }
 
   width = picture->width;

src/enc/webp_enc.c

@@ -307,7 +307,10 @@ int WebPEncodingSetError(const WebPPicture* const pic,
                          WebPEncodingError error) {
   assert((int)error < VP8_ENC_ERROR_LAST);
   assert((int)error >= VP8_ENC_OK);
-  ((WebPPicture*)pic)->error_code = error;
+  // The oldest error reported takes precedence over the new one.
+  if (pic->error_code == VP8_ENC_OK) {
+    ((WebPPicture*)pic)->error_code = error;
+  }
   return 0;
 }
 
@@ -317,8 +320,7 @@ int WebPReportProgress(const WebPPicture* const pic,
     *percent_store = percent;
     if (pic->progress_hook && !pic->progress_hook(percent, pic)) {
       // user abort requested
-      WebPEncodingSetError(pic, VP8_ENC_ERROR_USER_ABORT);
+      return WebPEncodingSetError(pic, VP8_ENC_ERROR_USER_ABORT);
-      return 0;
     }
   }
   return 1;  // ok
@@ -329,7 +331,7 @@ int WebPEncode(const WebPConfig* config, WebPPicture* pic) {
   int ok = 0;
   if (pic == NULL) return 0;
 
-  WebPEncodingSetError(pic, VP8_ENC_OK);  // all ok so far
+  pic->error_code = VP8_ENC_OK;  // all ok so far
   if (config == NULL) {  // bad params
     return WebPEncodingSetError(pic, VP8_ENC_ERROR_NULL_PARAMETER);
   }

src/libwebp.rc

@@ -6,8 +6,8 @@
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 1,0,3,0
+ FILEVERSION 1,0,3,1
- PRODUCTVERSION 1,0,3,0
+ PRODUCTVERSION 1,0,3,1
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -24,12 +24,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Google, Inc."
             VALUE "FileDescription", "libwebp DLL"
-            VALUE "FileVersion", "1.3.0"
+            VALUE "FileVersion", "1.3.1"
             VALUE "InternalName", "libwebp.dll"
-            VALUE "LegalCopyright", "Copyright (C) 2022"
+            VALUE "LegalCopyright", "Copyright (C) 2023"
             VALUE "OriginalFilename", "libwebp.dll"
             VALUE "ProductName", "WebP Image Codec"
-            VALUE "ProductVersion", "1.3.0"
+            VALUE "ProductVersion", "1.3.1"
         END
     END
     BLOCK "VarFileInfo"

src/libwebpdecoder.rc

@@ -6,8 +6,8 @@
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 1,0,3,0
+ FILEVERSION 1,0,3,1
- PRODUCTVERSION 1,0,3,0
+ PRODUCTVERSION 1,0,3,1
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -24,12 +24,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Google, Inc."
             VALUE "FileDescription", "libwebpdecoder DLL"
-            VALUE "FileVersion", "1.3.0"
+            VALUE "FileVersion", "1.3.1"
             VALUE "InternalName", "libwebpdecoder.dll"
-            VALUE "LegalCopyright", "Copyright (C) 2022"
+            VALUE "LegalCopyright", "Copyright (C) 2023"
             VALUE "OriginalFilename", "libwebpdecoder.dll"
             VALUE "ProductName", "WebP Image Decoder"
-            VALUE "ProductVersion", "1.3.0"
+            VALUE "ProductVersion", "1.3.1"
         END
     END
     BLOCK "VarFileInfo"

src/mux/Makefile.am

@@ -17,6 +17,6 @@ noinst_HEADERS =
 noinst_HEADERS += ../webp/format_constants.h
 
 libwebpmux_la_LIBADD = ../libwebp.la
-libwebpmux_la_LDFLAGS = -no-undefined -version-info 3:11:0 -lm
+libwebpmux_la_LDFLAGS = -no-undefined -version-info 3:12:0 -lm
 libwebpmuxincludedir = $(includedir)/webp
 pkgconfig_DATA = libwebpmux.pc

src/mux/libwebpmux.rc

@@ -6,8 +6,8 @@
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 1,0,3,0
+ FILEVERSION 1,0,3,1
- PRODUCTVERSION 1,0,3,0
+ PRODUCTVERSION 1,0,3,1
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -24,12 +24,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Google, Inc."
             VALUE "FileDescription", "libwebpmux DLL"
-            VALUE "FileVersion", "1.3.0"
+            VALUE "FileVersion", "1.3.1"
             VALUE "InternalName", "libwebpmux.dll"
-            VALUE "LegalCopyright", "Copyright (C) 2022"
+            VALUE "LegalCopyright", "Copyright (C) 2023"
             VALUE "OriginalFilename", "libwebpmux.dll"
             VALUE "ProductName", "WebP Image Muxer"
-            VALUE "ProductVersion", "1.3.0"
+            VALUE "ProductVersion", "1.3.1"
         END
     END
     BLOCK "VarFileInfo"

src/mux/muxi.h

@@ -29,7 +29,7 @@ extern "C" {
 
 #define MUX_MAJ_VERSION 1
 #define MUX_MIN_VERSION 3
-#define MUX_REV_VERSION 0
+#define MUX_REV_VERSION 1
 
 // Chunk object.
 typedef struct WebPChunk WebPChunk;

src/mux/muxread.c

@@ -116,9 +116,12 @@ static int MuxImageParse(const WebPChunk* const chunk, int copy_data,
     // Each of ANMF chunk contain a header at the beginning. So, its size should
     // be at least 'hdr_size'.
     if (size < hdr_size) goto Fail;
-    ChunkAssignData(&subchunk, &temp, copy_data, chunk->tag_);
+    if (ChunkAssignData(&subchunk, &temp, copy_data,
+                        chunk->tag_) != WEBP_MUX_OK) {
+      goto Fail;
+    }
   }
-  ChunkSetHead(&subchunk, &wpi->header_);
+  if (ChunkSetHead(&subchunk, &wpi->header_) != WEBP_MUX_OK) goto Fail;
   wpi->is_partial_ = 1;  // Waiting for ALPH and/or VP8/VP8L chunks.
 
   // Rest of the chunks.

src/webp/decode.h

@@ -81,10 +81,11 @@ WEBP_EXTERN uint8_t* WebPDecodeBGR(const uint8_t* data, size_t data_size,
 // returned is the Y samples buffer. Upon return, *u and *v will point to
 // the U and V chroma data. These U and V buffers need NOT be passed to
 // WebPFree(), unlike the returned Y luma one. The dimension of the U and V
-// planes are both (*width + 1) / 2 and (*height + 1)/ 2.
+// planes are both (*width + 1) / 2 and (*height + 1) / 2.
 // Upon return, the Y buffer has a stride returned as '*stride', while U and V
 // have a common stride returned as '*uv_stride'.
-// Return NULL in case of error.
+// 'width' and 'height' may be NULL, the other pointers must not be.
+// Returns NULL in case of error.
 // (*) Also named Y'CbCr. See: https://en.wikipedia.org/wiki/YCbCr
 WEBP_EXTERN uint8_t* WebPDecodeYUV(const uint8_t* data, size_t data_size,
                                    int* width, int* height,