webp_animencoder: Add target to fuzz animation encoding (#1935)

* Add new fuzz target for encoding and misc

- Add fuzz_webp_enc_dec and adapt Dockerfile, build.sh
- Lint existing targets
- Add license headers
- Increase fuzz.dict

* webp_enc_dec: Convert input images to inline C arrays

Local files are not available on oss-fuzz servers.

* webp_enc_dec: Fix timeout by skipping crusher

The target fuzz_webp_enc_dec with msan crashes (timeout)
on a 128*128px image encoding with max compression (crusher).
Reduce crusher encoding to 16*16px and below.
Bug report 10423

* webp_enc_dec: Replace cruncher by lossy alpha encoding

The target fuzz_webp_enc_dec with msan crashes (timeout)
during encoding with max compression (cruncher).
Reduce alpha cruncher encoding to 16*16px and below.
Bug report 10634

* webp_enc_dec: Clamp slow parameters for big images

The target fuzz_webp_enc_dec with ubsan crashes (timeout)
during encoding with heavy compression. The cause can not
be easily removed without reducing performance.
Clamp compression parameters for images bigger than 16*16.
Bug report 10700

* webp_enc_dec: Limit alpha_quality to 99 when method is 6

The target fuzz_webp_enc_dec with asan crashes (timeout)
during encoding with heavy alpha compression.
Clamp alpha compression parameters for images bigger than 16*16.
Bug report 10838

* webp_animencoder: Add target to fuzz animation encoding

Add fuzz_webp_animencoder.cc and modify Dockerfile, build.sh
accordingly.
The thresholds for input size and encoding parameters are low
to prevent timeouts.
Some functions used by fuzz_webp_animencoder and fuzz_webp_enc_dec
have been moved to fuzz.h.

1 files changed, 165 insertions, 0 deletions

diff --git a/projects/libwebp/fuzz_webp_animencoder.cc b/projects/libwebp/fuzz_webp_animencoder.cc
new file mode 100644
index 00000000..f5cb2d13
--- /dev/null
+++ b/projects/libwebp/fuzz_webp_animencoder.cc
@@ -0,0 +1,165 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "fuzz.h"
+#include "webp/encode.h"
+#include "webp/mux.h"
+
+namespace {
+
+const VP8CPUInfo default_VP8GetCPUInfo = VP8GetCPUInfo;
+
+int AddFrame(WebPAnimEncoder** const enc,
+             const WebPAnimEncoderOptions& anim_config, int* const width,
+             int* const height, int timestamp_ms, const uint8_t data[],
+             size_t size, uint32_t* const bit_pos) {
+  if (enc == nullptr || width == nullptr || height == nullptr) {
+    fprintf(stderr, "NULL parameters.\n");
+    if (enc != nullptr) WebPAnimEncoderDelete(*enc);
+    abort();
+  }
+
+  // Init the source picture.
+  WebPPicture pic;
+  if (!WebPPictureInit(&pic)) {
+    fprintf(stderr, "WebPPictureInit failed.\n");
+    WebPAnimEncoderDelete(*enc);
+    abort();
+  }
+  pic.use_argb = Extract(1, data, size, bit_pos);
+
+  // Read the source picture.
+  if (!ExtractSourcePicture(&pic, data, size, bit_pos)) {
+    fprintf(stderr, "Can't read input image.\n");
+    WebPPictureFree(&pic);
+    abort();
+  }
+
+  // Crop and scale.
+  if (*enc == nullptr) {  // First frame will set canvas width and height.
+    if (!ExtractAndCropOrScale(&pic, data, size, bit_pos)) {
+      fprintf(stderr, "ExtractAndCropOrScale failed.");
+      WebPPictureFree(&pic);
+      abort();
+    }
+  } else {  // Other frames will be resized to the first frame's dimensions.
+    if (!WebPPictureRescale(&pic, *width, *height)) {
+      fprintf(stderr, "WebPPictureRescale failed. Size: %d,%d\n", *width,
+              *height);
+      WebPAnimEncoderDelete(*enc);
+      WebPPictureFree(&pic);
+      abort();
+    }
+  }
+
+  // Create encoder if it doesn't exist.
+  if (*enc == nullptr) {
+    *width = pic.width;
+    *height = pic.height;
+    *enc = WebPAnimEncoderNew(*width, *height, &anim_config);
+    if (*enc == nullptr) {
+      fprintf(stderr, "WebPAnimEncoderNew failed.\n");
+      WebPPictureFree(&pic);
+      abort();
+    }
+  }
+
+  // Create frame encoding config.
+  WebPConfig config;
+  if (!ExtractWebPConfig(&config, data, size, bit_pos)) {
+    fprintf(stderr, "ExtractWebPConfig failed.\n");
+    WebPAnimEncoderDelete(*enc);
+    WebPPictureFree(&pic);
+    abort();
+  }
+  // Skip slow settings on big images, it's likely to timeout.
+  if (pic.width * pic.height > 32 * 32) {
+    config.method = (config.method > 4) ? 4 : config.method;
+    config.quality = (config.quality > 99.0f) ? 99.0f : config.quality;
+    config.alpha_quality =
+        (config.alpha_quality > 99) ? 99 : config.alpha_quality;
+  }
+
+  // Encode.
+  if (!WebPAnimEncoderAdd(*enc, &pic, timestamp_ms, &config)) {
+    fprintf(stderr, "WebPEncode failed. Error code: %d\n", pic.error_code);
+    WebPAnimEncoderDelete(*enc);
+    WebPPictureFree(&pic);
+    abort();
+  }
+
+  WebPPictureFree(&pic);
+  return 1;
+}
+
+}  // namespace
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* const data, size_t size) {
+  WebPAnimEncoder* enc = nullptr;
+  int width = 0, height = 0, timestamp_ms = 0;
+  uint32_t bit_pos = 0;
+
+  ExtractAndDisableOptimizations(default_VP8GetCPUInfo, data, size, &bit_pos);
+
+  // Extract a configuration from the packed bits.
+  WebPAnimEncoderOptions anim_config;
+  if (!WebPAnimEncoderOptionsInit(&anim_config)) {
+    fprintf(stderr, "WebPAnimEncoderOptionsInit failed.\n");
+    abort();
+  }
+  anim_config.minimize_size = Extract(1, data, size, &bit_pos);
+  anim_config.kmax = Extract(15, data, size, &bit_pos);
+  const int min_kmin = (anim_config.kmax > 1) ? (anim_config.kmax / 2) : 0;
+  const int max_kmin = (anim_config.kmax > 1) ? (anim_config.kmax - 1) : 0;
+  anim_config.kmin =
+      min_kmin + Extract((uint32_t)(max_kmin - min_kmin), data, size, &bit_pos);
+  anim_config.allow_mixed = Extract(1, data, size, &bit_pos);
+  anim_config.verbose = 0;
+
+  const int nb_frames = 1 + Extract(15, data, size, &bit_pos);
+
+  // For each frame.
+  for (int i = 0; i < nb_frames; ++i) {
+    if (!AddFrame(&enc, anim_config, &width, &height, timestamp_ms, data, size,
+                  &bit_pos)) {
+      return 0;
+    }
+
+    timestamp_ms += (1 << (2 + Extract(15, data, size, &bit_pos))) +
+                    Extract(1, data, size, &bit_pos);  // [1..131073], arbitrary
+  }
+
+  // Assemble.
+  if (!WebPAnimEncoderAdd(enc, nullptr, timestamp_ms, nullptr)) {
+    fprintf(stderr, "Last WebPAnimEncoderAdd failed.");
+    WebPAnimEncoderDelete(enc);
+    abort();
+  }
+  WebPData webp_data;
+  WebPDataInit(&webp_data);
+  if (!WebPAnimEncoderAssemble(enc, &webp_data)) {
+    fprintf(stderr, "WebPAnimEncoderAssemble failed.");
+    WebPAnimEncoderDelete(enc);
+    WebPDataClear(&webp_data);
+    abort();
+  }
+
+  WebPAnimEncoderDelete(enc);
+  WebPDataClear(&webp_data);
+  return 0;
+}