Add fuzzing for decoding animated images

Add a new mode to decode all frames of an animated image. Use
incremental decoding, rather than getPixels, since the primary client
uses incremental decoding.

Do not decode animated as index 8, which is only supported for the
first frame.

Change-Id: I5d7ed1a81c1ef37df3701c483486d4beff0f62a7
Reviewed-on: https://skia-review.googlesource.com/5679
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>

1 files changed, 41 insertions, 2 deletions

diff --git a/fuzz/fuzz.cpp b/fuzz/fuzz.cpp
index 67b2a863a7..047bcd8856 100644
--- a/fuzz/fuzz.cpp
+++ b/fuzz/fuzz.cpp
@@ -135,8 +135,8 @@ int fuzz_img(sk_sp<SkData> bytes, uint8_t scale, uint8_t mode) {
     float fscale = (float)pow(2.0f, scale);
     SkDebugf("Scaling factor: %f\n", fscale);
 
-    // We have 4 different modes of decoding, just like DM.
-    mode = mode % 4;
+    // We have 5 different modes of decoding.
+    mode = mode % 5;
     SkDebugf("Mode: %d\n", mode);
 
     // This is mostly copied from DMSrcSink's CodecSrc::draw method.
@@ -148,6 +148,11 @@ int fuzz_img(sk_sp<SkData> bytes, uint8_t scale, uint8_t mode) {
     }
 
     SkImageInfo decodeInfo = codec->getInfo();
+    if (4 == mode && decodeInfo.colorType() == kIndex_8_SkColorType) {
+        // 4 means animated. Frames beyond the first cannot be decoded to
+        // index 8.
+        decodeInfo = decodeInfo.makeColorType(kN32_SkColorType);
+    }
 
     SkISize size = codec->getScaledDimensions(fscale);
     decodeInfo = decodeInfo.makeWH(size.width(), size.height());
@@ -352,6 +357,40 @@ int fuzz_img(sk_sp<SkData> bytes, uint8_t scale, uint8_t mode) {
             SkDebugf("[terminated] Success!\n");
             break;
         }
+        case 4: { //kAnimated_Mode
+            std::vector<SkCodec::FrameInfo> frameInfos = codec->getFrameInfo();
+            if (frameInfos.size() == 0) {
+                SkDebugf("[terminated] Not an animated image\n");
+                break;
+            }
+
+            for (size_t i = 0; i < frameInfos.size(); i++) {
+                options.fFrameIndex = i;
+                auto result = codec->startIncrementalDecode(decodeInfo, bitmap.getPixels(),
+                        bitmap.rowBytes(), &options);
+                if (SkCodec::kSuccess != result) {
+                    SkDebugf("[terminated] failed to start incremental decode "
+                             "in frame %d with error %d\n", i, result);
+                    return 15;
+                }
+
+                result = codec->incrementalDecode();
+                if (result == SkCodec::kIncompleteInput) {
+                    SkDebugf("okay\n");
+                    // Frames beyond this one will not decode.
+                    break;
+                }
+                if (result == SkCodec::kSuccess) {
+                    SkDebugf("okay - decoded frame %d\n", i);
+                } else {
+                    SkDebugf("[terminated] incremental decode failed with "
+                             "error %d\n", result);
+                    return 16;
+                }
+            }
+            SkDebugf("[terminated] Success!\n");
+            break;
+        }
         default:
             SkDebugf("[terminated] Mode not implemented yet\n");
     }