Add getYUV8Planes() API to SkCodec

src/codec/SkCodecImageGenerator.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCodecImageGenerator.h"
 
 SkImageGenerator* SkCodecImageGenerator::NewFromEncodedCodec(SkData* data) {
     SkCodec* codec = SkCodec::NewFromData(data);
     if (nullptr == codec) {
         return nullptr;
     }
 
     return new SkCodecImageGenerator(codec, data);
 }
 
+static SkImageInfo make_premul(const SkImageInfo& info) {
+    if (kUnpremul_SkAlphaType == info.alphaType()) {
+        return info.makeAlphaType(kPremul_SkAlphaType);
+    }
+
+    return info;
+}
+
 SkCodecImageGenerator::SkCodecImageGenerator(SkCodec* codec, SkData* data)
-    : INHERITED(codec->getInfo())
+    : INHERITED(make_premul(codec->getInfo()))
     , fCodec(codec)
     , fData(SkRef(data))
+    , fYWidth(0)
+    , fUWidth(0)
+    , fVWidth(0)
 {}
 
 SkData* SkCodecImageGenerator::onRefEncodedData(SK_REFENCODEDDATA_CTXPARAM) {
     return SkRef(fData.get());
 }
 
 bool SkCodecImageGenerator::onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
         SkPMColor ctable[], int* ctableCount) {
 
     SkCodec::Result result = fCodec->getPixels(info, pixels, rowBytes, nullptr, ctable,
             ctableCount);
     switch (result) {
         case SkCodec::kSuccess:
         case SkCodec::kIncompleteInput:
             return true;
         default:
             return false;
     }
 }
 
 bool SkCodecImageGenerator::onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
         SkYUVColorSpace* colorSpace) {
-    return false;
+    // TODO (msarett): Change the YUV API in ImageGenerator to match SkCodec.
+    //                 This function is currently a hack to match the implementation
+    //                 in SkCodec with the old API.
+    SkCodec::YUVSizeInfo sizeInfo;
+
+    // If planes is NULL, we just need to return the size.
+    if (nullptr == planes) {
+        bool result = fCodec->queryYUV8(&sizeInfo, colorSpace);
+        if (result) {
+            // Save the true widths
+            fYWidth = sizeInfo.fYSize.width();
+            fUWidth = sizeInfo.fUSize.width();
+            fVWidth = sizeInfo.fVSize.width();
+
+            // Set the sizes so that the client allocates enough memory
+            sizes[0].fWidth = (int) sizeInfo.fYWidthBytes;
+            sizes[0].fHeight = sizeInfo.fYSize.height();
+            sizes[1].fWidth = (int) sizeInfo.fUWidthBytes;
+            sizes[1].fHeight = sizeInfo.fUSize.height();
+            sizes[2].fWidth = (int) sizeInfo.fVWidthBytes;
+            sizes[2].fHeight = sizeInfo.fVSize.height();
+        }
+        return result;
+    }
+
+    // Set the sizeInfo with the true widths and heights
+    SkASSERT(fYWidth != 0 && fUWidth != 0 && fVWidth != 0);
+    sizeInfo.fYSize.set(fYWidth, sizes[0].height());
+    sizeInfo.fUSize.set(fUWidth, sizes[1].height());
+    sizeInfo.fVSize.set(fVWidth, sizes[2].height());
+
+    // Set the sizeInfo with the allocated widths
+    sizeInfo.fYWidthBytes = sizes[0].width();
+    sizeInfo.fUWidthBytes = sizes[1].width();
+    sizeInfo.fVWidthBytes = sizes[2].width();
+    SkCodec::Result result = fCodec->getYUV8Planes(sizeInfo, planes);
+    if ((result == SkCodec::kSuccess || result == SkCodec::kIncompleteInput) && colorSpace) {
+        *colorSpace = kJPEG_SkYUVColorSpace;
+    }
+
+    switch (result) {
+        case SkCodec::kSuccess:
+        case SkCodec::kIncompleteInput:
+            return true;
+        default:
+            return false;
+    }
 }