JPEG YUV Decoding

src/images/SkDecodingImageGenerator.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkData.h"
 #include "SkDecodingImageGenerator.h"
 #include "SkImageDecoder.h"
@@ skipping 27 matching lines @@
 
 protected:
     virtual SkData* onRefEncodedData() SK_OVERRIDE;
     virtual bool onGetInfo(SkImageInfo* info) SK_OVERRIDE {
         *info = fInfo;
         return true;
     }
     virtual bool onGetPixels(const SkImageInfo& info,
                              void* pixels, size_t rowBytes,
                              SkPMColor ctable[], int* ctableCount) SK_OVERRIDE;
+    virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
+                                 SkYUVColorSpace* colorSpace) SK_OVERRIDE;
 
 private:
     typedef SkImageGenerator INHERITED;
 };
 
 /**
  *  Special allocator used by getPixels(). Uses preallocated memory
  *  provided if possible, else fall-back on the default allocator
  */
 class TargetAllocator : public SkBitmap::Allocator {
@@ skipping 139 matching lines @@
             return false;
         }
         const int count = ctable->count();
         memcpy(ctableEntries, ctable->lockColors(), count * sizeof(SkPMColor));
         ctable->unlockColors();
         *ctableCount = count;
     }
     return true;
 }
 
+bool DecodingImageGenerator::onGetYUV8Planes(SkISize sizes[3], void* planes[3],
+                                             size_t rowBytes[3], SkYUVColorSpace* colorSpace) {

[reed1, 2014/10/13 13:15:35]

where do we set colorSpace? Seems like we need the codec to tell us that...

[sugoi1, 2014/10/14 15:07:36]

I set it here. For now I set it unconditionally to the JPEG YUV format, as the
only other one available currently is for video. I'll add a virtual function in
the decoder once we have more than 1 possible choice.

[reed1, 2014/10/14 15:34:28]

I don't see where "here" is.

[sugoi1, 2014/10/14 15:46:37]

Sorry, I meant: in this function (next version of the file)

+    if (!fStream->rewind()) {
+        return false;
+    }
+
+    SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(fStream));
+    if (NULL == decoder.get()) {
+        return false;
+    }
+
+    if (!planes || !planes[0]) {
+                return decoder->getYUVComponentSizes(fStream, sizes);
+    }
+    
+    return decoder->decodeToYUV(fStream, sizes, planes, rowBytes);
+}
+
 // A contructor-type function that returns NULL on failure.  This
 // prevents the returned SkImageGenerator from ever being in a bad
 // state.  Called by both Create() functions
 SkImageGenerator* CreateDecodingImageGenerator(
         SkData* data,
         SkStreamRewindable* stream,
         const SkDecodingImageGenerator::Options& opts) {
     SkASSERT(stream);
     SkAutoTUnref<SkStreamRewindable> autoStream(stream);  // always unref this.
     SkAssertResult(autoStream->rewind());
@@ skipping 56 matching lines @@
         SkStreamRewindable* stream,
         const SkDecodingImageGenerator::Options& opts) {
     SkASSERT(stream != NULL);
     SkASSERT(stream->unique());
     if ((stream == NULL) || !stream->unique()) {
         SkSafeUnref(stream);
         return NULL;
     }
     return CreateDecodingImageGenerator(NULL, stream, opts);
 }