Prototype of RAW decoding in Skia.

src/codec/SkCodec.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 "SkBmpCodec.h"
 #include "SkCodec.h"
 #include "SkData.h"
 #include "SkCodec_libgif.h"
 #include "SkCodec_libico.h"
 #include "SkCodec_libpng.h"
 #include "SkCodec_wbmp.h"
 #include "SkCodecPriv.h"
 #if !defined(GOOGLE3)
 #include "SkJpegCodec.h"
 #endif
 #include "SkStream.h"
 #include "SkWebpCodec.h"
+#include "SkRawCodec.h"
 
 struct DecoderProc {
     bool (*IsFormat)(const void*, size_t);
     SkCodec* (*NewFromStream)(SkStream*);
 };
 
 static const DecoderProc gDecoderProcs[] = {
 #if !defined(GOOGLE3)
     { SkJpegCodec::IsJpeg, SkJpegCodec::NewFromStream },
 #endif
@@ skipping 47 matching lines @@
     // But this code follows the same pattern as the loop.
     if (SkPngCodec::IsPng(buffer, bytesRead)) {
         codec.reset(SkPngCodec::NewFromStream(streamDeleter.detach(), chunkReader));
     } else {
         for (DecoderProc proc : gDecoderProcs) {
             if (proc.IsFormat(buffer, bytesRead)) {
                 codec.reset(proc.NewFromStream(streamDeleter.detach()));
                 break;
             }
         }
+
+        // Try to treat the input as RAW.
+        codec.reset(SkRawCodec::NewFromStream(streamDeleter.detach()));

[scroggo, 2016/01/06 22:30:20]

I think you need to first check that codec is NULL. Otherwise you'll replace
say, a JPEG codec with a RAW codec, even though we already decided it was a
JPEG. In addition, this will delete the stream (since we gave ownership to the
JPEG codec, and reset will delete that codec, deleting the stream).

[yujieqin, 2016/01/07 09:22:25]

Oh, you are right!

     }
 
     // Set the max size at 128 megapixels (512 MB for kN32).
     // This is about 4x smaller than a test image that takes a few minutes for
     // dm to decode and draw.
     const int32_t maxSize = 1 << 27;
     if (codec && codec->getInfo().width() * codec->getInfo().height() > maxSize) {
         SkCodecPrintf("Error: Image size too large, cannot decode.\n");
         return nullptr;
     } else {
@@ skipping 276 matching lines @@
             SkASSERT(1 == linesRequested || this->getInfo().height() == linesRequested);
             const SkImageInfo fillInfo = info.makeWH(info.width(), 1);
             for (int srcY = linesDecoded; srcY < linesRequested; srcY++) {
                 fillDst = SkTAddOffset<void>(dst, this->outputScanline(srcY) * rowBytes);
                 fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
             }
             break;
         }
     }
 }