Upstream Android modifications to the image encoders/decoders.
This CL does not update the libjpeg as that change is large enough
to warrant its own CL.
Author: djsollen@google.com
Reviewed By: reed@google.com,robertphillips@google.com,scroggo@google.com
Review URL: https://chromiumcodereview.appspot.com/12604006
git-svn-id: http://skia.googlecode.com/svn/trunk/include@8155 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/images/SkBitmapRegionDecoder.h b/images/SkBitmapRegionDecoder.h
new file mode 100644
index 0000000..0e20a5a
--- /dev/null
+++ b/images/SkBitmapRegionDecoder.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2011 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef SkBitmapRegionDecoder_DEFINED
+#define SkBitmapRegionDecoder_DEFINED
+
+#include "SkBitmap.h"
+#include "SkImageDecoder.h"
+#include "SkStream.h"
+
+class SkIRect;
+
+/**
+ * SkBitmapRegionDecoder can be used to decode a specified rect from an image.
+ * This is particularly useful when the original image is large and you only
+ * need parts of the image.
+ *
+ * However, not all image codecs on all platforms support this feature so be
+ * prepared to fallback to standard decoding if decodeRegion(...) returns false.
+ */
+class SkBitmapRegionDecoder {
+public:
+ SkBitmapRegionDecoder(SkImageDecoder* decoder, SkStream* stream,
+ int width, int height) {
+ fDecoder = decoder;
+ fStream = stream;
+ fWidth = width;
+ fHeight = height;
+ }
+ ~SkBitmapRegionDecoder() {
+ SkDELETE(fDecoder);
+ SkSafeUnref(fStream);
+ }
+
+ bool decodeRegion(SkBitmap* bitmap, const SkIRect& rect,
+ SkBitmap::Config pref, int sampleSize);
+
+ SkImageDecoder* getDecoder() const { return fDecoder; }
+ int getWidth() const { return fWidth; }
+ int getHeight() const { return fHeight; }
+
+private:
+ SkImageDecoder* fDecoder;
+ SkStream* fStream;
+ int fWidth;
+ int fHeight;
+};
+
+#endif
diff --git a/images/SkImageDecoder.h b/images/SkImageDecoder.h
index 6d1bb72..8981b95 100644
--- a/images/SkImageDecoder.h
+++ b/images/SkImageDecoder.h
@@ -13,6 +13,7 @@
#include "SkBitmap.h"
#include "SkBitmapFactory.h"
#include "SkImage.h"
+#include "SkRect.h"
#include "SkRefCnt.h"
class SkStream;
@@ -25,6 +26,7 @@
public:
virtual ~SkImageDecoder();
+ // Should be consistent with kFormatName
enum Format {
kUnknown_Format,
kBMP_Format,
@@ -33,14 +35,19 @@
kJPEG_Format,
kPNG_Format,
kWBMP_Format,
+ kWEBP_Format,
- kLastKnownFormat = kWBMP_Format
+ kLastKnownFormat = kWEBP_Format
};
/** Return the compressed data's format (see Format enum)
*/
virtual Format getFormat() const;
+ /** Return the compressed data's format name.
+ */
+ const char* getFormatName() const;
+
/** Returns true if the decoder should try to dither the resulting image.
The default setting is true.
*/
@@ -51,6 +58,20 @@
*/
void setDitherImage(bool dither) { fDitherImage = dither; }
+ /** Returns true if the decoder should try to decode the
+ resulting image to a higher quality even at the expense of
+ the decoding speed.
+ */
+ bool getPreferQualityOverSpeed() const { return fPreferQualityOverSpeed; }
+
+ /** Set to true if the the decoder should try to decode the
+ resulting image to a higher quality even at the expense of
+ the decoding speed.
+ */
+ void setPreferQualityOverSpeed(bool qualityOverSpeed) {
+ fPreferQualityOverSpeed = qualityOverSpeed;
+ }
+
/** \class Peeker
Base class for optional callbacks to retrieve meta/chunk data out of
@@ -175,11 +196,29 @@
note: document use of Allocator, Peeker and Chooser
*/
- bool decode(SkStream*, SkBitmap* bitmap, SkBitmap::Config pref, Mode);
- bool decode(SkStream* stream, SkBitmap* bitmap, Mode mode) {
- return this->decode(stream, bitmap, SkBitmap::kNo_Config, mode);
+ bool decode(SkStream*, SkBitmap* bitmap, SkBitmap::Config pref, Mode, bool reuseBitmap = false);
+ bool decode(SkStream* stream, SkBitmap* bitmap, Mode mode, bool reuseBitmap = false) {
+ return this->decode(stream, bitmap, SkBitmap::kNo_Config, mode, reuseBitmap);
}
+ /**
+ * Given a stream, build an index for doing tile-based decode.
+ * The built index will be saved in the decoder, and the image size will
+ * be returned in width and height.
+ *
+ * Return true for success or false on failure.
+ */
+ bool buildTileIndex(SkStream*, int *width, int *height);
+
+ /**
+ * Decode a rectangle region in the image specified by rect.
+ * The method can only be called after buildTileIndex().
+ *
+ * Return true for success.
+ * Return false if the index is never built or failing in decoding.
+ */
+ bool decodeRegion(SkBitmap* bitmap, const SkIRect& rect, SkBitmap::Config pref);
+
/** Given a stream, this will try to find an appropriate decoder object.
If none is found, the method returns NULL.
*/
@@ -296,6 +335,38 @@
// must be overridden in subclasses. This guy is called by decode(...)
virtual bool onDecode(SkStream*, SkBitmap* bitmap, Mode) = 0;
+ // If the decoder wants to support tiled based decoding,
+ // this method must be overridden. This guy is called by buildTileIndex(...)
+ virtual bool onBuildTileIndex(SkStream*, int *width, int *height) {
+ return false;
+ }
+
+ // If the decoder wants to support tiled based decoding,
+ // this method must be overridden. This guy is called by decodeRegion(...)
+ virtual bool onDecodeRegion(SkBitmap* bitmap, const SkIRect& rect) {
+ return false;
+ }
+
+ /*
+ * Crop a rectangle from the src Bitmap to the dest Bitmap. src and dst are
+ * both sampled by sampleSize from an original Bitmap.
+ *
+ * @param dst the destination bitmap.
+ * @param src the source bitmap that is sampled by sampleSize from the
+ * original bitmap.
+ * @param sampleSize the sample size that src is sampled from the original bitmap.
+ * @param (dstX, dstY) the upper-left point of the dest bitmap in terms of
+ * the coordinate in the original bitmap.
+ * @param (width, height) the width and height of the unsampled dst.
+ * @param (srcX, srcY) the upper-left point of the src bitimap in terms of
+ * the coordinate in the original bitmap.
+ */
+ void cropBitmap(SkBitmap *dst, SkBitmap *src, int sampleSize,
+ int dstX, int dstY, int width, int height,
+ int srcX, int srcY);
+
+
+
/** Can be queried from within onDecode, to see if the user (possibly in
a different thread) has requested the decode to cancel. If this returns
true, your onDecode() should stop and return false.
@@ -346,6 +417,14 @@
bool fDitherImage;
bool fUsePrefTable;
mutable bool fShouldCancelDecode;
+ bool fPreferQualityOverSpeed;
+
+ /** Contains the image format name.
+ * This should be consistent with Format.
+ *
+ * The format name gives a more meaningful error message than enum.
+ */
+ static const char* sFormatName[];
// illegal
SkImageDecoder(const SkImageDecoder&);
@@ -396,5 +475,6 @@
DECLARE_DECODER_CREATOR(JPEGImageDecoder);
DECLARE_DECODER_CREATOR(PNGImageDecoder);
DECLARE_DECODER_CREATOR(WBMPImageDecoder);
+DECLARE_DECODER_CREATOR(WEBPImageDecoder);
#endif
diff --git a/images/SkImageEncoder.h b/images/SkImageEncoder.h
index 3fbfefa..d4d7169 100644
--- a/images/SkImageEncoder.h
+++ b/images/SkImageEncoder.h
@@ -17,7 +17,8 @@
public:
enum Type {
kJPEG_Type,
- kPNG_Type
+ kPNG_Type,
+ kWEBP_Type
};
static SkImageEncoder* Create(Type);
@@ -80,5 +81,6 @@
// not all of these will be available
DECLARE_ENCODER_CREATOR(JPEGImageEncoder);
DECLARE_ENCODER_CREATOR(PNGImageEncoder);
+DECLARE_ENCODER_CREATOR(WEBPImageEncoder);
#endif
