7f97f49a84
Bug: skia: Change-Id: I59185b8acc00b6df854c613ba29d1002111fcb42 Reviewed-on: https://skia-review.googlesource.com/27240 Commit-Queue: Mike Klein <mtklein@google.com> Reviewed-by: Mike Klein <mtklein@google.com>
925 lines
34 KiB
C++
925 lines
34 KiB
C++
/*
|
|
* Copyright 2015 Google Inc.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license that can be
|
|
* found in the LICENSE file.
|
|
*/
|
|
|
|
#ifndef SkCodec_DEFINED
|
|
#define SkCodec_DEFINED
|
|
|
|
#include "../private/SkTemplates.h"
|
|
#include "SkCodecAnimation.h"
|
|
#include "SkColor.h"
|
|
#include "SkColorSpaceXform.h"
|
|
#include "SkEncodedImageFormat.h"
|
|
#include "SkEncodedInfo.h"
|
|
#include "SkImageInfo.h"
|
|
#include "SkSize.h"
|
|
#include "SkStream.h"
|
|
#include "SkTypes.h"
|
|
#include "SkYUVSizeInfo.h"
|
|
|
|
#include <vector>
|
|
|
|
class SkColorSpace;
|
|
class SkData;
|
|
class SkFrameHolder;
|
|
class SkPngChunkReader;
|
|
class SkSampler;
|
|
|
|
namespace DM {
|
|
class CodecSrc;
|
|
class ColorCodecSrc;
|
|
}
|
|
class ColorCodecBench;
|
|
|
|
/**
|
|
* Abstraction layer directly on top of an image codec.
|
|
*/
|
|
class SK_API SkCodec : SkNoncopyable {
|
|
public:
|
|
/**
|
|
* Minimum number of bytes that must be buffered in SkStream input.
|
|
*
|
|
* An SkStream passed to NewFromStream must be able to use this many
|
|
* bytes to determine the image type. Then the same SkStream must be
|
|
* passed to the correct decoder to read from the beginning.
|
|
*
|
|
* This can be accomplished by implementing peek() to support peeking
|
|
* this many bytes, or by implementing rewind() to be able to rewind()
|
|
* after reading this many bytes.
|
|
*/
|
|
static size_t MinBufferedBytesNeeded();
|
|
|
|
/**
|
|
* Error codes for various SkCodec methods.
|
|
*/
|
|
enum Result {
|
|
/**
|
|
* General return value for success.
|
|
*/
|
|
kSuccess,
|
|
/**
|
|
* The input is incomplete. A partial image was generated.
|
|
*/
|
|
kIncompleteInput,
|
|
/**
|
|
* Like kIncompleteInput, except the input had an error.
|
|
*
|
|
* If returned from an incremental decode, decoding cannot continue,
|
|
* even with more data.
|
|
*/
|
|
kErrorInInput,
|
|
/**
|
|
* The generator cannot convert to match the request, ignoring
|
|
* dimensions.
|
|
*/
|
|
kInvalidConversion,
|
|
/**
|
|
* The generator cannot scale to requested size.
|
|
*/
|
|
kInvalidScale,
|
|
/**
|
|
* Parameters (besides info) are invalid. e.g. NULL pixels, rowBytes
|
|
* too small, etc.
|
|
*/
|
|
kInvalidParameters,
|
|
/**
|
|
* The input did not contain a valid image.
|
|
*/
|
|
kInvalidInput,
|
|
/**
|
|
* Fulfilling this request requires rewinding the input, which is not
|
|
* supported for this input.
|
|
*/
|
|
kCouldNotRewind,
|
|
/**
|
|
* An internal error, such as OOM.
|
|
*/
|
|
kInternalError,
|
|
/**
|
|
* This method is not implemented by this codec.
|
|
* FIXME: Perhaps this should be kUnsupported?
|
|
*/
|
|
kUnimplemented,
|
|
};
|
|
|
|
/**
|
|
* If this stream represents an encoded image that we know how to decode,
|
|
* return an SkCodec that can decode it. Otherwise return NULL.
|
|
*
|
|
* As stated above, this call must be able to peek or read
|
|
* MinBufferedBytesNeeded to determine the correct format, and then start
|
|
* reading from the beginning. First it will attempt to peek, and it
|
|
* assumes that if less than MinBufferedBytesNeeded bytes (but more than
|
|
* zero) are returned, this is because the stream is shorter than this,
|
|
* so falling back to reading would not provide more data. If peek()
|
|
* returns zero bytes, this call will instead attempt to read(). This
|
|
* will require that the stream can be rewind()ed.
|
|
*
|
|
* If Result is not NULL, it will be set to either kSuccess if an SkCodec
|
|
* is returned or a reason for the failure if NULL is returned.
|
|
*
|
|
* If SkPngChunkReader is not NULL, take a ref and pass it to libpng if
|
|
* the image is a png.
|
|
*
|
|
* If the SkPngChunkReader is not NULL then:
|
|
* If the image is not a PNG, the SkPngChunkReader will be ignored.
|
|
* If the image is a PNG, the SkPngChunkReader will be reffed.
|
|
* If the PNG has unknown chunks, the SkPngChunkReader will be used
|
|
* to handle these chunks. SkPngChunkReader will be called to read
|
|
* any unknown chunk at any point during the creation of the codec
|
|
* or the decode. Note that if SkPngChunkReader fails to read a
|
|
* chunk, this could result in a failure to create the codec or a
|
|
* failure to decode the image.
|
|
* If the PNG does not contain unknown chunks, the SkPngChunkReader
|
|
* will not be used or modified.
|
|
*
|
|
* If NULL is returned, the stream is deleted immediately. Otherwise, the
|
|
* SkCodec takes ownership of it, and will delete it when done with it.
|
|
*/
|
|
static std::unique_ptr<SkCodec> MakeFromStream(std::unique_ptr<SkStream>, Result* = nullptr,
|
|
SkPngChunkReader* = nullptr);
|
|
|
|
/**
|
|
* If this data represents an encoded image that we know how to decode,
|
|
* return an SkCodec that can decode it. Otherwise return NULL.
|
|
*
|
|
* If the SkPngChunkReader is not NULL then:
|
|
* If the image is not a PNG, the SkPngChunkReader will be ignored.
|
|
* If the image is a PNG, the SkPngChunkReader will be reffed.
|
|
* If the PNG has unknown chunks, the SkPngChunkReader will be used
|
|
* to handle these chunks. SkPngChunkReader will be called to read
|
|
* any unknown chunk at any point during the creation of the codec
|
|
* or the decode. Note that if SkPngChunkReader fails to read a
|
|
* chunk, this could result in a failure to create the codec or a
|
|
* failure to decode the image.
|
|
* If the PNG does not contain unknown chunks, the SkPngChunkReader
|
|
* will not be used or modified.
|
|
*/
|
|
static std::unique_ptr<SkCodec> MakeFromData(sk_sp<SkData>, SkPngChunkReader* = nullptr);
|
|
|
|
virtual ~SkCodec();
|
|
|
|
/**
|
|
* Return the ImageInfo associated with this codec.
|
|
*/
|
|
const SkImageInfo& getInfo() const { return fSrcInfo; }
|
|
|
|
const SkEncodedInfo& getEncodedInfo() const { return fEncodedInfo; }
|
|
|
|
enum Origin {
|
|
kTopLeft_Origin = 1, // Default
|
|
kTopRight_Origin = 2, // Reflected across y-axis
|
|
kBottomRight_Origin = 3, // Rotated 180
|
|
kBottomLeft_Origin = 4, // Reflected across x-axis
|
|
kLeftTop_Origin = 5, // Reflected across x-axis, Rotated 90 CCW
|
|
kRightTop_Origin = 6, // Rotated 90 CW
|
|
kRightBottom_Origin = 7, // Reflected across x-axis, Rotated 90 CW
|
|
kLeftBottom_Origin = 8, // Rotated 90 CCW
|
|
kDefault_Origin = kTopLeft_Origin,
|
|
kLast_Origin = kLeftBottom_Origin,
|
|
};
|
|
|
|
/**
|
|
* Returns the image orientation stored in the EXIF data.
|
|
* If there is no EXIF data, or if we cannot read the EXIF data, returns kTopLeft.
|
|
*/
|
|
Origin getOrigin() const { return fOrigin; }
|
|
|
|
/**
|
|
* Return a size that approximately supports the desired scale factor.
|
|
* The codec may not be able to scale efficiently to the exact scale
|
|
* factor requested, so return a size that approximates that scale.
|
|
* The returned value is the codec's suggestion for the closest valid
|
|
* scale that it can natively support
|
|
*/
|
|
SkISize getScaledDimensions(float desiredScale) const {
|
|
// Negative and zero scales are errors.
|
|
SkASSERT(desiredScale > 0.0f);
|
|
if (desiredScale <= 0.0f) {
|
|
return SkISize::Make(0, 0);
|
|
}
|
|
|
|
// Upscaling is not supported. Return the original size if the client
|
|
// requests an upscale.
|
|
if (desiredScale >= 1.0f) {
|
|
return this->getInfo().dimensions();
|
|
}
|
|
return this->onGetScaledDimensions(desiredScale);
|
|
}
|
|
|
|
/**
|
|
* Return (via desiredSubset) a subset which can decoded from this codec,
|
|
* or false if this codec cannot decode subsets or anything similar to
|
|
* desiredSubset.
|
|
*
|
|
* @param desiredSubset In/out parameter. As input, a desired subset of
|
|
* the original bounds (as specified by getInfo). If true is returned,
|
|
* desiredSubset may have been modified to a subset which is
|
|
* supported. Although a particular change may have been made to
|
|
* desiredSubset to create something supported, it is possible other
|
|
* changes could result in a valid subset.
|
|
* If false is returned, desiredSubset's value is undefined.
|
|
* @return true if this codec supports decoding desiredSubset (as
|
|
* returned, potentially modified)
|
|
*/
|
|
bool getValidSubset(SkIRect* desiredSubset) const {
|
|
return this->onGetValidSubset(desiredSubset);
|
|
}
|
|
|
|
/**
|
|
* Format of the encoded data.
|
|
*/
|
|
SkEncodedImageFormat getEncodedFormat() const { return this->onGetEncodedFormat(); }
|
|
|
|
/**
|
|
* Whether or not the memory passed to getPixels is zero initialized.
|
|
*/
|
|
enum ZeroInitialized {
|
|
/**
|
|
* The memory passed to getPixels is zero initialized. The SkCodec
|
|
* may take advantage of this by skipping writing zeroes.
|
|
*/
|
|
kYes_ZeroInitialized,
|
|
/**
|
|
* The memory passed to getPixels has not been initialized to zero,
|
|
* so the SkCodec must write all zeroes to memory.
|
|
*
|
|
* This is the default. It will be used if no Options struct is used.
|
|
*/
|
|
kNo_ZeroInitialized,
|
|
};
|
|
|
|
/**
|
|
* Additional options to pass to getPixels.
|
|
*/
|
|
struct Options {
|
|
Options()
|
|
: fZeroInitialized(kNo_ZeroInitialized)
|
|
, fSubset(nullptr)
|
|
, fFrameIndex(0)
|
|
, fPriorFrame(kNone)
|
|
, fPremulBehavior(SkTransferFunctionBehavior::kRespect)
|
|
{}
|
|
|
|
ZeroInitialized fZeroInitialized;
|
|
/**
|
|
* If not NULL, represents a subset of the original image to decode.
|
|
* Must be within the bounds returned by getInfo().
|
|
* If the EncodedFormat is SkEncodedImageFormat::kWEBP (the only one which
|
|
* currently supports subsets), the top and left values must be even.
|
|
*
|
|
* In getPixels and incremental decode, we will attempt to decode the
|
|
* exact rectangular subset specified by fSubset.
|
|
*
|
|
* In a scanline decode, it does not make sense to specify a subset
|
|
* top or subset height, since the client already controls which rows
|
|
* to get and which rows to skip. During scanline decodes, we will
|
|
* require that the subset top be zero and the subset height be equal
|
|
* to the full height. We will, however, use the values of
|
|
* subset left and subset width to decode partial scanlines on calls
|
|
* to getScanlines().
|
|
*/
|
|
const SkIRect* fSubset;
|
|
|
|
/**
|
|
* The frame to decode.
|
|
*
|
|
* Only meaningful for multi-frame images.
|
|
*/
|
|
int fFrameIndex;
|
|
|
|
/**
|
|
* If not kNone, the dst already contains the prior frame at this index.
|
|
*
|
|
* Only meaningful for multi-frame images.
|
|
*
|
|
* If fFrameIndex needs to be blended with a prior frame (as reported by
|
|
* getFrameInfo[fFrameIndex].fRequiredFrame), the client can set this to
|
|
* any non-kRestorePrevious frame in [fRequiredFrame, fFrameIndex) to
|
|
* indicate that that frame is already in the dst. Options.fZeroInitialized
|
|
* is ignored in this case.
|
|
*
|
|
* If set to kNone, the codec will decode any necessary required frame(s) first.
|
|
*/
|
|
int fPriorFrame;
|
|
|
|
/**
|
|
* Indicates whether we should do a linear premultiply or a legacy premultiply.
|
|
*
|
|
* In the case where the dst SkColorSpace is nullptr, this flag is ignored and
|
|
* we will always do a legacy premultiply.
|
|
*/
|
|
SkTransferFunctionBehavior fPremulBehavior;
|
|
};
|
|
|
|
/**
|
|
* Decode into the given pixels, a block of memory of size at
|
|
* least (info.fHeight - 1) * rowBytes + (info.fWidth *
|
|
* bytesPerPixel)
|
|
*
|
|
* Repeated calls to this function should give the same results,
|
|
* allowing the PixelRef to be immutable.
|
|
*
|
|
* @param info A description of the format (config, size)
|
|
* expected by the caller. This can simply be identical
|
|
* to the info returned by getInfo().
|
|
*
|
|
* This contract also allows the caller to specify
|
|
* different output-configs, which the implementation can
|
|
* decide to support or not.
|
|
*
|
|
* A size that does not match getInfo() implies a request
|
|
* to scale. If the generator cannot perform this scale,
|
|
* it will return kInvalidScale.
|
|
*
|
|
* If the info contains a non-null SkColorSpace, the codec
|
|
* will perform the appropriate color space transformation.
|
|
* If the caller passes in the same color space that was
|
|
* reported by the codec, the color space transformation is
|
|
* a no-op.
|
|
*
|
|
* If a scanline decode is in progress, scanline mode will end, requiring the client to call
|
|
* startScanlineDecode() in order to return to decoding scanlines.
|
|
*
|
|
* @return Result kSuccess, or another value explaining the type of failure.
|
|
*/
|
|
Result getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, const Options*);
|
|
|
|
/**
|
|
* Simplified version of getPixels() that uses the default Options.
|
|
*/
|
|
Result getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes) {
|
|
return this->getPixels(info, pixels, rowBytes, nullptr);
|
|
}
|
|
|
|
/**
|
|
* If decoding to YUV is supported, this returns true. Otherwise, this
|
|
* returns false and does not modify any of the parameters.
|
|
*
|
|
* @param sizeInfo Output parameter indicating the sizes and required
|
|
* allocation widths of the Y, U, and V planes.
|
|
* @param colorSpace Output parameter. If non-NULL this is set to kJPEG,
|
|
* otherwise this is ignored.
|
|
*/
|
|
bool queryYUV8(SkYUVSizeInfo* sizeInfo, SkYUVColorSpace* colorSpace) const {
|
|
if (nullptr == sizeInfo) {
|
|
return false;
|
|
}
|
|
|
|
return this->onQueryYUV8(sizeInfo, colorSpace);
|
|
}
|
|
|
|
/**
|
|
* Returns kSuccess, or another value explaining the type of failure.
|
|
* This always attempts to perform a full decode. If the client only
|
|
* wants size, it should call queryYUV8().
|
|
*
|
|
* @param sizeInfo Needs to exactly match the values returned by the
|
|
* query, except the WidthBytes may be larger than the
|
|
* recommendation (but not smaller).
|
|
* @param planes Memory for each of the Y, U, and V planes.
|
|
*/
|
|
Result getYUV8Planes(const SkYUVSizeInfo& sizeInfo, void* planes[3]) {
|
|
if (nullptr == planes || nullptr == planes[0] || nullptr == planes[1] ||
|
|
nullptr == planes[2]) {
|
|
return kInvalidInput;
|
|
}
|
|
|
|
if (!this->rewindIfNeeded()) {
|
|
return kCouldNotRewind;
|
|
}
|
|
|
|
return this->onGetYUV8Planes(sizeInfo, planes);
|
|
}
|
|
|
|
/**
|
|
* Prepare for an incremental decode with the specified options.
|
|
*
|
|
* This may require a rewind.
|
|
*
|
|
* @param dstInfo Info of the destination. If the dimensions do not match
|
|
* those of getInfo, this implies a scale.
|
|
* @param dst Memory to write to. Needs to be large enough to hold the subset,
|
|
* if present, or the full image as described in dstInfo.
|
|
* @param options Contains decoding options, including if memory is zero
|
|
* initialized and whether to decode a subset.
|
|
* @return Enum representing success or reason for failure.
|
|
*/
|
|
Result startIncrementalDecode(const SkImageInfo& dstInfo, void* dst, size_t rowBytes,
|
|
const Options*);
|
|
|
|
Result startIncrementalDecode(const SkImageInfo& dstInfo, void* dst, size_t rowBytes) {
|
|
return this->startIncrementalDecode(dstInfo, dst, rowBytes, nullptr);
|
|
}
|
|
|
|
/**
|
|
* Start/continue the incremental decode.
|
|
*
|
|
* Not valid to call before calling startIncrementalDecode().
|
|
*
|
|
* After the first call, should only be called again if more data has been
|
|
* provided to the source SkStream.
|
|
*
|
|
* Unlike getPixels and getScanlines, this does not do any filling. This is
|
|
* left up to the caller, since they may be skipping lines or continuing the
|
|
* decode later. In the latter case, they may choose to initialize all lines
|
|
* first, or only initialize the remaining lines after the first call.
|
|
*
|
|
* @param rowsDecoded Optional output variable returning the total number of
|
|
* lines initialized. Only meaningful if this method returns kIncompleteInput.
|
|
* Otherwise the implementation may not set it.
|
|
* Note that some implementations may have initialized this many rows, but
|
|
* not necessarily finished those rows (e.g. interlaced PNG). This may be
|
|
* useful for determining what rows the client needs to initialize.
|
|
* @return kSuccess if all lines requested in startIncrementalDecode have
|
|
* been completely decoded. kIncompleteInput otherwise.
|
|
*/
|
|
Result incrementalDecode(int* rowsDecoded = nullptr) {
|
|
if (!fStartedIncrementalDecode) {
|
|
return kInvalidParameters;
|
|
}
|
|
return this->onIncrementalDecode(rowsDecoded);
|
|
}
|
|
|
|
/**
|
|
* The remaining functions revolve around decoding scanlines.
|
|
*/
|
|
|
|
/**
|
|
* Prepare for a scanline decode with the specified options.
|
|
*
|
|
* After this call, this class will be ready to decode the first scanline.
|
|
*
|
|
* This must be called in order to call getScanlines or skipScanlines.
|
|
*
|
|
* This may require rewinding the stream.
|
|
*
|
|
* Not all SkCodecs support this.
|
|
*
|
|
* @param dstInfo Info of the destination. If the dimensions do not match
|
|
* those of getInfo, this implies a scale.
|
|
* @param options Contains decoding options, including if memory is zero
|
|
* initialized.
|
|
* @return Enum representing success or reason for failure.
|
|
*/
|
|
Result startScanlineDecode(const SkImageInfo& dstInfo, const Options* options);
|
|
|
|
/**
|
|
* Simplified version of startScanlineDecode() that uses the default Options.
|
|
*/
|
|
Result startScanlineDecode(const SkImageInfo& dstInfo) {
|
|
return this->startScanlineDecode(dstInfo, nullptr);
|
|
}
|
|
|
|
/**
|
|
* Write the next countLines scanlines into dst.
|
|
*
|
|
* Not valid to call before calling startScanlineDecode().
|
|
*
|
|
* @param dst Must be non-null, and large enough to hold countLines
|
|
* scanlines of size rowBytes.
|
|
* @param countLines Number of lines to write.
|
|
* @param rowBytes Number of bytes per row. Must be large enough to hold
|
|
* a scanline based on the SkImageInfo used to create this object.
|
|
* @return the number of lines successfully decoded. If this value is
|
|
* less than countLines, this will fill the remaining lines with a
|
|
* default value.
|
|
*/
|
|
int getScanlines(void* dst, int countLines, size_t rowBytes);
|
|
|
|
/**
|
|
* Skip count scanlines.
|
|
*
|
|
* Not valid to call before calling startScanlineDecode().
|
|
*
|
|
* The default version just calls onGetScanlines and discards the dst.
|
|
* NOTE: If skipped lines are the only lines with alpha, this default
|
|
* will make reallyHasAlpha return true, when it could have returned
|
|
* false.
|
|
*
|
|
* @return true if the scanlines were successfully skipped
|
|
* false on failure, possible reasons for failure include:
|
|
* An incomplete input image stream.
|
|
* Calling this function before calling startScanlineDecode().
|
|
* If countLines is less than zero or so large that it moves
|
|
* the current scanline past the end of the image.
|
|
*/
|
|
bool skipScanlines(int countLines);
|
|
|
|
/**
|
|
* The order in which rows are output from the scanline decoder is not the
|
|
* same for all variations of all image types. This explains the possible
|
|
* output row orderings.
|
|
*/
|
|
enum SkScanlineOrder {
|
|
/*
|
|
* By far the most common, this indicates that the image can be decoded
|
|
* reliably using the scanline decoder, and that rows will be output in
|
|
* the logical order.
|
|
*/
|
|
kTopDown_SkScanlineOrder,
|
|
|
|
/*
|
|
* This indicates that the scanline decoder reliably outputs rows, but
|
|
* they will be returned in reverse order. If the scanline format is
|
|
* kBottomUp, the nextScanline() API can be used to determine the actual
|
|
* y-coordinate of the next output row, but the client is not forced
|
|
* to take advantage of this, given that it's not too tough to keep
|
|
* track independently.
|
|
*
|
|
* For full image decodes, it is safe to get all of the scanlines at
|
|
* once, since the decoder will handle inverting the rows as it
|
|
* decodes.
|
|
*
|
|
* For subset decodes and sampling, it is simplest to get and skip
|
|
* scanlines one at a time, using the nextScanline() API. It is
|
|
* possible to ask for larger chunks at a time, but this should be used
|
|
* with caution. As with full image decodes, the decoder will handle
|
|
* inverting the requested rows, but rows will still be delivered
|
|
* starting from the bottom of the image.
|
|
*
|
|
* Upside down bmps are an example.
|
|
*/
|
|
kBottomUp_SkScanlineOrder,
|
|
};
|
|
|
|
/**
|
|
* An enum representing the order in which scanlines will be returned by
|
|
* the scanline decoder.
|
|
*
|
|
* This is undefined before startScanlineDecode() is called.
|
|
*/
|
|
SkScanlineOrder getScanlineOrder() const { return this->onGetScanlineOrder(); }
|
|
|
|
/**
|
|
* Returns the y-coordinate of the next row to be returned by the scanline
|
|
* decoder.
|
|
*
|
|
* This will equal fCurrScanline, except in the case of strangely
|
|
* encoded image types (bottom-up bmps).
|
|
*
|
|
* Results are undefined when not in scanline decoding mode.
|
|
*/
|
|
int nextScanline() const { return this->outputScanline(fCurrScanline); }
|
|
|
|
/**
|
|
* Returns the output y-coordinate of the row that corresponds to an input
|
|
* y-coordinate. The input y-coordinate represents where the scanline
|
|
* is located in the encoded data.
|
|
*
|
|
* This will equal inputScanline, except in the case of strangely
|
|
* encoded image types (bottom-up bmps, interlaced gifs).
|
|
*/
|
|
int outputScanline(int inputScanline) const;
|
|
|
|
/**
|
|
* Return the number of frames in the image.
|
|
*
|
|
* May require reading through the stream.
|
|
*/
|
|
int getFrameCount() {
|
|
return this->onGetFrameCount();
|
|
}
|
|
|
|
// The required frame for an independent frame is marked as
|
|
// kNone.
|
|
static constexpr int kNone = -1;
|
|
|
|
/**
|
|
* Information about individual frames in a multi-framed image.
|
|
*/
|
|
struct FrameInfo {
|
|
/**
|
|
* The frame that this frame needs to be blended with, or
|
|
* kNone if this frame is independent.
|
|
*
|
|
* Note that this is the *earliest* frame that can be used
|
|
* for blending. Any frame from [fRequiredFrame, i) can be
|
|
* used, unless its fDisposalMethod is kRestorePrevious.
|
|
*/
|
|
int fRequiredFrame;
|
|
|
|
/**
|
|
* Number of milliseconds to show this frame.
|
|
*/
|
|
int fDuration;
|
|
|
|
/**
|
|
* Whether the end marker for this frame is contained in the stream.
|
|
*
|
|
* Note: this does not guarantee that an attempt to decode will be complete.
|
|
* There could be an error in the stream.
|
|
*/
|
|
bool fFullyReceived;
|
|
|
|
/**
|
|
* This is conservative; it will still return non-opaque if e.g. a
|
|
* color index-based frame has a color with alpha but does not use it.
|
|
*/
|
|
SkAlphaType fAlphaType;
|
|
|
|
/**
|
|
* How this frame should be modified before decoding the next one.
|
|
*/
|
|
SkCodecAnimation::DisposalMethod fDisposalMethod;
|
|
};
|
|
|
|
/**
|
|
* Return info about a single frame.
|
|
*
|
|
* Only supported by multi-frame images. Does not read through the stream,
|
|
* so it should be called after getFrameCount() to parse any frames that
|
|
* have not already been parsed.
|
|
*/
|
|
bool getFrameInfo(int index, FrameInfo* info) const {
|
|
if (index < 0) {
|
|
return false;
|
|
}
|
|
return this->onGetFrameInfo(index, info);
|
|
}
|
|
|
|
/**
|
|
* Return info about all the frames in the image.
|
|
*
|
|
* May require reading through the stream to determine info about the
|
|
* frames (including the count).
|
|
*
|
|
* As such, future decoding calls may require a rewind.
|
|
*
|
|
* For single-frame images, this will return an empty vector.
|
|
*/
|
|
std::vector<FrameInfo> getFrameInfo();
|
|
|
|
static constexpr int kRepetitionCountInfinite = -1;
|
|
|
|
/**
|
|
* Return the number of times to repeat, if this image is animated.
|
|
*
|
|
* May require reading the stream to find the repetition count.
|
|
*
|
|
* As such, future decoding calls may require a rewind.
|
|
*
|
|
* For single-frame images, this will return 0.
|
|
*/
|
|
int getRepetitionCount() {
|
|
return this->onGetRepetitionCount();
|
|
}
|
|
|
|
protected:
|
|
using XformFormat = SkColorSpaceXform::ColorFormat;
|
|
|
|
SkCodec(int width,
|
|
int height,
|
|
const SkEncodedInfo&,
|
|
XformFormat srcFormat,
|
|
std::unique_ptr<SkStream>,
|
|
sk_sp<SkColorSpace>,
|
|
Origin = kTopLeft_Origin);
|
|
|
|
/**
|
|
* Allows the subclass to set the recommended SkImageInfo
|
|
*/
|
|
SkCodec(const SkEncodedInfo&,
|
|
const SkImageInfo&,
|
|
XformFormat srcFormat,
|
|
std::unique_ptr<SkStream>,
|
|
Origin = kTopLeft_Origin);
|
|
|
|
virtual SkISize onGetScaledDimensions(float /*desiredScale*/) const {
|
|
// By default, scaling is not supported.
|
|
return this->getInfo().dimensions();
|
|
}
|
|
|
|
// FIXME: What to do about subsets??
|
|
/**
|
|
* Subclasses should override if they support dimensions other than the
|
|
* srcInfo's.
|
|
*/
|
|
virtual bool onDimensionsSupported(const SkISize&) {
|
|
return false;
|
|
}
|
|
|
|
virtual SkEncodedImageFormat onGetEncodedFormat() const = 0;
|
|
|
|
/**
|
|
* @param rowsDecoded When the encoded image stream is incomplete, this function
|
|
* will return kIncompleteInput and rowsDecoded will be set to
|
|
* the number of scanlines that were successfully decoded.
|
|
* This will allow getPixels() to fill the uninitialized memory.
|
|
*/
|
|
virtual Result onGetPixels(const SkImageInfo& info,
|
|
void* pixels, size_t rowBytes, const Options&,
|
|
int* rowsDecoded) = 0;
|
|
|
|
virtual bool onQueryYUV8(SkYUVSizeInfo*, SkYUVColorSpace*) const {
|
|
return false;
|
|
}
|
|
|
|
virtual Result onGetYUV8Planes(const SkYUVSizeInfo&, void*[3] /*planes*/) {
|
|
return kUnimplemented;
|
|
}
|
|
|
|
virtual bool onGetValidSubset(SkIRect* /*desiredSubset*/) const {
|
|
// By default, subsets are not supported.
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* If the stream was previously read, attempt to rewind.
|
|
*
|
|
* If the stream needed to be rewound, call onRewind.
|
|
* @returns true if the codec is at the right position and can be used.
|
|
* false if there was a failure to rewind.
|
|
*
|
|
* This is called by getPixels() and start(). Subclasses may call if they
|
|
* need to rewind at another time.
|
|
*/
|
|
bool SK_WARN_UNUSED_RESULT rewindIfNeeded();
|
|
|
|
/**
|
|
* Called by rewindIfNeeded, if the stream needed to be rewound.
|
|
*
|
|
* Subclasses should do any set up needed after a rewind.
|
|
*/
|
|
virtual bool onRewind() {
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* On an incomplete input, getPixels() and getScanlines() will fill any uninitialized
|
|
* scanlines. This allows the subclass to indicate what value to fill with.
|
|
*
|
|
* @param dstInfo Describes the destination.
|
|
* @return The value with which to fill uninitialized pixels.
|
|
*
|
|
* Note that we can interpret the return value as a 64-bit Float16 color, a SkPMColor,
|
|
* a 16-bit 565 color, an 8-bit gray color, or an 8-bit index into a color table,
|
|
* depending on the color type.
|
|
*/
|
|
uint64_t getFillValue(const SkImageInfo& dstInfo) const {
|
|
return this->onGetFillValue(dstInfo);
|
|
}
|
|
|
|
/**
|
|
* Some subclasses will override this function, but this is a useful default for the color
|
|
* types that we support. Note that for color types that do not use the full 64-bits,
|
|
* we will simply take the low bits of the fill value.
|
|
*
|
|
* The defaults are:
|
|
* kRGBA_F16_SkColorType: Transparent or Black, depending on the src alpha type
|
|
* kN32_SkColorType: Transparent or Black, depending on the src alpha type
|
|
* kRGB_565_SkColorType: Black
|
|
* kGray_8_SkColorType: Black
|
|
*/
|
|
virtual uint64_t onGetFillValue(const SkImageInfo& dstInfo) const;
|
|
|
|
/**
|
|
* Get method for the input stream
|
|
*/
|
|
SkStream* stream() {
|
|
return fStream.get();
|
|
}
|
|
|
|
/**
|
|
* The remaining functions revolve around decoding scanlines.
|
|
*/
|
|
|
|
/**
|
|
* Most images types will be kTopDown and will not need to override this function.
|
|
*/
|
|
virtual SkScanlineOrder onGetScanlineOrder() const { return kTopDown_SkScanlineOrder; }
|
|
|
|
const SkImageInfo& dstInfo() const { return fDstInfo; }
|
|
|
|
const Options& options() const { return fOptions; }
|
|
|
|
/**
|
|
* Returns the number of scanlines that have been decoded so far.
|
|
* This is unaffected by the SkScanlineOrder.
|
|
*
|
|
* Returns -1 if we have not started a scanline decode.
|
|
*/
|
|
int currScanline() const { return fCurrScanline; }
|
|
|
|
virtual int onOutputScanline(int inputScanline) const;
|
|
|
|
bool initializeColorXform(const SkImageInfo& dstInfo,
|
|
SkTransferFunctionBehavior premulBehavior);
|
|
void applyColorXform(void* dst, const void* src, int count, SkAlphaType) const;
|
|
void applyColorXform(void* dst, const void* src, int count) const;
|
|
|
|
SkColorSpaceXform* colorXform() const { return fColorXform.get(); }
|
|
bool xformOnDecode() const { return fXformOnDecode; }
|
|
|
|
virtual int onGetFrameCount() {
|
|
return 1;
|
|
}
|
|
|
|
virtual bool onGetFrameInfo(int, FrameInfo*) const {
|
|
return false;
|
|
}
|
|
|
|
virtual int onGetRepetitionCount() {
|
|
return 0;
|
|
}
|
|
|
|
private:
|
|
const SkEncodedInfo fEncodedInfo;
|
|
const SkImageInfo fSrcInfo;
|
|
const XformFormat fSrcXformFormat;
|
|
std::unique_ptr<SkStream> fStream;
|
|
bool fNeedsRewind;
|
|
const Origin fOrigin;
|
|
|
|
SkImageInfo fDstInfo;
|
|
Options fOptions;
|
|
XformFormat fDstXformFormat; // Based on fDstInfo.
|
|
std::unique_ptr<SkColorSpaceXform> fColorXform;
|
|
bool fXformOnDecode;
|
|
|
|
// Only meaningful during scanline decodes.
|
|
int fCurrScanline;
|
|
|
|
bool fStartedIncrementalDecode;
|
|
|
|
/**
|
|
* Return whether these dimensions are supported as a scale.
|
|
*
|
|
* The codec may choose to cache the information about scale and subset.
|
|
* Either way, the same information will be passed to onGetPixels/onStart
|
|
* on success.
|
|
*
|
|
* This must return true for a size returned from getScaledDimensions.
|
|
*/
|
|
bool dimensionsSupported(const SkISize& dim) {
|
|
return dim == fSrcInfo.dimensions() || this->onDimensionsSupported(dim);
|
|
}
|
|
|
|
/**
|
|
* For multi-framed images, return the object with information about the frames.
|
|
*/
|
|
virtual const SkFrameHolder* getFrameHolder() const {
|
|
return nullptr;
|
|
}
|
|
|
|
/**
|
|
* Check for a valid Options.fFrameIndex, and decode prior frames if necessary.
|
|
*/
|
|
Result handleFrameIndex(const SkImageInfo&, void* pixels, size_t rowBytes, const Options&);
|
|
|
|
// Methods for scanline decoding.
|
|
virtual Result onStartScanlineDecode(const SkImageInfo& /*dstInfo*/,
|
|
const Options& /*options*/) {
|
|
return kUnimplemented;
|
|
}
|
|
|
|
virtual Result onStartIncrementalDecode(const SkImageInfo& /*dstInfo*/, void*, size_t,
|
|
const Options&) {
|
|
return kUnimplemented;
|
|
}
|
|
|
|
virtual Result onIncrementalDecode(int*) {
|
|
return kUnimplemented;
|
|
}
|
|
|
|
|
|
virtual bool onSkipScanlines(int /*countLines*/) { return false; }
|
|
|
|
virtual int onGetScanlines(void* /*dst*/, int /*countLines*/, size_t /*rowBytes*/) { return 0; }
|
|
|
|
/**
|
|
* On an incomplete decode, getPixels() and getScanlines() will call this function
|
|
* to fill any uinitialized memory.
|
|
*
|
|
* @param dstInfo Contains the destination color type
|
|
* Contains the destination alpha type
|
|
* Contains the destination width
|
|
* The height stored in this info is unused
|
|
* @param dst Pointer to the start of destination pixel memory
|
|
* @param rowBytes Stride length in destination pixel memory
|
|
* @param zeroInit Indicates if memory is zero initialized
|
|
* @param linesRequested Number of lines that the client requested
|
|
* @param linesDecoded Number of lines that were successfully decoded
|
|
*/
|
|
void fillIncompleteImage(const SkImageInfo& dstInfo, void* dst, size_t rowBytes,
|
|
ZeroInitialized zeroInit, int linesRequested, int linesDecoded);
|
|
|
|
/**
|
|
* Return an object which will allow forcing scanline decodes to sample in X.
|
|
*
|
|
* May create a sampler, if one is not currently being used. Otherwise, does
|
|
* not affect ownership.
|
|
*
|
|
* Only valid during scanline decoding or incremental decoding.
|
|
*/
|
|
virtual SkSampler* getSampler(bool /*createIfNecessary*/) { return nullptr; }
|
|
|
|
friend class DM::CodecSrc; // for fillIncompleteImage
|
|
friend class SkSampledCodec;
|
|
friend class SkIcoCodec;
|
|
};
|
|
#endif // SkCodec_DEFINED
|