skia2/include/encode/SkWebpEncoder.h
Matt Sarett d5a16911bb Add support for webp lossless compression
Bug: 713862
Change-Id: I8dcc6506338f3c54fb14a78620e7daaadadfedde
Reviewed-on: https://skia-review.googlesource.com/17073
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>
2017-05-17 02:24:29 +00:00

56 lines
1.8 KiB
C++

/*
* Copyright 2017 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkWebpEncoder_DEFINED
#define SkWebpEncoder_DEFINED
#include "SkEncoder.h"
class SkWStream;
namespace SkWebpEncoder {
enum class SK_API Compression {
kLossy,
kLossless,
};
struct SK_API Options {
/**
* |fCompression| determines whether we will use webp lossy or lossless compression.
*
* |fQuality| must be in [0.0f, 100.0f].
* If |fCompression| is kLossy, |fQuality| corresponds to the visual quality of the
* encoding. Decreasing the quality will result in a smaller encoded image.
* If |fCompression| is kLossless, |fQuality| corresponds to the amount of effort
* put into the encoding. Lower values will compress faster into larger files,
* while larger values will compress slower into smaller files.
*
* This scheme is designed to match the libwebp API.
*/
Compression fCompression = Compression::kLossy;
float fQuality = 100.0f;
/**
* If the input is premultiplied, this controls the unpremultiplication behavior.
* The encoder can convert to linear before unpremultiplying or ignore the transfer
* function and unpremultiply the input as is.
*/
SkTransferFunctionBehavior fUnpremulBehavior = SkTransferFunctionBehavior::kRespect;
};
/**
* Encode the |src| pixels to the |dst| stream.
* |options| may be used to control the encoding behavior.
*
* Returns true on success. Returns false on an invalid or unsupported |src|.
*/
SK_API bool Encode(SkWStream* dst, const SkPixmap& src, const Options& options);
};
#endif