Index: gfx/codec/png_codec.cc |
=================================================================== |
--- gfx/codec/png_codec.cc (revision 73487) |
+++ gfx/codec/png_codec.cc (working copy) |
@@ -1,699 +0,0 @@ |
-// Copyright (c) 2009 The Chromium Authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#include "gfx/codec/png_codec.h" |
- |
-#include "base/logging.h" |
-#include "base/scoped_ptr.h" |
-#include "third_party/skia/include/core/SkBitmap.h" |
-#include "third_party/skia/include/core/SkUnPreMultiply.h" |
-#include "third_party/skia/include/core/SkColorPriv.h" |
- |
-extern "C" { |
-#if defined(USE_SYSTEM_LIBPNG) |
-#include <png.h> |
-#else |
-#include "third_party/libpng/png.h" |
-#endif |
-} |
- |
-namespace gfx { |
- |
-namespace { |
- |
-// Converts BGRA->RGBA and RGBA->BGRA. |
-void ConvertBetweenBGRAandRGBA(const unsigned char* input, int pixel_width, |
- unsigned char* output, bool* is_opaque) { |
- for (int x = 0; x < pixel_width; x++) { |
- const unsigned char* pixel_in = &input[x * 4]; |
- unsigned char* pixel_out = &output[x * 4]; |
- pixel_out[0] = pixel_in[2]; |
- pixel_out[1] = pixel_in[1]; |
- pixel_out[2] = pixel_in[0]; |
- pixel_out[3] = pixel_in[3]; |
- } |
-} |
- |
-void ConvertRGBAtoRGB(const unsigned char* rgba, int pixel_width, |
- unsigned char* rgb, bool* is_opaque) { |
- for (int x = 0; x < pixel_width; x++) { |
- const unsigned char* pixel_in = &rgba[x * 4]; |
- unsigned char* pixel_out = &rgb[x * 3]; |
- pixel_out[0] = pixel_in[0]; |
- pixel_out[1] = pixel_in[1]; |
- pixel_out[2] = pixel_in[2]; |
- } |
-} |
- |
-void ConvertRGBtoSkia(const unsigned char* rgb, int pixel_width, |
- unsigned char* rgba, bool* is_opaque) { |
- for (int x = 0; x < pixel_width; x++) { |
- const unsigned char* pixel_in = &rgb[x * 3]; |
- uint32_t* pixel_out = reinterpret_cast<uint32_t*>(&rgba[x * 4]); |
- *pixel_out = SkPackARGB32(0xFF, pixel_in[0], pixel_in[1], pixel_in[2]); |
- } |
-} |
- |
-void ConvertRGBAtoSkia(const unsigned char* rgb, int pixel_width, |
- unsigned char* rgba, bool* is_opaque) { |
- int total_length = pixel_width * 4; |
- for (int x = 0; x < total_length; x += 4) { |
- const unsigned char* pixel_in = &rgb[x]; |
- uint32_t* pixel_out = reinterpret_cast<uint32_t*>(&rgba[x]); |
- |
- unsigned char alpha = pixel_in[3]; |
- if (alpha != 255) { |
- *is_opaque = false; |
- *pixel_out = SkPreMultiplyARGB(alpha, |
- pixel_in[0], pixel_in[1], pixel_in[2]); |
- } else { |
- *pixel_out = SkPackARGB32(alpha, |
- pixel_in[0], pixel_in[1], pixel_in[2]); |
- } |
- } |
-} |
- |
-void ConvertSkiatoRGB(const unsigned char* skia, int pixel_width, |
- unsigned char* rgb, bool* is_opaque) { |
- for (int x = 0; x < pixel_width; x++) { |
- const uint32_t pixel_in = *reinterpret_cast<const uint32_t*>(&skia[x * 4]); |
- unsigned char* pixel_out = &rgb[x * 3]; |
- |
- int alpha = SkGetPackedA32(pixel_in); |
- if (alpha != 0 && alpha != 255) { |
- SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(pixel_in); |
- pixel_out[0] = SkColorGetR(unmultiplied); |
- pixel_out[1] = SkColorGetG(unmultiplied); |
- pixel_out[2] = SkColorGetB(unmultiplied); |
- } else { |
- pixel_out[0] = SkGetPackedR32(pixel_in); |
- pixel_out[1] = SkGetPackedG32(pixel_in); |
- pixel_out[2] = SkGetPackedB32(pixel_in); |
- } |
- } |
-} |
- |
-void ConvertSkiatoRGBA(const unsigned char* skia, int pixel_width, |
- unsigned char* rgba, bool* is_opaque) { |
- int total_length = pixel_width * 4; |
- for (int i = 0; i < total_length; i += 4) { |
- const uint32_t pixel_in = *reinterpret_cast<const uint32_t*>(&skia[i]); |
- |
- // Pack the components here. |
- int alpha = SkGetPackedA32(pixel_in); |
- if (alpha != 0 && alpha != 255) { |
- SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(pixel_in); |
- rgba[i + 0] = SkColorGetR(unmultiplied); |
- rgba[i + 1] = SkColorGetG(unmultiplied); |
- rgba[i + 2] = SkColorGetB(unmultiplied); |
- rgba[i + 3] = alpha; |
- } else { |
- rgba[i + 0] = SkGetPackedR32(pixel_in); |
- rgba[i + 1] = SkGetPackedG32(pixel_in); |
- rgba[i + 2] = SkGetPackedB32(pixel_in); |
- rgba[i + 3] = alpha; |
- } |
- } |
-} |
- |
-} // namespace |
- |
-// Decoder -------------------------------------------------------------------- |
-// |
-// This code is based on WebKit libpng interface (PNGImageDecoder), which is |
-// in turn based on the Mozilla png decoder. |
- |
-namespace { |
- |
-// Gamma constants: We assume we're on Windows which uses a gamma of 2.2. |
-const double kMaxGamma = 21474.83; // Maximum gamma accepted by png library. |
-const double kDefaultGamma = 2.2; |
-const double kInverseGamma = 1.0 / kDefaultGamma; |
- |
-class PngDecoderState { |
- public: |
- // Output is a vector<unsigned char>. |
- PngDecoderState(PNGCodec::ColorFormat ofmt, std::vector<unsigned char>* o) |
- : output_format(ofmt), |
- output_channels(0), |
- bitmap(NULL), |
- is_opaque(true), |
- output(o), |
- row_converter(NULL), |
- width(0), |
- height(0), |
- done(false) { |
- } |
- |
- // Output is an SkBitmap. |
- explicit PngDecoderState(SkBitmap* skbitmap) |
- : output_format(PNGCodec::FORMAT_SkBitmap), |
- output_channels(0), |
- bitmap(skbitmap), |
- is_opaque(true), |
- output(NULL), |
- row_converter(NULL), |
- width(0), |
- height(0), |
- done(false) { |
- } |
- |
- PNGCodec::ColorFormat output_format; |
- int output_channels; |
- |
- // An incoming SkBitmap to write to. If NULL, we write to output instead. |
- SkBitmap* bitmap; |
- |
- // Used during the reading of an SkBitmap. Defaults to true until we see a |
- // pixel with anything other than an alpha of 255. |
- bool is_opaque; |
- |
- // The other way to decode output, where we write into an intermediary buffer |
- // instead of directly to an SkBitmap. |
- std::vector<unsigned char>* output; |
- |
- // Called to convert a row from the library to the correct output format. |
- // When NULL, no conversion is necessary. |
- void (*row_converter)(const unsigned char* in, int w, unsigned char* out, |
- bool* is_opaque); |
- |
- // Size of the image, set in the info callback. |
- int width; |
- int height; |
- |
- // Set to true when we've found the end of the data. |
- bool done; |
- |
- private: |
- DISALLOW_COPY_AND_ASSIGN(PngDecoderState); |
-}; |
- |
-void ConvertRGBtoRGBA(const unsigned char* rgb, int pixel_width, |
- unsigned char* rgba, bool* is_opaque) { |
- for (int x = 0; x < pixel_width; x++) { |
- const unsigned char* pixel_in = &rgb[x * 3]; |
- unsigned char* pixel_out = &rgba[x * 4]; |
- pixel_out[0] = pixel_in[0]; |
- pixel_out[1] = pixel_in[1]; |
- pixel_out[2] = pixel_in[2]; |
- pixel_out[3] = 0xff; |
- } |
-} |
- |
-void ConvertRGBtoBGRA(const unsigned char* rgb, int pixel_width, |
- unsigned char* bgra, bool* is_opaque) { |
- for (int x = 0; x < pixel_width; x++) { |
- const unsigned char* pixel_in = &rgb[x * 3]; |
- unsigned char* pixel_out = &bgra[x * 4]; |
- pixel_out[0] = pixel_in[2]; |
- pixel_out[1] = pixel_in[1]; |
- pixel_out[2] = pixel_in[0]; |
- pixel_out[3] = 0xff; |
- } |
-} |
- |
-// Called when the png header has been read. This code is based on the WebKit |
-// PNGImageDecoder |
-void DecodeInfoCallback(png_struct* png_ptr, png_info* info_ptr) { |
- PngDecoderState* state = static_cast<PngDecoderState*>( |
- png_get_progressive_ptr(png_ptr)); |
- |
- int bit_depth, color_type, interlace_type, compression_type; |
- int filter_type, channels; |
- png_uint_32 w, h; |
- png_get_IHDR(png_ptr, info_ptr, &w, &h, &bit_depth, &color_type, |
- &interlace_type, &compression_type, &filter_type); |
- |
- // Bounds check. When the image is unreasonably big, we'll error out and |
- // end up back at the setjmp call when we set up decoding. "Unreasonably big" |
- // means "big enough that w * h * 32bpp might overflow an int"; we choose this |
- // threshold to match WebKit and because a number of places in code assume |
- // that an image's size (in bytes) fits in a (signed) int. |
- unsigned long long total_size = |
- static_cast<unsigned long long>(w) * static_cast<unsigned long long>(h); |
- if (total_size > ((1 << 29) - 1)) |
- longjmp(png_jmpbuf(png_ptr), 1); |
- state->width = static_cast<int>(w); |
- state->height = static_cast<int>(h); |
- |
- // Expand to ensure we use 24-bit for RGB and 32-bit for RGBA. |
- if (color_type == PNG_COLOR_TYPE_PALETTE || |
- (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)) |
- png_set_expand(png_ptr); |
- |
- // Transparency for paletted images. |
- if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) |
- png_set_expand(png_ptr); |
- |
- // Convert 16-bit to 8-bit. |
- if (bit_depth == 16) |
- png_set_strip_16(png_ptr); |
- |
- // Expand grayscale to RGB. |
- if (color_type == PNG_COLOR_TYPE_GRAY || |
- color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
- png_set_gray_to_rgb(png_ptr); |
- |
- // Deal with gamma and keep it under our control. |
- double gamma; |
- if (png_get_gAMA(png_ptr, info_ptr, &gamma)) { |
- if (gamma <= 0.0 || gamma > kMaxGamma) { |
- gamma = kInverseGamma; |
- png_set_gAMA(png_ptr, info_ptr, gamma); |
- } |
- png_set_gamma(png_ptr, kDefaultGamma, gamma); |
- } else { |
- png_set_gamma(png_ptr, kDefaultGamma, kInverseGamma); |
- } |
- |
- // Tell libpng to send us rows for interlaced pngs. |
- if (interlace_type == PNG_INTERLACE_ADAM7) |
- png_set_interlace_handling(png_ptr); |
- |
- // Update our info now |
- png_read_update_info(png_ptr, info_ptr); |
- channels = png_get_channels(png_ptr, info_ptr); |
- |
- // Pick our row format converter necessary for this data. |
- if (channels == 3) { |
- switch (state->output_format) { |
- case PNGCodec::FORMAT_RGB: |
- state->row_converter = NULL; // no conversion necessary |
- state->output_channels = 3; |
- break; |
- case PNGCodec::FORMAT_RGBA: |
- state->row_converter = &ConvertRGBtoRGBA; |
- state->output_channels = 4; |
- break; |
- case PNGCodec::FORMAT_BGRA: |
- state->row_converter = &ConvertRGBtoBGRA; |
- state->output_channels = 4; |
- break; |
- case PNGCodec::FORMAT_SkBitmap: |
- state->row_converter = &ConvertRGBtoSkia; |
- state->output_channels = 4; |
- break; |
- default: |
- NOTREACHED() << "Unknown output format"; |
- break; |
- } |
- } else if (channels == 4) { |
- switch (state->output_format) { |
- case PNGCodec::FORMAT_RGB: |
- state->row_converter = &ConvertRGBAtoRGB; |
- state->output_channels = 3; |
- break; |
- case PNGCodec::FORMAT_RGBA: |
- state->row_converter = NULL; // no conversion necessary |
- state->output_channels = 4; |
- break; |
- case PNGCodec::FORMAT_BGRA: |
- state->row_converter = &ConvertBetweenBGRAandRGBA; |
- state->output_channels = 4; |
- break; |
- case PNGCodec::FORMAT_SkBitmap: |
- state->row_converter = &ConvertRGBAtoSkia; |
- state->output_channels = 4; |
- break; |
- default: |
- NOTREACHED() << "Unknown output format"; |
- break; |
- } |
- } else { |
- NOTREACHED() << "Unknown input channels"; |
- longjmp(png_jmpbuf(png_ptr), 1); |
- } |
- |
- if (state->bitmap) { |
- state->bitmap->setConfig(SkBitmap::kARGB_8888_Config, |
- state->width, state->height); |
- state->bitmap->allocPixels(); |
- } else if (state->output) { |
- state->output->resize( |
- state->width * state->output_channels * state->height); |
- } |
-} |
- |
-void DecodeRowCallback(png_struct* png_ptr, png_byte* new_row, |
- png_uint_32 row_num, int pass) { |
- PngDecoderState* state = static_cast<PngDecoderState*>( |
- png_get_progressive_ptr(png_ptr)); |
- |
- DCHECK(pass == 0) << "We didn't turn on interlace handling, but libpng is " |
- "giving us interlaced data."; |
- if (static_cast<int>(row_num) > state->height) { |
- NOTREACHED() << "Invalid row"; |
- return; |
- } |
- |
- unsigned char* base = NULL; |
- if (state->bitmap) |
- base = reinterpret_cast<unsigned char*>(state->bitmap->getAddr32(0, 0)); |
- else if (state->output) |
- base = &state->output->front(); |
- |
- unsigned char* dest = &base[state->width * state->output_channels * row_num]; |
- if (state->row_converter) |
- state->row_converter(new_row, state->width, dest, &state->is_opaque); |
- else |
- memcpy(dest, new_row, state->width * state->output_channels); |
-} |
- |
-void DecodeEndCallback(png_struct* png_ptr, png_info* info) { |
- PngDecoderState* state = static_cast<PngDecoderState*>( |
- png_get_progressive_ptr(png_ptr)); |
- |
- // Mark the image as complete, this will tell the Decode function that we |
- // have successfully found the end of the data. |
- state->done = true; |
-} |
- |
-// Automatically destroys the given read structs on destruction to make |
-// cleanup and error handling code cleaner. |
-class PngReadStructDestroyer { |
- public: |
- PngReadStructDestroyer(png_struct** ps, png_info** pi) : ps_(ps), pi_(pi) { |
- } |
- ~PngReadStructDestroyer() { |
- png_destroy_read_struct(ps_, pi_, NULL); |
- } |
- private: |
- png_struct** ps_; |
- png_info** pi_; |
-}; |
- |
-bool BuildPNGStruct(const unsigned char* input, size_t input_size, |
- png_struct** png_ptr, png_info** info_ptr) { |
- if (input_size < 8) |
- return false; // Input data too small to be a png |
- |
- // Have libpng check the signature, it likes the first 8 bytes. |
- if (png_sig_cmp(const_cast<unsigned char*>(input), 0, 8) != 0) |
- return false; |
- |
- *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); |
- if (!*png_ptr) |
- return false; |
- |
- *info_ptr = png_create_info_struct(*png_ptr); |
- if (!*info_ptr) { |
- png_destroy_read_struct(png_ptr, NULL, NULL); |
- return false; |
- } |
- |
- return true; |
-} |
- |
-} // namespace |
- |
-// static |
-bool PNGCodec::Decode(const unsigned char* input, size_t input_size, |
- ColorFormat format, std::vector<unsigned char>* output, |
- int* w, int* h) { |
- png_struct* png_ptr = NULL; |
- png_info* info_ptr = NULL; |
- if (!BuildPNGStruct(input, input_size, &png_ptr, &info_ptr)) |
- return false; |
- |
- PngReadStructDestroyer destroyer(&png_ptr, &info_ptr); |
- if (setjmp(png_jmpbuf(png_ptr))) { |
- // The destroyer will ensure that the structures are cleaned up in this |
- // case, even though we may get here as a jump from random parts of the |
- // PNG library called below. |
- return false; |
- } |
- |
- PngDecoderState state(format, output); |
- |
- png_set_progressive_read_fn(png_ptr, &state, &DecodeInfoCallback, |
- &DecodeRowCallback, &DecodeEndCallback); |
- png_process_data(png_ptr, |
- info_ptr, |
- const_cast<unsigned char*>(input), |
- input_size); |
- |
- if (!state.done) { |
- // Fed it all the data but the library didn't think we got all the data, so |
- // this file must be truncated. |
- output->clear(); |
- return false; |
- } |
- |
- *w = state.width; |
- *h = state.height; |
- return true; |
-} |
- |
-// static |
-bool PNGCodec::Decode(const unsigned char* input, size_t input_size, |
- SkBitmap* bitmap) { |
- DCHECK(bitmap); |
- png_struct* png_ptr = NULL; |
- png_info* info_ptr = NULL; |
- if (!BuildPNGStruct(input, input_size, &png_ptr, &info_ptr)) |
- return false; |
- |
- PngReadStructDestroyer destroyer(&png_ptr, &info_ptr); |
- if (setjmp(png_jmpbuf(png_ptr))) { |
- // The destroyer will ensure that the structures are cleaned up in this |
- // case, even though we may get here as a jump from random parts of the |
- // PNG library called below. |
- return false; |
- } |
- |
- PngDecoderState state(bitmap); |
- |
- png_set_progressive_read_fn(png_ptr, &state, &DecodeInfoCallback, |
- &DecodeRowCallback, &DecodeEndCallback); |
- png_process_data(png_ptr, |
- info_ptr, |
- const_cast<unsigned char*>(input), |
- input_size); |
- |
- if (!state.done) { |
- return false; |
- } |
- |
- // Set the bitmap's opaqueness based on what we saw. |
- bitmap->setIsOpaque(state.is_opaque); |
- |
- return true; |
-} |
- |
-// static |
-SkBitmap* PNGCodec::CreateSkBitmapFromBGRAFormat( |
- std::vector<unsigned char>& bgra, int width, int height) { |
- SkBitmap* bitmap = new SkBitmap(); |
- bitmap->setConfig(SkBitmap::kARGB_8888_Config, width, height); |
- bitmap->allocPixels(); |
- |
- bool opaque = false; |
- unsigned char* bitmap_data = |
- reinterpret_cast<unsigned char*>(bitmap->getAddr32(0, 0)); |
- for (int i = width * height * 4 - 4; i >= 0; i -= 4) { |
- unsigned char alpha = bgra[i + 3]; |
- if (!opaque && alpha != 255) { |
- opaque = false; |
- } |
- bitmap_data[i + 3] = alpha; |
- bitmap_data[i] = (bgra[i] * alpha) >> 8; |
- bitmap_data[i + 1] = (bgra[i + 1] * alpha) >> 8; |
- bitmap_data[i + 2] = (bgra[i + 2] * alpha) >> 8; |
- } |
- |
- bitmap->setIsOpaque(opaque); |
- return bitmap; |
-} |
- |
-// Encoder -------------------------------------------------------------------- |
-// |
-// This section of the code is based on nsPNGEncoder.cpp in Mozilla |
-// (Copyright 2005 Google Inc.) |
- |
-namespace { |
- |
-// Passed around as the io_ptr in the png structs so our callbacks know where |
-// to write data. |
-struct PngEncoderState { |
- explicit PngEncoderState(std::vector<unsigned char>* o) : out(o) {} |
- std::vector<unsigned char>* out; |
-}; |
- |
-// Called by libpng to flush its internal buffer to ours. |
-void EncoderWriteCallback(png_structp png, png_bytep data, png_size_t size) { |
- PngEncoderState* state = static_cast<PngEncoderState*>(png_get_io_ptr(png)); |
- DCHECK(state->out); |
- |
- size_t old_size = state->out->size(); |
- state->out->resize(old_size + size); |
- memcpy(&(*state->out)[old_size], data, size); |
-} |
- |
-void FakeFlushCallback(png_structp png) { |
- // We don't need to perform any flushing since we aren't doing real IO, but |
- // we're required to provide this function by libpng. |
-} |
- |
-void ConvertBGRAtoRGB(const unsigned char* bgra, int pixel_width, |
- unsigned char* rgb, bool* is_opaque) { |
- for (int x = 0; x < pixel_width; x++) { |
- const unsigned char* pixel_in = &bgra[x * 4]; |
- unsigned char* pixel_out = &rgb[x * 3]; |
- pixel_out[0] = pixel_in[2]; |
- pixel_out[1] = pixel_in[1]; |
- pixel_out[2] = pixel_in[0]; |
- } |
-} |
- |
-// The type of functions usable for converting between pixel formats. |
-typedef void (*FormatConverter)(const unsigned char* in, int w, |
- unsigned char* out, bool* is_opaque); |
- |
-// libpng uses a wacky setjmp-based API, which makes the compiler nervous. |
-// We constrain all of the calls we make to libpng where the setjmp() is in |
-// place to this function. |
-// Returns true on success. |
-bool DoLibpngWrite(png_struct* png_ptr, png_info* info_ptr, |
- PngEncoderState* state, |
- int width, int height, int row_byte_width, |
- const unsigned char* input, |
- int png_output_color_type, int output_color_components, |
- FormatConverter converter) { |
- // Make sure to not declare any locals here -- locals in the presence |
- // of setjmp() in C++ code makes gcc complain. |
- |
- if (setjmp(png_jmpbuf(png_ptr))) |
- return false; |
- |
- // Set our callback for libpng to give us the data. |
- png_set_write_fn(png_ptr, state, EncoderWriteCallback, FakeFlushCallback); |
- |
- png_set_IHDR(png_ptr, info_ptr, width, height, 8, png_output_color_type, |
- PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, |
- PNG_FILTER_TYPE_DEFAULT); |
- png_write_info(png_ptr, info_ptr); |
- |
- if (!converter) { |
- // No conversion needed, give the data directly to libpng. |
- for (int y = 0; y < height; y ++) { |
- png_write_row(png_ptr, |
- const_cast<unsigned char*>(&input[y * row_byte_width])); |
- } |
- } else { |
- // Needs conversion using a separate buffer. |
- unsigned char* row = new unsigned char[width * output_color_components]; |
- for (int y = 0; y < height; y ++) { |
- converter(&input[y * row_byte_width], width, row, NULL); |
- png_write_row(png_ptr, row); |
- } |
- delete[] row; |
- } |
- |
- png_write_end(png_ptr, info_ptr); |
- return true; |
-} |
- |
-} // namespace |
- |
-// static |
-bool PNGCodec::Encode(const unsigned char* input, ColorFormat format, |
- int w, int h, int row_byte_width, |
- bool discard_transparency, |
- std::vector<unsigned char>* output) { |
- // Run to convert an input row into the output row format, NULL means no |
- // conversion is necessary. |
- FormatConverter converter = NULL; |
- |
- int input_color_components, output_color_components; |
- int png_output_color_type; |
- switch (format) { |
- case FORMAT_RGB: |
- input_color_components = 3; |
- output_color_components = 3; |
- png_output_color_type = PNG_COLOR_TYPE_RGB; |
- discard_transparency = false; |
- break; |
- |
- case FORMAT_RGBA: |
- input_color_components = 4; |
- if (discard_transparency) { |
- output_color_components = 3; |
- png_output_color_type = PNG_COLOR_TYPE_RGB; |
- converter = ConvertRGBAtoRGB; |
- } else { |
- output_color_components = 4; |
- png_output_color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
- converter = NULL; |
- } |
- break; |
- |
- case FORMAT_BGRA: |
- input_color_components = 4; |
- if (discard_transparency) { |
- output_color_components = 3; |
- png_output_color_type = PNG_COLOR_TYPE_RGB; |
- converter = ConvertBGRAtoRGB; |
- } else { |
- output_color_components = 4; |
- png_output_color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
- converter = ConvertBetweenBGRAandRGBA; |
- } |
- break; |
- |
- case FORMAT_SkBitmap: |
- input_color_components = 4; |
- if (discard_transparency) { |
- output_color_components = 3; |
- png_output_color_type = PNG_COLOR_TYPE_RGB; |
- converter = ConvertSkiatoRGB; |
- } else { |
- output_color_components = 4; |
- png_output_color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
- converter = ConvertSkiatoRGBA; |
- } |
- break; |
- |
- default: |
- NOTREACHED() << "Unknown pixel format"; |
- return false; |
- } |
- |
- // Row stride should be at least as long as the length of the data. |
- DCHECK(input_color_components * w <= row_byte_width); |
- |
- png_struct* png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, |
- NULL, NULL, NULL); |
- if (!png_ptr) |
- return false; |
- png_info* info_ptr = png_create_info_struct(png_ptr); |
- if (!info_ptr) { |
- png_destroy_write_struct(&png_ptr, NULL); |
- return false; |
- } |
- |
- PngEncoderState state(output); |
- bool success = DoLibpngWrite(png_ptr, info_ptr, &state, |
- w, h, row_byte_width, input, |
- png_output_color_type, output_color_components, |
- converter); |
- png_destroy_write_struct(&png_ptr, &info_ptr); |
- |
- return success; |
-} |
- |
-// static |
-bool PNGCodec::EncodeBGRASkBitmap(const SkBitmap& input, |
- bool discard_transparency, |
- std::vector<unsigned char>* output) { |
- static const int bbp = 4; |
- |
- SkAutoLockPixels lock_input(input); |
- DCHECK(input.empty() || input.bytesPerPixel() == bbp); |
- |
- return Encode(reinterpret_cast<unsigned char*>(input.getAddr32(0, 0)), |
- FORMAT_SkBitmap, input.width(), input.height(), |
- input.width() * bbp, discard_transparency, output); |
-} |
- |
-} // namespace gfx |