| 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
|
|
|