2 * Copyright (c) 2017 Samsung Electronics Co., Ltd.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include <dali/internal/imaging/common/loader-png.h>
25 #include <dali/integration-api/debug.h>
26 #include <dali/public-api/images/image.h>
27 #include <dali/internal/legacy/tizen/platform-capabilities.h>
28 #include <dali/devel-api/adaptor-framework/pixel-buffer.h>
32 namespace TizenPlatform
38 // simple class to enforce clean-up of PNG structures
41 auto_png(png_structp& _png, png_infop& _info)
51 png_destroy_read_struct(&png, &info, NULL);
57 }; // struct auto_png;
59 bool LoadPngHeader(FILE *fp, unsigned int &width, unsigned int &height, png_structp &png, png_infop &info)
61 png_byte header[8] = { 0 };
63 // Check header to see if it is a PNG file
64 size_t size = fread(header, 1, 8, fp);
70 if(png_sig_cmp(header, 0, 8))
75 png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
79 DALI_LOG_WARNING("Can't create PNG read structure\n");
83 info = png_create_info_struct(png);
86 DALI_LOG_WARNING("png_create_info_struct failed\n");
92 if(setjmp(png_jmpbuf(png)))
94 DALI_LOG_WARNING("error during png_init_io\n");
99 png_set_sig_bytes(png, 8);
102 png_read_info(png, info);
105 width = png_get_image_width(png, info);
106 height = png_get_image_height(png, info);
111 } // namespace - anonymous
113 bool LoadPngHeader( const Dali::ImageLoader::Input& input, unsigned int& width, unsigned int& height )
115 png_structp png = NULL;
116 png_infop info = NULL;
117 auto_png autoPng(png, info);
119 bool success = LoadPngHeader( input.file, width, height, png, info );
124 bool LoadBitmapFromPng( const Dali::ImageLoader::Input& input, Dali::Devel::PixelBuffer& bitmap )
126 png_structp png = NULL;
127 png_infop info = NULL;
128 auto_png autoPng(png, info);
130 /// @todo: consider parameters
132 unsigned int width, height;
134 unsigned int bpp = 0; // bytes per pixel
137 // Load info from the header
138 if( !LoadPngHeader( input.file, width, height, png, info ) )
143 Pixel::Format pixelFormat = Pixel::RGBA8888;
145 // decide pixel format
146 unsigned int colordepth = png_get_bit_depth(png, info);
148 // Ask PNGLib to convert high precision images into something we can use:
149 if (colordepth == 16)
151 png_set_strip_16(png);
155 png_byte colortype = png_get_color_type(png, info);
157 if( colortype == PNG_COLOR_TYPE_GRAY ||
158 colortype == PNG_COLOR_TYPE_GRAY_ALPHA )
160 if( colortype == PNG_COLOR_TYPE_GRAY )
162 pixelFormat = Pixel::L8;
163 if( png_get_valid(png, info, PNG_INFO_tRNS) )
165 colortype = PNG_COLOR_TYPE_GRAY_ALPHA;
166 /* expand transparency entry -> alpha channel if present */
167 png_set_tRNS_to_alpha(png);
168 pixelFormat = Pixel::LA88;
173 pixelFormat = Pixel::LA88;
178 /* expand gray (w/reduced bits) -> 8-bit RGB if necessary */
179 png_set_expand_gray_1_2_4_to_8(png);
180 /* pack all pixels to byte boundaries */
181 png_set_packing(png);
185 else if(colortype == PNG_COLOR_TYPE_RGB )
191 pixelFormat = Pixel::RGB888;
195 case 5: /// @todo is this correct for RGB16 5-6-5 ?
197 pixelFormat = Pixel::RGB565;
207 else if(colortype == PNG_COLOR_TYPE_RGBA)
213 pixelFormat = Pixel::RGBA8888;
223 else if(colortype == PNG_COLOR_TYPE_PALETTE)
229 pixelFormat = Pixel::LA88;
238 /* Expand paletted or RGB images with transparency to full alpha channels
239 * so the data will be available as RGBA quartets. PNG_INFO_tRNS = 0x10
241 if(png_get_valid(png, info, PNG_INFO_tRNS) == 0x10)
243 pixelFormat = Pixel::RGBA8888;
248 pixelFormat = Pixel::RGB888;
249 png_set_packing(png);
250 png_set_packswap(png);
251 png_set_palette_to_rgb(png);
265 DALI_LOG_WARNING( "Unsupported png format\n" );
270 bpp = Pixel::GetBytesPerPixel(pixelFormat);
272 png_read_update_info(png, info);
274 if(setjmp(png_jmpbuf(png)))
276 DALI_LOG_WARNING("error during png_read_image\n");
280 unsigned int rowBytes = png_get_rowbytes(png, info);
282 unsigned int bufferWidth = GetTextureDimension(width);
283 unsigned int bufferHeight = GetTextureDimension(height);
284 unsigned int stride = bufferWidth*bpp;
286 // not sure if this ever happens
287 if( rowBytes > stride )
289 stride = GetTextureDimension(rowBytes);
291 bpp = stride / bufferWidth;
295 pixelFormat = Pixel::RGB888;
298 pixelFormat = Pixel::RGBA8888;
306 // decode the whole image into bitmap buffer
307 auto pixels = (bitmap = Dali::Devel::PixelBuffer::New(bufferWidth, bufferHeight, pixelFormat)).GetBuffer();
309 DALI_ASSERT_DEBUG(pixels);
310 rows = reinterpret_cast< png_bytep* >( malloc(sizeof(png_bytep) * height) );
311 for(y=0; y<height; y++)
313 rows[y] = pixels + y * stride;
317 png_read_image(png, rows);
324 // simple class to enforce clean-up of PNG structures
327 AutoPngWrite(png_structp& _png, png_infop& _info)
337 png_destroy_write_struct(&png, &info);
343 }; // struct AutoPngWrite;
347 // Custom libpng write callbacks that buffer to a vector instead of a file:
350 * extern "C" linkage is used because this is a callback that we pass to a C
351 * library which is part of the underlying platform and so potentially compiled
352 * as C rather than C++.
353 * @see http://stackoverflow.com/a/2594222
355 extern "C" void WriteData(png_structp png_ptr, png_bytep data, png_size_t length)
357 DALI_ASSERT_DEBUG(png_ptr && data);
358 if(!png_ptr || !data)
362 // Make sure we don't try to propagate a C++ exception up the call stack of a pure C library:
365 // Recover our buffer for writing into:
366 Vector<unsigned char>* const encoded_img = static_cast< Vector<unsigned char>* >( png_get_io_ptr(png_ptr) );
369 const Vector<unsigned char>::SizeType bufferSize = encoded_img->Count();
370 encoded_img->Resize( bufferSize + length ); //< Can throw OOM.
371 unsigned char* const bufferBack = encoded_img->Begin() + bufferSize;
372 memcpy(bufferBack, data, length);
376 DALI_LOG_ERROR("PNG buffer for write to memory was passed from libpng as null.\n");
381 DALI_LOG_ERROR("C++ Exception caught\n");
385 /** Override the flush with a NOP to prevent libpng trying cstdlib file io. */
386 extern "C" void FlushData(png_structp png_ptr)
389 Debug::LogMessage(Debug::DebugInfo, "PNG Flush");
390 #endif // DEBUG_ENABLED
395 * Potential improvements:
396 * 1. Detect <= 256 colours and write in palette mode.
397 * 2. Detect grayscale (will early-out quickly for colour images).
398 * 3. Store colour space / gamma correction info related to the device screen?
399 * http://www.libpng.org/pub/png/book/chapter10.html
400 * 4. Refactor with callers to write straight through to disk and save keeping a big buffer around.
401 * 5. Prealloc buffer (reserve) to input size / <A number greater than 2 (expexcted few realloc but without using lots of memory) | 1 (expected zero reallocs but using a lot of memory)>.
402 * 6. Set the modification time with png_set_tIME(png_ptr, info_ptr, mod_time);
403 * 7. If caller asks for no compression, bypass libpng and blat raw data to
404 * disk, topped and tailed with header/tail blocks.
406 bool EncodeToPng( const unsigned char* const pixelBuffer, Vector<unsigned char>& encodedPixels, std::size_t width, std::size_t height, Pixel::Format pixelFormat )
408 // Translate pixel format enum:
409 int pngPixelFormat = -1;
410 unsigned pixelBytes = 0;
411 bool rgbaOrder = true;
413 // Account for RGB versus BGR and presence of alpha in input pixels:
414 switch( pixelFormat )
418 pngPixelFormat = PNG_COLOR_TYPE_RGB;
422 case Pixel::BGRA8888:
425 ///! No break: fall through:
427 case Pixel::RGBA8888:
429 pngPixelFormat = PNG_COLOR_TYPE_RGB_ALPHA;
435 DALI_LOG_ERROR( "Unsupported pixel format for encoding to PNG.\n" );
440 const int interlace = PNG_INTERLACE_NONE;
442 png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
447 /* Allocate/initialize the image information data. REQUIRED */
448 png_infop info_ptr = png_create_info_struct( png_ptr );
451 png_destroy_write_struct(&png_ptr, NULL);
455 /* Set error handling. REQUIRED if you aren't supplying your own
456 * error handling functions in the png_create_write_struct() call.
458 if(setjmp(png_jmpbuf(png_ptr)))
460 png_destroy_write_struct(&png_ptr, &info_ptr);
464 // Since we are going to write to memory instead of a file, lets provide
465 // libpng with a custom write function and ask it to pass back our
466 // Vector buffer each time it calls back to flush data to "file":
467 png_set_write_fn(png_ptr, &encodedPixels, WriteData, FlushData);
469 // png_set_compression_level( png_ptr, Z_BEST_COMPRESSION);
470 png_set_compression_level(png_ptr, Z_BEST_SPEED);
471 // png_set_compression_level( png_ptr, Z_NO_COMPRESSION); //! We could just generate png directly without libpng in this case.
473 // Explicitly limit the number of filters used per scanline to speed us up:
474 // png_set_filter(png_ptr, 0, PNG_FILTER_NONE); ///!ToDo: Try this once baseline profile is in place.
478 // PNG_FILTER_PAETH |
480 // Play with Zlib parameters in optimisation phase:
481 // png_set_compression_mem_level(png_ptr, 8);
482 // png_set_compression_strategy(png_ptr,
483 // Z_DEFAULT_STRATEGY);
484 // png_set_compression_window_bits(png_ptr, 15);
485 // png_set_compression_method(png_ptr, 8);
486 // png_set_compression_buffer_size(png_ptr, 8192)
488 // Let lib_png know if the pixel bytes are in BGR(A) order:
491 png_set_bgr( png_ptr );
494 // Set the image information:
495 png_set_IHDR(png_ptr, info_ptr, width, height, 8,
496 pngPixelFormat, interlace,
497 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
499 // Start to output the PNG data to our buffer:
500 png_write_info(png_ptr, info_ptr);
503 const unsigned row_step = width * pixelBytes;
504 png_bytep row_ptr = const_cast<png_bytep>(pixelBuffer);
505 const png_bytep row_end = row_ptr + height * row_step;
506 for(; row_ptr < row_end; row_ptr += row_step)
508 png_write_row(png_ptr, row_ptr);
511 /* It is REQUIRED to call this to finish writing the rest of the file */
512 png_write_end(png_ptr, info_ptr);
513 /* Clean up after the write, and free any memory allocated */
514 png_destroy_write_struct(&png_ptr, &info_ptr);
518 } // namespace TizenPlatform