2 * Copyright (c) 2020 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/internal/legacy/tizen/platform-capabilities.h>
27 #include <dali/devel-api/adaptor-framework/pixel-buffer.h>
31 namespace TizenPlatform
37 // simple class to enforce clean-up of PNG structures
40 auto_png(png_structp& _png, png_infop& _info)
50 png_destroy_read_struct(&png, &info, NULL);
56 }; // struct auto_png;
58 bool LoadPngHeader(FILE *fp, unsigned int &width, unsigned int &height, png_structp &png, png_infop &info)
60 png_byte header[8] = { 0 };
62 // Check header to see if it is a PNG file
63 size_t size = fread(header, 1, 8, fp);
69 if(png_sig_cmp(header, 0, 8))
74 png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
78 DALI_LOG_WARNING("Can't create PNG read structure\n");
82 info = png_create_info_struct(png);
85 DALI_LOG_WARNING("png_create_info_struct failed\n");
91 if(setjmp(png_jmpbuf(png)))
93 DALI_LOG_WARNING("error during png_init_io\n");
98 png_set_sig_bytes(png, 8);
101 png_read_info(png, info);
104 width = png_get_image_width(png, info);
105 height = png_get_image_height(png, info);
110 } // namespace - anonymous
112 bool LoadPngHeader( const Dali::ImageLoader::Input& input, unsigned int& width, unsigned int& height )
114 png_structp png = NULL;
115 png_infop info = NULL;
116 auto_png autoPng(png, info);
118 bool success = LoadPngHeader( input.file, width, height, png, info );
123 bool LoadBitmapFromPng( const Dali::ImageLoader::Input& input, Dali::Devel::PixelBuffer& bitmap )
125 png_structp png = NULL;
126 png_infop info = NULL;
127 auto_png autoPng(png, info);
129 /// @todo: consider parameters
131 unsigned int width, height;
133 unsigned int bpp = 0; // bytes per pixel
136 // Load info from the header
137 if( !LoadPngHeader( input.file, width, height, png, info ) )
142 Pixel::Format pixelFormat = Pixel::RGBA8888;
144 // decide pixel format
145 unsigned int colordepth = png_get_bit_depth(png, info);
147 // Ask PNGLib to convert high precision images into something we can use:
148 if (colordepth == 16)
150 png_set_strip_16(png);
154 png_byte colortype = png_get_color_type(png, info);
156 if( colortype == PNG_COLOR_TYPE_GRAY ||
157 colortype == PNG_COLOR_TYPE_GRAY_ALPHA )
159 if( colortype == PNG_COLOR_TYPE_GRAY )
161 pixelFormat = Pixel::L8;
162 if( png_get_valid(png, info, PNG_INFO_tRNS) )
164 colortype = PNG_COLOR_TYPE_GRAY_ALPHA;
165 /* expand transparency entry -> alpha channel if present */
166 png_set_tRNS_to_alpha(png);
167 pixelFormat = Pixel::LA88;
172 pixelFormat = Pixel::LA88;
177 /* expand gray (w/reduced bits) -> 8-bit RGB if necessary */
178 png_set_expand_gray_1_2_4_to_8(png);
179 /* pack all pixels to byte boundaries */
180 png_set_packing(png);
184 else if(colortype == PNG_COLOR_TYPE_RGB )
190 pixelFormat = Pixel::RGB888;
194 case 5: /// @todo is this correct for RGB16 5-6-5 ?
196 pixelFormat = Pixel::RGB565;
206 else if(colortype == PNG_COLOR_TYPE_RGBA)
212 pixelFormat = Pixel::RGBA8888;
222 else if(colortype == PNG_COLOR_TYPE_PALETTE)
228 pixelFormat = Pixel::LA88;
237 /* Expand paletted or RGB images with transparency to full alpha channels
238 * so the data will be available as RGBA quartets. PNG_INFO_tRNS = 0x10
240 if(png_get_valid(png, info, PNG_INFO_tRNS) == 0x10)
242 pixelFormat = Pixel::RGBA8888;
247 pixelFormat = Pixel::RGB888;
248 png_set_packing(png);
249 png_set_packswap(png);
250 png_set_palette_to_rgb(png);
264 DALI_LOG_WARNING( "Unsupported png format\n" );
269 bpp = Pixel::GetBytesPerPixel(pixelFormat);
271 png_read_update_info(png, info);
273 if(setjmp(png_jmpbuf(png)))
275 DALI_LOG_WARNING("error during png_read_image\n");
279 unsigned int rowBytes = png_get_rowbytes(png, info);
281 unsigned int bufferWidth = GetTextureDimension(width);
282 unsigned int bufferHeight = GetTextureDimension(height);
283 unsigned int stride = bufferWidth*bpp;
285 // not sure if this ever happens
286 if( rowBytes > stride )
288 stride = GetTextureDimension(rowBytes);
290 bpp = stride / bufferWidth;
294 pixelFormat = Pixel::RGB888;
297 pixelFormat = Pixel::RGBA8888;
305 // decode the whole image into bitmap buffer
306 auto pixels = (bitmap = Dali::Devel::PixelBuffer::New(bufferWidth, bufferHeight, pixelFormat)).GetBuffer();
308 DALI_ASSERT_DEBUG(pixels);
309 rows = reinterpret_cast< png_bytep* >( malloc(sizeof(png_bytep) * height) );
310 for(y=0; y<height; y++)
312 rows[y] = pixels + y * stride;
316 png_read_image(png, rows);
323 // simple class to enforce clean-up of PNG structures
326 AutoPngWrite(png_structp& _png, png_infop& _info)
336 png_destroy_write_struct(&png, &info);
342 }; // struct AutoPngWrite;
346 // Custom libpng write callbacks that buffer to a vector instead of a file:
349 * extern "C" linkage is used because this is a callback that we pass to a C
350 * library which is part of the underlying platform and so potentially compiled
351 * as C rather than C++.
352 * @see http://stackoverflow.com/a/2594222
354 extern "C" void WriteData(png_structp png_ptr, png_bytep data, png_size_t length)
356 DALI_ASSERT_DEBUG(png_ptr && data);
357 if(!png_ptr || !data)
361 // Make sure we don't try to propagate a C++ exception up the call stack of a pure C library:
364 // Recover our buffer for writing into:
365 Vector<unsigned char>* const encoded_img = static_cast< Vector<unsigned char>* >( png_get_io_ptr(png_ptr) );
368 const Vector<unsigned char>::SizeType bufferSize = encoded_img->Count();
369 encoded_img->Resize( bufferSize + length ); //< Can throw OOM.
370 unsigned char* const bufferBack = encoded_img->Begin() + bufferSize;
371 memcpy(bufferBack, data, length);
375 DALI_LOG_ERROR("PNG buffer for write to memory was passed from libpng as null.\n");
380 DALI_LOG_ERROR("C++ Exception caught\n");
384 /** Override the flush with a NOP to prevent libpng trying cstdlib file io. */
385 extern "C" void FlushData(png_structp png_ptr)
388 Debug::LogMessage(Debug::DebugInfo, "PNG Flush");
389 #endif // DEBUG_ENABLED
394 * Potential improvements:
395 * 1. Detect <= 256 colours and write in palette mode.
396 * 2. Detect grayscale (will early-out quickly for colour images).
397 * 3. Store colour space / gamma correction info related to the device screen?
398 * http://www.libpng.org/pub/png/book/chapter10.html
399 * 4. Refactor with callers to write straight through to disk and save keeping a big buffer around.
400 * 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)>.
401 * 6. Set the modification time with png_set_tIME(png_ptr, info_ptr, mod_time);
402 * 7. If caller asks for no compression, bypass libpng and blat raw data to
403 * disk, topped and tailed with header/tail blocks.
405 bool EncodeToPng( const unsigned char* const pixelBuffer, Vector<unsigned char>& encodedPixels, std::size_t width, std::size_t height, Pixel::Format pixelFormat )
407 // Translate pixel format enum:
408 int pngPixelFormat = -1;
409 unsigned pixelBytes = 0;
410 bool rgbaOrder = true;
412 // Account for RGB versus BGR and presence of alpha in input pixels:
413 switch( pixelFormat )
417 pngPixelFormat = PNG_COLOR_TYPE_RGB;
421 case Pixel::BGRA8888:
424 ///! No break: fall through:
426 case Pixel::RGBA8888:
428 pngPixelFormat = PNG_COLOR_TYPE_RGB_ALPHA;
434 DALI_LOG_ERROR( "Unsupported pixel format for encoding to PNG.\n" );
439 const int interlace = PNG_INTERLACE_NONE;
441 png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
446 /* Allocate/initialize the image information data. REQUIRED */
447 png_infop info_ptr = png_create_info_struct( png_ptr );
450 png_destroy_write_struct(&png_ptr, NULL);
454 /* Set error handling. REQUIRED if you aren't supplying your own
455 * error handling functions in the png_create_write_struct() call.
457 if(setjmp(png_jmpbuf(png_ptr)))
459 png_destroy_write_struct(&png_ptr, &info_ptr);
463 // Since we are going to write to memory instead of a file, lets provide
464 // libpng with a custom write function and ask it to pass back our
465 // Vector buffer each time it calls back to flush data to "file":
466 png_set_write_fn(png_ptr, &encodedPixels, WriteData, FlushData);
468 // png_set_compression_level( png_ptr, Z_BEST_COMPRESSION);
469 png_set_compression_level(png_ptr, Z_BEST_SPEED);
470 // png_set_compression_level( png_ptr, Z_NO_COMPRESSION); //! We could just generate png directly without libpng in this case.
472 // Explicitly limit the number of filters used per scanline to speed us up:
473 // png_set_filter(png_ptr, 0, PNG_FILTER_NONE); ///!ToDo: Try this once baseline profile is in place.
477 // PNG_FILTER_PAETH |
479 // Play with Zlib parameters in optimisation phase:
480 // png_set_compression_mem_level(png_ptr, 8);
481 // png_set_compression_strategy(png_ptr,
482 // Z_DEFAULT_STRATEGY);
483 // png_set_compression_window_bits(png_ptr, 15);
484 // png_set_compression_method(png_ptr, 8);
485 // png_set_compression_buffer_size(png_ptr, 8192)
487 // Let lib_png know if the pixel bytes are in BGR(A) order:
490 png_set_bgr( png_ptr );
493 // Set the image information:
494 png_set_IHDR(png_ptr, info_ptr, width, height, 8,
495 pngPixelFormat, interlace,
496 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
498 // Start to output the PNG data to our buffer:
499 png_write_info(png_ptr, info_ptr);
502 const unsigned row_step = width * pixelBytes;
503 png_bytep row_ptr = const_cast<png_bytep>(pixelBuffer);
504 const png_bytep row_end = row_ptr + height * row_step;
505 for(; row_ptr < row_end; row_ptr += row_step)
507 png_write_row(png_ptr, row_ptr);
510 /* It is REQUIRED to call this to finish writing the rest of the file */
511 png_write_end(png_ptr, info_ptr);
512 /* Clean up after the write, and free any memory allocated */
513 png_destroy_write_struct(&png_ptr, &info_ptr);
517 } // namespace TizenPlatform