2 * Copyright (c) 2021 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/devel-api/adaptor-framework/pixel-buffer.h>
26 #include <dali/integration-api/debug.h>
27 #include <dali/internal/legacy/tizen/platform-capabilities.h>
31 namespace TizenPlatform
35 // simple class to enforce clean-up of PNG structures
38 auto_png(png_structp& _png, png_infop& _info)
48 png_destroy_read_struct(&png, &info, NULL);
54 }; // struct auto_png;
56 bool LoadPngHeader(FILE* fp, unsigned int& width, unsigned int& height, png_structp& png, png_infop& info)
58 png_byte header[8] = {0};
60 // Check header to see if it is a PNG file
61 size_t size = fread(header, 1, 8, fp);
67 if(png_sig_cmp(header, 0, 8))
72 png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
76 DALI_LOG_WARNING("Can't create PNG read structure\n");
80 info = png_create_info_struct(png);
83 DALI_LOG_WARNING("png_create_info_struct failed\n");
89 if(setjmp(png_jmpbuf(png)))
91 DALI_LOG_WARNING("error during png_init_io\n");
96 png_set_sig_bytes(png, 8);
99 png_read_info(png, info);
102 width = png_get_image_width(png, info);
103 height = png_get_image_height(png, info);
110 bool LoadPngHeader(const Dali::ImageLoader::Input& input, unsigned int& width, unsigned int& height)
112 png_structp png = NULL;
113 png_infop info = NULL;
114 auto_png autoPng(png, info);
116 bool success = LoadPngHeader(input.file, width, height, png, info);
121 bool LoadBitmapFromPng(const Dali::ImageLoader::Input& input, Dali::Devel::PixelBuffer& bitmap)
123 png_structp png = NULL;
124 png_infop info = NULL;
125 auto_png autoPng(png, info);
127 /// @todo: consider parameters
129 unsigned int width, height;
131 unsigned int bpp = 0; // bytes per pixel
134 // Load info from the header
135 if(!LoadPngHeader(input.file, width, height, png, info))
140 Pixel::Format pixelFormat = Pixel::RGBA8888;
142 // decide pixel format
143 unsigned int colordepth = png_get_bit_depth(png, info);
145 // Ask PNGLib to convert high precision images into something we can use:
148 png_set_strip_16(png);
152 png_byte colortype = png_get_color_type(png, info);
154 if(colortype == PNG_COLOR_TYPE_GRAY ||
155 colortype == PNG_COLOR_TYPE_GRAY_ALPHA)
157 if(colortype == PNG_COLOR_TYPE_GRAY)
159 pixelFormat = Pixel::L8;
160 if(png_get_valid(png, info, PNG_INFO_tRNS))
162 colortype = PNG_COLOR_TYPE_GRAY_ALPHA;
163 /* expand transparency entry -> alpha channel if present */
164 png_set_tRNS_to_alpha(png);
165 pixelFormat = Pixel::LA88;
170 pixelFormat = Pixel::LA88;
175 /* expand gray (w/reduced bits) -> 8-bit RGB if necessary */
176 png_set_expand_gray_1_2_4_to_8(png);
177 /* pack all pixels to byte boundaries */
178 png_set_packing(png);
182 else if(colortype == PNG_COLOR_TYPE_RGB)
188 pixelFormat = Pixel::RGB888;
192 case 5: /// @todo is this correct for RGB16 5-6-5 ?
194 pixelFormat = Pixel::RGB565;
204 else if(colortype == PNG_COLOR_TYPE_RGBA)
210 pixelFormat = Pixel::RGBA8888;
220 else if(colortype == PNG_COLOR_TYPE_PALETTE)
226 pixelFormat = Pixel::LA88;
235 /* Expand paletted or RGB images with transparency to full alpha channels
236 * so the data will be available as RGBA quartets. PNG_INFO_tRNS = 0x10
238 if(png_get_valid(png, info, PNG_INFO_tRNS) == 0x10)
240 pixelFormat = Pixel::RGBA8888;
245 pixelFormat = Pixel::RGB888;
246 png_set_packing(png);
247 png_set_packswap(png);
248 png_set_palette_to_rgb(png);
262 DALI_LOG_WARNING("Unsupported png format\n");
267 bpp = Pixel::GetBytesPerPixel(pixelFormat);
269 png_read_update_info(png, info);
271 if(setjmp(png_jmpbuf(png)))
273 DALI_LOG_WARNING("error during png_read_image\n");
277 unsigned int rowBytes = png_get_rowbytes(png, info);
279 unsigned int bufferWidth = GetTextureDimension(width);
280 unsigned int bufferHeight = GetTextureDimension(height);
281 unsigned int stride = bufferWidth * bpp;
283 // not sure if this ever happens
284 if(rowBytes > stride)
286 stride = GetTextureDimension(rowBytes);
288 bpp = stride / bufferWidth;
292 pixelFormat = Pixel::RGB888;
295 pixelFormat = Pixel::RGBA8888;
302 // decode the whole image into bitmap buffer
303 auto pixels = (bitmap = Dali::Devel::PixelBuffer::New(bufferWidth, bufferHeight, pixelFormat)).GetBuffer();
305 DALI_ASSERT_DEBUG(pixels);
306 rows = reinterpret_cast<png_bytep*>(malloc(sizeof(png_bytep) * height));
309 DALI_LOG_ERROR("malloc is failed\n");
313 for(y = 0; y < height; y++)
315 rows[y] = pixels + y * stride;
319 png_read_image(png, rows);
326 // simple class to enforce clean-up of PNG structures
329 AutoPngWrite(png_structp& _png, png_infop& _info)
339 png_destroy_write_struct(&png, &info);
345 }; // struct AutoPngWrite;
349 // Custom libpng write callbacks that buffer to a vector instead of a file:
352 * extern "C" linkage is used because this is a callback that we pass to a C
353 * library which is part of the underlying platform and so potentially compiled
354 * as C rather than C++.
355 * @see http://stackoverflow.com/a/2594222
357 extern "C" void WriteData(png_structp png_ptr, png_bytep data, png_size_t length)
359 DALI_ASSERT_DEBUG(png_ptr && data);
360 if(!png_ptr || !data)
364 // Make sure we don't try to propagate a C++ exception up the call stack of a pure C library:
367 // Recover our buffer for writing into:
368 Vector<unsigned char>* const encoded_img = static_cast<Vector<unsigned char>*>(png_get_io_ptr(png_ptr));
371 const Vector<unsigned char>::SizeType bufferSize = encoded_img->Count();
372 encoded_img->Resize(bufferSize + length); //< Can throw OOM.
373 unsigned char* const bufferBack = encoded_img->Begin() + bufferSize;
374 memcpy(bufferBack, data, length);
378 DALI_LOG_ERROR("PNG buffer for write to memory was passed from libpng as null.\n");
383 DALI_LOG_ERROR("C++ Exception caught\n");
387 /** Override the flush with a NOP to prevent libpng trying cstdlib file io. */
388 extern "C" void FlushData(png_structp png_ptr)
391 Debug::LogMessage(Debug::DebugInfo, "PNG Flush");
392 #endif // DEBUG_ENABLED
397 * Potential improvements:
398 * 1. Detect <= 256 colours and write in palette mode.
399 * 2. Detect grayscale (will early-out quickly for colour images).
400 * 3. Store colour space / gamma correction info related to the device screen?
401 * http://www.libpng.org/pub/png/book/chapter10.html
402 * 4. Refactor with callers to write straight through to disk and save keeping a big buffer around.
403 * 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)>.
404 * 6. Set the modification time with png_set_tIME(png_ptr, info_ptr, mod_time);
405 * 7. If caller asks for no compression, bypass libpng and blat raw data to
406 * disk, topped and tailed with header/tail blocks.
408 bool EncodeToPng(const unsigned char* const pixelBuffer, Vector<unsigned char>& encodedPixels, std::size_t width, std::size_t height, Pixel::Format pixelFormat)
410 // Translate pixel format enum:
411 int pngPixelFormat = -1;
412 unsigned pixelBytes = 0;
413 bool rgbaOrder = true;
415 // Account for RGB versus BGR and presence of alpha in input pixels:
420 pngPixelFormat = PNG_COLOR_TYPE_RGB;
424 case Pixel::BGRA8888:
427 ///! No break: fall through:
429 case Pixel::RGBA8888:
431 pngPixelFormat = PNG_COLOR_TYPE_RGB_ALPHA;
437 DALI_LOG_ERROR("Unsupported pixel format for encoding to PNG.\n");
442 const int interlace = PNG_INTERLACE_NONE;
444 png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
449 /* Allocate/initialize the image information data. REQUIRED */
450 png_infop info_ptr = png_create_info_struct(png_ptr);
453 png_destroy_write_struct(&png_ptr, NULL);
457 /* Set error handling. REQUIRED if you aren't supplying your own
458 * error handling functions in the png_create_write_struct() call.
460 if(setjmp(png_jmpbuf(png_ptr)))
462 png_destroy_write_struct(&png_ptr, &info_ptr);
466 // Since we are going to write to memory instead of a file, lets provide
467 // libpng with a custom write function and ask it to pass back our
468 // Vector buffer each time it calls back to flush data to "file":
469 png_set_write_fn(png_ptr, &encodedPixels, WriteData, FlushData);
471 // png_set_compression_level( png_ptr, Z_BEST_COMPRESSION);
472 png_set_compression_level(png_ptr, Z_BEST_SPEED);
473 // png_set_compression_level( png_ptr, Z_NO_COMPRESSION); //! We could just generate png directly without libpng in this case.
475 // Explicitly limit the number of filters used per scanline to speed us up:
476 // png_set_filter(png_ptr, 0, PNG_FILTER_NONE); ///!ToDo: Try this once baseline profile is in place.
480 // PNG_FILTER_PAETH |
482 // Play with Zlib parameters in optimisation phase:
483 // png_set_compression_mem_level(png_ptr, 8);
484 // png_set_compression_strategy(png_ptr,
485 // Z_DEFAULT_STRATEGY);
486 // png_set_compression_window_bits(png_ptr, 15);
487 // png_set_compression_method(png_ptr, 8);
488 // png_set_compression_buffer_size(png_ptr, 8192)
490 // Let lib_png know if the pixel bytes are in BGR(A) order:
493 png_set_bgr(png_ptr);
496 // Set the image information:
497 png_set_IHDR(png_ptr, info_ptr, width, height, 8, pngPixelFormat, interlace, 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