| // SPDX-License-Identifier: Apache-2.0 | |
| // ---------------------------------------------------------------------------- | |
| // Copyright 2021-2024 Arm Limited | |
| // | |
| // Licensed under the Apache License, Version 2.0 (the "License"); you may not | |
| // use this file except in compliance with the License. You may obtain a copy | |
| // of the License at: | |
| // | |
| // http://www.apache.org/licenses/LICENSE-2.0 | |
| // | |
| // Unless required by applicable law or agreed to in writing, software | |
| // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT | |
| // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the | |
| // License for the specific language governing permissions and limitations | |
| // under the License. | |
| // ---------------------------------------------------------------------------- | |
| // This is a minimal example of using the astcenc library. | |
| // | |
| // This sample shows how to include the astcenc library in your CMake project | |
| // as an external dependency, and how to compress and decompress images using | |
| // the C library API. | |
| // | |
| // For sake of clarity the command line exposed by the sample is minimalistic, | |
| // and the compression uses a fixed set of options, but the code is commented | |
| // to indicate where extension would be possible. Errors handling points are | |
| // detected and logged, but resources are not cleaned up on error paths to keep | |
| // the sample control path simple, so resources will leak on error. | |
| int main(int argc, char **argv) | |
| { | |
| // Parse command line | |
| if (argc != 3) | |
| { | |
| printf("Usage:\n" | |
| " %s <source> <dest>\n\n" | |
| " <source> : Uncompressed LDR source image.\n" | |
| " <dest> : Uncompressed LDR destination image (png).\n" | |
| , argv[0]); | |
| return 1; | |
| } | |
| // ------------------------------------------------------------------------ | |
| // For the purposes of this sample we hard-code the compressor settings | |
| static const unsigned int thread_count = 1; | |
| static const unsigned int block_x = 6; | |
| static const unsigned int block_y = 6; | |
| static const unsigned int block_z = 1; | |
| static const astcenc_profile profile = ASTCENC_PRF_LDR; | |
| static const float quality = ASTCENC_PRE_MEDIUM; | |
| static const astcenc_swizzle swizzle { | |
| ASTCENC_SWZ_R, ASTCENC_SWZ_G, ASTCENC_SWZ_B, ASTCENC_SWZ_A | |
| }; | |
| // ------------------------------------------------------------------------ | |
| // Load input image, forcing 4 components | |
| int image_x, image_y, image_c; | |
| uint8_t *image_data = (uint8_t*)stbi_load(argv[1], &image_x, &image_y, &image_c, 4); | |
| if (!image_data) | |
| { | |
| printf("Failed to load image \"%s\"\n", argv[1]); | |
| return 1; | |
| } | |
| // Compute the number of ASTC blocks in each dimension | |
| unsigned int block_count_x = (image_x + block_x - 1) / block_x; | |
| unsigned int block_count_y = (image_y + block_y - 1) / block_y; | |
| // ------------------------------------------------------------------------ | |
| // Initialize the default configuration for the block size and quality | |
| astcenc_config config; | |
| astcenc_error status; | |
| status = astcenc_config_init(profile, block_x, block_y, block_z, quality, 0, &config); | |
| if (status != ASTCENC_SUCCESS) | |
| { | |
| printf("ERROR: Codec config init failed: %s\n", astcenc_get_error_string(status)); | |
| return 1; | |
| } | |
| // ... power users can customize any config settings after calling | |
| // config_init() and before calling context alloc(). | |
| // ------------------------------------------------------------------------ | |
| // Create a context based on the configuration | |
| astcenc_context* context; | |
| status = astcenc_context_alloc(&config, thread_count, &context); | |
| if (status != ASTCENC_SUCCESS) | |
| { | |
| printf("ERROR: Codec context alloc failed: %s\n", astcenc_get_error_string(status)); | |
| return 1; | |
| } | |
| // ------------------------------------------------------------------------ | |
| // Compress the image | |
| astcenc_image image; | |
| image.dim_x = image_x; | |
| image.dim_y = image_y; | |
| image.dim_z = 1; | |
| image.data_type = ASTCENC_TYPE_U8; | |
| uint8_t* slices = image_data; | |
| image.data = reinterpret_cast<void**>(&slices); | |
| // Space needed for 16 bytes of output per compressed block | |
| size_t comp_len = block_count_x * block_count_y * 16; | |
| uint8_t* comp_data = new uint8_t[comp_len]; | |
| status = astcenc_compress_image(context, &image, &swizzle, comp_data, comp_len, 0); | |
| if (status != ASTCENC_SUCCESS) | |
| { | |
| printf("ERROR: Codec compress failed: %s\n", astcenc_get_error_string(status)); | |
| return 1; | |
| } | |
| // ... the comp_data array contains the raw compressed data you would pass | |
| // to the graphics API, or pack into a wrapper format such as a KTX file. | |
| // If using multithreaded compression to sequentially compress multiple | |
| // images you should reuse the same context, calling the function | |
| // astcenc_compress_reset() between each image in the series. | |
| // ------------------------------------------------------------------------ | |
| // Decompress the image | |
| // Note we just reuse the image structure to store the output here ... | |
| status = astcenc_decompress_image(context, comp_data, comp_len, &image, &swizzle, 0); | |
| if (status != ASTCENC_SUCCESS) | |
| { | |
| printf("ERROR: Codec decompress failed: %s\n", astcenc_get_error_string(status)); | |
| return 1; | |
| } | |
| // If using multithreaded decompression to sequentially decompress multiple | |
| // images you should reuse the same context, calling the function | |
| // astcenc_decompress_reset() between each image in the series. | |
| // ------------------------------------------------------------------------ | |
| // Store the result back to disk | |
| stbi_write_png(argv[2], image_x, image_y, 4, image_data, 4 * image_x); | |
| // ------------------------------------------------------------------------ | |
| // Cleanup library resources | |
| stbi_image_free(image_data); | |
| astcenc_context_free(context); | |
| delete[] comp_data; | |
| return 0; | |
| } | |