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Diffstat (limited to 'TextureLoader/src/JPEGCodec.c')
| -rw-r--r-- | TextureLoader/src/JPEGCodec.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/TextureLoader/src/JPEGCodec.c b/TextureLoader/src/JPEGCodec.c new file mode 100644 index 0000000..d5398a5 --- /dev/null +++ b/TextureLoader/src/JPEGCodec.c @@ -0,0 +1,278 @@ +/* + * Copyright 2019-2020 Diligent Graphics LLC + * Copyright 2015-2019 Egor Yusov + * + * 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. + * + * In no event and under no legal theory, whether in tort (including negligence), + * contract, or otherwise, unless required by applicable law (such as deliberate + * and grossly negligent acts) or agreed to in writing, shall any Contributor be + * liable for any damages, including any direct, indirect, special, incidental, + * or consequential damages of any character arising as a result of this License or + * out of the use or inability to use the software (including but not limited to damages + * for loss of goodwill, work stoppage, computer failure or malfunction, or any and + * all other commercial damages or losses), even if such Contributor has been advised + * of the possibility of such damages. + */ + +#include <stdlib.h> +#include <string.h> +#include <setjmp.h> +#include <stdio.h> + +#include "jpeglib.h" + +#include "JPEGCodec.h" + + +struct my_jpeg_error_mgr +{ + struct jpeg_error_mgr pub; + char padding[8]; + jmp_buf setjmp_buffer; // for return to caller +}; +typedef struct my_jpeg_error_mgr my_jpeg_error_mgr; + +// Here's the routine that will replace the standard error_exit method: +METHODDEF(void) +my_error_exit(j_common_ptr cinfo) +{ + // cinfo->err really points to a my_jpeg_error_mgr struct, so coerce pointer + my_jpeg_error_mgr* myerr = (my_jpeg_error_mgr*)cinfo->err; + + /* Always display the message. */ + /* We could postpone this until after returning, if we chose. */ + (*cinfo->err->output_message)(cinfo); + + // Return control to the setjmp point + longjmp(myerr->setjmp_buffer, 1); +} + +DECODE_JPEG_RESULT Diligent_DecodeJpeg(IDataBlob* pSrcJpegBits, + IDataBlob* pDstPixels, + ImageDesc* pDstImgDesc) +{ + if (!pSrcJpegBits || !pDstPixels || !pDstImgDesc) + return DECODE_JPEG_RESULT_INVALID_ARGUMENTS; + + // https://github.com/LuaDist/libjpeg/blob/master/example.c + + // This struct contains the JPEG decompression parameters and pointers to + // working space (which is allocated as needed by the JPEG library). + struct jpeg_decompress_struct cinfo; + + // We use our private extension JPEG error handler. + // Note that this struct must live as long as the main JPEG parameter + // struct, to avoid dangling-pointer problems. + my_jpeg_error_mgr jerr; + + // Step 1: allocate and initialize JPEG decompression object + + // We set up the normal JPEG error routines, then override error_exit. + cinfo.err = jpeg_std_error(&jerr.pub); + jerr.pub.error_exit = my_error_exit; + // Establish the setjmp return context for my_error_exit to use. + if (setjmp(jerr.setjmp_buffer)) + { + // If we get here, the JPEG code has signaled an error. + // We need to clean up the JPEG object, close the input file, and return. + jpeg_destroy_decompress(&cinfo); + return DECODE_JPEG_RESULT_INITIALIZATION_FAILED; + } + + // Now we can initialize the JPEG decompression object. + jpeg_create_decompress(&cinfo); + + // Step 2: specify data source + unsigned char* pSrcPtr = IDataBlob_GetDataPtr(pSrcJpegBits); + unsigned long SrcSize = (unsigned long)IDataBlob_GetSize(pSrcJpegBits); + jpeg_mem_src(&cinfo, pSrcPtr, SrcSize); + + // Step 3: read file parameters with jpeg_read_header() + jpeg_read_header(&cinfo, TRUE); + // We can ignore the return value from jpeg_read_header since + // (a) suspension is not possible with the stdio data source, and + // (b) we passed TRUE to reject a tables-only JPEG file as an error. + // See libjpeg.txt for more info. + + + // Step 4: set parameters for decompression + + // In this example, we don't need to change any of the defaults set by + // jpeg_read_header(), so we do nothing here. + + + // Step 5: Start decompressor + + jpeg_start_decompress(&cinfo); + // We can ignore the return value since suspension is not possible + // with the stdio data source. + + // We may need to do some setup of our own at this point before reading + // the data. After jpeg_start_decompress() we have the correct scaled + // output image dimensions available, as well as the output colormap + // if we asked for color quantization. + + pDstImgDesc->Width = cinfo.output_width; + pDstImgDesc->Height = cinfo.output_height; + pDstImgDesc->ComponentType = VT_UINT8; + pDstImgDesc->NumComponents = cinfo.output_components; + pDstImgDesc->RowStride = pDstImgDesc->Width * pDstImgDesc->NumComponents; + pDstImgDesc->RowStride = (pDstImgDesc->RowStride + 3u) & ~3u; + + IDataBlob_Resize(pDstPixels, pDstImgDesc->RowStride * pDstImgDesc->Height); + // Step 6: while (scan lines remain to be read) + // jpeg_read_scanlines(...); + + // Here we use the library's state variable cinfo.output_scanline as the + // loop counter, so that we don't have to keep track ourselves. + while (cinfo.output_scanline < cinfo.output_height) + { + // jpeg_read_scanlines expects an array of pointers to scanlines. + // Here the array is only one element long, but you could ask for + // more than one scanline at a time if that's more convenient. + + Uint8* pScanline0 = IDataBlob_GetDataPtr(pDstPixels); + Uint8* pDstScanline = pScanline0 + cinfo.output_scanline * pDstImgDesc->RowStride; + JSAMPROW RowPtrs[1]; + RowPtrs[0] = (JSAMPROW)pDstScanline; + jpeg_read_scanlines(&cinfo, RowPtrs, 1); + } + + // Step 7: Finish decompression + + jpeg_finish_decompress(&cinfo); + // We can ignore the return value since suspension is not possible + // with the stdio data source. + + // Step 8: Release JPEG decompression object + + // This is an important step since it will release a good deal of memory. + jpeg_destroy_decompress(&cinfo); + + // At this point you may want to check to see whether any corrupt-data + // warnings occurred (test whether jerr.pub.num_warnings is nonzero). + + return DECODE_JPEG_RESULT_OK; +} + + + +ENCODE_JPEG_RESULT Diligent_EncodeJpeg(Uint8* pSrcRGBPixels, + Uint32 Width, + Uint32 Height, + int quality, + IDataBlob* pDstJpegBits) +{ + if (!pSrcRGBPixels || !pDstJpegBits || quality < 0 || Width == 0 || Height == 0) + return ENCODE_JPEG_RESULT_INVALID_ARGUMENTS; + + /* This struct contains the JPEG compression parameters and pointers to + * working space (which is allocated as needed by the JPEG library). + * It is possible to have several such structures, representing multiple + * compression/decompression processes, in existence at once. We refer + * to any one struct (and its associated working data) as a "JPEG object". + */ + struct jpeg_compress_struct cinfo; + + /* This struct represents a JPEG error handler. It is declared separately + * because applications often want to supply a specialized error handler + * (see the second half of this file for an example). But here we just + * take the easy way out and use the standard error handler, which will + * print a message on stderr and call exit() if compression fails. + * Note that this struct must live as long as the main JPEG parameter + * struct, to avoid dangling-pointer problems. + */ + struct jpeg_error_mgr jerr; + + /* Step 1: allocate and initialize JPEG compression object */ + + /* We have to set up the error handler first, in case the initialization + * step fails. (Unlikely, but it could happen if you are out of memory.) + * This routine fills in the contents of struct jerr, and returns jerr's + * address which we place into the link field in cinfo. + */ + cinfo.err = jpeg_std_error(&jerr); + /* Now we can initialize the JPEG compression object. */ + jpeg_create_compress(&cinfo); + + /* Step 2: specify data destination (memory) */ + /* Note: steps 2 and 3 can be done in either order. */ + unsigned char* mem = NULL; + unsigned long mem_size = 0; + jpeg_mem_dest(&cinfo, &mem, &mem_size); + + /* Step 3: set parameters for compression */ + + /* First we supply a description of the input image. + * Four fields of the cinfo struct must be filled in: + */ + cinfo.image_width = Width; /* image width and height, in pixels */ + cinfo.image_height = Height; + cinfo.input_components = 3; /* # of color components per pixel */ + cinfo.in_color_space = JCS_RGB; /* colorspace of input image */ + /* Now use the library's routine to set default compression parameters. + * (You must set at least cinfo.in_color_space before calling this, + * since the defaults depend on the source color space.) + */ + jpeg_set_defaults(&cinfo); + /* Now you can set any non-default parameters you wish to. + * Here we just illustrate the use of quality (quantization table) scaling: + */ + jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */); + + /* Step 4: Start compressor */ + + /* TRUE ensures that we will write a complete interchange-JPEG file. + * Pass TRUE unless you are very sure of what you're doing. + */ + jpeg_start_compress(&cinfo, TRUE); + + /* Step 5: while (scan lines remain to be written) */ + /* jpeg_write_scanlines(...); */ + + /* Here we use the library's state variable cinfo.next_scanline as the + * loop counter, so that we don't have to keep track ourselves. + * To keep things simple, we pass one scanline per call; you can pass + * more if you wish, though. + */ + Uint32 row_stride = Width * 3; /* JSAMPLEs per row in image_buffer */ + + while (cinfo.next_scanline < cinfo.image_height) + { + /* jpeg_write_scanlines expects an array of pointers to scanlines. + * Here the array is only one element long, but you could pass + * more than one scanline at a time if that's more convenient. + */ + JSAMPROW row_pointer[1]; + row_pointer[0] = &pSrcRGBPixels[cinfo.next_scanline * row_stride]; + jpeg_write_scanlines(&cinfo, row_pointer, 1); + } + + /* Step 6: Finish compression */ + jpeg_finish_compress(&cinfo); + + IDataBlob_Resize(pDstJpegBits, mem_size); + void* pDstPtr = IDataBlob_GetDataPtr(pDstJpegBits); + memcpy(pDstPtr, mem, mem_size); + + /* After finish_compress, we can free memory buffer. */ + free(mem); + + /* Step 7: release JPEG compression object */ + + /* This is an important step since it will release a good deal of memory. */ + jpeg_destroy_compress(&cinfo); + + return ENCODE_JPEG_RESULT_OK; +} |