/* * Copyright 2019-2021 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 #include #include #include #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; }