From 09191516c07c7237634f2a22f35a98a218a86ffe Mon Sep 17 00:00:00 2001 From: Egor Yusov Date: Tue, 2 Apr 2019 07:40:13 -0700 Subject: Implemented encoding image as jpeg --- TextureLoader/src/Image.cpp | 131 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 129 insertions(+), 2 deletions(-) (limited to 'TextureLoader/src/Image.cpp') diff --git a/TextureLoader/src/Image.cpp b/TextureLoader/src/Image.cpp index cbbb986..59dc78d 100644 --- a/TextureLoader/src/Image.cpp +++ b/TextureLoader/src/Image.cpp @@ -462,6 +462,103 @@ namespace Diligent png_write_png(Png.strct, Png.info, PNG_TRANSFORM_IDENTITY, NULL); } + static void WriteJPEG(JSAMPLE* pRGBData, Uint32 Width, Uint32 Height, int quality, IDataBlob* pEncodedData) + { + /* 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". + */ + 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. + */ + 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. + */ + auto 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] = { &pRGBData[cinfo.next_scanline * row_stride] }; + jpeg_write_scanlines(&cinfo, row_pointer, 1); + } + + /* Step 6: Finish compression */ + jpeg_finish_compress(&cinfo); + + pEncodedData->Resize(mem_size); + memcpy(pEncodedData->GetDataPtr(), 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); + } void Image::Encode(Uint32 Width, Uint32 Height, @@ -469,13 +566,43 @@ namespace Diligent const void* pData, Uint32 Stride, EImageFileFormat FileFormat, - float JpegQuality, + int JpegQuality, IDataBlob** ppEncodedData) { RefCntAutoPtr pEncodedData(MakeNewRCObj()(0)); if (FileFormat == EImageFileFormat::jpeg) { - + if (TexFormat == TEX_FORMAT_RGBA8_UNORM || + TexFormat == TEX_FORMAT_RGBA8_UNORM_SRGB || + TexFormat == TEX_FORMAT_BGRA8_UNORM || + TexFormat == TEX_FORMAT_BGRA8_UNORM_SRGB) + { + const auto* RGBAData = reinterpret_cast(pData); + std::vector RGBData(Width * Height * 3); + int r_offset = 0; + int g_offset = 1; + int b_offset = 2; + if (TexFormat == TEX_FORMAT_BGRA8_UNORM || + TexFormat == TEX_FORMAT_BGRA8_UNORM_SRGB) + { + r_offset = 2; + b_offset = 0; + } + for(Uint32 j=0; j < Height; ++j) + { + for(Uint32 i=0; i < Width; ++i) + { + RGBData[j * Width * 3 + i*3 + 0] = RGBAData[j * Stride + i*4 + r_offset]; + RGBData[j * Width * 3 + i*3 + 1] = RGBAData[j * Stride + i*4 + g_offset]; + RGBData[j * Width * 3 + i*3 + 2] = RGBAData[j * Stride + i*4 + b_offset]; + } + } + WriteJPEG(RGBData.data(), Width, Height, JpegQuality, pEncodedData); + } + else + { + UNSUPPORTED("This texture format is not currently supported"); + } } else if (FileFormat == EImageFileFormat::png) { -- cgit v1.2.3