C++通过jpeglib进行jpeg编码
C++通过jpeglib进行jpeg编码，输入格式为rgb、yuv422、yuv444
#include <stdio.h> extern "C"{ #include "../../src/jpeg_8c/jpeglib.h" } /** brief jpeg编码，输入格式为uyvy */ void write_YUV_JPEG_file (char * filename, unsigned char* yuvData, int quality, int image_width,int image_height) { struct jpeg_compress_struct cinfo; struct jpeg_error_mgr jerr; FILE * outfile; /* target file */ //JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */ //int row_stride; /* physical row width in image buffer */ JSAMPIMAGE buffer; int band,i,buf_width[3],buf_height[3]; cinfo.err = jpeg_std_error(&jerr); jpeg_create_compress(&cinfo); if ((outfile = fopen(filename, "wb")) == NULL) { fprintf(stderr, "can't open %sn", filename); exit(1); } jpeg_stdio_dest(&cinfo, outfile); cinfo.image_width = image_width; /* image width and height, in pixels */ cinfo.image_height = image_height; cinfo.input_components = 3; /* # of color components per pixel */ cinfo.in_color_space = JCS_YCbCr; /* colorspace of input image */ jpeg_set_defaults(&cinfo); jpeg_set_quality(&cinfo, quality, TRUE ); ////////////////////////////// cinfo.raw_data_in = TRUE; cinfo.jpeg_color_space = JCS_YCbCr; cinfo.comp_info[0].h_samp_factor = 2; cinfo.comp_info[0].v_samp_factor = 1; ///////////////////////// jpeg_start_compress(&cinfo, TRUE); buffer = (JSAMPIMAGE) (*cinfo.mem->alloc_small) ((j_common_ptr) &cinfo, JPOOL_IMAGE, 3 * sizeof(JSAMPARRAY)); for(band=0; band<3; band++) { buf_width[band] = cinfo.comp_info[band].width_in_blocks * DCTSIZE; buf_height[band] = cinfo.comp_info[band].v_samp_factor * DCTSIZE; buffer[band] = (*cinfo.mem->alloc_sarray) ((j_common_ptr) &cinfo, JPOOL_IMAGE, buf_width[band], buf_height[band]); } unsigned char *rawData[3]; rawData[0]=yuvData; rawData[1]=yuvData+image_width*image_height; rawData[2]=yuvData+image_width*image_height*3/2; int max_line = cinfo.max_v_samp_factor*DCTSIZE; for(int counter=0; cinfo.next_scanline < cinfo.image_height; counter++) { //buffer image copy. for(band=0; band<3; band++) { int mem_size = buf_width[band]; unsigned char *pDst = (unsigned char *) buffer[band][0]; unsigned char *pSrc = (unsigned char *) (rawData[band] + //yuv.data[band]分别表示YUV起始地址 counter*buf_height[band] * buf_width[band]); for(i=0; i<buf_height[band]; i++) { memcpy(pDst, pSrc, mem_size); pSrc += buf_width[band]; pDst += buf_width[band]; } } jpeg_write_raw_data(&cinfo, buffer, max_line); } jpeg_finish_compress(&cinfo); fclose(outfile); jpeg_destroy_compress(&cinfo); } /** brief jpeg编码，输入格式为rgb */ void write_RGB_JPEG_file(char * filename, unsigned char *rgb,int image_width, int image_height, int quality /*= 90*/) { JSAMPLE * image_buffer = (JSAMPLE*)rgb; /* 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; /* More stuff */ FILE * outfile; /* target file */ JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */ int row_stride; /* physical row width in image buffer */ /* 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 (eg, a file) */ /* Note: steps 2 and 3 can be done in either order. */ /* Here we use the library-supplied code to send compressed data to a * stdio stream. You can also write your own code to do something else. * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that * requires it in order to write binary files. */ if ((outfile = fopen(filename, "wb")) == NULL) { fprintf(stderr, "can't open %sn", filename); exit(1); } jpeg_stdio_dest(&cinfo, outfile); /* 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 = image_width; /* image width and height, in pixels */ cinfo.image_height = image_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. */ row_stride = image_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. */ row_pointer[0] = & image_buffer[cinfo.next_scanline * row_stride]; (void) jpeg_write_scanlines(&cinfo, row_pointer, 1); } /* Step 6: Finish compression */ jpeg_finish_compress(&cinfo); /* After finish_compress, we can close the output file. */ fclose(outfile); /* Step 7: release JPEG compression object */ /* This is an important step since it will release a good deal of memory. */ jpeg_destroy_compress(&cinfo); /* And we're done! */ } /** brief jpeg编码，输入格式为yuv444 */ void write_YUV444_JPEG_file(char * filename, unsigned char *yuv444,int image_width, int image_height, int quality /*= 90*/) { JSAMPLE * image_buffer = (JSAMPLE*)yuv444; /* 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; /* More stuff */ FILE * outfile; /* target file */ JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */ int row_stride; /* physical row width in image buffer */ /* 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 (eg, a file) */ /* Note: steps 2 and 3 can be done in either order. */ /* Here we use the library-supplied code to send compressed data to a * stdio stream. You can also write your own code to do something else. * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that * requires it in order to write binary files. */ if ((outfile = fopen(filename, "wb")) == NULL) { fprintf(stderr, "can't open %sn", filename); exit(1); } jpeg_stdio_dest(&cinfo, outfile); /* 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 = image_width; /* image width and height, in pixels */ cinfo.image_height = image_height; cinfo.input_components = 3; /* # of color components per pixel */ cinfo.in_color_space = JCS_YCbCr; /* 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. */ row_stride = image_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. */ row_pointer[0] = & image_buffer[cinfo.next_scanline * row_stride]; (void) jpeg_write_scanlines(&cinfo, row_pointer, 1); } /* Step 6: Finish compression */ jpeg_finish_compress(&cinfo); /* After finish_compress, we can close the output file. */ fclose(outfile); /* Step 7: release JPEG compression object */ /* This is an important step since it will release a good deal of memory. */ jpeg_destroy_compress(&cinfo); /* And we're done! */ }