diff options
Diffstat (limited to 'converter/ppm/yuvtoppm.c')
-rw-r--r-- | converter/ppm/yuvtoppm.c | 255 |
1 files changed, 180 insertions, 75 deletions
diff --git a/converter/ppm/yuvtoppm.c b/converter/ppm/yuvtoppm.c index 2b44c65f..151ff9f9 100644 --- a/converter/ppm/yuvtoppm.c +++ b/converter/ppm/yuvtoppm.c @@ -20,96 +20,201 @@ ** implied warranty. */ -#include "ppm.h" +#include "pm_c_util.h" #include "mallocvar.h" +#include "shhopt.h" +#include "ppm.h" -/* x must be signed for the following to work correctly */ -#define limit(x) ((((x)>0xffffff)?0xff0000:(((x)<=0xffff)?0:(x)&0xff0000))>>16) -int -main(argc, argv) - char **argv; -{ - FILE *ifp; - pixel *pixrow; - int argn, rows, cols, row; - const char * const usage = "<width> <height> [yuvfile]"; - struct yuv { - /* This is an element of a YUV file. It describes two - side-by-side pixels. - */ - unsigned char u; - unsigned char y1; - unsigned char v; - unsigned char y2; - } *yuvbuf; - - ppm_init(&argc, argv); - - argn = 1; - - if (argn + 2 > argc) - pm_usage(usage); - - cols = atoi(argv[argn++]); - rows = atoi(argv[argn++]); - if (cols <= 0 || rows <= 0) - pm_usage(usage); - - if (argn < argc) { - ifp = pm_openr(argv[argn]); - ++argn; - } else - ifp = stdin; - - if (argn != argc) - pm_usage(usage); - - if (cols % 2 != 0) { - pm_error("Number of columns (%d) is odd. A YUV image must have an " - "even number of columns.", cols); + +struct CmdlineInfo { + /* All the information the user supplied in the command line, + in a form easy for the program to use. + */ + unsigned int cols; + unsigned int rows; + const char * inputFileName; /* Name of input file */ +}; + + + +static void +parseCommandLine(int argc, const char ** argv, + struct CmdlineInfo * const cmdlineP) { + + optEntry * option_def; + /* Instructions to OptParseOptions3 on how to parse our options */ + optStruct3 opt; + + MALLOCARRAY_NOFAIL(option_def, 100); + + OPTENTINIT; + + opt.opt_table = option_def; + opt.short_allowed = FALSE; /* We have no short (old-fashioned) options */ + opt.allowNegNum = FALSE; /* We have no parms that are negative numbers */ + + pm_optParseOptions3(&argc, (char **)argv, opt, sizeof(opt), 0); + /* Uses and sets argc, argv, and some of *cmdlineP and others. */ + + if (argc-1 < 2) + pm_error("You need at least two arguments: width and height in " + "pixels. You specified %u", argc-1); + else { + int const widthArg = atoi(argv[1]); + int const heightArg = atoi(argv[2]); + + if (widthArg < 0) + pm_error("Negative number for width: %d", widthArg); + if (heightArg < 0) + pm_error("Negative number for height: %d", heightArg); + + cmdlineP->cols = widthArg; + cmdlineP->rows = heightArg; + + if (cmdlineP->cols % 2 != 0) + pm_error("Number of columns (%u) is odd. " + "A YUV image must have an " + "even number of columns.", cmdlineP->cols); + + if (argc-1 < 3) + cmdlineP->inputFileName = "-"; + else { + cmdlineP->inputFileName = argv[3]; + + if (argc-1 > 3) + pm_error("Too many arguments: %u. " + "The only possible arguments are " + "width, height, and input file name", argc-1); + } } +} - ppm_writeppminit(stdout, cols, rows, (pixval) 255, 0); - pixrow = ppm_allocrow(cols); - MALLOCARRAY(yuvbuf, (cols+1)/2); - if (yuvbuf == NULL) - pm_error("Unable to allocate YUV buffer for %d columns.", cols); - for (row = 0; row < rows; ++row) { - int col; - fread(yuvbuf, cols * 2, 1, ifp); +static int +limit(int const x) { - for (col = 0; col < cols; col += 2) { - /* Produce two pixels in pixrow[] */ - int y1, u, v, y2, r, g, b; + if (x > 0xffffff) + return 0xff; + else if (x <= 0xffff) + return 0; + else + return ((x >> 16) & 0xff); +} + + + +static int +nonneg(int const x) { +/*---------------------------------------------------------------------------- + Raise 'x' to 0 if negative +-----------------------------------------------------------------------------*/ + return x < 0 ? 0 : x; +} + + + +struct Yuv { +/*---------------------------------------------------------------------------- + This is an element of a YUV file. It describes two side-by-side pixels. + + This is the actual layout of the data in the file (4 bytes). +-----------------------------------------------------------------------------*/ + unsigned char u; + unsigned char y1; + unsigned char v; + unsigned char y2; +}; - u = yuvbuf[col/2].u-128; - y1 = yuvbuf[col/2].y1 - 16; - if (y1 < 0) y1 = 0; - v = yuvbuf[col/2].v - 128; +static void +readYuv(FILE * const ifP, + struct Yuv * const yuvP) { - y2 = yuvbuf[col/2].y2 - 16; - if (y2 < 0) y2 = 0; + size_t readCt; - r = 104635 * v; - g = -25690 * u + -53294 * v; - b = 132278 * u; + readCt = fread(yuvP, sizeof(*yuvP), 1, ifP); - y1*=76310; y2*=76310; + if (readCt != 1) { + if (feof(ifP)) + pm_error("Premature end of input."); + else + pm_error("Error reading input."); + } +} + + + +static void +yuvtoppm(FILE * const ifP, + unsigned int const cols, + unsigned int const rows, + FILE * const ofP) { + + pixval const maxval = 255; + + pixel * pixrow; + unsigned int row; + + ppm_writeppminit(ofP, cols, rows, maxval, 0); + + pixrow = ppm_allocrow(cols); + + for (row = 0; row < rows; ++row) { + unsigned int col; + for (col = 0; col < cols; col += 2) { + /* Produce two pixels in pixrow[] */ + struct Yuv yuv; + int y1, u, v, y2, r, g, b; + + readYuv(ifP, &yuv); + + u = yuv.u - 128; + y1 = nonneg (yuv.y1 - 16); + v = yuv.v - 128; + y2 = nonneg (yuv.y2 - 16); + + r = 104635 * v; + g = -25690 * u + -53294 * v; + b = 132278 * u; + + y1 *= 76310; + y2 *= 76310; + + PPM_ASSIGN(pixrow[col], + limit(r + y1), limit(g + y1), limit(b + y1)); + PPM_ASSIGN(pixrow[col + 1], + limit(r + y2), limit(g + y2), limit(b + y2)); + } + ppm_writeppmrow(ofP, pixrow, cols, maxval, 0); + } - PPM_ASSIGN(pixrow[col], limit(r+y1), limit(g+y1), limit(b+y1)); - PPM_ASSIGN(pixrow[col+1], limit(r+y2), limit(g+y2), limit(b+y2)); - } - ppm_writeppmrow(stdout, pixrow, cols, (pixval) 255, 0); - } - free(yuvbuf); ppm_freerow(pixrow); - pm_close(ifp); - pm_close(stdout); - exit(0); + if (fgetc(ifP) != EOF) + pm_message("Extraneous data at end of image."); +} + + + +int +main (int argc, const char ** argv) { + + FILE * ifP; + struct CmdlineInfo cmdline; + + pm_proginit(&argc, argv); + + parseCommandLine(argc, argv, &cmdline); + + ifP = pm_openr(cmdline.inputFileName); + + yuvtoppm(ifP, cmdline.cols, cmdline.rows, stdout); + + pm_close(ifP); + pm_close(stdout); + + return 0; } |