diff options
Diffstat (limited to 'src/cmd/jpg/readyuv.c')
| -rw-r--r-- | src/cmd/jpg/readyuv.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/src/cmd/jpg/readyuv.c b/src/cmd/jpg/readyuv.c new file mode 100644 index 00000000..eae2764e --- /dev/null +++ b/src/cmd/jpg/readyuv.c @@ -0,0 +1,190 @@ +/* readyuv.c - read an Abekas A66 style image file. Steve Simon, 2003 */ +#include <u.h> +#include <libc.h> +#include <bio.h> +#include <draw.h> +#include <ctype.h> +#include "imagefile.h" + +/* + * ITU/CCIR Rec601 states: + * + * R = y + 1.402 * Cr + * B = Y + 1.77305 * Cb + * G = Y - 0.72414 * Cr - 0.34414 * Cb + * + * using 8 bit traffic + * Y = 16 + 219 * Y + * Cr = 128 + 224 * Cr + * Cb = 128 + 224 * Cb + * or, if 10bit is used + * Y = 64 + 876 * Y + * Cr = 512 + 896 * Cr + * Cb = 512 + 896 * Cb + */ + +enum { + PAL = 576, NTSC = 486 }; + + +static int lsbtab[] = { 6, 4, 2, 0}; + +static int +clip(int x) +{ + x >>= 18; + + if (x > 255) + return 0xff; + if (x <= 0) + return 0; + return x; +} + + +Rawimage** +Breadyuv(Biobuf *bp, int colourspace) +{ + Dir * d; + Rawimage * a, **array; + char *e, ebuf[128]; + ushort * mux, *end, *frm; + uchar buf[720 * 2], *r, *g, *b; + int y1, y2, cb, cr, sz, c, l, w, base, bits, lines; + + frm = 0; + if (colourspace != CYCbCr) { + errstr(ebuf, sizeof ebuf); /* throw it away */ + werrstr("ReadYUV: unknown colour space %d", colourspace); + return nil; + } + + if ((a = calloc(sizeof(Rawimage), 1)) == nil) + sysfatal("no memory"); + + if ((array = calloc(sizeof(Rawimage * ), 2)) == nil) + sysfatal("no memory"); + array[0] = a; + array[1] = nil; + + if ((d = dirfstat(Bfildes(bp))) != nil) { + sz = d->length; + free(d); + } else { + fprint(2, "cannot stat input, assuming 720x576x10bit\n"); + sz = 720 * PAL * 2L + (720 * PAL / 2L); + } + + switch (sz) { + case 720 * PAL * 2: // 625 x 8bit + bits = 8; + lines = PAL; + break; + case 720 * NTSC * 2: // 525 x 8bit + bits = 8; + lines = NTSC; + break; + case 720 * PAL * 2 + (720 * PAL / 2) : // 625 x 10bit + bits = 10; + lines = PAL; + break; + case 720 * NTSC * 2 + (720 * NTSC / 2) : // 525 x 10bit + bits = 10; + lines = NTSC; + break; + default: + e = "unknown file size"; + goto Error; + } + + // print("bits=%d pixels=%d lines=%d\n", bits, 720, lines); + // + a->nchans = 3; + a->chandesc = CRGB; + a->chanlen = 720 * lines; + a->r = Rect(0, 0, 720, lines); + + e = "no memory"; + if ((frm = malloc(720 * 2 * lines * sizeof(ushort))) == nil) + goto Error; + + for (c = 0; c < 3; c++) + if ((a->chans[c] = malloc(720 * lines)) == nil) + goto Error; + + e = "read file"; + for (l = 0; l < lines; l++) { + if (Bread(bp, buf, 720 * 2) == -1) + goto Error; + + base = l * 720 * 2; + for (w = 0; w < 720 * 2; w++) + frm[base + w] = ((ushort)buf[w]) << 2; + } + + + if (bits == 10) + for (l = 0; l < lines; l++) { + if (Bread(bp, buf, 720 / 2) == -1) + goto Error; + + + base = l * 720 * 2; + for (w = 0; w < 720 * 2; w++) + frm[base + w] |= buf[w / 4] >> lsbtab[w % 4]; + } + + mux = frm; + end = frm + 720 * lines * 2; + r = a->chans[0]; + g = a->chans[1]; + b = a->chans[2]; + + while (mux < end) { + cb = *mux++ - 512; + y1 = (*mux++ - 64) * 76310; + cr = *mux++ - 512; + y2 = (*mux++ - 64) * 76310; + + *r++ = clip((104635 * cr) + y1); + *g++ = clip((-25690 * cb + -53294 * cr) + y1); + *b++ = clip((132278 * cb) + y1); + + *r++ = clip((104635 * cr) + y2); + *g++ = clip((-25690 * cb + -53294 * cr) + y2); + *b++ = clip((132278 * cb) + y2); + } + free(frm); + return array; + +Error: + + errstr(ebuf, sizeof ebuf); + if (ebuf[0] == 0) + strcpy(ebuf, e); + errstr(ebuf, sizeof ebuf); + + for (c = 0; c < 3; c++) + free(a->chans[c]); + free(a->cmap); + free(array[0]); + free(array); + free(frm); + return nil; +} + + +Rawimage** +readyuv(int fd, int colorspace) +{ + Rawimage * *a; + Biobuf b; + + if (Binit(&b, fd, OREAD) < 0) + return nil; + a = Breadyuv(&b, colorspace); + Bterm(&b); + return a; +} + + |