ref: 02c6058f5d529e41afb0208c69f0cbf694b02b18
dir: /sys/src/cmd/jpg/readv210.c/
/* * readV210.c - read single uncompressed Quicktime YUV image. * http://developer.apple.com/quicktime/icefloe/dispatch019.html#v210 * Steve Simon, 2009 */ #include <u.h> #include <libc.h> #include <bio.h> #include <draw.h> #include <ctype.h> #include "imagefile.h" enum { Pixels = 720, R601pal = 576, R601ntsc = 486, Shift = 13 }; static int looksize(char *file, vlong size, int *pixels, int *lines, int *chunk) { Biobuf *bp; uvlong l, p, c; char *s, *a[12]; /* * This may not always work, there could be an alias between file * sizes of different standards stored in 8bits and 10 bits. */ if((bp = Bopen(file, OREAD)) == nil) return -1; while((s = Brdstr(bp, '\n', 1)) != nil){ if(tokenize(s, a, nelem(a)) < 3) continue; if(a[0][0] == '#') continue; p = atoll(a[3]); l = atoll(a[5]); l += atoll(a[7]); c = 128 * ceil(p/48); if(l*c == size){ *pixels = p; *lines = l; *chunk = c; break; } } Bterm(bp); if(s == nil) return -1; return 0; } static int clip(int x) { x >>= Shift + 2; /* +2 as we assume all input images are 10 bit */ if(x > 255) return 0xff; if(x <= 0) return 0; return x; } Rawimage** BreadV210(Biobuf *bp, int colourspace) { Dir *d; uvlong sz; Rawimage *a, **array; ushort *mux, *end, *frm, *wr; uchar *buf, *r, *g, *b; uint i, t; int y1, y2, cb, cr, c, l, rd; int chunk, lines, pixels; int F1, F2, F3, F4; buf = nil; if(colourspace != CYCbCr){ werrstr("BreadV210: unknown colour space %d", colourspace); return nil; } if((d = dirfstat(Bfildes(bp))) != nil){ sz = d->length; free(d); } else { fprint(2, "cannot stat input, assuming pixelsx576x10bit\n"); sz = Pixels * R601pal * 2L + (pixels * R601pal / 2L); } if(looksize("/lib/video.specs", sz, &pixels, &lines, &chunk) == -1){ werrstr("file spec not in /lib/video.specs\n"); 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; a->nchans = 3; a->chandesc = CRGB; a->chanlen = pixels * lines; a->r = Rect(0, 0, pixels, lines); if((frm = malloc(pixels*2*lines*sizeof(ushort))) == nil) goto Error; for(c = 0; c < 3; c++) if((a->chans[c] = malloc(pixels*lines)) == nil) goto Error; if((buf = malloc(chunk)) == nil) goto Error; for(l = 0; l < lines; l++){ if(Bread(bp, buf, chunk) == -1) goto Error; rd = 0; wr = &frm[l*pixels*2]; end = &frm[(l+1)*pixels*2]; while(wr < end){ t = 0; for(i = 0; i < 4; i++) t += buf[rd+i] << 8*i; *wr++ = t & 0x3ff; *wr++ = t>>10 & 0x3ff; *wr++ = t>>20 & 0x3ff; rd += 4; } } mux = frm; end = frm + pixels * lines * 2; r = a->chans[0]; g = a->chans[1]; b = a->chans[2]; if(pixels == Pixels && lines != R601pal){ // 625 F1 = floor(1.402 * (1 << Shift)); F2 = floor(0.34414 * (1 << Shift)); F3 = floor(0.71414 * (1 << Shift)); F4 = floor(1.772 * (1 << Shift)); } else{ // 525 and HD F1 = floor(1.5748 * (1 << Shift)); F2 = floor(0.1874 * (1 << Shift)); F3 = floor(0.4681 * (1 << Shift)); F4 = floor(1.8560 * (1 << Shift)); } /* * Fixme: fixed colourspace conversion at present */ while(mux < end){ cb = *mux++ - 512; y1 = (int)*mux++ << Shift; cr = *mux++ - 512; y2 = (int)*mux++ << Shift; *r++ = clip(y1 + F1*cr); *g++ = clip(y1 - F2*cb - F3*cr); *b++ = clip((y1 + F4*cb)); *r++ = clip(y2 + F1*cr); *g++ = clip(y2 - F2*cb - F3*cr); *b++ = clip((y2 + F4*cb)); } free(frm); free(buf); return array; Error: for(c = 0; c < 3; c++) free(a->chans[c]); free(a->cmap); free(array[0]); free(array); free(frm); free(buf); return nil; } Rawimage** readV210(int fd, int colorspace) { Rawimage * *a; Biobuf b; if(Binit(&b, fd, OREAD) < 0) return nil; a = BreadV210(&b, colorspace); Bterm(&b); return a; }