diff options
Diffstat (limited to 'filter/predict.c')
| -rw-r--r-- | filter/predict.c | 238 |
1 files changed, 0 insertions, 238 deletions
diff --git a/filter/predict.c b/filter/predict.c deleted file mode 100644 index d7b594ac..00000000 --- a/filter/predict.c +++ /dev/null @@ -1,238 +0,0 @@ -#include <fitz.h> - -/* TODO: check if this works with 16bpp images */ - -enum { MAXC = 16 }; - -typedef struct fz_predict_s fz_predict; - -struct fz_predict_s -{ - fz_filter super; - - int predictor; - int columns; - int colors; - int bpc; - - int stride; - int bpp; - unsigned char *ref; - - int encode; -}; - -fz_error * -fz_newpredict(fz_filter **fp, fz_obj *params, int encode) -{ - fz_obj *obj; - - FZ_NEWFILTER(fz_predict, p, predict); - - p->encode = encode; - - p->predictor = 1; - p->columns = 1; - p->colors = 1; - p->bpc = 8; - - obj = fz_dictgets(params, "Predictor"); - if (obj) p->predictor = fz_toint(obj); - - obj = fz_dictgets(params, "Columns"); - if (obj) p->columns = fz_toint(obj); - - obj = fz_dictgets(params, "Colors"); - if (obj) p->colors = fz_toint(obj); - - obj = fz_dictgets(params, "BitsPerComponent"); - if (obj) p->bpc = fz_toint(obj); - - p->stride = (p->bpc * p->colors * p->columns + 7) / 8; - p->bpp = (p->bpc * p->colors + 7) / 8; - - if (p->predictor >= 10) { - p->ref = fz_malloc(p->stride); - if (!p->ref) { fz_free(p); return fz_outofmem; } - memset(p->ref, 0, p->stride); - } - else { - p->ref = nil; - } - - return nil; -} - -void -fz_droppredict(fz_filter *filter) -{ - fz_predict *p = (fz_predict*)filter; - fz_free(p->ref); -} - -static inline int -getcomponent(unsigned char *buf, int x, int bpc) -{ - switch (bpc) - { - case 1: return buf[x / 8] >> (7 - (x % 8)) & 0x01; - case 2: return buf[x / 4] >> ((3 - (x % 4)) * 2) & 0x03; - case 4: return buf[x / 2] >> ((1 - (x % 2)) * 4) & 0x0f; - case 8: return buf[x]; - } - return 0; -} - -static inline void -putcomponent(unsigned char *buf, int x, int bpc, int value) -{ - switch (bpc) - { - case 1: buf[x / 8] |= value << (7 - (x % 8)); break; - case 2: buf[x / 4] |= value << ((3 - (x % 4)) * 2); break; - case 4: buf[x / 2] |= value << ((1 - (x % 2)) * 4); break; - case 8: buf[x] = value; break; - } -} - -static inline int -paeth(int a, int b, int c) -{ - /* The definitions of ac and bc are correct, not a typo. */ - int ac = b - c, bc = a - c, abcc = ac + bc; - int pa = (ac < 0 ? -ac : ac); - int pb = (bc < 0 ? -bc : bc); - int pc = (abcc < 0 ? -abcc : abcc); - return pa <= pb && pa <= pc ? a : pb <= pc ? b : c; -} - -static inline void -none(fz_predict *p, unsigned char *in, unsigned char *out) -{ - memcpy(out, in, p->stride); -} - -static void -tiff(fz_predict *p, unsigned char *in, unsigned char *out) -{ - int left[MAXC]; - int i, k; - - for (k = 0; k < p->colors; k++) - left[k] = 0; - - for (i = 0; i < p->columns; i++) { - for (k = 0; k < p->colors; k++) { - int a = getcomponent(in, i * p->colors + k, p->bpc); - int b = p->encode ? a - left[k] : a + left[k]; - int c = b % (1 << p->bpc); - putcomponent(out, i * p->colors + k, p->bpc, c); - left[k] = p->encode ? a : c; - } - } -} - -static void -png(fz_predict *p, unsigned char *in, unsigned char *out, int predictor) -{ - int upleft[MAXC], left[MAXC], i, k; - - for (k = 0; k < p->bpp; k++) { - left[k] = 0; - upleft[k] = 0; - } - - if (p->encode) - { - for (k = 0, i = 0; i < p->stride; k = (k + 1) % p->bpp, i ++) - { - switch (predictor) - { - case 0: out[i] = in[i]; break; - case 1: out[i] = in[i] - left[k]; break; - case 2: out[i] = in[i] - p->ref[i]; break; - case 3: out[i] = in[i] - (left[k] + p->ref[i]) / 2; break; - case 4: out[i] = in[i] - paeth(left[k], p->ref[i], upleft[k]); break; - } - left[k] = in[i]; - upleft[k] = p->ref[i]; - } - } - - else - { - for (k = 0, i = 0; i < p->stride; k = (k + 1) % p->bpp, i ++) - { - switch (predictor) - { - case 0: out[i] = in[i]; break; - case 1: out[i] = in[i] + left[k]; break; - case 2: out[i] = in[i] + p->ref[i]; break; - case 3: out[i] = in[i] + (left[k] + p->ref[i]) / 2; break; - case 4: out[i] = in[i] + paeth(left[k], p->ref[i], upleft[k]); break; - } - left[k] = out[i]; - upleft[k] = p->ref[i]; - } - } -} - -fz_error * -fz_processpredict(fz_filter *filter, fz_buffer *in, fz_buffer *out) -{ - fz_predict *dec = (fz_predict*)filter; - int ispng = dec->predictor >= 10; - int predictor; - - while (1) - { - if (in->rp + dec->stride + (!dec->encode && ispng) > in->wp) { - if (in->eof) - return fz_iodone; - return fz_ioneedin; - } - - if (out->wp + dec->stride + (dec->encode && ispng) > out->ep) - return fz_ioneedout; - - if (dec->predictor == 1) { - none(dec, in->rp, out->wp); - } - else if (dec->predictor == 2) { - if (dec->bpc != 8) - memset(out->wp, 0, dec->stride); - tiff(dec, in->rp, out->wp); - } - else { - if (dec->encode) { - predictor = dec->predictor - 10; - if (predictor < 0 || predictor > 4) - predictor = 1; - *out->wp ++ = predictor; - } - else { - predictor = *in->rp++; - } - png(dec, in->rp, out->wp, predictor); - } - - if (dec->ref) - memcpy(dec->ref, out->wp, dec->stride); - - in->rp += dec->stride; - out->wp += dec->stride; - } -} - -fz_error * -fz_newpredictd(fz_filter **fp, fz_obj *params) -{ - return fz_newpredict(fp, params, 0); -} - -fz_error * -fz_newpredicte(fz_filter **fp, fz_obj *params) -{ - return fz_newpredict(fp, params, 1); -} - |