diff options
Diffstat (limited to 'fitz/filt_predict.c')
| -rw-r--r-- | fitz/filt_predict.c | 256 |
1 files changed, 0 insertions, 256 deletions
diff --git a/fitz/filt_predict.c b/fitz/filt_predict.c deleted file mode 100644 index c8de290a..00000000 --- a/fitz/filt_predict.c +++ /dev/null @@ -1,256 +0,0 @@ -#include "mupdf/fitz.h" - -/* TODO: check if this works with 16bpp images */ - -enum { MAXC = 32 }; - -typedef struct fz_predict_s fz_predict; - -struct fz_predict_s -{ - fz_stream *chain; - - int predictor; - int columns; - int colors; - int bpc; - - int stride; - int bpp; - unsigned char *in; - unsigned char *out; - unsigned char *ref; - unsigned char *rp, *wp; -}; - -static inline int getcomponent(unsigned char *line, int x, int bpc) -{ - switch (bpc) - { - case 1: return (line[x >> 3] >> ( 7 - (x & 7) ) ) & 1; - case 2: return (line[x >> 2] >> ( ( 3 - (x & 3) ) << 1 ) ) & 3; - case 4: return (line[x >> 1] >> ( ( 1 - (x & 1) ) << 2 ) ) & 15; - case 8: return line[x]; - case 16: return (line[x<<1]<<8)+line[(x<<1)+1]; - } - return 0; -} - -static inline void putcomponent(unsigned char *buf, int x, int bpc, int value) -{ - switch (bpc) - { - case 1: buf[x >> 3] |= value << (7 - (x & 7)); break; - case 2: buf[x >> 2] |= value << ((3 - (x & 3)) << 1); break; - case 4: buf[x >> 1] |= value << ((1 - (x & 1)) << 2); break; - case 8: buf[x] = value; break; - case 16: buf[x<<1] = value>>8; buf[(x<<1)+1] = 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 = fz_absi(ac); - int pb = fz_absi(bc); - int pc = fz_absi(abcc); - return pa <= pb && pa <= pc ? a : pb <= pc ? b : c; -} - -static void -fz_predict_tiff(fz_predict *state, unsigned char *out, unsigned char *in, int len) -{ - int left[MAXC]; - int i, k; - const int mask = (1 << state->bpc)-1; - - for (k = 0; k < state->colors; k++) - left[k] = 0; - memset(out, 0, state->stride); - - for (i = 0; i < state->columns; i++) - { - for (k = 0; k < state->colors; k++) - { - int a = getcomponent(in, i * state->colors + k, state->bpc); - int b = a + left[k]; - int c = b & mask; - putcomponent(out, i * state->colors + k, state->bpc, c); - left[k] = c; - } - } -} - -static void -fz_predict_png(fz_predict *state, unsigned char *out, unsigned char *in, int len, int predictor) -{ - int bpp = state->bpp; - int i; - unsigned char *ref = state->ref; - - switch (predictor) - { - case 0: - memcpy(out, in, len); - break; - case 1: - for (i = bpp; i > 0; i--) - { - *out++ = *in++; - } - for (i = len - bpp; i > 0; i--) - { - *out = *in++ + out[-bpp]; - out++; - } - break; - case 2: - for (i = bpp; i > 0; i--) - { - *out++ = *in++ + *ref++; - } - for (i = len - bpp; i > 0; i--) - { - *out++ = *in++ + *ref++; - } - break; - case 3: - for (i = bpp; i > 0; i--) - { - *out++ = *in++ + (*ref++) / 2; - } - for (i = len - bpp; i > 0; i--) - { - *out = *in++ + (out[-bpp] + *ref++) / 2; - out++; - } - break; - case 4: - for (i = bpp; i > 0; i--) - { - *out++ = *in++ + paeth(0, *ref++, 0); - } - for (i = len - bpp; i > 0; i --) - { - *out = *in++ + paeth(out[-bpp], *ref, ref[-bpp]); - ref++; - out++; - } - break; - } -} - -static int -read_predict(fz_stream *stm, unsigned char *buf, int len) -{ - fz_predict *state = stm->state; - unsigned char *p = buf; - unsigned char *ep = buf + len; - int ispng = state->predictor >= 10; - int n; - - while (state->rp < state->wp && p < ep) - *p++ = *state->rp++; - - while (p < ep) - { - n = fz_read(state->chain, state->in, state->stride + ispng); - if (n == 0) - return p - buf; - - if (state->predictor == 1) - memcpy(state->out, state->in, n); - else if (state->predictor == 2) - fz_predict_tiff(state, state->out, state->in, n); - else - { - fz_predict_png(state, state->out, state->in + 1, n - 1, state->in[0]); - memcpy(state->ref, state->out, state->stride); - } - - state->rp = state->out; - state->wp = state->out + n - ispng; - - while (state->rp < state->wp && p < ep) - *p++ = *state->rp++; - } - - return p - buf; -} - -static void -close_predict(fz_context *ctx, void *state_) -{ - fz_predict *state = (fz_predict *)state_; - fz_close(state->chain); - fz_free(ctx, state->in); - fz_free(ctx, state->out); - fz_free(ctx, state->ref); - fz_free(ctx, state); -} - -/* Default values: predictor = 1, columns = 1, colors = 1, bpc = 8 */ -fz_stream * -fz_open_predict(fz_stream *chain, int predictor, int columns, int colors, int bpc) -{ - fz_context *ctx = chain->ctx; - fz_predict *state = NULL; - - fz_var(state); - - if (predictor < 1) - predictor = 1; - if (columns < 1) - columns = 1; - if (colors < 1) - colors = 1; - if (bpc < 1) - bpc = 8; - - fz_try(ctx) - { - state = fz_malloc_struct(ctx, fz_predict); - state->in = NULL; - state->out = NULL; - state->chain = chain; - - state->predictor = predictor; - state->columns = columns; - state->colors = colors; - state->bpc = bpc; - - if (state->predictor != 1 && state->predictor != 2 && - state->predictor != 10 && state->predictor != 11 && - state->predictor != 12 && state->predictor != 13 && - state->predictor != 14 && state->predictor != 15) - { - fz_warn(ctx, "invalid predictor: %d", state->predictor); - state->predictor = 1; - } - - state->stride = (state->bpc * state->colors * state->columns + 7) / 8; - state->bpp = (state->bpc * state->colors + 7) / 8; - - state->in = fz_malloc(ctx, state->stride + 1); - state->out = fz_malloc(ctx, state->stride); - state->ref = fz_malloc(ctx, state->stride); - state->rp = state->out; - state->wp = state->out; - - memset(state->ref, 0, state->stride); - } - fz_catch(ctx) - { - if (state) - { - fz_free(ctx, state->in); - fz_free(ctx, state->out); - } - fz_free(ctx, state); - fz_close(chain); - fz_rethrow(ctx); - } - - return fz_new_stream(ctx, state, read_predict, close_predict); -} |