diff options
| -rw-r--r-- | fitz/filt_predict.c | 83 |
1 files changed, 44 insertions, 39 deletions
diff --git a/fitz/filt_predict.c b/fitz/filt_predict.c index 17242742..48273236 100644 --- a/fitz/filt_predict.c +++ b/fitz/filt_predict.c @@ -119,13 +119,13 @@ paeth(int a, int b, int c) } static inline void -fz_predictnone(fz_predict *p, unsigned char *in, unsigned char *out) +fz_predictnone(fz_predict *p, unsigned char *in, int len, unsigned char *out) { - memcpy(out, in, p->stride); + memcpy(out, in, len); } static void -fz_predicttiff(fz_predict *p, unsigned char *in, unsigned char *out) +fz_predicttiff(fz_predict *p, unsigned char *in, int len, unsigned char *out) { int left[MAXC]; int i, k; @@ -147,7 +147,7 @@ fz_predicttiff(fz_predict *p, unsigned char *in, unsigned char *out) } static void -fz_predictpng(fz_predict *p, unsigned char *in, unsigned char *out, int predictor) +fz_predictpng(fz_predict *p, unsigned char *in, int len, unsigned char *out, int predictor) { int bpp = p->bpp; int i; @@ -156,14 +156,14 @@ fz_predictpng(fz_predict *p, unsigned char *in, unsigned char *out, int predicto switch (predictor) { case 0: - memcpy(out, in, p->stride); + memcpy(out, in, len); break; case 1: for (i = bpp; i > 0; i--) { *out++ = *in++; } - for (i = p->stride - bpp; i > 0; i--) + for (i = len - bpp; i > 0; i--) { *out = *in++ + out[-bpp]; out++; @@ -174,7 +174,7 @@ fz_predictpng(fz_predict *p, unsigned char *in, unsigned char *out, int predicto { *out++ = *in++ + *ref++; } - for (i = p->stride - bpp; i > 0; i--) + for (i = len - bpp; i > 0; i--) { *out++ = *in++ + *ref++; } @@ -184,7 +184,7 @@ fz_predictpng(fz_predict *p, unsigned char *in, unsigned char *out, int predicto { *out++ = *in++ + (*ref++) / 2; } - for (i = p->stride - bpp; i > 0; i--) + for (i = len - bpp; i > 0; i--) { *out = *in++ + (out[-bpp] + *ref++)/2; out++; @@ -195,7 +195,7 @@ fz_predictpng(fz_predict *p, unsigned char *in, unsigned char *out, int predicto { *out++ = *in++ + paeth(0, *ref++, 0); } - for (i = p->stride - bpp; i > 0; i --) + for (i = len - bpp; i > 0; i --) { *out = *in++ + paeth(out[-bpp], *ref, ref[-bpp]); ref++; @@ -209,54 +209,59 @@ fz_error fz_processpredict(fz_filter *filter, fz_buffer *in, fz_buffer *out) { fz_predict *dec = (fz_predict*)filter; + int remaining, toconsume, toproduce; int ispng = dec->predictor >= 10; - int predictor; dec->ref = dec->refbuf; while (1) { - if (in->rp + dec->stride + ispng > in->wp) + remaining = in->wp - in->rp; + toconsume = MIN(remaining, dec->stride + ispng); + toproduce = MIN(remaining - ispng, dec->stride); + + if (remaining < dec->stride + ispng && !in->eof) { - if (in->eof) - return fz_iodone; - if (dec->refbuf != dec->ref) - { - memcpy(dec->refbuf, dec->ref, dec->stride); - } return fz_ioneedin; } - if (out->wp + dec->stride > out->ep) + if (out->wp + toproduce > out->ep) { - if (dec->refbuf != dec->ref) - { - memcpy(dec->refbuf, dec->ref, dec->stride); - } return fz_ioneedout; } - if (dec->predictor == 1) - { - fz_predictnone(dec, in->rp, out->wp); - } - else if (dec->predictor == 2) - { - if (dec->bpc != 8) - memset(out->wp, 0, dec->stride); - fz_predicttiff(dec, in->rp, out->wp); - } - else + if (toconsume > 0) { - predictor = *in->rp++; - fz_predictpng(dec, in->rp, out->wp, predictor); + if (dec->predictor == 1) + { + fz_predictnone(dec, in->rp, toconsume, out->wp); + } + else if (dec->predictor == 2) + { + if (dec->bpc != 8) + memset(out->wp, 0, toconsume); + fz_predicttiff(dec, in->rp, toconsume, out->wp); + } + else + { + int predictor = *in->rp++; + toconsume -= ispng; + fz_predictpng(dec, in->rp, toconsume, out->wp, predictor); + } + + if (dec->refbuf) + { + memcpy(dec->refbuf, out->wp, toproduce); + dec->ref = dec->refbuf; + } + + in->rp += toconsume; + out->wp += toproduce; } - if (dec->refbuf) + if (in->eof && (in->wp - in->rp <= 0)) { - dec->ref = out->wp; + return fz_iodone; } - in->rp += dec->stride; - out->wp += dec->stride; } } |