On Thu, Oct 10, 2019 at 03:18:26AM +0300, Skakov Pavel wrote: > Made it easier for compiler to optimize array indexes when unpacking YUV.
> tiff.c | 19 ++++++++++--------- > 1 file changed, 10 insertions(+), 9 deletions(-) > ab39e158e34253528edf4f3a2e90efb3a6e89d80 > 0004-avcodec-tiff-small-compiling-optimization.patch > From 29b2437e04d6af1c5093efcaac6f8bc852525d78 Mon Sep 17 00:00:00 2001 > From: Pavel Skakov <pave...@gmail.com> > Date: Thu, 10 Oct 2019 02:43:34 +0300 > Subject: [PATCH 4/4] avcodec/tiff: small compiling optimization > > Signed-off-by: Pavel Skakov <pave...@gmail.com> > --- > libavcodec/tiff.c | 19 ++++++++++--------- > 1 file changed, 10 insertions(+), 9 deletions(-) > > diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c > index be46db961c..71584b1c86 100644 > --- a/libavcodec/tiff.c > +++ b/libavcodec/tiff.c > @@ -358,11 +358,12 @@ static void unpack_gray(TiffContext *s, AVFrame *p, > } > } > > -static void unpack_yuv(TiffContext *s, AVFrame *p, > +static void unpack_yuv(TiffContext *av_restrict s, AVFrame *av_restrict p, > const uint8_t *src, int lnum) > { > - int i, j, k; > - int w = (s->width - 1) / s->subsampling[0] + 1; > + size_t i, j, k; > + size_t w = (s->width - 1) / s->subsampling[0] + 1; > + uint8_t *py = &p->data[0][lnum * p->linesize[0]]; > uint8_t *pu = &p->data[1][lnum / s->subsampling[1] * p->linesize[1]]; > uint8_t *pv = &p->data[2][lnum / s->subsampling[1] * p->linesize[2]]; > if (s->width % s->subsampling[0] || s->height % s->subsampling[1]) { > @@ -371,7 +372,7 @@ static void unpack_yuv(TiffContext *s, AVFrame *p, > for (j = 0; j < s->subsampling[1]; j++) > for (k = 0; k < s->subsampling[0]; k++) > if (j < s->height - lnum && i * s->subsampling[0] + > k < s->width) { > - p->data[0][(lnum + j) * p->linesize[0] + i * > s->subsampling[0] + k] = *src++; > + py[j * p->linesize[0] + i * s->subsampling[0] + > k] = *src++; > } else { > src++; > } > @@ -383,8 +384,8 @@ static void unpack_yuv(TiffContext *s, AVFrame *p, > for (j = 0; j < s->subsampling[1]; j++) > for (k = 0; k < s->subsampling[0]; k++) > if (j < s->height - lnum && i * s->subsampling[0] + > k < s->width) { > - p->data[0][(lnum + j) * p->linesize[0] + (i * > s->subsampling[0] + k)*2 ] = *src++; > - p->data[0][(lnum + j) * p->linesize[0] + (i * > s->subsampling[0] + k)*2 + 1] = *src++; > + py[j * p->linesize[0] + (i * s->subsampling[0] + > k)*2 ] = *src++; > + py[j * p->linesize[0] + (i * s->subsampling[0] + > k)*2 + 1] = *src++; maybe you want to eliminate all p-> / s-> dereferencing [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB In a rich man's house there is no place to spit but his face. -- Diogenes of Sinope
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