| Message ID | 20190803165739.GY3219@michaelspb |
|---|---|
| State | New |
| Headers | show |
lör 2019-08-03 klockan 18:57 +0200 skrev Michael Niedermayer: > On Sat, Aug 03, 2019 at 04:07:22PM +0200, Tomas Härdin wrote: > > lör 2019-08-03 klockan 01:49 +0200 skrev Michael Niedermayer: > > > - uint32_t x, y, src_x, src_y; > > > + uint32_t x, y, src_y; > > > + int width = hnm->width; > > > > > > for (y = 0; y < hnm->height; y++) { > > > + uint8_t *dst = hnm->processed + y * width; > > > + const uint8_t *src = hnm->current; > > > src_y = y - (y % 2); > > > - src_x = src_y * hnm->width + (y % 2); > > > - for (x = 0; x < hnm->width; x++) { > > > - hnm->processed[(y * hnm->width) + x] = hnm- > > > > current[src_x]; > > > - src_x += 2; > > > + src += src_y * width + (y % 2); > > > + for (x = 0; x < width; x++) { > > > + dst[x] = *src; > > > + src += 2; > > > > Looks OK. Maybe telling the compiler that src and dst don't alias > > would > > be worthwhile? > > i can add restrict keywords if you want: > ? > > diff --git a/libavcodec/hnm4video.c b/libavcodec/hnm4video.c > index 68d0baef6d..1c2501afab 100644 > --- a/libavcodec/hnm4video.c > +++ b/libavcodec/hnm4video.c > @@ -121,8 +121,8 @@ static void > postprocess_current_frame(AVCodecContext *avctx) > int width = hnm->width; > > for (y = 0; y < hnm->height; y++) { > - uint8_t *dst = hnm->processed + y * width; > - const uint8_t *src = hnm->current; > + uint8_t * restrict dst = hnm->processed + y * width; > + const uint8_t * restrict src = hnm->current; Does it improve performance? Else there's little point /Tomas
On Mon, Aug 05, 2019 at 11:58:01AM +0200, Tomas Härdin wrote: > lör 2019-08-03 klockan 18:57 +0200 skrev Michael Niedermayer: > > On Sat, Aug 03, 2019 at 04:07:22PM +0200, Tomas Härdin wrote: > > > lör 2019-08-03 klockan 01:49 +0200 skrev Michael Niedermayer: > > > > - uint32_t x, y, src_x, src_y; > > > > + uint32_t x, y, src_y; > > > > + int width = hnm->width; > > > > > > > > for (y = 0; y < hnm->height; y++) { > > > > + uint8_t *dst = hnm->processed + y * width; > > > > + const uint8_t *src = hnm->current; > > > > src_y = y - (y % 2); > > > > - src_x = src_y * hnm->width + (y % 2); > > > > - for (x = 0; x < hnm->width; x++) { > > > > - hnm->processed[(y * hnm->width) + x] = hnm- > > > > > current[src_x]; > > > > - src_x += 2; > > > > + src += src_y * width + (y % 2); > > > > + for (x = 0; x < width; x++) { > > > > + dst[x] = *src; > > > > + src += 2; > > > > > > Looks OK. Maybe telling the compiler that src and dst don't alias > > > would > > > be worthwhile? > > > > i can add restrict keywords if you want: > > ? > > > > diff --git a/libavcodec/hnm4video.c b/libavcodec/hnm4video.c > > index 68d0baef6d..1c2501afab 100644 > > --- a/libavcodec/hnm4video.c > > +++ b/libavcodec/hnm4video.c > > @@ -121,8 +121,8 @@ static void > > postprocess_current_frame(AVCodecContext *avctx) > > int width = hnm->width; > > > > for (y = 0; y < hnm->height; y++) { > > - uint8_t *dst = hnm->processed + y * width; > > - const uint8_t *src = hnm->current; > > + uint8_t * restrict dst = hnm->processed + y * width; > > + const uint8_t * restrict src = hnm->current; > > Does it improve performance? Else there's little point I cannot meassure a performance difference for it its within 1% thx [...]
diff --git a/libavcodec/hnm4video.c b/libavcodec/hnm4video.c index 68d0baef6d..1c2501afab 100644 --- a/libavcodec/hnm4video.c +++ b/libavcodec/hnm4video.c @@ -121,8 +121,8 @@ static void postprocess_current_frame(AVCodecContext *avctx) int width = hnm->width; for (y = 0; y < hnm->height; y++) { - uint8_t *dst = hnm->processed + y * width; - const uint8_t *src = hnm->current; + uint8_t * restrict dst = hnm->processed + y * width; + const uint8_t * restrict src = hnm->current; src_y = y - (y % 2); src += src_y * width + (y % 2); for (x = 0; x < width; x++) {