From 5f84fbce08769fb21d8459b81e9aad53635008b7 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 5 Aug 2018 17:06:44 +0200 Subject: [PATCH] avcodec/gdv: Eliminate 50% of the reads in the first inner loop in rescale() Signed-off-by: Michael Niedermayer --- libavcodec/gdv.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/libavcodec/gdv.c b/libavcodec/gdv.c index 595d8ff4e4..aea15a88ef 100644 --- a/libavcodec/gdv.c +++ b/libavcodec/gdv.c @@ -85,9 +85,15 @@ static void rescale(GDVContext *gdv, uint8_t *dst, int w, int h, int scale_v, in int y = h - j - 1; uint8_t *dst1 = dst + PREAMBLE_SIZE + y * w; uint8_t *src1 = dst + PREAMBLE_SIZE + (y>>!!gdv->scale_h) * (w>>1); - for (x = w - 1; x >= 0; x--) { + + for (x = w - 1; x >= 0 && !(x&1); x--) { dst1[x] = src1[(x>>1)]; } + + for (x--; x >= 0; x-=2) { + dst1[x ] = + dst1[x+1] = src1[(x>>1)]; + } } } else if (gdv->scale_h) { for (j = 0; j < h; j++) {