From ffa1de8a3b93139097214bc600d356ab62bfdf05 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 24 Jun 2015 17:07:27 +0200 Subject: [PATCH] avcodec/jpeg2000dec: Use 32x32->64bit for 9/7i dequantization Like the 5/3 case this is needed to avoid overflows and similarly for 16bpp output pure 32bit operations are insufficient if high quality is wanted Note, this code-path is only used in bitexact mode, so this should not affect the speed of any real use-case Signed-off-by: Michael Niedermayer --- libavcodec/jpeg2000dec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c index 11f4cd6ff6..43568ea0eb 100644 --- a/libavcodec/jpeg2000dec.c +++ b/libavcodec/jpeg2000dec.c @@ -1457,7 +1457,7 @@ static void dequantization_int_97(int x, int y, Jpeg2000Cblk *cblk, int32_t *datap = &comp->i_data[(comp->coord[0][1] - comp->coord[0][0]) * (y + j) + x]; int *src = t1->data[j]; for (i = 0; i < w; ++i) - datap[i] = (src[i] * band->i_stepsize + (1<<14)) >> 15; + datap[i] = (src[i] * (int64_t)band->i_stepsize + (1<<14)) >> 15; } }