From 9e36d9e4ed2a43c363a54d963eb399a6e9623365 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 3 Jan 2013 23:40:22 +0100 Subject: [PATCH] pngdec: fix decoding of right column for 2/4bpp Fixes Ticket1146 Signed-off-by: Michael Niedermayer --- libavcodec/pngdec.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c index eb6e1a6713..21b742c850 100644 --- a/libavcodec/pngdec.c +++ b/libavcodec/pngdec.c @@ -784,15 +784,22 @@ static int decode_frame(AVCodecContext *avctx, int i, j; uint8_t *pd = s->current_picture->data[0]; for(j=0; j < s->height; j++) { + i = s->width/4; if (s->color_type == PNG_COLOR_TYPE_PALETTE){ - for(i=s->width/4-1; i>=0; i--) { + if ((s->width&3) >= 3) pd[4*i+2]= (pd[i]>>2)&3; + if ((s->width&3) >= 2) pd[4*i+1]= (pd[i]>>4)&3; + if ((s->width&3) >= 1) pd[4*i+0]= pd[i]>>6; + for(i--; i>=0; i--) { pd[4*i+3]= pd[i] &3; pd[4*i+2]= (pd[i]>>2)&3; pd[4*i+1]= (pd[i]>>4)&3; pd[4*i+0]= pd[i]>>6; } } else { - for(i=s->width/4-1; i>=0; i--) { + if ((s->width&3) >= 3) pd[4*i+2]= ((pd[i]>>2)&3)*0x55; + if ((s->width&3) >= 2) pd[4*i+1]= ((pd[i]>>4)&3)*0x55; + if ((s->width&3) >= 1) pd[4*i+0]= ( pd[i]>>6 )*0x55; + for(i--; i>=0; i--) { pd[4*i+3]= ( pd[i] &3)*0x55; pd[4*i+2]= ((pd[i]>>2)&3)*0x55; pd[4*i+1]= ((pd[i]>>4)&3)*0x55; @@ -806,13 +813,16 @@ static int decode_frame(AVCodecContext *avctx, int i, j; uint8_t *pd = s->current_picture->data[0]; for(j=0; j < s->height; j++) { + i=s->width/2; if (s->color_type == PNG_COLOR_TYPE_PALETTE){ - for(i=s->width/2-1; i>=0; i--) { + if (s->width&1) pd[2*i+0]= pd[i]>>4; + for(i--; i>=0; i--) { pd[2*i+1]= pd[i]&15; pd[2*i+0]= pd[i]>>4; } } else { - for(i=s->width/2-1; i>=0; i--) { + if (s->width&1) pd[2*i+0]= (pd[i]>>4)*0x11; + for(i--; i>=0; i--) { pd[2*i+1]= (pd[i]&15)*0x11; pd[2*i+0]= (pd[i]>>4)*0x11; }