From cc965300cb504ce452df1d37041b81c6ee6a5964 Mon Sep 17 00:00:00 2001
From: Aneesh Dogra <lionaneesh@gmail.com>
Date: Fri, 23 Mar 2012 23:24:00 +0530
Subject: [PATCH] sunrast: Add support for negative linesize.
Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>
---
libavcodec/sunrastenc.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/libavcodec/sunrastenc.c b/libavcodec/sunrastenc.c
index a9b47497585..1ed1d6eddbb 100644
--- a/libavcodec/sunrastenc.c
+++ b/libavcodec/sunrastenc.c
@@ -83,15 +83,18 @@ static void sunrast_image_write_image(AVCodecContext *avctx,
if (s->type == RT_BYTE_ENCODED) {
uint8_t value, value2;
int run;
- const uint8_t *end = pixels + avctx->height * linesize;
+ const uint8_t *start = linesize < 0 ? pixels + (avctx->height - 1) * linesize
+ : pixels;
+ const uint8_t *end = linesize < 0 ? pixels - linesize
+ : pixels + avctx->height * linesize;
ptr = pixels;
-#define GET_VALUE ptr >= end ? 0 : x >= len ? ptr[len-1] : ptr[x]
+#define GET_VALUE ptr >= end || ptr < start ? 0 : x >= len ? ptr[len-1] : ptr[x]
x = 0;
value2 = GET_VALUE;
- while (ptr < end) {
+ while (ptr < end && ptr >= start) {
run = 1;
value = value2;
x++;
@@ -101,7 +104,7 @@ static void sunrast_image_write_image(AVCodecContext *avctx,
}
value2 = GET_VALUE;
- while (value2 == value && run < 256 && ptr < end) {
+ while (value2 == value && run < 256 && ptr < end && ptr >= start) {
x++;
run++;
if (x >= alen) {
--
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