[FFmpeg-cvslog] lavfi/af_afir,af_aiir: Remove a variable that is always -1.

[Carl Eugen Hoyos]

ffmpeg | branch: master | Carl Eugen Hoyos <ceffmpeg at gmail.com> | Thu Jul 19 02:28:25 2018 +0200| [9cb3d8fcb7eb5b9b12a87ed27a2d7c4fc5416f85] | committer: Carl Eugen Hoyos

lavfi/af_afir,af_aiir: Remove a variable that is always -1.

Fixes two warnings:
libavfilter/af_afir.c:194:45: warning: assuming signed overflow does not occur when assuming that (X - c) > X is always false [-Wstrict-overflow]
     int dx = FFABS(x1-x0), sx = x0 < x1 ? 1 : -1;
                                 ~~~~~~~~~~~~^~~~
libavfilter/af_aiir.c:689:45: warning: assuming signed overflow does not occur when assuming that (X - c) > X is always false [-Wstrict-overflow]
     int dx = FFABS(x1-x0), sx = x0 < x1 ? 1 : -1;
                                 ~~~~~~~~~~~~^~~~

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9cb3d8fcb7eb5b9b12a87ed27a2d7c4fc5416f85
---

 libavfilter/af_afir.c | 4 ++--
 libavfilter/af_aiir.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/libavfilter/af_afir.c b/libavfilter/af_afir.c
index 75de14729d..a4a7160de1 100644
--- a/libavfilter/af_afir.c
+++ b/libavfilter/af_afir.c
@@ -191,7 +191,7 @@ static void drawtext(AVFrame *pic, int x, int y, const char *txt, uint32_t color
 
 static void draw_line(AVFrame *out, int x0, int y0, int x1, int y1, uint32_t color)
 {
-    int dx = FFABS(x1-x0), sx = x0 < x1 ? 1 : -1;
+    int dx = FFABS(x1-x0);
     int dy = FFABS(y1-y0), sy = y0 < y1 ? 1 : -1;
     int err = (dx>dy ? dx : -dy) / 2, e2;
 
@@ -205,7 +205,7 @@ static void draw_line(AVFrame *out, int x0, int y0, int x1, int y1, uint32_t col
 
         if (e2 >-dx) {
             err -= dy;
-            x0 += sx;
+            x0--;
         }
 
         if (e2 < dy) {
diff --git a/libavfilter/af_aiir.c b/libavfilter/af_aiir.c
index 65c8201137..9a4769c25f 100644
--- a/libavfilter/af_aiir.c
+++ b/libavfilter/af_aiir.c
@@ -686,7 +686,7 @@ static void drawtext(AVFrame *pic, int x, int y, const char *txt, uint32_t color
 
 static void draw_line(AVFrame *out, int x0, int y0, int x1, int y1, uint32_t color)
 {
-    int dx = FFABS(x1-x0), sx = x0 < x1 ? 1 : -1;
+    int dx = FFABS(x1-x0);
     int dy = FFABS(y1-y0), sy = y0 < y1 ? 1 : -1;
     int err = (dx>dy ? dx : -dy) / 2, e2;
 
@@ -700,7 +700,7 @@ static void draw_line(AVFrame *out, int x0, int y0, int x1, int y1, uint32_t col
 
         if (e2 >-dx) {
             err -= dy;
-            x0 += sx;
+            x0--;
         }
 
         if (e2 < dy) {