vf_gradfun: use the name 's' for the pointer to the private context

This is shorter and consistent across filters.

libavfilter/vf_gradfun.c

@@ -122,26 +122,26 @@ static void filter(GradFunContext *ctx, uint8_t *dst, uint8_t *src, int width, i
 
 static av_cold int init(AVFilterContext *ctx)
 {
-    GradFunContext *gf = ctx->priv;
+    GradFunContext *s = ctx->priv;
 
-    gf->thresh  = (1 << 15) / gf->strength;
-    gf->radius &= ~1;
+    s->thresh  = (1 << 15) / s->strength;
+    s->radius &= ~1;
 
-    gf->blur_line = ff_gradfun_blur_line_c;
-    gf->filter_line = ff_gradfun_filter_line_c;
+    s->blur_line = ff_gradfun_blur_line_c;
+    s->filter_line = ff_gradfun_filter_line_c;
 
     if (ARCH_X86)
-        ff_gradfun_init_x86(gf);
+        ff_gradfun_init_x86(s);
 
-    av_log(ctx, AV_LOG_VERBOSE, "threshold:%.2f radius:%d\n", gf->strength, gf->radius);
+    av_log(ctx, AV_LOG_VERBOSE, "threshold:%.2f radius:%d\n", s->strength, s->radius);
 
     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
-    GradFunContext *gf = ctx->priv;
-    av_freep(&gf->buf);
+    GradFunContext *s = ctx->priv;
+    av_freep(&s->buf);
 }
 
 static int query_formats(AVFilterContext *ctx)
@@ -161,25 +161,25 @@ static int query_formats(AVFilterContext *ctx)
 
 static int config_input(AVFilterLink *inlink)
 {
-    GradFunContext *gf = inlink->dst->priv;
+    GradFunContext *s = inlink->dst->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
     int hsub = desc->log2_chroma_w;
     int vsub = desc->log2_chroma_h;
 
-    gf->buf = av_mallocz((FFALIGN(inlink->w, 16) * (gf->radius + 1) / 2 + 32) * sizeof(uint16_t));
-    if (!gf->buf)
+    s->buf = av_mallocz((FFALIGN(inlink->w, 16) * (s->radius + 1) / 2 + 32) * sizeof(uint16_t));
+    if (!s->buf)
         return AVERROR(ENOMEM);
 
-    gf->chroma_w = -((-inlink->w) >> hsub);
-    gf->chroma_h = -((-inlink->h) >> vsub);
-    gf->chroma_r = av_clip(((((gf->radius >> hsub) + (gf->radius >> vsub)) / 2 ) + 1) & ~1, 4, 32);
+    s->chroma_w = -((-inlink->w) >> hsub);
+    s->chroma_h = -((-inlink->h) >> vsub);
+    s->chroma_r = av_clip(((((s->radius >> hsub) + (s->radius >> vsub)) / 2 ) + 1) & ~1, 4, 32);
 
     return 0;
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
-    GradFunContext *gf = inlink->dst->priv;
+    GradFunContext *s = inlink->dst->priv;
     AVFilterLink *outlink = inlink->dst->outputs[0];
     AVFrame *out;
     int p, direct;
@@ -203,15 +203,15 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
     for (p = 0; p < 4 && in->data[p]; p++) {
         int w = inlink->w;
         int h = inlink->h;
-        int r = gf->radius;
+        int r = s->radius;
         if (p) {
-            w = gf->chroma_w;
-            h = gf->chroma_h;
-            r = gf->chroma_r;
+            w = s->chroma_w;
+            h = s->chroma_h;
+            r = s->chroma_r;
         }
 
         if (FFMIN(w, h) > 2 * r)
-            filter(gf, out->data[p], in->data[p], w, h, out->linesize[p], in->linesize[p], r);
+            filter(s, out->data[p], in->data[p], w, h, out->linesize[p], in->linesize[p], r);
         else if (out->data[p] != in->data[p])
             av_image_copy_plane(out->data[p], out->linesize[p], in->data[p], in->linesize[p], w, h);
     }