avfilter/vf_eq: Move ff_nlmeans_init into a header

This removes a dependency of checkasm on lavfi/vf_eq.o
and also allows to inline ff_eq_init() irrespectively of
interposing.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavfilter/vf_eq.c

@@ -74,26 +74,6 @@ static void apply_lut(EQParameters *param, uint8_t *dst, int dst_stride,
     }
 }
 
-static void process_c(EQParameters *param, uint8_t *dst, int dst_stride,
-                      const uint8_t *src, int src_stride, int w, int h)
-{
-    int x, y, pel;
-
-    int contrast = (int) (param->contrast * 256 * 16);
-    int brightness = ((int) (100.0 * param->brightness + 100.0) * 511) / 200 - 128 - contrast / 32;
-
-    for (y = 0; y < h; y++) {
-        for (x = 0; x < w; x++) {
-            pel = ((src[y * src_stride + x] * contrast) >> 12) + brightness;
-
-            if (pel & ~255)
-                pel = (-pel) >> 31;
-
-            dst[y * dst_stride + x] = pel;
-        }
-    }
-}
-
 static void check_values(EQParameters *param, EQContext *eq)
 {
     if (param->contrast == 1.0 && param->brightness == 0.0 && param->gamma == 1.0)
@@ -174,13 +154,6 @@ static int set_expr(AVExpr **pexpr, const char *expr, const char *option, void *
     return 0;
 }
 
-void ff_eq_init(EQContext *eq)
-{
-    eq->process = process_c;
-    if (ARCH_X86)
-        ff_eq_init_x86(eq);
-}
-
 static int initialize(AVFilterContext *ctx)
 {
     EQContext *eq = ctx->priv;

libavfilter/vf_eq.h

@@ -100,7 +100,31 @@ typedef struct EQContext {
     enum EvalMode { EVAL_MODE_INIT, EVAL_MODE_FRAME, EVAL_MODE_NB } eval_mode;
 } EQContext;
 
-void ff_eq_init(EQContext *eq);
+static void process_c(EQParameters *param, uint8_t *dst, int dst_stride,
+                      const uint8_t *src, int src_stride, int w, int h)
+{
+    int contrast = (int) (param->contrast * 256 * 16);
+    int brightness = ((int) (100.0 * param->brightness + 100.0) * 511) / 200 - 128 - contrast / 32;
+
+    for (int y = 0; y < h; y++) {
+        for (int x = 0; x < w; x++) {
+            int pel = ((src[y * src_stride + x] * contrast) >> 12) + brightness;
+
+            if (pel & ~255)
+                pel = (-pel) >> 31;
+
+            dst[y * dst_stride + x] = pel;
+        }
+    }
+}
+
 void ff_eq_init_x86(EQContext *eq);
 
+static av_unused void ff_eq_init(EQContext *eq)
+{
+    eq->process = process_c;
+    if (ARCH_X86)
+        ff_eq_init_x86(eq);
+}
+
 #endif /* AVFILTER_EQ_H */