@@ -247,9 +247,9 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)

     out->pts = in->pts;

     for (k = 0; k < h->ncomp; k++) {

-        int is_chroma = (k == 1 || k == 2);

-        int dst_h = FF_CEIL_RSHIFT(outlink->h, (is_chroma ? h->desc->log2_chroma_h : 0));

-        int dst_w = FF_CEIL_RSHIFT(outlink->w, (is_chroma ? h->desc->log2_chroma_w : 0));

+        const int is_chroma = (k == 1 || k == 2);

+        const int dst_h = FF_CEIL_RSHIFT(outlink->h, (is_chroma ? h->desc->log2_chroma_h : 0));

+        const int dst_w = FF_CEIL_RSHIFT(outlink->w, (is_chroma ? h->desc->log2_chroma_w : 0));

         for (i = 0; i < dst_h ; i++)

             memset(out->data[h->desc->comp[k].plane] +

                    i * out->linesize[h->desc->comp[k].plane],

@@ -260,7 +260,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)

     case MODE_LEVELS:

         for (k = 0; k < h->ncomp; k++) {

             const int p = h->desc->comp[k].plane;

-            int start = k * (h->level_height + h->scale_height) * h->display_mode;

+            const int start = k * (h->level_height + h->scale_height) * h->display_mode;

             double max_hval_log;

             unsigned max_hval = 0;

@@ -299,16 +299,16 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)

         break;

     case MODE_WAVEFORM:

         for (k = 0; k < h->ncomp; k++) {

-            int offset = k * 256 * h->display_mode;

+            const int offset = k * 256 * h->display_mode;

             gen_waveform(h, in, out, k, h->step, offset, h->waveform_mode);

         }

         break;

     case MODE_COLOR:

         for (i = 0; i < inlink->h; i++) {

-            int iw1 = i * in->linesize[1];

-            int iw2 = i * in->linesize[2];

+            const int iw1 = i * in->linesize[1];

+            const int iw2 = i * in->linesize[2];

             for (j = 0; j < inlink->w; j++) {

-                int pos = in->data[1][iw1 + j] * out->linesize[0] + in->data[2][iw2 + j];

+                const int pos = in->data[1][iw1 + j] * out->linesize[0] + in->data[2][iw2 + j];

                 if (out->data[0][pos] < 255)

                     out->data[0][pos]++;

             }

@@ -325,12 +325,12 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)

         break;

     case MODE_COLOR2:

         for (i = 0; i < inlink->h; i++) {

-            int iw1 = i * in->linesize[1];

-            int iw2 = i * in->linesize[2];

+            const int iw1 = i * in->linesize[1];

+            const int iw2 = i * in->linesize[2];

             for (j = 0; j < inlink->w; j++) {

-                int u = in->data[1][iw1 + j];

-                int v = in->data[2][iw2 + j];

-                int pos = u * out->linesize[0] + v;

+                const int u = in->data[1][iw1 + j];

+                const int v = in->data[2][iw2 + j];

+                const int pos = u * out->linesize[0] + v;

                 if (!out->data[0][pos])

                     out->data[0][pos] = FFABS(128 - u) + FFABS(128 - v);

                 out->data[1][pos] = u;