@@ -48,6 +48,7 @@ typedef struct HistogramContext {

     int            waveform_mode;

     int            display_mode;

     int            levels_mode;

+    const AVPixFmtDescriptor *desc;

 } HistogramContext;

 #define OFFSET(x) offsetof(HistogramContext, x)

@@ -117,9 +118,9 @@ static const uint8_t white_gbrp_color[4] = { 255, 255, 255, 255 };

 static int config_input(AVFilterLink *inlink)

 {

     HistogramContext *h = inlink->dst->priv;

-    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

-    h->ncomp = desc->nb_components;

+    h->desc  = av_pix_fmt_desc_get(inlink->format);

+    h->ncomp = h->desc->nb_components;

     switch (inlink->format) {

     case AV_PIX_FMT_GBRAP:

@@ -164,6 +165,41 @@ static int config_output(AVFilterLink *outlink)

     return 0;

 }

+static void gen_waveform(HistogramContext *h, AVFrame *inpicref, AVFrame *outpicref,

+                         int component, int intensity, int offset, int col_mode)

+{

+    const int plane = h->desc->comp[component].plane;

+    const int src_linesize = inpicref->linesize[plane];

+    const int dst_linesize = outpicref->linesize[plane];

+    uint8_t *src_data = inpicref->data[plane];

+    uint8_t *dst_data = outpicref->data[plane] + (col_mode ? offset * dst_linesize : offset);

+    uint8_t * const dst_line = dst_data;

+    const uint8_t max = 255 - intensity;

+    const int src_h = inpicref->height;

+    const int src_w = inpicref->width;

+    uint8_t *dst, *p;

+    int y;

+

+    for (y = 0; y < src_h; y++) {

+        const uint8_t *src_data_end = src_data + src_w;

+        dst = dst_line;

+        for (p = src_data; p < src_data_end; p++) {

+            uint8_t *target;

+            if (col_mode)

+                target = dst++ + dst_linesize * *p;

+            else

+                target = dst_data + *p;

+            if (*target <= max)

+                *target += intensity;

+            else

+                *target = 255;

+        }

+        src_data += src_linesize;

+        dst_data += dst_linesize;

+    }

+}

+

+

 static int filter_frame(AVFilterLink *inlink, AVFrame *in)

 {

     HistogramContext *h   = inlink->dst->priv;

@@ -227,34 +263,9 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)

         }

         break;

     case MODE_WAVEFORM:

-        if (h->waveform_mode) {

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

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

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

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

-                        int pos = (offset +

-                                   in->data[k][j * in->linesize[k] + i]) *

-                                  out->linesize[k] + i;

-                        unsigned value = out->data[k][pos];

-                        value = FFMIN(value + h->step, 255);

-                        out->data[k][pos] = value;

-                    }

-                }

-            }

-        } else {

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

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

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

-                    src = in ->data[k] + i * in ->linesize[k];

-                    dst = out->data[k] + i * out->linesize[k];

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

-                        int pos = src[j] + offset;

-                        unsigned value = dst[pos];

-                        value = FFMIN(value + h->step, 255);

-                        dst[pos] = value;

-                    }

-                }

-            }

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

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

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

         }

         break;

     case MODE_COLOR: