@@ -77,6 +77,7 @@ typedef struct {

     float gain;

     int hop_size;

     float *combine_buffer;      ///< color combining buffer (3 * h items)

+    float **color_buffer;       ///< color buffer (3 * h * ch items)

     AVAudioFifo *fifo;

     int64_t pts;

     int single_pic;

@@ -230,12 +231,17 @@ static av_cold void uninit(AVFilterContext *ctx)

         for (i = 0; i < s->nb_display_channels; i++)

             av_fft_end(s->fft[i]);

     }

+    av_freep(&s->fft);

     if (s->fft_data) {

         for (i = 0; i < s->nb_display_channels; i++)

             av_freep(&s->fft_data[i]);

     }

-    av_freep(&s->fft);

     av_freep(&s->fft_data);

+    if (s->color_buffer) {

+        for (i = 0; i < s->nb_display_channels; i++)

+            av_freep(&s->color_buffer[i]);

+    }

+    av_freep(&s->color_buffer);

     av_freep(&s->window_func_lut);

     if (s->magnitudes) {

         for (i = 0; i < s->nb_display_channels; i++)

@@ -366,6 +372,16 @@ static int config_output(AVFilterLink *outlink)

                 return AVERROR(ENOMEM);

         }

+        av_freep(&s->color_buffer);

+        s->color_buffer = av_calloc(s->nb_display_channels, sizeof(*s->color_buffer));

+        if (!s->color_buffer)

+            return AVERROR(ENOMEM);

+        for (i = 0; i < s->nb_display_channels; i++) {

+            s->color_buffer[i] = av_malloc_array(s->orientation == VERTICAL ? s->h * 3 : s->w * 3, sizeof(**s->color_buffer));

+            if (!s->color_buffer[i])

+                return AVERROR(ENOMEM);

+        }

+

         s->fft_data = av_calloc(s->nb_display_channels, sizeof(*s->fft_data));

         if (!s->fft_data)

             return AVERROR(ENOMEM);

@@ -613,13 +629,13 @@ static void pick_color(ShowSpectrumContext *s,

               + color_table[cm][i].v * lerpfrac;

         }

-        out[0] += y * yf;

-        out[1] += u * uf;

-        out[2] += v * vf;

+        out[0] = y * yf;

+        out[1] = u * uf;

+        out[2] = v * vf;

     } else {

-        out[0] += a * yf;

-        out[1] += a * uf;

-        out[2] += a * vf;

+        out[0] = a * yf;

+        out[1] = a * uf;

+        out[2] = a * vf;

     }

 }

@@ -650,7 +666,7 @@ static int plot_channel(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)

     /* draw the channel */

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

         int row = (s->mode == COMBINED) ? y : ch * h + y;

-        float *out = &s->combine_buffer[3 * row];

+        float *out = &s->color_buffer[ch][3 * row];

         float a;

         switch (s->data) {

@@ -702,14 +718,21 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFrame *insamples)

     AVFilterLink *outlink = ctx->outputs[0];

     ShowSpectrumContext *s = ctx->priv;

     AVFrame *outpicref = s->outpicref;

-    int ret, plane, x, y;

+    int ret, plane, x, y, z = s->orientation == VERTICAL ? s->h : s->w;

     /* fill a new spectrum column */

     /* initialize buffer for combining to black */

-    clear_combine_buffer(s, s->orientation == VERTICAL ? s->h : s->w);

+    clear_combine_buffer(s, z);

     ctx->internal->execute(ctx, plot_channel, NULL, NULL, s->nb_display_channels);

+    for (y = 0; y < z * 3; y++) {

+        s->combine_buffer[y] += s->color_buffer[0][y];

+        for (x = 1; x < s->nb_display_channels; x++) {

+            s->combine_buffer[y] += s->color_buffer[x][y];

+        }

+    }

+

     av_frame_make_writable(s->outpicref);

     /* copy to output */

     if (s->orientation == VERTICAL) {