avfilter/af_compand: do not clip; allow >0dB curve points

Do not clip output samples, so that clipping can be handled by other filters.
Alow setting curve points above 0dB. This is useful when operating with floats.
Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavfilter/af_compand.c

@@ -205,7 +205,7 @@ static int compand_nodelay(AVFilterContext *ctx, AVFrame *frame)
         for (i = 0; i < nb_samples; i++) {
             update_volume(cp, fabs(src[i]));
 
-            dst[i] = av_clipd(src[i] * get_volume(s, cp->volume), -1, 1);
+            dst[i] = src[i] * get_volume(s, cp->volume);
         }
     }
 
@@ -266,8 +266,7 @@ static int compand_delay(AVFilterContext *ctx, AVFrame *frame)
                 }
 
                 dst = (double *)out_frame->extended_data[chan];
-                dst[oindex++] = av_clipd(dbuf[dindex] *
-                        get_volume(s, cp->volume), -1, 1);
+                dst[oindex++] = dbuf[dindex] * get_volume(s, cp->volume);
             } else {
                 count++;
             }
@@ -315,8 +314,7 @@ static int compand_drain(AVFilterLink *outlink)
 
         dindex = s->delay_index;
         for (i = 0; i < frame->nb_samples; i++) {
-            dst[i] = av_clipd(dbuf[dindex] * get_volume(s, cp->volume),
-                    -1, 1);
+            dst[i] = dbuf[dindex] * get_volume(s, cp->volume);
             dindex = MOD(dindex + 1, s->delay_samples);
         }
     }
@@ -450,14 +448,14 @@ static int config_output(AVFilterLink *outlink)
             S(j) = S(j + 1);
     }
 
-    for (i = 0; !i || s->segments[i - 2].x; i += 2) {
+    for (i = 0; i < s->nb_segments; i += 2) {
         s->segments[i].y += s->gain_dB;
         s->segments[i].x *= M_LN10 / 20;
         s->segments[i].y *= M_LN10 / 20;
     }
 
 #define L(x) s->segments[i - (x)]
-    for (i = 4; s->segments[i - 2].x; i += 2) {
+    for (i = 4; i < s->nb_segments; i += 2) {
         double x, y, cx, cy, in1, in2, out1, out2, theta, len, r;
 
         L(4).a = 0;