X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavfilter%2Faf_pan.c;h=34e522c9d4eb2bf1923f38458c64d06ebe3c96c0;hb=492b312ddd855ecb9334960b9602086937196e76;hp=23b29419b635027889bff8340547028449664660;hpb=5b5365fe9d635005a9020d89c2448f4b5828d42f;p=ffmpeg

diff --git a/libavfilter/af_pan.c b/libavfilter/af_pan.c
index 23b29419b63..34e522c9d4e 100644
--- a/libavfilter/af_pan.c
+++ b/libavfilter/af_pan.c
@@ -104,6 +104,7 @@ static av_cold int init(AVFilterContext *ctx)
     char *arg, *arg0, *tokenizer, *args = av_strdup(pan->args);
     int out_ch_id, in_ch_id, len, named, ret, sign = 1;
     int nb_in_channels[2] = { 0, 0 }; // number of unnamed and named input channels
+    int used_out_ch[MAX_CHANNELS] = {0};
     double gain;
 
     if (!pan->args) {
@@ -127,6 +128,7 @@ static av_cold int init(AVFilterContext *ctx)
 
     /* parse channel specifications */
     while ((arg = arg0 = av_strtok(NULL, "|", &tokenizer))) {
+        int used_in_ch[MAX_CHANNELS] = {0};
         /* channel name */
         if (parse_channel_name(&arg, &out_ch_id, &named)) {
             av_log(ctx, AV_LOG_ERROR,
@@ -153,6 +155,13 @@ static av_cold int init(AVFilterContext *ctx)
             ret = AVERROR(EINVAL);
             goto fail;
         }
+        if (used_out_ch[out_ch_id]) {
+            av_log(ctx, AV_LOG_ERROR,
+                   "Can not reference out channel %d twice\n", out_ch_id);
+            ret = AVERROR(EINVAL);
+            goto fail;
+        }
+        used_out_ch[out_ch_id] = 1;
         skip_spaces(&arg);
         if (*arg == '=') {
             arg++;
@@ -166,6 +175,7 @@ static av_cold int init(AVFilterContext *ctx)
             goto fail;
         }
         /* gains */
+        sign = 1;
         while (1) {
             gain = 1;
             if (sscanf(arg, "%lf%n *%n", &gain, &len, &len))
@@ -183,6 +193,13 @@ static av_cold int init(AVFilterContext *ctx)
                 ret = AVERROR(EINVAL);
                 goto fail;
             }
+            if (used_in_ch[in_ch_id]) {
+                av_log(ctx, AV_LOG_ERROR,
+                       "Can not reference in channel %d twice\n", in_ch_id);
+                ret = AVERROR(EINVAL);
+                goto fail;
+            }
+            used_in_ch[in_ch_id] = 1;
             pan->gain[out_ch_id][in_ch_id] = sign * gain;
             skip_spaces(&arg);
             if (!*arg)