diff --git a/ffmpeg.c b/ffmpeg.c
index 2d0f7f2aa8..720f8172ff 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -2107,19 +2107,6 @@ static int av_encode(AVFormatContext **output_files,
         ist->is_start = 1;
     }
 
-    /* set the duration of the output to the duration of the input
-     * if the output ends up being different, it'll be corrected later */
-    for (i=0;i<nb_output_files;i++) {
-        AVFormatContext *out_file = output_files[i];
-        AVFormatContext *in_file = input_files[i];
-
-        if (recording_time != INT64_MAX) {
-            out_file->duration = recording_time / 1000000 * AV_TIME_BASE;
-        } else {
-            out_file->duration = in_file->duration;
-        }
-    }
-
     /* set meta data information from input file if required */
     for (i=0;i<nb_meta_data_maps;i++) {
         AVFormatContext *out_file;