Merge commit '22de0f8369f1f3edf1a55e1d275f3c07c617b53e'

* commit '22de0f8369f1f3edf1a55e1d275f3c07c617b53e':
  mov: Compute max duration among the tracks with a timescale

Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/movenc.c

@@ -1877,7 +1877,7 @@ static int mov_write_mvhd_tag(AVIOContext *pb, MOVMuxContext *mov)
     int version;
 
     for (i = 0; i < mov->nb_streams; i++) {
-        if (mov->tracks[i].entry > 0) {
+        if (mov->tracks[i].entry > 0 && mov->tracks[i].timescale) {
             max_track_len_temp = av_rescale_rnd(mov->tracks[i].track_duration,
                                                 MOV_TIMESCALE,
                                                 mov->tracks[i].timescale,