vqa: set stream start_time to 0.

The format has no coded timestamps and must use packet durations to generate
them.

libavformat/westwood_vqa.c

@@ -94,6 +94,7 @@ static int wsvqa_read_header(AVFormatContext *s,
     st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);
+    st->start_time = 0;
     avpriv_set_pts_info(st, 33, 1, VQA_FRAMERATE);
     wsvqa->video_stream_index = st->index;
     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
@@ -120,6 +121,7 @@ static int wsvqa_read_header(AVFormatContext *s,
         st = avformat_new_stream(s, NULL);
         if (!st)
             return AVERROR(ENOMEM);
+        st->start_time = 0;
         avpriv_set_pts_info(st, 33, 1, VQA_FRAMERATE);
         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
         if (AV_RL16(&header[0]) == 1)