avformat/dv: fix used dimension variables

Fixes null pointer dereference during seeking
Fixes Ticket4395

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

libavformat/dv.c

@@ -422,8 +422,8 @@ static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
                                int64_t timestamp, int flags)
 {
     // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
-    const AVDVProfile *sys = av_dv_codec_profile2(c->vst->codec->width, c->vst->codec->height,
-                                                 c->vst->codec->pix_fmt, c->vst->codec->time_base);
+    const AVDVProfile *sys = av_dv_codec_profile2(c->vst->codec->coded_width, c->vst->codec->coded_height,
+                                                  c->vst->codec->pix_fmt, c->vst->codec->time_base);
     int64_t offset;
     int64_t size       = avio_size(s->pb) - s->internal->data_offset;
     int64_t max_offset = ((size - 1) / sys->frame_size) * sys->frame_size;