lavf/dv: make returning the video packet optional

The mov demuxer only returns DV audio, video packets are discarded.

It first reads the data to be parsed into a packet. Then both this
packet and the pointer to its data are passed together to
avpriv_dv_produce_packet(), which parses the data and partially
overwrites the packet. This is confusing and potentially dangerous, so
just pass NULL and avoid pointless packet modification.

1 files changed, 11 insertions, 8 deletions

diff --git a/libavformat/dv.c b/libavformat/dv.c
index 303cecf9bb..f88fe62349 100644
--- a/libavformat/dv.c
+++ b/libavformat/dv.c
@@ -430,14 +430,17 @@ int avpriv_dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
         }
     }
 
-    /* Now it's time to return video packet */
-    size = dv_extract_video_info(c, buf);
-    pkt->data         = buf;
-    pkt->pos          = pos;
-    pkt->size         = size;
-    pkt->flags       |= AV_PKT_FLAG_KEY;
-    pkt->stream_index = c->vst->index;
-    pkt->pts          = c->frames;
+    /* return the video packet, if the caller wants it */
+    if (pkt) {
+        size = dv_extract_video_info(c, buf);
+
+        pkt->data         = buf;
+        pkt->pos          = pos;
+        pkt->size         = size;
+        pkt->flags       |= AV_PKT_FLAG_KEY;
+        pkt->stream_index = c->vst->index;
+        pkt->pts          = c->frames;
+    }
 
     c->frames++;