avformat/movenc: respect color_range when encoding dnxhd.

Set the ACLR atom appropriately for legal / full range.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/movenc.c

@@ -807,7 +807,11 @@ static int mov_write_avid_tag(AVIOContext *pb, MOVTrack *track)
     ffio_wfourcc(pb, "ACLR");
     ffio_wfourcc(pb, "ACLR");
     ffio_wfourcc(pb, "0001");
-    avio_wb32(pb, 2); /* yuv range: full 1 / normal 2 */
+    if (track->enc->color_range == AVCOL_RANGE_MPEG) { /* Legal range (16-235) */
+        avio_wb32(pb, 1); /* Corresponds to 709 in official encoder */
+    } else { /* Full range (0-255) */
+        avio_wb32(pb, 2); /* Corresponds to RGB in official encoder */
+    }
     avio_wb32(pb, 0); /* unknown */
 
     avio_wb32(pb, 24); /* size */