Add dpx encoding regression test.

Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>

tests/lavf-regression.sh

@@ -179,6 +179,10 @@ if [ -n "$do_xwd" ] ; then
 do_image_formats xwd
 fi
 
+if [ -n "$do_dpx" ] ; then
+do_image_formats dpx
+fi
+
 # audio only
 
 if [ -n "$do_wav" ] ; then

tests/ref/lavf/dpx

@@ -0,0 +1,3 @@
+5bb43eae2d80da95d26f7fe4669d6166 *./tests/data/images/dpx/02.dpx
+./tests/data/images/dpx/%02d.dpx CRC=0x6da01946
+305792 ./tests/data/images/dpx/02.dpx