diff --git a/libavformat/isom.c b/libavformat/isom.c
index 901a8b3ff8..f6e81cdcfb 100644
--- a/libavformat/isom.c
+++ b/libavformat/isom.c
@@ -107,6 +107,8 @@ const AVCodecTag codec_movvideo_tags[] = {
     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '3') }, /* HDV produced by FCP */
     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '5', 'n') }, /* MPEG2 IMX NTSC 525/60 50mb/s produced by FCP */
     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '5', 'p') }, /* MPEG2 IMX PAL 625/50 50mb/s produced by FCP */
+    { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '4', 'n') }, /* MPEG2 IMX NTSC 525/60 40mb/s produced by FCP */
+    { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '4', 'p') }, /* MPEG2 IMX PAL 625/50 40mb/s produced by FCP */
     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '3', 'n') }, /* MPEG2 IMX NTSC 525/60 30mb/s produced by FCP */
     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '3', 'p') }, /* MPEG2 IMX PAL 625/50 30mb/s produced by FCP */
     { CODEC_ID_MPEG2VIDEO, MKTAG('x', 'd', 'v', '2') }, /* XDCAM HD 1080i60 */