diff --git a/README.md b/README.md
index ebc837843a..c5de1bc90b 100644
--- a/README.md
+++ b/README.md
@@ -361,3 +361,13 @@ packager \
   --hls_master_playlist_output="master_playlist.m3u8" \
   --hls_base_url="http://localhost:10000/"
 ```
+
+Create DASH trick play, a.k.a. trick mode, stream. The `trick_play_factor` in
+the stream descriptor specifies the sampling rate among the key frames in the
+video. For example, 1 means every key frame and 2 means every other key frame.
+```Shell
+packager \
+  'input=bear-1280x720.mp4,stream=video,output=bear-1280x720_video.mp4' \
+  'input=bear-1280x720.mp4,stream=video,output=bear-1280x720_video_trick_play.mp4,trick_play_factor=1' \
+  --mpd_output bear_trick_play.mpd
+```
diff --git a/packager/app/packager_main.cc b/packager/app/packager_main.cc
index 6508ec76de..2c19ef8f53 100644
--- a/packager/app/packager_main.cc
+++ b/packager/app/packager_main.cc
@@ -100,6 +100,9 @@ const char kUsage[] =
     "  - output_format (format): Optional value which specifies the format\n"
     "    of the output files (MP4 or WebM).  If not specified, it will be\n"
     "    derived from the file extension of the output file.\n"
+    "  - trick_play_factor (tpf): Optional value which specifies the trick\n"
+    "    play, a.k.a. trick mode, stream sampling rate among key frames.\n"
+    "    If specified, the output is a trick play stream.\n"
     "  - hls_name: Required for audio when outputting HLS.\n"
     "    name of the output stream. This is not (necessarily) the same as\n"
     "    output. This is used as the NAME attribute for EXT-X-MEDIA\n"