1 files changed, 14 insertions, 0 deletions

diff --git a/Documentation/video4linux/cx2341x/fw-decoder-api.txt b/Documentation/video4linux/cx2341x/fw-decoder-api.txt
index 78bf5f21e513..15c388b8bd19 100644
--- a/Documentation/video4linux/cx2341x/fw-decoder-api.txt
+++ b/Documentation/video4linux/cx2341x/fw-decoder-api.txt
@@ -32,6 +32,10 @@ Description
         playback stops at specified PTS.
 Param[0]
         Display 0=last frame, 1=black
+        Note: this takes effect immediately, so if you want to wait for a PTS,
+        then use '0', otherwise the screen goes to black at once.
+        You can call this later (even if there is no playback) with a 1 value
+        to set the screen to black.
 Param[1]
         PTS low
 Param[2]
@@ -60,8 +64,12 @@ Param[0]
             31   Speed:
                      '0' slow
                      '1' fast
+        Note: n seems to be limited to 2. Anything higher does not result in
+        faster playback. Instead the host should start dropping frames.
 Param[1]
         Direction: 0=forward, 1=reverse
+        Note: to make reverse playback work you have to write full GOPs in
+        reverse order.
 Param[2]
         Picture mask:
             1=I frames
@@ -69,6 +77,8 @@ Param[2]
             7=I, P, B frames
 Param[3]
         B frames per GOP (for reverse play only)
+        Note: apparently this does not work. For reverse play I can only make it
+        work by selecting I or I and P frames in the Picture mask.
 Param[4]
         Mute audio: 0=disable, 1=enable
 Param[5]
@@ -212,6 +222,7 @@ Description
         Select audio mode
 Param[0]
         Dual mono mode action
+            0=Stereo, 1=Left, 2=Right, 3=Mono, 4=Swap, -1=Unchanged
 Param[1]
         Stereo mode action:
             0=Stereo, 1=Left, 2=Right, 3=Mono, 4=Swap, -1=Unchanged
@@ -225,6 +236,9 @@ Description
         Counterpart to API 0xD5
 Param[0]
         Event: 0=Audio mode change between stereo and dual channel
+        Event: 3=Decoder started
+        Event: 4=Unknown: goes off 10-15 times per second while decoding.
+        Event: 5=Some sync event: goes off once per frame.
 Param[1]
         Notification 0=disabled, 1=enabled
 Param[2]