V4L/DVB (4985): Update cx2341x documentation.
Removed a few unimplemented commands. Added a note for a few fields that are
not implemented in the firmware, and clarified several issues around reverse
playback.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/Documentation/video4linux/cx2341x/fw-decoder-api.txt b/Documentation/video4linux/cx2341x/fw-decoder-api.txt
index 15c388b..1345d26 100644
--- a/Documentation/video4linux/cx2341x/fw-decoder-api.txt
+++ b/Documentation/video4linux/cx2341x/fw-decoder-api.txt
@@ -21,7 +21,7 @@
0 based frame number in GOP to begin playback from.
Param[1]
Specifies the number of muted audio frames to play before normal
- audio resumes.
+ audio resumes. (This is not implemented in the firmware, leave at 0)
-------------------------------------------------------------------------------
@@ -64,7 +64,7 @@
31 Speed:
'0' slow
'1' fast
- Note: n seems to be limited to 2. Anything higher does not result in
+ Note: n is 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
@@ -77,15 +77,16 @@
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.
+ Note: for reverse playback the Picture Mask should be set to I or I, P.
+ Adding B frames to the mask will result in corrupt video. This field
+ has to be set to the correct value in order to keep the timing correct.
Param[4]
Mute audio: 0=disable, 1=enable
Param[5]
Display 0=frame, 1=field
Param[6]
Specifies the number of muted audio frames to play before normal audio
- resumes.
+ resumes. (Not implemented in the firmware, leave at 0)
-------------------------------------------------------------------------------
@@ -287,43 +288,6 @@
-------------------------------------------------------------------------------
-Name CX2341X_DEC_SET_AUDIO_OUTPUT
-Enum 27/0x1B
-Description
- Select audio output format
-Param[0]
- Bitmask:
- 0:1 Data size:
- '00' 16 bit
- '01' 20 bit
- '10' 24 bit
- 2:7 Unused
- 8:9 Mode:
- '00' 2 channels
- '01' 4 channels
- '10' 6 channels
- '11' 6 channels with one line data mode
- (for left justified MSB first mode, 20 bit only)
- 10:11 Unused
- 12:13 Channel format:
- '00' right justified MSB first mode
- '01' left justified MSB first mode
- '10' I2S mode
- 14:15 Unused
- 16:21 Right justify bit count
- 22:31 Unused
-
--------------------------------------------------------------------------------
-
-Name CX2341X_DEC_SET_AV_DELAY
-Enum 28/0x1C
-Description
- Set audio/video delay in 90Khz ticks
-Param[0]
- 0=A/V in sync, negative=audio lags, positive=video lags
-
--------------------------------------------------------------------------------
-
Name CX2341X_DEC_SET_PREBUFFERING
Enum 30/0x1E
Description