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Commit 54f577b7 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
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V4L/DVB (4193): Update cx2341x fw encoding API doc. 



Based on recent tests it turned out that some features are not implemented.
This has now been documented.

Signed-off-by: default avatarHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@infradead.org>
parent 18318e00

Documentation/video4linux/cx2341x/fw-encoder-api.txt

+18 −2
Original line number Diff line number Diff line
@@ -100,13 +100,20 @@ Param[1] 
Name 	CX2341X_ENC_SET_BIT_RATE

Enum 	149/0x95

Description

	Assign average video stream bitrate.

	Assign average video stream bitrate. Note on the last three params:

	Param[3] and [4] seem to be always 0, param [5] doesn't seem to be used.

Param[0]

	0=variable bitrate, 1=constant bitrate

Param[1]

	bitrate in bits per second

Param[2]

	peak bitrate in bits per second, divided by 400

Param[3]

	Mux bitrate in bits per second, divided by 400. May be 0 (default).

Param[4]

	Rate Control VBR Padding

Param[5]

	VBV Buffer used by encoder



-------------------------------------------------------------------------------
@@ -115,10 +122,11 @@ Enum 151/0x97 
Description

	Setup the GOP structure

Param[0]

	GOP size

	GOP size (maximum is 34)

Param[1]

	Number of B frames between the I and P frame, plus 1.

	For example: IBBPBBPBBPBB --> GOP size: 12, number of B frames: 2+1 = 3

	Note that GOP size must be a multiple of (B-frames + 1).



-------------------------------------------------------------------------------
@@ -241,6 +249,9 @@ Name CX2341X_ENC_SET_STREAM_TYPE 
Enum 	185/0xB9

Description

	Assign stream type

	Note: Transport stream is not working in recent firmwares.

	And in older firmwares the timestamps in the TS seem to be

	unreliable.

Param[0]

	 0=Program stream

	 1=Transport stream
@@ -278,6 +289,8 @@ Description 
		'01' Layer III

		'00' Undefined

	This discrepancy may indicate a possible error in the documentation.

	Testing indicated that only Layer II is actually working, and that

	the minimum bitrate should be 192 kbps.

Param[0]

	Bitmask:

	   0:1  '00' 44.1Khz
@@ -313,6 +326,9 @@ Param[0] 
		'01'=JointStereo

		'10'=Dual

		'11'=Mono

		Note: testing seems to indicate that Mono and possibly

		JointStereo are not working (default to stereo).

		Dual does work, though.



	  10:11 Mode Extension used in joint_stereo mode.

		In Layer I and II they indicate which subbands are in