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| author | Hans Verkuil <hverkuil@xs4all.nl> | 2006-06-18 19:56:12 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2006-06-25 07:05:22 +0200 |
| commit | 54f577b7f46f48b8bea0bd5eb8c42d711b3e006f (patch) | |
| tree | c091a214f10db8466feac1901ae3612fbbfd17c3 /Documentation/video4linux/cx2341x | |
| parent | V4L/DVB (4192): Use control helpers for saa7115, cx25840, msp3400. (diff) | |
| download | linux-54f577b7f46f48b8bea0bd5eb8c42d711b3e006f.tar.xz linux-54f577b7f46f48b8bea0bd5eb8c42d711b3e006f.zip | |
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: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'Documentation/video4linux/cx2341x')
| -rw-r--r-- | Documentation/video4linux/cx2341x/fw-encoder-api.txt | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/Documentation/video4linux/cx2341x/fw-encoder-api.txt b/Documentation/video4linux/cx2341x/fw-encoder-api.txt index 08ee9f5303f9..f74b0ae4a769 100644 --- a/Documentation/video4linux/cx2341x/fw-encoder-api.txt +++ b/Documentation/video4linux/cx2341x/fw-encoder-api.txt @@ -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 |