diff options
Diffstat (limited to 'linux/Documentation/video4linux/cx2341x/fw-encoder-api.txt')
| -rw-r--r-- | linux/Documentation/video4linux/cx2341x/fw-encoder-api.txt | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/linux/Documentation/video4linux/cx2341x/fw-encoder-api.txt b/linux/Documentation/video4linux/cx2341x/fw-encoder-api.txt index 08ee9f530..001c68644 100644 --- a/linux/Documentation/video4linux/cx2341x/fw-encoder-api.txt +++ b/linux/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 @@ -259,11 +270,17 @@ Param[0] Name CX2341X_ENC_SET_OUTPUT_PORT Enum 187/0xBB Description - Assign stream output port (not recommended you change setting from default) + Assign stream output port. Normally 0 when the data is copied through + the PCI bus (DMA), and 1 when the data is streamed to another chip + (pvrusb and cx88-blackbird). Param[0] 0=Memory (default) 1=Streaming 2=Serial +Param[1] + Unknown, but leaving this to 0 seems to work best. Indications are that + this might have to do with USB support, although passing anything but 0 + onl breaks things. ------------------------------------------------------------------------------- @@ -278,6 +295,8 @@ 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 +332,9 @@ 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 |