diff options
Diffstat (limited to 'drivers/media/video/cx18/cx18-av-core.h')
| -rw-r--r-- | drivers/media/video/cx18/cx18-av-core.h | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/drivers/media/video/cx18/cx18-av-core.h b/drivers/media/video/cx18/cx18-av-core.h index fd0df4151211..2687a2c91ddd 100644 --- a/drivers/media/video/cx18/cx18-av-core.h +++ b/drivers/media/video/cx18/cx18-av-core.h @@ -89,16 +89,21 @@ struct cx18_av_state { /* * The VBI slicer starts operating and counting lines, begining at - * slicer line count of 1, at D lines after the deassertion of VRESET - * This staring field line, S, is 6 or 10 for 625 or 525 line systems. - * Sliced ancillary data captured on VBI slicer line M is sent at the - * beginning of the next VBI slicer line, VBI slicer line count N = M+1. - * Thus when the VBI slicer reports a VBI slicer line number with - * ancillary data, the IDID0 byte indicates VBI slicer line N. - * The actual field line that the captured data comes from is + * slicer line count of 1, at D lines after the deassertion of VRESET. + * This staring field line, S, is 6 (& 319) or 10 (& 273) for 625 or 525 + * line systems respectively. Sliced ancillary data captured on VBI + * slicer line M is inserted after the VBI slicer is done with line M, + * when VBI slicer line count is N = M+1. Thus when the VBI slicer + * reports a VBI slicer line number with ancillary data, the IDID0 byte + * indicates VBI slicer line N. The actual field line that the captured + * data comes from is + * * L = M+(S+D-1) = N-1+(S+D-1) = N + (S+D-2). * + * L is the line in the field, not frame, from which the VBI data came. + * N is the line reported by the slicer in the ancillary data. * D is the slicer_line_delay value programmed into register 0x47f. + * S is 6 for 625 line systems or 10 for 525 line systems * (S+D-2) is the slicer_line_offset used to convert slicer reported * line counts to actual field lines. */ |