Hi, The current definition of the VIDIOC_S_FMT for the VBI makes a restriction that, requiring the calling application to define a RANGE of lines. It also does not specify how the API for sliced data should look. Also, it is possible to have multiple formats in different lines. The driver should be able to simultaneously capture different formats. Here are some ideas to address these, 1. Each open should be configurable for a SET of lines and the format. For example, the user should be able to use one open instance to read Closed Caption data and use another open for say, WSS. 2. Rather than setting a range of lines in the VIDIOC_S_FMT, we should be able to request a SET of lines. This can be done without altering the current API by making the VIDIOC_S_FMT cumulative, i.e. the previously set range of lines is "remembered". A special format value can be defined to reset all the lines. All the lines for a particular format can be read by a single open instance. This would also make it easy to ensure that the lines are received by the user in broadcast order. 3. 2 Byte header for Sliced data. If we follow 2, it would be necessary to indicate to the reader, to which line of video data, the data in the buffer belongs to. We could have a two byte header before each line of data, to indicate the line number, the field and the validity of the data in that line. Comments, suggestions? Regards Sojan.
