On 09/21/2011 03:24 PM, Sylwester Nawrocki wrote: > Hi Laurent, > > On 09/21/2011 01:12 AM, Laurent Pinchart wrote: >> Hi Sylwester, >> >> Thanks for the patch. >> >> On Monday 19 September 2011 19:07:55 Sylwester Nawrocki wrote: >>> FIELD is an Even/Odd field selection signal, as specified in ITU-R BT.601 >>> standard. Add corresponding flag for configuring the FIELD signal polarity. >>> Also add a comment about usage of V4L2_MBUS_[HV]SYNC* flags for the >>> hardware that uses [HV]REF signals. >> >> I like this approach better. >> > ... >>> +/* Field selection signal for interlaced scan mode */ >>> +#define V4L2_MBUS_FIELD_ACTIVE_HIGH (1 << 10) >>> +#define V4L2_MBUS_FIELD_ACTIVE_LOW (1 << 11) >> >> What does this mean ? The FIELD signal is used to select between odd and even >> fields. Does "active high" mean that the field is odd or even when the signal >> has a high level ? The comment should make it explicit, or we could even >> rename those two constants to FIELD_ODD_HIGH/FIELD_ODD_LOW (or >> FIELD_EVEN_HIGH/FIELD_EVEN_LOW). > > Yes, certainly I didn't think enough about this. I silently assumed that for > V4L2_MBUS_FIELD_ACTIVE_HIGH FIELD = 0 selects Field1 (odd) and FIELD = 1 selects > Field2 (even). > I think it would be good to construct the macro so it is possibly self-explanatory, > rather than requiring often to dig in the documentation. > > So I would go for V4L2_MBUS_FIELD_ODD_LOW/V4L2_MBUS_FIELD_ODD_HIGH. > Unless someone proposes something different/better I'll send an amended version > tomorrow. Thinking some more of it, V4L2_MBUS_FIELD_EVEN_HIGH/V4L2_MBUS_FIELD_EVEN_LOW is perhaps more in line with other defines where *HIGH means standard, non-inverted case. So it seems better to me. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
