Em Sat, 4 Jul 2009 21:58:31 +0200 Erik Andrén <erik.andren@xxxxxxxxx> escreveu: > 08/24: gspca - m5602-ov7660: Create blue gain control > http://linuxtv.org/hg/~eandren/v4l-dvb?cmd=changeset;node=5675978999c5 > > 09/24: gspca - m5602-ov7660: Add red gain control > http://linuxtv.org/hg/~eandren/v4l-dvb?cmd=changeset;node=802e9a025e93 +#define RED_BALANCE_IDX 3 + { + { + .id = V4L2_CID_RED_BALANCE, + .type = V4L2_CTRL_TYPE_INTEGER, + .name = "red balance", + .minimum = 0x00, + .maximum = 0x7f, + .step = 0x1, + .default_value = OV7660_DEFAULT_RED_GAIN, + .flags = V4L2_CTRL_FLAG_SLIDER + }, + .set = ov7660_set_red_gain, + .get = ov7660_get_red_gain + }, }; x Hmm... as far as I understand, "Red Balance" and "Red gain" are different ways to see the same measure. Unfortunately, the V4L2 API is not clear about those controls. According with the spec, we have: V4L2_CID_CONTRAST integer Picture contrast or luma gain. V4L2_CID_SATURATION integer Picture color saturation or chroma gain. V4L2_CID_HUE integer Hue or color balance. V4L2_CID_RED_BALANCE integer Red chroma balance. V4L2_CID_BLUE_BALANCE integer Blue chroma balance. V4L2_CID_GAIN integer Gain control. >From what I'm understanding from the term "balance", it should be a shift over the gain control (so, 0 means normal colors, like on HUE balance). So, in order to convert from a RED GAIN into a RED BALANCE, we need to calculate it as a function of the V4L2_CID_GAIN or V4L2_CID_SATURATION. Positive values should mean more gain than the other colors, while negative values would mean the opposite. Since there are other patches that touch on it, I'll stop analyzing your series on those two patches. Cheers, Mauro -- 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
