Uhm, +Laurent. Sorry for the noise.
On Tue, Jun 6, 2017 at 1:30 PM, Tomasz Figa <tfiga@xxxxxxxxxxxx> wrote:
> Hi Yong,
>
> On Tue, Jun 6, 2017 at 5:39 AM, Yong Zhi <yong.zhi@xxxxxxxxx> wrote:
>> Add the IPU3 specific processing parameter format
>> V4L2_META_FMT_IPU3_PARAMS and metadata formats
>> for 3A and other statistics:
>
> Please see my comments inline.
>
>>
>> V4L2_META_FMT_IPU3_PARAMS
>> V4L2_META_FMT_IPU3_STAT_3A
>> V4L2_META_FMT_IPU3_STAT_DVS
>> V4L2_META_FMT_IPU3_STAT_LACE
>>
>> Signed-off-by: Yong Zhi <yong.zhi@xxxxxxxxx>
>> ---
>> drivers/media/v4l2-core/v4l2-ioctl.c | 4 ++++
>> include/uapi/linux/videodev2.h | 6 ++++++
>> 2 files changed, 10 insertions(+)
> [snip]
>> +/* Vendor specific - used for IPU3 camera sub-system */
>> +#define V4L2_META_FMT_IPU3_PARAMS v4l2_fourcc('i', 'p', '3', 'p') /* IPU3 params */
>> +#define V4L2_META_FMT_IPU3_STAT_3A v4l2_fourcc('i', 'p', '3', 's') /* IPU3 3A statistics */
>> +#define V4L2_META_FMT_IPU3_STAT_DVS v4l2_fourcc('i', 'p', '3', 'd') /* IPU3 DVS statistics */
>> +#define V4L2_META_FMT_IPU3_STAT_LACE v4l2_fourcc('i', 'p', '3', 'l') /* IPU3 LACE statistics */
>
> We had some discussion about this with Laurent and if I remember
> correctly, the conclusion was that it might make sense to define one
> FourCC for a vendor specific format, ('v', 'n', 'd', 'r') for example,
> and then have a V4L2-specific enum within the v4l2_pix_format(_mplane)
> struct that specifies the exact vendor data type. It seems saner than
> assigning a new FourCC whenever a new hardware revision comes out,
> especially given that FourCCs tend to be used outside of the V4L2
> world as well and being kind of (de facto) standardized (with existing
> exceptions, unfortunately).
>
> Best regards,
> Tomasz
