[libcamera-devel] [PATCH v2] ipa: ipu3: Replace ipa::ipu3::algorithms::Ipu3AwbCell
Kieran Bingham
kieran.bingham at ideasonboard.com
Fri Sep 3 15:44:14 CEST 2021
On 02/09/2021 17:06, Jean-Michel Hautbois wrote:
> The intel-ipu3.h public interface from the kernel does not define how to
> parse the statistics for a cell. This had to be identified by a process
> of reverse engineering, and later identifying the structures from
> https://chromium.googlesource.com/chromiumos/platform/arc-camera/+/refs/heads/master/hal/intel/include/ia_imaging/awb_public.h
> leading to our custom definition of struct Ipu3AwbCell.
>
> To improve the kernel interface, a proposal has been made to the
> linux-kernel [0] to incorporate the memory layout for each cell into the
> intel-ipu3 header directly.
>
> [0]
> https://lore.kernel.org/linux-media/20210831185140.77400-1-jeanmichel.hautbois@ideasonboard.com/
>
> Update our local copy of the intel-ipu3.h to match the proposal and
> change the AGC and AWB algorithms to reference that structure directly,
> allowing us to remove the deprecated custom Ipu3AwbCell definition.
>
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>
> ---
> include/linux/intel-ipu3.h | 38 +++++++++++++++++++++++++--------
> src/ipa/ipu3/algorithms/agc.cpp | 7 +++---
> src/ipa/ipu3/algorithms/awb.cpp | 10 ++++-----
> src/ipa/ipu3/algorithms/awb.h | 10 ---------
> 4 files changed, 38 insertions(+), 27 deletions(-)
>
> diff --git a/include/linux/intel-ipu3.h b/include/linux/intel-ipu3.h
> index ee0e6d0e..0633e04e 100644
> --- a/include/linux/intel-ipu3.h
> +++ b/include/linux/intel-ipu3.h
> @@ -59,20 +59,40 @@ struct ipu3_uapi_grid_config {
> __u16 y_end;
> } __attribute__((packed));
>
> +/**
> + * struct ipu3_uapi_awb_set_item - Memory layout for each cell in AWB
> + *
> + * @Gr_avg: Green average for red lines in the cell.
> + * @R_avg: Red average in the cell.
> + * @B_avg: Blue average in the cell.
> + * @Gb_avg: Green average for blue lines in the cell.
> + * @sat_ratio: Saturation ratio in the cell.
> + * @padding0: Unused byte for padding.
> + * @padding1: Unused byte for padding.
> + * @padding2: Unused byte for padding.
> + */
> +struct ipu3_uapi_awb_set_item {
> + unsigned char Gr_avg;
> + unsigned char R_avg;
> + unsigned char B_avg;
> + unsigned char Gb_avg;
> + unsigned char sat_ratio;
> + unsigned char padding0;
> + unsigned char padding1;
> + unsigned char padding2;
> +} __attribute__((packed));
> +
> /*
> * The grid based data is divided into "slices" called set, each slice of setX
> * refers to ipu3_uapi_grid_config width * height_per_slice.
> */
> #define IPU3_UAPI_AWB_MAX_SETS 60
> -/* Based on grid size 80 * 60 and cell size 16 x 16 */
> -#define IPU3_UAPI_AWB_SET_SIZE 1280
> -#define IPU3_UAPI_AWB_MD_ITEM_SIZE 8
> -#define IPU3_UAPI_AWB_SPARE_FOR_BUBBLES \
> - (IPU3_UAPI_MAX_BUBBLE_SIZE * IPU3_UAPI_MAX_STRIPES * \
> - IPU3_UAPI_AWB_MD_ITEM_SIZE)
> +#define AWB_PUBLIC_NUM_OF_ITEMS_IN_SET 160
> +/* Based on max grid height + Spare for bubbles */
> +#define AWB_PUBLIC_NUM_OF_SETS_IN_BUFFER IPU3_UAPI_AWB_MAX_SETS + \
> + (IPU3_UAPI_MAX_BUBBLE_SIZE * IPU3_UAPI_MAX_STRIPES)
> #define IPU3_UAPI_AWB_MAX_BUFFER_SIZE \
> - (IPU3_UAPI_AWB_MAX_SETS * \
> - (IPU3_UAPI_AWB_SET_SIZE + IPU3_UAPI_AWB_SPARE_FOR_BUBBLES))
> + AWB_PUBLIC_NUM_OF_SETS_IN_BUFFER * AWB_PUBLIC_NUM_OF_ITEMS_IN_SET
>
>
> /**
> @@ -82,7 +102,7 @@ struct ipu3_uapi_grid_config {
> * the average values for each color channel.
> */
> struct ipu3_uapi_awb_raw_buffer {
> - __u8 meta_data[IPU3_UAPI_AWB_MAX_BUFFER_SIZE]
> + struct ipu3_uapi_awb_set_item meta_data[IPU3_UAPI_AWB_MAX_BUFFER_SIZE]
> __attribute__((aligned(32)));
> } __attribute__((packed));
I'll somewhat ignore all those changes, as they will be reviewed on
linux-media.
As long as we track any changes that occur in the upstreaming process
here, it's fine.
>
> diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp
> index 5ff50f4a..36f648be 100644
> --- a/src/ipa/ipu3/algorithms/agc.cpp
> +++ b/src/ipa/ipu3/algorithms/agc.cpp
> @@ -96,9 +96,10 @@ void Agc::processBrightness(const ipu3_uapi_stats_3a *stats,
> * We observed a bit shift which makes the value 160 to be 32 in the stats grid.
> * Use the one passed at init time.
> */
> - if (stats->awb_raw_buffer.meta_data[i + 4 + j * grid.width] == 0) {
> - uint8_t Gr = stats->awb_raw_buffer.meta_data[i + 0 + j * grid.width];
> - uint8_t Gb = stats->awb_raw_buffer.meta_data[i + 3 + j * grid.width];
> + const ipu3_uapi_awb_set_item *currentCell = &stats->awb_raw_buffer.meta_data[i + 4 + j * grid.width];
stats->awb_raw_buffer.meta_data has gone from an array of u8, where you
index it by
"i + 4 + j * grid.width"
to an array of struct ipu3_uapi_awb_set_item yet it's still indexed here by
"i + 4 + j * grid.width"
That doesn't sound right to me.. It will be reading different offsets
than before... Does it work ?
> + if (currentCell->sat_ratio == 0) {
> + uint8_t Gr = currentCell->Gr_avg;
> + uint8_t Gb = currentCell->Gb_avg;
Otherwise, that looks cleaner and more readable though ;-)
> hist[(Gr + Gb) / 2]++;
> count++;
> }
> diff --git a/src/ipa/ipu3/algorithms/awb.cpp b/src/ipa/ipu3/algorithms/awb.cpp
> index 06b66bbb..7c0b7639 100644
> --- a/src/ipa/ipu3/algorithms/awb.cpp
> +++ b/src/ipa/ipu3/algorithms/awb.cpp
> @@ -207,14 +207,14 @@ void Awb::generateAwbStats(const ipu3_uapi_stats_3a *stats,
> cellPosition *= 8;
>
> /* Cast the initial IPU3 structure to simplify the reading */
> - Ipu3AwbCell *currentCell = reinterpret_cast<Ipu3AwbCell *>(const_cast<uint8_t *>(&stats->awb_raw_buffer.meta_data[cellPosition]));
> - if (currentCell->satRatio == 0) {
> + const ipu3_uapi_awb_set_item *currentCell = &stats->awb_raw_buffer.meta_data[cellPosition];
And again here - I presume cellPosition would need to change given the
change in type of meta_data...
> + if (currentCell->sat_ratio == 0) {
> /* The cell is not saturated, use the current cell */
> awbStats_[awbRegionPosition].counted++;
> - uint32_t greenValue = currentCell->greenRedAvg + currentCell->greenBlueAvg;
> + uint32_t greenValue = currentCell->Gr_avg + currentCell->Gb_avg;
> awbStats_[awbRegionPosition].sum.green += greenValue / 2;
> - awbStats_[awbRegionPosition].sum.red += currentCell->redAvg;
> - awbStats_[awbRegionPosition].sum.blue += currentCell->blueAvg;
> + awbStats_[awbRegionPosition].sum.red += currentCell->R_avg;
> + awbStats_[awbRegionPosition].sum.blue += currentCell->B_avg;
> }
> }
> }
> diff --git a/src/ipa/ipu3/algorithms/awb.h b/src/ipa/ipu3/algorithms/awb.h
> index 23f3e872..a9320b4c 100644
> --- a/src/ipa/ipu3/algorithms/awb.h
> +++ b/src/ipa/ipu3/algorithms/awb.h
> @@ -23,16 +23,6 @@ namespace ipa::ipu3::algorithms {
> static constexpr uint32_t kAwbStatsSizeX = 16;
> static constexpr uint32_t kAwbStatsSizeY = 12;
>
> -/* \todo Move the cell layout into intel-ipu3.h kernel header */
> -struct Ipu3AwbCell {
> - unsigned char greenRedAvg;
> - unsigned char redAvg;
> - unsigned char blueAvg;
> - unsigned char greenBlueAvg;
> - unsigned char satRatio;
> - unsigned char padding[3];
> -} __attribute__((packed));
> -
> struct Accumulator {
> unsigned int counted;
> unsigned int total;
>
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