[libcamera-devel] [PATCH v3 13/16] libcamera: raspberry: Report sensor timestamp

[Hirokazu Honda]

Hi Jacopo, thank you for the patch.

On Thu, Apr 22, 2021 at 1:03 AM Jacopo Mondi <jacopo at jmondi.org> wrote:
>
> Report the sensor's timestamp in the Request metadata by using the
> Unicam::Image buffer timestamp as an initial approximation.
>
> The buffer's timestamp is recorded at DMA-transfer time, and it does not
> theoretically matches the 'start of exposure' definition, but when used
> to compare two consecutive frames it gives an acceptable estimation of
> the sensor frame period duration.
>
> Reviewed-by: Naushir Patuck <naush at raspberrypi.com>
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
>  src/libcamera/pipeline/raspberrypi/raspberrypi.cpp | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> index 6c6d31f78c88..ac135f95de12 100644
> --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> @@ -1414,6 +1414,18 @@ void RPiCameraData::unicamBufferDequeue(FrameBuffer *buffer)
>                         << ", timestamp: " << buffer->metadata().timestamp;
>
>         if (stream == &unicam_[Unicam::Image]) {
> +               /*
> +                * Record the sensor timestamp in the Request.
> +                *
> +                * \todo Do not assume the request in the front of the queue
> +                * is the correct one
> +                */

Can you have any idea how to get rid of this assumption?
I am ok with this patch as-is while the todo should be resolved in the
near future.

Reviewed-by: Hirokazu Honda <hiroh at chromium.org>

> +               Request *request = requestQueue_.front();
> +               ASSERT(request);
> +
> +               request->metadata().set(controls::SensorTimestamp,
> +                                       buffer->metadata().timestamp);
> +
>                 /*
>                  * Lookup the sensor controls used for this frame sequence from
>                  * DelayedControl and queue them along with the frame buffer.
> --
> 2.31.1
>
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