[libcamera-devel] [PATCH v3 09/16] libcamera: simple: Report sensor timestamp

[Laurent Pinchart]

Hi Jacopo,

Thank you for the patch.

On Wed, Apr 21, 2021 at 06:03:12PM +0200, Jacopo Mondi wrote:
> Report the sensor's timestamp in the Request metadata using the
> completed buffer timestamp.
> 
> The buffer's timestamp is recorded at DMA-transfer time, and it does not
> theoretically matches the 'start of exposure' definition. Record this with
> a \todo entry.
> 
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
>  src/libcamera/pipeline/simple/simple.cpp | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
> index f6095d38e97a..e1ee640b0a92 100644
> --- a/src/libcamera/pipeline/simple/simple.cpp
> +++ b/src/libcamera/pipeline/simple/simple.cpp
> @@ -22,6 +22,7 @@
>  #include <linux/media-bus-format.h>
>  
>  #include <libcamera/camera.h>
> +#include <libcamera/control_ids.h>
>  #include <libcamera/request.h>
>  #include <libcamera/stream.h>
>  
> @@ -1116,6 +1117,16 @@ void SimplePipelineHandler::bufferReady(FrameBuffer *buffer)
>  		return;
>  	}
>  
> +	/*
> +	 * Record the sensor's timestamp in the request metadata.
> +	 *
> +	 * \todo The sensor timestamp should be better estimated by connecting
> +	 * to the V4L2Device::frameStart signal if the platform provides it.
> +	 */
> +	Request *request = buffer->request();
> +	request->metadata().set(controls::SensorTimestamp,
> +				buffer->metadata().timestamp);
> +
>  	/*
>  	 * Queue the captured and the request buffer to the converter if format
>  	 * conversion is needed. If there's no queued request, just requeue the
> @@ -1133,7 +1144,6 @@ void SimplePipelineHandler::bufferReady(FrameBuffer *buffer)
>  	}
>  
>  	/* Otherwise simply complete the request. */
> -	Request *request = buffer->request();
>  	completeBuffer(request, buffer);
>  	completeRequest(request);
>  }

-- 
Regards,

Laurent Pinchart