[libcamera-devel] [PATCH v3 3/3] cam: Add optional argument to --capture to specify how many frames to capture

[Umang Jain]

Hi Niklas,

Thanks for extending --capture to capture a certain no. of frames.
It super handy to use.

Just want to let you know, it does not work if I use short-hand "-C=10".
However, cam -c 1 --capture=10 seems to work just fine.

On $cam -c 1 -C=10 O get the following:

[uajain at localhost libcamera]$ sudo ./build/src/cam/cam  -c 1 -C=10
Can't parse integer argument for option --capture
Options:
...

On 7/25/20 12:48 AM, Niklas Söderlund wrote:
> Extend the '--capture' option with and optional numerical argument to be
> able to specify how many frames to capture before exiting. If the
> optional argument is not provided the old behavior of running until the
> user interrupts with a SIGINT is retained.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> * Changes since v2
> - Move check in Capture::requestComplete() as to not leak the created
>    but never used Request.
> * Changes since v1
> - Extend --capture option instead of adding a new --count option.
> ---
>   src/cam/capture.cpp | 18 ++++++++++++++++--
>   src/cam/capture.h   |  2 ++
>   src/cam/main.cpp    |  5 +++--
>   3 files changed, 21 insertions(+), 4 deletions(-)
>
> diff --git a/src/cam/capture.cpp b/src/cam/capture.cpp
> index f811a18c579508a1..3d8e89d52c7ab68d 100644
> --- a/src/cam/capture.cpp
> +++ b/src/cam/capture.cpp
> @@ -18,7 +18,8 @@ using namespace libcamera;
>   
>   Capture::Capture(std::shared_ptr<Camera> camera, CameraConfiguration *config,
>   		 EventLoop *loop)
> -	: camera_(camera), config_(config), writer_(nullptr), loop_(loop)
> +	: camera_(camera), config_(config), writer_(nullptr), loop_(loop),
> +	  captureCount_(0), captureLimit_(0)
>   {
>   }
>   
> @@ -26,6 +27,9 @@ int Capture::run(const OptionsParser::Options &options)
>   {
>   	int ret;
>   
> +	captureCount_ = 0;
> +	captureLimit_ = options[OptCapture].toInteger();
> +
>   	if (!camera_) {
>   		std::cout << "Can't capture without a camera" << std::endl;
>   		return -ENODEV;
> @@ -132,7 +136,11 @@ int Capture::capture(FrameBufferAllocator *allocator)
>   		}
>   	}
>   
> -	std::cout << "Capture until user interrupts by SIGINT" << std::endl;
> +	if (captureLimit_)
> +		std::cout << "Capture " << captureLimit_ << " frames" << std::endl;
> +	else
> +		std::cout << "Capture until user interrupts by SIGINT" << std::endl;
> +
>   	ret = loop_->exec();
>   	if (ret)
>   		std::cout << "Failed to run capture loop" << std::endl;
> @@ -184,6 +192,12 @@ void Capture::requestComplete(Request *request)
>   
>   	std::cout << info.str() << std::endl;
>   
> +	captureCount_++;
> +	if (captureLimit_ && captureCount_ >= captureLimit_) {
> +		loop_->exit(0);
> +		return;
> +	}
> +
>   	/*
>   	 * Create a new request and populate it with one buffer for each
>   	 * stream.
> diff --git a/src/cam/capture.h b/src/cam/capture.h
> index acdefc47b24314d2..32940a2a12138887 100644
> --- a/src/cam/capture.h
> +++ b/src/cam/capture.h
> @@ -41,6 +41,8 @@ private:
>   	std::chrono::steady_clock::time_point last_;
>   
>   	EventLoop *loop_;
> +	unsigned int captureCount_;
> +	unsigned int captureLimit_;
>   };
>   
>   #endif /* __CAM_CAPTURE_H__ */
> diff --git a/src/cam/main.cpp b/src/cam/main.cpp
> index 3e83feabe64e036c..f5aba041d7c4c181 100644
> --- a/src/cam/main.cpp
> +++ b/src/cam/main.cpp
> @@ -167,8 +167,9 @@ int CamApp::parseOptions(int argc, char *argv[])
>   	parser.addOption(OptCamera, OptionString,
>   			 "Specify which camera to operate on, by name or by index", "camera",
>   			 ArgumentRequired, "camera");
> -	parser.addOption(OptCapture, OptionNone,
> -			 "Capture until interrupted by user", "capture");
> +	parser.addOption(OptCapture, OptionInteger,
> +			 "Capture until interrupted by user or until <count> frames captured",
> +			 "capture", ArgumentOptional, "count");
>   	parser.addOption(OptFile, OptionString,
>   			 "Write captured frames to disk\n"
>   			 "The first '#' character in the file name is expanded to the stream name and frame sequence number.\n"