[libcamera-devel] [PATCH v6 2/6] libcamera: ipu3: Use roles in stream configuration

[Laurent Pinchart]

Hi Jacopo,

Thank you for the patch.

On Thu, Apr 18, 2019 at 06:46:34PM +0200, Jacopo Mondi wrote:
> Use and inspect the stream roles provided by the application to
> streamConfiguration() to assign streams to their intended roles and
> return a default configuration associated with them.
> 
> Support a limited number of usages, as the viewfinder stream can
> optionally be used for capturing still images, but the main output
> stream cannot be used as viewfinder or for video recording purposes.

This is an artificial limitation, isn't it ? I'd like that to be
recorded in the commit message. Maybe

Support a limited number of usages, with the viewfinder stream able to
capture both continuous video streams and still images, and the main
output stream supporting still images images. This is an artificial
limitation until we figure out the exact capabilities of the hardware.

> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
>  src/libcamera/pipeline/ipu3/ipu3.cpp | 99 +++++++++++++++++++---------
>  1 file changed, 69 insertions(+), 30 deletions(-)
> 
> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> index b9eb872fd5b2..8c2504499f33 100644
> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> @@ -221,38 +221,77 @@ CameraConfiguration
>  PipelineHandlerIPU3::streamConfiguration(Camera *camera,
>  					 const std::vector<StreamUsage> &usages)
>  {
> -	CameraConfiguration configs;
>  	IPU3CameraData *data = cameraData(camera);
> -	StreamConfiguration config = {};
> +	CameraConfiguration cameraConfig;
> +	std::set<IPU3Stream *> streams = {
> +		&data->outStream_,
> +		&data->vfStream_,
> +	};
>  
> -	/*
> -	 * FIXME: Soraka: the maximum resolution reported by both sensors
> -	 * (2592x1944 for ov5670 and 4224x3136 for ov13858) are returned as
> -	 * default configurations but they're not correctly processed by the
> -	 * ImgU. Resolutions up tp 2560x1920 have been validated.
> -	 *
> -	 * \todo Clarify ImgU alignement requirements.
> -	 */
> -	config.width = 2560;
> -	config.height = 1920;
> -	config.pixelFormat = V4L2_PIX_FMT_NV12;
> -	config.bufferCount = IPU3_BUFFER_COUNT;
> -
> -	configs[&data->outStream_] = config;
> -	LOG(IPU3, Debug)
> -		<< "Stream '" << data->outStream_.name_ << "' set to "
> -		<< config.width << "x" << config.height << "-0x"
> -		<< std::hex << std::setfill('0') << std::setw(8)
> -		<< config.pixelFormat;
> -
> -	configs[&data->vfStream_] = config;
> -	LOG(IPU3, Debug)
> -		<< "Stream '" << data->vfStream_.name_ << "' set to "
> -		<< config.width << "x" << config.height << "-0x"
> -		<< std::hex << std::setfill('0') << std::setw(8)
> -		<< config.pixelFormat;
> -
> -	return configs;
> +	for (const StreamUsage &usage : usages) {
> +		std::vector<IPU3Stream *>::iterator found;
> +		StreamUsage::Role role = usage.role();
> +		StreamConfiguration streamConfig = {};
> +		IPU3Stream *stream = nullptr;
> +
> +		if (role == StreamUsage::Role::StillCapture) {
> +			/*
> +			 * We can use the viewfinder stream in case the
> +			 * 'StillCapture' usage is required multiple times.
> +			 */
> +			if (streams.find(&data->outStream_) != streams.end())
> +				stream = &data->outStream_;
> +			else if (streams.find(&data->vfStream_) != streams.end())
> +				stream = &data->vfStream_;
> +			else
> +				goto error;
> +
> +			/*
> +			 * FIXME: Soraka: the maximum resolution reported by
> +			 * both sensors (2592x1944 for ov5670 and 4224x3136 for
> +			 * ov13858) are returned as default configurations but
> +			 * they're not correctly processed by the ImgU.
> +			 * Resolutions up tp 2560x1920 have been validated.
> +			 *
> +			 * \todo Clarify ImgU alignment requirements.
> +			 */
> +			streamConfig.width = 2560;
> +			streamConfig.height = 1920;
> +		} else if (role == StreamUsage::Role::Viewfinder ||
> +			   role == StreamUsage::Role::VideoRecording) {
> +			/*
> +			 * We can't use the 'output' stream for viewfinder or
> +			 * video capture usages.

And here, "Don't allow viewfinder or video capture on the 'output'
stream. This is an artificial limitation until we figure out the
capabilities of the hardware."

> +			 */
> +			if (streams.find(&data->vfStream_) == streams.end())
> +				goto error;
> +
> +			stream = &data->vfStream_;
> +
> +			streamConfig.width = usage.size().width;
> +			streamConfig.height = usage.size().height;

Should this be rounded to the alignment requirements of the ImgU, and
clamped to the minimum - maximum achievable sizes ?

> +		}

You will crash if none of those roles match. Let's use a switch() ...
case and return an error in the default case.

> +
> +		streams.erase(stream);
> +
> +		streamConfig.pixelFormat = V4L2_PIX_FMT_NV12;
> +		streamConfig.bufferCount = IPU3_BUFFER_COUNT;
> +
> +		cameraConfig[stream] = streamConfig;
> +
> +		LOG(IPU3, Debug)
> +			<< "Stream '" << stream->name_ << "' format set to "
> +			<< streamConfig.width << "x" << streamConfig.height
> +			<< "-0x" << std::hex << std::setfill('0')
> +			<< std::setw(8) << streamConfig.pixelFormat;

Here too you can use streamConfig.toString() if my patches get merged
first. Otherwise I'll rebase them.

> +	}
> +
> +	return cameraConfig;
> +
> +error:
> +	LOG(IPU3, Error) << "Requested stream roles not supported";
> +
> +	return CameraConfiguration{};
>  }
>  
>  int PipelineHandlerIPU3::configureStreams(Camera *camera,

-- 
Regards,

Laurent Pinchart