[libcamera-devel] [PATCH 14/20] libcamera: ipu3: Adjust and assign streams in validate()

[Jacopo Mondi]

Hi Laurent,

On Wed, Jul 15, 2020 at 01:06:52AM +0300, Laurent Pinchart wrote:
> Hi Jacopo,
>
> Thank you for the patch.
>
> On Tue, Jul 14, 2020 at 12:42:06PM +0200, Jacopo Mondi wrote:
> > Remove the adjustStream() and assignStream() methods, and perform stream
> > adjustment and assignment while iterating the StreamConfiguration
> > items.
> >
> > The adjustStream() implementation had some arbitrary assumption, like
> > the main output having to be as large as the sensor resolution, and did
> > not take into account the different alignment requirements between the
> > main output and the viewfinder output.
> >
> > The assignStream() implementation also assumes only full-size streams
> > can be produced by the main output, and having it as a separate function
> > prevents adjusting streams according to which output they are assigned.
> >
> > Blend the two implementation in a single loop and perform the required
> > stream adjustment and assignment in one go.
> >
> > As streams are now assigned at validate() time, remove the same
> > operation from the configure() function.
> >
> > Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> > ---
> >  src/libcamera/pipeline/ipu3/ipu3.cpp | 247 ++++++++++++---------------
> >  1 file changed, 108 insertions(+), 139 deletions(-)
> >
> > diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> > index 19e07fd57e39..1161987a4322 100644
> > --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> > +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> > @@ -70,9 +70,6 @@ public:
> >  	const std::vector<const Stream *> &streams() { return streams_; }
> >
> >  private:
> > -	void assignStreams();
> > -	void adjustStream(StreamConfiguration &cfg, bool scale);
> > -
> >  	/*
> >  	 * The IPU3CameraData instance is guaranteed to be valid as long as the
> >  	 * corresponding Camera instance is valid. In order to borrow a
> > @@ -137,96 +134,6 @@ IPU3CameraConfiguration::IPU3CameraConfiguration(Camera *camera,
> >  	data_ = data;
> >  }
> >
> > -void IPU3CameraConfiguration::assignStreams()
> > -{
> > -	/*
> > -	 * Verify and update all configuration entries, and assign a stream to
> > -	 * each of them. The viewfinder stream can scale, while the output
> > -	 * stream can crop only, so select the output stream when the requested
> > -	 * resolution is equal to the sensor resolution, and the viewfinder
> > -	 * stream otherwise.
> > -	 */
> > -	std::set<const Stream *> availableStreams = {
> > -		&data_->outStream_,
> > -		&data_->vfStream_,
> > -		&data_->rawStream_,
> > -	};
> > -
> > -	/*
> > -	 * The caller is responsible to limit the number of requested streams
> > -	 * to a number supported by the pipeline before calling this function.
> > -	 */
> > -	ASSERT(availableStreams.size() >= config_.size());
> > -
> > -	streams_.clear();
> > -	streams_.reserve(config_.size());
> > -
> > -	for (const StreamConfiguration &cfg : config_) {
> > -		const PixelFormatInfo &info =
> > -			PixelFormatInfo::info(cfg.pixelFormat);
> > -		const Stream *stream;
> > -
> > -		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW)
> > -			stream = &data_->rawStream_;
> > -		else if (cfg.size == cio2Configuration_.size)
> > -			stream = &data_->outStream_;
> > -		else
> > -			stream = &data_->vfStream_;
> > -
> > -		if (availableStreams.find(stream) == availableStreams.end())
> > -			stream = *availableStreams.begin();
> > -
> > -		streams_.push_back(stream);
> > -		availableStreams.erase(stream);
> > -	}
> > -}
> > -
> > -void IPU3CameraConfiguration::adjustStream(StreamConfiguration &cfg, bool scale)
> > -{
> > -	/* The only pixel format the driver supports is NV12. */
> > -	cfg.pixelFormat = formats::NV12;
> > -
> > -	if (scale) {
> > -		/*
> > -		 * Provide a suitable default that matches the sensor aspect
> > -		 * ratio.
> > -		 */
> > -		if (cfg.size.isNull()) {
> > -			cfg.size.width = 1280;
> > -			cfg.size.height = 1280 * cio2Configuration_.size.height
> > -					/ cio2Configuration_.size.width;
> > -		}
> > -
> > -		/*
> > -		 * \todo: Clamp the size to the hardware bounds when we will
> > -		 * figure them out.
> > -		 *
> > -		 * \todo: Handle the scaler (BDS) restrictions. The BDS can
> > -		 * only scale with the same factor in both directions, and the
> > -		 * scaling factor is limited to a multiple of 1/32. At the
> > -		 * moment the ImgU driver hides these constraints by applying
> > -		 * additional cropping, this should be fixed on the driver
> > -		 * side, and cropping should be exposed to us.
> > -		 */
> > -	} else {
> > -		/*
> > -		 * \todo: Properly support cropping when the ImgU driver
> > -		 * interface will be cleaned up.
> > -		 */
> > -		cfg.size = cio2Configuration_.size;
> > -	}
> > -
> > -	/*
> > -	 * Clamp the size to match the ImgU alignment constraints. The width
> > -	 * shall be a multiple of 8 pixels and the height a multiple of 4
> > -	 * pixels.
> > -	 */
> > -	if (cfg.size.width % 8 || cfg.size.height % 4) {
> > -		cfg.size.width &= ~7;
> > -		cfg.size.height &= ~3;
> > -	}
> > -}
> > -
> >  CameraConfiguration::Status IPU3CameraConfiguration::validate()
> >  {
> >  	Status status = Valid;
> > @@ -242,71 +149,141 @@ CameraConfiguration::Status IPU3CameraConfiguration::validate()
> >
> >  	/*
> >  	 * Validate the requested stream configuration and select the sensor
> > -	 * format by collecting the maximum width and height and picking the
> > -	 * closest larger match, as the IPU3 can downscale only. If no
> > -	 * resolution is requested for any stream, or if no sensor resolution is
> > -	 * large enough, pick the largest one.
> > +	 * format by collecting the maximum RAW stream width and height and
> > +	 * picking the closest larger match, as the IPU3 can downscale only. If
> > +	 * no resolution is requested for the RAW stream, use the one from the
> > +	 * largest YUV stream, plus margins pixels for the IF and BDS to scale.
> > +	 * If no resolution is requested for any stream, pick the largest one.
> >  	 */
> >  	unsigned int rawCount = 0;
> >  	unsigned int yuvCount = 0;
> > -	Size size;
> > +	Size maxYuvSize;
> > +	Size maxRawSize;
> >
> >  	for (const StreamConfiguration &cfg : config_) {
> >  		const PixelFormatInfo &info = PixelFormatInfo::info(cfg.pixelFormat);
> >
> > -		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW)
> > +		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW) {
> >  			rawCount++;
> > -		else
> > +			maxRawSize = maxRawSize.expandedTo(cfg.size);
>
> Not something that is needed as a prerequisite for this series, but do
> you think it would be useful to also have in-place versions of the Size
> (and Rectangle) helpers ? This line would become
>
> 			maxRawSize.expandTo(cfg.size);
>

Having chased for like 15 minutes why my Size didn't get update when I
used this, I would really say yes.

> > +		} else {
> >  			yuvCount++;
> > -
> > -		if (cfg.size.width > size.width)
> > -			size.width = cfg.size.width;
> > -		if (cfg.size.height > size.height)
> > -			size.height = cfg.size.height;
> > +			maxYuvSize = maxYuvSize.expandedTo(cfg.size);
> > +		}
> >  	}
> >  	if (rawCount > 1 || yuvCount > 2) {
> >  		LOG(IPU3, Debug)
> >  			<< "Camera configuration not supported";
> >  		return Invalid;
> >  	}
>
> Maybe a blank line here (and above this block too) ?
>
> > +	if (maxRawSize.isNull()) {
> > +		maxRawSize.width = utils::alignUp(maxYuvSize.width,
> > +						  IMGU_OUTPUT_WIDTH_MARGIN);
> > +		maxRawSize.height = utils::alignUp(maxYuvSize.height,
> > +						   IMGU_OUTPUT_HEIGHT_MARGIN);
>
> Maybe
>
> 		maxRawSize = maxYuvSize.alignedUpTo(IMGU_OUTPUT_WIDTH_MARGIN,
> 						    IMGU_OUTPUT_HEIGHT_MARGIN);
>
> ?
>
> > +		maxRawSize = maxRawSize.boundedTo(data_->cio2_.sensor()->resolution());
>
> Or even
>
> 		maxRawSize = maxYuvSize.alignedUpTo(IMGU_OUTPUT_WIDTH_MARGIN,
> 						    IMGU_OUTPUT_HEIGHT_MARGIN)
> 				       .boundedTo(data_->cio2_.sensor()->resolution());
>

Yes, sorry, I got here through several attempts where I mangled sizes
individually and didn't notice I could have used the new Size methods

> > +	}
> >
> > -	/* Generate raw configuration from CIO2. */
> > -	cio2Configuration_ = data_->cio2_.generateConfiguration(size);
> > +	/*
> > +	 * Generate raw configuration from CIO2.
> > +	 *
> > +	 * The output YUV streams will be limited in size to the maximum
> > +	 * frame size requested for the RAW stream.
> > +	 */
> > +	cio2Configuration_ = data_->cio2_.generateConfiguration(maxRawSize);
> >  	if (!cio2Configuration_.pixelFormat.isValid())
> >  		return Invalid;
> >
> > -	/* Assign streams to each configuration entry. */
> > -	assignStreams();
> > +	LOG(IPU3, Debug) << "CIO2 configuration: " << cio2Configuration_.toString();
> >
> > -	/* Verify and adjust configuration if needed. */
> > +	/*
> > +	 * Adjust the configurations if needed and assign streams while
> > +	 * iterating them.
> > +	 */
> > +	bool mainOutputAvailable = true;
> >  	for (unsigned int i = 0; i < config_.size(); ++i) {
> > -		StreamConfiguration &cfg = config_[i];
> > -		const StreamConfiguration oldCfg = cfg;
> > -		const Stream *stream = streams_[i];
> > -
> > -		if (stream == &data_->rawStream_) {
> > -			cfg.size = cio2Configuration_.size;
> > -			cfg.pixelFormat = cio2Configuration_.pixelFormat;
> > -			cfg.bufferCount = cio2Configuration_.bufferCount;
> > +		const PixelFormatInfo &info = PixelFormatInfo::info(config_[i].pixelFormat);
> > +		const StreamConfiguration originalCfg = config_[i];
> > +		StreamConfiguration *cfg = &config_[i];
>
> I'm not asking for this to be changed, but out of curiotiry, why are you
> turning the reference into a pointer ?
>

As we actually modify it's content. This is not a function parameter,
where we enforce that rule, but I still find more natural to use
pointers for things that have to be modified, and references for
things that stay constant.

> > +
> > +		LOG(IPU3, Debug) << "Validating configuration: " << config_[i].toString();
>
> Would it make sense to s/configuration/stream/ ?
>

You probably suggested this already and I missed it.

> > +
> > +
>
> Extra blank line ?
>

Have I missed a checkstyle warning ?

> > +		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW) {
> > +			/* Initialize the RAW stream with the CIO2 configuration. */
> > +			cfg->size = cio2Configuration_.size;
> > +			cfg->pixelFormat = cio2Configuration_.pixelFormat;
> > +			cfg->bufferCount = cio2Configuration_.bufferCount;
> > +			cfg->stride = info.stride(cfg->size.width, 0, 64);
> > +			cfg->frameSize = info.frameSize(cfg->size, 64);
> > +			cfg->setStream(const_cast<Stream *>(&data_->rawStream_));
> > +
> > +			LOG(IPU3, Debug) << "Assigned " << cfg->toString()
> > +					 << " to the raw stream";
> >  		} else {
> > -			bool scale = stream == &data_->vfStream_;
> > -			adjustStream(config_[i], scale);
> > -			cfg.bufferCount = IPU3_BUFFER_COUNT;
> > +			/* Assign and configure the main and viewfinder outputs. */
> > +
> > +			/*
> > +			 * Clamp the size to match the ImgU size limits and the
> > +			 * margins from the CIO2 output frame size.
> > +			 *
> > +			 * The ImgU outputs needs to be rounded down to 64
> > +			 * pixels in width and 32 pixels in height from the
> > +			 * input frame size.
> > +			 *
> > +			 * \todo Verify this assumption and find out if it
> > +			 * depends on the BDS scaling factor of 1/32, as the
> > +			 * main output has no YUV scaler as the viewfinder
> > +			 * output has.
> > +			 */
> > +			unsigned int limit;
> > +			limit = utils::alignDown(cio2Configuration_.size.width - 1,
> > +						 IMGU_OUTPUT_WIDTH_MARGIN);
>
> Where does the - 1 come from ?
>

The ouput sizes have to be strictly smaller than the input frame size.
Here I'm looking for the largest multiple of IMGU_OUTPUT_WIDTH_MARGIN
which is strictly smaller than cio2Configuration_.size.width.

That's for the -1. The reason why I'm searching for a number aligned
to that margin value comes from inspecting the pipe configuration tool
results and the xml files. This seems to be the combination that
satisfies the tool in most cases. I know it's weak as a reasoning, but
I was not able to find out what are the hardware/firmware requirements
that lead to this, if not the way parameters are computed by the
script (which probably reflect how the hw/fw work though).

> > +			cfg->size.width = utils::clamp(cfg->size.width,
> > +						       IMGU_OUTPUT_MIN_SIZE.width,
> > +						       limit);
> > +
> > +			limit = utils::alignDown(cio2Configuration_.size.height - 1,
> > +						 IMGU_OUTPUT_HEIGHT_MARGIN);
> > +			cfg->size.height = utils::clamp(cfg->size.height,
> > +							IMGU_OUTPUT_MIN_SIZE.height,
> > +							limit);
> > +
> > +			cfg->size = cfg->size.alignedDownTo(IMGU_OUTPUT_WIDTH_ALIGN,
> > +							    IMGU_OUTPUT_HEIGHT_ALIGN);
> > +
> > +			cfg->pixelFormat = formats::NV12;
> > +			cfg->bufferCount = IPU3_BUFFER_COUNT;
> > +			cfg->stride = info.stride(cfg->size.width, 0, 1);
> > +			cfg->frameSize = info.frameSize(cfg->size, 1);
> > +
> > +			/*
> > +			 * Use the main output stream in case only one stream is
> > +			 * requested or if the current configuration is the one with
> > +			 * the maximum YUV output size.
> > +			 */
> > +			if (mainOutputAvailable &&
> > +			    (originalCfg.size == maxYuvSize || yuvCount == 1)) {
> > +				cfg->setStream(const_cast<Stream *>(&data_->outStream_));
> > +				mainOutputAvailable = false;
> > +
> > +				LOG(IPU3, Debug) << "Assigned " << cfg->toString()
> > +						 << " to the main output";
> > +			} else {
> > +				cfg->setStream(const_cast<Stream *>(&data_->vfStream_));
> > +
> > +				LOG(IPU3, Debug) << "Assigned " << cfg->toString()
> > +						 << " to the viewfinder output";
> > +			}
> >  		}
> >
> > -		if (cfg.pixelFormat != oldCfg.pixelFormat ||
> > -		    cfg.size != oldCfg.size) {
> > +		if (cfg->pixelFormat != originalCfg.pixelFormat ||
> > +		    cfg->size != originalCfg.size) {
> >  			LOG(IPU3, Debug)
> >  				<< "Stream " << i << " configuration adjusted to "
> > -				<< cfg.toString();
> > +				<< cfg->toString();
> >  			status = Adjusted;
> >  		}
> > -
> > -		const PixelFormatInfo &info = PixelFormatInfo::info(cfg.pixelFormat);
> > -		bool packedRaw = info.colourEncoding == PixelFormatInfo::ColourEncodingRAW;
> > -
> > -		cfg.stride = info.stride(cfg.size.width, 0, packedRaw ? 64 : 1);
> > -		cfg.frameSize = info.frameSize(cfg.size, packedRaw ? 64 : 1);
> >  	}
> >
> >  	return status;
> > @@ -475,16 +452,8 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c)
> >  	bool vfActive = false;
> >
> >  	for (unsigned int i = 0; i < config->size(); ++i) {
> > -		/*
> > -		 * Use a const_cast<> here instead of storing a mutable stream
> > -		 * pointer in the configuration to let the compiler catch
> > -		 * unwanted modifications of camera data in the configuration
> > -		 * validate() implementation.
> > -		 */
> > -		Stream *stream = const_cast<Stream *>(config->streams()[i]);
> >  		StreamConfiguration &cfg = (*config)[i];
> > -
> > -		cfg.setStream(stream);
> > +		Stream *stream = cfg.stream();
> >
> >  		if (stream == outStream) {
> >  			ret = imgu->configureOutput(cfg, &outputFormat);
>
> --
> Regards,
>
> Laurent Pinchart