libcamera: stream: Expose stride value

Expose the image stride  which may be retrieved after a video device
has been configured. It may only be retrieved at that point as the
assignment of video devices takes place at this point.

In the future video devices should be assigned at configuration
validation time and the stride value retrieved at that point.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

include/libcamera/stream.h

@@ -42,6 +42,7 @@ struct StreamConfiguration {
 
 	PixelFormat pixelFormat;
 	Size size;
+	unsigned int stride;
 
 	unsigned int bufferCount;
 

src/libcamera/pipeline/ipu3/ipu3.cpp

@@ -77,7 +77,8 @@ public:
 	int configureInput(const Size &size,
 			   V4L2DeviceFormat *inputFormat);
 	int configureOutput(ImgUOutput *output,
-			    const StreamConfiguration &cfg);
+			    const StreamConfiguration &cfg,
+			    V4L2DeviceFormat *outputFormat);
 
 	int allocateBuffers(IPU3CameraData *data, unsigned int bufferCount);
 	void freeBuffers(IPU3CameraData *data);
@@ -546,6 +547,7 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c)
 	IPU3Stream *vfStream = &data->vfStream_;
 	CIO2Device *cio2 = &data->cio2_;
 	ImgUDevice *imgu = data->imgu_;
+	V4L2DeviceFormat outputFormat;
 	int ret;
 
 	/*
@@ -625,12 +627,16 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c)
 		 * The RAW still capture stream just copies buffers from the
 		 * internal queue and doesn't need any specific configuration.
 		 */
-		if (stream->raw_)
-			continue;
+		if (stream->raw_) {
+			cfg.stride = cio2Format.planes[0].bpl;
+		} else {
+			ret = imgu->configureOutput(stream->device_, cfg,
+						    &outputFormat);
+			if (ret)
+				return ret;
 
-		ret = imgu->configureOutput(stream->device_, cfg);
-		if (ret)
-			return ret;
+			cfg.stride = outputFormat.planes[0].bpl;
+		}
 	}
 
 	/*
@@ -639,13 +645,15 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c)
 	 * be at least one active stream in the configuration request).
 	 */
 	if (!outStream->active_) {
-		ret = imgu->configureOutput(outStream->device_, config->at(0));
+		ret = imgu->configureOutput(outStream->device_, config->at(0),
+					    &outputFormat);
 		if (ret)
 			return ret;
 	}
 
 	if (!vfStream->active_) {
-		ret = imgu->configureOutput(vfStream->device_, config->at(0));
+		ret = imgu->configureOutput(vfStream->device_, config->at(0),
+					    &outputFormat);
 		if (ret)
 			return ret;
 	}
@@ -657,7 +665,7 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c)
 	StreamConfiguration statCfg = {};
 	statCfg.size = cio2Format.size;
 
-	ret = imgu->configureOutput(&imgu->stat_, statCfg);
+	ret = imgu->configureOutput(&imgu->stat_, statCfg, &outputFormat);
 	if (ret)
 		return ret;
 
@@ -1166,7 +1174,8 @@ int ImgUDevice::configureInput(const Size &size,
  * \return 0 on success or a negative error code otherwise
  */
 int ImgUDevice::configureOutput(ImgUOutput *output,
-				const StreamConfiguration &cfg)
+				const StreamConfiguration &cfg,
+				V4L2DeviceFormat *outputFormat)
 {
 	V4L2VideoDevice *dev = output->dev;
 	unsigned int pad = output->pad;
@@ -1183,17 +1192,17 @@ int ImgUDevice::configureOutput(ImgUOutput *output,
 	if (output == &stat_)
 		return 0;
 
-	V4L2DeviceFormat outputFormat = {};
-	outputFormat.fourcc = dev->toV4L2PixelFormat(PixelFormat(DRM_FORMAT_NV12));
-	outputFormat.size = cfg.size;
-	outputFormat.planesCount = 2;
+	*outputFormat = {};
+	outputFormat->fourcc = dev->toV4L2PixelFormat(PixelFormat(DRM_FORMAT_NV12));
+	outputFormat->size = cfg.size;
+	outputFormat->planesCount = 2;
 
-	ret = dev->setFormat(&outputFormat);
+	ret = dev->setFormat(outputFormat);
 	if (ret)
 		return ret;
 
 	LOG(IPU3, Debug) << "ImgU " << output->name << " format = "
-			 << outputFormat.toString();
+			 << outputFormat->toString();
 
 	return 0;
 }

src/libcamera/pipeline/rkisp1/rkisp1.cpp

@@ -681,6 +681,7 @@ int PipelineHandlerRkISP1::configure(Camera *camera, CameraConfiguration *c)
 		return ret;
 
 	cfg.setStream(&data->stream_);
+	cfg.stride = outputFormat.planes[0].bpl;
 
 	return 0;
 }

src/libcamera/pipeline/uvcvideo/uvcvideo.cpp

@@ -204,6 +204,7 @@ int PipelineHandlerUVC::configure(Camera *camera, CameraConfiguration *config)
 		return -EINVAL;
 
 	cfg.setStream(&data->stream_);
+	cfg.stride = format.planes[0].bpl;
 
 	return 0;
 }

src/libcamera/pipeline/vimc/vimc.cpp

@@ -253,6 +253,7 @@ int PipelineHandlerVimc::configure(Camera *camera, CameraConfiguration *config)
 		return ret;
 
 	cfg.setStream(&data->stream_);
+	cfg.stride = format.planes[0].bpl;
 
 	return 0;
 }

src/libcamera/stream.cpp

@@ -301,6 +301,19 @@ StreamConfiguration::StreamConfiguration(const StreamFormats &formats)
  * \brief Stream pixel format
  */
 
+/**
+ * \var StreamConfiguration::stride
+ * \brief Image stride for the stream, in bytes
+ *
+ * The stride value reports the number of bytes between the beginning of
+ * successive lines in an image buffer for this stream. The value is
+ * valid after successfully configuring the camera with this
+ * configuration with a call to Camera::Configure().
+ *
+ * \todo Update this value when configuration is validated instead of when
+ * the camera is configured.
+ */
+
 /**
  * \var StreamConfiguration::bufferCount
  * \brief Requested number of buffers to allocate for the stream