libcamera: pipeline: simple: Reset format on capture side of converter

When configuring the converter, the format is first set on the output
side based on the format of the camera pipeline output, and then the
format is set on the capture side to match the desired stream
configuration. The format parameter passed to
V4L2VideoDevice::setFormat() uses the same variable for both calls,
which has the unwanted side effect of carrying plane configuration from
the output side to the capture side of the converter. In particular, the
stride or plane size requested on the capture side can become
unnecessarily large when converting to a format with a lower number of
bits per pixel (for instance converting YUYV to NV12).

Fix this by resetting the format variable before using it to configure
the capture side.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/libcamera/pipeline/simple/converter.cpp b/src/libcamera/pipeline/simple/converter.cpp
index 57538ab0..67e6e864 100644
--- a/src/libcamera/pipeline/simple/converter.cpp
+++ b/src/libcamera/pipeline/simple/converter.cpp
@@ -164,6 +164,7 @@ int SimpleConverter::configure(PixelFormat inputFormat, const Size &inputSize,
 
 	/* Set the pixel format and size on the output. */
 	videoFormat = m2m_->capture()->toV4L2PixelFormat(cfg->pixelFormat);
+	format = {};
 	format.fourcc = videoFormat;
 	format.size = cfg->size;