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authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>2021-09-02 04:09:18 +0300
committerLaurent Pinchart <laurent.pinchart@ideasonboard.com>2021-09-07 19:18:19 +0300
commitcc035f611f40f366c388bcc2627180349ac671f2 (patch)
treeb0464a8682113a31132673cb7d4976ffe41cec06
parent88589a25318ddf08106262aada6ff71142e42c9d (diff)
libcamera: v4l2_videodevice: Coalesce planes when queuing buffer
When queueing a buffer to a V4L2VideoDevice, the number of planes in the FrameBuffer may not match the number of V4L2 buffer planes if the PixelFormat is multi-planar (has multiple colour planes) and the V4L2 format is single-planar (has a single buffer plane). In this case, we need to coalesce all FrameBuffer planes into a single V4L2 buffer plane. Do so, and add validity checks to reject frame buffers that can't be described using a single V4L2 buffer plane. This change prepares for proper multi-planar support, but isn't expected to result in a change of behaviour with existing pipeline handlers, as none of them queue an output buffer with multiple FrameBuffer planes or use non-contiguous buffers for either capture or output. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
-rw-r--r--src/libcamera/v4l2_videodevice.cpp72
1 files changed, 62 insertions, 10 deletions
diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
index c6c9263c..6c1ca9bb 100644
--- a/src/libcamera/v4l2_videodevice.cpp
+++ b/src/libcamera/v4l2_videodevice.cpp
@@ -22,10 +22,12 @@
#include <libcamera/base/event_notifier.h>
#include <libcamera/base/log.h>
+#include <libcamera/base/utils.h>
#include <libcamera/file_descriptor.h>
#include "libcamera/internal/formats.h"
+#include "libcamera/internal/framebuffer.h"
#include "libcamera/internal/media_device.h"
#include "libcamera/internal/media_object.h"
@@ -1496,10 +1498,25 @@ int V4L2VideoDevice::queueBuffer(FrameBuffer *buffer)
bool multiPlanar = V4L2_TYPE_IS_MULTIPLANAR(buf.type);
const std::vector<FrameBuffer::Plane> &planes = buffer->planes();
+ const unsigned int numV4l2Planes = format_.planesCount;
+
+ /*
+ * Ensure that the frame buffer has enough planes, and that they're
+ * contiguous if the V4L2 format requires them to be.
+ */
+ if (planes.size() < numV4l2Planes) {
+ LOG(V4L2, Error) << "Frame buffer has too few planes";
+ return -EINVAL;
+ }
+
+ if (planes.size() != numV4l2Planes && !buffer->_d()->isContiguous()) {
+ LOG(V4L2, Error) << "Device format requires contiguous buffer";
+ return -EINVAL;
+ }
if (buf.memory == V4L2_MEMORY_DMABUF) {
if (multiPlanar) {
- for (unsigned int p = 0; p < planes.size(); ++p)
+ for (unsigned int p = 0; p < numV4l2Planes; ++p)
v4l2Planes[p].m.fd = planes[p].fd.fd();
} else {
buf.m.fd = planes[0].fd.fd();
@@ -1507,23 +1524,58 @@ int V4L2VideoDevice::queueBuffer(FrameBuffer *buffer)
}
if (multiPlanar) {
- buf.length = planes.size();
+ buf.length = numV4l2Planes;
buf.m.planes = v4l2Planes;
}
if (V4L2_TYPE_IS_OUTPUT(buf.type)) {
const FrameMetadata &metadata = buffer->metadata();
- if (multiPlanar) {
- unsigned int nplane = 0;
- for (const FrameMetadata::Plane &plane : metadata.planes) {
- v4l2Planes[nplane].bytesused = plane.bytesused;
- v4l2Planes[nplane].length = buffer->planes()[nplane].length;
- nplane++;
+ if (numV4l2Planes != planes.size()) {
+ /*
+ * If we have a multi-planar buffer with a V4L2
+ * single-planar format, coalesce all planes. The length
+ * and number of bytes used may only differ in the last
+ * plane as any other situation can't be represented.
+ */
+ unsigned int bytesused = 0;
+ unsigned int length = 0;
+
+ for (auto [i, plane] : utils::enumerate(planes)) {
+ bytesused += metadata.planes[i].bytesused;
+ length += plane.length;
+
+ if (i != planes.size() - 1 && bytesused != length) {
+ LOG(V4L2, Error)
+ << "Holes in multi-planar buffer not supported";
+ return -EINVAL;
+ }
+ }
+
+ if (multiPlanar) {
+ v4l2Planes[0].bytesused = bytesused;
+ v4l2Planes[0].length = length;
+ } else {
+ buf.bytesused = bytesused;
+ buf.length = length;
+ }
+ } else if (multiPlanar) {
+ /*
+ * If we use the multi-planar API, fill in the planes.
+ * The number of planes in the frame buffer and in the
+ * V4L2 buffer is guaranteed to be equal at this point.
+ */
+ for (auto [i, plane] : utils::enumerate(planes)) {
+ v4l2Planes[i].bytesused = metadata.planes[i].bytesused;
+ v4l2Planes[i].length = plane.length;
}
} else {
- if (metadata.planes.size())
- buf.bytesused = metadata.planes[0].bytesused;
+ /*
+ * Single-planar API with a single plane in the buffer
+ * is trivial to handle.
+ */
+ buf.bytesused = metadata.planes[0].bytesused;
+ buf.length = planes[0].length;
}
buf.sequence = metadata.sequence;