[libcamera-devel] [RFC 0/6] libcamera: Add support for a RAW still capture stream
Niklas Söderlund
niklas.soderlund at ragnatech.se
Mon Mar 16 03:41:40 CET 2020
Hi,
This series is an RFC for how RAW capture can be added to libcamera. It
implements a RAW stream in the IPU3 pipeline handler as an example. It
targets RAW still image captures and uses a memcpy to copy out the
buffer with the RAW data as soon as it's dequeued from the CIO2. The
copy is needed as the buffer might need to be used in further processing
by the IMGU.
Patch 1/6 Defines a new StillCaptureRaw role which can be used to
applications to generate configurations for raw capture. Patch 2/6 makes
use of this new role in the cam utility.
Patch 3/6 is not ready for consumption as it depends on work submitted
to the DRM subsystem. The patch is however needed as the new DRM formats
are needed to describe the IPU3's RAW pixel format.
Patch 4/6 adds a helper to do the actual memcpy of FrameBuffers. I'm not
really sure it should be declared in buffers.h. Suggestions for a better
location are welcome.
Patch 5/6 and 6/6 deals with implementing the RAW stream into the IPU3
pipeline handler.
This series depends on Laruent's work [1] to use the improved
BufferAllocator with buffer orphaning support. To ease testing [2] may
also be useful to allow cam to write two capture streams content to disk
without conflict.
I have tested this on IPU3 and I can capture both a single RAW stream or
a mix of RAW and video, example with both and writing to disk.
$ ./cam -c1 -s role=video -s role=stillraw -C -F
...
fps: 0.00 stream0 seq: 002055 bytesused: 1382400 stream1 seq: 000001 bytesused: 3269376
fps: 30.30 stream0 seq: 002056 bytesused: 1382400 stream1 seq: 000002 bytesused: 3269376
fps: 30.30 stream0 seq: 002057 bytesused: 1382400 stream1 seq: 000003 bytesused: 3269376
fps: 30.30 stream0 seq: 002058 bytesused: 1382400 stream1 seq: 000004 bytesused: 3269376
...
What I still have to do is find/write a IPU3 RAW frame decoder to verify
the captured RAW frames are good. So far I verified each captured frame
have a different checksum and the captured metadata (sequence nr etc)
make sens.
1. [PATCH 0/9] Simplify buffer management with V4L2 buffer orphaning
2. [PATCH] cam: Create stream names after configuring the camera
Niklas Söderlund (6):
libcamera: stream: Add StillCaptureRaw role
cam: Add option to capture StillCaptureRaw stream
[DNI] include: drm_fourcc: Add Bayer FourCC and modifiers
libcamera: buffer: Add helper to memcopy a FrameBuffer
libcamera: ipu3: Do not unconditionally queue buffers to CIO2
libcamera: ipu3: Add support for a RAW still capture stream
include/libcamera/buffer.h | 1 +
include/libcamera/stream.h | 1 +
include/linux/drm_fourcc.h | 94 +++++++++++++++++
src/cam/main.cpp | 4 +-
src/libcamera/buffer.cpp | 43 ++++++++
src/libcamera/pipeline/ipu3/ipu3.cpp | 152 +++++++++++++++++++++++----
src/libcamera/stream.cpp | 4 +
7 files changed, 279 insertions(+), 20 deletions(-)
--
2.25.1
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