[libcamera-devel] [PATCH v2 04/10] pipeline: raspberrypi: Read config parameters from a file
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Fri Dec 2 21:44:53 CET 2022
Hi Naush,
It's me again :-) Please see below for another comment.
On Tue, Nov 29, 2022 at 01:45:28PM +0000, Naushir Patuck via libcamera-devel wrote:
> Read the platform configuration parameters from default.json config file. Use
> the PipelineHandler::configurationFile() helper to determine the full path of
> the file. The default.json filename can be overridden by the user setting the
> LIBCAMERA_RPI_CONFIG_FILE environment variable giving the full path of the
> custom file.
>
> Add config parameter validation to ensure bad parameters cannot cause the
> pipeline handler to stop working.
>
> Currently three parameters are available through the json file:
>
> "min_unicam_buffers"
> The minimum number of internal Unicam buffers to allocate.
>
> "min_total_unicam_buffers"
> The minimum number of internal + external Unicam buffers that must be allocated.
>
> "num_output0_buffers"
> Number of internal ISP Output0 buffers to allocate.
>
> Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> Reviewed-by: David Plowman <david.plowman at raspberrypi.com>
> ---
> .../pipeline/raspberrypi/data/default.json | 20 ++++++
> .../pipeline/raspberrypi/data/meson.build | 8 +++
> .../pipeline/raspberrypi/meson.build | 2 +
> .../pipeline/raspberrypi/raspberrypi.cpp | 61 +++++++++++++++++++
> 4 files changed, 91 insertions(+)
> create mode 100644 src/libcamera/pipeline/raspberrypi/data/default.json
> create mode 100644 src/libcamera/pipeline/raspberrypi/data/meson.build
>
> diff --git a/src/libcamera/pipeline/raspberrypi/data/default.json b/src/libcamera/pipeline/raspberrypi/data/default.json
> new file mode 100644
> index 000000000000..d709e31850af
> --- /dev/null
> +++ b/src/libcamera/pipeline/raspberrypi/data/default.json
> @@ -0,0 +1,20 @@
> +{
> + "version": 1.0,
> + "target": "bcm2835",
> +
> + "pipeline_handler":
> + {
> + # The minimum number of internal buffers to be allocated for Unicam.
> + # This value must be greater than 0, but less than or equal to min_total_unicam_buffers.
> + "min_unicam_buffers": 2,
> +
> + # The minimum total (internal + external) buffer count used for Unicam.
> + # The number of internal buffers allocated for Unicam is given by:
> + # internal buffer count = max(min_unicam_buffers,
> + # min_total_unicam_buffers - external buffer count)
> + "min_total_unicam_buffers": 4,
> +
> + # The number of internal buffers used for ISP Output0. This must be set to 1.
> + "num_output0_buffers": 1
> + }
> +}
> diff --git a/src/libcamera/pipeline/raspberrypi/data/meson.build b/src/libcamera/pipeline/raspberrypi/data/meson.build
> new file mode 100644
> index 000000000000..232f8b43c5fd
> --- /dev/null
> +++ b/src/libcamera/pipeline/raspberrypi/data/meson.build
> @@ -0,0 +1,8 @@
> +# SPDX-License-Identifier: CC0-1.0
> +
> +conf_files = files([
> + 'default.json',
> +])
> +
> +install_data(conf_files,
> + install_dir : libcamera_datadir / 'pipeline/raspberrypi')
> diff --git a/src/libcamera/pipeline/raspberrypi/meson.build b/src/libcamera/pipeline/raspberrypi/meson.build
> index f1a2f5ee72c2..48235f887501 100644
> --- a/src/libcamera/pipeline/raspberrypi/meson.build
> +++ b/src/libcamera/pipeline/raspberrypi/meson.build
> @@ -5,3 +5,5 @@ libcamera_sources += files([
> 'raspberrypi.cpp',
> 'rpi_stream.cpp',
> ])
> +
> +subdir('data')
> diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> index f2b695af2399..ce411453db0a 100644
> --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> @@ -14,6 +14,7 @@
> #include <unordered_set>
> #include <utility>
>
> +#include <libcamera/base/file.h>
> #include <libcamera/base/shared_fd.h>
> #include <libcamera/base/utils.h>
>
> @@ -40,6 +41,7 @@
> #include "libcamera/internal/media_device.h"
> #include "libcamera/internal/pipeline_handler.h"
> #include "libcamera/internal/v4l2_videodevice.h"
> +#include "libcamera/internal/yaml_parser.h"
>
> #include "dma_heaps.h"
> #include "rpi_stream.h"
> @@ -313,6 +315,7 @@ public:
> };
>
> Config config_;
> + unsigned int numUnicamBuffers;
>
> private:
> void checkRequestCompleted();
> @@ -1154,6 +1157,19 @@ int PipelineHandlerRPi::queueRequestDevice(Camera *camera, Request *request)
> */
> stream->setExternalBuffer(buffer);
> }
> +
> + if (!buffer) {
> + if (stream == &data->isp_[Isp::Output0] && !data->config_.numOutput0Buffers) {
> + LOG(RPI, Error) << "Output0 buffer must be provided in the request.";
> + return -EINVAL;
> + }
> +
> + if (stream == &data->unicam_[Unicam::Image] && !data->numUnicamBuffers) {
> + LOG(RPI, Error) << "Unicam Image buffer must be provided in the request.";
> + return -EINVAL;
> + }
The numOutput0Buffers and minUnicamBuffers configuration parameters seem
to me to be a contract between the application and libcamera, where
setting them to 0 requires the application to always pass buffers for
the corresponding streams. As we discussed previously, while I'm fine
with the concept of a configuration file to tune the behaviour of the
camera, I'm bothered by conveing information about such an API contract
through a file.
Could we instead add a hint to the StreamConfiguration class to let
applications tell about their side of the contract ? Something along the
lines of
diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h
index 29235ddf0d8a..616f6dd174f1 100644
--- a/include/libcamera/stream.h
+++ b/include/libcamera/stream.h
@@ -13,6 +13,8 @@
#include <string>
#include <vector>
+#include <libcamera/base/flags.h>
+
#include <libcamera/color_space.h>
#include <libcamera/framebuffer.h>
#include <libcamera/geometry.h>
@@ -39,6 +41,13 @@ private:
};
struct StreamConfiguration {
+ enum class Hint {
+ None = 0,
+ MandatoryBuffer = (1 << 0),
+ };
+
+ using Hints = Flags<Hint>;
+
StreamConfiguration();
StreamConfiguration(const StreamFormats &formats);
@@ -50,6 +59,7 @@ struct StreamConfiguration {
unsigned int bufferCount;
std::optional<ColorSpace> colorSpace;
+ Hints hints;
Stream *stream() const { return stream_; }
void setStream(Stream *stream) { stream_ = stream; }
(names to be bikeshedded of course)
> + }
> +
> /*
> * If no buffer is provided by the request for this stream, we
> * queue a nullptr to the stream to signify that it must use an
> @@ -1419,6 +1435,7 @@ int PipelineHandlerRPi::registerCamera(MediaDevice *unicam, MediaDevice *isp, Me
> int PipelineHandlerRPi::configurePipelineHandler(RPiCameraData *data)
> {
> RPiCameraData::Config &config = data->config_;
> + std::string filename;
>
> config = {
> .minUnicamBuffers = 2,
> @@ -1426,6 +1443,49 @@ int PipelineHandlerRPi::configurePipelineHandler(RPiCameraData *data)
> .numOutput0Buffers = 1,
> };
>
> + char const *configFromEnv = utils::secure_getenv("LIBCAMERA_RPI_CONFIG_FILE");
> + if (!configFromEnv || *configFromEnv == '\0')
> + filename = configurationFile("raspberrypi", "default.json");
> + else
> + filename = std::string(configFromEnv);
> +
> + if (filename.empty())
> + return -EINVAL;
> +
> + File file(filename);
> + if (!file.open(File::OpenModeFlag::ReadOnly)) {
> + LOG(RPI, Error) << "Failed to open configuration file '" << filename << "'";
> + return -EIO;
> + }
> +
> + LOG(RPI, Info) << "Using configuration file '" << filename << "'";
> +
> + std::unique_ptr<YamlObject> root = YamlParser::parse(file);
> + if (!root) {
> + LOG(RPI, Error) << "Failed to parse configuration file, using defaults!";
> + return -EINVAL;
> + }
> +
> + ASSERT((*root)["version"].get<double>() == 1.0);
> +
> + const YamlObject &phConfig = (*root)["pipeline_handler"];
> + config.minUnicamBuffers =
> + phConfig["min_unicam_buffers"].get<unsigned int>(config.minUnicamBuffers);
> + config.minTotalUnicamBuffers =
> + phConfig["min_total_unicam_buffers"].get<unsigned int>(config.minTotalUnicamBuffers);
> + config.numOutput0Buffers =
> + phConfig["num_output0_buffers"].get<unsigned int>(config.numOutput0Buffers);
> +
> + if (config.minTotalUnicamBuffers < config.minUnicamBuffers) {
> + LOG(RPI, Error) << "Invalid configuration: min_total_unicam_buffers must be >= min_unicam_buffers!";
> + return -EINVAL;
> + }
> +
> + if (config.minTotalUnicamBuffers < 1) {
> + LOG(RPI, Error) << "Invalid configuration: min_total_unicam_buffers must be >= 1!";
> + return -EINVAL;
> + }
> +
> return 0;
> }
>
> @@ -1492,6 +1552,7 @@ int PipelineHandlerRPi::prepareBuffers(Camera *camera)
> */
> numBuffers = std::max<int>(data->config_.minUnicamBuffers,
> minBuffers - numRawBuffers);
> + data->numUnicamBuffers = numBuffers;
> } else if (stream == &data->isp_[Isp::Input]) {
> /*
> * ISP input buffers are imported from Unicam, so follow
--
Regards,
Laurent Pinchart
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