[libcamera-devel] [PATCH 6/9] libcamera: pipeline: raspberrypi: Rework stream buffer logic for zero-copy
Naushir Patuck
naush at raspberrypi.com
Mon Jul 13 10:47:25 CEST 2020
Stop using v4l2_videodevice::allocateBuffer() for internal buffers and
instead export/import all buffers. This allows the pipeline to return
any stream buffer requested by the application as zero-copy.
Advertise the Unicam Image stream as the RAW capture stream now.
The RPiStream object now maintains a new list of buffers that are
available to queue into a device. This is needed to distinguish between
FrameBuffers allocated for internal use vs externally provided buffers.
When a Request comes in, if a buffer is not provided for an exported
stream, we re-use a buffer from this list.
Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
.../pipeline/raspberrypi/raspberrypi.cpp | 181 ++++++++----------
.../pipeline/raspberrypi/rpi_stream.h | 136 +++++++++----
2 files changed, 179 insertions(+), 138 deletions(-)
diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
index 2f4255a4..f7e16a6c 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -200,7 +200,8 @@ private:
void checkRequestCompleted();
void tryRunPipeline();
void tryFlushQueues();
- FrameBuffer *updateQueue(std::queue<FrameBuffer *> &q, uint64_t timestamp, V4L2VideoDevice *dev);
+ FrameBuffer *updateQueue(std::queue<FrameBuffer *> &q, uint64_t timestamp,
+ RPi::RPiStream *stream);
unsigned int ispOutputCount_;
};
@@ -523,8 +524,15 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
StreamConfiguration &cfg = config->at(i);
if (isRaw(cfg.pixelFormat)) {
- cfg.setStream(&data->isp_[Isp::Input]);
- data->isp_[Isp::Input].setExternal(true);
+ cfg.setStream(&data->unicam_[Unicam::Image]);
+ /*
+ * We must set both Unicam streams as external, even
+ * though the application may only request RAW frames.
+ * This is because we match timestamps on both streams
+ * to synchronise buffers.
+ */
+ data->unicam_[Unicam::Image].setExternal(true);
+ data->unicam_[Unicam::Embedded].setExternal(true);
continue;
}
@@ -718,14 +726,13 @@ int PipelineHandlerRPi::queueRequestDevice(Camera *camera, Request *request)
if (data->state_ == RPiCameraData::State::Stopped)
return -EINVAL;
- /* Ensure all external streams have associated buffers! */
- for (auto &stream : data->isp_) {
- if (!stream.isExternal())
- continue;
+ LOG(RPI, Debug) << "queueRequestDevice: New request.";
- if (!request->findBuffer(&stream)) {
- LOG(RPI, Error) << "Attempt to queue request with invalid stream.";
- return -ENOENT;
+ /* Push all buffers supplied in the Request to the respective streams. */
+ for (auto stream : data->streams_) {
+ if (stream->isExternal()) {
+ FrameBuffer *buffer = request->findBuffer(stream);
+ stream->queueBuffer(data->dropFrameCount_ ? nullptr : buffer);
}
}
@@ -814,12 +821,10 @@ bool PipelineHandlerRPi::match(DeviceEnumerator *enumerator)
/* Initialize the camera properties. */
data->properties_ = data->sensor_->properties();
- /*
- * List the available output streams.
- * Currently cannot do Unicam streams!
- */
+ /*List the available streams an application may request. */
std::set<Stream *> streams;
- streams.insert(&data->isp_[Isp::Input]);
+ streams.insert(&data->unicam_[Unicam::Image]);
+ streams.insert(&data->unicam_[Unicam::Embedded]);
streams.insert(&data->isp_[Isp::Output0]);
streams.insert(&data->isp_[Isp::Output1]);
streams.insert(&data->isp_[Isp::Stats]);
@@ -896,7 +901,7 @@ int PipelineHandlerRPi::queueAllBuffers(Camera *camera)
int ret;
for (auto const stream : data->streams_) {
- ret = stream->queueBuffers();
+ ret = stream->queueAllBuffers();
if (ret < 0)
return ret;
}
@@ -912,7 +917,8 @@ int PipelineHandlerRPi::prepareBuffers(Camera *camera)
/*
* Decide how many internal buffers to allocate. For now, simply look
* at how many external buffers will be provided. Will need to improve
- * this logic.
+ * this logic. However, we really must have all stream allocate the same
+ * number of buffers to simplify error handling in queueRequestDevice().
*/
unsigned int maxBuffers = 0;
for (const Stream *s : camera->streams())
@@ -920,33 +926,9 @@ int PipelineHandlerRPi::prepareBuffers(Camera *camera)
maxBuffers = std::max(maxBuffers, s->configuration().bufferCount);
for (auto const stream : data->streams_) {
- if (stream->isExternal() || stream->isImporter()) {
- /*
- * If a stream is marked as external reserve memory to
- * prepare to import as many buffers are requested in
- * the stream configuration.
- *
- * If a stream is an internal stream with importer
- * role, reserve as many buffers as possible.
- */
- unsigned int count = stream->isExternal()
- ? stream->configuration().bufferCount
- : maxBuffers;
- ret = stream->importBuffers(count);
- if (ret < 0)
- return ret;
- } else {
- /*
- * If the stream is an internal exporter allocate and
- * export as many buffers as possible to its internal
- * pool.
- */
- ret = stream->allocateBuffers(maxBuffers);
- if (ret < 0) {
- freeBuffers(camera);
- return ret;
- }
- }
+ ret = stream->prepareBuffers(maxBuffers);
+ if (ret < 0)
+ return ret;
}
/*
@@ -954,7 +936,7 @@ int PipelineHandlerRPi::prepareBuffers(Camera *camera)
* the IPA and RPI_IPA_EVENT_SIGNAL_ISP_PREPARE event.
*/
count = 0;
- for (auto const &b : *data->unicam_[Unicam::Image].getBuffers()) {
+ for (auto const &b : data->unicam_[Unicam::Image].getBuffers()) {
b->setCookie(count++);
}
@@ -963,14 +945,14 @@ int PipelineHandlerRPi::prepareBuffers(Camera *camera)
* the IPA.
*/
count = 0;
- for (auto const &b : *data->isp_[Isp::Stats].getBuffers()) {
+ for (auto const &b : data->isp_[Isp::Stats].getBuffers()) {
b->setCookie(count++);
data->ipaBuffers_.push_back({ .id = RPiIpaMask::STATS | b->cookie(),
.planes = b->planes() });
}
count = 0;
- for (auto const &b : *data->unicam_[Unicam::Embedded].getBuffers()) {
+ for (auto const &b : data->unicam_[Unicam::Embedded].getBuffers()) {
b->setCookie(count++);
data->ipaBuffers_.push_back({ .id = RPiIpaMask::EMBEDDED_DATA | b->cookie(),
.planes = b->planes() });
@@ -1081,7 +1063,7 @@ void RPiCameraData::queueFrameAction(unsigned int frame, const IPAOperationData
switch (action.operation) {
case RPI_IPA_ACTION_STATS_METADATA_COMPLETE: {
unsigned int bufferId = action.data[0];
- FrameBuffer *buffer = isp_[Isp::Stats].getBuffers()->at(bufferId).get();
+ FrameBuffer *buffer = isp_[Isp::Stats].getBuffers().at(bufferId);
handleStreamBuffer(buffer, &isp_[Isp::Stats]);
/* Fill the Request metadata buffer with what the IPA has provided */
@@ -1092,19 +1074,19 @@ void RPiCameraData::queueFrameAction(unsigned int frame, const IPAOperationData
case RPI_IPA_ACTION_EMBEDDED_COMPLETE: {
unsigned int bufferId = action.data[0];
- FrameBuffer *buffer = unicam_[Unicam::Embedded].getBuffers()->at(bufferId).get();
+ FrameBuffer *buffer = unicam_[Unicam::Embedded].getBuffers().at(bufferId);
handleStreamBuffer(buffer, &unicam_[Unicam::Embedded]);
break;
}
case RPI_IPA_ACTION_RUN_ISP: {
unsigned int bufferId = action.data[0];
- FrameBuffer *buffer = unicam_[Unicam::Image].getBuffers()->at(bufferId).get();
+ FrameBuffer *buffer = unicam_[Unicam::Image].getBuffers().at(bufferId);
LOG(RPI, Debug) << "Input re-queue to ISP, buffer id " << buffer->cookie()
<< ", timestamp: " << buffer->metadata().timestamp;
- isp_[Isp::Input].dev()->queueBuffer(buffer);
+ isp_[Isp::Input].queueBuffer(buffer);
ispOutputCount_ = 0;
break;
}
@@ -1205,7 +1187,12 @@ void RPiCameraData::ispOutputDequeue(FrameBuffer *buffer)
<< ", buffer id " << buffer->cookie()
<< ", timestamp: " << buffer->metadata().timestamp;
- handleStreamBuffer(buffer, stream);
+ /*
+ * ISP statistics buffer must not be re-queued or sent back to the
+ * application until after the IPA signals so.
+ */
+ if (stream != &isp_[Isp::Stats])
+ handleStreamBuffer(buffer, stream);
/*
* Increment the number of ISP outputs generated.
@@ -1233,8 +1220,12 @@ void RPiCameraData::clearIncompleteRequests()
*/
for (auto const request : requestQueue_) {
for (auto const stream : streams_) {
- if (stream->isExternal())
- stream->dev()->queueBuffer(request->findBuffer(stream));
+ if (!stream->isExternal())
+ continue;
+
+ FrameBuffer *buffer = request->findBuffer(stream);
+ if (buffer)
+ stream->queueBuffer(buffer);
}
}
@@ -1263,7 +1254,7 @@ void RPiCameraData::clearIncompleteRequests()
* Has the buffer already been handed back to the
* request? If not, do so now.
*/
- if (buffer->request())
+ if (buffer && buffer->request())
pipe_->completeBuffer(camera_, request, buffer);
}
@@ -1275,30 +1266,24 @@ void RPiCameraData::clearIncompleteRequests()
void RPiCameraData::handleStreamBuffer(FrameBuffer *buffer, RPi::RPiStream *stream)
{
if (stream->isExternal()) {
- if (!dropFrameCount_) {
- Request *request = buffer->request();
+ Request *request = requestQueue_.front();
+
+ if (!dropFrameCount_ && request->findBuffer(stream) == buffer) {
+ /*
+ * Tag the buffer as completed, returning it to the
+ * application.
+ */
pipe_->completeBuffer(camera_, request, buffer);
+ } else {
+ /*
+ * This buffer was not part of the Request, so we can
+ * recycle it.
+ */
+ stream->returnBuffer(buffer);
}
} else {
- /* Special handling for RAW buffer Requests.
- *
- * The ISP input stream is alway an import stream, but if the
- * current Request has been made for a buffer on the stream,
- * simply memcpy to the Request buffer and requeue back to the
- * device.
- */
- if (stream == &unicam_[Unicam::Image] && !dropFrameCount_) {
- const Stream *rawStream = static_cast<const Stream *>(&isp_[Isp::Input]);
- Request *request = requestQueue_.front();
- FrameBuffer *raw = request->findBuffer(const_cast<Stream *>(rawStream));
- if (raw) {
- raw->copyFrom(buffer);
- pipe_->completeBuffer(camera_, request, raw);
- }
- }
-
- /* Simply requeue the buffer. */
- stream->dev()->queueBuffer(buffer);
+ /* Simply re-queue the buffer to the requested stream. */
+ stream->queueBuffer(buffer);
}
}
@@ -1382,7 +1367,7 @@ void RPiCameraData::tryRunPipeline()
* current bayer buffer will be removed and re-queued to the driver.
*/
embeddedBuffer = updateQueue(embeddedQueue_, bayerBuffer->metadata().timestamp,
- unicam_[Unicam::Embedded].dev());
+ &unicam_[Unicam::Embedded]);
if (!embeddedBuffer) {
LOG(RPI, Debug) << "Could not find matching embedded buffer";
@@ -1401,7 +1386,7 @@ void RPiCameraData::tryRunPipeline()
embeddedBuffer = embeddedQueue_.front();
bayerBuffer = updateQueue(bayerQueue_, embeddedBuffer->metadata().timestamp,
- unicam_[Unicam::Image].dev());
+ &unicam_[Unicam::Image]);
if (!bayerBuffer) {
LOG(RPI, Debug) << "Could not find matching bayer buffer - ending.";
@@ -1409,11 +1394,7 @@ void RPiCameraData::tryRunPipeline()
}
}
- /*
- * Take the first request from the queue and action the IPA.
- * Unicam buffers for the request have already been queued as they come
- * in.
- */
+ /* Take the first request from the queue and action the IPA. */
Request *request = requestQueue_.front();
/*
@@ -1425,12 +1406,6 @@ void RPiCameraData::tryRunPipeline()
op.controls = { request->controls() };
ipa_->processEvent(op);
- /* Queue up any ISP buffers passed into the request. */
- for (auto &stream : isp_) {
- if (stream.isExternal())
- stream.dev()->queueBuffer(request->findBuffer(&stream));
- }
-
/* Ready to use the buffers, pop them off the queue. */
bayerQueue_.pop();
embeddedQueue_.pop();
@@ -1460,32 +1435,42 @@ void RPiCameraData::tryFlushQueues()
* and give a chance for the hardware to return to lock-step. We do have
* to drop all interim frames.
*/
- if (unicam_[Unicam::Image].getBuffers()->size() == bayerQueue_.size() &&
- unicam_[Unicam::Embedded].getBuffers()->size() == embeddedQueue_.size()) {
+ if (unicam_[Unicam::Image].getBuffers().size() == bayerQueue_.size() &&
+ unicam_[Unicam::Embedded].getBuffers().size() == embeddedQueue_.size()) {
+ /* This cannot happen when Unicam streams are external. */
+ assert(!unicam_[Unicam::Image].isExternal());
+
LOG(RPI, Warning) << "Flushing all buffer queues!";
while (!bayerQueue_.empty()) {
- unicam_[Unicam::Image].dev()->queueBuffer(bayerQueue_.front());
+ unicam_[Unicam::Image].queueBuffer(bayerQueue_.front());
bayerQueue_.pop();
}
while (!embeddedQueue_.empty()) {
- unicam_[Unicam::Embedded].dev()->queueBuffer(embeddedQueue_.front());
+ unicam_[Unicam::Embedded].queueBuffer(embeddedQueue_.front());
embeddedQueue_.pop();
}
}
}
FrameBuffer *RPiCameraData::updateQueue(std::queue<FrameBuffer *> &q, uint64_t timestamp,
- V4L2VideoDevice *dev)
+ RPi::RPiStream *stream)
{
+ /*
+ * If the unicam streams are external (both have to the same), then we
+ * can only return out the top buffer in the queue, and assume they have
+ * been synced by queuing at the same time. We cannot drop these frames,
+ * as they may have been provided externally.
+ */
while (!q.empty()) {
FrameBuffer *b = q.front();
- if (b->metadata().timestamp < timestamp) {
+ if (!stream->isExternal() && b->metadata().timestamp < timestamp) {
q.pop();
- dev->queueBuffer(b);
- LOG(RPI, Warning) << "Dropping input frame!";
- } else if (b->metadata().timestamp == timestamp) {
+ stream->queueBuffer(b);
+ LOG(RPI, Warning) << "Dropping unmatched input frame in stream "
+ << stream->name();
+ } else if (stream->isExternal() || b->metadata().timestamp == timestamp) {
/* The calling function will pop the item from the queue. */
return b;
} else {
diff --git a/src/libcamera/pipeline/raspberrypi/rpi_stream.h b/src/libcamera/pipeline/raspberrypi/rpi_stream.h
index ed4f4987..a6f573fa 100644
--- a/src/libcamera/pipeline/raspberrypi/rpi_stream.h
+++ b/src/libcamera/pipeline/raspberrypi/rpi_stream.h
@@ -44,30 +44,20 @@ public:
void setExternal(bool external)
{
+ /* Import streams cannot be external. */
+ assert(!external || !importOnly_);
external_ = external;
}
bool isExternal() const
{
- /*
- * Import streams cannot be external.
- *
- * RAW capture is a special case where we simply copy the RAW
- * buffer out of the request. All other buffer handling happens
- * as if the stream is internal.
- */
- return external_ && !importOnly_;
- }
-
- bool isImporter() const
- {
- return importOnly_;
+ return external_;
}
void reset()
{
external_ = false;
- internalBuffers_.clear();
+ clearBuffers();
}
std::string name() const
@@ -77,67 +67,124 @@ public:
void setExternalBuffers(std::vector<std::unique_ptr<FrameBuffer>> *buffers)
{
- externalBuffers_ = buffers;
+ std::transform(buffers->begin(), buffers->end(), std::back_inserter(bufferList_),
+ [](std::unique_ptr<FrameBuffer> &b) { return b.get(); });
}
- const std::vector<std::unique_ptr<FrameBuffer>> *getBuffers() const
+ const std::vector<FrameBuffer *> &getBuffers() const
{
- return external_ ? externalBuffers_ : &internalBuffers_;
+ return bufferList_;
}
void releaseBuffers()
{
dev_->releaseBuffers();
- if (!external_ && !importOnly_)
- internalBuffers_.clear();
+ clearBuffers();
}
- int importBuffers(unsigned int count)
+ int prepareBuffers(unsigned int count)
{
+ int ret;
+
+ if (!importOnly_) {
+ if (count) {
+ /* Export some frame buffers for internal use. */
+ ret = dev_->exportBuffers(count, &internalBuffers_);
+ if (ret < 0)
+ return ret;
+
+ /* Add these exported buffers to the internal/external buffer list. */
+ std::transform(internalBuffers_.begin(), internalBuffers_.end(),
+ std::back_inserter(bufferList_),
+ [](std::unique_ptr<FrameBuffer> &b) { return b.get(); });
+
+ /* Add these buffers to the queue of internal usable buffers. */
+ for (auto const &buffer : internalBuffers_)
+ availableBuffers_.push(buffer.get());
+ }
+
+ /* We must import all internal/external exported buffers. */
+ count = bufferList_.size();
+ }
+
return dev_->importBuffers(count);
}
- int allocateBuffers(unsigned int count)
+ int queueAllBuffers()
{
- return dev_->allocateBuffers(count, &internalBuffers_);
- }
+ int ret;
- int queueBuffers()
- {
if (external_)
return 0;
- for (auto &b : internalBuffers_) {
- int ret = dev_->queueBuffer(b.get());
- if (ret) {
- LOG(RPISTREAM, Error) << "Failed to queue buffers for "
- << name_;
+ while (!availableBuffers_.empty()) {
+ ret = queueBuffer(availableBuffers_.front());
+ if (ret < 0)
return ret;
- }
+
+ availableBuffers_.pop();
}
return 0;
}
- bool findFrameBuffer(FrameBuffer *buffer) const
+ int queueBuffer(FrameBuffer *buffer)
{
- auto start = external_ ? externalBuffers_->begin() : internalBuffers_.begin();
- auto end = external_ ? externalBuffers_->end() : internalBuffers_.end();
+ /*
+ * A nullptr buffer implies an external stream, but no external
+ * buffer has been supplied. So, pick one from the availableBuffers_
+ * queue.
+ */
+ if (!buffer) {
+ if (availableBuffers_.empty()) {
+ LOG(RPISTREAM, Warning) << "No buffers available for "
+ << name_;
+ return -EINVAL;
+ }
+ buffer = availableBuffers_.front();
+ availableBuffers_.pop();
+ }
+
+ LOG(RPISTREAM, Debug) << "Queuing buffer " << buffer->cookie()
+ << " for " << name_;
+
+ int ret = dev_->queueBuffer(buffer);
+ if (ret) {
+ LOG(RPISTREAM, Error) << "Failed to queue buffer for "
+ << name_;
+ }
+
+ return ret;
+ }
+
+ void returnBuffer(FrameBuffer *buffer)
+ {
+ availableBuffers_.push(buffer);
+ }
+
+ bool findFrameBuffer(FrameBuffer *buffer) const
+ {
if (importOnly_)
return false;
- if (std::find_if(start, end,
- [buffer](std::unique_ptr<FrameBuffer> const &ref) { return ref.get() == buffer; }) != end)
+ if (std::find(bufferList_.begin(), bufferList_.end(), buffer) != bufferList_.end())
return true;
return false;
}
private:
+ void clearBuffers()
+ {
+ availableBuffers_ = std::queue<FrameBuffer *>{};
+ internalBuffers_.clear();
+ bufferList_.clear();
+ }
+
/*
* Indicates that this stream is active externally, i.e. the buffers
- * are provided by the application.
+ * might be provided by (and returned to) the application.
*/
bool external_;
/* Indicates that this stream only imports buffers, e.g. ISP input. */
@@ -146,10 +193,19 @@ private:
std::string name_;
/* The actual device stream. */
std::unique_ptr<V4L2VideoDevice> dev_;
- /* Internally allocated framebuffers associated with this device stream. */
+ /* All framebuffers associated with this device stream. */
+ std::vector<FrameBuffer *> bufferList_;
+ /*
+ * List of frame buffer that we can use if none have been provided by
+ * the application for external streams. This is populated by the
+ * buffers exported internally.
+ */
+ std::queue<FrameBuffer *> availableBuffers_;
+ /*
+ * This is a list of buffers exported internally. Need to keep this around
+ * as the stream needs to maintain ownership of these buffers.
+ */
std::vector<std::unique_ptr<FrameBuffer>> internalBuffers_;
- /* Externally allocated framebuffers associated with this device stream. */
- std::vector<std::unique_ptr<FrameBuffer>> *externalBuffers_;
};
/*
--
2.25.1
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