From d1d1348228d559999fc8ec48596fb699ab3563c0 Mon Sep 17 00:00:00 2001 From: Nicolas Dufresne Date: Mon, 27 Jan 2020 17:46:22 -0500 Subject: gst: libcamerasrc: Implement initial streaming With this patch, the element is now able to push buffers to the next element in the graph. The buffers are currently missing any metadata like timestamp, sequence number. This will be added in the next commit. Signed-off-by: Nicolas Dufresne Reviewed-by: Laurent Pinchart Signed-off-by: Laurent Pinchart --- src/gstreamer/gstlibcamerasrc.cpp | 192 +++++++++++++++++++++++++++++++++++++- 1 file changed, 191 insertions(+), 1 deletion(-) (limited to 'src/gstreamer/gstlibcamerasrc.cpp') diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp index dfbf092e..0b4cae79 100644 --- a/src/gstreamer/gstlibcamerasrc.cpp +++ b/src/gstreamer/gstlibcamerasrc.cpp @@ -14,8 +14,11 @@ #include "gstlibcamerasrc.h" +#include #include +#include + #include #include @@ -29,12 +32,71 @@ using namespace libcamera; GST_DEBUG_CATEGORY_STATIC(source_debug); #define GST_CAT_DEFAULT source_debug +struct RequestWrap { + RequestWrap(Request *request); + ~RequestWrap(); + + void attachBuffer(GstBuffer *buffer); + GstBuffer *detachBuffer(Stream *stream); + + /* For ptr comparison only. */ + Request *request_; + std::map buffers_; +}; + +RequestWrap::RequestWrap(Request *request) + : request_(request) +{ +} + +RequestWrap::~RequestWrap() +{ + for (std::pair &item : buffers_) { + if (item.second) + gst_buffer_unref(item.second); + } +} + +void RequestWrap::attachBuffer(GstBuffer *buffer) +{ + FrameBuffer *fb = gst_libcamera_buffer_get_frame_buffer(buffer); + Stream *stream = gst_libcamera_buffer_get_stream(buffer); + + request_->addBuffer(stream, fb); + + auto item = buffers_.find(stream); + if (item != buffers_.end()) { + gst_buffer_unref(item->second); + item->second = buffer; + } else { + buffers_[stream] = buffer; + } +} + +GstBuffer *RequestWrap::detachBuffer(Stream *stream) +{ + GstBuffer *buffer = nullptr; + + auto item = buffers_.find(stream); + if (item != buffers_.end()) { + buffer = item->second; + item->second = nullptr; + } + + return buffer; +} + /* Used for C++ object with destructors. */ struct GstLibcameraSrcState { + GstLibcameraSrc *src_; + std::unique_ptr cm_; std::shared_ptr cam_; std::unique_ptr config_; std::vector srcpads_; + std::queue> requests_; + + void requestCompleted(Request *request); }; struct _GstLibcameraSrc { @@ -47,6 +109,7 @@ struct _GstLibcameraSrc { GstLibcameraSrcState *state; GstLibcameraAllocator *allocator; + GstFlowCombiner *flow_combiner; }; enum { @@ -70,6 +133,41 @@ GstStaticPadTemplate request_src_template = { "src_%s", GST_PAD_SRC, GST_PAD_REQUEST, TEMPLATE_CAPS }; +void +GstLibcameraSrcState::requestCompleted(Request *request) +{ + GLibLocker lock(GST_OBJECT(src_)); + + GST_DEBUG_OBJECT(src_, "buffers are ready"); + + std::unique_ptr wrap = std::move(requests_.front()); + requests_.pop(); + + g_return_if_fail(wrap->request_ == request); + + if ((request->status() == Request::RequestCancelled)) { + GST_DEBUG_OBJECT(src_, "Request was cancelled"); + return; + } + + GstBuffer *buffer; + for (GstPad *srcpad : srcpads_) { + Stream *stream = gst_libcamera_pad_get_stream(srcpad); + buffer = wrap->detachBuffer(stream); + gst_libcamera_pad_queue_buffer(srcpad, buffer); + } + + { + /* We only want to resume the task if it's paused. */ + GstTask *task = src_->task; + GLibLocker lock(GST_OBJECT(task)); + if (GST_TASK_STATE(task) == GST_TASK_PAUSED) { + GST_TASK_STATE(task) = GST_TASK_STARTED; + GST_TASK_SIGNAL(task); + } + } +} + static bool gst_libcamera_src_open(GstLibcameraSrc *self) { @@ -122,6 +220,8 @@ gst_libcamera_src_open(GstLibcameraSrc *self) return false; } + cam->requestCompleted.connect(self->state, &GstLibcameraSrcState::requestCompleted); + /* No need to lock here, we didn't start our threads yet. */ self->state->cm_ = std::move(cm); self->state->cam_ = cam; @@ -133,8 +233,77 @@ static void gst_libcamera_src_task_run(gpointer user_data) { GstLibcameraSrc *self = GST_LIBCAMERA_SRC(user_data); + GstLibcameraSrcState *state = self->state; + + Request *request = state->cam_->createRequest(); + auto wrap = std::make_unique(request); + for (GstPad *srcpad : state->srcpads_) { + GstLibcameraPool *pool = gst_libcamera_pad_get_pool(srcpad); + GstBuffer *buffer; + GstFlowReturn ret; + + ret = gst_buffer_pool_acquire_buffer(GST_BUFFER_POOL(pool), + &buffer, nullptr); + if (ret != GST_FLOW_OK) { + /* + * RequestWrap does not take ownership, and we won't be + * queueing this one due to lack of buffers. + */ + delete request; + request = nullptr; + break; + } + + wrap->attachBuffer(buffer); + } + + if (request) { + GLibLocker lock(GST_OBJECT(self)); + GST_TRACE_OBJECT(self, "Requesting buffers"); + state->cam_->queueRequest(request); + state->requests_.push(std::move(wrap)); + } + + GstFlowReturn ret = GST_FLOW_OK; + gst_flow_combiner_reset(self->flow_combiner); + for (GstPad *srcpad : state->srcpads_) { + ret = gst_libcamera_pad_push_pending(srcpad); + ret = gst_flow_combiner_update_pad_flow(self->flow_combiner, + srcpad, ret); + } - GST_DEBUG_OBJECT(self, "Streaming thread is now capturing"); + { + /* + * Here we need to decide if we want to pause or stop the task. This + * needs to happen in lock step with the callback thread which may want + * to resume the task. + */ + GLibLocker lock(GST_OBJECT(self)); + if (ret != GST_FLOW_OK) { + if (ret == GST_FLOW_EOS) { + g_autoptr(GstEvent) eos = gst_event_new_eos(); + guint32 seqnum = gst_util_seqnum_next(); + gst_event_set_seqnum(eos, seqnum); + for (GstPad *srcpad : state->srcpads_) + gst_pad_push_event(srcpad, gst_event_ref(eos)); + } else if (ret != GST_FLOW_FLUSHING) { + GST_ELEMENT_FLOW_ERROR(self, ret); + } + gst_task_stop(self->task); + return; + } + + bool do_pause = true; + for (GstPad *srcpad : state->srcpads_) { + if (gst_libcamera_pad_has_pending(srcpad)) { + do_pause = false; + break; + } + } + + if (do_pause) + gst_task_pause(self->task); + } } static void @@ -233,12 +402,23 @@ gst_libcamera_src_task_enter(GstTask *task, GThread *thread, gpointer user_data) return; } + self->flow_combiner = gst_flow_combiner_new(); for (gsize i = 0; i < state->srcpads_.size(); i++) { GstPad *srcpad = state->srcpads_[i]; const StreamConfiguration &stream_cfg = state->config_->at(i); GstLibcameraPool *pool = gst_libcamera_pool_new(self->allocator, stream_cfg.stream()); gst_libcamera_pad_set_pool(srcpad, pool); + gst_flow_combiner_add_pad(self->flow_combiner, srcpad); + } + + ret = state->cam_->start(); + if (ret) { + GST_ELEMENT_ERROR(self, RESOURCE, SETTINGS, + ("Failed to start the camera: %s", g_strerror(-ret)), + ("Camera.start() failed with error code %i", ret)); + gst_task_stop(task); + return; } done: @@ -260,10 +440,14 @@ gst_libcamera_src_task_leave(GstTask *task, GThread *thread, gpointer user_data) GST_DEBUG_OBJECT(self, "Streaming thread is about to stop"); + state->cam_->stop(); + for (GstPad *srcpad : state->srcpads_) gst_libcamera_pad_set_pool(srcpad, nullptr); g_clear_object(&self->allocator); + g_clear_pointer(&self->flow_combiner, + (GDestroyNotify)gst_flow_combiner_free); } static void @@ -343,6 +527,9 @@ gst_libcamera_src_change_state(GstElement *element, GstStateChange transition) return GST_STATE_CHANGE_FAILURE; ret = GST_STATE_CHANGE_NO_PREROLL; break; + case GST_STATE_CHANGE_PAUSED_TO_PLAYING: + gst_task_start(self->task); + break; case GST_STATE_CHANGE_PLAYING_TO_PAUSED: ret = GST_STATE_CHANGE_NO_PREROLL; break; @@ -394,6 +581,9 @@ gst_libcamera_src_init(GstLibcameraSrc *self) state->srcpads_.push_back(gst_pad_new_from_template(templ, "src")); gst_element_add_pad(GST_ELEMENT(self), state->srcpads_[0]); + + /* C-style friend. */ + state->src_ = self; self->state = state; } -- cgit v1.2.1