Add UVC still capture support

cpp/uvc/src/uvc_example.cpp

@@ -35,7 +35,8 @@ extern "C" {
 std::atomic<bool> quitEvent(false);
 
 std::shared_ptr<dai::InputQueue> inputQueue{nullptr};
-std::shared_ptr<dai::MessageQueue> outputQueue;
+std::shared_ptr<dai::MessageQueue> videoBitstreamQueue{nullptr};
+std::shared_ptr<dai::MessageQueue> stillBitstreamQueue{nullptr};
 
 /* Necessary for and only used by signal handler. */
 static struct events *sigint_events;
@@ -48,49 +49,30 @@ void signalHandler(int signum) {
 	events_stop(sigint_events);
 }
 
-// Custom host node for saving video data
-class VideoSaver : public dai::node::CustomNode<VideoSaver> {
-   public:
-    VideoSaver() : fileHandle("video.encoded", std::ios::binary) {
-        if(!fileHandle.is_open()) {
-            throw std::runtime_error("Could not open video.encoded for writing");
-        }
-    }
-
-    ~VideoSaver() {
-        if(fileHandle.is_open()) {
-            fileHandle.close();
-        }
-    }
-
-    std::shared_ptr<dai::Buffer> processGroup(std::shared_ptr<dai::MessageGroup> message) override {
-        if(!fileHandle.is_open()) return nullptr;
 
-        // Get raw data and write to file
-        auto frame = message->get<dai::EncodedFrame>("data");
-        unsigned char* frameData = frame->getData().data();
-        size_t frameSize = frame->getData().size();
-        std::cout << "Storing frame of size: " << frameSize << std::endl;
-        fileHandle.write(reinterpret_cast<const char*>(frameData), frameSize);
+extern "C" void depthai_uvc_get_buffer(struct video_source *s, struct video_buffer *buf, bool still) {
+    unsigned int frame_size, size;
+    uint8_t *f;
 
-        // Don't send anything back
-        return nullptr;
+    if(quitEvent) {
+        std::cout << "depthai_uvc_get_buffer(): Stopping capture due to quit event." << std::endl;
+        return;
     }
 
-   private:
-    std::ofstream fileHandle;
-};
+    if(still) {
+        std::cout << "depthai_uvc_get_buffer(): Sending latest full-resolution frame as still image." << std::endl;
 
-extern "C" void depthai_uvc_get_buffer(struct video_source *s, struct video_buffer *buf) {
-	unsigned int frame_size, size;
-    uint8_t *f;
+        auto frame = stillBitstreamQueue->get<dai::ImgFrame>();
 
-    if(quitEvent) {
-        std::cout << "depthai_uvc_get_buffer(): Stopping capture due to quit event." << std::endl;
+        f = frame->getData().data();
+        frame_size = frame->getData().size();
+        size = std::min(frame_size, buf->size);
+        memcpy(buf->mem, f, size);
+        buf->bytesused = size;
         return;
-    }      
+    }
 
-    auto frame = outputQueue->get<dai::ImgFrame>();
+    auto frame = videoBitstreamQueue->get<dai::ImgFrame>();
     if(frame == nullptr) {
         std::cerr << "depthai_uvc_get_buffer(): No frame available." << std::endl;
         return;
@@ -176,13 +158,20 @@ int main() {
     // Create nodes
     auto camRgb = pipeline.create<dai::node::Camera>()->build(socket);
     inputQueue  = camRgb->inputControl.createInputQueue();
-    auto output = camRgb->requestOutput(std::make_pair(1920, 1080), dai::ImgFrame::Type::NV12);
-
-    // Create video encoder node
-    auto encoded = pipeline.create<dai::node::VideoEncoder>();
-    encoded->setDefaultProfilePreset(30, dai::VideoEncoderProperties::Profile::MJPEG);
-    output->link(encoded->input);
-    outputQueue = encoded->bitstream.createOutputQueue(1, false);
+    auto videoSource = camRgb->requestOutput(std::make_pair(1920, 1080), dai::ImgFrame::Type::NV12);
+
+    // Encode the center-cropped HD stream for continuous UVC video.
+    auto videoEncoder = pipeline.create<dai::node::VideoEncoder>();
+    videoEncoder->setDefaultProfilePreset(30, dai::VideoEncoderProperties::Profile::MJPEG);
+    videoSource->link(videoEncoder->input);
+    videoBitstreamQueue = videoEncoder->bitstream.createOutputQueue(1, false);
+
+    auto stillSource = camRgb->requestOutput(std::make_pair(3840, 2160), dai::ImgFrame::Type::NV12);
+    // Encode full-resolution frames for UVC still-image requests.
+    auto stillEncoder = pipeline.create<dai::node::VideoEncoder>();
+    stillEncoder->setDefaultProfilePreset(4, dai::VideoEncoderProperties::Profile::MJPEG);
+    stillSource->link(stillEncoder->input);
+    stillBitstreamQueue = stillEncoder->bitstream.createOutputQueue(1, false);
 
     // Start pipeline
     pipeline.start();

cpp/uvc/uvc-start.sh

@@ -25,6 +25,8 @@ fi
 MANUF="Luxonis"
 PRODUCT="Luxonis UVC Camera"
 UDC=$(ls /sys/class/udc | head -n1) # will identify the 'first' UDC
+STILL_WIDTH="3840"
+STILL_HEIGHT="2160"
 
 log "=== Detecting platform:"
 log "    product : $PRODUCT"
@@ -66,6 +68,8 @@ remove_uvc_gadget() {
     rm functions/uvc.0/control/class/ss/* 2>/dev/null
     rmdir functions/uvc.0/control/header/* 2>/dev/null
 
+    rmdir functions/uvc.0/control/extensions/* 2>/dev/null
+
     rmdir functions/uvc.0 2>/dev/null
 
     popd >/dev/null
@@ -95,7 +99,7 @@ create_frame() {
     mkdir -p "$wdir"
     echo "$WIDTH" > "$wdir/wWidth"
     echo "$HEIGHT" > "$wdir/wHeight"
-    echo $(( WIDTH * HEIGHT * 2 )) > "$wdir/dwMaxVideoFrameBufferSize"
+    echo $(( STILL_WIDTH * STILL_HEIGHT * 2 )) > "$wdir/dwMaxVideoFrameBufferSize"
     cat <<EOF > "$wdir/dwFrameInterval"
 333333
 EOF
@@ -113,6 +117,9 @@ create_uvc() {
     pushd "$GADGET/g1" >/dev/null
     mkdir "functions/$FUNCTION"
 
+    # write to fule function_name PRODUCT var
+    echo "Luxonis UVC Camera" > "functions/$FUNCTION/function_name"
+
     # create_frame "$FUNCTION" 640 360 uncompressed u
     # create_frame "$FUNCTION" 1280 720 uncompressed u
     # create_frame "$FUNCTION" 320 180 uncompressed u
@@ -121,6 +128,14 @@ create_uvc() {
     # create_frame "$FUNCTION" 640 360 mjpeg m
 
     mkdir "functions/$FUNCTION/streaming/header/h"
+    if [ -w "functions/$FUNCTION/streaming/header/h/still_width" ] && \
+       [ -w "functions/$FUNCTION/streaming/header/h/still_height" ]; then
+        echo "$STILL_WIDTH" > "functions/$FUNCTION/streaming/header/h/still_width"
+        echo "$STILL_HEIGHT" > "functions/$FUNCTION/streaming/header/h/still_height"
+    else
+        log "    Still frame configfs attributes not present, using kernel defaults"
+    fi
+
     cd "functions/$FUNCTION/streaming/header/h"
     # ln -s ../../uncompressed/u
     ln -s ../../mjpeg/m