3.18. Gen2 彩色相机编码与MobilenetSSD模型

这个例子显示了如何配置 depthai 视频编码器在 h.265格式编码 RGB 摄像机输入在30FPS 的全高清分辨率，并传输编码的视频通过 XLINK 到主机，保存到磁盘作为视频文件。同时，mobileetv2ssd 网络在用于编码的同一个 RGB 摄像头的帧上运行。

按 Ctrl + c 将停止程序，然后使用 ffmpeg 将其转换为 mp4，使其可播放。请注意，ffmpeg 需要安装并运行才能成功转换为 mp4。

注意，此示例将编码视频保存到主机存储中。因此，如果您让它们一直运行，您可以填满您的主机上的存储空间。

3.18.1. 演示

3.18.2. 设置

请运行以下命令来安装所需的依赖项

Warning

说明：此处安装的是第二代depthai库

python3 -m pip install --extra-index-url https://artifacts.luxonis.com/artifactory/luxonis-python-snapshot-local/ depthai==0.0.2.1+c9a19df719cb668e438d6eafd193cdf60a0d9354 numpy==1.19.5 opencv-python==4.5.1.48

有关更多信息，请参阅 Python API 安装指南

这个示例还需要 mobileenetsdd blob ( mobilenet.blob 文件 )才能工作——您可以从这里下载它。

3.18.3. 源代码

可以在 GitHub 上找到。国内用户也可以在 gitee 上找到。

from pathlib import Path
import sys
import cv2
import depthai as dai
import numpy as np

# 首先获取模型
mobilenet_path = str((Path(__file__).parent / Path('models/mobilenet.blob')).resolve().absolute())
if len(sys.argv) > 1:
    mobilenet_path = sys.argv[1]

# 开始定义管道
pipeline = dai.Pipeline()

cam = pipeline.createColorCamera()
cam.setBoardSocket(dai.CameraBoardSocket.RGB)
cam.setResolution(dai.ColorCameraProperties.SensorResolution.THE_1080_P)
cam.setPreviewSize(300, 300)
cam.setInterleaved(False)

videoEncoder = pipeline.createVideoEncoder()
videoEncoder.setDefaultProfilePreset(1920, 1080, 30, dai.VideoEncoderProperties.Profile.H265_MAIN)
cam.video.link(videoEncoder.input)

detection_nn = pipeline.createNeuralNetwork()
detection_nn.setBlobPath(mobilenet_path)
cam.preview.link(detection_nn.input)

videoOut = pipeline.createXLinkOut()
videoOut.setStreamName('h265')
videoEncoder.bitstream.link(videoOut.input)

xout_rgb = pipeline.createXLinkOut()
xout_rgb.setStreamName("rgb")
cam.preview.link(xout_rgb.input)

xout_nn = pipeline.createXLinkOut()
xout_nn.setStreamName("nn")
detection_nn.out.link(xout_nn.input)

# MobilenetSSD标签文本
texts = ["background", "aeroplane", "bicycle", "bird", "boat", "bottle", "bus", "car", "cat", "chair", "cow",
         "diningtable", "dog", "horse", "motorbike", "person", "pottedplant", "sheep", "sofa", "train", "tvmonitor"]

with dai.Device(pipeline) as device, open('video.h265', 'wb') as videoFile:
    device.startPipeline()

    queue_size = 8
    q_rgb = device.getOutputQueue("rgb", queue_size)
    q_nn = device.getOutputQueue("nn", queue_size)
    q_rgb_enc = device.getOutputQueue('h265', maxSize=30, blocking=True)

    frame = None
    bboxes = []
    labels = []
    confidences = []


    def frame_norm(frame, bbox):
        norm_vals = np.full(len(bbox), frame.shape[0])
        norm_vals[::2] = frame.shape[1]
        return (np.clip(np.array(bbox), 0, 1) * norm_vals).astype(int)


    while True:
        in_rgb = q_rgb.tryGet()
        in_nn = q_nn.tryGet()

        while q_rgb_enc.has():
            q_rgb_enc.get().getData().tofile(videoFile)

        if in_rgb is not None:
            # 如果来自RGB相机的数据不为空，则将1D数据转换为HxWxC帧
            shape = (3, in_rgb.getHeight(), in_rgb.getWidth())
            frame = in_rgb.getData().reshape(shape).transpose(1, 2, 0).astype(np.uint8)
            frame = np.ascontiguousarray(frame)

        if in_nn is not None:
            bboxes = np.array(in_nn.getFirstLayerFp16())
            bboxes = bboxes.reshape((bboxes.size // 7, 7))
            bboxes = bboxes[bboxes[:, 2] > 0.5]
            # 剪切bbox和标签
            labels = bboxes[:, 1].astype(int)
            confidences = bboxes[:, 2]
            bboxes = bboxes[:, 3:7]

        if frame is not None:
            for raw_bbox, label, conf in zip(bboxes, labels, confidences):
                bbox = frame_norm(frame, raw_bbox)
                cv2.rectangle(frame, (bbox[0], bbox[1]), (bbox[2], bbox[3]), (255, 0, 0), 2)
                cv2.putText(frame, texts[label], (bbox[0] + 10, bbox[1] + 20), cv2.FONT_HERSHEY_TRIPLEX, 0.5, 255)
                cv2.putText(frame, f"{int(conf * 100)}%", (bbox[0] + 10, bbox[1] + 40), cv2.FONT_HERSHEY_TRIPLEX, 0.5, 255)
            cv2.imshow("rgb", frame)

        if cv2.waitKey(1) == ord('q'):
            break

print("To view the encoded data, convert the stream file (.h265) into a video file (.mp4) using a command below:")
print("ffmpeg -framerate 30 -i video.h265 -c copy video.mp4")