Question

我的目标是从rtsp服务器读取帧，对帧进行一些opencv操纵，然后将操纵后的帧写入新的rtsp服务器。

我基于Write in Gstreamer pipeline from opencv in python尝试了以下操作，但是我无法弄清楚创建rtsp服务器应使用的适当的gst-launch-1.0参数。任何人都可以协助gst-launch-1.0的适当论点吗？我尝试过的那些卡在了“管道预卷”中

import cv2

cap = cv2.VideoCapture("rtsp://....")

framerate = 25.0

out = cv2.VideoWriter('appsrc ! videoconvert ! '
  'x264enc noise-reduction=10000 speed-preset=ultrafast 
   tune=zerolatency ! '
  'rtph264pay config-interval=1 pt=96 !'
  'tcpserversink host=192.168.1.27 port=5000 sync=false',
  0, framerate, (640, 480))


counter = 0
while cap.isOpened():
  ret, frame = cap.read()
  if ret:
    out.write(frame)

    if cv2.waitKey(1) & 0xFF == ord('q'):
      break
  else:
    break

cap.release()
out.release()

我还尝试了另一种基于Write opencv frames into gstreamer rtsp server pipeline的解决方案

import cv2
import gi 

gi.require_version('Gst', '1.0')
gi.require_version('GstRtspServer', '1.0') 
from gi.repository import Gst, GstRtspServer, GObject

class SensorFactory(GstRtspServer.RTSPMediaFactory):
  def __init__(self, **properties): 
    super(SensorFactory, self).__init__(**properties) 
    #self.cap = cv2.VideoCapture(0)
    self.cap = cv2.VideoCapture("rtsp://....")
    self.number_frames = 0 
    self.fps = 30
    self.duration = 1 / self.fps * Gst.SECOND  # duration of a frame in nanoseconds 
    self.launch_string = 'appsrc name=source is-live=true block=true format=GST_FORMAT_TIME ' \
                         'caps=video/x-raw,format=BGR,width=640,height=480,framerate={}/1 ' \
                         '! videoconvert ! video/x-raw,format=I420 ' \
                         '! x264enc speed-preset=ultrafast tune=zerolatency ' \
                         '! rtph264pay config-interval=1 name=pay0 pt=96'.format(self.fps)

  def on_need_data(self, src, lenght):
    if self.cap.isOpened():
      ret, frame = self.cap.read()
      if ret:
        data = frame.tostring() 
        buf = Gst.Buffer.new_allocate(None, len(data), None)
        buf.fill(0, data)
        buf.duration = self.duration
        timestamp = self.number_frames * self.duration
        buf.pts = buf.dts = int(timestamp)
        buf.offset = timestamp
        self.number_frames += 1
        retval = src.emit('push-buffer', buf) 

        print('pushed buffer, frame {}, duration {} ns, durations {} s'.format(self.number_frames, self.duration, self.duration / Gst.SECOND)) 

        if retval != Gst.FlowReturn.OK: 
          print(retval) 

  def do_create_element(self, url): 
    return Gst.parse_launch(self.launch_string) 

  def do_configure(self, rtsp_media): 
    self.number_frames = 0 
    appsrc = rtsp_media.get_element().get_child_by_name('source') 
    appsrc.connect('need-data', self.on_need_data) 


class GstServer(GstRtspServer.RTSPServer): 
  def __init__(self, **properties): 
    super(GstServer, self).__init__(**properties) 
    self.factory = SensorFactory() 
    self.factory.set_shared(True) 
    self.get_mount_points().add_factory("/test", self.factory) 
    self.attach(None) 


GObject.threads_init() 
Gst.init(None) 

server = GstServer() 

loop = GObject.MainLoop() 
loop.run()

此解决方案自行生成rtsp服务器并流式传输到它。我可以在VLC中打开生成的rtsp流，但它会一直显示第一帧，并且不会使用新帧进行更新。谁知道为什么？

我正在寻找任何解决方案，这些解决方案将使我能够以低延迟将rtsp服务器中的帧读取为opencv格式，处理帧并将帧输出到新的rtsp服务器（我也需要创建）。如果存在更好的解决方案，则不必基于gstreamer。

我正在将Ubuntu 16.04与python2.7和opencv 3.4.1结合使用

在python中基于opencv图像创建rtsp流

0 个答案: