I'm trying to put opencv images into a gstreamer rtsp server in python. I have some issue writing in the mediafactory, I'm new to gst-rtsp-server ancd there's little documentation so I don't know exactly if I'm using the right approach. I'm using a thread to start the MainLoop and I'm using the main thread to create a buffer to push in the appsrc element of the mediafactory pipeline. Am I using the right approach to obtain my objective? Can anyone help me? My code is below:
from threading import Thread
from time import clock
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.launch_string = 'appsrc ! video/x-raw,width=320,height=240,framerate=30/1 ' \
'! videoconvert ! x264enc speed-preset=ultrafast tune=zerolatency ' \
'! rtph264pay config-interval=1 name=pay0 pt=96'
self.pipeline = Gst.parse_launch(self.launch_string)
self.appsrc = self.pipeline.get_child_by_index(4)
def do_create_element(self, url):
return self.pipeline
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()
th = Thread(target=loop.run)
th.start()
print('Thread started')
cap = cv2.VideoCapture(0)
print(cap.isOpened())
frame_number = 0
fps = 30
duration = 1 / fps
timestamp = clock()
while cap.isOpened():
ret, frame = cap.read()
if ret:
print('Writing buffer')
data = frame.tostring()
buf = Gst.Buffer.new_allocate(None, len(data), None)
buf.fill(0, data)
buf.duration = fps
timestamp = clock() - timestamp
buf.pts = buf.dts = int(timestamp)
buf.offset = frame_number
frame_number += 1
retval = server.factory.appsrc.emit('push-buffer', buf)
print(retval)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
By the way I tried to copy the buffer creation from opencv source code but I'm not sure I correctly trandlated the c++ code in python.
I found the solution, lots of stuff was missing.
Here's the code for anyone who's facing the same problem or has a somewhat similar one.
#!/usr/bin/env python3
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.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()