如何使用GStreamer和Python进行RTSP流媒体播放？ [英] How to RTSP stream a video using Gstreamer and Python?

问题描述

我有一段代码，它当前获取一个视频，并使用用于Python的GStreamer绑定在屏幕上显示它。我可以在播放器打开时点击"前进"按钮来搜索视频，这对我来说是一个重要的功能，因此我不想使用解析来编写管道并将其发送到GST-Launch。

我现在想要做的是不仅将这个视频流到一个新打开的窗口，而且(或者只有在我不能两者兼有的情况下)通过RTSP在VLC甚至通过局域网的另一个客户端打开它。有什么办法可以做到这一点吗？

很抱歉，代码太长了，但下面是：

import sys, os, time
import gi
gi.require_version('Gst', '1.0')
from gi.repository import Gst, GObject, Gtk
from gi.repository import GdkX11, GstVideo

class GTK_Main(object):

    def __init__(self):
        window = Gtk.Window(Gtk.WindowType.TOPLEVEL)
        window.set_title("Vorbis-Player")
        window.set_default_size(500, -1)
        window.connect("destroy", Gtk.main_quit, "WM destroy")
        vbox = Gtk.VBox()
        window.add(vbox)
        self.entry = Gtk.Entry()
        vbox.pack_start(self.entry, False, False, 0)
        hbox = Gtk.HBox()
        vbox.add(hbox)
        buttonbox = Gtk.HButtonBox()
        hbox.pack_start(buttonbox, False, False, 0)
        rewind_button = Gtk.Button("Rewind")
        rewind_button.connect("clicked", self.rewind_callback)
        buttonbox.add(rewind_button)
        self.button = Gtk.Button("Start")
        self.button.connect("clicked", self.start_stop)
        buttonbox.add(self.button)
        forward_button = Gtk.Button("Forward")
        forward_button.connect("clicked", self.forward_callback)
        buttonbox.add(forward_button)
        self.time_label = Gtk.Label()
        self.time_label.set_text("00:00 / 00:00")
        hbox.add(self.time_label)
        window.show_all()

        self.player = Gst.ElementFactory.make("playbin", "player")
        bus = self.player.get_bus()
        bus.add_signal_watch()
        bus.enable_sync_message_emission()
        bus.connect("message", self.on_message)
        bus.connect("sync-message::element", self.on_sync_message)

    def start_stop(self, w):
        if self.button.get_label() == "Start":
            filepath = self.entry.get_text().strip()
            if os.path.isfile(filepath):
                filepath = os.path.realpath(filepath)
                self.butto

    n.set_label("Stop")
                    self.player.set_property("uri", "file://" + filepath)
                    self.player.set_state(Gst.State.PLAYING)
                    time.sleep(1)
                    self.forward_callback(60)
                else:
                    self.player.set_state(Gst.State.NULL)
                    self.button.set_label("Start")

        def on_message(self, bus, message):
            t = message.type
            if t == Gst.MessageType.EOS:
                self.player.set_state(Gst.State.NULL)
                self.button.set_label("Start")
            elif t == Gst.MessageType.ERROR:
                self.player.set_state(Gst.State.NULL)
                err, debug = message.parse_error()
                print ("Error: %s" % err, debug)
                self.button.set_label("Start")

        def on_sync_message(self, bus, message):
            if message.get_structure().get_name() == 'prepare-window-handle':
                imagesink = message.src
                imagesink.set_property("force-aspect-ratio", True)
                imagesink.set_window_handle(self.movie_window.get_property('window').get_xid())

        def rewind_callback(self, w):
            rc, pos_int = self.player.query_position(Gst.Format.TIME)
            seek_ns = pos_int - 10 * 1000000000
            if seek_ns < 0:
                seek_ns = 0
            print ("Backward: %d ns -> %d ns" % (pos_int, seek_ns))
            self.player.seek_simple(Gst.Format.TIME, Gst.SeekFlags.FLUSH, seek_ns)

        def forward_callback(self, w):
            rc, pos_int = self.player.query_position(Gst.Format.TIME)
            if type(w) == int:
                seek_ns = w * 1000000000
            else:
                seek_ns = pos_int + 10 * 1000000000
            print ("Forward: %d ns -> %d ns" % (pos_int, seek_ns))
            self.player.seek_simple(Gst.Format.TIME, Gst.SeekFlags.FLUSH, seek_ns)

        def convert_ns(self, t):
            # This method was submitted by Sam Mason.
            # It's much shorter than the original one.
            s,ns = divmod(t, 1000000000)
            m,s = divmod(s, 60)

            if m < 60:
                return "%02i:%02i" %(m,s)
            else:
                h,m = divmod(m, 60)
                return "%i:%02i:%02i" %(h,m,s)


    GObject.threads_init()
    Gst.init(None)        
    GTK_Main()
    Gtk.main()

我在this教程中找到了此代码。

推荐答案

所以，我最终设法使提供的链接起作用。我的问题是视频的宽度和高度，它必须具有与您想要播放的视频完全相同的值，可能与OpenCV帧传递有关...此外，由于使用链接的解决方案中的网络摄像头而被设置为True的"is-live"属性必须设置为False(或根本不使用，因为这是默认值)，否则视频将在黑屏中以一定的延迟开始。代码最终为：

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("path/to/video")
        self.number_frames = 0
        self.fps = 8
        self.duration = 1 / self.fps * Gst.SECOND  # duration of a frame in nanoseconds
        self.launch_string = 'appsrc name=source block=true format=GST_FORMAT_TIME ' 
                             'caps=video/x-raw,format=BGR,width=1280,height=720,framerate={}/1 ' 
                             '! videoconvert ! video/x-raw,format=I420 ' 
                             '! x264enc speed-preset=ultrafast tune=zerolatency ! queue ' 
                             '! rtph264pay config-interval=1 name=pay0 pt=96 '.format(self.fps)
        # streams to gst-launch-1.0 rtspsrc location=rtsp://localhost:8554/test latency=50 ! decodebin ! autovideosink

    def on_need_data(self, src, lenght):
        if self.cap.isOpened():
            ret, frame = self.cap.read()
            if ret:
                data = frame.tostring()
                #print(data)
                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()

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