命令： gst-launch udpsrc port = 5000 返回：错误：无法构造管道：没有元素“ udpsrc” 。
命令： gst-launch-1.0 udpsrc uri = udp：//239.194.0.177：1026 不会，并且（正确地）执行正确。
第一个命令来自许多流媒体教程，例如this one。
第二个命令取自here。只是为了证明udpsrc存在。
他们被削减到令人讨厌的部分。
我拥有gstreamer1.0的所有内容-最新（适用于Ubuntu 16.04.6）：
gstreamer1.0-clutter-3.0 is already the newest version (3.0.18-1).
gstreamer1.0-clutter is already the newest version (2.0.18-1).
gstreamer1.0-crystalhd is already the newest version (1:0.0~git20110715.fdd2f19-11build1).
gstreamer1.0-dvswitch is already the newest version (0.1.1-1).
gstreamer1.0-espeak is already the newest version (0.4.0-1).
gstreamer1.0-fluendo-mp3 is already the newest version (0.10.32.debian-1).
gstreamer1.0-nice is already the newest version (0.1.13-0ubuntu2).
gstreamer1.0-pocketsphinx is already the newest version (0.8.0+real5prealpha-1ubuntu2).
gstreamer1.0-alsa is already the newest version (1.8.3-1ubuntu0.3).
gstreamer1.0-doc is already the newest version (1.8.3-1~ubuntu0.1).
gstreamer1.0-plugins-base is already the newest version (1.8.3-1ubuntu0.3).
gstreamer1.0-plugins-base-apps is already the newest version (1.8.3-1ubuntu0.3).
gstreamer1.0-plugins-base-dbg is already the newest version (1.8.3-1ubuntu0.3).
gstreamer1.0-plugins-base-doc is already the newest version (1.8.3-1ubuntu0.3).
gstreamer1.0-plugins-good is already the newest version (1.8.3-1ubuntu0.4).
gstreamer1.0-plugins-good-dbg is already the newest version (1.8.3-1ubuntu0.4).
gstreamer1.0-plugins-good-doc is already the newest version (1.8.3-1ubuntu0.4).
gstreamer1.0-pulseaudio is already the newest version (1.8.3-1ubuntu0.4).
gstreamer1.0-tools is already the newest version (1.8.3-1~ubuntu0.1).
gstreamer1.0-x is already the newest version (1.8.3-1ubuntu0.3).
libgstreamer1.0-0 is already the newest version (1.8.3-1~ubuntu0.1).
libgstreamer1.0-0-dbg is already the newest version (1.8.3-1~ubuntu0.1).
libgstreamer1.0-dev is already the newest version (1.8.3-1~ubuntu0.1).
gstreamer1.0-libav is already the newest version (1.8.3-1ubuntu0.2).
gstreamer1.0-libav-dbg is already the newest version (1.8.3-1ubuntu0.2).
gstreamer1.0-packagekit is already the newest version (0.8.17-4ubuntu6~gcc5.4ubuntu1.4).
gstreamer1.0-plugins-bad is already the newest version (1.8.3-1ubuntu0.2).
gstreamer1.0-plugins-bad-dbg is already the newest version (1.8.3-1ubuntu0.2).
gstreamer1.0-plugins-bad-doc is already the newest version (1.8.3-1ubuntu0.2).
gstreamer1.0-plugins-bad-faad is already the newest version (1.8.3-1ubuntu0.2).
gstreamer1.0-plugins-bad-videoparsers is already the newest version (1.8.3-1ubuntu0.2).
gstreamer1.0-plugins-ugly is already the newest version (1.8.3-1ubuntu0.1).
gstreamer1.0-plugins-ugly-amr is already the newest version (1.8.3-1ubuntu0.1).
gstreamer1.0-plugins-ugly-dbg is already the newest version (1.8.3-1ubuntu0.1).
gstreamer1.0-plugins-ugly-doc is already the newest version (1.8.3-1ubuntu0.1).
gstreamer1.0-vaapi is already the newest version (1.8.3-1~ubuntu0.1).
gstreamer1.0-vaapi-doc is already the newest version (1.8.3-1~ubuntu0.1).
gstreamer1.0-hybris:i386 is already the newest version (1.8.3-1ubuntu0.2).
$ gst-inspect-1.0 udpsrc
Factory Details:
Rank none (0)
Long-name UDP packet receiver
Klass Source/Network
Description Receive data over the network via UDP
Author Wim Taymans <wim@fluendo.com>, Thijs Vermeir <thijs.vermeir@barco.com>
Plugin Details:
Name udp
Description transfer data via UDP
Filename /usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstudp.so
Version 1.8.3
License LGPL
Source module gst-plugins-good
Source release date 2016-08-19
Binary package GStreamer Good Plugins (Ubuntu)
Origin URL https://launchpad.net/distros/ubuntu/+source/gst-plugins-good1.0
GObject
+----GInitiallyUnowned
+----GstObject
+----GstElement
+----GstBaseSrc
+----GstPushSrc
+----GstUDPSrc
Implemented Interfaces:
GstURIHandler
Pad Templates:
SRC template: 'src'
Availability: Always
Capabilities:
ANY
Element Flags:
no flags set
Element Implementation:
Has change_state() function: 0x7f38aa386e10
Element has no clocking capabilities.
URI handling capabilities:
Element can act as source.
Supported URI protocols:
udp
Pads:
SRC: 'src'
Pad Template: 'src'
Element Properties:
name : The name of the object
flags: readable, writable
String. Default: "udpsrc0"
parent : The parent of the object
flags: readable, writable
Object of type "GstObject"
blocksize : Size in bytes to read per buffer (-1 = default)
flags: readable, writable
Unsigned Integer. Range: 0 - 4294967295 Default: 4096
num-buffers : Number of buffers to output before sending EOS (-1 = unlimited)
flags: readable, writable
Integer. Range: -1 - 2147483647 Default: -1
typefind : Run typefind before negotiating
flags: readable, writable
Boolean. Default: false
do-timestamp : Apply current stream time to buffers
flags: readable, writable
Boolean. Default: true
port : The port to receive the packets from, 0=allocate
flags: readable, writable
Integer. Range: 0 - 65535 Default: 5004
multicast-group : The Address of multicast group to join. (DEPRECATED: Use address property instead)
flags: readable, writable, deprecated
String. Default: "0.0.0.0"
multicast-iface : The network interface on which to join the multicast group
flags: readable, writable
String. Default: null
uri : URI in the form of udp://multicast_group:port
flags: readable, writable
String. Default: "udp://0.0.0.0:5004"
caps : The caps of the source pad
flags: readable, writable
Caps (NULL)
socket : Socket to use for UDP reception. (NULL == allocate)
flags: readable, writable
Object of type "GSocket"
buffer-size : Size of the kernel receive buffer in bytes, 0=default
flags: readable, writable
Integer. Range: 0 - 2147483647 Default: 0
timeout : Post a message after timeout nanoseconds (0 = disabled)
flags: readable, writable
Unsigned Integer64. Range: 0 - 18446744073709551615 Default: 0
skip-first-bytes : number of bytes to skip for each udp packet
flags: readable, writable
Integer. Range: 0 - 2147483647 Default: 0
close-socket : Close socket if passed as property on state change
flags: readable, writable
Boolean. Default: true
used-socket : Socket currently in use for UDP reception. (NULL = no socket)
flags: readable
Object of type "GSocket"
auto-multicast : Automatically join/leave multicast groups
flags: readable, writable
Boolean. Default: true
reuse : Enable reuse of the port
flags: readable, writable
Boolean. Default: true
address : Address to receive packets for. This is equivalent to the multicast-group property for now
flags: readable, writable
String. Default: "0.0.0.0"
loop : Used for setting the multicast loop parameter. TRUE = enable, FALSE = disable
flags: readable, writable
Boolean. Default: true
什么鬼？
或者，如果“不清楚我要问的是”：我需要做什么/重新排序/调整/重新配置/重新编译/等以接收来自端口5000的流？我见过的大多数示例都以“ gst-launch udpsrc port = ...”开头。
答案 0 :(得分：1)
在第一个命令中，您使用gst-launch，但是在第二个gst-launch-1.0中，这就是问题的原因。您应该始终使用gst-launch-1.0。 gst-launch与GStreamer 0.1相关
答案 1 :(得分：0)
我今天也有此错误，但原因有所不同。我发布此答案是为了以防其他人碰巧遇到它。
事实证明，我没有安装所有的GStreamer开发包，特别是 gstreamer-1.0-msvc-x86_64-1.16.0.msi （应该在Windows机器上注意）。安装完该文件后，GStreamer能够找到udpsrc。