| Top |  |
 |
 |
 |
Properties
| GstCaps * | caps | Read / Write |
| gchar * | multicast-group | Read / Write |
| gint | port | Read / Write |
| gchar * | uri | Read / Write |
| gint | buffer-size | Read / Write |
| guint64 | timeout | Read / Write |
| gint | skip-first-bytes | Read / Write |
| gboolean | auto-multicast | Read / Write |
| gchar * | multicast-iface | Read / Write |
| gboolean | reuse | Read / Write |
| gboolean | close-socket | Read / Write |
| GSocket * | socket | Read / Write |
| GSocket * | used-socket | Read |
| gchar * | address | Read / Write |
| gboolean | loop | Read / Write |
| gboolean | retrieve-sender-address | Read / Write |
Object Hierarchy
GObject ╰── GInitiallyUnowned ╰── GstObject ╰── GstElement ╰── GstBaseSrc ╰── GstPushSrc ╰── GstUDPSrc
Description
udpsrc is a network source that reads UDP packets from the network. It can be combined with RTP depayloaders to implement RTP streaming.
The udpsrc element supports automatic port allocation by setting the “port” property to 0. After setting the udpsrc to PAUSED, the allocated port can be obtained by reading the port property.
udpsrc can read from multicast groups by setting the “multicast-group” property to the IP address of the multicast group.
Alternatively one can provide a custom socket to udpsrc with the “socket” property, udpsrc will then not allocate a socket itself but use the provided one.
The “caps” property is mainly used to give a type to the UDP packet so that they can be autoplugged in GStreamer pipelines. This is very useful for RTP implementations where the contents of the UDP packets is transfered out-of-bounds using SDP or other means.
The “buffer-size” property is used to change the default kernel buffersizes used for receiving packets. The buffer size may be increased for high-volume connections, or may be decreased to limit the possible backlog of incoming data. The system places an absolute limit on these values, on Linux, for example, the default buffer size is typically 50K and can be increased to maximally 100K.
The “skip-first-bytes” property is used to strip off an arbitrary number of bytes from the start of the raw udp packet and can be used to strip off proprietary header, for example.
The udpsrc is always a live source. It does however not provide a GstClock, this is left for downstream elements such as an RTP session manager or demuxer (such as an MPEG demuxer). As with all live sources, the captured buffers will have their timestamp set to the current running time of the pipeline.
udpsrc implements a GstURIHandler interface that handles udp://host:port type URIs.
If the “timeout” property is set to a value bigger than 0, udpsrc will generate an element message named
"GstUDPSrcTimeout"if no data was recieved in the given timeout. The message's structure contains one field:
guint64
"timeout": the timeout in microseconds that expired when waiting for data.
The message is typically used to detect that no UDP arrives in the receiver because it is blocked by a firewall.
A custom file descriptor can be configured with the “socket” property. The socket will be closed when setting the element to READY by default. This behaviour can be overriden with the “close-socket” property, in which case the application is responsible for closing the file descriptor.
Examples
1 |
gst-launch-1.0 -v udpsrc ! fakesink dump=1 |
1 |
gst-launch-1.0 -v audiotestsrc ! udpsink |
1 |
gst-launch-1.0 -v udpsrc port=0 ! fakesink |
Synopsis
Element Information
plugin |
udp |
author |
Wim Taymans <wim@fluendo.com>, Thijs Vermeir <thijs.vermeir@barco.com> |
class |
Source/Network |
Property Details
The “multicast-group” property
“multicast-group” gchar *
The Address of multicast group to join. (DEPRECATED: Use address property instead).
Flags: Read / Write
Default value: "0.0.0.0"
The “port” property
“port” gint
The port to receive the packets from, 0=allocate.
Flags: Read / Write
Allowed values: [0,65535]
Default value: 5004
The “uri” property
“uri” gchar *
URI in the form of udp://multicast_group:port.
Flags: Read / Write
Default value: "udp://0.0.0.0:5004"
The “buffer-size” property
“buffer-size” gint
Size of the kernel receive buffer in bytes, 0=default.
Flags: Read / Write
Allowed values: >= 0
Default value: 0
The “timeout” property
“timeout” guint64
Post a message after timeout nanoseconds (0 = disabled).
Flags: Read / Write
Default value: 0
The “skip-first-bytes” property
“skip-first-bytes” gint
number of bytes to skip for each udp packet.
Flags: Read / Write
Allowed values: >= 0
Default value: 0
The “auto-multicast” property
“auto-multicast” gboolean
Automatically join/leave multicast groups.
Flags: Read / Write
Default value: TRUE
The “multicast-iface” property
“multicast-iface” gchar *
The network interface on which to join the multicast group.This allows multiple interfaces seperated by comma. ("eth0,eth1").
Flags: Read / Write
Default value: NULL
The “reuse” property
“reuse” gboolean
Enable reuse of the port.
Flags: Read / Write
Default value: TRUE
The “close-socket” property
“close-socket” gboolean
Close socket if passed as property on state change.
Flags: Read / Write
Default value: TRUE
The “socket” property
“socket” GSocket *
Socket to use for UDP reception. (NULL == allocate).
Flags: Read / Write
The “used-socket” property
“used-socket” GSocket *
Socket currently in use for UDP reception. (NULL = no socket).
Flags: Read
The “address” property
“address” gchar *
Address to receive packets for. This is equivalent to the multicast-group property for now.
Flags: Read / Write
Default value: "0.0.0.0"
The “loop” property
“loop” gboolean
Used for setting the multicast loop parameter. TRUE = enable, FALSE = disable.
Flags: Read / Write
Default value: TRUE
The “retrieve-sender-address” property
“retrieve-sender-address” gboolean
Whether to retrieve the sender address and add it to buffers as meta. Disabling this might result in minor performance improvements in certain scenarios.
Flags: Read / Write
Default value: TRUE