multifdsink

multifdsink — Send data to multiple file descriptors

Synopsis




            GstMultiFdSink;
enum        GstRecoverPolicy;
enum        GstSyncMethod;
enum        GstClientStatus;

Object Hierarchy


  GObject
   +----GstObject
         +----GstElement
               +----GstBaseSink
                     +----GstMultiFdSink
                           +----GstTCPServerSink

Properties


  "buffers-max"          gint                  : Read / Write
  "buffers-queued"       guint                 : Read
  "buffers-soft-max"     gint                  : Read / Write
  "bytes-served"         guint64               : Read
  "bytes-to-serve"       guint64               : Read
  "mode"                 GstFDSetMode          : Read / Write
  "protocol"             GstTCPProtocol        : Read / Write
  "recover-policy"       GstRecoverPolicy      : Read / Write
  "sync-clients"         gboolean              : Read / Write
  "sync-method"          GstSyncMethod         : Read / Write
  "timeout"              guint64               : Read / Write
  "buffers-min"          gint                  : Read / Write
  "burst-unit"           GstTCPUnitType        : Read / Write
  "burst-value"          guint64               : Read / Write
  "bytes-min"            gint                  : Read / Write
  "time-min"             gint64                : Read / Write
  "unit-type"            GstTCPUnitType        : Read / Write
  "units-max"            gint64                : Read / Write
  "units-soft-max"       gint64                : Read / Write

Signals


"add"       void        user_function      (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gpointer        user_data)           : Run last
"clear"     void        user_function      (GstMultiFdSink *gstmultifdsink,
                                            gpointer        user_data)           : Run last
"client-added"
            void        user_function      (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gpointer        user_data)           : Run last
"client-removed"
            void        user_function      (GstMultiFdSink  *gstmultifdsink,
                                            gint             fd,
                                            GstClientStatus *status,
                                            gpointer         user_data)           : Run last
"get-stats" GValueArray*user_function      (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gpointer        user_data)           : Run last
"remove"    void        user_function      (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gpointer        user_data)           : Run last
"client-fd-removed"
            void        user_function      (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gpointer        user_data)           : Run last
"add-full"  void        user_function      (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gboolean        keyframe,
                                            GstTCPUnitType *unit_type_min,
                                            guint64         value_min,
                                            GstTCPUnitType *unit_type_max,
                                            guint64         value_max,
                                            gpointer        user_data)           : Run last

Description

This plugin writes incoming data to a set of file descriptors. The file descriptors can be added to multifdsink by emitting the "add" signal. For each descriptor added, the "client-added" signal will be called.

As of version 0.10.8, a client can also be added with the "add-full" signal that allows for more control over what and how much data a client initially receives.

Clients can be removed from multifdsink by emitting the "remove" signal. For each descriptor removed, the "client-removed" signal will be called. The "client-removed" signal can also be fired when multifdsink decides that a client is not active anymore or, depending on the value of the "recover-policy" property, if the client is reading too slowly. In all cases, multifdsink will never close a file descriptor itself. The user of multifdsink is responsible for closing all file descriptors. This can for example be done in response to the "client-fd-removed" signal. Note that multifdsink still has a reference to the file descriptor when the "client-removed" signal is emitted, so that "get-stats" can be performed on the descriptor; it is therefore not safe to close the file descriptor in the "client-removed" signal handler, and you should use the "client-fd-removed" signal to safely close the fd.

Multifdsink internally keeps a queue of the incoming buffers and uses a separate thread to send the buffers to the clients. This ensures that no client write can block the pipeline and that clients can read with different speeds.

When adding a client to multifdsink, the "sync-method" property will define which buffer in the queued buffers will be sent first to the client. Clients can be sent the most recent buffer (which might not be decodable by the client if it is not a keyframe), the next keyframe received in multifdsink (which can take some time depending on the keyframe rate), or the last received keyframe (which will cause a simple burst-on-connect). Multifdsink will always keep at least one keyframe in its internal buffers when the sync-mode is set to latest-keyframe.

As of version 0.10.8, there are additional values for the sync-method property to allow finer control over burst-on-connect behaviour. By selecting the 'burst' method a minimum burst size can be chosen, 'burst-keyframe' additionally requires that the burst begin with a keyframe, and 'burst-with-keyframe' attempts to burst beginning with a keyframe, but will prefer a minimum burst size even if it requires not starting with a keyframe.

Multifdsink can be instructed to keep at least a minimum amount of data expressed in time or byte units in its internal queues with the the "time-min" and "bytes-min" properties respectively. These properties are useful if the application adds clients with the "add-full" signal to make sure that a burst connect can actually be honored.

When streaming data, clients are allowed to read at a different rate than the rate at which multifdsink receives data. If the client is reading too fast, no data will be send to the client until multifdsink receives more data. If the client, however, reads too slowly, data for that client will be queued up in multifdsink. Two properties control the amount of data (buffers) that is queued in multifdsink: "buffers-max" and "buffers-soft-max". A client that falls behind by "buffers-max" is removed from multifdsink forcibly.

A client with a lag of at least "buffers-soft-max" enters the recovery procedure which is controlled with the "recover-policy" property. A recover policy of NONE will do nothing, RESYNC_LATEST will send the most recently received buffer as the next buffer for the client, RESYNC_SOFT_LIMIT positions the client to the soft limit in the buffer queue and RESYNC_KEYFRAME positions the client at the most recent keyframe in the buffer queue.

multifdsink will by default synchronize on the clock before serving the buffers to the clients. This behaviour can be disabled by setting the sync property to FALSE. Multifdsink will by default not do QoS and will never drop late buffers.

Last reviewed on 2006-09-12 (0.10.10)

Element Information

plugin tcp tcp tcpauthorThomas Vander Stichele <thomas at apestaart dot org>, Wim Taymans <wim@fluendo.com>Thomas Vander Stichele <thomas at apestaart dot org>, Wim Taymans <wim@fluendo.com>classSink/NetworkSink/Network
plugin tcp
author Thomas Vander Stichele <thomas at apestaart dot org>, Wim Taymans <wim@fluendo.com>
class Sink/Network

Details

GstMultiFdSink

typedef struct _GstMultiFdSink GstMultiFdSink;

The multifdsink object structure.


enum GstRecoverPolicy

typedef enum
{
  GST_RECOVER_POLICY_NONE,
  GST_RECOVER_POLICY_RESYNC_LATEST,
  GST_RECOVER_POLICY_RESYNC_SOFT_LIMIT,
  GST_RECOVER_POLICY_RESYNC_KEYFRAME,
} GstRecoverPolicy;

Possible values for the recovery procedure to use when a client consumes data too slow and has a backlag of more that soft-limit buffers.

GST_RECOVER_POLICY_NONEGST_RECOVER_POLICY_NONE no recovering is done no recovering is done GST_RECOVER_POLICY_RESYNC_LATESTGST_RECOVER_POLICY_RESYNC_LATEST client is moved to last buffer client is moved to last buffer GST_RECOVER_POLICY_RESYNC_SOFT_LIMITGST_RECOVER_POLICY_RESYNC_SOFT_LIMIT client is moved to the soft limit client is moved to the soft limit GST_RECOVER_POLICY_RESYNC_KEYFRAMEGST_RECOVER_POLICY_RESYNC_KEYFRAME client is moved to latest keyframe client is moved to latest keyframe
GST_RECOVER_POLICY_NONE no recovering is done
GST_RECOVER_POLICY_RESYNC_LATEST client is moved to last buffer
GST_RECOVER_POLICY_RESYNC_SOFT_LIMIT client is moved to the soft limit
GST_RECOVER_POLICY_RESYNC_KEYFRAME client is moved to latest keyframe

enum GstSyncMethod

typedef enum
{
  GST_SYNC_METHOD_LATEST,
  GST_SYNC_METHOD_NEXT_KEYFRAME,
  GST_SYNC_METHOD_LATEST_KEYFRAME,
  GST_SYNC_METHOD_BURST,
  GST_SYNC_METHOD_BURST_KEYFRAME,
  GST_SYNC_METHOD_BURST_WITH_KEYFRAME,
} GstSyncMethod;

This enum defines the selection of the first buffer that is sent to a new client.

GST_SYNC_METHOD_LATESTGST_SYNC_METHOD_LATEST client receives most recent buffer client receives most recent buffer GST_SYNC_METHOD_NEXT_KEYFRAMEGST_SYNC_METHOD_NEXT_KEYFRAME client receives next keyframe client receives next keyframe GST_SYNC_METHOD_LATEST_KEYFRAMEGST_SYNC_METHOD_LATEST_KEYFRAME client receives latest keyframe (burst) client receives latest keyframe (burst) GST_SYNC_METHOD_BURSTGST_SYNC_METHOD_BURST client receives specific amount of data client receives specific amount of data GST_SYNC_METHOD_BURST_KEYFRAMEGST_SYNC_METHOD_BURST_KEYFRAME client receives specific amount of data starting from latest keyframe client receives specific amount of data starting from latest keyframe GST_SYNC_METHOD_BURST_WITH_KEYFRAMEGST_SYNC_METHOD_BURST_WITH_KEYFRAME client receives specific amount of data from a keyframe, or if there is not enough data after the keyframe, starting before the keyframe client receives specific amount of data from a keyframe, or if there is not enough data after the keyframe, starting before the keyframe
GST_SYNC_METHOD_LATEST client receives most recent buffer
GST_SYNC_METHOD_NEXT_KEYFRAME client receives next keyframe
GST_SYNC_METHOD_LATEST_KEYFRAME client receives latest keyframe (burst)
GST_SYNC_METHOD_BURST client receives specific amount of data
GST_SYNC_METHOD_BURST_KEYFRAME client receives specific amount of data starting from latest keyframe
GST_SYNC_METHOD_BURST_WITH_KEYFRAME client receives specific amount of data from a keyframe, or if there is not enough data after the keyframe, starting before the keyframe

enum GstClientStatus

typedef enum
{
  GST_CLIENT_STATUS_OK          = 0,
  GST_CLIENT_STATUS_CLOSED      = 1,
  GST_CLIENT_STATUS_REMOVED     = 2,
  GST_CLIENT_STATUS_SLOW        = 3,
  GST_CLIENT_STATUS_ERROR       = 4,
  GST_CLIENT_STATUS_DUPLICATE   = 5,
} GstClientStatus;

This specifies the reason why a client was removed from multifdsink and is received in the "client-removed" signal.

GST_CLIENT_STATUS_OKGST_CLIENT_STATUS_OK client is ok client is ok GST_CLIENT_STATUS_CLOSEDGST_CLIENT_STATUS_CLOSED client closed the socket client closed the socket GST_CLIENT_STATUS_REMOVEDGST_CLIENT_STATUS_REMOVED client is removed client is removed GST_CLIENT_STATUS_SLOWGST_CLIENT_STATUS_SLOW client is too slow client is too slow GST_CLIENT_STATUS_ERRORGST_CLIENT_STATUS_ERROR client is in error client is in error GST_CLIENT_STATUS_DUPLICATEGST_CLIENT_STATUS_DUPLICATE same client added twice same client added twice
GST_CLIENT_STATUS_OK client is ok
GST_CLIENT_STATUS_CLOSED client closed the socket
GST_CLIENT_STATUS_REMOVED client is removed
GST_CLIENT_STATUS_SLOW client is too slow
GST_CLIENT_STATUS_ERROR client is in error
GST_CLIENT_STATUS_DUPLICATE same client added twice

Property Details

The "buffers-max" property

  "buffers-max"          gint                  : Read / Write

max number of buffers to queue for a client (-1 = no limit).

Allowed values: >= G_MAXULONG

Default value: -1


The "buffers-queued" property

  "buffers-queued"       guint                 : Read

Number of buffers currently queued.

Default value: 0


The "buffers-soft-max" property

  "buffers-soft-max"     gint                  : Read / Write

Recover client when going over this limit (-1 = no limit).

Allowed values: >= G_MAXULONG

Default value: -1


The "bytes-served" property

  "bytes-served"         guint64               : Read

Total number of bytes send to all clients.

Default value: 0


The "bytes-to-serve" property

  "bytes-to-serve"       guint64               : Read

Number of bytes received to serve to clients.

Default value: 0


The "mode" property

  "mode"                 GstFDSetMode          : Read / Write

The mode for selecting activity on the fds.

Default value: Poll


The "protocol" property

  "protocol"             GstTCPProtocol        : Read / Write

The protocol to wrap data in.

Default value: GST_TCP_PROTOCOL_NONE


The "recover-policy" property

  "recover-policy"       GstRecoverPolicy      : Read / Write

How to recover when client reaches the soft max.

Default value: Do not try to recover


The "sync-clients" property

  "sync-clients"         gboolean              : Read / Write

(DEPRECATED) Sync clients to a keyframe.

Default value: FALSE


The "sync-method" property

  "sync-method"          GstSyncMethod         : Read / Write

How to sync new clients to the stream.

Default value: Serve starting from the latest buffer


The "timeout" property

  "timeout"              guint64               : Read / Write

Maximum inactivity timeout in nanoseconds for a client (0 = no limit).

Default value: 0


The "buffers-min" property

  "buffers-min"          gint                  : Read / Write

min number of buffers to queue (-1 = as few as possible).

Allowed values: >= G_MAXULONG

Default value: -1


The "burst-unit" property

  "burst-unit"           GstTCPUnitType        : Read / Write

The format of the burst units (when sync-method is burst[[-with]-keyframe]).

Default value: Undefined


The "burst-value" property

  "burst-value"          guint64               : Read / Write

The amount of burst expressed in burst-unit.

Default value: 0


The "bytes-min" property

  "bytes-min"            gint                  : Read / Write

min number of bytes to queue (-1 = as little as possible).

Allowed values: >= G_MAXULONG

Default value: -1


The "time-min" property

  "time-min"             gint64                : Read / Write

min number of time to queue (-1 = as little as possible).

Allowed values: >= G_MAXULONG

Default value: -1


The "unit-type" property

  "unit-type"            GstTCPUnitType        : Read / Write

The unit to measure the max/soft-max/queued properties.

Default value: Buffers


The "units-max" property

  "units-max"            gint64                : Read / Write

max number of units to queue (-1 = no limit).

Allowed values: >= G_MAXULONG

Default value: -1


The "units-soft-max" property

  "units-soft-max"       gint64                : Read / Write

Recover client when going over this limit (-1 = no limit).

Allowed values: >= G_MAXULONG

Default value: -1

Signal Details

The "add" signal

void        user_function                  (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gpointer        user_data)           : Run last

Hand the given open file descriptor to multifdsink to write to.

gstmultifdsink :gstmultifdsink the multifdsink element to emit this signal on the multifdsink element to emit this signal on fd :fd the file descriptor to add to multifdsink the file descriptor to add to multifdsink user_data :user_datauser data set when the signal handler was connected.user data set when the signal handler was connected.
gstmultifdsink : the multifdsink element to emit this signal on
fd : the file descriptor to add to multifdsink
user_data : user data set when the signal handler was connected.

The "clear" signal

void        user_function                  (GstMultiFdSink *gstmultifdsink,
                                            gpointer        user_data)           : Run last

Remove all file descriptors from multifdsink. Since multifdsink did not open fd's itself, it does not explicitly close the fd. The application should do so by connecting to the client-fd-removed callback.

gstmultifdsink :gstmultifdsink the multifdsink element to emit this signal on the multifdsink element to emit this signal on user_data :user_datauser data set when the signal handler was connected.user data set when the signal handler was connected.
gstmultifdsink : the multifdsink element to emit this signal on
user_data : user data set when the signal handler was connected.

The "client-added" signal

void        user_function                  (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gpointer        user_data)           : Run last

The given file descriptor was added to multifdsink. This signal will be emitted from the streaming thread so application should be prepared for that.

gstmultifdsink :gstmultifdsink the multifdsink element that emitted this signal the multifdsink element that emitted this signal fd :fd the file descriptor that was added to multifdsink the file descriptor that was added to multifdsink user_data :user_datauser data set when the signal handler was connected.user data set when the signal handler was connected.
gstmultifdsink : the multifdsink element that emitted this signal
fd : the file descriptor that was added to multifdsink
user_data : user data set when the signal handler was connected.

The "client-removed" signal

void        user_function                  (GstMultiFdSink  *gstmultifdsink,
                                            gint             fd,
                                            GstClientStatus *status,
                                            gpointer         user_data)           : Run last

The given file descriptor is about to be removed from multifdsink. This signal will be emitted from the streaming thread so applications should be prepared for that.

gstmultifdsink still holds a handle to fd so it is possible to call the get-stats signal from this callback. For the same reason it is not safe to close() and reuse fd in this callback.

gstmultifdsink :gstmultifdsink the multifdsink element that emitted this signal the multifdsink element that emitted this signal fd :fd the file descriptor that is to be removed from multifdsink the file descriptor that is to be removed from multifdsink status :status the reason why the client was removed the reason why the client was removed user_data :user_datauser data set when the signal handler was connected.user data set when the signal handler was connected.
gstmultifdsink : the multifdsink element that emitted this signal
fd : the file descriptor that is to be removed from multifdsink
status : the reason why the client was removed
user_data : user data set when the signal handler was connected.

The "get-stats" signal

GValueArray*user_function                  (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gpointer        user_data)           : Run last

Get statistics about fd. This function returns a GValueArray to ease automatic wrapping for bindings.

gstmultifdsink :gstmultifdsink the multifdsink element to emit this signal on the multifdsink element to emit this signal on fd :fd the file descriptor to get stats of from multifdsink the file descriptor to get stats of from multifdsink user_data :user_datauser data set when the signal handler was connected.user data set when the signal handler was connected.Returns :Returns a GValueArray with the statistics. The array contains guint64 values that represent respectively: total number of bytes sent, time when the client was added, time when the client was disconnected/removed, time the client is/was active, last activity time, number of buffers dropped. All times are expressed in nanoseconds (GstClockTime). a GValueArray with the statistics. The array contains guint64 values that represent respectively: total number of bytes sent, time when the client was added, time when the client was disconnected/removed, time the client is/was active, last activity time, number of buffers dropped. All times are expressed in nanoseconds (GstClockTime).
gstmultifdsink : the multifdsink element to emit this signal on
fd : the file descriptor to get stats of from multifdsink
user_data : user data set when the signal handler was connected.
Returns : a GValueArray with the statistics. The array contains guint64 values that represent respectively: total number of bytes sent, time when the client was added, time when the client was disconnected/removed, time the client is/was active, last activity time, number of buffers dropped. All times are expressed in nanoseconds (GstClockTime).

The "remove" signal

void        user_function                  (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gpointer        user_data)           : Run last

Remove the given open file descriptor from multifdsink.

gstmultifdsink :gstmultifdsink the multifdsink element to emit this signal on the multifdsink element to emit this signal on fd :fd the file descriptor to remove from multifdsink the file descriptor to remove from multifdsink user_data :user_datauser data set when the signal handler was connected.user data set when the signal handler was connected.
gstmultifdsink : the multifdsink element to emit this signal on
fd : the file descriptor to remove from multifdsink
user_data : user data set when the signal handler was connected.

The "client-fd-removed" signal

void        user_function                  (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gpointer        user_data)           : Run last

The given file descriptor was removed from multifdsink. This signal will be emitted from the streaming thread so applications should be prepared for that.

In this callback, gstmultifdsink has removed all the information associated with fd and it is therefore not possible to call get-stats with fd. It is however safe to close() and reuse fd in the callback.

gstmultifdsink :gstmultifdsink the multifdsink element that emitted this signal the multifdsink element that emitted this signal fd :fd the file descriptor that was removed from multifdsink the file descriptor that was removed from multifdsink user_data :user_datauser data set when the signal handler was connected.user data set when the signal handler was connected.
gstmultifdsink : the multifdsink element that emitted this signal
fd : the file descriptor that was removed from multifdsink
user_data : user data set when the signal handler was connected.

Since 0.10.7


The "add-full" signal

void        user_function                  (GstMultiFdSink *gstmultifdsink,
                                            gint            fd,
                                            gboolean        keyframe,
                                            GstTCPUnitType *unit_type_min,
                                            guint64         value_min,
                                            GstTCPUnitType *unit_type_max,
                                            guint64         value_max,
                                            gpointer        user_data)           : Run last

Hand the given open file descriptor to multifdsink to write to and specify the burst parameters for the new connection.

gstmultifdsink :gstmultifdsink the multifdsink element to emit this signal on the multifdsink element to emit this signal on fd :fd the file descriptor to add to multifdsink the file descriptor to add to multifdsink keyframe :keyframe start bursting from a keyframe start bursting from a keyframe unit_type_min :unit_type_min the unit-type of value_min the unit-type of value_min value_minvalue_min :value_min the minimum amount of data to burst expressed in unit_type_min units. the minimum amount of data to burst expressed in unit_type_min units. unit_type_minunit_type_max :unit_type_max the unit-type of value_max the unit-type of value_max value_maxvalue_max :value_max the maximum amount of data to burst expressed in unit_type_max units. the maximum amount of data to burst expressed in unit_type_max units. unit_type_maxuser_data :user_datauser data set when the signal handler was connected.user data set when the signal handler was connected.
gstmultifdsink : the multifdsink element to emit this signal on
fd : the file descriptor to add to multifdsink
keyframe : start bursting from a keyframe
unit_type_min : the unit-type of value_min
value_min : the minimum amount of data to burst expressed in unit_type_min units.
unit_type_max : the unit-type of value_max
value_max : the maximum amount of data to burst expressed in unit_type_max units.
user_data : user data set when the signal handler was connected.

See Also

tcpserversink