GstAppSink

typedef struct _GstAppSink GstAppSink;

The "caps" property

  "caps"                     GstCaps*              : Read / Write

The allowed caps for the sink pad.

The "drop" property

  "drop"                     gboolean              : Read / Write

Drop old buffers when the buffer queue is filled.

Default value: FALSE

The "emit-signals" property

  "emit-signals"             gboolean              : Read / Write

Emit new-preroll and new-buffer signals.

Default value: FALSE

The "eos" property

  "eos"                      gboolean              : Read

Check if the sink is EOS or not started.

Default value: TRUE

The "max-buffers" property

  "max-buffers"              guint                 : Read / Write

The maximum number of buffers to queue internally (0 = unlimited).

Default value: 0

The "eos" signal

void                user_function                      (GstAppSink *appsink,
                                                        gpointer    user_data)      : Run Last

Signal that the end-of-stream has been reached. This signal is emited from the steaming thread.

The "new-buffer" signal

void                user_function                      (GstAppSink *appsink,
                                                        gpointer    user_data)      : Run Last

Signal that a new buffer is available.

This signal is emited from the steaming thread and only when the "emit-signals" property is TRUE.

The new buffer can be retrieved with the "pull-buffer" action signal or gst_app_sink_pull_buffer() either from this signal callback or from any other thread.

Note that this signal is only emited when the "emit-signals" property is set to TRUE, which it is not by default for performance reasons.

The "new-preroll" signal

void                user_function                      (GstAppSink *appsink,
                                                        gpointer    user_data)      : Run Last

Signal that a new preroll buffer is available.

This signal is emited from the steaming thread and only when the "emit-signals" property is TRUE.

The new preroll buffer can be retrieved with the "pull-preroll" action signal or gst_app_sink_pull_preroll() either from this signal callback or from any other thread.

Note that this signal is only emited when the "emit-signals" property is set to TRUE, which it is not by default for performance reasons.

The "pull-buffer" signal

GstBuffer*          user_function                      (GstAppSink *appsink,
                                                        gpointer    user_data)      : Run Last / Action

This function blocks until a buffer or EOS becomes available or the appsink element is set to the READY/NULL state.

This function will only return buffers when the appsink is in the PLAYING state. All rendered buffers will be put in a queue so that the application can pull buffers at its own rate.

Note that when the application does not pull buffers fast enough, the queued buffers could consume a lot of memory, especially when dealing with raw video frames. It's possible to control the behaviour of the queue with the "drop" and "max-buffers" properties.

If an EOS event was received before any buffers, this function returns NULL. Use gst_app_sink_is_eos() to check for the EOS condition.

The "pull-preroll" signal

GstBuffer*          user_function                      (GstAppSink *appsink,
                                                        gpointer    user_data)      : Run Last / Action

Get the last preroll buffer in appsink. This was the buffer that caused the appsink to preroll in the PAUSED state. This buffer can be pulled many times and remains available to the application even after EOS.

This function is typically used when dealing with a pipeline in the PAUSED state. Calling this function after doing a seek will give the buffer right after the seek position.

Note that the preroll buffer will also be returned as the first buffer when calling gst_app_sink_pull_buffer() or the "pull-buffer" action signal.

If an EOS event was received before any buffers, this function returns NULL. Use gst_app_sink_is_eos() to check for the EOS condition.

This function blocks until a preroll buffer or EOS is received or the appsink element is set to the READY/NULL state.

The "new-buffer-list" signal

void                user_function                      (GstAppSink *appsink,
                                                        gpointer    user_data)      : Run Last

Signal that a new bufferlist is available.

This signal is emited from the steaming thread and only when the "emit-signals" property is TRUE.

The new buffer can be retrieved with the "pull-buffer-list" action signal or gst_app_sink_pull_buffe_listr() either from this signal callback or from any other thread.

Note that this signal is only emited when the "emit-signals" property is set to TRUE, which it is not by default for performance reasons.

The "pull-buffer-list" signal

GstBufferList*      user_function                      (GstAppSink *appsink,
                                                        gpointer    user_data)      : Run Last / Action

This function blocks until a buffer list or EOS becomes available or the appsink element is set to the READY/NULL state.

This function will only return bufferlists when the appsink is in the PLAYING state. All rendered bufferlists will be put in a queue so that the application can pull bufferlists at its own rate.

Note that when the application does not pull bufferlists fast enough, the queued bufferlists could consume a lot of memory, especially when dealing with raw video frames. It's possible to control the behaviour of the queue with the "drop" and "max-buffers" properties.

If an EOS event was received before any buffers, this function returns NULL. Use gst_app_sink_is_eos() to check for the EOS condition.