GstAppSink

typedef struct {
  GstBaseSink basesink;
} GstAppSink;

gst_app_sink_set_caps ()

void                gst_app_sink_set_caps               (GstAppSink *appsink,
                                                         const GstCaps *caps);

Set the capabilities on the appsink element. This function takes a copy of the caps structure. After calling this method, the sink will only accept caps that match caps. If caps is non-fixed, you must check the caps on the buffers to get the actual used caps.

Since 0.10.22

gst_app_sink_get_caps ()

GstCaps*            gst_app_sink_get_caps               (GstAppSink *appsink);

Get the configured caps on appsink.

Since 0.10.22

gst_app_sink_is_eos ()

gboolean            gst_app_sink_is_eos                 (GstAppSink *appsink);

Check if appsink is EOS, which is when no more buffers can be pulled because an EOS event was received.

This function also returns TRUE when the appsink is not in the PAUSED or PLAYING state.

Since 0.10.22

gst_app_sink_set_emit_signals ()

void                gst_app_sink_set_emit_signals       (GstAppSink *appsink,
                                                         gboolean emit);

Make appsink emit the "new-preroll" and "new-buffer" signals. This option is by default disabled because signal emission is expensive and unneeded when the application prefers to operate in pull mode.

Since 0.10.22

gst_app_sink_get_emit_signals ()

gboolean            gst_app_sink_get_emit_signals       (GstAppSink *appsink);

Check if appsink will emit the "new-preroll" and "new-buffer" signals.

Since 0.10.22

gst_app_sink_set_max_buffers ()

void                gst_app_sink_set_max_buffers        (GstAppSink *appsink,
                                                         guint max);

Set the maximum amount of buffers that can be queued in appsink. After this amount of buffers are queued in appsink, any more buffers will block upstream elements until a buffer is pulled from appsink.

Since 0.10.22

gst_app_sink_get_max_buffers ()

guint               gst_app_sink_get_max_buffers        (GstAppSink *appsink);

Get the maximum amount of buffers that can be queued in appsink.

Since 0.10.22

gst_app_sink_set_drop ()

void                gst_app_sink_set_drop               (GstAppSink *appsink,
                                                         gboolean drop);

Instruct appsink to drop old buffers when the maximum amount of queued buffers is reached.

Since 0.10.22

gst_app_sink_get_drop ()

gboolean            gst_app_sink_get_drop               (GstAppSink *appsink);

Check if appsink will drop old buffers when the maximum amount of queued buffers is reached.

Since 0.10.22

gst_app_sink_pull_preroll ()

GstBuffer*          gst_app_sink_pull_preroll           (GstAppSink *appsink);

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().

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.

Since 0.10.22

gst_app_sink_pull_buffer ()

GstBuffer*          gst_app_sink_pull_buffer            (GstAppSink *appsink);

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.

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.

Since 0.10.22

GstAppSinkCallbacks

typedef struct {
  void          (*eos)              (GstAppSink *sink, gpointer user_data);
  GstFlowReturn (*new_preroll)      (GstAppSink *sink, gpointer user_data);
  GstFlowReturn (*new_buffer)       (GstAppSink *sink, gpointer user_data);
  GstFlowReturn (*new_buffer_list)  (GstAppSink *sink, gpointer user_data);
} GstAppSinkCallbacks;

A set of callbacks that can be installed on the appsink with gst_app_sink_set_callbacks().

Since 0.10.23

gst_app_sink_set_callbacks ()

void                gst_app_sink_set_callbacks          (GstAppSink *appsink,
                                                         GstAppSinkCallbacks *callbacks,
                                                         gpointer user_data,
                                                         GDestroyNotify notify);

Set callbacks which will be executed for each new preroll, new buffer and eos. This is an alternative to using the signals, it has lower overhead and is thus less expensive, but also less flexible.

If callbacks are installed, no signals will be emited for performance reasons.

Since 0.10.23