Drop buffers in gstreamer

Question

I am developing a gstreamer application (plugin) that sinks from a video stream, analyzes each buffer for a certain condition and then if that condition is present passes the buffer to the plugin source. If the condition is not present for a given buffer, the buffer should be dropped and the plugin source should not receive this buffer.

Upon looking through the gstreamer documentation and tutorials as a newcomer to gstreamer, I cannot find a way for my plugin to "drop" a buffer.

Answer 1

Try using GstProbe for data buffers and return GST_PAD_PROBE_DROP or GST_PAD_PROBE_HANDLED when yours conditions are met.

If your plugin is based on GstBaseTransform, you should implement your own transform_frame_ip or transform_frame. If so, you can return GST_BASE_TRANSFORM_FLOW_DROPPED:

/**
 * GST_BASE_TRANSFORM_FLOW_DROPPED:
 *
 * A #GstFlowReturn that can be returned from transform and transform_ip to
 * indicate that no output buffer was generated.
 */
#define GST_BASE_TRANSFORM_FLOW_DROPPED   GST_FLOW_CUSTOM_SUCCESS