From c6af0a39e780914a3155f7d8fb718614bc5d030f Mon Sep 17 00:00:00 2001 From: Vivia Nikolaidou Date: Mon, 24 Oct 2022 18:02:27 +0300 Subject: [PATCH] inputselector: Add drop-backwards property When sync-streams=true, drop backwards buffers on pad switch. Part-of: --- .../gstreamer/docs/plugins/gst_plugins_cache.json | 12 +++++ .../gstreamer/plugins/elements/gstinputselector.c | 54 +++++++++++++++++++++- .../gstreamer/plugins/elements/gstinputselector.h | 2 + 3 files changed, 67 insertions(+), 1 deletion(-) diff --git a/subprojects/gstreamer/docs/plugins/gst_plugins_cache.json b/subprojects/gstreamer/docs/plugins/gst_plugins_cache.json index 67927f5..cbe32ab 100644 --- a/subprojects/gstreamer/docs/plugins/gst_plugins_cache.json +++ b/subprojects/gstreamer/docs/plugins/gst_plugins_cache.json @@ -1332,6 +1332,18 @@ "type": "gboolean", "writable": true }, + "drop-backwards": { + "blurb": "Drop backwards buffers on pad switch", + "conditionally-available": false, + "construct": false, + "construct-only": false, + "controllable": false, + "default": "false", + "mutable": "ready", + "readable": true, + "type": "gboolean", + "writable": true + }, "n-pads": { "blurb": "The number of sink pads", "conditionally-available": false, diff --git a/subprojects/gstreamer/plugins/elements/gstinputselector.c b/subprojects/gstreamer/plugins/elements/gstinputselector.c index f673c46..e336519 100644 --- a/subprojects/gstreamer/plugins/elements/gstinputselector.c +++ b/subprojects/gstreamer/plugins/elements/gstinputselector.c @@ -101,13 +101,15 @@ enum PROP_ACTIVE_PAD, PROP_SYNC_STREAMS, PROP_SYNC_MODE, - PROP_CACHE_BUFFERS + PROP_CACHE_BUFFERS, + PROP_DROP_BACKWARDS }; #define DEFAULT_SYNC_STREAMS TRUE #define DEFAULT_SYNC_MODE GST_INPUT_SELECTOR_SYNC_MODE_ACTIVE_SEGMENT #define DEFAULT_CACHE_BUFFERS FALSE #define DEFAULT_PAD_ALWAYS_OK TRUE +#define DEFAULT_DROP_BACKWARDS FALSE enum { @@ -577,6 +579,7 @@ gst_selector_pad_event (GstPad * pad, GstObject * parent, GstEvent * event) break; case GST_EVENT_FLUSH_STOP: gst_selector_pad_reset (selpad); + sel->last_output_ts = GST_CLOCK_TIME_NONE; break; case GST_EVENT_SEGMENT: { @@ -1041,6 +1044,8 @@ gst_selector_pad_chain (GstPad * pad, GstObject * parent, GstBuffer * buf) GstPad *active_sinkpad; GstPad *prev_active_sinkpad = NULL; GstSelectorPad *selpad; + GstSegment seg; + GstClockTime running_time = GST_CLOCK_TIME_NONE; sel = GST_INPUT_SELECTOR (parent); selpad = GST_SELECTOR_PAD_CAST (pad); @@ -1165,7 +1170,25 @@ gst_selector_pad_chain (GstPad * pad, GstObject * parent, GstBuffer * buf) prev_active_sinkpad = NULL; } + seg = selpad->segment; + if (seg.format == GST_FORMAT_TIME) + running_time = + gst_segment_to_running_time (&seg, GST_FORMAT_TIME, + GST_BUFFER_DTS_OR_PTS (buf)); + if (selpad->discont) { + GST_INPUT_SELECTOR_LOCK (sel); + if (sel->sync_streams && sel->drop_backwards + && GST_CLOCK_TIME_IS_VALID (running_time)) { + /* Just switched. Make sure timestamps don't go backwards */ + if (running_time < sel->last_output_ts + && GST_CLOCK_TIME_IS_VALID (sel->last_output_ts)) { + GST_DEBUG_OBJECT (pad, "Discarding buffer %p with backwards timestamp", + buf); + goto ignore; + } + } + GST_INPUT_SELECTOR_UNLOCK (sel); buf = gst_buffer_make_writable (buf); GST_DEBUG_OBJECT (pad, "Marking discont buffer %p", buf); @@ -1176,6 +1199,7 @@ gst_selector_pad_chain (GstPad * pad, GstObject * parent, GstBuffer * buf) /* forward */ GST_LOG_OBJECT (pad, "Forwarding buffer %p with timestamp %" GST_TIME_FORMAT, buf, GST_TIME_ARGS (GST_BUFFER_PTS (buf))); + sel->last_output_ts = running_time; /* Only make the buffer read-only when necessary */ if (sel->sync_streams && sel->cache_buffers) @@ -1344,6 +1368,22 @@ gst_input_selector_class_init (GstInputSelectorClass * klass) G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | GST_PARAM_MUTABLE_READY)); + /** + * GstInputSelector:drop-backwards + * + * If set to %TRUE and GstInputSelector:sync-streams is also set to %TRUE, + * every time the input is switched, buffers that would go backwards related + * to the last output buffer pre-switch will be dropped. + * + * Since: 1.22 + */ + g_object_class_install_property (gobject_class, PROP_DROP_BACKWARDS, + g_param_spec_boolean ("drop-backwards", "Drop Backwards Buffers", + "Drop backwards buffers on pad switch", + DEFAULT_DROP_BACKWARDS, + G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | + GST_PARAM_MUTABLE_READY)); + gst_element_class_set_static_metadata (gstelement_class, "Input selector", "Generic", "N-to-1 input stream selector", "Julien Moutte , " @@ -1386,6 +1426,7 @@ gst_input_selector_init (GstInputSelector * sel) sel->eos = FALSE; sel->upstream_latency = 0; + sel->last_output_ts = GST_CLOCK_TIME_NONE; /* lets give a change for downstream to do something on * active-pad change before we start pushing new buffers */ @@ -1514,6 +1555,11 @@ gst_input_selector_set_property (GObject * object, guint prop_id, sel->cache_buffers = g_value_get_boolean (value); GST_INPUT_SELECTOR_UNLOCK (object); break; + case PROP_DROP_BACKWARDS: + GST_INPUT_SELECTOR_LOCK (object); + sel->drop_backwards = g_value_get_boolean (value); + GST_INPUT_SELECTOR_UNLOCK (object); + break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; @@ -1562,6 +1608,11 @@ gst_input_selector_get_property (GObject * object, guint prop_id, g_value_set_boolean (value, sel->cache_buffers); GST_INPUT_SELECTOR_UNLOCK (object); break; + case PROP_DROP_BACKWARDS: + GST_INPUT_SELECTOR_LOCK (object); + g_value_set_boolean (value, sel->drop_backwards); + GST_INPUT_SELECTOR_UNLOCK (object); + break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; @@ -1940,6 +1991,7 @@ gst_input_selector_reset (GstInputSelector * sel) } sel->have_group_id = TRUE; sel->upstream_latency = 0; + sel->last_output_ts = GST_CLOCK_TIME_NONE; GST_INPUT_SELECTOR_UNLOCK (sel); } diff --git a/subprojects/gstreamer/plugins/elements/gstinputselector.h b/subprojects/gstreamer/plugins/elements/gstinputselector.h index 79a5578..039f628 100644 --- a/subprojects/gstreamer/plugins/elements/gstinputselector.h +++ b/subprojects/gstreamer/plugins/elements/gstinputselector.h @@ -72,6 +72,7 @@ struct _GstInputSelector { gboolean sync_streams; GstInputSelectorSyncMode sync_mode; gboolean cache_buffers; + gboolean drop_backwards; gboolean have_group_id; @@ -82,6 +83,7 @@ struct _GstInputSelector { gboolean flushing; GstClockTime upstream_latency; + GstClockTime last_output_ts; }; struct _GstInputSelectorClass { -- 2.7.4