segmentclip: Add audio/video buffer segment clip elements

These elements clip the audio/video buffers to the configured segment
for the case when the upstream elements don't do this correctly.

configure.ac

@@ -296,6 +296,7 @@ AG_GST_CHECK_PLUGIN(real)
 AG_GST_CHECK_PLUGIN(rtpmux)
 AG_GST_CHECK_PLUGIN(scaletempo)
 AG_GST_CHECK_PLUGIN(sdp)
+AG_GST_CHECK_PLUGIN(segmentclip)
 AG_GST_CHECK_PLUGIN(selector)
 AG_GST_CHECK_PLUGIN(siren)
 AG_GST_CHECK_PLUGIN(speed)
@@ -1667,6 +1668,7 @@ gst/real/Makefile
 gst/rtpmux/Makefile
 gst/scaletempo/Makefile
 gst/sdp/Makefile
+gst/segmentclip/Makefile
 gst/selector/Makefile
 gst/siren/Makefile
 gst/speed/Makefile

gst/segmentclip/Makefile.am

@@ -0,0 +1,11 @@
+plugin_LTLIBRARIES = libgstsegmentclip.la
+
+libgstsegmentclip_la_SOURCES = gstsegmentclip.c gstaudiosegmentclip.c gstvideosegmentclip.c plugin.c
+
+libgstsegmentclip_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_CFLAGS)
+libgstsegmentclip_la_LIBADD = $(GST_PLUGINS_BASE_LIBS) $(GST_LIBS) -lgstaudio-@GST_MAJORMINOR@
+libgstsegmentclip_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
+libgstsegmentclip_la_LIBTOOLFLAGS = --tag=disable-static
+
+noinst_HEADERS = gstsegmentclip.h gstaudiosegmentclip.h gstvideosegmentclip.h
+

gst/segmentclip/gstaudiosegmentclip.c

@@ -0,0 +1,191 @@
+/* GStreamer
+ * Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include <gst/audio/audio.h>
+
+#include "gstaudiosegmentclip.h"
+
+static GstStaticPadTemplate sink_pad_template =
+    GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
+    GST_STATIC_CAPS
+    ("audio/x-raw-int, width=(int)[1,MAX], channels=(int)[1,MAX],rate=(int)[1,MAX]; audio/x-raw-float, width=(int)[1,MAX], channels=(int)[1,MAX],rate=(int)[1,MAX]"));
+
+static GstStaticPadTemplate src_pad_template =
+    GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
+    GST_STATIC_CAPS
+    ("audio/x-raw-int, width=(int)[1,MAX], channels=(int)[1,MAX],rate=(int)[1,MAX]; audio/x-raw-float, width=(int)[1,MAX], channels=(int)[1,MAX],rate=(int)[1,MAX]"));
+
+static void gst_audio_segment_clip_reset (GstSegmentClip * self);
+static GstFlowReturn gst_audio_segment_clip_clip_buffer (GstSegmentClip * self,
+    GstBuffer * buffer, GstBuffer ** outbuf);
+static gboolean gst_audio_segment_clip_set_caps (GstSegmentClip * self,
+    GstCaps * caps);
+
+GST_DEBUG_CATEGORY_STATIC (gst_audio_segment_clip_debug);
+#define GST_CAT_DEFAULT gst_audio_segment_clip_debug
+
+GST_BOILERPLATE (GstAudioSegmentClip, gst_audio_segment_clip, GstSegmentClip,
+    GST_TYPE_SEGMENT_CLIP);
+
+static void
+gst_audio_segment_clip_base_init (gpointer g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_set_details_simple (element_class,
+      "Audio buffer segment clipper",
+      "Filter/Audio",
+      "Clips audio buffers to the configured segment",
+      "Sebastian Dröge <sebastian.droege@collabora.co.uk>");
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&sink_pad_template));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&src_pad_template));
+}
+
+static void
+gst_audio_segment_clip_class_init (GstAudioSegmentClipClass * klass)
+{
+  GstSegmentClipClass *segment_clip_klass = GST_SEGMENT_CLIP_CLASS (klass);
+
+  GST_DEBUG_CATEGORY_INIT (gst_audio_segment_clip_debug, "audiosegmentclip", 0,
+      "audiosegmentclip element");
+
+  segment_clip_klass->reset = GST_DEBUG_FUNCPTR (gst_audio_segment_clip_reset);
+  segment_clip_klass->set_caps =
+      GST_DEBUG_FUNCPTR (gst_audio_segment_clip_set_caps);
+  segment_clip_klass->clip_buffer =
+      GST_DEBUG_FUNCPTR (gst_audio_segment_clip_clip_buffer);
+}
+
+static void
+gst_audio_segment_clip_init (GstAudioSegmentClip * self,
+    GstAudioSegmentClipClass * g_class)
+{
+}
+
+static void
+gst_audio_segment_clip_reset (GstSegmentClip * base)
+{
+  GstAudioSegmentClip *self = GST_AUDIO_SEGMENT_CLIP (base);
+
+  GST_DEBUG_OBJECT (self, "Resetting internal state");
+
+  self->rate = self->framesize = 0;
+}
+
+
+static GstFlowReturn
+gst_audio_segment_clip_clip_buffer (GstSegmentClip * base, GstBuffer * buffer,
+    GstBuffer ** outbuf)
+{
+  GstAudioSegmentClip *self = GST_AUDIO_SEGMENT_CLIP (base);
+  GstSegment *segment = &base->segment;
+  GstClockTime timestamp = GST_BUFFER_TIMESTAMP (buffer);
+  GstClockTime duration = GST_BUFFER_DURATION (buffer);
+  guint64 offset = GST_BUFFER_OFFSET (buffer);
+  guint64 offset_end = GST_BUFFER_OFFSET_END (buffer);
+  guint size = GST_BUFFER_SIZE (buffer);
+
+  if (!self->rate || !self->framesize) {
+    GST_ERROR_OBJECT (self, "Not negotiated yet");
+    gst_buffer_unref (buffer);
+    return GST_FLOW_NOT_NEGOTIATED;
+  }
+
+  if (segment->format != GST_FORMAT_DEFAULT &&
+      segment->format != GST_FORMAT_TIME) {
+    GST_DEBUG_OBJECT (self, "Unsupported segment format %s",
+        gst_format_get_name (segment->format));
+    *outbuf = buffer;
+    return GST_FLOW_OK;
+  }
+
+  if (!GST_BUFFER_TIMESTAMP_IS_VALID (buffer)) {
+    GST_WARNING_OBJECT (self, "Buffer without valid timestamp");
+    *outbuf = buffer;
+    return GST_FLOW_OK;
+  }
+
+  *outbuf =
+      gst_audio_buffer_clip (buffer, segment, self->rate, self->framesize);
+
+  if (!*outbuf) {
+    GST_DEBUG_OBJECT (self, "Buffer outside the configured segment");
+
+    /* Now return unexpected if we're before/after the end */
+    if (segment->format == GST_FORMAT_TIME) {
+      if (segment->rate >= 0) {
+        if (segment->stop != -1 && timestamp >= segment->stop)
+          return GST_FLOW_UNEXPECTED;
+      } else {
+        if (!GST_CLOCK_TIME_IS_VALID (duration))
+          duration =
+              gst_util_uint64_scale_int (size, GST_SECOND,
+              self->framesize * self->rate);
+
+        if (segment->start != -1 && timestamp + duration <= segment->start)
+          return GST_FLOW_UNEXPECTED;
+      }
+    } else {
+      if (segment->rate >= 0) {
+        if (segment->stop != -1 && offset != -1 && offset >= segment->stop)
+          return GST_FLOW_UNEXPECTED;
+      } else if (offset != -1 || offset_end != -1) {
+        if (offset_end == -1)
+          offset_end = offset + size / self->framesize;
+
+        if (segment->start != -1 && offset_end <= segment->start)
+          return GST_FLOW_UNEXPECTED;
+      }
+    }
+  }
+
+  return GST_FLOW_OK;
+}
+
+static gboolean
+gst_audio_segment_clip_set_caps (GstSegmentClip * base, GstCaps * caps)
+{
+  GstAudioSegmentClip *self = GST_AUDIO_SEGMENT_CLIP (base);
+  gboolean ret;
+  GstStructure *s;
+  gint rate, channels, width;
+
+  s = gst_caps_get_structure (caps, 0);
+
+  ret = gst_structure_get_int (s, "rate", &rate);
+  ret = ret && gst_structure_get_int (s, "channels", &channels);
+  ret = ret && gst_structure_get_int (s, "width", &width);
+
+  if (ret) {
+    GST_DEBUG_OBJECT (self, "Configured: rate %d channels %d width %d", rate,
+        channels, width);
+    self->rate = rate;
+    self->framesize = (width / 8) * channels;
+  }
+
+  return ret;
+}

gst/segmentclip/gstaudiosegmentclip.h

@@ -0,0 +1,61 @@
+/* GStreamer
+ * Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __GST_AUDIO_SEGMENT_CLIP_H__
+#define __GST_AUDIO_SEGMENT_CLIP_H__
+
+#include <gst/gst.h>
+#include "gstsegmentclip.h"
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_AUDIO_SEGMENT_CLIP \
+  (gst_audio_segment_clip_get_type())
+#define GST_AUDIO_SEGMENT_CLIP(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AUDIO_SEGMENT_CLIP,GstAudioSegmentClip))
+#define GST_AUDIO_SEGMENT_CLIP_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_AUDIO_SEGMENT_CLIP,GstAudioSegmentClipClass))
+#define GST_AUDIO_SEGMENT_CLIP_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj),GST_TYPE_AUDIO_SEGMENT_CLIP,GstAudioSegmentClipClass))
+#define GST_IS_AUDIO_SEGMENT_CLIP(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AUDIO_SEGMENT_CLIP))
+#define GST_IS_AUDIO_SEGMENT_CLIP_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AUDIO_SEGMENT_CLIP))
+
+typedef struct _GstAudioSegmentClip GstAudioSegmentClip;
+typedef struct _GstAudioSegmentClipClass GstAudioSegmentClipClass;
+
+struct _GstAudioSegmentClip
+{
+  GstSegmentClip parent;
+
+  /* < private > */
+  gint rate;
+  gint framesize;
+};
+
+struct _GstAudioSegmentClipClass
+{
+  GstSegmentClipClass parent_class;
+};
+
+GType gst_audio_segment_clip_get_type (void);
+
+G_END_DECLS
+
+#endif /* __GST_AUDIO_SEGMENT_CLIP_H__ */

gst/segmentclip/gstsegmentclip.c

@@ -0,0 +1,305 @@
+/* GStreamer
+ * Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+
+#include "gstsegmentclip.h"
+
+static void gst_segment_clip_reset (GstSegmentClip * self);
+
+static GstStateChangeReturn gst_segment_clip_change_state (GstElement * element,
+    GstStateChange transition);
+
+static GstFlowReturn gst_segment_clip_sink_chain (GstPad * pad,
+    GstBuffer * buffer);
+static gboolean gst_segment_clip_sink_setcaps (GstPad * pad, GstCaps * caps);
+static GstFlowReturn gst_segment_clip_sink_bufferalloc (GstPad * pad,
+    guint64 offset, guint size, GstCaps * caps, GstBuffer ** buf);
+
+static gboolean gst_segment_clip_event (GstPad * pad, GstEvent * event);
+static GstCaps *gst_segment_clip_getcaps (GstPad * pad);
+static gboolean gst_segment_clip_query (GstPad * pad, GstQuery * query);
+static const GstQueryType *gst_segment_clip_query_type (GstPad * pad);
+
+GST_DEBUG_CATEGORY_STATIC (gst_segment_clip_debug);
+#define GST_CAT_DEFAULT gst_segment_clip_debug
+
+GST_BOILERPLATE (GstSegmentClip, gst_segment_clip, GstElement,
+    GST_TYPE_ELEMENT);
+
+static void
+gst_segment_clip_base_init (gpointer g_class)
+{
+}
+
+static void
+gst_segment_clip_class_init (GstSegmentClipClass * klass)
+{
+  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
+
+  GST_DEBUG_CATEGORY_INIT (gst_segment_clip_debug, "segmentclip", 0,
+      "segmentclip base class");
+
+  gstelement_class->change_state =
+      GST_DEBUG_FUNCPTR (gst_segment_clip_change_state);
+}
+
+static void
+gst_segment_clip_init (GstSegmentClip * self, GstSegmentClipClass * g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+  GstPadTemplate *templ;
+
+  templ = gst_element_class_get_pad_template (element_class, "sink");
+  g_assert (templ);
+
+  self->sinkpad = gst_pad_new_from_template (templ, "sink");
+  gst_pad_set_chain_function (self->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_sink_chain));
+  gst_pad_set_event_function (self->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_event));
+  gst_pad_set_setcaps_function (self->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_sink_setcaps));
+  gst_pad_set_getcaps_function (self->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_getcaps));
+  gst_pad_set_bufferalloc_function (self->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_sink_bufferalloc));
+  gst_pad_set_query_function (self->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_query));
+  gst_pad_set_query_type_function (self->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_query_type));
+  gst_element_add_pad (GST_ELEMENT (self), self->sinkpad);
+
+  gst_object_unref (templ);
+
+  templ = gst_element_class_get_pad_template (element_class, "src");
+  g_assert (templ);
+
+  self->srcpad = gst_pad_new_from_template (templ, "src");
+  gst_pad_set_event_function (self->srcpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_event));
+  gst_pad_set_getcaps_function (self->srcpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_getcaps));
+  gst_pad_set_query_function (self->srcpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_query));
+  gst_pad_set_query_type_function (self->srcpad,
+      GST_DEBUG_FUNCPTR (gst_segment_clip_query_type));
+  gst_element_add_pad (GST_ELEMENT (self), self->srcpad);
+
+  gst_segment_clip_reset (self);
+}
+
+static void
+gst_segment_clip_reset (GstSegmentClip * self)
+{
+  GstSegmentClipClass *klass = GST_SEGMENT_CLIP_GET_CLASS (self);
+
+  GST_DEBUG_OBJECT (self, "Resetting internal state");
+
+  gst_segment_init (&self->segment, GST_FORMAT_UNDEFINED);
+  if (klass->reset)
+    klass->reset (self);
+}
+
+static GstFlowReturn
+gst_segment_clip_sink_bufferalloc (GstPad * pad, guint64 offset, guint size,
+    GstCaps * caps, GstBuffer ** buf)
+{
+  GstSegmentClip *self = GST_SEGMENT_CLIP (gst_pad_get_parent (pad));
+  GstFlowReturn ret = GST_FLOW_OK;
+
+  GST_LOG_OBJECT (pad, "Allocating buffer with offset 0x%" G_GINT64_MODIFIER
+      "x and size %u with caps: %" GST_PTR_FORMAT, offset, size, caps);
+
+  *buf = NULL;
+
+  ret = gst_pad_alloc_buffer (self->srcpad, offset, size, caps, buf);
+  if (G_UNLIKELY (ret != GST_FLOW_OK))
+    GST_ERROR_OBJECT (pad, "Allocating buffer failed: %s",
+        gst_flow_get_name (ret));
+
+  gst_object_unref (self);
+
+  return ret;
+}
+
+static gboolean
+gst_segment_clip_sink_setcaps (GstPad * pad, GstCaps * caps)
+{
+  GstSegmentClip *self = GST_SEGMENT_CLIP (gst_pad_get_parent (pad));
+  GstSegmentClipClass *klass = GST_SEGMENT_CLIP_GET_CLASS (self);
+  gboolean ret;
+
+  GST_DEBUG_OBJECT (pad, "Setting caps: %" GST_PTR_FORMAT, caps);
+  ret = klass->set_caps (self, caps);
+
+  gst_object_unref (self);
+
+  return ret;
+}
+
+static GstCaps *
+gst_segment_clip_getcaps (GstPad * pad)
+{
+  GstSegmentClip *self = GST_SEGMENT_CLIP (gst_pad_get_parent (pad));
+  GstPad *otherpad;
+  GstCaps *tmp, *ret;
+
+  otherpad = (pad == self->srcpad) ? self->sinkpad : self->srcpad;
+
+  tmp = gst_pad_peer_get_caps (otherpad);
+  if (tmp) {
+    ret = gst_caps_intersect (tmp, gst_pad_get_pad_template_caps (pad));
+    gst_caps_unref (tmp);
+  } else {
+    ret = gst_caps_copy (gst_pad_get_pad_template_caps (pad));
+  }
+
+  gst_object_unref (self);
+
+  GST_LOG_OBJECT (pad, "Returning caps: %" GST_PTR_FORMAT, ret);
+
+  return ret;
+}
+
+static gboolean
+gst_segment_clip_query (GstPad * pad, GstQuery * query)
+{
+  GstSegmentClip *self = GST_SEGMENT_CLIP (gst_pad_get_parent (pad));
+  gboolean ret;
+  GstPad *otherpad;
+
+  otherpad = (pad == self->srcpad) ? self->sinkpad : self->srcpad;
+
+  GST_LOG_OBJECT (pad, "Handling query of type '%s'",
+      gst_query_type_get_name (GST_QUERY_TYPE (query)));
+
+  ret = gst_pad_peer_query (otherpad, query);
+
+  gst_object_unref (self);
+  return ret;
+}
+
+static const GstQueryType *
+gst_segment_clip_query_type (GstPad * pad)
+{
+  GstSegmentClip *self = GST_SEGMENT_CLIP (gst_pad_get_parent (pad));
+  GstPad *otherpad, *peer;
+  const GstQueryType *types = NULL;
+
+  otherpad = (pad == self->srcpad) ? self->sinkpad : self->srcpad;
+  peer = gst_pad_get_peer (otherpad);
+  if (peer) {
+    types = gst_pad_get_query_types (peer);
+    gst_object_unref (peer);
+  }
+
+  gst_object_unref (self);
+
+  return types;
+}
+
+
+static GstFlowReturn
+gst_segment_clip_sink_chain (GstPad * pad, GstBuffer * buffer)
+{
+  GstSegmentClip *self = GST_SEGMENT_CLIP (GST_PAD_PARENT (pad));
+  GstFlowReturn ret;
+  GstSegmentClipClass *klass = GST_SEGMENT_CLIP_GET_CLASS (self);
+  GstBuffer *outbuf = NULL;
+
+  GST_LOG_OBJECT (pad,
+      "Handling buffer with timestamp %" GST_TIME_FORMAT " and duration %"
+      GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)),
+      GST_TIME_ARGS (GST_BUFFER_DURATION (buffer)));
+
+  ret = klass->clip_buffer (self, buffer, &outbuf);
+  if (ret == GST_FLOW_OK && outbuf)
+    ret = gst_pad_push (self->srcpad, outbuf);
+
+  return ret;
+}
+
+static GstStateChangeReturn
+gst_segment_clip_change_state (GstElement * element, GstStateChange transition)
+{
+  GstSegmentClip *self = GST_SEGMENT_CLIP (element);
+  GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
+
+  if (GST_ELEMENT_CLASS (parent_class)->change_state)
+    ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_READY_TO_PAUSED:
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+      gst_segment_clip_reset (self);
+      break;
+    default:
+      break;
+  }
+
+  return ret;
+}
+
+static gboolean
+gst_segment_clip_event (GstPad * pad, GstEvent * event)
+{
+  GstSegmentClip *self = GST_SEGMENT_CLIP (gst_pad_get_parent (pad));
+  GstPad *otherpad;
+  gboolean ret;
+
+  GST_LOG_OBJECT (pad, "Got %s event", GST_EVENT_TYPE_NAME (event));
+
+  otherpad = (pad == self->srcpad) ? self->sinkpad : self->srcpad;
+  ret = gst_pad_push_event (otherpad, event);
+
+  if (ret) {
+    switch (GST_EVENT_TYPE (event)) {
+      case GST_EVENT_NEWSEGMENT:{
+        GstFormat fmt;
+        gboolean is_update;
+        gint64 start, end, base;
+        gdouble rate;
+
+        gst_event_parse_new_segment (event, &is_update, &rate, &fmt, &start,
+            &end, &base);
+        GST_DEBUG_OBJECT (pad,
+            "Got NEWSEGMENT event in %s format, passing on (%"
+            GST_TIME_FORMAT " - %" GST_TIME_FORMAT ")",
+            gst_format_get_name (fmt), GST_TIME_ARGS (start),
+            GST_TIME_ARGS (end));
+        gst_segment_set_newsegment (&self->segment, is_update, rate, fmt, start,
+            end, base);
+        break;
+      }
+      case GST_EVENT_FLUSH_STOP:
+        gst_segment_clip_reset (self);
+        break;
+      default:
+        break;
+    }
+  }
+
+  gst_object_unref (self);
+  return ret;
+}

gst/segmentclip/gstsegmentclip.h

@@ -0,0 +1,66 @@
+/* GStreamer
+ * Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __GST_SEGMENT_CLIP_H__
+#define __GST_SEGMENT_CLIP_H__
+
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_SEGMENT_CLIP \
+  (gst_segment_clip_get_type())
+#define GST_SEGMENT_CLIP(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_SEGMENT_CLIP,GstSegmentClip))
+#define GST_SEGMENT_CLIP_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_SEGMENT_CLIP,GstSegmentClipClass))
+#define GST_SEGMENT_CLIP_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj),GST_TYPE_SEGMENT_CLIP,GstSegmentClipClass))
+#define GST_IS_SEGMENT_CLIP(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_SEGMENT_CLIP))
+#define GST_IS_SEGMENT_CLIP_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_SEGMENT_CLIP))
+
+typedef struct _GstSegmentClip GstSegmentClip;
+typedef struct _GstSegmentClipClass GstSegmentClipClass;
+
+struct _GstSegmentClip
+{
+  GstElement parent;
+
+  /* < private > */
+  GstPad *sinkpad;
+  GstPad *srcpad;
+
+  GstSegment segment;
+};
+
+struct _GstSegmentClipClass
+{
+  GstElementClass parent_class;
+
+  gboolean      (*set_caps)    (GstSegmentClip *self, GstCaps *caps);
+  GstFlowReturn (*clip_buffer) (GstSegmentClip *self, GstBuffer *buffer, GstBuffer **outbuf);
+  void          (*reset)       (GstSegmentClip *self);
+};
+
+GType gst_segment_clip_get_type (void);
+
+G_END_DECLS
+
+#endif /* __GST_SEGMENT_CLIP_H__ */

gst/segmentclip/gstvideosegmentclip.c

@@ -0,0 +1,193 @@
+/* GStreamer
+ * Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include <gst/video/video.h>
+
+#include "gstvideosegmentclip.h"
+
+static GstStaticPadTemplate sink_pad_template =
+    GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
+    GST_STATIC_CAPS
+    ("video/x-raw-yuv, framerate=" GST_VIDEO_FPS_RANGE "; "
+        "video/x-raw-rgb, framerate=" GST_VIDEO_FPS_RANGE "; "
+        "video/x-raw-grey, framerate=" GST_VIDEO_FPS_RANGE));
+
+
+static GstStaticPadTemplate src_pad_template =
+    GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
+    GST_STATIC_CAPS
+    ("video/x-raw-yuv, framerate=" GST_VIDEO_FPS_RANGE "; "
+        "video/x-raw-rgb, framerate=" GST_VIDEO_FPS_RANGE "; "
+        "video/x-raw-grey, framerate=" GST_VIDEO_FPS_RANGE));
+
+static void gst_video_segment_clip_reset (GstSegmentClip * self);
+static GstFlowReturn gst_video_segment_clip_clip_buffer (GstSegmentClip * self,
+    GstBuffer * buffer, GstBuffer ** outbuf);
+static gboolean gst_video_segment_clip_set_caps (GstSegmentClip * self,
+    GstCaps * caps);
+
+GST_DEBUG_CATEGORY_STATIC (gst_video_segment_clip_debug);
+#define GST_CAT_DEFAULT gst_video_segment_clip_debug
+
+GST_BOILERPLATE (GstVideoSegmentClip, gst_video_segment_clip, GstSegmentClip,
+    GST_TYPE_SEGMENT_CLIP);
+
+static void
+gst_video_segment_clip_base_init (gpointer g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_set_details_simple (element_class,
+      "Video buffer segment clipper",
+      "Filter/Video",
+      "Clips video buffers to the configured segment",
+      "Sebastian Dröge <sebastian.droege@collabora.co.uk>");
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&sink_pad_template));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&src_pad_template));
+}
+
+static void
+gst_video_segment_clip_class_init (GstVideoSegmentClipClass * klass)
+{
+  GstSegmentClipClass *segment_clip_klass = GST_SEGMENT_CLIP_CLASS (klass);
+
+  GST_DEBUG_CATEGORY_INIT (gst_video_segment_clip_debug, "videosegmentclip", 0,
+      "videosegmentclip element");
+
+  segment_clip_klass->reset = GST_DEBUG_FUNCPTR (gst_video_segment_clip_reset);
+  segment_clip_klass->set_caps =
+      GST_DEBUG_FUNCPTR (gst_video_segment_clip_set_caps);
+  segment_clip_klass->clip_buffer =
+      GST_DEBUG_FUNCPTR (gst_video_segment_clip_clip_buffer);
+}
+
+static void
+gst_video_segment_clip_init (GstVideoSegmentClip * self,
+    GstVideoSegmentClipClass * g_class)
+{
+}
+
+static void
+gst_video_segment_clip_reset (GstSegmentClip * base)
+{
+  GstVideoSegmentClip *self = GST_VIDEO_SEGMENT_CLIP (base);
+
+  GST_DEBUG_OBJECT (self, "Resetting internal state");
+
+  self->fps_n = self->fps_d = 0;
+}
+
+
+static GstFlowReturn
+gst_video_segment_clip_clip_buffer (GstSegmentClip * base, GstBuffer * buffer,
+    GstBuffer ** outbuf)
+{
+  GstVideoSegmentClip *self = GST_VIDEO_SEGMENT_CLIP (base);
+  GstSegment *segment = &base->segment;
+  GstClockTime timestamp, duration;
+  gint64 cstart, cstop;
+  gboolean in_seg;
+
+  if (!self->fps_d) {
+    GST_ERROR_OBJECT (self, "Not negotiated yet");
+    gst_buffer_unref (buffer);
+    return GST_FLOW_NOT_NEGOTIATED;
+  }
+
+  if (segment->format != GST_FORMAT_TIME) {
+    GST_DEBUG_OBJECT (self, "Unsupported segment format %s",
+        gst_format_get_name (segment->format));
+    *outbuf = buffer;
+    return GST_FLOW_OK;
+  }
+
+  if (!GST_BUFFER_TIMESTAMP_IS_VALID (buffer)) {
+    GST_WARNING_OBJECT (self, "Buffer without valid timestamp");
+    *outbuf = buffer;
+    return GST_FLOW_OK;
+  }
+
+  if (self->fps_n == 0) {
+    *outbuf = buffer;
+    return GST_FLOW_OK;
+  }
+
+  timestamp = GST_BUFFER_TIMESTAMP (buffer);
+  duration = GST_BUFFER_DURATION (buffer);
+  if (!GST_CLOCK_TIME_IS_VALID (duration))
+    duration = gst_util_uint64_scale (GST_SECOND, self->fps_d, self->fps_n);
+
+  in_seg =
+      gst_segment_clip (segment, GST_FORMAT_TIME, timestamp,
+      timestamp + duration, &cstart, &cstop);
+  if (in_seg) {
+    if (timestamp != cstart || timestamp + duration != cstop) {
+      *outbuf = gst_buffer_make_metadata_writable (buffer);
+
+      GST_BUFFER_TIMESTAMP (*outbuf) = cstart;
+      GST_BUFFER_DURATION (*outbuf) = cstop - cstart;
+    } else {
+      *outbuf = buffer;
+    }
+  } else {
+    GST_DEBUG_OBJECT (self, "Buffer outside the configured segment");
+
+    if (segment->rate >= 0) {
+      if (segment->stop != -1 && timestamp >= segment->stop)
+        return GST_FLOW_UNEXPECTED;
+    } else {
+      if (segment->start != -1 && timestamp + duration <= segment->start)
+        return GST_FLOW_UNEXPECTED;
+    }
+    gst_buffer_unref (buffer);
+  }
+
+
+  return GST_FLOW_OK;
+}
+
+static gboolean
+gst_video_segment_clip_set_caps (GstSegmentClip * base, GstCaps * caps)
+{
+  GstVideoSegmentClip *self = GST_VIDEO_SEGMENT_CLIP (base);
+  gboolean ret;
+  GstStructure *s;
+  gint fps_n, fps_d;
+
+  s = gst_caps_get_structure (caps, 0);
+
+  ret = gst_structure_get_fraction (s, "framerate", &fps_n, &fps_d);
+  ret = (fps_d != 0);
+
+  if (ret) {
+    GST_DEBUG_OBJECT (self, "Configured framerate %d/%d", fps_n, fps_d);
+    self->fps_n = fps_n;
+    self->fps_d = fps_d;
+  }
+
+  return ret;
+}

gst/segmentclip/gstvideosegmentclip.h

@@ -0,0 +1,60 @@
+/* GStreamer
+ * Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __GST_VIDEO_SEGMENT_CLIP_H__
+#define __GST_VIDEO_SEGMENT_CLIP_H__
+
+#include <gst/gst.h>
+#include "gstsegmentclip.h"
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_VIDEO_SEGMENT_CLIP \
+  (gst_video_segment_clip_get_type())
+#define GST_VIDEO_SEGMENT_CLIP(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_VIDEO_SEGMENT_CLIP,GstVideoSegmentClip))
+#define GST_VIDEO_SEGMENT_CLIP_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_VIDEO_SEGMENT_CLIP,GstVideoSegmentClipClass))
+#define GST_VIDEO_SEGMENT_CLIP_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj),GST_TYPE_VIDEO_SEGMENT_CLIP,GstVideoSegmentClipClass))
+#define GST_IS_VIDEO_SEGMENT_CLIP(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_VIDEO_SEGMENT_CLIP))
+#define GST_IS_VIDEO_SEGMENT_CLIP_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_VIDEO_SEGMENT_CLIP))
+
+typedef struct _GstVideoSegmentClip GstVideoSegmentClip;
+typedef struct _GstVideoSegmentClipClass GstVideoSegmentClipClass;
+
+struct _GstVideoSegmentClip
+{
+  GstSegmentClip parent;
+
+  /* < private > */
+  gint fps_n, fps_d;
+};
+
+struct _GstVideoSegmentClipClass
+{
+  GstSegmentClipClass parent_class;
+};
+
+GType gst_video_segment_clip_get_type (void);
+
+G_END_DECLS
+
+#endif /* __GST_VIDEO_SEGMENT_CLIP_H__ */

gst/segmentclip/plugin.c

@@ -0,0 +1,43 @@
+/* GStreamer
+ * Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstaudiosegmentclip.h"
+#include "gstvideosegmentclip.h"
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+  if (!gst_element_register (plugin, "audiosegmentclip", GST_RANK_NONE,
+          GST_TYPE_AUDIO_SEGMENT_CLIP) ||
+      !gst_element_register (plugin, "videosegmentclip", GST_RANK_NONE,
+          GST_TYPE_VIDEO_SEGMENT_CLIP))
+    return FALSE;
+
+  return TRUE;
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+    GST_VERSION_MINOR,
+    "segmentclip",
+    "Segment clip elements",
+    plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)