applemedia: new AVSampleBufferLayerSink

Renders buffers using the CALayer subclass AVSampleBufferDisplayLayer
which can be placed inside a Core Animation render tree.

4 files changed, 845 insertions, 1 deletions

diff --git a/sys/applemedia/Makefile.am b/sys/applemedia/Makefile.am
index 9fd1fb2c7..795832c3e 100644
--- a/sys/applemedia/Makefile.am
+++ b/sys/applemedia/Makefile.am
@@ -89,7 +89,8 @@ if HAVE_AVFOUNDATION
 
 libgstapplemedia_la_SOURCES +=			\
 	avfvideosrc.m				\
-	avfassetsrc.m
+	avfassetsrc.m				\
+	avsamplevideosink.m
 
 libgstapplemedia_la_LDFLAGS +=			\
 	-Wl,-framework -Wl,AVFoundation
diff --git a/sys/applemedia/avsamplevideosink.h b/sys/applemedia/avsamplevideosink.h
new file mode 100644
index 000000000..6df11da7a
--- /dev/null
+++ b/sys/applemedia/avsamplevideosink.h
@@ -0,0 +1,71 @@
+/*
+ * GStreamer
+ * Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
+ *
+ * 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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef _AV_SINK_H_
+#define _AV_SINK_H_
+
+#include <gst/gst.h>
+#include <gst/video/gstvideosink.h>
+#include <gst/video/video.h>
+
+#include <QuartzCore/QuartzCore.h>
+#include <CoreFoundation/CoreFoundation.h>
+#include <CoreMedia/CoreMedia.h>
+#include <AVFoundation/AVFoundation.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_AV_SAMPLE_VIDEO_SINK \
+    (gst_av_sample_video_sink_get_type())
+#define GST_AV_SAMPLE_VIDEO_SINK(obj) \
+    (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AV_SAMPLE_VIDEO_SINK,GstAVSampleVideoSink))
+#define GST_AV_SAMPLE_VIDEO_SINK_CLASS(klass) \
+    (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_AV_SAMPLE_VIDEO_SINK,GstAVSampleVideoSinkClass))
+#define GST_IS_AV_SAMPLE_VIDEO_SINK(obj) \
+    (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AV_SAMPLE_VIDEO_SINK))
+#define GST_IS_AV_SAMPLE_VIDEO_SINK_CLASS(klass) \
+    (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AV_SAMPLE_VIDEO_SINK))
+
+typedef struct _GstAVSampleVideoSink GstAVSampleVideoSink;
+typedef struct _GstAVSampleVideoSinkClass GstAVSampleVideoSinkClass;
+
+struct _GstAVSampleVideoSink
+{
+    GstVideoSink video_sink;
+
+    AVSampleBufferDisplayLayer *layer;
+
+    GstVideoInfo info;
+
+    gboolean keep_aspect_ratio;
+
+    GstBufferPool *pool;
+};
+
+struct _GstAVSampleVideoSinkClass
+{
+    GstVideoSinkClass video_sink_class;
+};
+
+GType gst_av_sample_video_sink_get_type(void);
+
+G_END_DECLS
+
+#endif
diff --git a/sys/applemedia/avsamplevideosink.m b/sys/applemedia/avsamplevideosink.m
new file mode 100644
index 000000000..a4c2847ca
--- /dev/null
+++ b/sys/applemedia/avsamplevideosink.m
@@ -0,0 +1,768 @@
+/*
+ * GStreamer
+ * Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
+ *
+ * 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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+/**
+ * SECTION:element-avsamplebufferlayersink
+ *
+ * avsamplebufferlayersink renders video frames to a CALayer that can placed
+ * inside a Core Animation render tree.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "avsamplevideosink.h"
+
+GST_DEBUG_CATEGORY (gst_debug_av_sink);
+#define GST_CAT_DEFAULT gst_debug_av_sink
+
+static void gst_av_sample_video_sink_finalize (GObject * object);
+static void gst_av_sample_video_sink_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * param_spec);
+static void gst_av_sample_video_sink_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * param_spec);
+
+static gboolean gst_av_sample_video_sink_start (GstBaseSink * bsink);
+static gboolean gst_av_sample_video_sink_stop (GstBaseSink * bsink);
+
+static void gst_av_sample_video_sink_get_times (GstBaseSink * bsink, GstBuffer * buf,
+    GstClockTime * start, GstClockTime * end);
+static gboolean gst_av_sample_video_sink_set_caps (GstBaseSink * bsink, GstCaps * caps);
+static GstCaps * gst_av_sample_video_sink_get_caps (GstBaseSink * bsink, GstCaps * filter);
+static GstFlowReturn gst_av_sample_video_sink_prepare (GstBaseSink * bsink,
+    GstBuffer * buf);
+static GstFlowReturn gst_av_sample_video_sink_show_frame (GstVideoSink * bsink,
+    GstBuffer * buf);
+static gboolean gst_av_sample_video_sink_propose_allocation (GstBaseSink * bsink,
+    GstQuery * query);
+
+static GstStaticPadTemplate gst_av_sample_video_sink_template =
+    GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("{ RGB, BGR, ARGB, BGRA, ABGR, RGBA, YUY2, UYVY, NV12, I420 }"))
+    );
+
+enum
+{
+  PROR_0,
+  PROP_FORCE_ASPECT_RATIO,
+  PROP_LAYER,
+};
+
+#define gst_av_sample_video_sink_parent_class parent_class
+G_DEFINE_TYPE_WITH_CODE (GstAVSampleVideoSink, gst_av_sample_video_sink,
+    GST_TYPE_VIDEO_SINK, GST_DEBUG_CATEGORY_INIT (gst_debug_av_sink, "avsamplevideosink", 0,
+        "AV Sample Video Sink"));
+
+static void
+gst_av_sample_video_sink_class_init (GstAVSampleVideoSinkClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+  GstBaseSinkClass *gstbasesink_class;
+  GstVideoSinkClass *gstvideosink_class;
+  GstElementClass *element_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstelement_class = (GstElementClass *) klass;
+  gstbasesink_class = (GstBaseSinkClass *) klass;
+  gstvideosink_class = (GstVideoSinkClass *) klass;
+  element_class = GST_ELEMENT_CLASS (klass);
+
+  gobject_class->set_property = gst_av_sample_video_sink_set_property;
+  gobject_class->get_property = gst_av_sample_video_sink_get_property;
+
+  g_object_class_install_property (gobject_class, PROP_FORCE_ASPECT_RATIO,
+      g_param_spec_boolean ("force-aspect-ratio",
+          "Force aspect ratio",
+          "When enabled, scaling will respect original aspect ratio", TRUE,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_class, PROP_LAYER,
+      g_param_spec_pointer ("layer", "CALayer",
+          "The CoreAnimation layer that can be placed in the render tree",
+          G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
+
+  gst_element_class_set_metadata (element_class, "AV Sample video sink",
+      "Sink/Video", "A videosink based on AVSampleBuffer's",
+      "Matthew Waters <matthew@centricular.com>");
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_av_sample_video_sink_template));
+
+  gobject_class->finalize = gst_av_sample_video_sink_finalize;
+
+  gstbasesink_class->get_caps = gst_av_sample_video_sink_get_caps;
+  gstbasesink_class->set_caps = gst_av_sample_video_sink_set_caps;
+  gstbasesink_class->get_times = gst_av_sample_video_sink_get_times;
+  gstbasesink_class->prepare = gst_av_sample_video_sink_prepare;
+  gstbasesink_class->propose_allocation = gst_av_sample_video_sink_propose_allocation;
+  gstbasesink_class->stop = gst_av_sample_video_sink_stop;
+  gstbasesink_class->start = gst_av_sample_video_sink_start;
+
+  gstvideosink_class->show_frame =
+      GST_DEBUG_FUNCPTR (gst_av_sample_video_sink_show_frame);
+}
+
+static void
+gst_av_sample_video_sink_init (GstAVSampleVideoSink * av_sink)
+{
+  av_sink->keep_aspect_ratio = TRUE;
+}
+
+static void
+gst_av_sample_video_sink_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstAVSampleVideoSink *av_sink;
+
+  g_return_if_fail (GST_IS_AV_SAMPLE_VIDEO_SINK (object));
+
+  av_sink = GST_AV_SAMPLE_VIDEO_SINK (object);
+
+  switch (prop_id) {
+    case PROP_FORCE_ASPECT_RATIO:
+    {
+      av_sink->keep_aspect_ratio = g_value_get_boolean (value);
+      break;
+    }
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_av_sample_video_sink_finalize (GObject * object)
+{
+  GstAVSampleVideoSink *av_sink = GST_AV_SAMPLE_VIDEO_SINK (object);
+
+  if (av_sink->layer) {
+    dispatch_async (dispatch_get_main_queue (), ^{
+      [av_sink->layer release];
+    });
+  }
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gst_av_sample_video_sink_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstAVSampleVideoSink *av_sink;
+
+  g_return_if_fail (GST_IS_AV_SAMPLE_VIDEO_SINK (object));
+
+  av_sink = GST_AV_SAMPLE_VIDEO_SINK (object);
+
+  switch (prop_id) {
+    case PROP_FORCE_ASPECT_RATIO:
+      g_value_set_boolean (value, av_sink->keep_aspect_ratio);
+      break;
+    case PROP_LAYER:
+      g_value_set_pointer (value, av_sink->layer);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static gboolean
+gst_av_sample_video_sink_start (GstBaseSink * bsink)
+{
+  GstAVSampleVideoSink *av_sink = GST_AV_SAMPLE_VIDEO_SINK (bsink);
+
+  if ([NSThread isMainThread]) {
+    av_sink->layer = [[AVSampleBufferDisplayLayer alloc] init];
+    if (av_sink->keep_aspect_ratio)
+      av_sink->layer.videoGravity = AVLayerVideoGravityResizeAspect;
+    else
+      av_sink->layer.videoGravity = AVLayerVideoGravityResize;
+    g_object_notify (G_OBJECT (av_sink), "layer");
+  } else {
+    dispatch_sync (dispatch_get_main_queue (), ^{
+      av_sink->layer = [[AVSampleBufferDisplayLayer alloc] init];
+      if (av_sink->keep_aspect_ratio)
+        av_sink->layer.videoGravity = AVLayerVideoGravityResizeAspect;
+      else
+        av_sink->layer.videoGravity = AVLayerVideoGravityResize;
+      g_object_notify (G_OBJECT (av_sink), "layer");
+    });
+  }
+
+  return TRUE;
+}
+
+static gboolean
+gst_av_sample_video_sink_stop (GstBaseSink * bsink)
+{
+  GstAVSampleVideoSink *av_sink = GST_AV_SAMPLE_VIDEO_SINK (bsink);
+
+  if (av_sink->pool) {
+    gst_object_unref (av_sink->pool);
+    av_sink->pool = NULL;
+  }
+
+  if (av_sink->layer) {
+    dispatch_async (dispatch_get_main_queue (), ^{
+      [av_sink->layer flushAndRemoveImage];
+    });
+  }
+
+  return TRUE;
+}
+
+static void
+gst_av_sample_video_sink_get_times (GstBaseSink * bsink, GstBuffer * buf,
+    GstClockTime * start, GstClockTime * end)
+{
+  GstAVSampleVideoSink *av_sink;
+
+  av_sink = GST_AV_SAMPLE_VIDEO_SINK (bsink);
+
+  if (GST_BUFFER_TIMESTAMP_IS_VALID (buf)) {
+    *start = GST_BUFFER_TIMESTAMP (buf);
+    if (GST_BUFFER_DURATION_IS_VALID (buf))
+      *end = *start + GST_BUFFER_DURATION (buf);
+    else {
+      if (GST_VIDEO_INFO_FPS_N (&av_sink->info) > 0) {
+        *end = *start +
+            gst_util_uint64_scale_int (GST_SECOND,
+            GST_VIDEO_INFO_FPS_D (&av_sink->info),
+            GST_VIDEO_INFO_FPS_N (&av_sink->info));
+      }
+    }
+  }
+}
+
+static unsigned int
+_cv_pixel_format_type_from_video_format (GstVideoFormat format)
+{
+  switch (format) {
+    case GST_VIDEO_FORMAT_BGRA:
+      return kCVPixelFormatType_32BGRA;
+    case GST_VIDEO_FORMAT_ARGB:
+      return kCVPixelFormatType_32ARGB;
+    case GST_VIDEO_FORMAT_ABGR:
+      return kCVPixelFormatType_32ABGR;
+    case GST_VIDEO_FORMAT_RGBA:
+      return kCVPixelFormatType_32RGBA;
+    case GST_VIDEO_FORMAT_RGB:
+      return kCVPixelFormatType_24RGB;
+    case GST_VIDEO_FORMAT_BGR:
+      return kCVPixelFormatType_24BGR;
+#if 0
+    /* FIXME doesn't seem to work */
+    case GST_VIDEO_FORMAT_NV12:
+      return kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange;
+#endif
+    case GST_VIDEO_FORMAT_I420:
+      return kCVPixelFormatType_420YpCbCr8Planar;
+    case GST_VIDEO_FORMAT_YUY2:
+      return kCVPixelFormatType_422YpCbCr8_yuvs;
+    case GST_VIDEO_FORMAT_UYVY:
+      return kCVPixelFormatType_422YpCbCr8;
+    default:
+      return 0;
+  }
+}
+
+static GstVideoFormat
+_pixel_format_description_to_video_format (CFDictionaryRef attrs)
+{
+  CFNumberRef id_ref;
+  unsigned int id;
+
+  id_ref = (CFNumberRef) CFDictionaryGetValue (attrs, kCVPixelFormatConstant);
+  CFNumberGetValue (id_ref, kCFNumberIntType, &id);
+
+  GST_TRACE ("pixel format description id %u", id);
+
+  CFRelease (id_ref);
+
+  switch (id) {
+    case kCVPixelFormatType_32BGRA:
+      return GST_VIDEO_FORMAT_BGRA;
+    case kCVPixelFormatType_32ARGB:
+      return GST_VIDEO_FORMAT_ARGB;
+    case kCVPixelFormatType_32ABGR:
+      return GST_VIDEO_FORMAT_ABGR;
+    case kCVPixelFormatType_32RGBA:
+      return GST_VIDEO_FORMAT_RGBA;
+    case kCVPixelFormatType_24RGB:
+      return GST_VIDEO_FORMAT_RGB;
+    case kCVPixelFormatType_24BGR:
+      return GST_VIDEO_FORMAT_BGR;
+#if 0
+    case kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange:
+      return GST_VIDEO_FORMAT_NV12;
+#endif
+    case kCVPixelFormatType_420YpCbCr8Planar:
+      return GST_VIDEO_FORMAT_I420;
+    case kCVPixelFormatType_422YpCbCr8_yuvs:
+      return GST_VIDEO_FORMAT_YUY2;
+    case kCVPixelFormatType_422YpCbCr8:
+      return GST_VIDEO_FORMAT_UYVY;
+    default:
+      return GST_VIDEO_FORMAT_UNKNOWN;
+  }
+}
+
+static GstCaps *
+gst_av_sample_video_sink_get_caps (GstBaseSink * bsink, GstCaps * filter)
+{
+  GstAVSampleVideoSink *av_sink = GST_AV_SAMPLE_VIDEO_SINK (bsink);
+  CFArrayRef formats;
+  GstCaps *ret, *tmp;
+  int i, n;
+
+  formats =
+      CVPixelFormatDescriptionArrayCreateWithAllPixelFormatTypes
+      (kCFAllocatorDefault);
+
+  ret = gst_caps_new_empty ();
+
+  n = CFArrayGetCount (formats);
+  for (i = 0; i < n; i++) {
+    CFDictionaryRef attrs;
+    CFNumberRef fourcc;
+    unsigned int pixel_format;
+    GstVideoFormat v_format;
+    const char *format_str;
+    char *caps_str;
+
+    fourcc = (CFNumberRef)CFArrayGetValueAtIndex(formats, i);
+    CFNumberGetValue (fourcc, kCFNumberIntType, &pixel_format);
+    attrs = CVPixelFormatDescriptionCreateWithPixelFormatType (kCFAllocatorDefault,
+        pixel_format);
+
+    CFRelease (fourcc);
+
+    v_format = _pixel_format_description_to_video_format (attrs);
+    if (v_format != GST_VIDEO_FORMAT_UNKNOWN) {
+      format_str = gst_video_format_to_string (v_format);
+
+      caps_str = g_strdup_printf ("video/x-raw, format=%s", format_str);
+
+      ret = gst_caps_merge (ret, gst_caps_from_string (caps_str));
+
+      g_free (caps_str);
+    }
+
+    CFRelease (attrs);
+  }
+
+  ret = gst_caps_simplify (ret);
+
+  gst_caps_set_simple (ret, "width", GST_TYPE_INT_RANGE, 0, G_MAXINT, "height",
+      GST_TYPE_INT_RANGE, 0, G_MAXINT, "framerate", GST_TYPE_FRACTION_RANGE, 0,
+      1, G_MAXINT, 1, NULL);
+  GST_DEBUG_OBJECT (av_sink, "returning caps %" GST_PTR_FORMAT, ret);
+
+  if (filter) {
+    tmp = gst_caps_intersect_full (ret, filter, GST_CAPS_INTERSECT_FIRST);
+    gst_caps_unref (ret);
+    ret = tmp;
+  }
+
+  CFRelease (formats);
+
+  return ret;
+}
+
+static gboolean
+gst_av_sample_video_sink_set_caps (GstBaseSink * bsink, GstCaps * caps)
+{
+  GstAVSampleVideoSink *av_sink;
+  gint width;
+  gint height;
+  gboolean ok;
+  gint par_n, par_d;
+  gint display_par_n, display_par_d;
+  guint display_ratio_num, display_ratio_den;
+  GstVideoInfo vinfo;
+  GstStructure *structure;
+  GstBufferPool *newpool, *oldpool;
+
+  GST_DEBUG_OBJECT (bsink, "set caps with %" GST_PTR_FORMAT, caps);
+
+  av_sink = GST_AV_SAMPLE_VIDEO_SINK (bsink);
+
+  ok = gst_video_info_from_caps (&vinfo, caps);
+  if (!ok)
+    return FALSE;
+
+  width = GST_VIDEO_INFO_WIDTH (&vinfo);
+  height = GST_VIDEO_INFO_HEIGHT (&vinfo);
+
+  par_n = GST_VIDEO_INFO_PAR_N (&vinfo);
+  par_d = GST_VIDEO_INFO_PAR_D (&vinfo);
+
+  if (!par_n)
+    par_n = 1;
+
+  display_par_n = 1;
+  display_par_d = 1;
+
+  ok = gst_video_calculate_display_ratio (&display_ratio_num,
+      &display_ratio_den, width, height, par_n, par_d, display_par_n,
+      display_par_d);
+
+  if (!ok)
+    return FALSE;
+
+  GST_TRACE_OBJECT (bsink, "PAR: %u/%u DAR:%u/%u", par_n, par_d, display_par_n,
+      display_par_d);
+
+  if (height % display_ratio_den == 0) {
+    GST_DEBUG_OBJECT (bsink, "keeping video height");
+    GST_VIDEO_SINK_WIDTH (av_sink) = (guint)
+        gst_util_uint64_scale_int (height, display_ratio_num,
+        display_ratio_den);
+    GST_VIDEO_SINK_HEIGHT (av_sink) = height;
+  } else if (width % display_ratio_num == 0) {
+    GST_DEBUG_OBJECT (bsink, "keeping video width");
+    GST_VIDEO_SINK_WIDTH (av_sink) = width;
+    GST_VIDEO_SINK_HEIGHT (av_sink) = (guint)
+        gst_util_uint64_scale_int (width, display_ratio_den, display_ratio_num);
+  } else {
+    GST_DEBUG_OBJECT (bsink, "approximating while keeping video height");
+    GST_VIDEO_SINK_WIDTH (av_sink) = (guint)
+        gst_util_uint64_scale_int (height, display_ratio_num,
+        display_ratio_den);
+    GST_VIDEO_SINK_HEIGHT (av_sink) = height;
+  }
+  GST_DEBUG_OBJECT (bsink, "scaling to %dx%d", GST_VIDEO_SINK_WIDTH (av_sink),
+      GST_VIDEO_SINK_HEIGHT (av_sink));
+
+  av_sink->info = vinfo;
+
+  newpool = gst_video_buffer_pool_new ();
+  structure = gst_buffer_pool_get_config (newpool);
+  gst_buffer_pool_config_set_params (structure, caps, vinfo.size, 2, 0);
+  gst_buffer_pool_set_config (newpool, structure);
+
+  oldpool = av_sink->pool;
+  /* we don't activate the pool yet, this will be done by downstream after it
+   * has configured the pool. If downstream does not want our pool we will
+   * activate it when we render into it */
+  av_sink->pool = newpool;
+
+  /* unref the old sink */
+  if (oldpool) {
+    /* we don't deactivate, some elements might still be using it, it will
+     * be deactivated when the last ref is gone */
+    gst_object_unref (oldpool);
+  }
+
+  return TRUE;
+}
+
+static GstFlowReturn
+gst_av_sample_video_sink_prepare (GstBaseSink * bsink, GstBuffer * buf)
+{
+  GstAVSampleVideoSink *av_sink;
+
+  av_sink = GST_AV_SAMPLE_VIDEO_SINK (bsink);
+
+  GST_LOG_OBJECT (bsink, "preparing buffer:%p", buf);
+
+  if (GST_VIDEO_SINK_WIDTH (av_sink) < 1 ||
+      GST_VIDEO_SINK_HEIGHT (av_sink) < 1) {
+    return GST_FLOW_NOT_NEGOTIATED;
+  }
+
+  return GST_FLOW_OK;
+}
+
+static void
+_unmap_planar_frame (GstVideoFrame * v_frame, const void * data, gsize dataSize,
+    gsize numberOfPlanes, const void *planeAddressed[])
+{
+  GST_TRACE ("freeing video frame %p", v_frame);
+
+  gst_video_frame_unmap (v_frame);
+  g_free (v_frame);
+}
+
+static void
+_unmap_frame (GstVideoFrame * v_frame, const void * data)
+{
+  GST_TRACE ("freeing video frame %p", v_frame);
+
+  gst_video_frame_unmap (v_frame);
+  g_free (v_frame);
+}
+
+static GstFlowReturn
+gst_av_sample_video_sink_show_frame (GstVideoSink * vsink, GstBuffer * buf)
+{
+  GstAVSampleVideoSink *av_sink;
+  CVPixelBufferRef pbuf;
+  CMVideoFormatDescriptionRef v_format_desc;
+  GstVideoFrame *v_frame;
+  CMSampleTimingInfo sample_time;
+  __block CMSampleBufferRef sample_buf;
+  CFArrayRef sample_attachments;
+  gsize l, r, t, b;
+  gint i;
+
+  GST_TRACE_OBJECT (vsink, "rendering buffer:%p", buf);
+
+  av_sink = GST_AV_SAMPLE_VIDEO_SINK (vsink);
+
+  GST_TRACE_OBJECT (vsink, "redisplay of size:%ux%u, window size:%ux%u",
+      GST_VIDEO_INFO_WIDTH (&av_sink->info),
+      GST_VIDEO_INFO_HEIGHT (&av_sink->info),
+      GST_VIDEO_SINK_WIDTH (av_sink),
+      GST_VIDEO_SINK_HEIGHT (av_sink));
+
+  v_frame = g_new0 (GstVideoFrame, 1);
+
+  if (!gst_video_frame_map (v_frame, &av_sink->info, buf, GST_MAP_READ)) {
+    GST_ERROR_OBJECT (av_sink, "Failed to map input video frame");
+    g_free (v_frame);
+    return GST_FLOW_ERROR;
+  }
+
+  if (GST_VIDEO_INFO_N_PLANES (&v_frame->info) == 1) {
+    /* single plane */
+    if (kCVReturnSuccess != CVPixelBufferCreateWithBytes (NULL,
+        GST_VIDEO_INFO_WIDTH (&v_frame->info),
+        GST_VIDEO_INFO_HEIGHT (&v_frame->info),
+        _cv_pixel_format_type_from_video_format (GST_VIDEO_INFO_FORMAT (&v_frame->info)),
+        v_frame->data[0], v_frame->info.stride[0],
+        (CVPixelBufferReleaseBytesCallback) _unmap_frame, v_frame, NULL,
+        &pbuf)) {
+      GST_ERROR_OBJECT (av_sink, "Error creating Core Video pixel buffer");
+      gst_video_frame_unmap (v_frame);
+      g_free (v_frame);
+      return GST_FLOW_ERROR;
+    }
+  } else {
+    /* multi-planar */
+    gsize widths[GST_VIDEO_MAX_PLANES] = { 0, };
+    gsize heights[GST_VIDEO_MAX_PLANES] = { 0, };
+    gsize strides[GST_VIDEO_MAX_PLANES] = { 0, };
+    gint i;
+
+    for (i = 0; i < GST_VIDEO_INFO_N_PLANES (&v_frame->info); i++) {
+      widths[i] = GST_VIDEO_INFO_COMP_WIDTH (&v_frame->info, i);
+      heights[i] = GST_VIDEO_INFO_COMP_HEIGHT (&v_frame->info, i);
+      strides[i] = GST_VIDEO_INFO_COMP_STRIDE (&v_frame->info, i);
+    }
+
+    if (kCVReturnSuccess != CVPixelBufferCreateWithPlanarBytes (NULL,
+        GST_VIDEO_INFO_WIDTH (&v_frame->info),
+        GST_VIDEO_INFO_HEIGHT (&v_frame->info),
+        _cv_pixel_format_type_from_video_format (GST_VIDEO_INFO_FORMAT (&v_frame->info)),
+         /* have to put something for these two parameters otherwise
+          * the callback is not called resulting in a big leak */
+        v_frame, v_frame->info.size,
+        GST_VIDEO_INFO_N_PLANES (&v_frame->info), v_frame->data,
+        widths, heights, strides,
+        (CVPixelBufferReleasePlanarBytesCallback) _unmap_planar_frame,
+        v_frame, NULL, &pbuf)) {
+      GST_ERROR_OBJECT (av_sink, "Error creating Core Video pixel buffer");
+      gst_video_frame_unmap (v_frame);
+      g_free (v_frame);
+      return GST_FLOW_ERROR;
+    }
+  }
+
+  CVPixelBufferLockBaseAddress (pbuf, kCVPixelBufferLock_ReadOnly);
+
+  CVPixelBufferGetExtendedPixels (pbuf, &l, &r, &t, &b);
+
+  GST_TRACE_OBJECT (av_sink, "CVPixelBuffer n_planes %u width %u height %u"
+      " data size %" G_GSIZE_FORMAT " extra pixels l %u r %u t %u b %u",
+      (guint) CVPixelBufferGetPlaneCount (pbuf),
+      (guint) CVPixelBufferGetWidth (pbuf),
+      (guint) CVPixelBufferGetHeight (pbuf),
+      CVPixelBufferGetDataSize (pbuf),
+      (guint) l, (guint) r, (guint) t, (guint) b);
+
+  GST_TRACE_OBJECT (av_sink, "GstVideoFrame n_planes %u width %u height %u"
+      " data size %"G_GSIZE_FORMAT " extra pixels l %u r %u t %u b %u",
+      GST_VIDEO_INFO_N_PLANES (&v_frame->info),
+      GST_VIDEO_INFO_WIDTH (&v_frame->info),
+      GST_VIDEO_INFO_HEIGHT (&v_frame->info),
+      v_frame->info.size, 0, 0, 0, 0);
+
+  if (GST_VIDEO_INFO_N_PLANES (&v_frame->info) > 1) {
+    for (i = 0; i < GST_VIDEO_INFO_N_PLANES (&v_frame->info); i++) {
+      GST_TRACE_OBJECT (av_sink, "plane %i CVPixelBuffer width %u height %u "
+          "stride %u data %p", i,
+          (guint) CVPixelBufferGetWidthOfPlane (pbuf, i),
+          (guint) CVPixelBufferGetHeightOfPlane (pbuf, i),
+          (guint) CVPixelBufferGetBytesPerRowOfPlane (pbuf, i),
+          CVPixelBufferGetBaseAddressOfPlane (pbuf, i));
+      GST_TRACE_OBJECT (av_sink, "plane %i GstVideoFrame width %u height %u "
+          "stride %u data %p", i,
+          GST_VIDEO_INFO_COMP_WIDTH (&v_frame->info, i),
+          GST_VIDEO_INFO_COMP_HEIGHT (&v_frame->info, i),
+          GST_VIDEO_INFO_COMP_STRIDE (&v_frame->info, i),
+          CVPixelBufferGetBaseAddressOfPlane (pbuf, i));
+    }
+  } else {
+    GST_TRACE_OBJECT (av_sink, "CVPixelBuffer attrs stride %u data %p",
+      (guint) CVPixelBufferGetBytesPerRow (pbuf),
+      CVPixelBufferGetBaseAddress (pbuf));
+    GST_TRACE_OBJECT (av_sink, "GstVideoFrame attrs stride %u data %p",
+        v_frame->info.stride[0], v_frame->data[0]);
+  }
+
+  CVPixelBufferUnlockBaseAddress (pbuf, kCVPixelBufferLock_ReadOnly);
+
+  if (0 != CMVideoFormatDescriptionCreateForImageBuffer (kCFAllocatorDefault,
+        pbuf, &v_format_desc)) {
+    GST_ERROR_OBJECT (av_sink, "Failed to retreive video format from "
+        "pixel buffer");
+    CFRelease (pbuf);
+    return GST_FLOW_ERROR;
+  }
+
+  sample_time.duration = CMTimeMake (GST_BUFFER_DURATION (buf), GST_SECOND);
+  sample_time.presentationTimeStamp = CMTimeMake (GST_BUFFER_PTS (buf), GST_SECOND);
+  sample_time.decodeTimeStamp = kCMTimeInvalid;
+
+  if (0 != CMSampleBufferCreateForImageBuffer (kCFAllocatorDefault, pbuf, TRUE,
+        NULL, NULL, v_format_desc, &sample_time, &sample_buf)) {
+    GST_ERROR_OBJECT (av_sink, "Failed to create CMSampleBuffer from "
+        "CVImageBuffer");
+    CFRelease (v_format_desc);
+    CFRelease (pbuf);
+    return GST_FLOW_ERROR;
+  }
+  CFRelease (v_format_desc);
+
+  sample_attachments = CMSampleBufferGetSampleAttachmentsArray (sample_buf, TRUE);
+  for (i = 0; i < CFArrayGetCount (sample_attachments); i++) {
+    CFMutableDictionaryRef attachments =
+       (CFMutableDictionaryRef) CFArrayGetValueAtIndex (sample_attachments, i);
+    /* Until we slave the CoreMedia clock, just display everything ASAP */
+    CFDictionarySetValue (attachments, kCMSampleAttachmentKey_DisplayImmediately,
+        kCFBooleanTrue);
+  }
+
+  dispatch_sync (dispatch_get_main_queue (), ^{
+    if (av_sink->keep_aspect_ratio)
+      av_sink->layer.videoGravity = AVLayerVideoGravityResizeAspect;
+    else
+      av_sink->layer.videoGravity = AVLayerVideoGravityResize;
+    [av_sink->layer enqueueSampleBuffer:sample_buf];
+  });
+
+  CFRelease (pbuf);
+  CFRelease (sample_buf);
+
+  if ([av_sink->layer status] == AVQueuedSampleBufferRenderingStatusFailed) {
+    GST_ERROR_OBJECT (av_sink, "failed to enqueue buffer on layer, %s",
+        [[[av_sink->layer error] description] UTF8String]);
+    return GST_FLOW_ERROR;
+  }
+
+  return GST_FLOW_OK;
+}
+
+static gboolean
+gst_av_sample_video_sink_propose_allocation (GstBaseSink * bsink, GstQuery * query)
+{
+  GstAVSampleVideoSink *av_sink = GST_AV_SAMPLE_VIDEO_SINK (bsink);
+  GstBufferPool *pool;
+  GstStructure *config;
+  GstCaps *caps;
+  guint size;
+  gboolean need_pool;
+
+  gst_query_parse_allocation (query, &caps, &need_pool);
+
+  if (caps == NULL)
+    goto no_caps;
+
+  if ((pool = av_sink->pool))
+    gst_object_ref (pool);
+
+  if (pool != NULL) {
+    GstCaps *pcaps;
+
+    /* we had a pool, check caps */
+    GST_DEBUG_OBJECT (av_sink, "check existing pool caps");
+    config = gst_buffer_pool_get_config (pool);
+    gst_buffer_pool_config_get_params (config, &pcaps, &size, NULL, NULL);
+
+    if (!gst_caps_is_equal (caps, pcaps)) {
+      GST_DEBUG_OBJECT (av_sink, "pool has different caps");
+      /* different caps, we can't use this pool */
+      gst_object_unref (pool);
+      pool = NULL;
+    }
+    gst_structure_free (config);
+  }
+
+  if (pool == NULL && need_pool) {
+    GstVideoInfo info;
+
+    if (!gst_video_info_from_caps (&info, caps))
+      goto invalid_caps;
+
+    GST_DEBUG_OBJECT (av_sink, "create new pool");
+    pool = gst_video_buffer_pool_new ();
+
+    /* the normal size of a frame */
+    size = info.size;
+
+    config = gst_buffer_pool_get_config (pool);
+    gst_buffer_pool_config_set_params (config, caps, size, 0, 0);
+    if (!gst_buffer_pool_set_config (pool, config))
+      goto config_failed;
+  }
+  /* we need at least 2 buffer because we hold on to the last one */
+  if (pool) {
+    gst_query_add_allocation_pool (query, pool, size, 2, 0);
+    gst_object_unref (pool);
+  }
+
+  /* we also support various metadata */
+  gst_query_add_allocation_meta (query, GST_VIDEO_META_API_TYPE, 0);
+
+  return TRUE;
+
+  /* ERRORS */
+no_caps:
+  {
+    GST_DEBUG_OBJECT (bsink, "no caps specified");
+    return FALSE;
+  }
+invalid_caps:
+  {
+    GST_DEBUG_OBJECT (bsink, "invalid caps specified");
+    return FALSE;
+  }
+config_failed:
+  {
+    GST_DEBUG_OBJECT (bsink, "failed setting config");
+    return FALSE;
+  }
+}
diff --git a/sys/applemedia/plugin.m b/sys/applemedia/plugin.m
index 44ff3e4f6..fbf645ca6 100644
--- a/sys/applemedia/plugin.m
+++ b/sys/applemedia/plugin.m
@@ -30,6 +30,7 @@
 #ifdef HAVE_AVFOUNDATION
 #include "avfvideosrc.h"
 #include "avfassetsrc.h"
+#include "avsamplevideosink.h"
 #endif
 #ifdef HAVE_VIDEOTOOLBOX
 #include "vtdec.h"
@@ -77,6 +78,8 @@ plugin_init (GstPlugin * plugin)
       GST_TYPE_AVF_VIDEO_SRC);
   res &= gst_element_register (plugin, "avfassetsrc", AV_RANK,
       GST_TYPE_AVF_ASSET_SRC);
+  res &= gst_element_register (plugin, "avsamplebufferlayersink",
+      GST_RANK_NONE, GST_TYPE_AV_SAMPLE_VIDEO_SINK);
 #endif
 
   res &= gst_element_register (plugin, "atdec", GST_RANK_MARGINAL, GST_TYPE_ATDEC);
@@ -89,6 +92,7 @@ plugin_init (GstPlugin * plugin)
   }
 #endif
 
+
   return res;
 }