vaapipostproc: add new element for video postprocessing.

Add vaapipostproc element for video postprocessing. So far, only basic
bob deinterlacing is implemented. Interlaced mode is automatically
detected based on sink caps ("interlaced" field).

1 files changed, 714 insertions, 0 deletions

diff --git a/gst/vaapi/gstvaapipostproc.c b/gst/vaapi/gstvaapipostproc.c
new file mode 100644
index 00000000..e0f9f679
--- /dev/null
+++ b/gst/vaapi/gstvaapipostproc.c
@@ -0,0 +1,714 @@
+/*
+ *  gstvaapipostproc.c - VA-API video postprocessing
+ *
+ *  Copyright (C) 2012 Intel Corporation
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public License
+ *  as published by the Free Software Foundation; either version 2.1
+ *  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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free
+ *  Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA 02110-1301 USA
+ */
+
+/**
+ * SECTION:gstvaapipostproc
+ * @short_description: A video postprocessing filter
+ *
+ * vaapipostproc consists in various postprocessing algorithms to be
+ * applied to VA surfaces. So far, only basic bob deinterlacing is
+ * implemented.
+ */
+
+#include "config.h"
+#include <gst/video/video.h>
+#include <gst/video/videocontext.h>
+#include <gst/vaapi/gstvaapivideosink.h>
+#include <gst/vaapi/gstvaapivideobuffer.h>
+
+#include "gstvaapipluginutil.h"
+#include "gstvaapipostproc.h"
+
+#define GST_PLUGIN_NAME "vaapipostproc"
+#define GST_PLUGIN_DESC "A video postprocessing filter"
+
+GST_DEBUG_CATEGORY_STATIC(gst_debug_vaapipostproc);
+#define GST_CAT_DEFAULT gst_debug_vaapipostproc
+
+/* ElementFactory information */
+static const GstElementDetails gst_vaapipostproc_details =
+    GST_ELEMENT_DETAILS(
+        "VA-API video postprocessing",
+        "Filter/Converter/Video",
+        GST_PLUGIN_DESC,
+        "Gwenole Beauchesne <gwenole.beauchesne@intel.com>");
+
+/* Default templates */
+static const char gst_vaapipostproc_sink_caps_str[] =
+    GST_VAAPI_SURFACE_CAPS ", "
+    "interlaced = (boolean) { true, false }";
+
+static const char gst_vaapipostproc_src_caps_str[] =
+    GST_VAAPI_SURFACE_CAPS ", "
+    "interlaced = (boolean) false";
+
+static GstStaticPadTemplate gst_vaapipostproc_sink_factory =
+    GST_STATIC_PAD_TEMPLATE(
+        "sink",
+        GST_PAD_SINK,
+        GST_PAD_ALWAYS,
+        GST_STATIC_CAPS(gst_vaapipostproc_sink_caps_str));
+
+static GstStaticPadTemplate gst_vaapipostproc_src_factory =
+    GST_STATIC_PAD_TEMPLATE(
+        "src",
+        GST_PAD_SRC,
+        GST_PAD_ALWAYS,
+        GST_STATIC_CAPS(gst_vaapipostproc_src_caps_str));
+
+#define GstVideoContextClass GstVideoContextInterface
+GST_BOILERPLATE_WITH_INTERFACE(
+    GstVaapiPostproc,
+    gst_vaapipostproc,
+    GstElement,
+    GST_TYPE_ELEMENT,
+    GstVideoContext,
+    GST_TYPE_VIDEO_CONTEXT,
+    gst_video_context);
+
+enum {
+    PROP_0,
+
+    PROP_DEINTERLACE_MODE,
+    PROP_DEINTERLACE_METHOD,
+};
+
+#define DEFAULT_DEINTERLACE_MODE        GST_VAAPI_DEINTERLACE_MODE_AUTO
+#define DEFAULT_DEINTERLACE_METHOD      GST_VAAPI_DEINTERLACE_METHOD_BOB
+
+#define GST_TYPE_VAAPI_DEINTERLACE_MODES \
+    gst_vaapi_deinterlace_modes_get_type()
+
+static GType
+gst_vaapi_deinterlace_modes_get_type(void)
+{
+    static GType deinterlace_modes_type = 0;
+
+    static const GEnumValue modes_types[] = {
+        { GST_VAAPI_DEINTERLACE_MODE_AUTO,
+          "Auto detection", "auto" },
+        { GST_VAAPI_DEINTERLACE_MODE_INTERLACED,
+          "Force deinterlacing", "interlaced" },
+        { GST_VAAPI_DEINTERLACE_MODE_DISABLED,
+          "Never deinterlace", "disabled" },
+        { 0, NULL, NULL },
+    };
+
+    if (!deinterlace_modes_type) {
+        deinterlace_modes_type =
+            g_enum_register_static("GstVaapiDeinterlaceModes", modes_types);
+    }
+    return deinterlace_modes_type;
+}
+
+#define GST_TYPE_VAAPI_DEINTERLACE_METHODS \
+    gst_vaapi_deinterlace_methods_get_type()
+
+static GType
+gst_vaapi_deinterlace_methods_get_type(void)
+{
+    static GType deinterlace_methods_type = 0;
+
+    static const GEnumValue methods_types[] = {
+        { GST_VAAPI_DEINTERLACE_METHOD_BOB,
+          "Bob deinterlacing", "bob" },
+#if 0
+        /* VA/VPP */
+        { GST_VAAPI_DEINTERLACE_METHOD_WEAVE,
+          "Weave deinterlacing", "weave" },
+        { GST_VAAPI_DEINTERLACE_METHOD_MOTION_ADAPTIVE,
+          "Motion adaptive deinterlacing", "motion-adaptive" },
+        { GST_VAAPI_DEINTERLACE_METHOD_MOTION_COMPENSATED,
+          "Motion compensated deinterlacing", "motion-compensated" },
+#endif
+        { 0, NULL, NULL },
+    };
+
+    if (!deinterlace_methods_type) {
+        deinterlace_methods_type =
+            g_enum_register_static("GstVaapiDeinterlaceMethods", methods_types);
+    }
+    return deinterlace_methods_type;
+}
+
+static inline GstVaapiPostproc *
+get_vaapipostproc_from_pad(GstPad *pad)
+{
+    return GST_VAAPIPOSTPROC(gst_pad_get_parent_element(pad));
+}
+
+/* GstVideoContext interface */
+
+static void
+gst_vaapipostproc_set_video_context(
+    GstVideoContext *context,
+    const gchar     *type,
+    const GValue    *value
+)
+{
+    GstVaapiPostproc * const postproc = GST_VAAPIPOSTPROC(context);
+
+    gst_vaapi_set_display(type, value, &postproc->display);
+}
+
+static gboolean
+gst_video_context_supported(GstVaapiPostproc *postproc, GType iface_type)
+{
+    return (iface_type == GST_TYPE_VIDEO_CONTEXT);
+}
+
+static void
+gst_video_context_interface_init(GstVideoContextInterface *iface)
+{
+    iface->set_context = gst_vaapipostproc_set_video_context;
+}
+
+static gboolean
+gst_vaapipostproc_create(GstVaapiPostproc *postproc, GstCaps *caps)
+{
+    if (!gst_vaapi_ensure_display(postproc, &postproc->display))
+        return FALSE;
+
+    gst_caps_replace(&postproc->postproc_caps, caps);
+    return TRUE;
+}
+
+static void
+gst_vaapipostproc_destroy(GstVaapiPostproc *postproc)
+{
+    gst_caps_replace(&postproc->postproc_caps, NULL);
+
+    if (postproc->display) {
+        g_object_unref(postproc->display);
+        postproc->display = NULL;
+    }
+}
+
+static gboolean
+gst_vaapipostproc_reset(GstVaapiPostproc *postproc, GstCaps *caps)
+{
+    if (postproc->postproc_caps &&
+        gst_caps_is_always_compatible(caps, postproc->postproc_caps))
+        return TRUE;
+
+    gst_vaapipostproc_destroy(postproc);
+    return gst_vaapipostproc_create(postproc, caps);
+}
+
+static gboolean
+gst_vaapipostproc_start(GstVaapiPostproc *postproc)
+{
+    if (!gst_vaapi_ensure_display(postproc, &postproc->display))
+        return FALSE;
+    return TRUE;
+}
+
+static gboolean
+gst_vaapipostproc_stop(GstVaapiPostproc *postproc)
+{
+    if (postproc->display) {
+        g_object_unref(postproc->display);
+        postproc->display = NULL;
+    }
+    return TRUE;
+}
+
+static GstFlowReturn
+gst_vaapipostproc_process(GstVaapiPostproc *postproc, GstBuffer *buf)
+{
+    GstVaapiVideoBuffer *vbuf = GST_VAAPI_VIDEO_BUFFER(buf);
+    GstVaapiSurfaceProxy *proxy;
+    GstClockTime timestamp;
+    GstFlowReturn ret;
+    GstBuffer *outbuf = NULL;
+    guint outbuf_flags, flags = 0;
+    gboolean tff;
+
+    /* Deinterlacing disabled, push frame */
+    if (!postproc->deinterlace) {
+        gst_vaapi_video_buffer_set_render_flags(vbuf, flags);
+        ret = gst_pad_push(postproc->srcpad, buf);
+        if (ret != GST_FLOW_OK)
+            goto error_push_buffer;
+        return GST_FLOW_OK;
+    }
+
+    timestamp = GST_BUFFER_TIMESTAMP(buf);
+    proxy     = gst_vaapi_video_buffer_get_surface_proxy(vbuf);
+    tff       = gst_vaapi_surface_proxy_get_tff(proxy);
+
+    /* First field */
+    outbuf = gst_vaapi_video_buffer_new_with_surface_proxy(proxy);
+    if (!outbuf)
+        goto error_create_buffer;
+
+    vbuf = GST_VAAPI_VIDEO_BUFFER(outbuf);
+    outbuf_flags = flags;
+    outbuf_flags |= tff ?
+        GST_VAAPI_PICTURE_STRUCTURE_TOP_FIELD :
+        GST_VAAPI_PICTURE_STRUCTURE_BOTTOM_FIELD;
+    gst_vaapi_video_buffer_set_render_flags(vbuf, outbuf_flags);
+
+    GST_BUFFER_TIMESTAMP(outbuf) = timestamp;
+    GST_BUFFER_DURATION(outbuf)  = postproc->field_duration;
+    gst_buffer_set_caps(outbuf, postproc->srcpad_caps);
+    ret = gst_pad_push(postproc->srcpad, outbuf);
+    if (ret != GST_FLOW_OK)
+        goto error_push_buffer;
+
+    /* Second field */
+    outbuf = gst_vaapi_video_buffer_new_with_surface_proxy(proxy);
+    if (!outbuf)
+        goto error_create_buffer;
+
+    vbuf = GST_VAAPI_VIDEO_BUFFER(outbuf);
+    outbuf_flags = flags;
+    outbuf_flags |= tff ?
+        GST_VAAPI_PICTURE_STRUCTURE_BOTTOM_FIELD :
+        GST_VAAPI_PICTURE_STRUCTURE_TOP_FIELD;
+    gst_vaapi_video_buffer_set_render_flags(vbuf, outbuf_flags);
+
+    GST_BUFFER_TIMESTAMP(outbuf) = timestamp + postproc->field_duration;
+    GST_BUFFER_DURATION(outbuf)  = postproc->field_duration;
+    gst_buffer_set_caps(outbuf, postproc->srcpad_caps);
+    ret = gst_pad_push(postproc->srcpad, outbuf);
+    if (ret != GST_FLOW_OK)
+        goto error_push_buffer;
+
+    gst_buffer_unref(buf);
+    return GST_FLOW_OK;
+
+    /* ERRORS */
+error_create_buffer:
+    {
+        GST_ERROR("failed to create output buffer");
+        gst_buffer_unref(buf);
+        return GST_FLOW_UNEXPECTED;
+    }
+error_push_buffer:
+    {
+        if (ret != GST_FLOW_WRONG_STATE)
+            GST_ERROR("failed to push output buffer to video sink");
+        gst_buffer_unref(buf);
+        return GST_FLOW_UNEXPECTED;
+    }
+}
+
+static gboolean
+gst_vaapipostproc_update_sink_caps(GstVaapiPostproc *postproc, GstCaps *caps)
+{
+    gint fps_n, fps_d;
+    gboolean interlaced;
+
+    if (!gst_video_parse_caps_framerate(caps, &fps_n, &fps_d))
+        return FALSE;
+    postproc->fps_n = fps_n;
+    postproc->fps_d = fps_d;
+
+    switch (postproc->deinterlace_mode) {
+    case GST_VAAPI_DEINTERLACE_MODE_AUTO:
+        if (!gst_video_format_parse_caps_interlaced(caps, &interlaced))
+            return FALSE;
+        postproc->deinterlace = interlaced;
+        break;
+    case GST_VAAPI_DEINTERLACE_MODE_INTERLACED:
+        postproc->deinterlace = TRUE;
+        break;
+    case GST_VAAPI_DEINTERLACE_MODE_DISABLED:
+        postproc->deinterlace = FALSE;
+        break;
+    }
+
+    postproc->field_duration = gst_util_uint64_scale(
+        GST_SECOND,
+        postproc->fps_d,
+        (1 + postproc->deinterlace) * postproc->fps_n
+    );
+
+    gst_caps_replace(&postproc->sinkpad_caps, caps);
+    return TRUE;
+}
+
+static gboolean
+gst_vaapipostproc_update_src_caps(GstVaapiPostproc *postproc, GstCaps *caps)
+{
+    GstCaps *src_caps;
+    GstStructure *structure;
+    const GValue *v_width, *v_height, *v_par;
+    gint fps_n, fps_d;
+
+    if (postproc->srcpad_caps)
+        src_caps = gst_caps_make_writable(postproc->srcpad_caps);
+    else
+        src_caps = gst_caps_from_string(GST_VAAPI_SURFACE_CAPS_NAME);
+    if (!src_caps)
+        return FALSE;
+    postproc->srcpad_caps = src_caps;
+
+    structure    = gst_caps_get_structure(caps, 0);
+    v_width      = gst_structure_get_value(structure, "width");
+    v_height     = gst_structure_get_value(structure, "height");
+    v_par        = gst_structure_get_value(structure, "pixel-aspect-ratio");
+
+    structure = gst_caps_get_structure(src_caps, 0);
+    if (v_width && v_height) {
+        gst_structure_set_value(structure, "width", v_width);
+        gst_structure_set_value(structure, "height", v_height);
+    }
+    if (v_par)
+        gst_structure_set_value(structure, "pixel-aspect-ratio", v_par);
+
+    gst_structure_set(structure, "type", G_TYPE_STRING, "vaapi", NULL);
+    gst_structure_set(structure, "opengl", G_TYPE_BOOLEAN, USE_VAAPI_GLX, NULL);
+
+    if (!postproc->deinterlace)
+        gst_structure_remove_field(structure, "interlaced");
+    else {
+        /* Set double framerate in interlaced mode */
+        if (!gst_util_fraction_multiply(postproc->fps_n, postproc->fps_d,
+                                        2, 1,
+                                        &fps_n, &fps_d))
+            return FALSE;
+
+        gst_structure_set(
+            structure,
+            "interlaced", G_TYPE_BOOLEAN, FALSE,
+            "framerate", GST_TYPE_FRACTION, fps_n, fps_d,
+            NULL
+        );
+    }
+    return gst_pad_set_caps(postproc->srcpad, src_caps);
+}
+
+static gboolean
+gst_vaapipostproc_ensure_allowed_caps(GstVaapiPostproc *postproc)
+{
+    if (postproc->allowed_caps)
+        return TRUE;
+
+    postproc->allowed_caps =
+        gst_caps_from_string(gst_vaapipostproc_sink_caps_str);
+    if (!postproc->allowed_caps)
+        return FALSE;
+
+    /* XXX: append VA/VPP filters */
+    return TRUE;
+}
+
+static GstCaps *
+gst_vaapipostproc_get_caps(GstPad *pad)
+{
+    GstVaapiPostproc * const postproc = get_vaapipostproc_from_pad(pad);
+    GstCaps *out_caps;
+
+    if (gst_vaapipostproc_ensure_allowed_caps(postproc))
+        out_caps = gst_caps_ref(postproc->allowed_caps);
+    else
+        out_caps = gst_caps_new_empty();
+
+    gst_object_unref(postproc);
+    return out_caps;
+}
+
+static gboolean
+gst_vaapipostproc_set_caps(GstPad *pad, GstCaps *caps)
+{
+    GstVaapiPostproc * const postproc = get_vaapipostproc_from_pad(pad);
+    gboolean success = FALSE;
+
+    g_return_val_if_fail(pad == postproc->sinkpad, FALSE);
+
+    do {
+        if (!gst_vaapipostproc_update_sink_caps(postproc, caps))
+            break;
+        if (!gst_vaapipostproc_update_src_caps(postproc, caps))
+            break;
+        if (!gst_vaapipostproc_reset(postproc, postproc->sinkpad_caps))
+            break;
+        success = TRUE;
+    } while (0);
+    gst_object_unref(postproc);
+    return success;
+}
+
+static GstFlowReturn
+gst_vaapipostproc_chain(GstPad *pad, GstBuffer *buf)
+{
+    GstVaapiPostproc * const postproc = get_vaapipostproc_from_pad(pad);
+    GstFlowReturn ret;
+
+    ret = gst_vaapipostproc_process(postproc, buf);
+    gst_object_unref(postproc);
+    return ret;
+}
+
+static gboolean
+gst_vaapipostproc_sink_event(GstPad *pad, GstEvent *event)
+{
+    GstVaapiPostproc * const postproc = get_vaapipostproc_from_pad(pad);
+    gboolean success;
+
+    GST_DEBUG("handle sink event '%s'", GST_EVENT_TYPE_NAME(event));
+
+    /* Propagate event downstream */
+    success = gst_pad_push_event(postproc->srcpad, event);
+    gst_object_unref(postproc);
+    return success;
+}
+
+static gboolean
+gst_vaapipostproc_src_event(GstPad *pad, GstEvent *event)
+{
+    GstVaapiPostproc * const postproc = get_vaapipostproc_from_pad(pad);
+    gboolean success;
+
+    GST_DEBUG("handle src event '%s'", GST_EVENT_TYPE_NAME(event));
+
+    /* Propagate event upstream */
+    success = gst_pad_push_event(postproc->sinkpad, event);
+    gst_object_unref(postproc);
+    return success;
+}
+
+static gboolean
+gst_vaapipostproc_query(GstPad *pad, GstQuery *query)
+{
+    GstVaapiPostproc * const postproc = get_vaapipostproc_from_pad(pad);
+    gboolean success;
+
+    GST_DEBUG("sharing display %p", postproc->display);
+
+    if (gst_vaapi_reply_to_query(query, postproc->display))
+        success = TRUE;
+    else
+        success = gst_pad_query_default(pad, query);
+
+    gst_object_unref(postproc);
+    return success;
+}
+
+static void
+gst_vaapipostproc_finalize(GObject *object)
+{
+    GstVaapiPostproc * const postproc = GST_VAAPIPOSTPROC(object);
+
+    gst_vaapipostproc_destroy(postproc);
+
+    gst_caps_replace(&postproc->sinkpad_caps, NULL);
+    gst_caps_replace(&postproc->srcpad_caps,  NULL);
+    gst_caps_replace(&postproc->allowed_caps, NULL);
+
+    G_OBJECT_CLASS(parent_class)->finalize(object);
+}
+
+static void
+gst_vaapipostproc_set_property(
+    GObject      *object,
+    guint         prop_id,
+    const GValue *value,
+    GParamSpec   *pspec
+)
+{
+    GstVaapiPostproc * const postproc = GST_VAAPIPOSTPROC(object);
+
+    switch (prop_id) {
+    case PROP_DEINTERLACE_MODE:
+        postproc->deinterlace_mode = g_value_get_enum(value);
+        break;
+    case PROP_DEINTERLACE_METHOD:
+        postproc->deinterlace_method = g_value_get_enum(value);
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+        break;
+    }
+}
+
+static void
+gst_vaapipostproc_get_property(
+    GObject    *object,
+    guint       prop_id,
+    GValue     *value,
+    GParamSpec *pspec
+)
+{
+    GstVaapiPostproc * const postproc = GST_VAAPIPOSTPROC(object);
+
+    switch (prop_id) {
+    case PROP_DEINTERLACE_MODE:
+        g_value_set_enum(value, postproc->deinterlace_mode);
+        break;
+    case PROP_DEINTERLACE_METHOD:
+        g_value_set_enum(value, postproc->deinterlace_method);
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+        break;
+    }
+}
+
+static GstStateChangeReturn
+gst_vaapipostproc_change_state(GstElement *element, GstStateChange transition)
+{
+    GstVaapiPostproc * const postproc = GST_VAAPIPOSTPROC(element);
+    GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
+
+    switch (transition) {
+    case GST_STATE_CHANGE_NULL_TO_READY:
+        if (!gst_vaapipostproc_start(postproc))
+            return GST_STATE_CHANGE_FAILURE;
+        break;
+    case GST_STATE_CHANGE_READY_TO_PAUSED:
+        break;
+    case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
+        break;
+    default:
+        break;
+    }
+
+    ret = GST_ELEMENT_CLASS(parent_class)->change_state(element, transition);
+    if (ret != GST_STATE_CHANGE_SUCCESS)
+        return ret;
+
+    switch (transition) {
+    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
+        break;
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+        break;
+    case GST_STATE_CHANGE_READY_TO_NULL:
+        if (!gst_vaapipostproc_stop(postproc))
+            return GST_STATE_CHANGE_FAILURE;
+        break;
+    default:
+        break;
+    }
+    return GST_STATE_CHANGE_SUCCESS;
+}
+
+static void
+gst_vaapipostproc_class_init(GstVaapiPostprocClass *klass)
+{
+    GObjectClass * const object_class = G_OBJECT_CLASS(klass);
+    GstElementClass * const element_class = GST_ELEMENT_CLASS(klass);
+
+    GST_DEBUG_CATEGORY_INIT(gst_debug_vaapipostproc,
+                            GST_PLUGIN_NAME, 0, GST_PLUGIN_DESC);
+
+    object_class->finalize      = gst_vaapipostproc_finalize;
+    object_class->set_property  = gst_vaapipostproc_set_property;
+    object_class->get_property  = gst_vaapipostproc_get_property;
+
+    element_class->change_state = gst_vaapipostproc_change_state;
+
+    /**
+     * GstVaapiSink:deinterlace-mode:
+     *
+     * This selects whether the deinterlacing should always be applied or if
+     * they should only be applied on content that has the "interlaced" flag
+     * on the caps.
+     */
+    g_object_class_install_property
+        (object_class,
+         PROP_DEINTERLACE_MODE,
+         g_param_spec_enum("deinterlace",
+                           "Deinterlace",
+                           "Deinterlace mode to use",
+                           GST_TYPE_VAAPI_DEINTERLACE_MODES,
+                           DEFAULT_DEINTERLACE_MODE,
+                           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+    /**
+     * GstVaapiSink:deinterlace-method:
+     *
+     * This selects the deinterlacing method to apply.
+     */
+    g_object_class_install_property
+        (object_class,
+         PROP_DEINTERLACE_METHOD,
+         g_param_spec_enum("deinterlace-method",
+                           "Deinterlace method",
+                           "Deinterlace method to use",
+                           GST_TYPE_VAAPI_DEINTERLACE_METHODS,
+                           DEFAULT_DEINTERLACE_METHOD,
+                           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+}
+
+static void
+gst_vaapipostproc_base_init(gpointer klass)
+{
+    GstElementClass * const element_class = GST_ELEMENT_CLASS(klass);
+    GstPadTemplate *pad_template;
+
+    gst_element_class_set_details(element_class, &gst_vaapipostproc_details);
+
+    /* sink pad */
+    pad_template = gst_static_pad_template_get(&gst_vaapipostproc_sink_factory);
+    gst_element_class_add_pad_template(element_class, pad_template);
+    gst_object_unref(pad_template);
+
+    /* src pad */
+    pad_template = gst_static_pad_template_get(&gst_vaapipostproc_src_factory);
+    gst_element_class_add_pad_template(element_class, pad_template);
+    gst_object_unref(pad_template);
+}
+
+static void
+gst_vaapipostproc_init(GstVaapiPostproc *postproc, GstVaapiPostprocClass *klass)
+{
+    GstElementClass * const element_class = GST_ELEMENT_CLASS(klass);
+
+    postproc->allowed_caps              = NULL;
+    postproc->postproc_caps             = NULL;
+    postproc->display                   = NULL;
+    postproc->surface_width             = 0;
+    postproc->surface_height            = 0;
+    postproc->deinterlace               = FALSE;
+    postproc->deinterlace_mode          = DEFAULT_DEINTERLACE_MODE;
+    postproc->deinterlace_method        = DEFAULT_DEINTERLACE_METHOD;
+    postproc->field_duration            = GST_CLOCK_TIME_NONE;
+    postproc->fps_n                     = 0;
+    postproc->fps_d                     = 0;
+
+    /* Pad through which data comes in to the element */
+    postproc->sinkpad = gst_pad_new_from_template(
+        gst_element_class_get_pad_template(element_class, "sink"),
+        "sink"
+    );
+    postproc->sinkpad_caps = NULL;
+
+    gst_pad_set_getcaps_function(postproc->sinkpad, gst_vaapipostproc_get_caps);
+    gst_pad_set_setcaps_function(postproc->sinkpad, gst_vaapipostproc_set_caps);
+    gst_pad_set_chain_function(postproc->sinkpad, gst_vaapipostproc_chain);
+    gst_pad_set_event_function(postproc->sinkpad, gst_vaapipostproc_sink_event);
+    gst_pad_set_query_function(postproc->sinkpad, gst_vaapipostproc_query);
+    gst_element_add_pad(GST_ELEMENT(postproc), postproc->sinkpad);
+
+    /* Pad through which data goes out of the element */
+    postproc->srcpad = gst_pad_new_from_template(
+        gst_element_class_get_pad_template(element_class, "src"),
+        "src"
+    );
+    postproc->srcpad_caps = NULL;
+
+    gst_pad_set_event_function(postproc->srcpad, gst_vaapipostproc_src_event);
+    gst_pad_set_query_function(postproc->srcpad, gst_vaapipostproc_query);
+    gst_element_add_pad(GST_ELEMENT(postproc), postproc->srcpad);
+}