gstreamer/gst/deinterlace/gstdeinterlace.c

/*
 * GStreamer
 * Copyright (C) 2005 Martin Eikermann <meiker@upb.de>
 * Copyright (C) 2008-2010 Sebastian Dröge <slomo@collabora.co.uk>
 * Copyright (C) 2011 Robert Swain <robert.swain@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.
 */

/**
 * SECTION:element-deinterlace
 *
 * deinterlace deinterlaces interlaced video frames to progressive video frames.
 * For this different algorithms can be selected which will be described later.
 *
 * <refsect2>
 * <title>Example launch line</title>
 * |[
 * gst-launch -v filesrc location=/path/to/file ! decodebin2 ! ffmpegcolorspace ! deinterlace ! ffmpegcolorspace ! autovideosink
 * ]| This pipeline deinterlaces a video file with the default deinterlacing options.
 * </refsect2>
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "gstdeinterlace.h"
#include "tvtime/plugins.h"

#include <string.h>

#if HAVE_ORC
#include <orc/orc.h>
#endif

GST_DEBUG_CATEGORY_STATIC (deinterlace_debug);
#define GST_CAT_DEFAULT (deinterlace_debug)

/* Properties */

#define DEFAULT_MODE            GST_DEINTERLACE_MODE_AUTO
#define DEFAULT_METHOD          GST_DEINTERLACE_LINEAR
#define DEFAULT_FIELDS          GST_DEINTERLACE_ALL
#define DEFAULT_FIELD_LAYOUT    GST_DEINTERLACE_LAYOUT_AUTO
#define DEFAULT_LOCKING         GST_DEINTERLACE_LOCKING_NONE
#define DEFAULT_IGNORE_OBSCURE  TRUE
#define DEFAULT_DROP_ORPHANS    TRUE

enum
{
  PROP_0,
  PROP_MODE,
  PROP_METHOD,
  PROP_FIELDS,
  PROP_FIELD_LAYOUT,
  PROP_LOCKING,
  PROP_IGNORE_OBSCURE,
  PROP_DROP_ORPHANS,
  PROP_LAST
};

#define GST_DEINTERLACE_BUFFER_STATE_P    (1<<0)
#define GST_DEINTERLACE_BUFFER_STATE_I    (1<<1)
#define GST_DEINTERLACE_BUFFER_STATE_TC_B (1<<2)
#define GST_DEINTERLACE_BUFFER_STATE_TC_T (1<<3)
#define GST_DEINTERLACE_BUFFER_STATE_TC_P (1<<4)
#define GST_DEINTERLACE_BUFFER_STATE_TC_M (1<<5)
#define GST_DEINTERLACE_BUFFER_STATE_DROP (1<<6)

#define GST_ONE \
  (GST_DEINTERLACE_BUFFER_STATE_TC_T | GST_DEINTERLACE_BUFFER_STATE_TC_B)
#define GST_PRG \
  (GST_DEINTERLACE_BUFFER_STATE_P | GST_DEINTERLACE_BUFFER_STATE_TC_P)
#define GST_INT \
  (GST_DEINTERLACE_BUFFER_STATE_I | GST_DEINTERLACE_BUFFER_STATE_TC_M)
#define GST_DRP (GST_DEINTERLACE_BUFFER_STATE_DROP)

#define GST_DEINTERLACE_OBSCURE_THRESHOLD 5

static const TelecinePattern telecine_patterns[] = {
  /* 60i -> 60p or 50i -> 50p (NOTE THE WEIRD RATIOS) */
  {"1:1", 1, 2, 1, {GST_ONE,}},
  /* 60i -> 30p or 50i -> 25p */
  {"2:2", 1, 1, 1, {GST_INT,}},
  /* 60i telecine -> 24p */
  {"2:3", 5, 4, 5, {GST_PRG, GST_PRG, GST_ONE, GST_ONE, GST_PRG,}},
  {"3:2:2:3", 5, 4, 5, {GST_PRG, GST_ONE, GST_INT, GST_ONE, GST_PRG,}},
  {"2:3:3:2", 5, 4, 5, {GST_PRG, GST_PRG, GST_DRP, GST_PRG, GST_PRG,}},

  /* The following patterns are obscure and are ignored if ignore-obscure is
   * set to true. If any patterns are added above this line, check and edit
   * GST_DEINTERLACE_OBSCURE_THRESHOLD */

  /* 50i Euro pulldown -> 24p */
  {"2-11:3", 25, 24, 25, {GST_PRG, GST_PRG, GST_PRG, GST_PRG, GST_PRG,
              GST_PRG, GST_PRG, GST_PRG, GST_PRG, GST_PRG,
              GST_PRG, GST_PRG, GST_ONE, GST_INT, GST_INT,
              GST_INT, GST_INT, GST_INT, GST_INT, GST_INT,
          GST_INT, GST_INT, GST_INT, GST_ONE, GST_PRG,}},
  /* 60i (NTSC 30000/1001) -> 16p (16000/1001) */
  {"3:4-3", 15, 8, 15, {GST_PRG, GST_DRP, GST_PRG, GST_DRP, GST_PRG,
              GST_DRP, GST_PRG, GST_DRP, GST_PRG, GST_DRP,
          GST_PRG, GST_DRP, GST_PRG, GST_DRP, GST_PRG,}},
  /* 50i (PAL) -> 16p */
  {"3-7:4", 25, 16, 25, {GST_PRG, GST_DRP, GST_PRG, GST_PRG, GST_DRP,
              GST_PRG, GST_PRG, GST_DRP, GST_PRG, GST_PRG,
              GST_DRP, GST_PRG, GST_DRP, GST_PRG, GST_PRG,
              GST_DRP, GST_PRG, GST_PRG, GST_DRP, GST_PRG,
          GST_PRG, GST_DRP, GST_PRG, GST_PRG, GST_DRP,}},
  /* NTSC 60i -> 18p */
  {"3:3:4", 5, 3, 5, {GST_PRG, GST_DRP, GST_PRG, GST_DRP, GST_PRG,}},
  /* NTSC 60i -> 20p */
  {"3:3", 3, 2, 3, {GST_PRG, GST_DRP, GST_PRG,}},
  /* NTSC 60i -> 27.5 */
  {"3:2-4", 11, 10, 11, {GST_PRG, GST_PRG, GST_PRG, GST_PRG, GST_PRG,
              GST_PRG, GST_ONE, GST_INT, GST_INT, GST_INT,
          GST_ONE,}},
  /* PAL 50i -> 27.5 */
  {"1:2-4", 9, 9, 10, {GST_PRG, GST_PRG, GST_PRG, GST_PRG, GST_INT,
          GST_INT, GST_INT, GST_INT, GST_INT,}},
};

static const GEnumValue methods_types[] = {
  {GST_DEINTERLACE_TOMSMOCOMP, "Motion Adaptive: Motion Search",
      "tomsmocomp"},
  {GST_DEINTERLACE_GREEDY_H, "Motion Adaptive: Advanced Detection",
      "greedyh"},
  {GST_DEINTERLACE_GREEDY_L, "Motion Adaptive: Simple Detection", "greedyl"},
  {GST_DEINTERLACE_VFIR, "Blur Vertical", "vfir"},
  {GST_DEINTERLACE_LINEAR, "Television: Full resolution", "linear"},
  {GST_DEINTERLACE_LINEAR_BLEND, "Blur: Temporal (Do Not Use)",
      "linearblend"},
  {GST_DEINTERLACE_SCALER_BOB, "Double lines", "scalerbob"},
  {GST_DEINTERLACE_WEAVE, "Weave (Do Not Use)", "weave"},
  {GST_DEINTERLACE_WEAVE_TFF, "Progressive: Top Field First (Do Not Use)",
      "weavetff"},
  {GST_DEINTERLACE_WEAVE_BFF, "Progressive: Bottom Field First (Do Not Use)",
      "weavebff"},
  {0, NULL, NULL},
};

static const GEnumValue locking_types[] = {
  {GST_DEINTERLACE_LOCKING_NONE,
      "No pattern locking", "none"},
  {GST_DEINTERLACE_LOCKING_AUTO,
        "Choose passive/active locking depending on whether upstream is live",
      "auto"},
  {GST_DEINTERLACE_LOCKING_ACTIVE,
        "Block until pattern-locked. Use accurate timestamp interpolation within a pattern repeat.",
      "active"},
  {GST_DEINTERLACE_LOCKING_PASSIVE,
        "Do not block. Use naïve timestamp adjustment until pattern-locked based on state history.",
      "passive"},
  {0, NULL, NULL},
};


#define GST_TYPE_DEINTERLACE_METHODS (gst_deinterlace_methods_get_type ())
static GType
gst_deinterlace_methods_get_type (void)
{
  static GType deinterlace_methods_type = 0;

  if (!deinterlace_methods_type) {
    deinterlace_methods_type =
        g_enum_register_static ("GstDeinterlaceMethods", methods_types);
  }
  return deinterlace_methods_type;
}

#define GST_TYPE_DEINTERLACE_FIELDS (gst_deinterlace_fields_get_type ())
static GType
gst_deinterlace_fields_get_type (void)
{
  static GType deinterlace_fields_type = 0;

  static const GEnumValue fields_types[] = {
    {GST_DEINTERLACE_ALL, "All fields", "all"},
    {GST_DEINTERLACE_TF, "Top fields only", "top"},
    {GST_DEINTERLACE_BF, "Bottom fields only", "bottom"},
    {0, NULL, NULL},
  };

  if (!deinterlace_fields_type) {
    deinterlace_fields_type =
        g_enum_register_static ("GstDeinterlaceFields", fields_types);
  }
  return deinterlace_fields_type;
}

#define GST_TYPE_DEINTERLACE_FIELD_LAYOUT (gst_deinterlace_field_layout_get_type ())
static GType
gst_deinterlace_field_layout_get_type (void)
{
  static GType deinterlace_field_layout_type = 0;

  static const GEnumValue field_layout_types[] = {
    {GST_DEINTERLACE_LAYOUT_AUTO, "Auto detection", "auto"},
    {GST_DEINTERLACE_LAYOUT_TFF, "Top field first", "tff"},
    {GST_DEINTERLACE_LAYOUT_BFF, "Bottom field first", "bff"},
    {0, NULL, NULL},
  };

  if (!deinterlace_field_layout_type) {
    deinterlace_field_layout_type =
        g_enum_register_static ("GstDeinterlaceFieldLayout",
        field_layout_types);
  }
  return deinterlace_field_layout_type;
}

#define GST_TYPE_DEINTERLACE_MODES (gst_deinterlace_modes_get_type ())
static GType
gst_deinterlace_modes_get_type (void)
{
  static GType deinterlace_modes_type = 0;

  static const GEnumValue modes_types[] = {
    {GST_DEINTERLACE_MODE_AUTO, "Auto detection", "auto"},
    {GST_DEINTERLACE_MODE_INTERLACED, "Force deinterlacing", "interlaced"},
    {GST_DEINTERLACE_MODE_DISABLED, "Run in passthrough mode", "disabled"},
    {0, NULL, NULL},
  };

  if (!deinterlace_modes_type) {
    deinterlace_modes_type =
        g_enum_register_static ("GstDeinterlaceModes", modes_types);
  }
  return deinterlace_modes_type;
}

#define GST_TYPE_DEINTERLACE_LOCKING (gst_deinterlace_locking_get_type ())
static GType
gst_deinterlace_locking_get_type (void)
{
  static GType deinterlace_locking_type = 0;

  if (!deinterlace_locking_type) {
    deinterlace_locking_type =
        g_enum_register_static ("GstDeinterlaceLocking", locking_types);
  }

  return deinterlace_locking_type;
}


#define DEINTERLACE_CAPS \
    GST_VIDEO_CAPS_YUV ("{ AYUV, Y444, YUY2, YVYU, UYVY, Y42B, I420, YV12, Y41B, NV12, NV21 }") ";" \
    GST_VIDEO_CAPS_ARGB ";" GST_VIDEO_CAPS_ABGR ";" \
    GST_VIDEO_CAPS_RGBA ";" GST_VIDEO_CAPS_BGRA ";" \
    GST_VIDEO_CAPS_xRGB ";" GST_VIDEO_CAPS_xBGR ";" \
    GST_VIDEO_CAPS_RGBx ";" GST_VIDEO_CAPS_BGRx ";" \
    GST_VIDEO_CAPS_RGB ";" GST_VIDEO_CAPS_BGR

static GstStaticPadTemplate src_templ = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (DEINTERLACE_CAPS)
    );

static GstStaticPadTemplate sink_templ = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (DEINTERLACE_CAPS)
    );

static void gst_deinterlace_finalize (GObject * self);
static void gst_deinterlace_set_property (GObject * self, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_deinterlace_get_property (GObject * self, guint prop_id,
    GValue * value, GParamSpec * pspec);

static GstCaps *gst_deinterlace_getcaps (GstPad * pad);
static gboolean gst_deinterlace_setcaps (GstPad * pad, GstCaps * caps);
static gboolean gst_deinterlace_sink_event (GstPad * pad, GstEvent * event);
static gboolean gst_deinterlace_sink_query (GstPad * pad, GstQuery * query);
static GstFlowReturn gst_deinterlace_chain (GstPad * pad, GstBuffer * buffer);
static GstFlowReturn gst_deinterlace_alloc_buffer (GstPad * pad, guint64 offset,
    guint size, GstCaps * caps, GstBuffer ** buf);
static GstStateChangeReturn gst_deinterlace_change_state (GstElement * element,
    GstStateChange transition);

static gboolean gst_deinterlace_src_event (GstPad * pad, GstEvent * event);
static gboolean gst_deinterlace_src_query (GstPad * pad, GstQuery * query);
static const GstQueryType *gst_deinterlace_src_query_types (GstPad * pad);

static GstFlowReturn gst_deinterlace_output_frame (GstDeinterlace * self,
    gboolean flushing);
static void gst_deinterlace_reset (GstDeinterlace * self);
static void gst_deinterlace_update_qos (GstDeinterlace * self,
    gdouble proportion, GstClockTimeDiff diff, GstClockTime time);
static void gst_deinterlace_reset_qos (GstDeinterlace * self);
static void gst_deinterlace_read_qos (GstDeinterlace * self,
    gdouble * proportion, GstClockTime * time);

static void gst_deinterlace_child_proxy_interface_init (gpointer g_iface,
    gpointer iface_data);

static void
_do_init (GType object_type)
{
  const GInterfaceInfo child_proxy_interface_info = {
    (GInterfaceInitFunc) gst_deinterlace_child_proxy_interface_init,
    NULL,                       /* interface_finalize */
    NULL                        /* interface_data */
  };

  g_type_add_interface_static (object_type, GST_TYPE_CHILD_PROXY,
      &child_proxy_interface_info);
}

GST_BOILERPLATE_FULL (GstDeinterlace, gst_deinterlace, GstElement,
    GST_TYPE_ELEMENT, _do_init);

static const struct
{
  GType (*get_type) (void);
} _method_types[] = {
  {
  gst_deinterlace_method_tomsmocomp_get_type}, {
  gst_deinterlace_method_greedy_h_get_type}, {
  gst_deinterlace_method_greedy_l_get_type}, {
  gst_deinterlace_method_vfir_get_type}, {
  gst_deinterlace_method_linear_get_type}, {
  gst_deinterlace_method_linear_blend_get_type}, {
  gst_deinterlace_method_scaler_bob_get_type}, {
  gst_deinterlace_method_weave_get_type}, {
  gst_deinterlace_method_weave_tff_get_type}, {
  gst_deinterlace_method_weave_bff_get_type}
};

static void
gst_deinterlace_set_method (GstDeinterlace * self, GstDeinterlaceMethods method)
{
  GType method_type;

  GST_DEBUG_OBJECT (self, "Setting new method %d", method);

  if (self->method) {
    if (self->method_id == method &&
        gst_deinterlace_method_supported (G_TYPE_FROM_INSTANCE (self->method),
            self->format, self->width, self->height)) {
      GST_DEBUG_OBJECT (self, "Reusing current method");
      return;
    }

    gst_child_proxy_child_removed (GST_OBJECT (self),
        GST_OBJECT (self->method));
    gst_object_unparent (GST_OBJECT (self->method));
    self->method = NULL;
  }

  method_type =
      _method_types[method].get_type !=
      NULL ? _method_types[method].get_type () : G_TYPE_INVALID;
  if (method_type == G_TYPE_INVALID
      || !gst_deinterlace_method_supported (method_type, self->format,
          self->width, self->height)) {
    GType tmp;
    gint i;

    method_type = G_TYPE_INVALID;

    GST_WARNING_OBJECT (self, "Method doesn't support requested format");
    for (i = 0; i < G_N_ELEMENTS (_method_types); i++) {
      if (_method_types[i].get_type == NULL)
        continue;
      tmp = _method_types[i].get_type ();
      if (gst_deinterlace_method_supported (tmp, self->format, self->width,
              self->height)) {
        GST_DEBUG_OBJECT (self, "Using method %d", i);
        method_type = tmp;
        method = i;
        break;
      }
    }
    /* If we get here we must have invalid caps! */
    g_assert (method_type != G_TYPE_INVALID);
  }

  self->method = g_object_new (method_type, NULL);
  self->method_id = method;

  gst_object_set_name (GST_OBJECT (self->method), "method");
  gst_object_set_parent (GST_OBJECT (self->method), GST_OBJECT (self));
  gst_child_proxy_child_added (GST_OBJECT (self), GST_OBJECT (self->method));

  if (self->method)
    gst_deinterlace_method_setup (self->method, self->format, self->width,
        self->height);
}

static gboolean
gst_deinterlace_clip_buffer (GstDeinterlace * self, GstBuffer * buffer)
{
  gboolean ret = TRUE;
  GstClockTime start, stop;
  gint64 cstart, cstop;

  GST_DEBUG_OBJECT (self,
      "Clipping buffer to the current segment: %" GST_TIME_FORMAT " -- %"
      GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)),
      GST_TIME_ARGS (GST_BUFFER_DURATION (buffer)));
  GST_DEBUG_OBJECT (self, "Current segment: %" GST_SEGMENT_FORMAT,
      &self->segment);

  if (G_UNLIKELY (self->segment.format != GST_FORMAT_TIME))
    goto beach;
  if (G_UNLIKELY (!GST_BUFFER_TIMESTAMP_IS_VALID (buffer)))
    goto beach;

  start = GST_BUFFER_TIMESTAMP (buffer);
  stop = start + GST_BUFFER_DURATION (buffer);

  if (!(ret = gst_segment_clip (&self->segment, GST_FORMAT_TIME,
              start, stop, &cstart, &cstop)))
    goto beach;

  GST_BUFFER_TIMESTAMP (buffer) = cstart;
  if (GST_CLOCK_TIME_IS_VALID (cstop))
    GST_BUFFER_DURATION (buffer) = cstop - cstart;

beach:
  if (ret)
    GST_DEBUG_OBJECT (self,
        "Clipped buffer to the current segment: %" GST_TIME_FORMAT " -- %"
        GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)),
        GST_TIME_ARGS (GST_BUFFER_DURATION (buffer)));
  else
    GST_DEBUG_OBJECT (self, "Buffer outside the current segment -- dropping");

  return ret;
}

static void
gst_deinterlace_base_init (gpointer klass)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&src_templ));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&sink_templ));

  gst_element_class_set_details_simple (element_class,
      "Deinterlacer",
      "Filter/Effect/Video/Deinterlace",
      "Deinterlace Methods ported from DScaler/TvTime",
      "Martin Eikermann <meiker@upb.de>, "
      "Sebastian Dröge <sebastian.droege@collabora.co.uk>");
}

static void
gst_deinterlace_class_init (GstDeinterlaceClass * klass)
{
  GObjectClass *gobject_class = (GObjectClass *) klass;

  GstElementClass *element_class = (GstElementClass *) klass;

  gobject_class->set_property = gst_deinterlace_set_property;
  gobject_class->get_property = gst_deinterlace_get_property;
  gobject_class->finalize = gst_deinterlace_finalize;

  /**
   * GstDeinterlace:mode
   * 
   * This selects whether the deinterlacing methods 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 (gobject_class, PROP_MODE,
      g_param_spec_enum ("mode",
          "Mode",
          "Deinterlace Mode",
          GST_TYPE_DEINTERLACE_MODES,
          DEFAULT_MODE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)
      );

  /**
   * GstDeinterlace:method
   * 
   * Selects the different deinterlacing algorithms that can be used.
   * These provide different quality and CPU usage.
   *
   * Some methods provide parameters which can be set by getting
   * the "method" child via the #GstChildProxy interface and
   * setting the appropiate properties on it.
   *
   * <itemizedlist>
   * <listitem>
   * <para>
   * tomsmocomp
   * Motion Adaptive: Motion Search
   * </para>
   * </listitem>
   * <listitem>
   * <para>
   * greedyh
   * Motion Adaptive: Advanced Detection
   * </para>
   * </listitem>
   * <listitem>
   * <para>
   * greedyl
   * Motion Adaptive: Simple Detection
   * </para>
   * </listitem>
   * <listitem>
   * <para>
   * vfir
   * Blur vertical
   * </para>
   * </listitem>
   * <listitem>
   * <para>
   * linear
   * Linear interpolation
   * </para>
   * </listitem>
   * <listitem>
   * <para>
   * linearblend
   * Linear interpolation in time domain.  Any motion causes significant
   * ghosting, so this method should not be used.
   * </para>
   * </listitem>
   * <listitem>
   * <para>
   * scalerbob
   * Double lines
   * </para>
   * </listitem>
   * <listitem>
   * <para>
   * weave
   * Weave.  Bad quality, do not use.
   * </para>
   * </listitem>
   * <listitem>
   * <para>
   * weavetff
   * Progressive: Top Field First.  Bad quality, do not use.
   * </para>
   * </listitem>
   * <listitem>
   * <para>
   * weavebff
   * Progressive: Bottom Field First.  Bad quality, do not use.
   * </para>
   * </listitem>
   * </itemizedlist>
   */
  g_object_class_install_property (gobject_class, PROP_METHOD,
      g_param_spec_enum ("method",
          "Method",
          "Deinterlace Method",
          GST_TYPE_DEINTERLACE_METHODS,
          DEFAULT_METHOD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)
      );

  /**
   * GstDeinterlace:fields
   *
   * This selects which fields should be output. If "all" is selected
   * the output framerate will be double.
   *
   */
  g_object_class_install_property (gobject_class, PROP_FIELDS,
      g_param_spec_enum ("fields",
          "fields",
          "Fields to use for deinterlacing",
          GST_TYPE_DEINTERLACE_FIELDS,
          DEFAULT_FIELDS, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)
      );

  /**
   * GstDeinterlace:layout
   *
   * This selects which fields is the first in time.
   *
   */
  g_object_class_install_property (gobject_class, PROP_FIELD_LAYOUT,
      g_param_spec_enum ("tff",
          "tff",
          "Deinterlace top field first",
          GST_TYPE_DEINTERLACE_FIELD_LAYOUT,
          DEFAULT_FIELD_LAYOUT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)
      );

  /**
   * GstDeinterlace:locking
   *
   * This selects which approach to pattern locking is used which affects
   * processing latency and accuracy of timestamp adjustment for telecine
   * streams.
   *
   * Since: 0.10.31
   *
   */
  g_object_class_install_property (gobject_class, PROP_LOCKING,
      g_param_spec_enum ("locking", "locking", "Pattern locking mode",
          GST_TYPE_DEINTERLACE_LOCKING, DEFAULT_LOCKING,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  /**
   * GstDeinterlace:ignore-obscure
   *
   * This selects whether to ignore obscure/rare telecine patterns.
   * NTSC 2:3 pulldown variants are the only really common patterns.
   *
   * Since: 0.10.31
   *
   */
  g_object_class_install_property (gobject_class, PROP_IGNORE_OBSCURE,
      g_param_spec_boolean ("ignore-obscure", "ignore-obscure",
          "Ignore obscure telecine patterns (only consider P, I and 2:3 "
          "variants).", DEFAULT_IGNORE_OBSCURE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  /**
   * GstDeinterlace:drop-orphans
   *
   * This selects whether to drop orphan fields at the beginning of telecine
   * patterns in active locking mode.
   *
   * Since: 0.10.31
   *
   */
  g_object_class_install_property (gobject_class, PROP_DROP_ORPHANS,
      g_param_spec_boolean ("drop-orphans", "drop-orphans",
          "Drop orphan fields at the beginning of telecine patterns in "
          "active locking mode.", DEFAULT_DROP_ORPHANS,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  element_class->change_state =
      GST_DEBUG_FUNCPTR (gst_deinterlace_change_state);
}

static GstObject *
gst_deinterlace_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
    guint index)
{
  GstDeinterlace *self = GST_DEINTERLACE (child_proxy);

  g_return_val_if_fail (index == 0, NULL);

  return gst_object_ref (self->method);
}

static guint
gst_deinterlace_child_proxy_get_children_count (GstChildProxy * child_proxy)
{
  GstDeinterlace *self = GST_DEINTERLACE (child_proxy);

  return ((self->method) ? 1 : 0);
}

static void
gst_deinterlace_child_proxy_interface_init (gpointer g_iface,
    gpointer iface_data)
{
  GstChildProxyInterface *iface = g_iface;

  iface->get_child_by_index = gst_deinterlace_child_proxy_get_child_by_index;
  iface->get_children_count = gst_deinterlace_child_proxy_get_children_count;
}

static void
gst_deinterlace_init (GstDeinterlace * self, GstDeinterlaceClass * klass)
{
  self->sinkpad = gst_pad_new_from_static_template (&sink_templ, "sink");
  gst_pad_set_chain_function (self->sinkpad,
      GST_DEBUG_FUNCPTR (gst_deinterlace_chain));
  gst_pad_set_event_function (self->sinkpad,
      GST_DEBUG_FUNCPTR (gst_deinterlace_sink_event));
  gst_pad_set_setcaps_function (self->sinkpad,
      GST_DEBUG_FUNCPTR (gst_deinterlace_setcaps));
  gst_pad_set_getcaps_function (self->sinkpad,
      GST_DEBUG_FUNCPTR (gst_deinterlace_getcaps));
  gst_pad_set_query_function (self->sinkpad,
      GST_DEBUG_FUNCPTR (gst_deinterlace_sink_query));
  gst_pad_set_bufferalloc_function (self->sinkpad,
      GST_DEBUG_FUNCPTR (gst_deinterlace_alloc_buffer));
  gst_element_add_pad (GST_ELEMENT (self), self->sinkpad);

  self->srcpad = gst_pad_new_from_static_template (&src_templ, "src");
  gst_pad_set_event_function (self->srcpad,
      GST_DEBUG_FUNCPTR (gst_deinterlace_src_event));
  gst_pad_set_query_type_function (self->srcpad,
      GST_DEBUG_FUNCPTR (gst_deinterlace_src_query_types));
  gst_pad_set_query_function (self->srcpad,
      GST_DEBUG_FUNCPTR (gst_deinterlace_src_query));
  gst_pad_set_getcaps_function (self->srcpad,
      GST_DEBUG_FUNCPTR (gst_deinterlace_getcaps));
  gst_element_add_pad (GST_ELEMENT (self), self->srcpad);

  self->mode = DEFAULT_MODE;
  self->user_set_method_id = DEFAULT_METHOD;
  gst_deinterlace_set_method (self, self->user_set_method_id);
  self->fields = DEFAULT_FIELDS;
  self->field_layout = DEFAULT_FIELD_LAYOUT;
  self->locking = DEFAULT_LOCKING;
  self->ignore_obscure = DEFAULT_IGNORE_OBSCURE;
  self->drop_orphans = DEFAULT_DROP_ORPHANS;

  self->low_latency = -1;
  self->pattern = -1;
  self->pattern_phase = -1;
  self->pattern_count = 0;
  self->output_count = 0;
  self->pattern_base_ts = GST_CLOCK_TIME_NONE;
  self->pattern_buf_dur = GST_CLOCK_TIME_NONE;
  self->still_frame_mode = FALSE;

  gst_deinterlace_reset (self);
}

static void
gst_deinterlace_reset_history (GstDeinterlace * self, gboolean drop_all)
{
  gint i;

  if (!drop_all) {
    GST_DEBUG_OBJECT (self, "Flushing history (count %d)", self->history_count);
    while (self->history_count > 0) {
      if (gst_deinterlace_output_frame (self, TRUE) != GST_FLOW_OK) {
        /* Encountered error, or flushing -> skip and drop all remaining */
        drop_all = TRUE;
        break;
      }
    }
  }
  if (drop_all) {
    GST_DEBUG_OBJECT (self, "Resetting history (count %d)",
        self->history_count);

    for (i = 0; i < self->history_count; i++) {
      if (self->field_history[i].buf) {
        gst_buffer_unref (self->field_history[i].buf);
        self->field_history[i].buf = NULL;
      }
    }
  }
  memset (self->field_history, 0,
      GST_DEINTERLACE_MAX_FIELD_HISTORY * sizeof (GstDeinterlaceField));
  self->history_count = 0;
  memset (self->buf_states, 0,
      GST_DEINTERLACE_MAX_BUFFER_STATE_HISTORY *
      sizeof (GstDeinterlaceBufferState));
  self->state_count = 0;
  self->pattern_lock = FALSE;
  self->pattern_refresh = TRUE;

  if (!self->still_frame_mode && self->last_buffer) {
    gst_buffer_unref (self->last_buffer);
    self->last_buffer = NULL;
  }
}

static void
gst_deinterlace_update_passthrough (GstDeinterlace * self)
{
  self->passthrough = (self->mode == GST_DEINTERLACE_MODE_DISABLED
      || (!self->interlaced && self->mode != GST_DEINTERLACE_MODE_INTERLACED));
  GST_DEBUG_OBJECT (self, "Passthrough: %d", self->passthrough);
}

static void
gst_deinterlace_reset (GstDeinterlace * self)
{
  GST_DEBUG_OBJECT (self, "Resetting internal state");

  self->format = GST_VIDEO_FORMAT_UNKNOWN;
  self->width = 0;
  self->height = 0;
  self->frame_size = 0;
  self->fps_n = self->fps_d = 0;
  self->passthrough = FALSE;

  self->reconfigure = FALSE;
  if (self->new_mode != -1)
    self->mode = self->new_mode;
  if (self->new_fields != -1)
    self->fields = self->new_fields;
  self->new_mode = -1;
  self->new_fields = -1;

  gst_segment_init (&self->segment, GST_FORMAT_UNDEFINED);

  if (self->request_caps)
    gst_caps_unref (self->request_caps);
  self->request_caps = NULL;

  gst_deinterlace_reset_history (self, TRUE);

  gst_deinterlace_reset_qos (self);

  self->need_more = FALSE;
  self->have_eos = FALSE;
}

static void
gst_deinterlace_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstDeinterlace *self;

  g_return_if_fail (GST_IS_DEINTERLACE (object));
  self = GST_DEINTERLACE (object);

  switch (prop_id) {
    case PROP_MODE:{
      gint new_mode;

      GST_OBJECT_LOCK (self);
      new_mode = g_value_get_enum (value);
      if (self->mode != new_mode && GST_PAD_CAPS (self->srcpad)) {
        self->reconfigure = TRUE;
        self->new_mode = new_mode;
      } else {
        self->mode = new_mode;
        gst_deinterlace_update_passthrough (self);
      }
      GST_OBJECT_UNLOCK (self);
      break;
    }
    case PROP_METHOD:
      self->user_set_method_id = g_value_get_enum (value);
      gst_deinterlace_set_method (self, self->user_set_method_id);
      break;
    case PROP_FIELDS:{
      gint new_fields;

      GST_OBJECT_LOCK (self);
      new_fields = g_value_get_enum (value);
      if (self->fields != new_fields && GST_PAD_CAPS (self->srcpad)) {
        self->reconfigure = TRUE;
        self->new_fields = new_fields;
      } else {
        self->fields = new_fields;
      }
      GST_OBJECT_UNLOCK (self);
      break;
    }
    case PROP_FIELD_LAYOUT:
      self->field_layout = g_value_get_enum (value);
      break;
    case PROP_LOCKING:
      self->locking = g_value_get_enum (value);
      break;
    case PROP_IGNORE_OBSCURE:
      self->ignore_obscure = g_value_get_boolean (value);
      break;
    case PROP_DROP_ORPHANS:
      self->drop_orphans = g_value_get_boolean (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (self, prop_id, pspec);
  }

}

static void
gst_deinterlace_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstDeinterlace *self;

  g_return_if_fail (GST_IS_DEINTERLACE (object));
  self = GST_DEINTERLACE (object);

  switch (prop_id) {
    case PROP_MODE:
      g_value_set_enum (value, self->mode);
      break;
    case PROP_METHOD:
      g_value_set_enum (value, self->user_set_method_id);
      break;
    case PROP_FIELDS:
      g_value_set_enum (value, self->fields);
      break;
    case PROP_FIELD_LAYOUT:
      g_value_set_enum (value, self->field_layout);
      break;
    case PROP_LOCKING:
      g_value_set_enum (value, self->locking);
      break;
    case PROP_IGNORE_OBSCURE:
      g_value_set_boolean (value, self->ignore_obscure);
      break;
    case PROP_DROP_ORPHANS:
      g_value_set_boolean (value, self->drop_orphans);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (self, prop_id, pspec);
  }
}

static void
gst_deinterlace_finalize (GObject * object)
{
  GstDeinterlace *self = GST_DEINTERLACE (object);

  gst_deinterlace_reset (self);

  if (self->method) {
    gst_object_unparent (GST_OBJECT (self->method));
    self->method = NULL;
  }

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

static void
gst_deinterlace_update_pattern_timestamps (GstDeinterlace * self)
{
  gint state_idx;
  if (self->low_latency) {
    /* in low-latency mode the buffer state history contains old buffer
     * states as well as the current one and perhaps some future ones.
     * the current buffer's state is given by the number of field pairs
     * rounded up, minus 1. the below is equivalent */
    state_idx = (self->history_count - 1) >> 1;
  } else {
    /* in high-latency mode state_count - 1 is the current buffer's state */
    state_idx = self->state_count - 1;
  }

  self->pattern_base_ts = self->buf_states[state_idx].timestamp;
  self->pattern_buf_dur =
      (self->buf_states[state_idx].duration *
      telecine_patterns[self->pattern].ratio_d) /
      telecine_patterns[self->pattern].ratio_n;
  GST_DEBUG_OBJECT (self,
      "Starting a new pattern repeat with base ts %" GST_TIME_FORMAT
      " and dur %" GST_TIME_FORMAT, GST_TIME_ARGS (self->pattern_base_ts),
      GST_TIME_ARGS (self->pattern_buf_dur));
}

static GstBuffer *
gst_deinterlace_pop_history (GstDeinterlace * self)
{
  GstBuffer *buffer;

  g_return_val_if_fail (self->history_count > 0, NULL);

  GST_DEBUG_OBJECT (self, "Pop last history buffer -- current history size %d",
      self->history_count);

  buffer = self->field_history[self->history_count - 1].buf;

  self->history_count--;
  if (self->locking != GST_DEINTERLACE_LOCKING_NONE && (!self->history_count
          || GST_BUFFER_DATA (buffer) !=
          GST_BUFFER_DATA (self->field_history[self->history_count - 1].buf))) {
    if (!self->low_latency)
      self->state_count--;
    if (self->pattern_lock) {
      self->pattern_count++;
      if (self->pattern != -1
          && self->pattern_count >= telecine_patterns[self->pattern].length) {
        self->pattern_count = 0;
        self->output_count = 0;
        gst_deinterlace_update_pattern_timestamps (self);
      }
    }
  }

  GST_DEBUG_OBJECT (self, "Returning buffer: %p %" GST_TIME_FORMAT
      " with duration %" GST_TIME_FORMAT " and size %u", buffer,
      GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)),
      GST_TIME_ARGS (GST_BUFFER_DURATION (buffer)), GST_BUFFER_SIZE (buffer));

  return buffer;
}

typedef enum
{
  GST_DEINTERLACE_PROGRESSIVE,
  GST_DEINTERLACE_INTERLACED,
  GST_DEINTERLACE_TELECINE,
} GstDeinterlaceInterlacingMethod;

static GstDeinterlaceInterlacingMethod
gst_deinterlace_get_interlacing_method (const GstCaps * caps)
{
  GstDeinterlaceInterlacingMethod method = 0;
  gboolean interlaced;

  /* check interlaced cap */
  gst_structure_get_boolean (gst_caps_get_structure (caps, 0), "interlaced",
      &interlaced);

  method =
      interlaced ? GST_DEINTERLACE_INTERLACED : GST_DEINTERLACE_PROGRESSIVE;

  if (method == GST_DEINTERLACE_INTERLACED) {
    const gchar *temp =
        gst_structure_get_string (gst_caps_get_structure (caps, 0),
        "interlacing-method");
    if (temp && g_str_equal (temp, "telecine"))
      method = GST_DEINTERLACE_TELECINE;
  }

  return method;
}

static void
gst_deinterlace_get_buffer_state (GstDeinterlace * self, GstBuffer * buffer,
    guint8 * state, GstDeinterlaceInterlacingMethod * i_method)
{
  GstDeinterlaceInterlacingMethod interlacing_method;

  if (!(i_method || state))
    return;

  interlacing_method =
      gst_deinterlace_get_interlacing_method (GST_BUFFER_CAPS (buffer));

  if (state) {
    if (interlacing_method == GST_DEINTERLACE_TELECINE) {
      if (GST_BUFFER_FLAG_IS_SET (buffer, GST_VIDEO_BUFFER_RFF)) {
        *state = GST_DEINTERLACE_BUFFER_STATE_DROP;
      } else if (GST_BUFFER_FLAG_IS_SET (buffer, GST_VIDEO_BUFFER_ONEFIELD)) {
        /* tc top if tff, tc bottom otherwise */
        if (GST_BUFFER_FLAG_IS_SET (buffer, GST_VIDEO_BUFFER_TFF)) {
          *state = GST_DEINTERLACE_BUFFER_STATE_TC_T;
        } else {
          *state = GST_DEINTERLACE_BUFFER_STATE_TC_B;
        }
      } else if (GST_BUFFER_FLAG_IS_SET (buffer, GST_VIDEO_BUFFER_PROGRESSIVE)) {
        *state = GST_DEINTERLACE_BUFFER_STATE_TC_P;
      } else {
        *state = GST_DEINTERLACE_BUFFER_STATE_TC_M;
      }
    } else {
      if (interlacing_method == GST_DEINTERLACE_INTERLACED) {
        *state = GST_DEINTERLACE_BUFFER_STATE_I;
      } else {
        *state = GST_DEINTERLACE_BUFFER_STATE_P;
      }
    }
  }

  if (i_method)
    *i_method = interlacing_method;
}

static void
gst_deinterlace_push_history (GstDeinterlace * self, GstBuffer * buffer)
{
  int i = 1;
  GstClockTime timestamp;
  GstDeinterlaceFieldLayout field_layout = self->field_layout;
  gboolean repeated = GST_BUFFER_FLAG_IS_SET (buffer, GST_VIDEO_BUFFER_RFF);
  gboolean tff = GST_BUFFER_FLAG_IS_SET (buffer, GST_VIDEO_BUFFER_TFF);
  gboolean onefield =
      GST_BUFFER_FLAG_IS_SET (buffer, GST_VIDEO_BUFFER_ONEFIELD);
  GstBuffer *field1, *field2;
  guint fields_to_push = (onefield) ? 1 : (!repeated) ? 2 : 3;
  gint field1_flags, field2_flags;
  GstDeinterlaceInterlacingMethod interlacing_method;
  guint8 buf_state;

  g_return_if_fail (self->history_count <
      GST_DEINTERLACE_MAX_FIELD_HISTORY - fields_to_push);

  gst_deinterlace_get_buffer_state (self, buffer, &buf_state,
      &interlacing_method);

  GST_DEBUG_OBJECT (self,
      "Pushing new buffer to the history: ptr %p at %" GST_TIME_FORMAT
      " with duration %" GST_TIME_FORMAT
      ", size %u, state %u, interlacing method %s", GST_BUFFER_DATA (buffer),
      GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)),
      GST_TIME_ARGS (GST_BUFFER_DURATION (buffer)), GST_BUFFER_SIZE (buffer),
      buf_state,
      interlacing_method ==
      GST_DEINTERLACE_TELECINE ? "TC" : interlacing_method ==
      GST_DEINTERLACE_INTERLACED ? "I" : "P");

  /* move up for new state */
  memmove (&self->buf_states[1], &self->buf_states[0],
      (GST_DEINTERLACE_MAX_BUFFER_STATE_HISTORY - 1) *
      sizeof (GstDeinterlaceBufferState));
  self->buf_states[0].state = buf_state;
  self->buf_states[0].timestamp = GST_BUFFER_TIMESTAMP (buffer);
  self->buf_states[0].duration = GST_BUFFER_DURATION (buffer);
  if (self->state_count < GST_DEINTERLACE_MAX_BUFFER_STATE_HISTORY)
    self->state_count++;

  if (buf_state == GST_DEINTERLACE_BUFFER_STATE_DROP) {
    GST_DEBUG_OBJECT (self,
        "Buffer contains only unneeded repeated fields, dropping and not"
        "adding to field history");
    gst_buffer_unref (buffer);
    return;
  }

  /* telecine does not make use of repeated fields */
  if (interlacing_method == GST_DEINTERLACE_TELECINE)
    repeated = FALSE;

  for (i = GST_DEINTERLACE_MAX_FIELD_HISTORY - 1; i >= fields_to_push; i--) {
    self->field_history[i].buf = self->field_history[i - fields_to_push].buf;
    self->field_history[i].flags =
        self->field_history[i - fields_to_push].flags;
  }

  if (field_layout == GST_DEINTERLACE_LAYOUT_AUTO) {
    if (!self->interlaced) {
      GST_WARNING_OBJECT (self, "Can't detect field layout -- assuming TFF");
      field_layout = GST_DEINTERLACE_LAYOUT_TFF;
    } else if (tff) {
      field_layout = GST_DEINTERLACE_LAYOUT_TFF;
    } else {
      field_layout = GST_DEINTERLACE_LAYOUT_BFF;
    }
  }

  if (field_layout == GST_DEINTERLACE_LAYOUT_TFF) {
    GST_DEBUG_OBJECT (self, "Top field first");
    field1 = gst_buffer_make_metadata_writable (gst_buffer_ref (buffer));
    field1_flags = PICTURE_INTERLACED_TOP;
    field2 = gst_buffer_make_metadata_writable (gst_buffer_ref (buffer));
    field2_flags = PICTURE_INTERLACED_BOTTOM;
  } else {
    GST_DEBUG_OBJECT (self, "Bottom field first");
    field1 = gst_buffer_make_metadata_writable (gst_buffer_ref (buffer));
    field1_flags = PICTURE_INTERLACED_BOTTOM;
    field2 = gst_buffer_make_metadata_writable (gst_buffer_ref (buffer));
    field2_flags = PICTURE_INTERLACED_TOP;
  }

  if (interlacing_method != GST_DEINTERLACE_TELECINE) {
    /* Timestamps are assigned to the field buffers under the assumption that
       the timestamp of the buffer equals the first fields timestamp */

    timestamp = GST_BUFFER_TIMESTAMP (buffer);
    GST_BUFFER_TIMESTAMP (field1) = timestamp;
    GST_BUFFER_TIMESTAMP (field2) = timestamp + self->field_duration;
    if (repeated)
      GST_BUFFER_TIMESTAMP (field2) += self->field_duration;
  }

  if (repeated) {
    self->field_history[2].buf = field1;
    self->field_history[2].flags = field1_flags;

    self->field_history[1].buf = field2;
    self->field_history[1].flags = field2_flags;

    self->field_history[0].buf =
        gst_buffer_make_metadata_writable (gst_buffer_ref (field1));
    GST_BUFFER_TIMESTAMP (self->field_history[0].buf) +=
        2 * self->field_duration;
    self->field_history[0].flags = field1_flags;
  } else if (!onefield) {
    self->field_history[1].buf = field1;
    self->field_history[1].flags = field1_flags;

    self->field_history[0].buf = field2;
    self->field_history[0].flags = field2_flags;
  } else {                      /* onefield */
    self->field_history[0].buf = field1;
    self->field_history[0].flags = field1_flags;
    gst_buffer_unref (field2);
  }

  self->history_count += fields_to_push;

  GST_DEBUG_OBJECT (self, "Pushed buffer -- current history size %d",
      self->history_count);

  if (self->last_buffer)
    gst_buffer_unref (self->last_buffer);
  self->last_buffer = buffer;
}

static void
gst_deinterlace_update_qos (GstDeinterlace * self, gdouble proportion,
    GstClockTimeDiff diff, GstClockTime timestamp)
{
  GST_DEBUG_OBJECT (self,
      "Updating QoS: proportion %lf, diff %s%" GST_TIME_FORMAT ", timestamp %"
      GST_TIME_FORMAT, proportion, (diff < 0) ? "-" : "",
      GST_TIME_ARGS (ABS (diff)), GST_TIME_ARGS (timestamp));

  GST_OBJECT_LOCK (self);
  self->proportion = proportion;
  if (G_LIKELY (timestamp != GST_CLOCK_TIME_NONE)) {
    if (G_UNLIKELY (diff > 0))
      self->earliest_time =
          timestamp + 2 * diff + ((self->fields ==
              GST_DEINTERLACE_ALL) ? self->field_duration : 2 *
          self->field_duration);
    else
      self->earliest_time = timestamp + diff;
  } else {
    self->earliest_time = GST_CLOCK_TIME_NONE;
  }
  GST_OBJECT_UNLOCK (self);
}

static void
gst_deinterlace_reset_qos (GstDeinterlace * self)
{
  gst_deinterlace_update_qos (self, 0.5, 0, GST_CLOCK_TIME_NONE);
}

static void
gst_deinterlace_read_qos (GstDeinterlace * self, gdouble * proportion,
    GstClockTime * time)
{
  GST_OBJECT_LOCK (self);
  *proportion = self->proportion;
  *time = self->earliest_time;
  GST_OBJECT_UNLOCK (self);
}

/* Perform qos calculations before processing the next frame. Returns TRUE if
 * the frame should be processed, FALSE if the frame can be dropped entirely */
static gboolean
gst_deinterlace_do_qos (GstDeinterlace * self, GstClockTime timestamp)
{
  GstClockTime qostime, earliest_time;
  gdouble proportion;

  /* no timestamp, can't do QoS => process frame */
  if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (timestamp))) {
    GST_LOG_OBJECT (self, "invalid timestamp, can't do QoS, process frame");
    return TRUE;
  }

  /* get latest QoS observation values */
  gst_deinterlace_read_qos (self, &proportion, &earliest_time);

  /* skip qos if we have no observation (yet) => process frame */
  if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (earliest_time))) {
    GST_LOG_OBJECT (self, "no observation yet, process frame");
    return TRUE;
  }

  /* qos is done on running time */
  qostime = gst_segment_to_running_time (&self->segment, GST_FORMAT_TIME,
      timestamp);

  /* see how our next timestamp relates to the latest qos timestamp */
  GST_LOG_OBJECT (self, "qostime %" GST_TIME_FORMAT ", earliest %"
      GST_TIME_FORMAT, GST_TIME_ARGS (qostime), GST_TIME_ARGS (earliest_time));

  if (qostime != GST_CLOCK_TIME_NONE && qostime <= earliest_time) {
    GST_DEBUG_OBJECT (self, "we are late, drop frame");
    return FALSE;
  }

  GST_LOG_OBJECT (self, "process frame");
  return TRUE;
}

static gboolean
gst_deinterlace_fix_timestamps (GstDeinterlace * self,
    GstDeinterlaceField * field1, GstDeinterlaceField * field2)
{
  GstDeinterlaceField *field3, *field4;
  GstDeinterlaceInterlacingMethod interlacing_method;

  if (self->pattern_lock && self->pattern > -1) {
    /* accurate pattern-locked timestamp adjustment */
    if (!self->pattern_count)
      gst_deinterlace_update_pattern_timestamps (self);

    GST_BUFFER_TIMESTAMP (field1->buf) =
        self->pattern_base_ts + self->output_count * self->pattern_buf_dur;
    GST_BUFFER_DURATION (field1->buf) = self->pattern_buf_dur;
    self->output_count++;
  } else {
    /* naive (but low-latency) timestamp adjustment based on subsequent
     * fields/buffers */
    if (field2
        && GST_BUFFER_DATA (field1->buf) != GST_BUFFER_DATA (field2->buf)) {
      if (GST_BUFFER_TIMESTAMP (field1->buf) +
          GST_BUFFER_DURATION (field1->buf) ==
          GST_BUFFER_TIMESTAMP (field2->buf)) {
        GST_BUFFER_TIMESTAMP (field1->buf) =
            GST_BUFFER_TIMESTAMP (field2->buf) =
            (GST_BUFFER_TIMESTAMP (field1->buf) +
            GST_BUFFER_TIMESTAMP (field2->buf)) / 2;
      } else {
        GST_BUFFER_TIMESTAMP (field2->buf) = GST_BUFFER_TIMESTAMP (field1->buf);
      }
    }

    if (self->history_count < 3) {
      GST_DEBUG_OBJECT (self, "Need more fields (have %d, need 3)",
          self->history_count);
      return FALSE;
    }

    field3 = &self->field_history[self->history_count - 3];
    interlacing_method =
        gst_deinterlace_get_interlacing_method (GST_BUFFER_CAPS (field3->buf));
    if (interlacing_method == GST_DEINTERLACE_TELECINE) {
      if (self->history_count < 4) {
        GST_DEBUG_OBJECT (self, "Need more fields (have %d, need 4)",
            self->history_count);
        return FALSE;
      }

      field4 = &self->field_history[self->history_count - 4];
      if (GST_BUFFER_DATA (field3->buf) != GST_BUFFER_DATA (field4->buf)) {
        /* telecine fields in separate buffers */
        GST_BUFFER_TIMESTAMP (field3->buf) =
            (GST_BUFFER_TIMESTAMP (field3->buf) +
            GST_BUFFER_TIMESTAMP (field4->buf)) / 2;
      }
    }

    GST_BUFFER_DURATION (field1->buf) =
        GST_BUFFER_TIMESTAMP (field3->buf) - GST_BUFFER_TIMESTAMP (field1->buf);
  }

  GST_DEBUG_OBJECT (self,
      "Field 1 adjusted to ts %" GST_TIME_FORMAT ", dur %" GST_TIME_FORMAT,
      GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (field1->buf)),
      GST_TIME_ARGS (GST_BUFFER_DURATION (field1->buf)));
  return TRUE;
}

static void
gst_deinterlace_get_pattern_lock (GstDeinterlace * self, gboolean * flush_one)
{
  /* loop over all possible patterns and all possible phases
   * giving each a score. the highest score gets the lock */
  /* the score is calculated as the number of matched buffers in the
   * sequence starting at the phase offset with those from the history
   * then the longest duration pattern match is taken. if there is more than
   * one pattern matching all buffers, we take the longest pattern of those.
   * matches to complete patterns are preferred. if no non-trivial pattern is
   * matched, trivial patterns are tested. */
  gint i, j, k, score, pattern, phase;
  const gint state_count = self->state_count;
  const gint n_required = self->ignore_obscure ?
      GST_DEINTERLACE_OBSCURE_THRESHOLD :
      GST_DEINTERLACE_MAX_BUFFER_STATE_HISTORY;

  /* set unknown pattern as this is used in logic outside this function */
  self->pattern = -1;

  /* wait for more buffers */
  if (!self->have_eos && state_count < n_required) {
    GST_DEBUG_OBJECT (self, "Need more buffers in state history - %d/%d",
        state_count, n_required);
    return;
  }

  score = pattern = phase = -1;

  /* loop over all patterns */
  for (i = 0; i < G_N_ELEMENTS (telecine_patterns); i++) {
    const guint8 length = telecine_patterns[i].length;

    if (self->ignore_obscure && i >= GST_DEINTERLACE_OBSCURE_THRESHOLD)
      break;

    if (state_count < length)
      continue;

    /* loop over all phases */
    for (j = 0; j < length; j++) {
      /* low-latency mode looks at past buffers, high latency at future buffers */
      const gint state_idx = (self->low_latency ? length : state_count) - 1;
      /* loop over history, breaking on differing buffer states */
      for (k = 0; k < length && k < state_count; k++) {
        const guint8 hist = self->buf_states[state_idx - k].state;
        const guint8 patt = telecine_patterns[i].states[(j + k) % length];
        if (!(hist & patt))
          break;
      }

      /* make complete matches more signficant */
      if (k == length)
        k += GST_DEINTERLACE_MAX_BUFFER_STATE_HISTORY;

      /* take as new best pattern if the number of matched buffers is more than
       * for other patterns */
      if (k > score) {
        score = k;
        pattern = i;
        phase = j;
        if (self->low_latency) {
          /* state_idx + 1 is the number of buffers yet to be pushed out
           * so length - state_idx - 1 is the number of old buffers in the
           * pattern */
          phase = (phase + length - state_idx - 1) % length;
        }
      }
    }
  }

  GST_DEBUG_OBJECT (self,
      "Final pattern match result: pa %d, ph %d, l %d, s %d", pattern, phase,
      telecine_patterns[pattern].length, score);
  self->pattern = pattern;
  self->pattern_phase = phase;
  self->pattern_count = 0;
  self->output_count = 0;
  self->pattern_lock = TRUE;

  /* check for the case that the first field of the pattern is an orphan */
  if (pattern > 1
      && telecine_patterns[pattern].states[phase] & (GST_ONE | GST_INT)) {
    gint i = phase, field_count = 0;
    guint8 state = telecine_patterns[pattern].states[i];

    do {
      if (state & GST_ONE) {
        field_count++;
      } else if (!(state & GST_DRP)) {
        field_count += 2;
      }
      i++;
      i %= telecine_patterns[pattern].length;
      state = telecine_patterns[pattern].states[i];
    } while (!(state & GST_PRG));

    /* if field_count is odd, we have an orphan field at the beginning of the
     * sequence
     * note - don't do this in low-latency mode as we are somewhere within the
     * pattern already */
    if (!self->low_latency && (*flush_one = field_count & 1)) {
      GST_DEBUG_OBJECT (self, "Orphan field detected at the beginning of the "
          "pattern - it will be deinterlaced.");
    }
  }
}

static GstFlowReturn
gst_deinterlace_output_frame (GstDeinterlace * self, gboolean flushing)
{
  GstClockTime timestamp;
  GstFlowReturn ret;
  gint fields_required;
  gint cur_field_idx;
  GstBuffer *buf, *outbuf;
  GstDeinterlaceField *field1, *field2;
  GstDeinterlaceInterlacingMethod interlacing_method;
  guint8 buf_state;
  gboolean hl_no_lock;          /* indicates high latency timestamp adjustment but no pattern lock (could be ONEF or I) */
  gboolean same_buffer;         /* are field1 and field2 in the same buffer? */
  gboolean flush_one;           /* used for flushing one field when in high latency mode and not locked */
  TelecinePattern pattern;
  guint8 phase, count;
  const GstDeinterlaceLocking locking = self->locking;

restart:
  ret = GST_FLOW_OK;
  fields_required = 0;
  cur_field_idx = 0;
  hl_no_lock = FALSE;
  same_buffer = FALSE;
  flush_one = FALSE;
  self->need_more = FALSE;
  phase = self->pattern_phase;
  count = self->pattern_count;

  if (!self->history_count) {
    GST_DEBUG_OBJECT (self, "History is empty, waiting for more buffers!");
    goto need_more;
  }

  field1 = &self->field_history[self->history_count - 1];

  if (locking != GST_DEINTERLACE_LOCKING_NONE) {
    if (!self->state_count) {
      GST_ERROR_OBJECT (self,
          "BROKEN! Fields in history + no states should not happen!");
      return GST_FLOW_ERROR;
    }

    gst_deinterlace_get_buffer_state (self, field1->buf, &buf_state,
        &interlacing_method);

    if (self->pattern != -1)
      pattern = telecine_patterns[self->pattern];

    /* patterns 0 and 1 are interlaced, the rest are telecine */
    if (self->pattern > 1)
      interlacing_method = GST_DEINTERLACE_TELECINE;

    if (self->pattern == -1 || self->pattern_refresh
        || !(buf_state & pattern.states[(phase + count) % pattern.length])) {
      /* no pattern, pattern refresh set or unexpected buffer state */
      self->pattern_lock = FALSE;
      self->pattern_refresh = TRUE;

      /* refresh pattern lock */
      gst_deinterlace_get_pattern_lock (self, &flush_one);

      if (self->pattern != -1) {
        /* locked onto a valid pattern so refresh complete */
        GST_DEBUG_OBJECT (self, "Pattern locked! %s starting at %d",
            telecine_patterns[self->pattern].nick, self->pattern_phase);
        self->pattern_refresh = FALSE;
      } else if (!self->low_latency) {
        if (!self->pattern_lock) {
          goto need_more;
        } else {
          hl_no_lock = TRUE;
        }
      }

      /* setcaps on sink and src pads */
      gst_deinterlace_setcaps (self->sinkpad, GST_PAD_CAPS (self->sinkpad));

      if (flush_one && self->drop_orphans) {
        GST_DEBUG_OBJECT (self, "Dropping orphan first field");
        gst_buffer_unref (gst_deinterlace_pop_history (self));
        goto restart;
      }
    }
  } else {
    gst_deinterlace_get_buffer_state (self, field1->buf, NULL,
        &interlacing_method);
  }

  same_buffer = self->history_count >= 2
      && (GST_BUFFER_DATA (field1->buf) ==
      GST_BUFFER_DATA (self->field_history[self->history_count - 2].buf));

  if ((flushing && self->history_count == 1) || (flush_one
          && !self->drop_orphans) || (hl_no_lock && (self->history_count == 1
              || !same_buffer))) {
    GST_DEBUG_OBJECT (self, "Flushing one field using linear method");
    gst_deinterlace_set_method (self, GST_DEINTERLACE_LINEAR);
    fields_required = gst_deinterlace_method_get_fields_required (self->method);
  } else if (interlacing_method == GST_DEINTERLACE_TELECINE
      && (self->low_latency > 0 || self->pattern != -1 || (hl_no_lock
              && same_buffer
              && GST_BUFFER_FLAG_IS_SET (field1->buf,
                  GST_VIDEO_BUFFER_PROGRESSIVE)))) {
    /* telecined - we reconstruct frames by weaving pairs of fields */
    fields_required = 2;
    if (!flushing && self->history_count < fields_required) {
      GST_DEBUG_OBJECT (self, "Need more fields (have %d, need %d)",
          self->history_count, fields_required);
      goto need_more;
    }

    field2 = &self->field_history[self->history_count - 2];
    if (!gst_deinterlace_fix_timestamps (self, field1, field2) && !flushing)
      goto need_more;

    if (same_buffer) {
      /* telecine progressive */
      GstBuffer *field1_buf;

      GST_DEBUG_OBJECT (self,
          "Frame type: Telecine Progressive; pushing buffer as a frame");
      /* pop and push */
      field1_buf = gst_deinterlace_pop_history (self);
      /* field2 is the same buffer as field1, but we need to remove it from
       * the history anyway */
      gst_buffer_unref (gst_deinterlace_pop_history (self));
      /* set the caps from the src pad on the buffer as they should be correct */
      gst_buffer_set_caps (field1_buf, GST_PAD_CAPS (self->srcpad));
      GST_DEBUG_OBJECT (self,
          "[OUT] ts %" GST_TIME_FORMAT ", dur %" GST_TIME_FORMAT ", end %"
          GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (field1_buf)),
          GST_TIME_ARGS (GST_BUFFER_DURATION (field1_buf)),
          GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (field1_buf) +
              GST_BUFFER_DURATION (field1_buf)));
      return gst_pad_push (self->srcpad, field1_buf);
    } else {
      /* telecine fields in separate buffers */

      /* check field1 and field2 buffer caps and flags are corresponding */
      if (field1->flags == field2->flags) {
        /* ERROR - fields are of same parity - what should be done here?
         * perhaps deinterlace the tip field and start again? */
        GST_ERROR_OBJECT (self, "Telecine mixed with fields of same parity!");
      }
      GST_DEBUG_OBJECT (self,
          "Frame type: Telecine Mixed; weaving tip two fields into a frame");
      /* set method to WEAVE */
      gst_deinterlace_set_method (self, GST_DEINTERLACE_WEAVE);
    }
  } else if (interlacing_method == GST_DEINTERLACE_INTERLACED || (hl_no_lock
          && interlacing_method == GST_DEINTERLACE_TELECINE && same_buffer
          && !GST_BUFFER_FLAG_IS_SET (field1->buf,
              GST_VIDEO_BUFFER_PROGRESSIVE))) {
    gst_deinterlace_set_method (self, self->user_set_method_id);
    fields_required = gst_deinterlace_method_get_fields_required (self->method);
    if (flushing && self->history_count < fields_required) {
      /* note: we already checked for flushing with history count == 1 above
       * so we must have 2 or more fields in here */
      gst_deinterlace_set_method (self, GST_DEINTERLACE_VFIR);
      fields_required =
          gst_deinterlace_method_get_fields_required (self->method);
      GST_DEBUG_OBJECT (self, "Flushing field(s) using %s method",
          methods_types[self->method_id].value_nick);
    }

    /* Not enough fields in the history */
    if (self->history_count < fields_required) {
      GST_DEBUG_OBJECT (self, "Need more fields (have %d, need %d)",
          self->history_count, fields_required);
      goto need_more;
    }

    GST_DEBUG_OBJECT (self,
        "Frame type: Interlaced; deinterlacing using %s method",
        methods_types[self->method_id].value_nick);
  } else {
    GstBuffer *field1_buf;

    /* progressive */
    fields_required = 2;

    /* Not enough fields in the history */
    if (self->history_count < fields_required) {
      GST_DEBUG_OBJECT (self, "Need more fields (have %d, need %d)",
          self->history_count, fields_required);
      goto need_more;
    }

    field2 = &self->field_history[self->history_count - 2];
    if (GST_BUFFER_DATA (field1->buf) != GST_BUFFER_DATA (field2->buf)) {
      /* ERROR - next two fields in field history are not one progressive buffer - weave? */
      GST_ERROR_OBJECT (self,
          "Progressive buffer but two fields at tip aren't in the same buffer!");
    }

    GST_DEBUG_OBJECT (self,
        "Frame type: Progressive; pushing buffer as a frame");
    /* pop and push */
    field1_buf = gst_deinterlace_pop_history (self);
    /* field2 is the same buffer as field1, but we need to remove it from the
     * history anyway */
    gst_buffer_unref (gst_deinterlace_pop_history (self));
    GST_DEBUG_OBJECT (self,
        "[OUT] ts %" GST_TIME_FORMAT ", dur %" GST_TIME_FORMAT ", end %"
        GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (field1_buf)),
        GST_TIME_ARGS (GST_BUFFER_DURATION (field1_buf)),
        GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (field1_buf) +
            GST_BUFFER_DURATION (field1_buf)));
    return gst_pad_push (self->srcpad, field1_buf);
  }

  if (self->fields == GST_DEINTERLACE_ALL
      || interlacing_method == GST_DEINTERLACE_TELECINE)
    GST_DEBUG_OBJECT (self, "All fields");
  else if (self->fields == GST_DEINTERLACE_TF)
    GST_DEBUG_OBJECT (self, "Top fields");
  else if (self->fields == GST_DEINTERLACE_BF)
    GST_DEBUG_OBJECT (self, "Bottom fields");

  cur_field_idx = self->history_count - fields_required;

  if ((self->field_history[cur_field_idx].flags == PICTURE_INTERLACED_TOP
          && (self->fields == GST_DEINTERLACE_TF
              || interlacing_method == GST_DEINTERLACE_TELECINE))
      || self->fields == GST_DEINTERLACE_ALL) {
    GST_DEBUG_OBJECT (self, "deinterlacing top field");

    /* create new buffer */
    ret =
        gst_pad_alloc_buffer (self->srcpad, GST_BUFFER_OFFSET_NONE,
        self->frame_size, GST_PAD_CAPS (self->srcpad), &outbuf);
    if (ret != GST_FLOW_OK)
      return ret;

    if (GST_PAD_CAPS (self->srcpad) != GST_BUFFER_CAPS (outbuf) &&
        !gst_caps_is_equal (GST_PAD_CAPS (self->srcpad),
            GST_BUFFER_CAPS (outbuf))) {
      gst_caps_replace (&self->request_caps, GST_BUFFER_CAPS (outbuf));
      GST_DEBUG_OBJECT (self, "Upstream wants new caps %" GST_PTR_FORMAT,
          self->request_caps);

      gst_buffer_unref (outbuf);
      outbuf = gst_buffer_try_new_and_alloc (self->frame_size);

      if (!outbuf)
        return GST_FLOW_ERROR;

      gst_buffer_set_caps (outbuf, GST_PAD_CAPS (self->srcpad));
    }

    g_return_val_if_fail (self->history_count - 1 -
        gst_deinterlace_method_get_latency (self->method) >= 0, GST_FLOW_ERROR);

    buf =
        self->field_history[self->history_count - 1 -
        gst_deinterlace_method_get_latency (self->method)].buf;

    if (interlacing_method != GST_DEINTERLACE_TELECINE) {
      timestamp = GST_BUFFER_TIMESTAMP (buf);

      GST_BUFFER_TIMESTAMP (outbuf) = timestamp;
      if (self->fields == GST_DEINTERLACE_ALL)
        GST_BUFFER_DURATION (outbuf) = self->field_duration;
      else
        GST_BUFFER_DURATION (outbuf) = 2 * self->field_duration;
    } else {
      GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buf);
      GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buf);
    }

    /* Check if we need to drop the frame because of QoS */
    if (!gst_deinterlace_do_qos (self, GST_BUFFER_TIMESTAMP (buf))) {
      gst_buffer_unref (gst_deinterlace_pop_history (self));
      gst_buffer_unref (outbuf);
      outbuf = NULL;
      ret = GST_FLOW_OK;
    } else {
      /* do magic calculus */
      gst_deinterlace_method_deinterlace_frame (self->method,
          self->field_history, self->history_count, outbuf);

      gst_buffer_unref (gst_deinterlace_pop_history (self));

      if (gst_deinterlace_clip_buffer (self, outbuf)) {
        GST_DEBUG_OBJECT (self,
            "[OUT] ts %" GST_TIME_FORMAT ", dur %" GST_TIME_FORMAT ", end %"
            GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf)),
            GST_TIME_ARGS (GST_BUFFER_DURATION (outbuf)),
            GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf) +
                GST_BUFFER_DURATION (outbuf)));
        ret = gst_pad_push (self->srcpad, outbuf);
      } else {
        ret = GST_FLOW_OK;
        gst_buffer_unref (outbuf);
      }

      outbuf = NULL;
      if (ret != GST_FLOW_OK)
        return ret;
      if (interlacing_method == GST_DEINTERLACE_TELECINE
          && self->method_id == GST_DEINTERLACE_WEAVE) {
        /* pop off the second field */
        GST_DEBUG_OBJECT (self, "Removing unused field (count: %d)",
            self->history_count);
        gst_buffer_unref (gst_deinterlace_pop_history (self));
        interlacing_method = GST_DEINTERLACE_INTERLACED;
        return ret;
      }
    }

    if (flush_one && !self->drop_orphans) {
      GST_DEBUG_OBJECT (self, "Orphan field deinterlaced - reconfiguring");
      goto restart;
    }
  }
  /* no calculation done: remove excess field */
  else if (self->field_history[cur_field_idx].flags ==
      PICTURE_INTERLACED_TOP && (self->fields == GST_DEINTERLACE_BF
          && interlacing_method != GST_DEINTERLACE_TELECINE)) {
    GST_DEBUG_OBJECT (self, "Removing unused top field");
    gst_buffer_unref (gst_deinterlace_pop_history (self));

    if (flush_one && !self->drop_orphans) {
      GST_DEBUG_OBJECT (self, "Orphan field deinterlaced - reconfiguring");
      goto restart;
    }
  }

  cur_field_idx = self->history_count - fields_required;
  if (self->history_count < fields_required)
    return ret;

  /* deinterlace bottom_field */
  if ((self->field_history[cur_field_idx].flags == PICTURE_INTERLACED_BOTTOM
          && (self->fields == GST_DEINTERLACE_BF
              || interlacing_method == GST_DEINTERLACE_TELECINE))
      || self->fields == GST_DEINTERLACE_ALL) {
    GST_DEBUG_OBJECT (self, "deinterlacing bottom field");

    /* create new buffer */
    ret =
        gst_pad_alloc_buffer (self->srcpad, GST_BUFFER_OFFSET_NONE,
        self->frame_size, GST_PAD_CAPS (self->srcpad), &outbuf);
    if (ret != GST_FLOW_OK)
      return ret;

    if (GST_PAD_CAPS (self->srcpad) != GST_BUFFER_CAPS (outbuf) &&
        !gst_caps_is_equal (GST_PAD_CAPS (self->srcpad),
            GST_BUFFER_CAPS (outbuf))) {
      gst_caps_replace (&self->request_caps, GST_BUFFER_CAPS (outbuf));
      GST_DEBUG_OBJECT (self, "Upstream wants new caps %" GST_PTR_FORMAT,
          self->request_caps);

      gst_buffer_unref (outbuf);
      outbuf = gst_buffer_try_new_and_alloc (self->frame_size);

      if (!outbuf)
        return GST_FLOW_ERROR;

      gst_buffer_set_caps (outbuf, GST_PAD_CAPS (self->srcpad));
    }

    g_return_val_if_fail (self->history_count - 1 -
        gst_deinterlace_method_get_latency (self->method) >= 0, GST_FLOW_ERROR);

    buf =
        self->field_history[self->history_count - 1 -
        gst_deinterlace_method_get_latency (self->method)].buf;
    if (interlacing_method != GST_DEINTERLACE_TELECINE) {
      timestamp = GST_BUFFER_TIMESTAMP (buf);

      GST_BUFFER_TIMESTAMP (outbuf) = timestamp;
      if (self->fields == GST_DEINTERLACE_ALL)
        GST_BUFFER_DURATION (outbuf) = self->field_duration;
      else
        GST_BUFFER_DURATION (outbuf) = 2 * self->field_duration;
    } else {
      GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buf);
      GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buf);
    }

    /* Check if we need to drop the frame because of QoS */
    if (!gst_deinterlace_do_qos (self, GST_BUFFER_TIMESTAMP (buf))) {
      gst_buffer_unref (gst_deinterlace_pop_history (self));
      gst_buffer_unref (outbuf);
      outbuf = NULL;
      ret = GST_FLOW_OK;
    } else {
      /* do magic calculus */
      gst_deinterlace_method_deinterlace_frame (self->method,
          self->field_history, self->history_count, outbuf);

      gst_buffer_unref (gst_deinterlace_pop_history (self));

      if (gst_deinterlace_clip_buffer (self, outbuf)) {
        GST_DEBUG_OBJECT (self,
            "[OUT] ts %" GST_TIME_FORMAT ", dur %" GST_TIME_FORMAT ", end %"
            GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf)),
            GST_TIME_ARGS (GST_BUFFER_DURATION (outbuf)),
            GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf) +
                GST_BUFFER_DURATION (outbuf)));
        ret = gst_pad_push (self->srcpad, outbuf);
      } else {
        ret = GST_FLOW_OK;
        gst_buffer_unref (outbuf);
      }

      outbuf = NULL;
      if (ret != GST_FLOW_OK)
        return ret;
      if (interlacing_method == GST_DEINTERLACE_TELECINE
          && self->method_id == GST_DEINTERLACE_WEAVE) {
        /* pop off the second field */
        GST_DEBUG_OBJECT (self, "Removing unused field (count: %d)",
            self->history_count);
        gst_buffer_unref (gst_deinterlace_pop_history (self));
        interlacing_method = GST_DEINTERLACE_INTERLACED;
        return ret;
      }
    }

    if (flush_one && !self->drop_orphans) {
      GST_DEBUG_OBJECT (self, "Orphan field deinterlaced - reconfiguring");
      goto restart;
    }
  }
  /* no calculation done: remove excess field */
  else if (self->field_history[cur_field_idx].flags ==
      PICTURE_INTERLACED_BOTTOM && (self->fields == GST_DEINTERLACE_TF
          && interlacing_method != GST_DEINTERLACE_TELECINE)) {
    GST_DEBUG_OBJECT (self, "Removing unused bottom field");
    gst_buffer_unref (gst_deinterlace_pop_history (self));

    if (flush_one && !self->drop_orphans) {
      GST_DEBUG_OBJECT (self, "Orphan field deinterlaced - reconfiguring");
      goto restart;
    }
  }

  return ret;

need_more:
  self->need_more = TRUE;
  return ret;
}

static gboolean
gst_deinterlace_get_latency (GstDeinterlace * self)
{
  if (self->locking == GST_DEINTERLACE_LOCKING_AUTO) {
    gboolean res;
    GstQuery *query;

    query = gst_query_new_latency ();
    if ((res = gst_pad_peer_query (self->sinkpad, query))) {
      gboolean is_live;
      /* if upstream is live, we use low-latency passive locking mode
       * else high-latency active locking mode */
      gst_query_parse_latency (query, &is_live, NULL, NULL);
      GST_DEBUG_OBJECT (self, "Latency query indicates stream is %s",
          is_live ? "live - using passive locking" :
          "not live - using active locking");
      gst_query_unref (query);
      return is_live;
    } else {
      /* conservatively use passive locking if the query fails */
      GST_WARNING_OBJECT (self,
          "Latency query failed - fall back to using passive locking");
      gst_query_unref (query);
      return TRUE;
    }
  } else {
    return self->locking - 2;
  }
}

static GstFlowReturn
gst_deinterlace_chain (GstPad * pad, GstBuffer * buf)
{
  GstDeinterlace *self = GST_DEINTERLACE (GST_PAD_PARENT (pad));
  GstFlowReturn ret = GST_FLOW_OK;

  GST_OBJECT_LOCK (self);
  if (self->reconfigure) {
    if (self->new_fields != -1)
      self->fields = self->new_fields;
    if (self->new_mode != -1)
      self->mode = self->new_mode;
    self->new_mode = self->new_fields = -1;

    self->reconfigure = FALSE;
    GST_OBJECT_UNLOCK (self);
    if (GST_PAD_CAPS (self->srcpad))
      gst_deinterlace_setcaps (self->sinkpad, GST_PAD_CAPS (self->sinkpad));
  } else {
    GST_OBJECT_UNLOCK (self);
  }

  GST_DEBUG_OBJECT (self,
      "[IN] ts %" GST_TIME_FORMAT ", dur %" GST_TIME_FORMAT ", end %"
      GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)),
      GST_TIME_ARGS (GST_BUFFER_DURATION (buf)),
      GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf) + GST_BUFFER_DURATION (buf)));

  if (self->still_frame_mode || self->passthrough) {
    GST_DEBUG_OBJECT (self,
        "Frame type: Progressive?; pushing buffer using pass-through");
    GST_DEBUG_OBJECT (self,
        "[OUT] ts %" GST_TIME_FORMAT ", dur %" GST_TIME_FORMAT ", end %"
        GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)),
        GST_TIME_ARGS (GST_BUFFER_DURATION (buf)),
        GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf) + GST_BUFFER_DURATION (buf)));

    return gst_pad_push (self->srcpad, buf);
  }

  if (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_DISCONT)) {
    GST_DEBUG_OBJECT (self, "DISCONT buffer, resetting history");
    gst_deinterlace_reset_history (self, FALSE);
  }

  gst_deinterlace_push_history (self, buf);
  buf = NULL;

  do {
    ret = gst_deinterlace_output_frame (self, FALSE);
  } while (!self->need_more && self->history_count > 0 && ret == GST_FLOW_OK);

  return ret;
}

static gint
gst_greatest_common_divisor (gint a, gint b)
{
  while (b != 0) {
    int temp = a;

    a = b;
    b = temp % b;
  }

  return ABS (a);
}

static gboolean
gst_fraction_double (gint * n_out, gint * d_out, gboolean half)
{
  gint n, d, gcd;

  n = *n_out;
  d = *d_out;

  if (d == 0)
    return FALSE;

  if (n == 0 || (n == G_MAXINT && d == 1))
    return TRUE;

  gcd = gst_greatest_common_divisor (n, d);
  n /= gcd;
  d /= gcd;

  if (!half) {
    if (G_MAXINT / 2 >= ABS (n)) {
      n *= 2;
    } else if (d >= 2) {
      d /= 2;
    } else {
      return FALSE;
    }
  } else {
    if (G_MAXINT / 2 >= ABS (d)) {
      d *= 2;
    } else if (n >= 2) {
      n /= 2;
    } else {
      return FALSE;
    }
  }

  *n_out = n;
  *d_out = d;

  return TRUE;
}

static GstCaps *
gst_deinterlace_getcaps (GstPad * pad)
{
  GstCaps *ret;
  GstDeinterlace *self = GST_DEINTERLACE (gst_pad_get_parent (pad));
  GstPad *otherpad;
  gint len;
  const GstCaps *ourcaps;
  GstCaps *peercaps;

  GST_OBJECT_LOCK (self);

  otherpad = (pad == self->srcpad) ? self->sinkpad : self->srcpad;

  ourcaps = gst_pad_get_pad_template_caps (pad);
  peercaps = gst_pad_peer_get_caps (otherpad);

  if (peercaps) {
    GST_DEBUG_OBJECT (pad, "Peer has caps %" GST_PTR_FORMAT, peercaps);
    ret = gst_caps_intersect (ourcaps, peercaps);
    gst_caps_unref (peercaps);
  } else {
    ret = gst_caps_copy (ourcaps);
  }

  GST_OBJECT_UNLOCK (self);

  for (len = gst_caps_get_size (ret); len > 0; len--) {
    GstStructure *s = gst_caps_get_structure (ret, len - 1);

    if (pad == self->sinkpad || self->passthrough)
      gst_structure_remove_field (s, "interlaced");
    else
      gst_structure_set (s, "interlaced", G_TYPE_BOOLEAN, FALSE, NULL);

    if (!self->passthrough && self->fields == GST_DEINTERLACE_ALL) {
      const GValue *val;

      val = gst_structure_get_value (s, "framerate");
      if (!val)
        continue;

      if (G_VALUE_TYPE (val) == GST_TYPE_FRACTION) {
        gint n, d;

        n = gst_value_get_fraction_numerator (val);
        d = gst_value_get_fraction_denominator (val);

        if (!gst_fraction_double (&n, &d, pad != self->srcpad)) {
          goto error;
        }

        gst_structure_set (s, "framerate", GST_TYPE_FRACTION, n, d, NULL);
      } else if (G_VALUE_TYPE (val) == GST_TYPE_FRACTION_RANGE) {
        const GValue *min, *max;
        GValue nrange = { 0, }, nmin = {
        0,}, nmax = {
        0,};
        gint n, d;

        g_value_init (&nrange, GST_TYPE_FRACTION_RANGE);
        g_value_init (&nmin, GST_TYPE_FRACTION);
        g_value_init (&nmax, GST_TYPE_FRACTION);

        min = gst_value_get_fraction_range_min (val);
        max = gst_value_get_fraction_range_max (val);

        n = gst_value_get_fraction_numerator (min);
        d = gst_value_get_fraction_denominator (min);

        if (!gst_fraction_double (&n, &d, pad != self->srcpad)) {
          g_value_unset (&nrange);
          g_value_unset (&nmax);
          g_value_unset (&nmin);
          goto error;
        }

        gst_value_set_fraction (&nmin, n, d);

        n = gst_value_get_fraction_numerator (max);
        d = gst_value_get_fraction_denominator (max);

        if (!gst_fraction_double (&n, &d, pad != self->srcpad)) {
          g_value_unset (&nrange);
          g_value_unset (&nmax);
          g_value_unset (&nmin);
          goto error;
        }

        gst_value_set_fraction (&nmax, n, d);
        gst_value_set_fraction_range (&nrange, &nmin, &nmax);

        gst_structure_set_value (s, "framerate", &nrange);

        g_value_unset (&nmin);
        g_value_unset (&nmax);
        g_value_unset (&nrange);
      } else if (G_VALUE_TYPE (val) == GST_TYPE_LIST) {
        const GValue *lval;
        GValue nlist = { 0, };
        GValue nval = { 0, };
        gint i;

        g_value_init (&nlist, GST_TYPE_LIST);
        for (i = gst_value_list_get_size (val); i > 0; i--) {
          gint n, d;

          lval = gst_value_list_get_value (val, i);

          if (G_VALUE_TYPE (lval) != GST_TYPE_FRACTION)
            continue;

          n = gst_value_get_fraction_numerator (lval);
          d = gst_value_get_fraction_denominator (lval);

          /* Double/Half the framerate but if this fails simply
           * skip this value from the list */
          if (!gst_fraction_double (&n, &d, pad != self->srcpad)) {
            continue;
          }

          g_value_init (&nval, GST_TYPE_FRACTION);

          gst_value_set_fraction (&nval, n, d);
          gst_value_list_append_value (&nlist, &nval);
          g_value_unset (&nval);
        }
        gst_structure_set_value (s, "framerate", &nlist);
        g_value_unset (&nlist);
      }
    }
  }

  GST_DEBUG_OBJECT (pad, "Returning caps %" GST_PTR_FORMAT, ret);

  gst_object_unref (self);

  return ret;

error:
  GST_ERROR_OBJECT (pad, "Unable to transform peer caps");
  gst_caps_unref (ret);
  return NULL;
}

static gboolean
gst_deinterlace_setcaps (GstPad * pad, GstCaps * caps)
{
  gboolean res = TRUE;
  GstDeinterlace *self = GST_DEINTERLACE (gst_pad_get_parent (pad));
  GstCaps *srccaps;
  GstDeinterlaceInterlacingMethod interlacing_method;

  if (self->locking != GST_DEINTERLACE_LOCKING_NONE) {
    if (self->low_latency == -1)
      self->low_latency = gst_deinterlace_get_latency (self);

    if (self->pattern_lock) {
      /* refresh has been successful - we have a lock now */
      self->pattern_refresh = FALSE;
    } else {
      /* if we were not refreshing (!pattern_refresh) the caps have changed
       * so we need to refresh and we don't have a lock anymore
       * otherwise we have pattern_fresh and !pattern_lock anyway */
      self->pattern_refresh = TRUE;
      self->pattern_lock = FALSE;
    }
  }

  res =
      gst_video_format_parse_caps (caps, &self->format, &self->width,
      &self->height);
  res &= gst_video_parse_caps_framerate (caps, &self->fps_n, &self->fps_d);
  if (pad == self->sinkpad)
    res &= gst_video_format_parse_caps_interlaced (caps, &self->interlaced);
  if (!res)
    goto invalid_caps;

  gst_deinterlace_update_passthrough (self);

  interlacing_method = gst_deinterlace_get_interlacing_method (caps);

  if (self->pattern_lock) {
    srccaps = gst_caps_copy (caps);
    if (self->pattern != -1
        && G_UNLIKELY (!gst_util_fraction_multiply (self->fps_n, self->fps_d,
                telecine_patterns[self->pattern].ratio_n,
                telecine_patterns[self->pattern].ratio_d, &self->fps_n,
                &self->fps_d)))
      GST_ERROR_OBJECT (self,
          "Multiplying the framerate by the telecine pattern ratio overflowed!");
    gst_caps_set_simple (srccaps, "framerate", GST_TYPE_FRACTION, self->fps_n,
        self->fps_d, NULL);
  } else if (self->low_latency > 0) {
    if (interlacing_method == GST_DEINTERLACE_TELECINE) {
      /* for initial buffers of a telecine pattern, until there is a lock we
       * we output naïvely adjusted timestamps */
      srccaps = gst_caps_copy (caps);
      gst_caps_set_simple (srccaps, "framerate", GST_TYPE_FRACTION, 0, 1, NULL);
    } else if (!self->passthrough && self->fields == GST_DEINTERLACE_ALL) {
      gint fps_n = self->fps_n, fps_d = self->fps_d;

      if (!gst_fraction_double (&fps_n, &fps_d, FALSE))
        goto invalid_caps;

      srccaps = gst_caps_copy (caps);

      gst_caps_set_simple (srccaps, "framerate", GST_TYPE_FRACTION, fps_n,
          fps_d, NULL);
    } else {
      srccaps = gst_caps_ref (caps);
    }
  } else {
    /* in high latency pattern locking mode if we don't have a pattern lock,
     * the sink pad caps are the best we know */
    srccaps = gst_caps_ref (caps);
  }

  if (self->mode != GST_DEINTERLACE_MODE_DISABLED) {
    srccaps = gst_caps_make_writable (srccaps);
    gst_structure_remove_field (gst_caps_get_structure (srccaps, 0),
        "interlacing-method");
    gst_caps_set_simple (srccaps, "interlaced", G_TYPE_BOOLEAN, FALSE, NULL);
  }

  if (!gst_pad_set_caps (self->srcpad, srccaps))
    goto caps_not_accepted;

  self->frame_size =
      gst_video_format_get_size (self->format, self->width, self->height);

  if (G_LIKELY (self->fps_n != 0)) {
    self->field_duration =
        gst_util_uint64_scale (GST_SECOND, self->fps_d, 2 * self->fps_n);
  } else {
    self->field_duration = 0;
  }

  gst_deinterlace_set_method (self, self->method_id);
  gst_deinterlace_method_setup (self->method, self->format, self->width,
      self->height);

  GST_DEBUG_OBJECT (pad, "Sink caps: %" GST_PTR_FORMAT, caps);
  GST_DEBUG_OBJECT (pad, "Src  caps: %" GST_PTR_FORMAT, srccaps);

  gst_caps_unref (srccaps);

done:

  gst_object_unref (self);
  return res;

invalid_caps:
  res = FALSE;
  GST_ERROR_OBJECT (pad, "Invalid caps: %" GST_PTR_FORMAT, caps);
  goto done;

caps_not_accepted:
  res = FALSE;
  GST_ERROR_OBJECT (pad, "Caps not accepted: %" GST_PTR_FORMAT, srccaps);
  gst_caps_unref (srccaps);
  goto done;
}

static gboolean
gst_deinterlace_sink_event (GstPad * pad, GstEvent * event)
{
  gboolean res = TRUE;
  GstDeinterlace *self = GST_DEINTERLACE (gst_pad_get_parent (pad));

  GST_LOG_OBJECT (pad, "received %s event: %" GST_PTR_FORMAT,
      GST_EVENT_TYPE_NAME (event), event);

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_NEWSEGMENT:
    {
      GstFormat fmt;
      gboolean is_update;
      gint64 start, end, base;
      gdouble rate, applied_rate;

      gst_event_parse_new_segment_full (event, &is_update, &rate,
          &applied_rate, &fmt, &start, &end, &base);

      gst_deinterlace_reset_qos (self);
      gst_deinterlace_reset_history (self, FALSE);

      if (fmt == GST_FORMAT_TIME) {
        GST_DEBUG_OBJECT (pad,
            "Got NEWSEGMENT event in GST_FORMAT_TIME, passing on (%"
            GST_TIME_FORMAT " - %" GST_TIME_FORMAT ")", GST_TIME_ARGS (start),
            GST_TIME_ARGS (end));
        gst_segment_set_newsegment_full (&self->segment, is_update, rate,
            applied_rate, fmt, start, end, base);
      } else {
        gst_segment_init (&self->segment, GST_FORMAT_UNDEFINED);
      }

      res = gst_pad_push_event (self->srcpad, event);
      break;
    }
    case GST_EVENT_CUSTOM_DOWNSTREAM:{
      gboolean still_state;

      if (gst_video_event_parse_still_frame (event, &still_state)) {
        GST_DEBUG_OBJECT (self, "Received still frame event, state %d",
            still_state);

        if (still_state) {
          GstFlowReturn ret;

          GST_DEBUG_OBJECT (self, "Handling still frame");
          self->still_frame_mode = TRUE;
          gst_deinterlace_reset_history (self, FALSE);
          if (self->last_buffer) {
            ret =
                gst_pad_push (self->srcpad, gst_buffer_ref (self->last_buffer));
            GST_DEBUG_OBJECT (self, "Pushed still frame, result: %s",
                gst_flow_get_name (ret));
          } else {
            GST_WARNING_OBJECT (self, "No pending buffer!");
          }
        } else {
          GST_DEBUG_OBJECT (self, "Ending still frames");
          self->still_frame_mode = FALSE;
        }
      }
    }
      /* fall through */
    case GST_EVENT_EOS:
      self->have_eos = TRUE;
      gst_deinterlace_reset_history (self, FALSE);

      /* fall through */
    default:
      res = gst_pad_push_event (self->srcpad, event);
      break;

    case GST_EVENT_FLUSH_STOP:
      if (self->still_frame_mode) {
        GST_DEBUG_OBJECT (self, "Ending still frames");
        self->still_frame_mode = FALSE;
      }
      gst_deinterlace_reset_qos (self);
      res = gst_pad_push_event (self->srcpad, event);
      gst_deinterlace_reset_history (self, TRUE);
      break;
  }

  gst_object_unref (self);
  return res;
}

static gboolean
gst_deinterlace_sink_query (GstPad * pad, GstQuery * query)
{
  GstDeinterlace *self = GST_DEINTERLACE (gst_pad_get_parent (pad));
  gboolean res = FALSE;

  GST_LOG_OBJECT (pad, "%s query", GST_QUERY_TYPE_NAME (query));

  switch (GST_QUERY_TYPE (query)) {
    default:{
      GstPad *peer = gst_pad_get_peer (self->srcpad);

      if (peer) {
        res = gst_pad_query (peer, query);
        gst_object_unref (peer);
      } else {
        res = FALSE;
      }
      break;
    }
  }

  gst_object_unref (self);
  return res;
}

static GstStateChangeReturn
gst_deinterlace_change_state (GstElement * element, GstStateChange transition)
{
  GstStateChangeReturn ret;
  GstDeinterlace *self = GST_DEINTERLACE (element);

  switch (transition) {
    case GST_STATE_CHANGE_NULL_TO_READY:
      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:
      gst_deinterlace_reset (self);
      break;
    case GST_STATE_CHANGE_READY_TO_NULL:
    default:
      break;
  }

  return ret;
}

static gboolean
gst_deinterlace_src_event (GstPad * pad, GstEvent * event)
{
  GstDeinterlace *self = GST_DEINTERLACE (gst_pad_get_parent (pad));
  gboolean res;

  GST_DEBUG_OBJECT (pad, "received %s event", GST_EVENT_TYPE_NAME (event));

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_QOS:{
      GstClockTimeDiff diff;
      GstClockTime timestamp;
      gdouble proportion;

      gst_event_parse_qos (event, &proportion, &diff, &timestamp);

      gst_deinterlace_update_qos (self, proportion, diff, timestamp);
    }
      /* fall through */
    default:
      res = gst_pad_push_event (self->sinkpad, event);
      break;
  }

  gst_object_unref (self);

  return res;
}

static gboolean
gst_deinterlace_src_query (GstPad * pad, GstQuery * query)
{
  GstDeinterlace *self = GST_DEINTERLACE (gst_pad_get_parent (pad));
  gboolean res = FALSE;

  GST_LOG_OBJECT (pad, "%s query", GST_QUERY_TYPE_NAME (query));

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_LATENCY:
      if (!self->passthrough) {
        GstClockTime min, max;
        gboolean live;
        GstPad *peer;

        if ((peer = gst_pad_get_peer (self->sinkpad))) {
          if ((res = gst_pad_query (peer, query))) {
            GstClockTime latency;
            gint fields_required = 0;
            gint method_latency = 0;

            if (self->method) {
              fields_required =
                  gst_deinterlace_method_get_fields_required (self->method);
              method_latency =
                  gst_deinterlace_method_get_latency (self->method);
            }

            gst_query_parse_latency (query, &live, &min, &max);

            GST_DEBUG_OBJECT (self, "Peer latency: min %"
                GST_TIME_FORMAT " max %" GST_TIME_FORMAT,
                GST_TIME_ARGS (min), GST_TIME_ARGS (max));

            /* add our own latency */
            latency = (fields_required + method_latency) * self->field_duration;

            GST_DEBUG_OBJECT (self, "Our latency: min %" GST_TIME_FORMAT
                ", max %" GST_TIME_FORMAT,
                GST_TIME_ARGS (latency), GST_TIME_ARGS (latency));

            min += latency;
            if (max != GST_CLOCK_TIME_NONE)
              max += latency;

            GST_DEBUG_OBJECT (self, "Calculated total latency : min %"
                GST_TIME_FORMAT " max %" GST_TIME_FORMAT,
                GST_TIME_ARGS (min), GST_TIME_ARGS (max));

            gst_query_set_latency (query, live, min, max);
          }
          gst_object_unref (peer);
        } else {
          res = FALSE;
        }
        break;
      }
    default:{
      GstPad *peer = gst_pad_get_peer (self->sinkpad);

      if (peer) {
        res = gst_pad_query (peer, query);
        gst_object_unref (peer);
      } else {
        res = FALSE;
      }
      break;
    }
  }

  gst_object_unref (self);
  return res;
}

static const GstQueryType *
gst_deinterlace_src_query_types (GstPad * pad)
{
  static const GstQueryType types[] = {
    GST_QUERY_LATENCY,
    GST_QUERY_NONE
  };
  return types;
}

static GstFlowReturn
gst_deinterlace_alloc_buffer (GstPad * pad, guint64 offset, guint size,
    GstCaps * caps, GstBuffer ** buf)
{
  GstDeinterlace *self = GST_DEINTERLACE (gst_pad_get_parent (pad));
  GstFlowReturn ret = GST_FLOW_OK;

  *buf = NULL;

  GST_DEBUG_OBJECT (pad, "alloc with caps %" GST_PTR_FORMAT ", size %u", caps,
      size);

  if (self->still_frame_mode || self->passthrough) {
    ret = gst_pad_alloc_buffer (self->srcpad, offset, size, caps, buf);
  } else if (G_LIKELY (!self->request_caps)) {
    *buf = gst_buffer_try_new_and_alloc (size);
    if (G_UNLIKELY (!*buf)) {
      ret = GST_FLOW_ERROR;
    } else {
      gst_buffer_set_caps (*buf, caps);
      GST_BUFFER_OFFSET (*buf) = offset;
    }
  } else {
    gint width, height;
    GstVideoFormat fmt;
    guint new_frame_size;
    GstCaps *new_caps = gst_caps_copy (self->request_caps);

    if (self->fields == GST_DEINTERLACE_ALL) {
      gint n, d;
      GstStructure *s = gst_caps_get_structure (new_caps, 0);

      gst_structure_get_fraction (s, "framerate", &n, &d);

      if (!gst_fraction_double (&n, &d, TRUE)) {
        gst_object_unref (self);
        gst_caps_unref (new_caps);
        return GST_FLOW_OK;
      }

      gst_structure_set (s, "framerate", GST_TYPE_FRACTION, n, d, NULL);
    }

    if (G_UNLIKELY (!gst_video_format_parse_caps (new_caps, &fmt, &width,
                &height))) {
      gst_object_unref (self);
      gst_caps_unref (new_caps);
      return GST_FLOW_OK;
    }

    new_frame_size = gst_video_format_get_size (fmt, width, height);

    *buf = gst_buffer_try_new_and_alloc (new_frame_size);
    if (G_UNLIKELY (!*buf)) {
      ret = GST_FLOW_ERROR;
    } else {
      gst_buffer_set_caps (*buf, new_caps);
      gst_caps_unref (self->request_caps);
      self->request_caps = NULL;
      gst_caps_unref (new_caps);
    }
  }

  gst_object_unref (self);

  return ret;
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  GST_DEBUG_CATEGORY_INIT (deinterlace_debug, "deinterlace", 0, "Deinterlacer");

#if HAVE_ORC
  orc_init ();
#endif

  if (!gst_element_register (plugin, "deinterlace", GST_RANK_NONE,
          GST_TYPE_DEINTERLACE)) {
    return FALSE;
  }

  return TRUE;
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    "deinterlace",
    "Deinterlacer", plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME,
    GST_PACKAGE_ORIGIN);