gstreamer/ext/dv/gstdvdec.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *               <2005> Wim Taymans <wim@fluendo.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <math.h>

/* First, include the header file for the plugin, to bring in the
 * object definition and other useful things.
 */
#include "gstdvdec.h"

/* DV output has two modes, normal and wide. The resolution is the same in both
 * cases: 720 pixels wide by 576 pixels tall in PAL format, and 720x480 for
 * NTSC.
 *
 * Each of the modes has its own pixel aspect ratio, which is fixed in practice
 * by ITU-R BT.601 (also known as "CCIR-601" or "Rec.601"). Or so claims a
 * reference that I culled from the reliable "internet",
 * http://www.mir.com/DMG/aspect.html. Normal PAL is 59/54 and normal NTSC is
 * 10/11. Because the pixel resolution is the same for both cases, we can get
 * the pixel aspect ratio for wide recordings by multiplying by the ratio of
 * display aspect ratios, 16/9 (for wide) divided by 4/3 (for normal):
 *
 * Wide NTSC: 10/11 * (16/9)/(4/3) = 40/33
 * Wide PAL: 59/54 * (16/9)/(4/3) = 118/81
 *
 * However, the pixel resolution coming out of a DV source does not combine with
 * the standard pixel aspect ratios to give a proper display aspect ratio. An
 * image 480 pixels tall, with a 4:3 display aspect ratio, will be 768 pixels
 * wide. But, if we take the normal PAL aspect ratio of 59/54, and multiply it
 * with the width of the DV image (720 pixels), we get 786.666..., which is
 * nonintegral and too wide. The camera is not outputting a 4:3 image.
 * 
 * If the video sink for this stream has fixed dimensions (such as for
 * fullscreen playback, or for a java applet in a web page), you then have two
 * choices. Either you show the whole image, but pad the image with black
 * borders on the top and bottom (like watching a widescreen video on a 4:3
 * device), or you crop the video to the proper ratio. Apparently the latter is
 * the standard practice.
 *
 * For its part, GStreamer is concerned with accuracy and preservation of
 * information. This element outputs the 720x576 or 720x480 video that it
 * recieves, noting the proper aspect ratio. This should not be a problem for
 * windowed applications, which can change size to fit the video. Applications
 * with fixed size requirements should decide whether to crop or pad which
 * an element such as videobox can do.
 */

#define NTSC_HEIGHT 480
#define NTSC_BUFFER 120000
#define NTSC_FRAMERATE 30000/1001.

#define PAL_HEIGHT 576
#define PAL_BUFFER 144000
#define PAL_FRAMERATE 25.0

#define PAL_NORMAL_PAR_X	59
#define PAL_NORMAL_PAR_Y	54
#define PAL_WIDE_PAR_X		118
#define PAL_WIDE_PAR_Y		81

#define NTSC_NORMAL_PAR_X	10
#define NTSC_NORMAL_PAR_Y	11
#define NTSC_WIDE_PAR_X		40
#define NTSC_WIDE_PAR_Y		33

/* The ElementDetails structure gives a human-readable description
 * of the plugin, as well as author and version data.
 */
static GstElementDetails dvdec_details =
GST_ELEMENT_DETAILS ("DV (smpte314) decoder plugin",
    "Codec/Decoder/Video",
    "Uses libdv to decode DV video (libdv.sourceforge.net)",
    "Erik Walthinsen <omega@cse.ogi.edu>," "Wim Taymans <wim@fluendo.com>");


/* These are the signals that this element can fire.  They are zero-
 * based because the numbers themselves are private to the object.
 * LAST_SIGNAL is used for initialization of the signal array.
 */
enum
{
  /* FILL ME */
  LAST_SIGNAL
};

#define DV_DEFAULT_QUALITY DV_QUALITY_BEST
#define DV_DEFAULT_DECODE_NTH 1

/* Arguments are identified the same way, but cannot be zero, so you
 * must leave the ARG_0 entry in as a placeholder.
 */
enum
{
  ARG_0,
  ARG_CLAMP_LUMA,
  ARG_CLAMP_CHROMA,
  ARG_QUALITY,
  ARG_DECODE_NTH
      /* FILL ME */
};

const gint qualities[] = {
  DV_QUALITY_DC,
  DV_QUALITY_AC_1,
  DV_QUALITY_AC_2,
  DV_QUALITY_DC | DV_QUALITY_COLOR,
  DV_QUALITY_AC_1 | DV_QUALITY_COLOR,
  DV_QUALITY_AC_2 | DV_QUALITY_COLOR
};

/* The PadFactory structures describe what pads the element has or
 * can have.  They can be quite complex, but for this dvdec plugin
 * they are rather simple.
 */
static GstStaticPadTemplate sink_temp = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("video/x-dv, systemstream = (boolean) true")
    );

static GstStaticPadTemplate video_src_temp = GST_STATIC_PAD_TEMPLATE ("video",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("video/x-raw-yuv, "
        "format = (fourcc) YUY2, "
        "width = (int) 720, "
        "height = (int) { "
        G_STRINGIFY (NTSC_HEIGHT) ", " G_STRINGIFY (PAL_HEIGHT)
        " }, "
        "pixel-aspect-ratio=(fraction) { "
        G_STRINGIFY (PAL_NORMAL_PAR_X) "/" G_STRINGIFY (PAL_NORMAL_PAR_Y) ","
        G_STRINGIFY (PAL_WIDE_PAR_X) "/" G_STRINGIFY (PAL_WIDE_PAR_Y) ","
        G_STRINGIFY (NTSC_NORMAL_PAR_X) "/" G_STRINGIFY (NTSC_NORMAL_PAR_Y) ","
        G_STRINGIFY (NTSC_WIDE_PAR_X) "/" G_STRINGIFY (NTSC_WIDE_PAR_Y) "},"
        "framerate = (double) [ 1.0, 60.0 ];"
        "video/x-raw-rgb, "
        "bpp = (int) 32, "
        "depth = (int) 24, "
        "endianness = (int) " G_STRINGIFY (G_BIG_ENDIAN) ", "
        "red_mask =   (int) 0x0000ff00, "
        "green_mask = (int) 0x00ff0000, "
        "blue_mask =  (int) 0xff000000, "
        "width = (int) 720, "
        "height = (int) { "
        G_STRINGIFY (NTSC_HEIGHT) ", " G_STRINGIFY (PAL_HEIGHT)
        " }, "
        "pixel-aspect-ratio=(fraction) { "
        G_STRINGIFY (PAL_NORMAL_PAR_X) "/" G_STRINGIFY (PAL_NORMAL_PAR_Y) ","
        G_STRINGIFY (PAL_WIDE_PAR_X) "/" G_STRINGIFY (PAL_WIDE_PAR_Y) ","
        G_STRINGIFY (NTSC_NORMAL_PAR_X) "/" G_STRINGIFY (NTSC_NORMAL_PAR_Y) ","
        G_STRINGIFY (NTSC_WIDE_PAR_X) "/" G_STRINGIFY (NTSC_WIDE_PAR_Y) "},"
        "framerate = (double) [ 1.0, 60.0 ];"
        "video/x-raw-rgb, "
        "bpp = (int) 24, "
        "depth = (int) 24, "
        "endianness = (int) " G_STRINGIFY (G_BIG_ENDIAN) ", "
        "red_mask =   (int) 0x00ff0000, "
        "green_mask = (int) 0x0000ff00, "
        "blue_mask =  (int) 0x000000ff, "
        "width = (int) 720, "
        "height = (int) { "
        G_STRINGIFY (NTSC_HEIGHT) ", " G_STRINGIFY (PAL_HEIGHT)
        " }, "
        "pixel-aspect-ratio=(fraction) { "
        G_STRINGIFY (PAL_NORMAL_PAR_X) "/" G_STRINGIFY (PAL_NORMAL_PAR_Y) ","
        G_STRINGIFY (PAL_WIDE_PAR_X) "/" G_STRINGIFY (PAL_WIDE_PAR_Y) ","
        G_STRINGIFY (NTSC_NORMAL_PAR_X) "/" G_STRINGIFY (NTSC_NORMAL_PAR_Y) ","
        G_STRINGIFY (NTSC_WIDE_PAR_X) "/" G_STRINGIFY (NTSC_WIDE_PAR_Y) "},"
        "framerate = (double) [ 1.0, 60.0 ]")
    );

static GstStaticPadTemplate audio_src_temp = GST_STATIC_PAD_TEMPLATE ("audio",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("audio/x-raw-int, "
        "depth = (int) 16, "
        "width = (int) 16, "
        "signed = (boolean) TRUE, "
        "channels = (int) {2, 4}, "
        "endianness = (int) " G_STRINGIFY (G_LITTLE_ENDIAN) ", "
        "rate = (int) { 32000, 44100, 48000 }")
    );

#define GST_TYPE_DVDEC_QUALITY (gst_dvdec_quality_get_type())
GType
gst_dvdec_quality_get_type (void)
{
  static GType qtype = 0;

  if (qtype == 0) {
    static const GEnumValue values[] = {
      {0, "DV_QUALITY_FASTEST", "Fastest decoding, low-quality mono"},
      {1, "DV_QUALITY_AC_1", "Mono decoding using the first AC coefficient"},
      {2, "DV_QUALITY_AC_2", "Highest quality mono decoding"},
      {3, "DV_QUALITY_DC|DV_QUALITY_COLOUR", "Fastest colour decoding"},
      {4, "DV_QUALITY_AC_1|DV_QUALITY_COLOUR",
          "Colour, using only the first AC coefficient"},
      {5, "DV_QUALITY_BEST", "Highest quality colour decoding"},
      {0, NULL, NULL},
    };

    qtype = g_enum_register_static ("GstDVDecQualityEnum", values);
  }
  return qtype;
}

/* A number of functon prototypes are given so we can refer to them later. */
static void gst_dvdec_base_init (gpointer g_class);
static void gst_dvdec_class_init (GstDVDecClass * klass);
static void gst_dvdec_init (GstDVDec * dvdec);

static const GstQueryType *gst_dvdec_get_src_query_types (GstPad * pad);
static gboolean gst_dvdec_src_query (GstPad * pad, GstQuery * query);
static const GstQueryType *gst_dvdec_get_sink_query_types (GstPad * pad);
static gboolean gst_dvdec_sink_query (GstPad * pad, GstQuery * query);

#if 0
static const GstFormat *gst_dvdec_get_formats (GstPad * pad);
#endif
static gboolean gst_dvdec_sink_convert (GstPad * pad, GstFormat src_format,
    gint64 src_value, GstFormat * dest_format, gint64 * dest_value);
static gboolean gst_dvdec_src_convert (GstPad * pad, GstFormat src_format,
    gint64 src_value, GstFormat * dest_format, gint64 * dest_value);

static gboolean gst_dvdec_video_setcaps (GstPad * pad, GstCaps * caps);
static GstCaps *gst_dvdec_video_getcaps (GstPad * pad);

#if 0
static const GstEventMask *gst_dvdec_get_event_masks (GstPad * pad);
#endif
static gboolean gst_dvdec_handle_src_event (GstPad * pad, GstEvent * event);
static GstFlowReturn gst_dvdec_flush (GstDVDec * dvdec);
static GstFlowReturn gst_dvdec_chain (GstPad * pad, GstBuffer * buffer);
static gboolean gst_dvdec_handle_sink_event (GstPad * pad, GstEvent * event);

static GstElementStateReturn gst_dvdec_change_state (GstElement * element);

static void gst_dvdec_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_dvdec_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

/* The parent class pointer needs to be kept around for some object
 * operations.
 */
static GstElementClass *parent_class = NULL;

/* This array holds the ids of the signals registered for this object.
 * The array indexes are based on the enum up above.
 */
/*static guint gst_dvdec_signals[LAST_SIGNAL] = { 0 }; */

/* This function is used to register and subsequently return the type
 * identifier for this object class.  On first invocation, it will
 * register the type, providing the name of the class, struct sizes,
 * and pointers to the various functions that define the class.
 */
GType
gst_dvdec_get_type (void)
{
  static GType dvdec_type = 0;

  if (!dvdec_type) {
    static const GTypeInfo dvdec_info = {
      sizeof (GstDVDecClass),
      gst_dvdec_base_init,
      NULL,
      (GClassInitFunc) gst_dvdec_class_init,
      NULL,
      NULL,
      sizeof (GstDVDec),
      0,
      (GInstanceInitFunc) gst_dvdec_init,
    };

    dvdec_type =
        g_type_register_static (GST_TYPE_ELEMENT, "GstDVDec", &dvdec_info, 0);
  }
  return dvdec_type;
}

static void
gst_dvdec_base_init (gpointer g_class)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

  /* The pad templates can be easily generated from the factories above,
   * and then added to the list of padtemplates for the elementfactory.
   * Note that the generated padtemplates are stored in static global
   * variables, for the gst_dvdec_init function to use later on.
   */
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&sink_temp));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&video_src_temp));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&audio_src_temp));

  gst_element_class_set_details (element_class, &dvdec_details);
}

/* In order to create an instance of an object, the class must be
 * initialized by this function.  GObject will take care of running
 * it, based on the pointer to the function provided above.
 */
static void
gst_dvdec_class_init (GstDVDecClass * klass)
{
  /* Class pointers are needed to supply pointers to the private
   * implementations of parent class methods.
   */
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  /* Since the dvdec class contains the parent classes, you can simply
   * cast the pointer to get access to the parent classes.
   */
  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass *) klass;

  gobject_class->set_property = gst_dvdec_set_property;
  gobject_class->get_property = gst_dvdec_get_property;

  /* The parent class is needed for class method overrides. */
  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);

  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_CLAMP_LUMA,
      g_param_spec_boolean ("clamp_luma", "Clamp luma", "Clamp luma",
          FALSE, G_PARAM_READWRITE));
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_CLAMP_CHROMA,
      g_param_spec_boolean ("clamp_chroma", "Clamp chroma", "Clamp chroma",
          FALSE, G_PARAM_READWRITE));
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_QUALITY,
      g_param_spec_enum ("quality", "Quality", "Decoding quality",
          GST_TYPE_DVDEC_QUALITY, DV_DEFAULT_QUALITY, G_PARAM_READWRITE));
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_DECODE_NTH,
      g_param_spec_int ("drop-factor", "Drop Factor", "Only decode Nth frame",
          1, G_MAXINT, DV_DEFAULT_DECODE_NTH, G_PARAM_READWRITE));

  gstelement_class->change_state = gst_dvdec_change_state;

  /* table initialization, only do once */
  dv_init (0, 0);
}

/* This function is responsible for initializing a specific instance of
 * the plugin.
 */
static void
gst_dvdec_init (GstDVDec * dvdec)
{
  gint i;

  dvdec->sinkpad =
      gst_pad_new_from_template (gst_static_pad_template_get (&sink_temp),
      "sink");
  gst_pad_set_chain_function (dvdec->sinkpad, gst_dvdec_chain);
  gst_pad_set_event_function (dvdec->sinkpad, gst_dvdec_handle_sink_event);
  gst_pad_set_query_function (dvdec->sinkpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_sink_query));
  gst_pad_set_query_type_function (dvdec->sinkpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_get_sink_query_types));
#if 0
  gst_pad_set_formats_function (dvdec->sinkpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_get_formats));
#endif
  gst_element_add_pad (GST_ELEMENT (dvdec), dvdec->sinkpad);

  dvdec->videosrcpad =
      gst_pad_new_from_template (gst_static_pad_template_get (&video_src_temp),
      "video");
  gst_pad_set_query_function (dvdec->videosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_src_query));
  gst_pad_set_query_type_function (dvdec->videosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_get_src_query_types));
  gst_pad_set_event_function (dvdec->videosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_handle_src_event));
#if 0
  gst_pad_set_event_mask_function (dvdec->videosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_get_event_masks));
  gst_pad_set_formats_function (dvdec->videosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_get_formats));
#endif
  gst_pad_set_getcaps_function (dvdec->videosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_video_getcaps));
  gst_pad_set_setcaps_function (dvdec->videosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_video_setcaps));
  gst_element_add_pad (GST_ELEMENT (dvdec), dvdec->videosrcpad);

  dvdec->audiosrcpad =
      gst_pad_new_from_template (gst_static_pad_template_get (&audio_src_temp),
      "audio");
  gst_pad_set_query_function (dvdec->audiosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_src_query));
  gst_pad_set_query_type_function (dvdec->audiosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_get_src_query_types));
  gst_pad_set_event_function (dvdec->audiosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_handle_src_event));
#if 0
  gst_pad_set_event_mask_function (dvdec->audiosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_get_event_masks));
  gst_pad_set_formats_function (dvdec->audiosrcpad,
      GST_DEBUG_FUNCPTR (gst_dvdec_get_formats));
#endif

  /* once we set caps, this is the only thing we can do */
  gst_pad_use_fixed_caps (dvdec->audiosrcpad);
  gst_element_add_pad (GST_ELEMENT (dvdec), dvdec->audiosrcpad);

  dvdec->adapter = gst_adapter_new ();

  dvdec->timestamp = 0LL;

  dvdec->start_timestamp = -1LL;
  dvdec->stop_timestamp = -1LL;
  dvdec->need_discont = FALSE;
  dvdec->new_media = FALSE;
  dvdec->framerate = 0;
  dvdec->height = 0;
  dvdec->frequency = 0;
  dvdec->channels = 0;
  dvdec->wide = FALSE;
  dvdec->drop_factor = 1;

  dvdec->clamp_luma = FALSE;
  dvdec->clamp_chroma = FALSE;
  dvdec->quality = DV_DEFAULT_QUALITY;
  dvdec->loop = FALSE;

  for (i = 0; i < 4; i++) {
    dvdec->audio_buffers[i] =
        (gint16 *) g_malloc (DV_AUDIO_MAX_SAMPLES * sizeof (gint16));
  }
}

#if 0
static const GstFormat *
gst_dvdec_get_formats (GstPad * pad)
{
  static const GstFormat src_formats[] = {
    GST_FORMAT_BYTES,
    GST_FORMAT_DEFAULT,
    GST_FORMAT_TIME,
    0
  };
  static const GstFormat sink_formats[] = {
    GST_FORMAT_BYTES,
    GST_FORMAT_TIME,
    GST_FORMAT_DEFAULT,
    0
  };

  return (GST_PAD_IS_SRC (pad) ? src_formats : sink_formats);
}
#endif

static gboolean
gst_dvdec_src_convert (GstPad * pad, GstFormat src_format, gint64 src_value,
    GstFormat * dest_format, gint64 * dest_value)
{
  gboolean res = TRUE;
  GstDVDec *dvdec;

  dvdec = GST_DVDEC (gst_pad_get_parent (pad));
  if (dvdec->frame_len == -1)
    goto error;

  if (dvdec->decoder == NULL)
    goto error;

  if (*dest_format == src_format) {
    *dest_value = src_value;
    goto done;
  }

  switch (src_format) {
    case GST_FORMAT_BYTES:
      switch (*dest_format) {
        case GST_FORMAT_BYTES:
          *dest_value = src_value;
          break;
        case GST_FORMAT_DEFAULT:
        case GST_FORMAT_TIME:
          *dest_format = GST_FORMAT_TIME;
          if (pad == dvdec->videosrcpad)
            *dest_value = src_value * GST_SECOND /
                (720 * dvdec->height * dvdec->bpp * dvdec->framerate /
                GST_SECOND);
          else if (pad == dvdec->audiosrcpad)
            *dest_value = src_value * GST_SECOND /
                (2 * dvdec->frequency * dvdec->channels);
          break;
        default:
          res = FALSE;
      }
      break;
    case GST_FORMAT_TIME:
      switch (*dest_format) {
        case GST_FORMAT_BYTES:
          if (pad == dvdec->videosrcpad)
            *dest_value = src_value * 720 * dvdec->height * dvdec->bpp *
                dvdec->framerate / GST_SECOND;
          else if (pad == dvdec->audiosrcpad)
            *dest_value = 2 * src_value * dvdec->frequency *
                dvdec->channels / GST_SECOND;
          break;
        case GST_FORMAT_TIME:
        case GST_FORMAT_DEFAULT:
          *dest_format = GST_FORMAT_TIME;
          *dest_value = src_value;
          break;
        default:
          res = FALSE;
      }
      break;
    default:
      res = FALSE;
  }

done:
  gst_object_unref (dvdec);

  return res;

error:
  {
    gst_object_unref (dvdec);
    return FALSE;
  }
}

static gboolean
gst_dvdec_sink_convert (GstPad * pad, GstFormat src_format, gint64 src_value,
    GstFormat * dest_format, gint64 * dest_value)
{
  gboolean res = TRUE;
  GstDVDec *dvdec;
  gdouble framerate;

  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  if (dvdec->frame_len <= 0)
    goto error;

  GST_DEBUG ("%d -> %d", src_format, *dest_format);

  if (*dest_format == GST_FORMAT_DEFAULT)
    *dest_format = GST_FORMAT_TIME;

  if (*dest_format == src_format) {
    *dest_value = src_value;
    goto done;
  }

  framerate = (dvdec->PAL ? PAL_FRAMERATE : NTSC_FRAMERATE);

  switch (src_format) {
    case GST_FORMAT_BYTES:
      switch (*dest_format) {
        case GST_FORMAT_TIME:
        {
          guint64 frame;

          /* get frame number */
          frame = src_value / dvdec->frame_len;

          *dest_value = (frame * GST_SECOND) / framerate;
          break;
        }
        default:
          res = FALSE;
      }
      break;
    case GST_FORMAT_TIME:
      switch (*dest_format) {
        case GST_FORMAT_BYTES:
        {
          guint64 frame;

          /* calculate the frame */
          frame = src_value * framerate / GST_SECOND;
          /* calculate the offset */
          *dest_value = frame * dvdec->frame_len;
          break;
        }
        default:
          res = FALSE;
      }
      break;
    default:
      res = FALSE;
  }

done:
  gst_object_unref (dvdec);
  return res;

error:
  {
    gst_object_unref (dvdec);
    return FALSE;
  }
}

static const GstQueryType *
gst_dvdec_get_src_query_types (GstPad * pad)
{
  static const GstQueryType src_query_types[] = {
    GST_QUERY_POSITION,
    GST_QUERY_CONVERT,
    0
  };

  return src_query_types;
}

static gboolean
gst_dvdec_src_query (GstPad * pad, GstQuery * query)
{
  gboolean res = TRUE;
  GstDVDec *dvdec;

  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_POSITION:
    {
      GstFormat format;
      gint64 cur, end;
      GstPad *peer;

      /* get target format */
      gst_query_parse_position (query, &format, NULL, NULL);

      /* change query to perform on peer */
      gst_query_set_position (query, GST_FORMAT_BYTES, -1, -1);

      if ((peer = gst_pad_get_peer (dvdec->sinkpad))) {
        /* ask peer for total length */
        if (!(res = gst_pad_query (peer, query))) {
          gst_object_unref (peer);
          goto error;
        }

        /* get peer total length */
        gst_query_parse_position (query, NULL, NULL, &end);

        /* convert end to requested format */
        if (end != -1) {
          if (!(res = gst_pad_query_convert (dvdec->sinkpad,
                      GST_FORMAT_BYTES, end, &format, &end))) {
            gst_object_unref (peer);
            goto error;
          }
        }
        gst_object_unref (peer);
      } else {
        end = -1;
      }
      /* bring the position to the requested format. */
      if (!(res = gst_pad_query_convert (pad,
                  GST_FORMAT_TIME, dvdec->timestamp, &format, &cur)))
        goto error;

      gst_query_set_position (query, format, cur, end);
      break;
    }
    case GST_QUERY_CONVERT:
    {
      GstFormat src_fmt, dest_fmt;
      gint64 src_val, dest_val;

      gst_query_parse_convert (query, &src_fmt, &src_val, &dest_fmt, &dest_val);
      if (!(res =
              gst_dvdec_src_convert (pad, src_fmt, src_val, &dest_fmt,
                  &dest_val)))
        goto error;
      gst_query_set_convert (query, src_fmt, src_val, dest_fmt, dest_val);
      break;
    }
    default:
      res = FALSE;
      break;
  }
  gst_object_unref (dvdec);

  return res;

error:
  {
    gst_object_unref (dvdec);
    GST_DEBUG ("error handling event");
    return FALSE;
  }
}

static const GstQueryType *
gst_dvdec_get_sink_query_types (GstPad * pad)
{
  static const GstQueryType sink_query_types[] = {
    GST_QUERY_CONVERT,
    0
  };

  return sink_query_types;
}

static gboolean
gst_dvdec_sink_query (GstPad * pad, GstQuery * query)
{
  gboolean res = TRUE;
  GstDVDec *dvdec;

  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_CONVERT:
    {
      GstFormat src_fmt, dest_fmt;
      gint64 src_val, dest_val;

      gst_query_parse_convert (query, &src_fmt, &src_val, &dest_fmt, &dest_val);
      if (!(res =
              gst_dvdec_sink_convert (pad, src_fmt, src_val, &dest_fmt,
                  &dest_val)))
        goto error;
      gst_query_set_convert (query, src_fmt, src_val, dest_fmt, dest_val);
      break;
    }
    default:
      res = FALSE;
      break;
  }
  gst_object_unref (dvdec);

  return res;

error:
  {
    gst_object_unref (dvdec);
    GST_DEBUG ("error handling event");
    return FALSE;
  }
}

static gboolean
gst_dvdec_send_event (GstDVDec * dvdec, GstEvent * event)
{
  gboolean res = FALSE;

  gst_event_ref (event);
  res |= gst_pad_push_event (dvdec->videosrcpad, event);
  res |= gst_pad_push_event (dvdec->audiosrcpad, event);

  return res;
}

static gboolean
gst_dvdec_handle_sink_event (GstPad * pad, GstEvent * event)
{
  GstDVDec *dvdec = GST_DVDEC (gst_pad_get_parent (pad));
  gboolean res = TRUE;

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_FLUSH:
      if (!GST_EVENT_FLUSH_DONE (event)) {
        /* we are not blocking on anything exect the push() calls
         * to the peer which will be unblocked by forwarding the
         * event.*/
        res = gst_dvdec_send_event (dvdec, event);

        /* and wait till streaming stops, not strictly needed as
         * the peer calling us will do the same. */
        GST_STREAM_LOCK (pad);
        GST_STREAM_UNLOCK (pad);
      } else {
        GST_STREAM_LOCK (pad);
        gst_adapter_clear (dvdec->adapter);
        GST_DEBUG ("cleared adapter");
        res = gst_dvdec_send_event (dvdec, event);
        GST_STREAM_UNLOCK (pad);
      }
      break;
    case GST_EVENT_DISCONTINUOUS:
    {
      GST_STREAM_LOCK (pad);
      /* parse byte start and stop positions */
      if (!(res = gst_event_discont_get_value (event,
                  GST_FORMAT_BYTES, &dvdec->start_byte, &dvdec->stop_byte)))
        goto done;

      /* and queue a DISCONT before sending the next set of buffers */
      dvdec->need_discont = TRUE;
    done:
      gst_event_unref (event);
      GST_STREAM_UNLOCK (pad);
      break;
    }
    case GST_EVENT_EOS:
    default:
      GST_STREAM_LOCK (pad);
      /* flush any pending data */
      gst_dvdec_flush (dvdec);
      /* forward event */
      res = gst_dvdec_send_event (dvdec, event);
      /* and clear the adapter */
      gst_adapter_clear (dvdec->adapter);
      GST_STREAM_UNLOCK (pad);
      break;
  }

  gst_object_unref (dvdec);

  return res;
}

static gboolean
gst_dvdec_handle_src_event (GstPad * pad, GstEvent * event)
{
  gboolean res = TRUE;
  GstDVDec *dvdec;

  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_SEEK:
    {
      gint64 start_position, end_position;
      GstFormat format;
      GstEvent *newevent;
      gint64 offset;

      if ((offset = GST_EVENT_SEEK_OFFSET (event)) != -1) {
        /* bring the format to time on srcpad. */
        format = GST_FORMAT_TIME;
        if (!(res = gst_pad_query_convert (pad,
                    GST_EVENT_SEEK_FORMAT (event),
                    offset, &format, &start_position))) {
          /* could not convert seek format to time offset */
          break;
        }
        /* and convert to bytes on sinkpad. */
        format = GST_FORMAT_BYTES;
        if (!(res = gst_pad_query_convert (dvdec->sinkpad,
                    GST_FORMAT_TIME,
                    start_position, &format, &start_position))) {
          /* could not convert time format to bytes offset */
          break;
        }
      } else {
        start_position = -1;
      }

      if ((offset = GST_EVENT_SEEK_ENDOFFSET (event)) != -1) {
        /* bring the format to time on srcpad. */
        format = GST_FORMAT_TIME;
        if (!(res = gst_pad_query_convert (pad,
                    GST_EVENT_SEEK_FORMAT (event),
                    offset, &format, &end_position))) {
          /* could not convert seek format to time offset */
          break;
        }
        /* and convert to bytes on sinkpad. */
        if (!(res = gst_pad_query_convert (dvdec->sinkpad,
                    GST_FORMAT_TIME, end_position, &format, &end_position))) {
          /* could not convert seek format to bytes offset */
          break;
        }
      } else {
        end_position = -1;
      }
      /* now this is the updated seek event on bytes */
      newevent = gst_event_new_segment_seek (
          (GST_EVENT_SEEK_TYPE (event) & ~GST_SEEK_FORMAT_MASK) |
          GST_FORMAT_BYTES, start_position, end_position);

      res = gst_pad_push_event (dvdec->sinkpad, newevent);
      break;
    }
    default:
      res = FALSE;
      break;
  }
  gst_event_unref (event);

  gst_object_unref (dvdec);

  return res;
}

static GstCaps *
gst_dvdec_video_getcaps (GstPad * pad)
{
  GstDVDec *dvdec;
  GstCaps *caps;
  GstPadTemplate *src_pad_template;

  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  src_pad_template = gst_static_pad_template_get (&video_src_temp);
  caps = gst_caps_copy (gst_pad_template_get_caps (src_pad_template));

  if (dvdec->found_header) {
    int i;
    gint par_x, par_y;

    if (dvdec->PAL) {
      if (dvdec->wide) {
        par_x = PAL_WIDE_PAR_X;
        par_y = PAL_WIDE_PAR_Y;
      } else {
        par_x = PAL_NORMAL_PAR_X;
        par_y = PAL_NORMAL_PAR_Y;
      }
    } else {
      if (dvdec->wide) {
        par_x = NTSC_WIDE_PAR_X;
        par_y = NTSC_WIDE_PAR_Y;
      } else {
        par_x = NTSC_NORMAL_PAR_X;
        par_y = NTSC_NORMAL_PAR_Y;
      }
    }
    /* set the height */
    for (i = 0; i < gst_caps_get_size (caps); i++) {
      GstStructure *structure = gst_caps_get_structure (caps, i);

      gst_structure_set (structure,
          "height", G_TYPE_INT, dvdec->height,
          "framerate", G_TYPE_DOUBLE, dvdec->framerate / dvdec->drop_factor,
          "pixel-aspect-ratio", GST_TYPE_FRACTION, par_x, par_y, NULL);
    }
  }

  gst_object_unref (dvdec);

  return caps;
}

static gboolean
gst_dvdec_video_setcaps (GstPad * pad, GstCaps * caps)
{
  GstDVDec *dvdec;
  GstStructure *structure;
  gint height;
  gdouble framerate;

  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  structure = gst_caps_get_structure (caps, 0);

  if (!gst_structure_get_int (structure, "height", &height) ||
      !gst_structure_get_double (structure, "framerate", &framerate))
    goto not_supported;

  /* allow a margin of error for the framerate caused by float rounding errors */
  if ((height != dvdec->height) ||
      (fabs (framerate - (dvdec->framerate / dvdec->drop_factor)) > 0.00000001))
    goto not_supported;

  if (strcmp (gst_structure_get_name (structure), "video/x-raw-rgb") == 0) {
    gint bpp;

    GST_DEBUG ("got rgb format");

    gst_structure_get_int (structure, "bpp", &bpp);
    if (bpp == 24) {
      dvdec->space = e_dv_color_rgb;
      dvdec->bpp = 3;
      GST_DEBUG ("configured rgb24");
    } else {
      dvdec->space = e_dv_color_bgr0;
      dvdec->bpp = 4;
      GST_DEBUG ("configured bgr32");
    }
  } else {
    guint32 fourcc;

    if (!gst_structure_get_fourcc (structure, "format", &fourcc))
      goto not_supported;

    if (fourcc != GST_STR_FOURCC ("YUY2"))
      goto not_supported;

    dvdec->space = e_dv_color_yuv;
    dvdec->bpp = 2;
    GST_DEBUG ("configured YUY2");
  }

  gst_object_unref (dvdec);

  return TRUE;

not_supported:
  {
    GST_DEBUG ("unsupported format");
    gst_object_unref (dvdec);
    return FALSE;
  }
}

static GstFlowReturn
gst_dvdec_decode_audio (GstDVDec * dvdec, const guint8 * data)
{
  gint num_samples;
  gint frequency, channels;
  GstFlowReturn ret;

  frequency = dv_get_frequency (dvdec->decoder);
  channels = dv_get_num_channels (dvdec->decoder);

  /* check if format changed */
  if ((frequency != dvdec->frequency) || (channels != dvdec->channels)) {
    GstCaps *caps;

    dvdec->frequency = frequency;
    dvdec->channels = channels;

    /* and set new caps */
    caps = gst_caps_new_simple ("audio/x-raw-int",
        "rate", G_TYPE_INT, frequency,
        "depth", G_TYPE_INT, 16,
        "width", G_TYPE_INT, 16,
        "signed", G_TYPE_BOOLEAN, TRUE,
        "channels", G_TYPE_INT, channels,
        "endianness", G_TYPE_INT, G_LITTLE_ENDIAN, NULL);
    gst_pad_set_caps (dvdec->audiosrcpad, caps);
    gst_caps_unref (caps);
  }

  dv_decode_full_audio (dvdec->decoder, data, dvdec->audio_buffers);

  if ((num_samples = dv_get_num_samples (dvdec->decoder)) > 0) {
    gint16 *a_ptr;
    gint i, j;
    GstBuffer *outbuf;

    outbuf = gst_buffer_new_and_alloc (num_samples *
        sizeof (gint16) * dvdec->channels);

    a_ptr = (gint16 *) GST_BUFFER_DATA (outbuf);

    for (i = 0; i < num_samples; i++) {
      for (j = 0; j < dvdec->channels; j++) {
        *(a_ptr++) = dvdec->audio_buffers[j][i];
      }
    }

    GST_DEBUG ("pushing audio %" GST_TIME_FORMAT,
        GST_TIME_ARGS (dvdec->timestamp));

    GST_BUFFER_TIMESTAMP (outbuf) = dvdec->timestamp;
    GST_BUFFER_DURATION (outbuf) = dvdec->duration;
    GST_BUFFER_OFFSET (outbuf) = dvdec->audio_offset;
    dvdec->audio_offset += num_samples;
    GST_BUFFER_OFFSET_END (outbuf) = dvdec->audio_offset;

    gst_buffer_set_caps (outbuf, GST_PAD_CAPS (dvdec->audiosrcpad));

    ret = gst_pad_push (dvdec->audiosrcpad, outbuf);
  } else {
    /* no samples */
    ret = GST_FLOW_OK;
  }

  return ret;
}

static GstFlowReturn
gst_dvdec_decode_video (GstDVDec * dvdec, const guint8 * data)
{
  guint8 *outframe;
  guint8 *outframe_ptrs[3];
  gint outframe_pitches[3];
  gdouble framerate;
  gint height;
  gboolean wide;
  GstBuffer *outbuf;
  GstFlowReturn ret = GST_FLOW_OK;

  /* get params */
  framerate = (dvdec->PAL ? PAL_FRAMERATE : NTSC_FRAMERATE);
  height = (dvdec->PAL ? PAL_HEIGHT : NTSC_HEIGHT);
  wide = dv_format_wide (dvdec->decoder);

  /* see if anything changed */
  if ((dvdec->framerate != framerate) || (dvdec->height != height)
      || dvdec->wide != wide) {
    GstCaps *caps;
    gboolean setcaps_ret;
    gint par_x, par_y;

    dvdec->framerate = framerate;
    dvdec->height = height;
    dvdec->wide = wide;

    if (dvdec->PAL) {
      if (wide) {
        par_x = PAL_WIDE_PAR_X;
        par_y = PAL_WIDE_PAR_Y;
      } else {
        par_x = PAL_NORMAL_PAR_X;
        par_y = PAL_NORMAL_PAR_Y;
      }
    } else {
      if (wide) {
        par_x = NTSC_WIDE_PAR_X;
        par_y = NTSC_WIDE_PAR_Y;
      } else {
        par_x = NTSC_NORMAL_PAR_X;
        par_y = NTSC_NORMAL_PAR_Y;
      }
    }

    /* and set new caps, this will be used as suggestion in alloc
     * function. */
    caps = gst_caps_new_simple ("video/x-raw-yuv",
        "format", GST_TYPE_FOURCC, GST_STR_FOURCC ("YUY2"),
        "width", G_TYPE_INT, 720,
        "height", G_TYPE_INT, height,
        "framerate", G_TYPE_DOUBLE, framerate / dvdec->drop_factor,
        "pixel-aspect-ratio", GST_TYPE_FRACTION, par_x, par_y, NULL);
    setcaps_ret = gst_pad_set_caps (dvdec->videosrcpad, caps);
    gst_caps_unref (caps);
    g_return_val_if_fail (setcaps_ret == TRUE, GST_FLOW_UNEXPECTED);
  }


  /* check if we can skip this frame */
  dvdec->framecount++;
  if (dvdec->framecount < dvdec->drop_factor)
    goto skip;
  dvdec->framecount = 0;

  ret =
      gst_pad_alloc_buffer (dvdec->videosrcpad, 0, (720 * height) * dvdec->bpp,
      GST_PAD_CAPS (dvdec->videosrcpad), &outbuf);
  if (ret != GST_FLOW_OK)
    goto no_buffer;

  outframe = GST_BUFFER_DATA (outbuf);

  outframe_ptrs[0] = outframe;
  outframe_pitches[0] = 720 * dvdec->bpp;

  /* the rest only matters for YUY2 */
  if (dvdec->bpp < 3) {
    outframe_ptrs[1] = outframe_ptrs[0] + 720 * height;
    outframe_ptrs[2] = outframe_ptrs[1] + 360 * height;

    outframe_pitches[1] = height / 2;
    outframe_pitches[2] = outframe_pitches[1];
  }

  dv_decode_full_frame (dvdec->decoder, data,
      dvdec->space, outframe_ptrs, outframe_pitches);

  GST_DEBUG ("pushing video %" GST_TIME_FORMAT,
      GST_TIME_ARGS (dvdec->timestamp));

  GST_BUFFER_TIMESTAMP (outbuf) = dvdec->timestamp;
  GST_BUFFER_OFFSET (outbuf) = dvdec->video_offset;
  GST_BUFFER_OFFSET_END (outbuf) = dvdec->video_offset + 1;
  GST_BUFFER_DURATION (outbuf) = dvdec->duration * dvdec->drop_factor;

  ret = gst_pad_push (dvdec->videosrcpad, outbuf);

skip:
  dvdec->video_offset++;

  return ret;

  /* ERRORS */
no_buffer:
  {
    return ret;
  }
}

static GstFlowReturn
gst_dvdec_decode_frame (GstDVDec * dvdec, const guint8 * data)
{
  GstClockTime next_ts;
  gdouble framerate;
  GstFlowReturn aret, vret, ret;

  if (dvdec->need_discont) {
    GstEvent *event;
    GstFormat format;
    gboolean res;

    /* convert to time and store as start/end_timestamp */
    format = GST_FORMAT_TIME;
    if (!(res = gst_pad_query_convert (dvdec->sinkpad,
                GST_FORMAT_BYTES,
                dvdec->start_byte, &format, &dvdec->start_timestamp))) {
      goto discont_error;
    }

    dvdec->timestamp = dvdec->start_timestamp;

    format = GST_FORMAT_TIME;
    if (!(res = gst_pad_query_convert (dvdec->sinkpad,
                GST_FORMAT_BYTES,
                dvdec->stop_byte, &format, &dvdec->stop_timestamp))) {
      goto discont_error;
    }

    event = gst_event_new_discontinuous (1.0, GST_FORMAT_TIME,
        dvdec->start_timestamp, dvdec->stop_timestamp, NULL);
    gst_dvdec_send_event (dvdec, event);

    dvdec->need_discont = FALSE;
  }

  framerate = (dvdec->PAL ? PAL_FRAMERATE : NTSC_FRAMERATE);

  next_ts = dvdec->timestamp + GST_SECOND / framerate;
  dvdec->duration = next_ts - dvdec->timestamp;

  dv_parse_packs (dvdec->decoder, data);
  if (dv_is_new_recording (dvdec->decoder, data))
    dvdec->new_media = TRUE;

  aret = ret = gst_dvdec_decode_audio (dvdec, data);
  if (ret != GST_FLOW_OK && ret != GST_FLOW_NOT_LINKED)
    goto done;

  vret = ret = gst_dvdec_decode_video (dvdec, data);
  if (ret != GST_FLOW_OK && ret != GST_FLOW_NOT_LINKED)
    goto done;

  if (aret == GST_FLOW_NOT_LINKED && vret == GST_FLOW_NOT_LINKED) {
    ret = GST_FLOW_NOT_LINKED;
    goto done;
  }

  ret = GST_FLOW_OK;
  dvdec->timestamp = next_ts;

done:
  return ret;

discont_error:
  {
    GST_DEBUG ("error generating discont event");
    return GST_FLOW_ERROR;
  }
}

/* flush any remaining data in the adapter */
static GstFlowReturn
gst_dvdec_flush (GstDVDec * dvdec)
{
  GstFlowReturn ret = GST_FLOW_OK;

  while (gst_adapter_available (dvdec->adapter) >= dvdec->frame_len) {
    const guint8 *data;
    gint length;

    /* get the accumulated bytes */
    data = gst_adapter_peek (dvdec->adapter, dvdec->frame_len);

    /* parse header to know the length and other params */
    if (dv_parse_header (dvdec->decoder, data) < 0)
      goto parse_header_error;

    dvdec->found_header = TRUE;

    /* after parsing the header we know the length of the data */
    dvdec->PAL = dv_system_50_fields (dvdec->decoder);
    length = dvdec->frame_len = (dvdec->PAL ? PAL_BUFFER : NTSC_BUFFER);

    /* if we still have enough for a frame, start decoding */
    if (gst_adapter_available (dvdec->adapter) >= length) {

      data = gst_adapter_peek (dvdec->adapter, length);

      /* and decode the data */
      ret = gst_dvdec_decode_frame (dvdec, data);

      gst_adapter_flush (dvdec->adapter, length);

      if (ret != GST_FLOW_OK)
        goto done;
    }
  }
done:
  return ret;

  /* ERRORS */
parse_header_error:
  {
    GST_ELEMENT_ERROR (dvdec, STREAM, DECODE,
        ("Error parsing DV header"), ("Error parsing DV header"));
    gst_object_unref (dvdec);

    return GST_FLOW_ERROR;
  }
}

/* streaming operation: 
 *
 * accumulate data until we have a frame, then decode. 
 */
static GstFlowReturn
gst_dvdec_chain (GstPad * pad, GstBuffer * buffer)
{
  GstDVDec *dvdec;
  GstFlowReturn ret;

  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  gst_adapter_push (dvdec->adapter, buffer);

  /* Apparently dv_parse_header can read from the body of the frame
   * too, so it needs more than header_size bytes. Wacky!
   */
  if (dvdec->frame_len == -1) {
    /* if we don't know the length of a frame, we assume it is
     * the NTSC_BUFFER length, as this is enough to figure out 
     * if this is PAL or NTSC */
    dvdec->frame_len = NTSC_BUFFER;
  }

  /* and try to flush pending frames */
  ret = gst_dvdec_flush (dvdec);

  return ret;
}

static GstElementStateReturn
gst_dvdec_change_state (GstElement * element)
{
  GstDVDec *dvdec = GST_DVDEC (element);
  GstElementStateReturn ret;
  gint transition;

  transition = GST_STATE_TRANSITION (element);

  switch (transition) {
    case GST_STATE_NULL_TO_READY:
      break;
    case GST_STATE_READY_TO_PAUSED:
      dvdec->decoder =
          dv_decoder_new (0, dvdec->clamp_luma, dvdec->clamp_chroma);
      dvdec->decoder->quality = qualities[dvdec->quality];
      dvdec->audio_offset = 0;
      dvdec->video_offset = 0;
      dvdec->framecount = 0;
      dvdec->found_header = FALSE;
      dvdec->frame_len = -1;
      /* 
       * Enable this function call when libdv2 0.100 or higher is more
       * common
       */
      /* dv_set_quality (dvdec->decoder, qualities [dvdec->quality]); */
      break;
    case GST_STATE_PAUSED_TO_PLAYING:
      break;
    default:
      break;
  }

  ret = parent_class->change_state (element);

  switch (transition) {
    case GST_STATE_PLAYING_TO_PAUSED:
      break;
    case GST_STATE_PAUSED_TO_READY:
      gst_adapter_clear (dvdec->adapter);
      dv_decoder_free (dvdec->decoder);
      dvdec->decoder = NULL;
      break;
    case GST_STATE_READY_TO_NULL:
      break;
    default:
      break;
  }
  return ret;
}

static void
gst_dvdec_set_property (GObject * object, guint prop_id, const GValue * value,
    GParamSpec * pspec)
{
  GstDVDec *dvdec;

  /* Get a pointer of the right type. */
  dvdec = GST_DVDEC (object);

  /* Check the argument id to see which argument we're setting. */
  switch (prop_id) {
    case ARG_CLAMP_LUMA:
      dvdec->clamp_luma = g_value_get_boolean (value);
      break;
    case ARG_CLAMP_CHROMA:
      dvdec->clamp_chroma = g_value_get_boolean (value);
      break;
    case ARG_QUALITY:
      dvdec->quality = g_value_get_enum (value);
      if ((dvdec->quality < 0) || (dvdec->quality > 5))
        dvdec->quality = 0;
      break;
    case ARG_DECODE_NTH:
      dvdec->drop_factor = g_value_get_int (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

/* The set function is simply the inverse of the get fuction. */
static void
gst_dvdec_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstDVDec *dvdec;

  dvdec = GST_DVDEC (object);

  switch (prop_id) {
    case ARG_CLAMP_LUMA:
      g_value_set_boolean (value, dvdec->clamp_luma);
      break;
    case ARG_CLAMP_CHROMA:
      g_value_set_boolean (value, dvdec->clamp_chroma);
      break;
    case ARG_QUALITY:
      g_value_set_enum (value, dvdec->quality);
      break;
    case ARG_DECODE_NTH:
      g_value_set_int (value, dvdec->drop_factor);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

/* This is the entry into the plugin itself.  When the plugin loads,
 * this function is called to register everything that the plugin provides.
 */
static gboolean
plugin_init (GstPlugin * plugin)
{
  if (!gst_element_register (plugin, "dvdec", GST_RANK_PRIMARY,
          gst_dvdec_get_type ()))
    return FALSE;

  return TRUE;
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    "dvdec",
    "Uses libdv to decode DV video (libdv.sourceforge.net)",
    plugin_init, VERSION, "LGPL", GST_PACKAGE, GST_ORIGIN);