gstreamer/ext/dv/gstdvdec.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * 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>

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

#define NTSC_HEIGHT 480
#define NTSC_BUFFER 120000
#define NTSC_FRAMERATE 29.997

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

/* 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>\n"
  "Wim Taymans <wim.taymans@tvd.be>"
);


/* 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
};

/* 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,
  /* FILL ME */
};

/* 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)
    " }, "
    "framerate = (double) { "
      G_STRINGIFY(PAL_FRAMERATE) ", "
      G_STRINGIFY(NTSC_FRAMERATE) 
    " }; "

    "video/x-raw-rgb, "
    "bpp = (int) 32, "
    "depth = (int) 32, "
    "endianness = (int) " G_STRINGIFY(G_BIG_ENDIAN) ", "
    "red_mask =   (int) 0x000000ff, "
    "green_mask = (int) 0x0000ff00, "
    "blue_mask =  (int) 0x00ff0000, "
    "width = (int) 720, "
    "height = (int) { "
    	G_STRINGIFY(NTSC_HEIGHT) ", "
	G_STRINGIFY(PAL_HEIGHT)
    " }, "
    "framerate = (double) { "
        G_STRINGIFY(PAL_FRAMERATE) ", "
	G_STRINGIFY(NTSC_FRAMERATE) 
    " }; "

    "video/x-raw-rgb, "
    "bpp = (int) 24, "
    "depth = (int) 24, "
    "endianness = (int) " G_STRINGIFY(G_BIG_ENDIAN) ", "
    "red_mask =   (int) 0x000000ff, "
    "green_mask = (int) 0x0000ff00, "
    "blue_mask =  (int) 0x00ff0000, "
    "width = (int) 720, "
    "height = (int) { "
    	G_STRINGIFY(NTSC_HEIGHT) ", "
	G_STRINGIFY(PAL_HEIGHT)
    " }, "
    "framerate = (double) { "
        G_STRINGIFY(PAL_FRAMERATE) ", "
        G_STRINGIFY(NTSC_FRAMERATE) 
    " }"
  )
);

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, "
    "endianness = (int) " G_STRINGIFY(G_LITTLE_ENDIAN) ", "
    "rate = (int) [ 4000, 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 GFlagsValue values[] = {
      { DV_QUALITY_COLOR, "DV_QUALITY_COLOR", "Color or monochrome decoding" },
      { DV_QUALITY_AC_1,  "DV_QUALITY_AC_1",  "AC 1 something" },
      { DV_QUALITY_AC_2,  "DV_QUALITY_AC_2",  "AC 2 something" },
      { 0, NULL, NULL }
    };
    qtype = g_flags_register_static ("GstDVDecQualityFlags", 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, GstQueryType type,
                    					 GstFormat *format, gint64 *value);
static const GstFormat* gst_dvdec_get_formats 		(GstPad *pad);
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 GstPadLinkReturn gst_dvdec_video_link (GstPad          *pad,
                                              const GstCaps   *caps);
static GstCaps*   gst_dvdec_video_getcaps   (GstPad       *pad);
       
static const GstEventMask*
			gst_dvdec_get_event_masks 	(GstPad *pad);
static gboolean 	gst_dvdec_handle_src_event 	(GstPad *pad, GstEvent *event);

static void		gst_dvdec_loop			(GstElement *element);

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;

  /* 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_flags ("quality", "Quality", "Decoding quality",
                        GST_TYPE_DVDEC_QUALITY, DV_QUALITY_BEST, G_PARAM_READWRITE));

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

  dvdec->sinkpad = gst_pad_new_from_template (gst_static_pad_template_get (&sink_temp), "sink");
  gst_element_add_pad (GST_ELEMENT (dvdec), dvdec->sinkpad);
  gst_pad_set_query_function (dvdec->sinkpad, NULL);
  gst_pad_set_convert_function (dvdec->sinkpad, GST_DEBUG_FUNCPTR (gst_dvdec_sink_convert));
  gst_pad_set_formats_function (dvdec->sinkpad, GST_DEBUG_FUNCPTR (gst_dvdec_get_formats));

  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));
  gst_pad_set_event_mask_function (dvdec->videosrcpad, GST_DEBUG_FUNCPTR (gst_dvdec_get_event_masks));
  gst_pad_set_convert_function (dvdec->videosrcpad, GST_DEBUG_FUNCPTR (gst_dvdec_src_convert));
  gst_pad_set_formats_function (dvdec->videosrcpad, GST_DEBUG_FUNCPTR (gst_dvdec_get_formats));
  gst_pad_set_getcaps_function (dvdec->videosrcpad, GST_DEBUG_FUNCPTR (gst_dvdec_video_getcaps));
  gst_pad_set_link_function (dvdec->videosrcpad, GST_DEBUG_FUNCPTR (gst_dvdec_video_link));
  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));
  gst_pad_set_event_mask_function (dvdec->audiosrcpad, GST_DEBUG_FUNCPTR (gst_dvdec_get_event_masks));
  gst_pad_set_convert_function (dvdec->audiosrcpad, GST_DEBUG_FUNCPTR (gst_dvdec_src_convert));
  gst_pad_set_formats_function (dvdec->audiosrcpad, GST_DEBUG_FUNCPTR (gst_dvdec_get_formats));
  gst_pad_use_explicit_caps (dvdec->audiosrcpad);
  gst_element_add_pad (GST_ELEMENT(dvdec), dvdec->audiosrcpad);

  gst_element_set_loop_function (GST_ELEMENT (dvdec), gst_dvdec_loop);

  dvdec->length = 0;
  dvdec->next_ts = 0LL;
  dvdec->end_position = -1LL;
  dvdec->need_discont = FALSE;
  dvdec->framerate = 0;
  dvdec->height = 0;
  dvdec->frequency = 0;
  dvdec->channels = 0;
  
  dvdec->clamp_luma = FALSE;
  dvdec->clamp_chroma = FALSE;
  dvdec->quality = DV_QUALITY_BEST;
  dvdec->loop = FALSE;
  
  for (i = 0; i <4; i++) {
    dvdec->audio_buffers[i] = (gint16 *)g_malloc (DV_AUDIO_MAX_SAMPLES * sizeof (gint16));
  }
}

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,
    0
  };
	     
  return (GST_PAD_IS_SRC (pad) ? src_formats : sink_formats);
} 

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;
  gint scale = 1;
        
  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  if (dvdec->length == 0)
    return FALSE;

  if (dvdec->decoder == NULL)
    return FALSE;

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

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;
        
  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  if (dvdec->length == 0)
    return FALSE;

  switch (src_format) {
    case GST_FORMAT_BYTES:
      switch (*dest_format) {
        case GST_FORMAT_TIME:
	{
          guint64 frame;
	  /* get frame number */
          frame = src_value / dvdec->length;

          *dest_value = (frame * GST_SECOND) / dvdec->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 * dvdec->framerate / GST_SECOND;
          /* calculate the offset */
          *dest_value = frame * dvdec->length;
          break;
	}
        default:
          res = FALSE;
      }
      break;
    default:
      res = FALSE;
  }
  return res;
}

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

static gboolean
gst_dvdec_src_query (GstPad *pad, GstQueryType type,
                     GstFormat *format, gint64 *value)
{
  gboolean res = TRUE;
  GstDVDec *dvdec;

  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  switch (type) {
    case GST_QUERY_TOTAL:
      switch (*format) {
        default:
	{
          guint64 len;
	  GstFormat tmp_format;

	  len = gst_bytestream_length (dvdec->bs);
	  tmp_format = GST_FORMAT_TIME;
	  if (len == -1 || !gst_pad_convert (dvdec->sinkpad, 
				             GST_FORMAT_BYTES, 
					     len, 
					     &tmp_format, value)) 
	  {
	    return FALSE;
	  }
	  if (!gst_pad_convert (pad, GST_FORMAT_TIME, *value, format, value)) {
	    return FALSE;
	  }
          break;
	}
      }
      break;
    case GST_QUERY_POSITION:
      switch (*format) {
        default:
	  res = gst_pad_convert (pad, GST_FORMAT_TIME, dvdec->next_ts, format, value);
          break;
      }
      break;
    default:
      res = FALSE;
      break;
  }
  return res;
} 

static const GstEventMask*
gst_dvdec_get_event_masks (GstPad *pad)
{ 
  static const GstEventMask src_event_masks[] = {
    { GST_EVENT_SEEK, GST_SEEK_METHOD_SET |
                      GST_SEEK_FLAG_FLUSH },
    { 0, }
  };
  static const GstEventMask sink_event_masks[] = {
    { GST_EVENT_EOS, 0 },
    { GST_EVENT_DISCONTINUOUS, 0 },
    { GST_EVENT_FLUSH, 0 },
    { 0, }
  };

  return (GST_PAD_IS_SRC (pad) ? src_event_masks : sink_event_masks);
} 

static gboolean
gst_dvdec_handle_sink_event (GstDVDec *dvdec)
{
  guint32 remaining;
  GstEvent *event;
  GstEventType type;
	        
  gst_bytestream_get_status (dvdec->bs, &remaining, &event);
		  
  type = event? GST_EVENT_TYPE (event) : GST_EVENT_UNKNOWN;
		      
  switch (type) {
    case GST_EVENT_FLUSH:
      break;
    case GST_EVENT_DISCONTINUOUS:
    {
      gint i;
      gboolean found = FALSE;
      GstFormat format;

      format = GST_FORMAT_TIME;
      /* try to get a timestamp from the discont formats */
      for (i = 0; i < GST_EVENT_DISCONT_OFFSET_LEN(event); i++) {
	if (gst_pad_convert (dvdec->sinkpad, 
			     GST_EVENT_DISCONT_OFFSET(event,i).format, 
			     GST_EVENT_DISCONT_OFFSET(event,i).value,
			     &format, &dvdec->next_ts)) 
	{
          found = TRUE;
	  break;
	}
      }
      /* assume 0 then */
      if (!found) {
	dvdec->next_ts = 0LL;
      }
      dvdec->need_discont = TRUE;
      break;
    }
    default:
      return gst_pad_event_default (dvdec->sinkpad, event);
      break;
  }
  gst_event_unref (event);
  return TRUE;
}

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_SEGMENT:
    {
      gint64 position;
      GstFormat format;

      /* first bring the format to time */
      format = GST_FORMAT_TIME;
      if (!gst_pad_convert (pad, 
			    GST_EVENT_SEEK_FORMAT (event), 
			    GST_EVENT_SEEK_ENDOFFSET (event),
		            &format, &position)) 
      {
        /* could not convert seek format to time offset */
	res = FALSE;
	break;
      }

      dvdec->end_position = position;
      dvdec->loop = GST_EVENT_SEEK_TYPE (event) & GST_SEEK_FLAG_SEGMENT_LOOP;
    }
    case GST_EVENT_SEEK:
    {
      gint64 position;
      GstFormat format;

      /* first bring the format to time */
      format = GST_FORMAT_TIME;
      if (!gst_pad_convert (pad, 
			    GST_EVENT_SEEK_FORMAT (event), 
			    GST_EVENT_SEEK_OFFSET (event),
		            &format, &position)) 
      {
        /* could not convert seek format to time offset */
        res = FALSE;
	break;
      }
      dvdec->next_ts = position;
      /* then try to figure out the byteoffset for this time */
      format = GST_FORMAT_BYTES;
      if (!gst_pad_convert (dvdec->sinkpad, GST_FORMAT_TIME, position,
		        &format, &position)) 
      {
	/* could not convert seek format to byte offset */
	res = FALSE;
	break;
      }
      /* seek to offset */
      if (!gst_bytestream_seek (dvdec->bs, position, GST_SEEK_METHOD_SET)) {
	res = FALSE;
      }
      if (GST_EVENT_TYPE (event) != GST_EVENT_SEEK_SEGMENT)
        dvdec->end_position = -1;
      break;
    }
    default:
      res = FALSE;
      break;
  }
  gst_event_unref (event);
  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;
    
    /* 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, NULL
    	      );
    }
  }
  
  return caps;
}

static GstPadLinkReturn 
gst_dvdec_video_link (GstPad *pad, const GstCaps *caps)
{
  GstDVDec *dvdec;
  GstStructure *structure;
  guint32 fourcc;
  gint height;
  gdouble framerate;
  
  dvdec = GST_DVDEC (gst_pad_get_parent (pad));

  /* if we did not find a header yet, return delayed */
  if (!dvdec->found_header)
  {
    return GST_PAD_LINK_DELAYED;
  }
 
  structure = gst_caps_get_structure (caps, 0);
  
  /* it worked, try to find what it was again */
  if (!gst_structure_get_fourcc (structure, "format", &fourcc) ||
      !gst_structure_get_int (structure, "height", &height) ||
      !gst_structure_get_double (structure, "framerate", &framerate))
    return GST_PAD_LINK_REFUSED;
  
  if ((height != dvdec->height) || (framerate != dvdec->framerate))
    return GST_PAD_LINK_REFUSED;
    
  if (fourcc == GST_STR_FOURCC ("RGB ")) {
    gint bpp;
  
    gst_structure_get_int (structure, "bpp", &bpp);
    if (bpp == 24) {
      dvdec->space = e_dv_color_rgb;
      dvdec->bpp = 3;
    }
    else {
      dvdec->space = e_dv_color_bgr0;
      dvdec->bpp = 4;
    }
  }
  else {
    dvdec->space = e_dv_color_yuv;
    dvdec->bpp = 2;
  }
  
  return GST_PAD_LINK_OK;
}

static void
gst_dvdec_push (GstDVDec *dvdec, GstBuffer *outbuf, GstPad *pad, GstClockTime ts)
{   
  GST_BUFFER_TIMESTAMP (outbuf) = ts;

  if (dvdec->need_discont) {
    GstEvent *discont;

    discont = gst_event_new_discontinuous (FALSE, GST_FORMAT_TIME, ts, NULL);
    gst_pad_push (pad, GST_DATA (discont));
  }

  gst_pad_push (pad, GST_DATA (outbuf));

  if ((dvdec->end_position != -1) &&
      (dvdec->next_ts >= dvdec->end_position)) {
    if (dvdec->loop) 
      gst_pad_push (pad, GST_DATA(gst_event_new (GST_EVENT_SEGMENT_DONE)));
    else
      gst_pad_push (pad, GST_DATA(gst_event_new (GST_EVENT_EOS)));
  }
}

static void
gst_dvdec_loop (GstElement *element)
{   
  GstDVDec *dvdec;
  GstBuffer *buf, *outbuf;
  guint8 *inframe;
  gint height;
  guint32 length, got_bytes;
  GstFormat format;
  guint64 ts;
  gdouble fps;

  dvdec = GST_DVDEC (element);

  /* first read enough bytes to parse the header */
  got_bytes = gst_bytestream_peek_bytes (dvdec->bs, &inframe, header_size);
  if (got_bytes < header_size) {
    gst_dvdec_handle_sink_event (dvdec);
    return;
  }
  if (dv_parse_header (dvdec->decoder, inframe) < 0)
  {
    GST_ELEMENT_ERROR (dvdec, STREAM, DECODE, (NULL), (NULL));
    return;
  }
  
  /* after parsing the header we know the length of the data */
  dvdec->PAL = dv_system_50_fields (dvdec->decoder);
  dvdec->found_header = TRUE;
  
  fps = (dvdec->PAL ? PAL_FRAMERATE : NTSC_FRAMERATE);
  height = (dvdec->PAL ? PAL_HEIGHT : NTSC_HEIGHT);
  length = (dvdec->PAL ? PAL_BUFFER : NTSC_BUFFER);

  if ((dvdec->framerate != fps) ||
      (dvdec->height != height))
  {
    dvdec->height = height;
    dvdec->framerate = fps;
    
    if (GST_PAD_LINK_FAILED (gst_pad_renegotiate (dvdec->videosrcpad)))
    {
      GST_ELEMENT_ERROR (dvdec, CORE, NEGOTIATION, (NULL), (NULL));
      return;
    }
  }
  
  if (length != dvdec->length) {
    dvdec->length = length;
    gst_bytestream_size_hint (dvdec->bs, length);
  }

  /* then read the read data */
  got_bytes = gst_bytestream_read (dvdec->bs, &buf, length);
  if (got_bytes < length) {
    gst_dvdec_handle_sink_event (dvdec);
    return;
  }

  format = GST_FORMAT_TIME;
  gst_pad_query (dvdec->videosrcpad, GST_QUERY_POSITION, &format, &ts);

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

  dv_parse_packs (dvdec->decoder, GST_BUFFER_DATA (buf));

  if (GST_PAD_IS_LINKED (dvdec->audiosrcpad)) {
    gint16 *a_ptr;
    gint i, j;

    dv_decode_full_audio (dvdec->decoder, GST_BUFFER_DATA (buf), dvdec->audio_buffers);

    if ((dvdec->decoder->audio->frequency != dvdec->frequency) ||
        (dvdec->decoder->audio->num_channels != dvdec->channels))
    {
      if (!gst_pad_set_explicit_caps (dvdec->audiosrcpad,
                      gst_caps_new_simple (
                        "audio/x-raw-int", 
                        "rate", G_TYPE_INT, dvdec->decoder->audio->frequency,
                        "depth", G_TYPE_INT,  16,
                        "width", G_TYPE_INT,  16,
                        "signed", G_TYPE_BOOLEAN, TRUE,
                        "channels", G_TYPE_INT, dvdec->decoder->audio->num_channels,
                        "endianness", G_TYPE_INT, G_LITTLE_ENDIAN,
                        NULL
                      )))
      {
        gst_buffer_unref (buf);
        GST_ELEMENT_ERROR (dvdec, CORE, NEGOTIATION, (NULL), (NULL));        
        return;
      }
      
      dvdec->frequency = dvdec->decoder->audio->frequency;
      dvdec->channels = dvdec->decoder->audio->num_channels;
    }
      
    outbuf = gst_buffer_new ();
    GST_BUFFER_SIZE (outbuf) = dvdec->decoder->audio->samples_this_frame * 
                        sizeof (gint16) * dvdec->decoder->audio->num_channels;
    GST_BUFFER_DATA (outbuf) = g_malloc (GST_BUFFER_SIZE (outbuf));
    
    a_ptr = (gint16 *) GST_BUFFER_DATA (outbuf);
    
    for (i = 0; i < dvdec->decoder->audio->samples_this_frame; i++) {
      for (j = 0; j < dvdec->decoder->audio->num_channels; j++) {
        *(a_ptr++) = dvdec->audio_buffers[j][i];
      }
    }
    gst_dvdec_push (dvdec, outbuf, dvdec->audiosrcpad, ts);
  }

  if (GST_PAD_IS_LINKED (dvdec->videosrcpad)) {
    guint8 *outframe;
    guint8 *outframe_ptrs[3];
    gint outframe_pitches[3];

    outbuf = gst_buffer_new_and_alloc ((720 * height) * dvdec->bpp);
    
    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, GST_BUFFER_DATA (buf), 
		          dvdec->space, outframe_ptrs, outframe_pitches);

    gst_dvdec_push (dvdec, outbuf, dvdec->videosrcpad, ts);
  }

  if ((dvdec->end_position != -1) && 
      (dvdec->next_ts >= dvdec->end_position) && 
      !dvdec->loop) {
    gst_element_set_eos (GST_ELEMENT (dvdec));
  }

  if (dvdec->need_discont) {
    dvdec->need_discont = FALSE;
  }

  gst_buffer_unref (buf);
}

static GstElementStateReturn
gst_dvdec_change_state (GstElement *element)
{
  GstDVDec *dvdec = GST_DVDEC (element);
	    
  switch (GST_STATE_TRANSITION (element)) {
    case GST_STATE_NULL_TO_READY:
      break;
    case GST_STATE_READY_TO_PAUSED:
      dvdec->bs = gst_bytestream_new (dvdec->sinkpad);
      dvdec->decoder = dv_decoder_new (0, dvdec->clamp_luma, dvdec->clamp_chroma);
      dvdec->decoder->quality = dvdec->quality;
      break;
    case GST_STATE_PAUSED_TO_PLAYING:
      break;
    case GST_STATE_PLAYING_TO_PAUSED:
      break;
    case GST_STATE_PAUSED_TO_READY:
      dv_decoder_free (dvdec->decoder);
      dvdec->decoder = NULL;
      dvdec->found_header = FALSE;
      gst_bytestream_destroy (dvdec->bs);
      break;
    case GST_STATE_READY_TO_NULL:
      break;
    default:
      break;
  }
	      
  parent_class->change_state (element);
	        
  return GST_STATE_SUCCESS;
}

/* Arguments are part of the Gtk+ object system, and these functions
 * enable the element to respond to various arguments.
 */
static void
gst_dvdec_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
  GstDVDec *dvdec;

  /* It's not null if we got it, but it might not be ours */
  g_return_if_fail(GST_IS_DVDEC(object));

  /* 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_flags (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;

  /* It's not null if we got it, but it might not be ours */
  g_return_if_fail(GST_IS_DVDEC(object));
  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_flags (value, dvdec->quality);
      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_library_load ("gstbytestream"))
    return FALSE;

  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
);