path: root/sys/v4l2/gstv4l2src.c

/* G-Streamer Video4linux2 video-capture plugin
 * Copyright (C) 2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
 *
 * 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 <sys/time.h>
#include "v4l2src_calls.h"
#include "gstv4l2tuner.h"

GST_DEBUG_CATEGORY (v4l2src_debug);
#define GST_CAT_DEFAULT v4l2src_debug

/* elementfactory details */
static GstElementDetails gst_v4l2src_details = {
	"Video (video4linux2) Source",
	"Source/Video",
	"Reads frames (compressed or uncompressed) from a video4linux2 device",
	"Ronald Bultje <rbultje@ronald.bitfreak.net>"
};

/* V4l2Src signals and args */
enum {
	SIGNAL_FRAME_CAPTURE,
	SIGNAL_FRAME_DROP,
	SIGNAL_FRAME_INSERT,
	SIGNAL_FRAME_LOST,
	LAST_SIGNAL
};

/* arguments */
enum {
	ARG_0,
	ARG_NUMBUFS,
	ARG_BUFSIZE,
	ARG_USE_FIXED_FPS
};

guint32 gst_v4l2_formats[] = {
  /* from Linux 2.6.0 videodev2.h */
  V4L2_PIX_FMT_RGB332,   /*  8  RGB-3-3-2     */
  V4L2_PIX_FMT_RGB555,   /* 16  RGB-5-5-5     */
  V4L2_PIX_FMT_RGB565,   /* 16  RGB-5-6-5     */
  V4L2_PIX_FMT_RGB555X,  /* 16  RGB-5-5-5 BE  */
  V4L2_PIX_FMT_RGB565X,  /* 16  RGB-5-6-5 BE  */
  V4L2_PIX_FMT_BGR24,    /* 24  BGR-8-8-8     */
  V4L2_PIX_FMT_RGB24,    /* 24  RGB-8-8-8     */
  V4L2_PIX_FMT_BGR32,    /* 32  BGR-8-8-8-8   */
  V4L2_PIX_FMT_RGB32,    /* 32  RGB-8-8-8-8   */
  V4L2_PIX_FMT_GREY,     /*  8  Greyscale     */
  V4L2_PIX_FMT_YVU410,   /*  9  YVU 4:1:0     */
  V4L2_PIX_FMT_YVU420,   /* 12  YVU 4:2:0     */
  V4L2_PIX_FMT_YUYV,     /* 16  YUV 4:2:2     */
  V4L2_PIX_FMT_UYVY,     /* 16  YUV 4:2:2     */
  V4L2_PIX_FMT_YUV422P,  /* 16  YVU422 planar */
  V4L2_PIX_FMT_YUV411P,  /* 16  YVU411 planar */
  V4L2_PIX_FMT_Y41P,     /* 12  YUV 4:1:1     */
  V4L2_PIX_FMT_NV12,     /* 12  Y/CbCr 4:2:0  */
  V4L2_PIX_FMT_NV21,     /* 12  Y/CrCb 4:2:0  */
  V4L2_PIX_FMT_YUV410,   /*  9  YUV 4:1:0     */
  V4L2_PIX_FMT_YUV420,   /* 12  YUV 4:2:0     */
  V4L2_PIX_FMT_YYUV,     /* 16  YUV 4:2:2     */
  V4L2_PIX_FMT_HI240,    /*  8  8-bit color   */
  V4L2_PIX_FMT_MJPEG,    /* Motion-JPEG       */
  V4L2_PIX_FMT_JPEG,     /* JFIF JPEG         */
  V4L2_PIX_FMT_DV,       /* 1394              */
  V4L2_PIX_FMT_MPEG,     /* MPEG	      */
  V4L2_PIX_FMT_WNVA      /* Winnov hw compres */
};
#define GST_V4L2_FORMAT_COUNT (G_N_ELEMENTS (gst_v4l2_formats))

GST_FORMATS_FUNCTION (GstPad *, gst_v4l2src_get_formats,
		      GST_FORMAT_TIME, GST_FORMAT_DEFAULT);
GST_QUERY_TYPE_FUNCTION (GstPad *, gst_v4l2src_get_query_types,
			 GST_QUERY_POSITION);

/* init functions */
static void			gst_v4l2src_class_init		(gpointer	  g_class,
								 gpointer	  class_data);
static void			gst_v4l2src_base_init		(gpointer	  g_class);
static void			gst_v4l2src_init		(GTypeInstance *  instance,
								 gpointer	  g_class);

/* signal functions */
static void			gst_v4l2src_open		(GstElement      *element,
								 const gchar     *device);
static void			gst_v4l2src_close		(GstElement      *element,
								 const gchar     *device);

/* pad/buffer functions */
static const GstCaps *		gst_v4l2src_get_all_caps	(void);
static GstPadLinkReturn		gst_v4l2src_link		(GstPad          *pad,
								 const GstCaps         *caps);
static GstCaps *		gst_v4l2src_getcaps		(GstPad          *pad);
static GstCaps *                gst_v4l2src_fixate		(GstPad *	  pad, 
								 const GstCaps *  caps);
static GstData *		gst_v4l2src_get			(GstPad          *pad);
static gboolean                 gst_v4l2src_src_convert         (GstPad    *pad,
                                                                 GstFormat  src_format,
                                                                 gint64     src_value,
                                                                 GstFormat *dest_format,
                                                                 gint64    *dest_value);
static gboolean                 gst_v4l2src_src_query           (GstPad      *pad,
                                                                 GstQueryType type, 
                                                                 GstFormat   *format,
                                                                 gint64      *value);

/* get/set params */
static void	gst_v4l2src_set_property	(GObject         *object,
						 guint           prop_id,
						 const GValue    *value,
						 GParamSpec      *pspec);
static void	gst_v4l2src_get_property	(GObject         *object,
						 guint           prop_id,
						 GValue          *value,
						 GParamSpec      *pspec);

/* state handling */
static GstElementStateReturn
		gst_v4l2src_change_state	(GstElement      *element);

/* set_clock function for A/V sync */
static void	gst_v4l2src_set_clock		(GstElement     *element,
						 GstClock       *clock);

static GstElementClass *parent_class = NULL;
static guint gst_v4l2src_signals[LAST_SIGNAL] = { 0 };


GType
gst_v4l2src_get_type (void)
{
  static GType v4l2src_type = 0;

  if (!v4l2src_type) {
    static const GTypeInfo v4l2src_info = {
      sizeof (GstV4l2SrcClass),
      gst_v4l2src_base_init,
      NULL,
      gst_v4l2src_class_init,
      NULL,
      NULL,
      sizeof (GstV4l2Src),
      0,
      gst_v4l2src_init,
      NULL
    };
    v4l2src_type = g_type_register_static(GST_TYPE_V4L2ELEMENT,
	"GstV4l2Src", &v4l2src_info, 0);
    GST_DEBUG_CATEGORY_INIT (v4l2src_debug, "v4l2src", 0, "v4l2src element");
  }
  return v4l2src_type;
}

static void
gst_v4l2src_base_init (gpointer g_class)
{
  GstPadTemplate *template;
  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
  
  gst_element_class_set_details (gstelement_class, &gst_v4l2src_details);

  template = gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
      gst_caps_copy (gst_v4l2src_get_all_caps ()));

  gst_element_class_add_pad_template (gstelement_class, template);
}

static void
gst_v4l2src_class_init (gpointer g_class, gpointer class_data)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (g_class);
  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
  GstV4l2ElementClass *v4l2_class = GST_V4L2ELEMENT_CLASS (g_class);

  parent_class = g_type_class_peek_parent (g_class);

  gobject_class->set_property = gst_v4l2src_set_property;
  gobject_class->get_property = gst_v4l2src_get_property;

  g_object_class_install_property(gobject_class, ARG_NUMBUFS,
	  g_param_spec_int("num_buffers","num_buffers","num_buffers",
			   G_MININT,G_MAXINT,0,G_PARAM_READWRITE));
  g_object_class_install_property(gobject_class, ARG_BUFSIZE,
	  g_param_spec_int("buffer_size","buffer_size","buffer_size",
			   G_MININT,G_MAXINT,0,G_PARAM_READABLE));

  g_object_class_install_property(gobject_class, ARG_USE_FIXED_FPS,
	  g_param_spec_boolean("use_fixed_fps", "Use Fixed FPS",
			       "Drop/Insert frames to reach a certain FPS (TRUE) "
			       "or adapt FPS to suit the number of frabbed frames",
			       TRUE, G_PARAM_READWRITE));

  /* signals */
  gst_v4l2src_signals[SIGNAL_FRAME_CAPTURE] =
	  g_signal_new("frame_capture", G_TYPE_FROM_CLASS (g_class), G_SIGNAL_RUN_LAST,
		       G_STRUCT_OFFSET(GstV4l2SrcClass, frame_capture),
		       NULL, NULL, g_cclosure_marshal_VOID__VOID,
		       G_TYPE_NONE, 0);
  gst_v4l2src_signals[SIGNAL_FRAME_DROP] =
	  g_signal_new("frame_drop", G_TYPE_FROM_CLASS (g_class), G_SIGNAL_RUN_LAST,
		       G_STRUCT_OFFSET(GstV4l2SrcClass, frame_drop),
		       NULL, NULL, g_cclosure_marshal_VOID__VOID,
		       G_TYPE_NONE, 0);
  gst_v4l2src_signals[SIGNAL_FRAME_INSERT] =
	  g_signal_new("frame_insert", G_TYPE_FROM_CLASS (g_class), G_SIGNAL_RUN_LAST,
		       G_STRUCT_OFFSET(GstV4l2SrcClass, frame_insert),
		       NULL, NULL, g_cclosure_marshal_VOID__VOID,
		       G_TYPE_NONE, 0);
  gst_v4l2src_signals[SIGNAL_FRAME_LOST] =
	  g_signal_new("frame_lost", G_TYPE_FROM_CLASS (g_class), G_SIGNAL_RUN_LAST,
		       G_STRUCT_OFFSET(GstV4l2SrcClass, frame_lost),
		       NULL, NULL, g_cclosure_marshal_VOID__INT,
		       G_TYPE_NONE, 1, G_TYPE_INT);

  gstelement_class->change_state = gst_v4l2src_change_state;

  v4l2_class->open = gst_v4l2src_open;
  v4l2_class->close = gst_v4l2src_close;

  gstelement_class->set_clock = gst_v4l2src_set_clock;
}


static void
gst_v4l2src_init (GTypeInstance *instance, gpointer g_class)
{
  GstV4l2Src *v4l2src = GST_V4L2SRC (instance);
  
  GST_FLAG_SET(GST_ELEMENT(v4l2src), GST_ELEMENT_THREAD_SUGGESTED);

  v4l2src->srcpad = gst_pad_new_from_template(
      gst_element_class_get_pad_template (GST_ELEMENT_GET_CLASS (v4l2src), "src"), "src");
  gst_element_add_pad(GST_ELEMENT(v4l2src), v4l2src->srcpad);

  gst_pad_set_get_function(v4l2src->srcpad, gst_v4l2src_get);
  gst_pad_set_link_function(v4l2src->srcpad, gst_v4l2src_link);
  gst_pad_set_getcaps_function (v4l2src->srcpad, gst_v4l2src_getcaps);
  gst_pad_set_fixate_function (v4l2src->srcpad, gst_v4l2src_fixate);
  gst_pad_set_convert_function (v4l2src->srcpad, gst_v4l2src_src_convert);
  gst_pad_set_formats_function (v4l2src->srcpad, gst_v4l2src_get_formats);
  gst_pad_set_query_function (v4l2src->srcpad, gst_v4l2src_src_query);
  gst_pad_set_query_type_function (v4l2src->srcpad, gst_v4l2src_get_query_types);

  v4l2src->breq.count = 0;

  v4l2src->formats = NULL;

  /* no clock */
  v4l2src->clock = NULL;

  /* fps */
  v4l2src->use_fixed_fps = TRUE;
}


static void
gst_v4l2src_open (GstElement  *element,
                  const gchar *device)
{
  gst_v4l2src_fill_format_list (GST_V4L2SRC (element));
}


static void
gst_v4l2src_close (GstElement  *element,
                   const gchar *device)
{
  gst_v4l2src_clear_format_list (GST_V4L2SRC (element));
}


static gfloat
gst_v4l2src_get_fps (GstV4l2Src *v4l2src)
{
	v4l2_std_id norm;
	const GList *item;

	if (!v4l2src->use_fixed_fps &&
	    v4l2src->clock != NULL &&
	    v4l2src->handled > 0) {
		/* try to get time from clock master and calculate fps */
		GstClockTime time = gst_clock_get_time(v4l2src->clock) -
		                      v4l2src->substract_time;
		return v4l2src->handled * GST_SECOND / time;
	}

	/* if that failed ... */
 
	if (!GST_V4L2_IS_OPEN(GST_V4L2ELEMENT(v4l2src)))
		return 0.;

	if (!gst_v4l2_get_norm(GST_V4L2ELEMENT(v4l2src), &norm))
		return 0.;
	for (item = GST_V4L2ELEMENT(v4l2src)->norms;
	     item != NULL; item = item->next) {
		GstV4l2TunerNorm *v4l2norm = item->data;
		if (v4l2norm->index == norm)
			return GST_TUNER_NORM(v4l2norm)->fps;
	}

	return 0.;
}

static gboolean
gst_v4l2src_src_convert (GstPad    *pad,
                         GstFormat  src_format,
                         gint64     src_value,
                         GstFormat *dest_format,
                         gint64    *dest_value)
{
	GstV4l2Src *v4l2src;
	gdouble fps;

	v4l2src = GST_V4L2SRC (gst_pad_get_parent (pad));

	if ((fps = gst_v4l2src_get_fps(v4l2src)) == 0)
		return FALSE;

	switch (src_format) {
		case GST_FORMAT_TIME:
			switch (*dest_format) {
				case GST_FORMAT_DEFAULT:
					*dest_value = src_value * fps / GST_SECOND;
					break;
				default:
					return FALSE;
			}
			break;

		case GST_FORMAT_DEFAULT:
			switch (*dest_format) {
				case GST_FORMAT_TIME:
					*dest_value = src_value * GST_SECOND / fps;
					break;
				default:
					return FALSE;
			}
			break;

		default:
			return FALSE;
	}

	return TRUE;
}

static gboolean
gst_v4l2src_src_query (GstPad      *pad,
                       GstQueryType type, 
                       GstFormat   *format,
                       gint64      *value)
{
  GstV4l2Src *v4l2src = GST_V4L2SRC (gst_pad_get_parent (pad));
  gboolean res = TRUE;
  gdouble fps;

  if ((fps = gst_v4l2src_get_fps(v4l2src)) == 0)
    return FALSE;

  switch (type) {
    case GST_QUERY_POSITION:
      switch (*format) {
        case GST_FORMAT_TIME:
          *value = v4l2src->handled * GST_SECOND / fps;
          break;
        case GST_FORMAT_DEFAULT:
          *value = v4l2src->handled;
          break;
        default:
          res = FALSE;
          break;
      }
      break;
    default:
      res = FALSE;
      break;
  }

  return res;
}

static GstStructure *
gst_v4l2src_v4l2fourcc_to_caps (guint32 fourcc)
{
  GstStructure *structure = NULL;

  switch (fourcc) {
    case V4L2_PIX_FMT_MJPEG: /* Motion-JPEG */
    case V4L2_PIX_FMT_JPEG:  /* JFIF JPEG */
      structure = gst_structure_new ("video/x-jpeg", NULL);
      break;
    case V4L2_PIX_FMT_RGB332:
    case V4L2_PIX_FMT_RGB555:
    case V4L2_PIX_FMT_RGB555X:
    case V4L2_PIX_FMT_RGB565:
    case V4L2_PIX_FMT_RGB565X:
    case V4L2_PIX_FMT_RGB24:
    case V4L2_PIX_FMT_BGR24:
    case V4L2_PIX_FMT_RGB32:
    case V4L2_PIX_FMT_BGR32: {
      guint depth=0, bpp=0;
      gint endianness = 0;
      guint32 r_mask = 0, b_mask = 0, g_mask = 0;

      switch (fourcc) {
	case V4L2_PIX_FMT_RGB332:
	  bpp = depth = 8;
	  endianness = G_BYTE_ORDER; /* 'like, whatever' */
	  r_mask = 0xe0; g_mask = 0x1c; b_mask = 0x03;
	  break;
	case V4L2_PIX_FMT_RGB555:
	case V4L2_PIX_FMT_RGB555X:
	  bpp = 16; depth = 15;
	  endianness = fourcc == V4L2_PIX_FMT_RGB555X ? G_BIG_ENDIAN : G_LITTLE_ENDIAN;
	  r_mask = 0x7c00;
	  g_mask = 0x03e0;
	  b_mask = 0x001f;
	  break;
	case V4L2_PIX_FMT_RGB565:
	case V4L2_PIX_FMT_RGB565X:
	  bpp = depth = 16;
	  endianness = fourcc == V4L2_PIX_FMT_RGB565X ? G_BIG_ENDIAN : G_LITTLE_ENDIAN;
	  r_mask = 0xf800;
	  g_mask = 0x07e0;
	  b_mask = 0x001f;
	case V4L2_PIX_FMT_RGB24:
	  bpp = depth = 24;
	  endianness = G_BIG_ENDIAN;
	  r_mask = 0xff0000;
	  g_mask = 0x00ff00;
	  b_mask = 0x0000ff;
	  break;
	case V4L2_PIX_FMT_BGR24:
	  bpp = depth = 24;
	  endianness = G_BIG_ENDIAN;
	  r_mask = 0x0000ff;
	  g_mask = 0x00ff00;
	  b_mask = 0xff0000;
	  break;
	case V4L2_PIX_FMT_RGB32:
	  bpp = depth = 32;
	  endianness = G_BIG_ENDIAN;
	  r_mask = 0xff000000;
	  g_mask = 0x00ff0000;
	  b_mask = 0x0000ff00;
	  break;
	case V4L2_PIX_FMT_BGR32:
	  bpp = depth = 32;
	  endianness = G_BIG_ENDIAN;
	  r_mask = 0x000000ff;
	  g_mask = 0x0000ff00;
	  b_mask = 0x00ff0000;
	  break;
	default:
	  g_assert_not_reached();
	  break;
      }
      structure = gst_structure_new ("video/x-raw-rgb",
	  "bpp",        G_TYPE_INT, bpp,
	  "depth",      G_TYPE_INT, depth,
	  "red_mask",   G_TYPE_INT, r_mask,
	  "green_mask", G_TYPE_INT, g_mask,
	  "blue_mask",  G_TYPE_INT, b_mask,
	  "endianness", G_TYPE_INT, endianness,
	  NULL);
      break;
    }
    case V4L2_PIX_FMT_GREY:		/*  8  Greyscale     */
    case V4L2_PIX_FMT_YUV422P:		/* 16  YVU422 planar */
    case V4L2_PIX_FMT_YUV411P:		/* 16  YVU411 planar */
    case V4L2_PIX_FMT_NV12:		/* 12  Y/CbCr 4:2:0  */
    case V4L2_PIX_FMT_NV21:		/* 12  Y/CrCb 4:2:0  */
    case V4L2_PIX_FMT_YYUV:		/* 16  YUV 4:2:2     */
    case V4L2_PIX_FMT_HI240:		/*  8  8-bit color   */
      /* FIXME: get correct fourccs here */
      break;
    case V4L2_PIX_FMT_YVU410:
    case V4L2_PIX_FMT_YUV410:
    case V4L2_PIX_FMT_YUV420: /* I420/IYUV */
    case V4L2_PIX_FMT_YUYV:
    case V4L2_PIX_FMT_YVU420:
    case V4L2_PIX_FMT_UYVY:
    case V4L2_PIX_FMT_Y41P: {
      guint32 fcc = 0;

      switch (fourcc) {
	case V4L2_PIX_FMT_YVU410:
	  fcc = GST_MAKE_FOURCC('Y','V','U','9');
	  break;
	case V4L2_PIX_FMT_YUV410:
	  fcc = GST_MAKE_FOURCC('Y','U','V','9');
	  break;
	case V4L2_PIX_FMT_YUV420:
	  fcc = GST_MAKE_FOURCC('I','4','2','0');
	  break;
	case V4L2_PIX_FMT_YUYV:
	  fcc = GST_MAKE_FOURCC('Y','U','Y','2');
	  break;
	case V4L2_PIX_FMT_YVU420:
	  fcc = GST_MAKE_FOURCC('Y','V','1','2');
	  break;
	case V4L2_PIX_FMT_UYVY:
	  fcc = GST_MAKE_FOURCC('U','Y','V','Y');
	  break;
	case V4L2_PIX_FMT_Y41P:
	  fcc = GST_MAKE_FOURCC('Y','4','1','B');
	  break;
	default:
	  g_assert_not_reached();
	  break;
      }
      structure = gst_structure_new ("video/x-raw-yuv",
	  "format", GST_TYPE_FOURCC, fcc,
          NULL);
      break;
    }
    case V4L2_PIX_FMT_DV:
      structure = gst_structure_new ("video/x-dv", "systemstream", G_TYPE_BOOLEAN, TRUE, NULL);
      break;
    case V4L2_PIX_FMT_MPEG:		/* MPEG          */
      /* someone figure out the MPEG format used... */
      break;
    case V4L2_PIX_FMT_WNVA:		/* Winnov hw compres */
      break;
    default:
      GST_DEBUG ("Unknown fourcc 0x%08x " GST_FOURCC_FORMAT,
			  fourcc, GST_FOURCC_ARGS(fourcc));
      break;
  }
#if 0
        gst_caps_set_simple (caps,
            "width", G_TYPE_INT, width,
            "height", G_TYPE_INT, height,
            "framerate", G_TYPE_DOUBLE, fps,
            NULL);
#endif
  return structure;
}

static struct v4l2_fmtdesc *
gst_v4l2src_get_format_from_fourcc (GstV4l2Src *v4l2src, guint32 fourcc)
{ 
  struct v4l2_fmtdesc *fmt;
  GSList *walk;
  
  if (fourcc == 0)
    return NULL;
  
  walk = v4l2src->formats;
  while (walk) {
    fmt = (struct v4l2_fmtdesc *) walk->data;
    if (fmt->pixelformat == fourcc)
      return fmt;
    /* special case for jpeg */
    if ((fmt->pixelformat == V4L2_PIX_FMT_MJPEG && fourcc == V4L2_PIX_FMT_JPEG) ||
	(fmt->pixelformat == V4L2_PIX_FMT_JPEG && fourcc == V4L2_PIX_FMT_MJPEG)) {
      return fmt;
    }
    walk = g_slist_next (walk);
  }

  return NULL;
}

static guint32
gst_v4l2_fourcc_from_structure (GstStructure *structure)
{
  guint32 fourcc = 0;
  const gchar *mimetype = gst_structure_get_name (structure);

  if (!strcmp(mimetype, "video/x-raw-yuv") ||
      !strcmp(mimetype, "video/x-raw-rgb")) {
    if (!strcmp(mimetype, "video/x-raw-rgb"))
      fourcc = GST_MAKE_FOURCC('R','G','B',' ');
    else
      gst_structure_get_fourcc (structure, "format", &fourcc);

    switch (fourcc) {
      case GST_MAKE_FOURCC('I','4','2','0'):
      case GST_MAKE_FOURCC('I','Y','U','V'):
	fourcc = V4L2_PIX_FMT_YUV420;
	break;
      case GST_MAKE_FOURCC('Y','U','Y','2'):
	fourcc = V4L2_PIX_FMT_YUYV;
	break;
      case GST_MAKE_FOURCC('Y','4','1','P'):
	fourcc = V4L2_PIX_FMT_Y41P;
	break;
      case GST_MAKE_FOURCC('U','Y','V','Y'):
	fourcc = V4L2_PIX_FMT_UYVY;
	break;
      case GST_MAKE_FOURCC('Y','V','1','2'):
	fourcc = V4L2_PIX_FMT_YVU420;
	break;
      case GST_MAKE_FOURCC('R','G','B',' '): {
	gint depth, endianness, r_mask;

	gst_structure_get_int (structure, "depth", &depth);
	gst_structure_get_int (structure, "endianness", &endianness);
	gst_structure_get_int (structure, "red_mask", &r_mask);

	switch (depth) {
	  case 8:
	    fourcc = V4L2_PIX_FMT_RGB332;
	    break;
	  case 15:
	    fourcc = (endianness == G_LITTLE_ENDIAN) ?
		V4L2_PIX_FMT_RGB555 :
		V4L2_PIX_FMT_RGB555X;
	    break;
	  case 16:
	    fourcc = (endianness == G_LITTLE_ENDIAN) ?
		V4L2_PIX_FMT_RGB565 :
		V4L2_PIX_FMT_RGB565X;
	    break;
	  case 24:
	    fourcc = (r_mask == 0xFF) ?
		V4L2_PIX_FMT_BGR24 :
		V4L2_PIX_FMT_RGB24;
	    break;
	  case 32:
	    fourcc = (r_mask == 0xFF) ?
		V4L2_PIX_FMT_BGR32 :
		V4L2_PIX_FMT_RGB32;
	    break;
	}
	default:
	  break;
      }
    } 
  } else if (strcmp (mimetype, "video/x-dv") == 0) {
    fourcc = V4L2_PIX_FMT_DV;
  } else if (strcmp (mimetype, "video/x-jpeg") == 0) {
    fourcc = V4L2_PIX_FMT_JPEG;
  }

  return fourcc;
}

static struct v4l2_fmtdesc *
gst_v4l2_caps_to_v4l2fourcc (GstV4l2Src *v4l2src, GstStructure *structure)
{
  return gst_v4l2src_get_format_from_fourcc (v4l2src,
      gst_v4l2_fourcc_from_structure (structure));
}

static const GstCaps *
gst_v4l2src_get_all_caps (void)
{
  static GstCaps *caps = NULL;

  if (caps == NULL) {
    GstStructure *structure;
    guint i;

    caps = gst_caps_new_empty ();
    for (i = 0; i < GST_V4L2_FORMAT_COUNT; i++) {
      structure = gst_v4l2src_v4l2fourcc_to_caps (gst_v4l2_formats[i]);
      if (structure) {
	gst_structure_set (structure,
	    "width", GST_TYPE_INT_RANGE, 1, 4096,
	    "height", GST_TYPE_INT_RANGE, 1, 4096,
	    "framerate", GST_TYPE_DOUBLE_RANGE, (double) 0, G_MAXDOUBLE,
	    NULL);

	gst_caps_append_structure (caps, structure);
      }
    }
  }

  return caps;
}

static GstCaps *
gst_v4l2src_fixate (GstPad *pad, const GstCaps *const_caps)
{
  gint i;
  GstStructure *structure;
  G_GNUC_UNUSED gchar *caps_str;
  gboolean changed = FALSE;
  GstCaps *caps = gst_caps_copy (const_caps);

  caps_str = gst_caps_to_string (caps);
  GST_DEBUG_OBJECT (gst_pad_get_parent (pad), "fixating caps %s", caps_str);
  g_free (caps_str);
  
  for (i = 0; i < gst_caps_get_size (caps); i++) {
    structure = gst_caps_get_structure (caps, i);
    changed |= gst_caps_structure_fixate_field_nearest_int (structure, "width", G_MAXINT);
  }
  if (changed) return caps;

  for (i = 0; i < gst_caps_get_size (caps); i++) {
    structure = gst_caps_get_structure (caps, i);
    changed |= gst_caps_structure_fixate_field_nearest_int (structure, "height", G_MAXINT);
  }
  if (changed) return caps;

  gst_caps_free (caps);
  return NULL;
}

static GstPadLinkReturn
gst_v4l2src_link (GstPad *pad, const GstCaps *caps)
{
  GstV4l2Src *v4l2src;
  GstV4l2Element *v4l2element;
  struct v4l2_fmtdesc *format;
  int w, h;
  GstStructure *structure;

  v4l2src = GST_V4L2SRC(gst_pad_get_parent (pad));
  v4l2element = GST_V4L2ELEMENT(v4l2src);

  structure = gst_caps_get_structure (caps, 0);

  /* clean up if we still haven't cleaned up our previous
   * capture session */
  if (GST_V4L2_IS_ACTIVE(v4l2element)) {
	  if (!gst_v4l2src_capture_deinit(v4l2src))
		  return GST_PAD_LINK_REFUSED;
  } else if (!GST_V4L2_IS_OPEN(v4l2element)) {
	  return GST_PAD_LINK_DELAYED;
  }

  /* we want our own v4l2 type of fourcc codes */
  if (!(format = gst_v4l2_caps_to_v4l2fourcc(v4l2src, structure))) {
	  return GST_PAD_LINK_REFUSED;
  }

  gst_structure_get_int (structure, "width", &w);
  gst_structure_get_int (structure, "height", &h);

  /* we found the pixelformat! - try it out */
  if (gst_v4l2src_set_capture(v4l2src, format, w, h)) {
	  if (gst_v4l2src_capture_init(v4l2src)) {
		  return GST_PAD_LINK_OK;
	  }
  }

  return GST_PAD_LINK_REFUSED;
}


static GstCaps *
gst_v4l2src_getcaps (GstPad  *pad)
{
  GstV4l2Src *v4l2src = GST_V4L2SRC(gst_pad_get_parent (pad));
  GstCaps *caps;
  struct v4l2_fmtdesc *format;
  int min_w, max_w, min_h, max_h;
  GSList *walk;
  GstStructure *structure;

  if (!GST_V4L2_IS_OPEN(GST_V4L2ELEMENT(v4l2src))) {
	  return gst_caps_new_any ();
  }

  /* build our own capslist */
  caps = gst_caps_new_empty();
  walk = v4l2src->formats;
  while (walk) {
    format = (struct v4l2_fmtdesc *) walk->data;
    walk = g_slist_next (walk);

    /* get size delimiters */
    if (!gst_v4l2src_get_size_limits(v4l2src, format,
	&min_w, &max_w, &min_h, &max_h)) {
      continue;
    }

    /* add to list */
    structure = gst_v4l2src_v4l2fourcc_to_caps (format->pixelformat);

    if (structure) {
      gst_structure_set (structure,
	  "width", GST_TYPE_INT_RANGE, min_w, max_w,
	  "height", GST_TYPE_INT_RANGE, min_h, max_h,
	  "framerate", GST_TYPE_DOUBLE_RANGE, (double) 0, G_MAXDOUBLE,
	  NULL);

      gst_caps_append_structure (caps, structure);
    }
  }

  return caps;
}

static GstData*
gst_v4l2src_get (GstPad *pad)
{
  GstV4l2Src *v4l2src;
  GstBuffer *buf;
  gint i, num = -1;
  gdouble fps = 0;

  v4l2src = GST_V4L2SRC (gst_pad_get_parent (pad));

  if (v4l2src->use_fixed_fps &&
      (fps = gst_v4l2src_get_fps(v4l2src)) == 0) {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, SETTINGS, (NULL), ("could not get frame rate for element"));
    return NULL;
  }

  if (v4l2src->need_writes > 0) {
    /* use last frame */
    buf = v4l2src->cached_buffer;
    v4l2src->need_writes--;
  } else {
    GstClockTime time;
    /* grab a frame from the device */
    num = gst_v4l2src_grab_frame(v4l2src);
    if (num == -1)
      return NULL;

    /* to check if v4l2 sets the correct time */
    time = GST_TIMEVAL_TO_TIME(v4l2src->pool->buffers[num].buffer.timestamp);
    if (v4l2src->clock && v4l2src->use_fixed_fps && time != 0) {
      gboolean have_frame = FALSE;

      do {
	/* FIXME: isn't this v4l2 timestamp its own clock?! */
	/* by default, we use the frame once */
	v4l2src->need_writes = 1;

	g_assert (time >= v4l2src->substract_time);
	time -= v4l2src->substract_time;

	/* first check whether we lost any frames according to the device */
	if (v4l2src->last_seq != 0) {
	  if (v4l2src->pool->buffers[num].buffer.sequence - v4l2src->last_seq > 1) {
	    v4l2src->need_writes = v4l2src->pool->buffers[num].buffer.sequence - v4l2src->last_seq;
	    g_signal_emit(G_OBJECT(v4l2src), gst_v4l2src_signals[SIGNAL_FRAME_LOST], 0,
		v4l2src->need_writes - 1);
	  }
	}
	v4l2src->last_seq = v4l2src->pool->buffers[num].buffer.sequence;

	/* decide how often we're going to write the frame - set
	 * v4lmjpegsrc->need_writes to (that-1) and have_frame to TRUE
	 * if we're going to write it - else, just continue.
	 * 
	 * time is generally the system or audio clock. Let's
	 * say that we've written one second of audio, then we want
	 * to have written one second of video too, within the same
	 * timeframe. This means that if time - begin_time = X sec,
	 * we want to have written X*fps frames. If we've written
	 * more - drop, if we've written less - dup... */
	if (v4l2src->handled * (GST_SECOND/fps) - time > 1.5 * (GST_SECOND/fps)) {
	  /* yo dude, we've got too many frames here! Drop! DROP! */
	  v4l2src->need_writes--; /* -= (v4l2src->handled - (time / fps)); */
	  g_signal_emit(G_OBJECT(v4l2src), gst_v4l2src_signals[SIGNAL_FRAME_DROP], 0);
	} else if (v4l2src->handled * (GST_SECOND/fps) - time < -1.5 * (GST_SECOND/fps)) {
	  /* this means we're lagging far behind */
	  v4l2src->need_writes++; /* += ((time / fps) - v4l2src->handled); */
	  g_signal_emit(G_OBJECT(v4l2src), gst_v4l2src_signals[SIGNAL_FRAME_INSERT], 0);
	}

	if (v4l2src->need_writes > 0) {
	  have_frame = TRUE;
	  v4l2src->need_writes--;
	} else {
	  if (!gst_v4l2src_queue_frame(v4l2src, num))
	    return NULL;
	  num = gst_v4l2src_grab_frame(v4l2src);
	  if (num == -1)
	    return NULL;
	}
      } while (!have_frame);
    }

    g_assert (num != -1);
    GST_LOG_OBJECT (v4l2src, "buffer %d needs %d writes", num, v4l2src->need_writes + 1);
    i = v4l2src->pool->buffers[num].buffer.bytesused > 0 ? 
      v4l2src->pool->buffers[num].buffer.bytesused : 
      v4l2src->pool->buffers[num].length;
    /* check if this is the last buffer in the queue. If so do a memcpy to put it back asap
       to avoid framedrops and deadlocks because of stupid elements */
    if (gst_atomic_int_read (&v4l2src->pool->refcount) == v4l2src->breq.count) {
      GST_LOG_OBJECT (v4l2src, "using memcpy'd buffer");
      buf = gst_buffer_new_and_alloc (i);
      memcpy (GST_BUFFER_DATA (buf), v4l2src->pool->buffers[num].start, i);
      if (!gst_v4l2src_queue_frame(v4l2src, num)) {
	gst_data_unref (GST_DATA (buf));
	return NULL;
      }
    } else {
      GST_LOG_OBJECT (v4l2src, "using mmap'd buffer");
      buf = gst_buffer_new ();
      GST_BUFFER_DATA (buf) = v4l2src->pool->buffers[num].start;
      GST_BUFFER_SIZE (buf) = i;
      GST_BUFFER_FREE_DATA_FUNC (buf) = gst_v4l2src_free_buffer;
      GST_BUFFER_PRIVATE (buf) = &v4l2src->pool->buffers[num];
      /* no need to be careful here, both are > 0, because the element uses them */
      gst_atomic_int_inc (&v4l2src->pool->buffers[num].refcount);
      gst_atomic_int_inc (&v4l2src->pool->refcount);
    }
    GST_BUFFER_MAXSIZE (buf) = v4l2src->pool->buffers[num].length;
    if (v4l2src->use_fixed_fps) {
      GST_BUFFER_TIMESTAMP (buf) = v4l2src->handled * GST_SECOND / fps;
      GST_BUFFER_DURATION (buf) = GST_SECOND / fps;
    } else {
      /* calculate time based on our own clock */
      GST_BUFFER_TIMESTAMP(buf) = GST_TIMEVAL_TO_TIME(v4l2src->pool->buffers[num].buffer.timestamp) -
	  v4l2src->substract_time;
    }
    if (v4l2src->need_writes > 0) {
      v4l2src->cached_buffer = buf;
      for (i = 0; i < v4l2src->need_writes; i++) {
	gst_data_ref (GST_DATA (buf));
      }
    }
  }

  v4l2src->handled++;
  g_signal_emit(G_OBJECT(v4l2src), gst_v4l2src_signals[SIGNAL_FRAME_CAPTURE], 0);

  return GST_DATA (buf);
}

static void
gst_v4l2src_set_property (GObject      *object,
                          guint        prop_id,
                          const GValue *value,
                          GParamSpec   *pspec)
{
	GstV4l2Src *v4l2src;

	g_return_if_fail(GST_IS_V4L2SRC(object));
	v4l2src = GST_V4L2SRC(object);

	switch (prop_id) {
		case ARG_NUMBUFS:
			if (!GST_V4L2_IS_ACTIVE(GST_V4L2ELEMENT(v4l2src))) {
				v4l2src->breq.count = g_value_get_int(value);
			}
			break;

		case ARG_USE_FIXED_FPS:
			if (!GST_V4L2_IS_ACTIVE(GST_V4L2ELEMENT(v4l2src))) {
				v4l2src->use_fixed_fps = g_value_get_boolean(value);
			}
			break;

		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
			break;
	}
}


static void
gst_v4l2src_get_property (GObject    *object,
                          guint      prop_id,
                          GValue     *value,
                          GParamSpec *pspec)
{
	GstV4l2Src *v4l2src;

	g_return_if_fail(GST_IS_V4L2SRC(object));
	v4l2src = GST_V4L2SRC(object);

	switch (prop_id) {
		case ARG_NUMBUFS:
			g_value_set_int(value, v4l2src->breq.count);
			break;

		case ARG_BUFSIZE:
			g_value_set_int(value, v4l2src->format.fmt.pix.sizeimage);
			break;

		case ARG_USE_FIXED_FPS:
			g_value_set_boolean(value, v4l2src->use_fixed_fps);
			break;

		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
			break;
	}
}


static GstElementStateReturn
gst_v4l2src_change_state (GstElement *element)
{
	GstV4l2Src *v4l2src;
	gint transition = GST_STATE_TRANSITION (element);
	GstElementStateReturn parent_return;
	GTimeVal time;

	g_return_val_if_fail(GST_IS_V4L2SRC(element), GST_STATE_FAILURE);
	v4l2src = GST_V4L2SRC(element);

	if (GST_ELEMENT_CLASS (parent_class)->change_state) {
		parent_return = GST_ELEMENT_CLASS (parent_class)->change_state (element);
		if (parent_return != GST_STATE_SUCCESS)
			return parent_return;
	}

	switch (transition) {
		case GST_STATE_NULL_TO_READY:
			if (!gst_v4l2src_get_capture(v4l2src))
				return GST_STATE_FAILURE;
			break;
		case GST_STATE_READY_TO_PAUSED:
			v4l2src->handled = 0;
			v4l2src->need_writes = 0;
			v4l2src->substract_time = 0;
			/* buffer setup moved to capsnego */
			break;
		case GST_STATE_PAUSED_TO_PLAYING:
			/* queue all buffer, start streaming capture */
			if (!gst_v4l2src_capture_start(v4l2src))
				return GST_STATE_FAILURE;
			g_get_current_time(&time);
			v4l2src->substract_time = GST_TIMEVAL_TO_TIME(time) -
			                            v4l2src->substract_time;
			v4l2src->last_seq = 0;
			break;
		case GST_STATE_PLAYING_TO_PAUSED:
			g_get_current_time(&time);
			v4l2src->substract_time = GST_TIMEVAL_TO_TIME(time) -
			                            v4l2src->substract_time;
			/* de-queue all queued buffers */
			if (!gst_v4l2src_capture_stop(v4l2src))
				return GST_STATE_FAILURE;
			break;
		case GST_STATE_PAUSED_TO_READY:
			/* stop capturing, unmap all buffers */
			if (!gst_v4l2src_capture_deinit(v4l2src))
				return GST_STATE_FAILURE;
			break;
		case GST_STATE_READY_TO_NULL:
			break;
	}

	return GST_STATE_SUCCESS;
}


static void
gst_v4l2src_set_clock (GstElement *element,
                           GstClock   *clock)
{
	GST_V4L2SRC(element)->clock = clock;
}