ext/jpeg/gstsmokeenc.c - imx-gst-plugins-good - Git at Google

 /* 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., 51 Franklin St, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 /**
  * SECTION:element-smokeenc
  *
  * Encodes images in smoke format.
  */

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

 #include "gstsmokeenc.h"
 #include <gst/video/video.h>

 GST_DEBUG_CATEGORY_STATIC (smokeenc_debug);
 #define GST_CAT_DEFAULT smokeenc_debug


 /* SmokeEnc signals and args */
 enum
 {
   FRAME_ENCODED,
   /* FILL ME */
   LAST_SIGNAL
 };

 #define DEFAULT_PROP_MIN_QUALITY 10
 #define DEFAULT_PROP_MAX_QUALITY 85
 #define DEFAULT_PROP_THRESHOLD 3000
 #define DEFAULT_PROP_KEYFRAME 20

 enum
 {
   PROP_0,
   PROP_MIN_QUALITY,
   PROP_MAX_QUALITY,
   PROP_THRESHOLD,
   PROP_KEYFRAME
       /* FILL ME */
 };

 static void gst_smokeenc_base_init (gpointer g_class);
 static void gst_smokeenc_class_init (GstSmokeEnc * klass);
 static void gst_smokeenc_init (GstSmokeEnc * smokeenc);
 static void gst_smokeenc_finalize (GObject * object);

 static GstStateChangeReturn
 gst_smokeenc_change_state (GstElement * element, GstStateChange transition);

 static GstFlowReturn gst_smokeenc_chain (GstPad * pad, GstBuffer * buf);
 static GstCaps *gst_smokeenc_getcaps (GstPad * pad);
 static gboolean gst_smokeenc_setcaps (GstPad * pad, GstCaps * caps);

 static gboolean gst_smokeenc_resync (GstSmokeEnc * smokeenc);
 static void gst_smokeenc_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec);
 static void gst_smokeenc_get_property (GObject * object, guint prop_id,
     GValue * value, GParamSpec * pspec);

 static GstElementClass *parent_class = NULL;

 GType
 gst_smokeenc_get_type (void)
 {
   static GType smokeenc_type = 0;

   if (!smokeenc_type) {
     static const GTypeInfo smokeenc_info = {
       sizeof (GstSmokeEncClass),
       (GBaseInitFunc) gst_smokeenc_base_init,
       NULL,
       (GClassInitFunc) gst_smokeenc_class_init,
       NULL,
       NULL,
       sizeof (GstSmokeEnc),
       0,
       (GInstanceInitFunc) gst_smokeenc_init,
     };

     smokeenc_type =
         g_type_register_static (GST_TYPE_ELEMENT, "GstSmokeEnc", &smokeenc_info,
         0);
   }
   return smokeenc_type;
 }

 static GstStaticPadTemplate gst_smokeenc_sink_pad_template =
 GST_STATIC_PAD_TEMPLATE ("sink",
     GST_PAD_SINK,
     GST_PAD_ALWAYS,
     GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
     );

 static GstStaticPadTemplate gst_smokeenc_src_pad_template =
 GST_STATIC_PAD_TEMPLATE ("src",
     GST_PAD_SRC,
     GST_PAD_ALWAYS,
     GST_STATIC_CAPS ("video/x-smoke, "
         "width = (int) [ 16, 4096 ], "
         "height = (int) [ 16, 4096 ], " "framerate = (fraction) [ 0/1, MAX ]")
     );

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

   gst_element_class_add_static_pad_template (element_class,
       &gst_smokeenc_sink_pad_template);
   gst_element_class_add_static_pad_template (element_class,
       &gst_smokeenc_src_pad_template);
   gst_element_class_set_static_metadata (element_class, "Smoke video encoder",
       "Codec/Encoder/Video", "Encode images into the Smoke format",
       "Wim Taymans <wim@fluendo.com>");
 }

 static void
 gst_smokeenc_class_init (GstSmokeEnc * klass)
 {
   GObjectClass *gobject_class;
   GstElementClass *gstelement_class;

   gobject_class = (GObjectClass *) klass;
   gstelement_class = (GstElementClass *) klass;

   parent_class = g_type_class_peek_parent (klass);

   gobject_class->finalize = gst_smokeenc_finalize;
   gobject_class->set_property = gst_smokeenc_set_property;
   gobject_class->get_property = gst_smokeenc_get_property;

   g_object_class_install_property (gobject_class, PROP_MIN_QUALITY,
       g_param_spec_int ("qmin", "Qmin", "Minimum quality",
           0, 100, DEFAULT_PROP_MIN_QUALITY,
           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
   g_object_class_install_property (gobject_class, PROP_MAX_QUALITY,
       g_param_spec_int ("qmax", "Qmax", "Maximum quality",
           0, 100, DEFAULT_PROP_MAX_QUALITY,
           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
   g_object_class_install_property (gobject_class, PROP_THRESHOLD,
       g_param_spec_int ("threshold", "Threshold", "Motion estimation threshold",
           0, 100000000, DEFAULT_PROP_THRESHOLD,
           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
   g_object_class_install_property (gobject_class, PROP_KEYFRAME,
       g_param_spec_int ("keyframe", "Keyframe",
           "Insert keyframe every N frames", 1, 100000,
           DEFAULT_PROP_KEYFRAME, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

   gstelement_class->change_state =
       GST_DEBUG_FUNCPTR (gst_smokeenc_change_state);

   GST_DEBUG_CATEGORY_INIT (smokeenc_debug, "smokeenc", 0,
       "Smoke encoding element");
 }

 static void
 gst_smokeenc_init (GstSmokeEnc * smokeenc)
 {
   /* create the sink and src pads */
   smokeenc->sinkpad =
       gst_pad_new_from_static_template (&gst_smokeenc_sink_pad_template,
       "sink");
   gst_pad_set_chain_function (smokeenc->sinkpad, gst_smokeenc_chain);
   gst_pad_set_getcaps_function (smokeenc->sinkpad, gst_smokeenc_getcaps);
   gst_pad_set_setcaps_function (smokeenc->sinkpad, gst_smokeenc_setcaps);
   gst_element_add_pad (GST_ELEMENT (smokeenc), smokeenc->sinkpad);

   smokeenc->srcpad =
       gst_pad_new_from_static_template (&gst_smokeenc_src_pad_template, "src");
   gst_pad_set_getcaps_function (smokeenc->srcpad, gst_smokeenc_getcaps);
   gst_pad_use_fixed_caps (smokeenc->srcpad);
   gst_element_add_pad (GST_ELEMENT (smokeenc), smokeenc->srcpad);

   smokeenc->min_quality = DEFAULT_PROP_MIN_QUALITY;
   smokeenc->max_quality = DEFAULT_PROP_MAX_QUALITY;
   smokeenc->threshold = DEFAULT_PROP_THRESHOLD;
   smokeenc->keyframe = DEFAULT_PROP_KEYFRAME;
 }

 static void
 gst_smokeenc_finalize (GObject * object)
 {
   GstSmokeEnc *enc = GST_SMOKEENC (object);

   if (enc->info)
     smokecodec_info_free (enc->info);

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

 static GstCaps *
 gst_smokeenc_getcaps (GstPad * pad)
 {
   GstSmokeEnc *smokeenc = GST_SMOKEENC (gst_pad_get_parent (pad));
   GstPad *otherpad;
   GstCaps *result, *caps;
   const GstCaps *tcaps;
   const char *name;
   int i;
   GstStructure *structure = NULL;

   /* we want to proxy properties like width, height and framerate from the
      other end of the element */
   otherpad = (pad == smokeenc->srcpad) ? smokeenc->sinkpad : smokeenc->srcpad;

   /* get template caps, we always need this to fiter the peer caps */
   tcaps = gst_pad_get_pad_template_caps (otherpad);

   /* get any constraints on the peer pad */
   caps = gst_pad_peer_get_caps (otherpad);

   if (caps == NULL)
     caps = gst_caps_copy (tcaps);
   else
     caps = gst_caps_make_writable (caps);

   /* intersect with the template */
   result = gst_caps_intersect (caps, tcaps);
   gst_caps_unref (caps);

   if (pad == smokeenc->srcpad) {
     name = "video/x-smoke";
   } else {
     name = "video/x-raw-yuv";
   }

   /* we can only copy width, height, framerate from one side to the other */
   for (i = 0; i < gst_caps_get_size (result); i++) {
     structure = gst_caps_get_structure (result, i);

     gst_structure_set_name (structure, name);
     gst_structure_remove_field (structure, "format");
     /* ... but for the sink pad, we only do I420 anyway, so add that */
     if (pad == smokeenc->sinkpad) {
       gst_structure_set (structure, "format", GST_TYPE_FOURCC,
           GST_STR_FOURCC ("I420"), NULL);
     }
   }

   gst_object_unref (smokeenc);

   return result;
 }

 static gboolean
 gst_smokeenc_setcaps (GstPad * pad, GstCaps * caps)
 {
   GstSmokeEnc *smokeenc;
   GstStructure *structure;
   const GValue *framerate;
   gboolean ret;
   GstCaps *srccaps;

   smokeenc = GST_SMOKEENC (gst_pad_get_parent (pad));

   structure = gst_caps_get_structure (caps, 0);
   framerate = gst_structure_get_value (structure, "framerate");
   if (framerate) {
     smokeenc->fps_num = gst_value_get_fraction_numerator (framerate);
     smokeenc->fps_denom = gst_value_get_fraction_denominator (framerate);
   } else {
     smokeenc->fps_num = 0;
     smokeenc->fps_denom = 1;
   }

   gst_structure_get_int (structure, "width", &smokeenc->width);
   gst_structure_get_int (structure, "height", &smokeenc->height);

   if ((smokeenc->width & 0x0f) != 0 || (smokeenc->height & 0x0f) != 0)
     goto width_or_height_notx16;

   if (!gst_smokeenc_resync (smokeenc))
     goto init_failed;

   srccaps = gst_caps_new_simple ("video/x-smoke",
       "width", G_TYPE_INT, smokeenc->width,
       "height", G_TYPE_INT, smokeenc->height,
       "framerate", GST_TYPE_FRACTION, smokeenc->fps_num, smokeenc->fps_denom,
       NULL);

   ret = gst_pad_set_caps (smokeenc->srcpad, srccaps);
   gst_caps_unref (srccaps);

   gst_object_unref (smokeenc);

   return ret;

 width_or_height_notx16:
   {
     GST_WARNING_OBJECT (smokeenc, "width and height must be multiples of 16"
         ", %dx%d not allowed", smokeenc->width, smokeenc->height);
     gst_object_unref (smokeenc);
     return FALSE;
   }
 init_failed:
   {
     GST_WARNING_OBJECT (smokeenc, "could not init decoder");
     gst_object_unref (smokeenc);
     return FALSE;
   }
 }

 static gboolean
 gst_smokeenc_resync (GstSmokeEnc * smokeenc)
 {
   int ret;

   GST_DEBUG ("resync: %dx%d@%d/%dfps", smokeenc->width, smokeenc->height,
       smokeenc->fps_num, smokeenc->fps_denom);

   if (smokeenc->info)
     smokecodec_info_free (smokeenc->info);

   ret = smokecodec_encode_new (&smokeenc->info, smokeenc->width,
       smokeenc->height, smokeenc->fps_num, smokeenc->fps_denom);

   if (ret != SMOKECODEC_OK)
     goto init_failed;

   smokecodec_set_quality (smokeenc->info, smokeenc->min_quality,
       smokeenc->max_quality);

   GST_DEBUG ("resync done");
   return TRUE;

   /* ERRORS */
 init_failed:
   {
     GST_WARNING_OBJECT (smokeenc, "smokecodec_encode_new() failed: %d", ret);
     return FALSE;
   }
 }

 static GstFlowReturn
 gst_smokeenc_chain (GstPad * pad, GstBuffer * buf)
 {
   GstSmokeEnc *smokeenc;
   guchar *data, *outdata;
   gulong size;
   gint outsize;
   guint encsize;
   GstBuffer *outbuf;
   SmokeCodecFlags flags;
   GstFlowReturn ret;

   smokeenc = GST_SMOKEENC (GST_OBJECT_PARENT (pad));

   data = GST_BUFFER_DATA (buf);
   size = GST_BUFFER_SIZE (buf);

   GST_LOG_OBJECT (smokeenc, "got buffer of %lu bytes", size);

   if (smokeenc->need_header) {
     outbuf = gst_buffer_new_and_alloc (256);
     outdata = GST_BUFFER_DATA (outbuf);

     GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buf);
     GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buf);

     smokecodec_encode_id (smokeenc->info, outdata, &encsize);

     GST_BUFFER_SIZE (outbuf) = encsize;
     gst_buffer_set_caps (outbuf, GST_PAD_CAPS (smokeenc->srcpad));

     ret = gst_pad_push (smokeenc->srcpad, outbuf);
     if (ret != GST_FLOW_OK)
       goto done;

     smokeenc->need_header = FALSE;
   }

   encsize = outsize = smokeenc->width * smokeenc->height * 3;
   outbuf = gst_buffer_new_and_alloc (outsize);
   outdata = GST_BUFFER_DATA (outbuf);

   GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buf);
   GST_BUFFER_DURATION (outbuf) =
       gst_util_uint64_scale_int (GST_SECOND, smokeenc->fps_denom,
       smokeenc->fps_num);
   gst_buffer_set_caps (outbuf, GST_PAD_CAPS (smokeenc->srcpad));

   flags = 0;
   if ((smokeenc->frame % smokeenc->keyframe) == 0) {
     flags |= SMOKECODEC_KEYFRAME;
   }
   smokecodec_set_quality (smokeenc->info, smokeenc->min_quality,
       smokeenc->max_quality);
   smokecodec_set_threshold (smokeenc->info, smokeenc->threshold);
   smokecodec_encode (smokeenc->info, data, flags, outdata, &encsize);
   gst_buffer_unref (buf);

   GST_BUFFER_SIZE (outbuf) = encsize;
   GST_BUFFER_OFFSET (outbuf) = smokeenc->frame;
   GST_BUFFER_OFFSET_END (outbuf) = smokeenc->frame + 1;

   ret = gst_pad_push (smokeenc->srcpad, outbuf);

   smokeenc->frame++;

 done:

   return ret;
 }

 static void
 gst_smokeenc_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec)
 {
   GstSmokeEnc *smokeenc;

   g_return_if_fail (GST_IS_SMOKEENC (object));
   smokeenc = GST_SMOKEENC (object);

   switch (prop_id) {
     case PROP_MIN_QUALITY:
       smokeenc->min_quality = g_value_get_int (value);
       break;
     case PROP_MAX_QUALITY:
       smokeenc->max_quality = g_value_get_int (value);
       break;
     case PROP_THRESHOLD:
       smokeenc->threshold = g_value_get_int (value);
       break;
     case PROP_KEYFRAME:
       smokeenc->keyframe = g_value_get_int (value);
       break;
     default:
       break;
   }
 }

 static void
 gst_smokeenc_get_property (GObject * object, guint prop_id, GValue * value,
     GParamSpec * pspec)
 {
   GstSmokeEnc *smokeenc;

   g_return_if_fail (GST_IS_SMOKEENC (object));
   smokeenc = GST_SMOKEENC (object);

   switch (prop_id) {
     case PROP_MIN_QUALITY:
       g_value_set_int (value, smokeenc->min_quality);
       break;
     case PROP_MAX_QUALITY:
       g_value_set_int (value, smokeenc->max_quality);
       break;
     case PROP_THRESHOLD:
       g_value_set_int (value, smokeenc->threshold);
       break;
     case PROP_KEYFRAME:
       g_value_set_int (value, smokeenc->keyframe);
       break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
   }
 }

 static GstStateChangeReturn
 gst_smokeenc_change_state (GstElement * element, GstStateChange transition)
 {
   GstStateChangeReturn ret;
   GstSmokeEnc *enc;

   enc = GST_SMOKEENC (element);

   switch (transition) {
     case GST_STATE_CHANGE_READY_TO_PAUSED:
       /* reset the initial video state */
       enc->width = 0;
       enc->height = 0;
       enc->frame = 0;
       enc->need_header = TRUE;
     default:
       break;
   }

   ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
   if (ret != GST_STATE_CHANGE_SUCCESS)
     return ret;

   switch (transition) {
     case GST_STATE_CHANGE_PAUSED_TO_READY:
       break;
     default:
       break;
   }

   return ret;
 }
	/* 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., 51 Franklin St, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*/
	/**
	* SECTION:element-smokeenc
	*
	* Encodes images in smoke format.
	*/

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

	#include "gstsmokeenc.h"
	#include <gst/video/video.h>

	GST_DEBUG_CATEGORY_STATIC (smokeenc_debug);
	#define GST_CAT_DEFAULT smokeenc_debug


	/* SmokeEnc signals and args */
	enum
	{
	FRAME_ENCODED,
	/* FILL ME */
	LAST_SIGNAL
	};

	#define DEFAULT_PROP_MIN_QUALITY 10
	#define DEFAULT_PROP_MAX_QUALITY 85
	#define DEFAULT_PROP_THRESHOLD 3000
	#define DEFAULT_PROP_KEYFRAME 20

	enum
	{
	PROP_0,
	PROP_MIN_QUALITY,
	PROP_MAX_QUALITY,
	PROP_THRESHOLD,
	PROP_KEYFRAME
	/* FILL ME */
	};

	static void gst_smokeenc_base_init (gpointer g_class);
	static void gst_smokeenc_class_init (GstSmokeEnc * klass);
	static void gst_smokeenc_init (GstSmokeEnc * smokeenc);
	static void gst_smokeenc_finalize (GObject * object);

	static GstStateChangeReturn
	gst_smokeenc_change_state (GstElement * element, GstStateChange transition);

	static GstFlowReturn gst_smokeenc_chain (GstPad * pad, GstBuffer * buf);
	static GstCaps gst_smokeenc_getcaps (GstPad pad);
	static gboolean gst_smokeenc_setcaps (GstPad * pad, GstCaps * caps);

	static gboolean gst_smokeenc_resync (GstSmokeEnc * smokeenc);
	static void gst_smokeenc_set_property (GObject * object, guint prop_id,
	const GValue * value, GParamSpec * pspec);
	static void gst_smokeenc_get_property (GObject * object, guint prop_id,
	GValue * value, GParamSpec * pspec);

	static GstElementClass *parent_class = NULL;

	GType
	gst_smokeenc_get_type (void)
	{
	static GType smokeenc_type = 0;

	if (!smokeenc_type) {
	static const GTypeInfo smokeenc_info = {
	sizeof (GstSmokeEncClass),
	(GBaseInitFunc) gst_smokeenc_base_init,
	NULL,
	(GClassInitFunc) gst_smokeenc_class_init,
	NULL,
	NULL,
	sizeof (GstSmokeEnc),
	0,
	(GInstanceInitFunc) gst_smokeenc_init,
	};

	smokeenc_type =
	g_type_register_static (GST_TYPE_ELEMENT, "GstSmokeEnc", &smokeenc_info,
	0);
	}
	return smokeenc_type;
	}

	static GstStaticPadTemplate gst_smokeenc_sink_pad_template =
	GST_STATIC_PAD_TEMPLATE ("sink",
	GST_PAD_SINK,
	GST_PAD_ALWAYS,
	GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
	);

	static GstStaticPadTemplate gst_smokeenc_src_pad_template =
	GST_STATIC_PAD_TEMPLATE ("src",
	GST_PAD_SRC,
	GST_PAD_ALWAYS,
	GST_STATIC_CAPS ("video/x-smoke, "
	"width = (int) [ 16, 4096 ], "
	"height = (int) [ 16, 4096 ], " "framerate = (fraction) [ 0/1, MAX ]")
	);

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

	gst_element_class_add_static_pad_template (element_class,
	&gst_smokeenc_sink_pad_template);
	gst_element_class_add_static_pad_template (element_class,
	&gst_smokeenc_src_pad_template);
	gst_element_class_set_static_metadata (element_class, "Smoke video encoder",
	"Codec/Encoder/Video", "Encode images into the Smoke format",
	"Wim Taymans <wim@fluendo.com>");
	}

	static void
	gst_smokeenc_class_init (GstSmokeEnc * klass)
	{
	GObjectClass *gobject_class;
	GstElementClass *gstelement_class;

	gobject_class = (GObjectClass *) klass;
	gstelement_class = (GstElementClass *) klass;

	parent_class = g_type_class_peek_parent (klass);

	gobject_class->finalize = gst_smokeenc_finalize;
	gobject_class->set_property = gst_smokeenc_set_property;
	gobject_class->get_property = gst_smokeenc_get_property;

	g_object_class_install_property (gobject_class, PROP_MIN_QUALITY,
	g_param_spec_int ("qmin", "Qmin", "Minimum quality",
	0, 100, DEFAULT_PROP_MIN_QUALITY,
	G_PARAM_READWRITE \| G_PARAM_STATIC_STRINGS));
	g_object_class_install_property (gobject_class, PROP_MAX_QUALITY,
	g_param_spec_int ("qmax", "Qmax", "Maximum quality",
	0, 100, DEFAULT_PROP_MAX_QUALITY,
	G_PARAM_READWRITE \| G_PARAM_STATIC_STRINGS));
	g_object_class_install_property (gobject_class, PROP_THRESHOLD,
	g_param_spec_int ("threshold", "Threshold", "Motion estimation threshold",
	0, 100000000, DEFAULT_PROP_THRESHOLD,
	G_PARAM_READWRITE \| G_PARAM_STATIC_STRINGS));
	g_object_class_install_property (gobject_class, PROP_KEYFRAME,
	g_param_spec_int ("keyframe", "Keyframe",
	"Insert keyframe every N frames", 1, 100000,
	DEFAULT_PROP_KEYFRAME, G_PARAM_READWRITE \| G_PARAM_STATIC_STRINGS));

	gstelement_class->change_state =
	GST_DEBUG_FUNCPTR (gst_smokeenc_change_state);

	GST_DEBUG_CATEGORY_INIT (smokeenc_debug, "smokeenc", 0,
	"Smoke encoding element");
	}

	static void
	gst_smokeenc_init (GstSmokeEnc * smokeenc)
	{
	/* create the sink and src pads */
	smokeenc->sinkpad =
	gst_pad_new_from_static_template (&gst_smokeenc_sink_pad_template,
	"sink");
	gst_pad_set_chain_function (smokeenc->sinkpad, gst_smokeenc_chain);
	gst_pad_set_getcaps_function (smokeenc->sinkpad, gst_smokeenc_getcaps);
	gst_pad_set_setcaps_function (smokeenc->sinkpad, gst_smokeenc_setcaps);
	gst_element_add_pad (GST_ELEMENT (smokeenc), smokeenc->sinkpad);

	smokeenc->srcpad =
	gst_pad_new_from_static_template (&gst_smokeenc_src_pad_template, "src");
	gst_pad_set_getcaps_function (smokeenc->srcpad, gst_smokeenc_getcaps);
	gst_pad_use_fixed_caps (smokeenc->srcpad);
	gst_element_add_pad (GST_ELEMENT (smokeenc), smokeenc->srcpad);

	smokeenc->min_quality = DEFAULT_PROP_MIN_QUALITY;
	smokeenc->max_quality = DEFAULT_PROP_MAX_QUALITY;
	smokeenc->threshold = DEFAULT_PROP_THRESHOLD;
	smokeenc->keyframe = DEFAULT_PROP_KEYFRAME;
	}

	static void
	gst_smokeenc_finalize (GObject * object)
	{
	GstSmokeEnc *enc = GST_SMOKEENC (object);

	if (enc->info)
	smokecodec_info_free (enc->info);

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

	static GstCaps *
	gst_smokeenc_getcaps (GstPad * pad)
	{
	GstSmokeEnc *smokeenc = GST_SMOKEENC (gst_pad_get_parent (pad));
	GstPad *otherpad;
	GstCaps result, caps;
	const GstCaps *tcaps;
	const char *name;
	int i;
	GstStructure *structure = NULL;

	/* we want to proxy properties like width, height and framerate from the
	other end of the element */
	otherpad = (pad == smokeenc->srcpad) ? smokeenc->sinkpad : smokeenc->srcpad;

	/* get template caps, we always need this to fiter the peer caps */
	tcaps = gst_pad_get_pad_template_caps (otherpad);

	/* get any constraints on the peer pad */
	caps = gst_pad_peer_get_caps (otherpad);

	if (caps == NULL)
	caps = gst_caps_copy (tcaps);
	else
	caps = gst_caps_make_writable (caps);

	/* intersect with the template */
	result = gst_caps_intersect (caps, tcaps);
	gst_caps_unref (caps);

	if (pad == smokeenc->srcpad) {
	name = "video/x-smoke";
	} else {
	name = "video/x-raw-yuv";
	}

	/* we can only copy width, height, framerate from one side to the other */
	for (i = 0; i < gst_caps_get_size (result); i++) {
	structure = gst_caps_get_structure (result, i);

	gst_structure_set_name (structure, name);
	gst_structure_remove_field (structure, "format");
	/* ... but for the sink pad, we only do I420 anyway, so add that */
	if (pad == smokeenc->sinkpad) {
	gst_structure_set (structure, "format", GST_TYPE_FOURCC,
	GST_STR_FOURCC ("I420"), NULL);
	}
	}

	gst_object_unref (smokeenc);

	return result;
	}

	static gboolean
	gst_smokeenc_setcaps (GstPad * pad, GstCaps * caps)
	{
	GstSmokeEnc *smokeenc;
	GstStructure *structure;
	const GValue *framerate;
	gboolean ret;
	GstCaps *srccaps;

	smokeenc = GST_SMOKEENC (gst_pad_get_parent (pad));

	structure = gst_caps_get_structure (caps, 0);
	framerate = gst_structure_get_value (structure, "framerate");
	if (framerate) {
	smokeenc->fps_num = gst_value_get_fraction_numerator (framerate);
	smokeenc->fps_denom = gst_value_get_fraction_denominator (framerate);
	} else {
	smokeenc->fps_num = 0;
	smokeenc->fps_denom = 1;
	}

	gst_structure_get_int (structure, "width", &smokeenc->width);
	gst_structure_get_int (structure, "height", &smokeenc->height);

	if ((smokeenc->width & 0x0f) != 0 \|\| (smokeenc->height & 0x0f) != 0)
	goto width_or_height_notx16;

	if (!gst_smokeenc_resync (smokeenc))
	goto init_failed;

	srccaps = gst_caps_new_simple ("video/x-smoke",
	"width", G_TYPE_INT, smokeenc->width,
	"height", G_TYPE_INT, smokeenc->height,
	"framerate", GST_TYPE_FRACTION, smokeenc->fps_num, smokeenc->fps_denom,
	NULL);

	ret = gst_pad_set_caps (smokeenc->srcpad, srccaps);
	gst_caps_unref (srccaps);

	gst_object_unref (smokeenc);

	return ret;

	width_or_height_notx16:
	{
	GST_WARNING_OBJECT (smokeenc, "width and height must be multiples of 16"
	", %dx%d not allowed", smokeenc->width, smokeenc->height);
	gst_object_unref (smokeenc);
	return FALSE;
	}
	init_failed:
	{
	GST_WARNING_OBJECT (smokeenc, "could not init decoder");
	gst_object_unref (smokeenc);
	return FALSE;
	}
	}

	static gboolean
	gst_smokeenc_resync (GstSmokeEnc * smokeenc)
	{
	int ret;

	GST_DEBUG ("resync: %dx%d@%d/%dfps", smokeenc->width, smokeenc->height,
	smokeenc->fps_num, smokeenc->fps_denom);

	if (smokeenc->info)
	smokecodec_info_free (smokeenc->info);

	ret = smokecodec_encode_new (&smokeenc->info, smokeenc->width,
	smokeenc->height, smokeenc->fps_num, smokeenc->fps_denom);

	if (ret != SMOKECODEC_OK)
	goto init_failed;

	smokecodec_set_quality (smokeenc->info, smokeenc->min_quality,
	smokeenc->max_quality);

	GST_DEBUG ("resync done");
	return TRUE;

	/* ERRORS */
	init_failed:
	{
	GST_WARNING_OBJECT (smokeenc, "smokecodec_encode_new() failed: %d", ret);
	return FALSE;
	}
	}

	static GstFlowReturn
	gst_smokeenc_chain (GstPad * pad, GstBuffer * buf)
	{
	GstSmokeEnc *smokeenc;
	guchar data, outdata;
	gulong size;
	gint outsize;
	guint encsize;
	GstBuffer *outbuf;
	SmokeCodecFlags flags;
	GstFlowReturn ret;

	smokeenc = GST_SMOKEENC (GST_OBJECT_PARENT (pad));

	data = GST_BUFFER_DATA (buf);
	size = GST_BUFFER_SIZE (buf);

	GST_LOG_OBJECT (smokeenc, "got buffer of %lu bytes", size);

	if (smokeenc->need_header) {
	outbuf = gst_buffer_new_and_alloc (256);
	outdata = GST_BUFFER_DATA (outbuf);

	GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buf);
	GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buf);

	smokecodec_encode_id (smokeenc->info, outdata, &encsize);

	GST_BUFFER_SIZE (outbuf) = encsize;
	gst_buffer_set_caps (outbuf, GST_PAD_CAPS (smokeenc->srcpad));

	ret = gst_pad_push (smokeenc->srcpad, outbuf);
	if (ret != GST_FLOW_OK)
	goto done;

	smokeenc->need_header = FALSE;
	}

	encsize = outsize = smokeenc->width * smokeenc->height * 3;
	outbuf = gst_buffer_new_and_alloc (outsize);
	outdata = GST_BUFFER_DATA (outbuf);

	GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buf);
	GST_BUFFER_DURATION (outbuf) =
	gst_util_uint64_scale_int (GST_SECOND, smokeenc->fps_denom,
	smokeenc->fps_num);
	gst_buffer_set_caps (outbuf, GST_PAD_CAPS (smokeenc->srcpad));

	flags = 0;
	if ((smokeenc->frame % smokeenc->keyframe) == 0) {
	flags \|= SMOKECODEC_KEYFRAME;
	}
	smokecodec_set_quality (smokeenc->info, smokeenc->min_quality,
	smokeenc->max_quality);
	smokecodec_set_threshold (smokeenc->info, smokeenc->threshold);
	smokecodec_encode (smokeenc->info, data, flags, outdata, &encsize);
	gst_buffer_unref (buf);

	GST_BUFFER_SIZE (outbuf) = encsize;
	GST_BUFFER_OFFSET (outbuf) = smokeenc->frame;
	GST_BUFFER_OFFSET_END (outbuf) = smokeenc->frame + 1;

	ret = gst_pad_push (smokeenc->srcpad, outbuf);

	smokeenc->frame++;

	done:

	return ret;
	}

	static void
	gst_smokeenc_set_property (GObject * object, guint prop_id,
	const GValue * value, GParamSpec * pspec)
	{
	GstSmokeEnc *smokeenc;

	g_return_if_fail (GST_IS_SMOKEENC (object));
	smokeenc = GST_SMOKEENC (object);

	switch (prop_id) {
	case PROP_MIN_QUALITY:
	smokeenc->min_quality = g_value_get_int (value);
	break;
	case PROP_MAX_QUALITY:
	smokeenc->max_quality = g_value_get_int (value);
	break;
	case PROP_THRESHOLD:
	smokeenc->threshold = g_value_get_int (value);
	break;
	case PROP_KEYFRAME:
	smokeenc->keyframe = g_value_get_int (value);
	break;
	default:
	break;
	}
	}

	static void
	gst_smokeenc_get_property (GObject * object, guint prop_id, GValue * value,
	GParamSpec * pspec)
	{
	GstSmokeEnc *smokeenc;

	g_return_if_fail (GST_IS_SMOKEENC (object));
	smokeenc = GST_SMOKEENC (object);

	switch (prop_id) {
	case PROP_MIN_QUALITY:
	g_value_set_int (value, smokeenc->min_quality);
	break;
	case PROP_MAX_QUALITY:
	g_value_set_int (value, smokeenc->max_quality);
	break;
	case PROP_THRESHOLD:
	g_value_set_int (value, smokeenc->threshold);
	break;
	case PROP_KEYFRAME:
	g_value_set_int (value, smokeenc->keyframe);
	break;
	default:
	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
	break;
	}
	}

	static GstStateChangeReturn
	gst_smokeenc_change_state (GstElement * element, GstStateChange transition)
	{
	GstStateChangeReturn ret;
	GstSmokeEnc *enc;

	enc = GST_SMOKEENC (element);

	switch (transition) {
	case GST_STATE_CHANGE_READY_TO_PAUSED:
	/* reset the initial video state */
	enc->width = 0;
	enc->height = 0;
	enc->frame = 0;
	enc->need_header = TRUE;
	default:
	break;
	}

	ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
	if (ret != GST_STATE_CHANGE_SUCCESS)
	return ret;

	switch (transition) {
	case GST_STATE_CHANGE_PAUSED_TO_READY:
	break;
	default:
	break;
	}

	return ret;
	}