Initial revision

Original commit message from CVS:
Initial revision

4 files changed, 690 insertions, 0 deletions

diff --git a/gst/playondemand/Makefile.am b/gst/playondemand/Makefile.am
new file mode 100644
index 00000000..fc2b93b9
--- /dev/null
+++ b/gst/playondemand/Makefile.am
@@ -0,0 +1,10 @@
+filterdir = $(libdir)/gst
+
+filter_LTLIBRARIES = libgstplayondemand.la
+
+libgstplayondemand_la_SOURCES = gstplayondemand.c
+libgstplayondemand_la_CFLAGS = $(GST_CFLAGS)
+
+noinst_HEADERS = gstplayondemand.h filter.func
+
+# EXTRA_DIST = README
diff --git a/gst/playondemand/filter.func b/gst/playondemand/filter.func
new file mode 100644
index 00000000..6f81c975
--- /dev/null
+++ b/gst/playondemand/filter.func
@@ -0,0 +1,120 @@
+/* -*- C -*- */
+
+_TYPE_ *data_in, *data_out, *filter_data;
+
+filter_data = (_TYPE_ *) filter->buffer;
+num_filter = filter->buffer_size / sizeof(_TYPE_);
+
+/******************************************************************************/
+/* see if we've got any events coming through ... */
+
+do {
+  GST_DEBUG(0, "--- going to events\n");
+
+  while (! filter->eos && GST_IS_EVENT(in)) {
+    if (GST_EVENT_TYPE(in) == GST_EVENT_EOS) {
+      filter->eos = TRUE;
+    } else {
+      gst_pad_push(filter->srcpad, in);
+    }
+
+    in = gst_pad_pull(filter->sinkpad);
+  }
+
+  /******************************************************************************/
+  /* first handle data from the input buffer. */
+
+  GST_DEBUG(0, "--- done with events, going to input\n");
+
+  /* only update the input if there hasn't been an eos yet. */
+  if (! filter->eos) {
+    data_in = (_TYPE_ *) GST_BUFFER_DATA(in);
+    num_in = GST_BUFFER_SIZE(in) / sizeof(_TYPE_);
+
+    w = filter->write;
+
+    /* copy the input data to the filter's internal buffer. */
+    if (filter->follow_stream_tail) {
+      for (j = 0; j < num_in; j++) {
+        filter_data[(w + j) % num_filter] = data_in[j];
+      }
+
+      filter->write = (w + j) % num_filter;
+      
+      /* update the start pointer */
+      if ((filter->start != 0) || ((w + j) >= num_filter)) {
+        filter->start = (filter->write + 1) % num_filter;
+      }
+    } else {
+      for (j = 0; (j < num_in) && ((w + j) < num_filter); j++) {
+        filter_data[w + j] = data_in[j];
+      }
+
+      filter->write += j;
+
+      /* if we're not following the stream tail, the buffer is just a straight
+         buffer. so we need to set eos if we've passed the limit of the internal
+         buffer size. */
+      if ((w + j) >= num_filter) {
+        filter->eos = TRUE;
+      }
+    }
+
+    out = in;
+  } else {
+    j = 0;
+
+    if (filter->srcpool) {
+      out = gst_buffer_new_from_pool(filter->srcpool, 0, 0);
+    } else {
+      out = gst_buffer_new();
+  
+      GST_BUFFER_DATA(out) = (gchar *) g_new(_TYPE_, POD_GSTBUFSIZE / sizeof(_TYPE_));
+      GST_BUFFER_SIZE(out) = POD_GSTBUFSIZE;
+    }
+  }
+
+  /******************************************************************************/
+  /* now handle output data. */
+
+  GST_DEBUG(0, "--- done with input, going to output\n");
+
+  data_out = (_TYPE_ *) GST_BUFFER_DATA(out);
+  num_out = GST_BUFFER_SIZE(out) / sizeof(_TYPE_);
+
+  for (k = 0; k < num_out; k++) {
+    data_out[k] = zero;
+  }
+  
+  /* output play pointer data. */
+  for (t = 0; t < POD_MAX_PLAYS; t++) {
+    offset = filter->plays[t];
+
+    if (offset != G_MAXUINT) {
+      if (filter->follow_stream_tail) {
+        for (k = 0; k < num_out; k++) {
+          data_out[k] = CLAMP(data_out[k] + filter_data[(offset + k) % num_filter], min, max);
+        }
+      } else {
+        for (k = 0; (k < num_out) && ((offset + k) < (w + j)); k++) {
+          data_out[k] = CLAMP(data_out[k] + filter_data[offset + k], min, max);
+        }
+      }
+
+      if ((offset < w) && ((offset + k) >= (w + j))) {
+        filter->plays[t] = G_MAXUINT;
+      } else {
+        filter->plays[t] = (filter->plays[t] + k) % num_filter;
+      }
+    }
+  }
+
+  GST_DEBUG(0, "--- done with output, pushing buffer %p\n", out);
+
+  gst_pad_push(filter->srcpad, out);
+
+  if (! filter->eos) {
+    in = gst_pad_pull(filter->sinkpad);
+  }
+
+} while (! GST_ELEMENT_IS_COTHREAD_STOPPING(elem));
diff --git a/gst/playondemand/gstplayondemand.c b/gst/playondemand/gstplayondemand.c
new file mode 100644
index 00000000..9d2ebff3
--- /dev/null
+++ b/gst/playondemand/gstplayondemand.c
@@ -0,0 +1,448 @@
+/* GStreamer
+ * Copyright (C) 1999-2001 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.
+ */
+
+#include <string.h>
+#include <gst/gst.h>
+#include <libs/audio/gstaudio.h>
+#include "gstplayondemand.h"
+
+
+#define POD_MAX_PLAYS     192     /* maximum number of simultaneous plays */
+#define POD_GSTBUFSIZE    4096    /* gstreamer buffer size to make if no
+                                     bufferpool is available, must be divisible
+                                     by sizeof(gfloat) */
+#define POD_BUFSPERCHUNK  6       /* number of buffers to allocate per chunk in
+                                     sink buffer pool */
+#define POD_BUFFER_SIZE   882000  /* enough space for 10 seconds of 16-bit audio
+                                     at 44100 samples per second ... */
+
+static GstElementDetails play_on_demand_details = {
+  "Play On Demand",
+  "Filter/Effect",
+  "Plays a stream whenever it receives a certain signal",
+  VERSION,
+  "Leif Morgan Johnson <lmjohns3@eos.ncsu.edu>",
+  "(C) 2001",
+};
+
+
+/* Filter signals and args */
+enum {
+  /* FILL ME */
+  PLAY_SIGNAL,
+  RESET_SIGNAL,
+  LAST_SIGNAL
+};
+
+enum {
+  ARG_0,
+  ARG_SILENT,
+  ARG_FOLLOWTAIL,
+  ARG_BUFFERSIZE
+};
+
+static GstPadTemplate*                    
+play_on_demand_sink_factory (void)            
+{                                         
+  static GstPadTemplate *template = NULL; 
+                                          
+  if (!template) {                        
+    template = gst_padtemplate_new 
+      ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
+      gst_caps_append(gst_caps_new ("sink_int",  "audio/raw",
+                                    GST_AUDIO_INT_PAD_TEMPLATE_PROPS),
+                      gst_caps_new ("sink_float", "audio/raw",
+                                    GST_AUDIO_FLOAT_MONO_PAD_TEMPLATE_PROPS)),
+      NULL);
+  }                                       
+  return template;                        
+}
+
+static GstPadTemplate*
+play_on_demand_src_factory (void)
+{
+  static GstPadTemplate *template = NULL;
+  
+  if (!template)
+    template = gst_padtemplate_new 
+      ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
+       gst_caps_append (gst_caps_new ("src_float", "audio/raw",
+                                      GST_AUDIO_FLOAT_MONO_PAD_TEMPLATE_PROPS),
+                        gst_caps_new ("src_int", "audio/raw",
+                                      GST_AUDIO_INT_PAD_TEMPLATE_PROPS)),
+       NULL);
+  
+  return template;
+}
+
+static void		play_on_demand_class_init	 (GstPlayOnDemandClass *klass);
+static void		play_on_demand_init		 (GstPlayOnDemand *filter);
+
+static void		play_on_demand_set_property	 (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
+static void		play_on_demand_get_property      (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
+
+static gint             play_on_demand_parse_caps        (GstPlayOnDemand *filter, GstCaps *caps);
+
+static void		play_on_demand_loop              (GstElement *elem);
+
+static void             play_on_demand_play_handler      (GstElement *elem);
+static void             play_on_demand_reset_handler     (GstElement *elem);
+
+static GstElementClass *parent_class = NULL;
+static guint gst_pod_filter_signals[LAST_SIGNAL] = { 0 };
+
+static GstBufferPool*
+play_on_demand_get_bufferpool (GstPad *pad)
+{
+  GstPlayOnDemand *filter;
+
+  filter = GST_PLAYONDEMAND(gst_pad_get_parent(pad));
+
+  return gst_pad_get_bufferpool(filter->srcpad);
+}
+
+static GstPadNegotiateReturn
+play_on_demand_negotiate_src (GstPad *pad, GstCaps **caps, gpointer *data)
+{
+  GstPlayOnDemand* filter = GST_PLAYONDEMAND(gst_pad_get_parent(pad));
+  
+  if (*caps == NULL) 
+    return GST_PAD_NEGOTIATE_FAIL;
+  
+  if (play_on_demand_parse_caps(filter, *caps))
+    return GST_PAD_NEGOTIATE_FAIL;
+  
+  return gst_pad_negotiate_proxy(pad, filter->sinkpad, caps);
+}
+
+static GstPadNegotiateReturn
+play_on_demand_negotiate_sink (GstPad *pad, GstCaps **caps, gpointer *data)
+{
+  GstPlayOnDemand* filter = GST_PLAYONDEMAND(gst_pad_get_parent(pad));
+  
+  if (*caps == NULL) 
+    return GST_PAD_NEGOTIATE_FAIL;
+  
+  if (play_on_demand_parse_caps(filter, *caps))
+    return GST_PAD_NEGOTIATE_FAIL;
+  
+  return gst_pad_negotiate_proxy(pad, filter->srcpad, caps);
+}	
+
+static gint
+play_on_demand_parse_caps (GstPlayOnDemand *filter, GstCaps *caps)
+{
+  const gchar *format;
+  
+  g_return_val_if_fail(filter != NULL, -1);
+  g_return_val_if_fail(caps   != NULL, -1);
+  
+  format = gst_caps_get_string(caps, "format");
+  
+  filter->rate       = gst_caps_get_int(caps, "rate");
+  filter->channels   = gst_caps_get_int(caps, "channels");
+  
+  if (strcmp(format, "int") == 0) {
+    filter->format     = GST_PLAYONDEMAND_FORMAT_INT;
+    filter->width      = gst_caps_get_int(caps, "width");
+    filter->depth      = gst_caps_get_int(caps, "depth");
+    filter->law        = gst_caps_get_int(caps, "law");
+    filter->endianness = gst_caps_get_int(caps, "endianness");
+    filter->is_signed  = gst_caps_get_int(caps, "signed");
+    if (!filter->silent) {
+      g_print ("PlayOnDemand : channels %d, rate %d\n",  
+               filter->channels, filter->rate);
+      g_print ("PlayOnDemand : format int, bit width %d, endianness %d, signed %s\n",
+               filter->width, filter->endianness, filter->is_signed ? "yes" : "no");
+    }
+  } else if (strcmp(format, "float")==0) {
+    filter->format     = GST_PLAYONDEMAND_FORMAT_FLOAT;
+    filter->layout     = gst_caps_get_string(caps, "layout");
+    filter->intercept  = gst_caps_get_float(caps, "intercept");
+    filter->slope      = gst_caps_get_float(caps, "slope");
+    if (!filter->silent) {
+      g_print ("PlayOnDemand : channels %d, rate %d\n",  
+               filter->channels, filter->rate);
+      g_print ("PlayOnDemand : format float, layout %s, intercept %f, slope %f\n",
+               filter->layout, filter->intercept, filter->slope);
+    }
+  } else  {
+    return -1;
+  }
+  return 0;
+}
+
+
+GType
+gst_play_on_demand_get_type(void) {
+  static GType play_on_demand_type = 0;
+
+  if (! play_on_demand_type) {
+    static const GTypeInfo play_on_demand_info = {
+      sizeof(GstPlayOnDemandClass),
+      NULL,
+      NULL,
+      (GClassInitFunc) play_on_demand_class_init,
+      NULL,
+      NULL,
+      sizeof(GstPlayOnDemand),
+      0,
+      (GInstanceInitFunc) play_on_demand_init,
+    };
+    play_on_demand_type = g_type_register_static(GST_TYPE_ELEMENT, "GstPlayOnDemand", &play_on_demand_info, 0);
+  }
+  return play_on_demand_type;
+}
+
+static void
+play_on_demand_class_init (GstPlayOnDemandClass *klass)
+{
+  GObjectClass    *gobject_class;
+  GstElementClass *gstelement_class;
+
+  gobject_class    = (GObjectClass *)    klass;
+  gstelement_class = (GstElementClass *) klass;
+
+  gst_pod_filter_signals[PLAY_SIGNAL] =
+    g_signal_new("play",
+                 G_TYPE_FROM_CLASS(klass),
+                 G_SIGNAL_RUN_LAST,
+                 G_STRUCT_OFFSET(GstPlayOnDemandClass, play),
+                 NULL, NULL,
+                 g_cclosure_marshal_VOID__VOID,
+                 G_TYPE_NONE, 0);
+
+  gst_pod_filter_signals[RESET_SIGNAL] =
+    g_signal_new("reset",
+                 G_TYPE_FROM_CLASS(klass),
+                 G_SIGNAL_RUN_LAST,
+                 G_STRUCT_OFFSET(GstPlayOnDemandClass, reset),
+                 NULL, NULL,
+                 g_cclosure_marshal_VOID__VOID,
+                 G_TYPE_NONE, 0);
+
+  klass->play  = play_on_demand_play_handler;
+  klass->reset = play_on_demand_reset_handler;
+
+  parent_class = g_type_class_ref(GST_TYPE_ELEMENT);
+
+  g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_SILENT,
+    g_param_spec_boolean("silent","silent","silent",
+                         TRUE, G_PARAM_READWRITE)); // CHECKME
+
+  g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_FOLLOWTAIL,
+    g_param_spec_boolean("follow-stream-tail","follow-stream-tail","follow-stream-tail",
+                         FALSE, G_PARAM_READWRITE));
+
+  g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_BUFFERSIZE,
+    g_param_spec_uint("buffer-size","buffer-size","buffer-size",
+                      0, G_MAXUINT - 1, POD_BUFFER_SIZE, G_PARAM_READWRITE));
+
+  gobject_class->set_property = play_on_demand_set_property;
+  gobject_class->get_property = play_on_demand_get_property;
+}
+
+static void
+play_on_demand_init (GstPlayOnDemand *filter)
+{
+  guint i;
+  
+  filter->sinkpad = gst_pad_new_from_template(play_on_demand_sink_factory(), "sink");
+  gst_pad_set_negotiate_function(filter->sinkpad, play_on_demand_negotiate_sink);
+  gst_pad_set_bufferpool_function(filter->sinkpad, play_on_demand_get_bufferpool);
+
+  filter->srcpad = gst_pad_new_from_template(play_on_demand_src_factory(), "src");
+  gst_pad_set_negotiate_function(filter->srcpad, play_on_demand_negotiate_src);
+  
+  gst_element_add_pad(GST_ELEMENT(filter), filter->sinkpad);
+  gst_element_add_pad(GST_ELEMENT(filter), filter->srcpad);
+
+  gst_element_set_loop_function(GST_ELEMENT(filter), play_on_demand_loop);
+
+  filter->sinkpool = gst_buffer_pool_get_default(POD_GSTBUFSIZE, POD_BUFSPERCHUNK);
+
+  filter->follow_stream_tail = FALSE;  
+  filter->silent      = TRUE;
+
+  filter->buffer      = g_new(gchar, POD_BUFFER_SIZE);
+  filter->buffer_size = POD_BUFFER_SIZE;
+  filter->start       = 0;
+  filter->write       = 0;
+
+  filter->eos         = FALSE;
+
+  /* the plays are stored as an array of buffer offsets. this initializes the
+     array to `blank' values (G_MAXUINT is an invalid index for this filter). */
+  filter->plays  = g_new(guint, POD_MAX_PLAYS);
+  for (i = 0; i < POD_MAX_PLAYS; i++) {
+    filter->plays[i] = G_MAXUINT;
+  }
+}
+
+static void
+play_on_demand_loop (GstElement *elem)
+{
+  GstPlayOnDemand *filter = GST_PLAYONDEMAND(elem);
+  guint            num_in, num_out, num_filter;
+  GstBuffer       *in, *out;
+  register guint   j, k, t;
+  guint            w, offset;
+  
+  g_return_if_fail(filter != NULL);
+  g_return_if_fail(GST_IS_PLAYONDEMAND(filter));
+
+  filter->srcpool = gst_pad_get_bufferpool(filter->srcpad);
+
+  in = gst_pad_pull(filter->sinkpad);
+
+  if (filter->format == GST_PLAYONDEMAND_FORMAT_INT) {
+    if (filter->width == 16) {
+      gint16 min = -32768;
+      gint16 max = 32767;
+      gint16 zero = 0;
+#define _TYPE_ gint16
+#include "filter.func"
+#undef _TYPE_
+    } else if (filter->width == 8) {
+      gint8 min = -128;
+      gint8 max = 127;
+      gint8 zero = 0;
+#define _TYPE_ gint8
+#include "filter.func"
+#undef _TYPE_
+    }
+  } else if (filter->format == GST_PLAYONDEMAND_FORMAT_FLOAT) {
+    gfloat min = -1.0;
+    gfloat max = 1.0;
+    gfloat zero = 0.0;
+#define _TYPE_ gfloat
+#include "filter.func"
+#undef _TYPE_
+  }
+}
+
+static void
+play_on_demand_play_handler(GstElement *elem)
+{
+  GstPlayOnDemand *filter = GST_PLAYONDEMAND(elem);
+  register guint i;
+
+  for (i = 0; i < POD_MAX_PLAYS; i++) {
+    if (filter->plays[i] == G_MAXUINT) {
+      filter->plays[i] = filter->start;
+      break;
+    }
+  }
+}
+
+static void
+play_on_demand_reset_handler(GstElement *elem)
+{
+  GstPlayOnDemand *filter = GST_PLAYONDEMAND(elem);
+  register guint i;
+  
+  for (i = 0; i < POD_MAX_PLAYS; i++) {
+    filter->plays[i] = G_MAXUINT;
+  }
+
+  filter->start = 0;
+  filter->write = 0;
+}
+
+static void
+play_on_demand_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
+{
+  GstPlayOnDemand *filter;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail(GST_IS_PLAYONDEMAND(object));
+  filter = GST_PLAYONDEMAND(object);
+
+  switch (prop_id) {
+  case ARG_BUFFERSIZE:
+    filter->buffer_size = g_value_get_uint(value);
+
+    /* reallocate space for the buffer with the new size values. */
+    g_free(filter->buffer);
+    filter->buffer = g_new(gchar, filter->buffer_size);
+
+    /* reset the play pointers and read/write indexes. */
+    play_on_demand_reset_handler(GST_ELEMENT(filter));
+    break;
+  case ARG_SILENT:
+    filter->silent = g_value_get_boolean(value);
+    break;
+  case ARG_FOLLOWTAIL:
+    filter->follow_stream_tail = g_value_get_boolean(value);
+    play_on_demand_reset_handler(GST_ELEMENT(filter));
+    break;
+  default:
+    break;
+  }
+}
+
+static void
+play_on_demand_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
+{
+  GstPlayOnDemand *filter;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail(GST_IS_PLAYONDEMAND(object));
+  filter = GST_PLAYONDEMAND(object);
+
+  switch (prop_id) {
+  case ARG_BUFFERSIZE:
+    g_value_set_uint(value, filter->buffer_size);
+    break;
+  case ARG_SILENT:
+    g_value_set_boolean(value, filter->silent);
+    break;
+  case ARG_FOLLOWTAIL:
+    g_value_set_boolean(value, filter->follow_stream_tail);
+    break;
+  default:
+    G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+    break;
+  }
+}
+
+static gboolean
+plugin_init (GModule *module, GstPlugin *plugin)
+{
+  GstElementFactory *factory;
+
+  factory = gst_elementfactory_new("playondemand",
+                                   GST_TYPE_PLAYONDEMAND,
+                                   &play_on_demand_details);
+  g_return_val_if_fail(factory != NULL, FALSE);
+  
+  gst_elementfactory_add_padtemplate(factory, play_on_demand_src_factory());
+  gst_elementfactory_add_padtemplate(factory, play_on_demand_sink_factory());
+
+  gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE(factory));
+
+  return TRUE;
+}
+
+GstPluginDesc plugin_desc = {
+  GST_VERSION_MAJOR,
+  GST_VERSION_MINOR,
+  "playondemand",
+  plugin_init
+};
diff --git a/gst/playondemand/gstplayondemand.h b/gst/playondemand/gstplayondemand.h
new file mode 100644
index 00000000..7ca8206e
--- /dev/null
+++ b/gst/playondemand/gstplayondemand.h
@@ -0,0 +1,112 @@
+/* -*- c-basic-offset: 2 -*-
+ * 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.
+ */
+
+
+#ifndef __GST_PLAYONDEMAND_H__
+#define __GST_PLAYONDEMAND_H__
+
+
+#include <config.h>
+#include <gst/gst.h>
+/* #include <gst/meta/audioraw.h> */
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+
+#define GST_TYPE_PLAYONDEMAND \
+  (gst_play_on_demand_get_type())
+#define GST_PLAYONDEMAND(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_PLAYONDEMAND,GstPlayOnDemand))
+#define GST_PLAYONDEMAND_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ULAW,GstPlayOnDemand))
+#define GST_IS_PLAYONDEMAND(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_PLAYONDEMAND))
+#define GST_IS_PLAYONDEMAND_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_PLAYONDEMAND))
+
+typedef struct _GstPlayOnDemand       GstPlayOnDemand;
+typedef struct _GstPlayOnDemandClass  GstPlayOnDemandClass;
+typedef enum   _GstPlayOnDemandFormat GstPlayOnDemandFormat;
+
+enum _GstPlayOnDemandFormat {
+  GST_PLAYONDEMAND_FORMAT_INT,
+  GST_PLAYONDEMAND_FORMAT_FLOAT
+};
+
+struct _GstPlayOnDemand {
+  GstElement element;
+
+  GstPad *sinkpad, *srcpad;
+  GstBufferPool *sinkpool, *srcpool;
+
+  /* these next data elements are for the filter's internal buffers and list of
+     play pointers (offsets in the internal buffers). there are also flags for
+     repeating from the beginning or end of the input stream, and a max buffer
+     size. */
+  gchar    *buffer;
+  guint     buffer_size;
+
+  guint     write;
+  guint     start;
+
+  guint    *plays;
+
+  gboolean  eos;
+
+  gboolean  follow_stream_tail;
+  
+  gboolean  silent;
+  
+  /* the next three are valid for both int and float */
+  GstPlayOnDemandFormat format;
+  guint                 rate;
+  guint                 channels;
+  
+  /* the next five are valid only for format == GST_PLAYONDEMAND_FORMAT_INT */
+  guint    width;
+  guint    depth;
+  guint    endianness;
+  guint    law;
+  gboolean is_signed;
+  
+  /* the next three are valid only for format == GST_PLAYONDEMAND_FORMAT_FLOAT */
+  const gchar *layout;
+  gfloat       slope;
+  gfloat       intercept;
+};
+
+struct _GstPlayOnDemandClass {
+  GstElementClass parent_class;
+
+  void (*play)  (GstElement *elem);
+  void (*reset) (GstElement *elem);
+};
+
+GType gst_play_on_demand_get_type(void);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+
+#endif /* __GST_PLAYONDEMAND_H__ */