gstreamer/gst/playondemand/gstplayondemand.c

/* 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.
 */


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

#include "gstplayondemand.h"

/* in these files, a 'tick' is a discrete unit of time, usually around the 1ms
 * range. a tick is not divisible into smaller units of time. 1ms is probably
 * way beyond what a real computer can actually keep track of, but hey ... */

/* some default values */
#define GST_POD_MAX_PLAYS    100        /* maximum simultaneous plays */
#define GST_POD_BUFFER_TIME  5.0        /* buffer length in seconds */
#define GST_POD_TICK_RATE    1e-6       /* ticks per second */

/* buffer pool fallback values ... use if no buffer pool is available */
#define GST_POD_BUFPOOL_SIZE 4096
#define GST_POD_BUFPOOL_NUM  6


static GstElementDetails play_on_demand_details = {
  "Play On Demand",
  "Filter/Editor/Audio",
  "Schedule a stream to play at specific times, or when a signal is received",
  "Leif Morgan Johnson <leif@ambient.2y.net>",
};


static GstStaticPadTemplate play_on_demand_sink_template =
    GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_AUDIO_INT_PAD_TEMPLATE_CAPS "; "
        GST_AUDIO_FLOAT_STANDARD_PAD_TEMPLATE_CAPS)
    );

static GstStaticPadTemplate play_on_demand_src_template =
    GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_AUDIO_INT_PAD_TEMPLATE_CAPS "; "
        GST_AUDIO_FLOAT_STANDARD_PAD_TEMPLATE_CAPS)
    );


/* GObject functionality */
static void play_on_demand_class_init (GstPlayOnDemandClass * klass);
static void play_on_demand_base_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 void play_on_demand_dispose (GObject * object);

/* GStreamer functionality */
static GstPadLinkReturn play_on_demand_pad_link (GstPad * pad,
    const GstCaps * caps);
static void play_on_demand_loop (GstElement * elem);
static void play_on_demand_set_clock (GstElement * elem, GstClock * clock);

/* signal handlers */
static void play_on_demand_play_handler (GstElement * elem);
static void play_on_demand_clear_handler (GstElement * elem);
static void play_on_demand_reset_handler (GstElement * elem);

/* utility functions */
static void play_on_demand_add_play_pointer (GstPlayOnDemand * filter,
    guint pos);
static void play_on_demand_resize_buffer (GstPlayOnDemand * filter);

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),
      (GBaseInitFunc) play_on_demand_base_init,
      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;
}


/* signals and properties */
enum
{
  /* add signals here */
  PLAYED_SIGNAL,
  STOPPED_SIGNAL,
  PLAY_SIGNAL,
  CLEAR_SIGNAL,
  RESET_SIGNAL,
  LAST_SIGNAL
};

enum
{
  PROP_0,
  PROP_MUTE,
  PROP_BUFFER_TIME,
  PROP_MAX_PLAYS,
  PROP_TICK_RATE,
  PROP_TOTAL_TICKS,
  PROP_TICKS
};

static guint gst_pod_filter_signals[LAST_SIGNAL] = { 0 };

static GstElementClass *parent_class = NULL;

static void
play_on_demand_base_init (GstPlayOnDemandClass * klass)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&play_on_demand_src_template));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&play_on_demand_sink_template));
  gst_element_class_set_details (element_class, &play_on_demand_details);
}

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[PLAYED_SIGNAL] =
      g_signal_new ("played", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstPlayOnDemandClass, played),
      NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);

  gst_pod_filter_signals[STOPPED_SIGNAL] =
      g_signal_new ("stopped", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstPlayOnDemandClass, stopped),
      NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);

  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[CLEAR_SIGNAL] =
      g_signal_new ("clear", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstPlayOnDemandClass, clear),
      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->clear = play_on_demand_clear_handler;
  klass->reset = play_on_demand_reset_handler;

  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);

  gobject_class->set_property = play_on_demand_set_property;
  gobject_class->get_property = play_on_demand_get_property;
  gobject_class->dispose = play_on_demand_dispose;

  gstelement_class->set_clock = play_on_demand_set_clock;

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_MUTE,
      g_param_spec_boolean ("mute", "Silence output", "Do not output any sound",
          FALSE, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_BUFFER_TIME,
      g_param_spec_float ("buffer-time", "Buffer length in seconds",
          "Number of seconds of audio the buffer holds", 0.0, G_MAXFLOAT,
          GST_POD_BUFFER_TIME, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_MAX_PLAYS,
      g_param_spec_uint ("max-plays", "Maximum simultaneous playbacks",
          "Maximum allowed number of simultaneous plays from the buffer", 1,
          G_MAXUINT, GST_POD_MAX_PLAYS, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TICK_RATE,
      g_param_spec_float ("tick-rate", "Tick rate (ticks/second)",
          "The rate of musical ticks, the smallest time unit in a song", 0,
          G_MAXFLOAT, GST_POD_TICK_RATE,
          G_PARAM_READWRITE | G_PARAM_CONSTRUCT));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TOTAL_TICKS,
      g_param_spec_uint ("total-ticks", "Total number of ticks",
          "Total number of ticks in the tick array", 1, G_MAXUINT, 1,
          G_PARAM_READWRITE | G_PARAM_CONSTRUCT));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TICKS,
      g_param_spec_pointer ("ticks", "Ticks to play sample on",
          "An array of ticks (musical times) at which to play the sample",
          G_PARAM_READWRITE));
}

static void
play_on_demand_init (GstPlayOnDemand * filter)
{
  filter->srcpad =
      gst_pad_new_from_template (gst_static_pad_template_get
      (&play_on_demand_src_template), "src");
  filter->sinkpad =
      gst_pad_new_from_template (gst_static_pad_template_get
      (&play_on_demand_sink_template), "sink");

  gst_pad_set_link_function (filter->sinkpad, play_on_demand_pad_link);

  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->clock = NULL;

  filter->rate = 0;

  filter->ticks = g_new (guint32, filter->total_ticks / 32 + 1);
  filter->plays = g_new (guint, filter->max_plays);

  play_on_demand_resize_buffer (filter);
  play_on_demand_reset_handler (GST_ELEMENT (filter));
}

static void
play_on_demand_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstPlayOnDemand *filter;
  register guint i;
  guint new_size, min_size, *new_plays;
  guint *new_ticks;

  g_return_if_fail (GST_IS_PLAYONDEMAND (object));
  filter = GST_PLAYONDEMAND (object);

  switch (prop_id) {
    case PROP_MUTE:
      filter->mute = g_value_get_boolean (value);
      break;
    case PROP_BUFFER_TIME:
      filter->buffer_time = g_value_get_float (value);
      play_on_demand_resize_buffer (filter);

      /* clear out now-invalid play pointers */
      for (i = 0; i < filter->max_plays; i++)
        filter->plays[i] = G_MAXUINT;

      break;
    case PROP_MAX_PLAYS:
      new_size = g_value_get_uint (value);
      min_size = (new_size < filter->max_plays) ? new_size : filter->max_plays;

      new_plays = g_new (guint, new_size);
      for (i = 0; i < min_size; i++)
        new_plays[i] = filter->plays[i];
      for (i = min_size; i < new_size; i++)
        new_plays[i] = G_MAXUINT;

      g_free (filter->plays);
      filter->plays = new_plays;
      filter->max_plays = new_size;

      break;
    case PROP_TICK_RATE:
      filter->tick_rate = g_value_get_float (value);
      break;
    case PROP_TOTAL_TICKS:
      new_size = g_value_get_uint (value);
      min_size =
          (new_size < filter->total_ticks) ? new_size : filter->total_ticks;

      new_ticks = g_new (guint32, new_size / 32 + 1);
      for (i = 0; i <= min_size / 32; i++)
        new_ticks[i] = filter->ticks[i];
      for (i = min_size / 32 + 1; i <= new_size / 32; i++)
        new_ticks[i] = 0;

      g_free (filter->ticks);
      filter->ticks = new_ticks;
      filter->total_ticks = new_size;

      break;
    case PROP_TICKS:
      new_ticks = (guint *) g_value_get_pointer (value);
      if (new_ticks) {
        g_free (filter->ticks);
        filter->ticks = new_ticks;
      }
      break;
    default:
      break;
  }
}

static void
play_on_demand_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstPlayOnDemand *filter;

  g_return_if_fail (GST_IS_PLAYONDEMAND (object));
  filter = GST_PLAYONDEMAND (object);

  switch (prop_id) {
    case PROP_MUTE:
      g_value_set_boolean (value, filter->mute);
      break;
    case PROP_BUFFER_TIME:
      g_value_set_float (value, filter->buffer_time);
      break;
    case PROP_MAX_PLAYS:
      g_value_set_uint (value, filter->max_plays);
      break;
    case PROP_TICK_RATE:
      g_value_set_float (value, filter->tick_rate);
      break;
    case PROP_TOTAL_TICKS:
      g_value_set_uint (value, filter->total_ticks);
      break;
    case PROP_TICKS:
      g_value_set_pointer (value, (gpointer) filter->ticks);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
play_on_demand_dispose (GObject * object)
{
  GstPlayOnDemand *filter = GST_PLAYONDEMAND (object);

  G_OBJECT_CLASS (parent_class)->dispose (object);

  g_free (filter->ticks);
  g_free (filter->plays);
  g_free (filter->buffer);
}

static GstPadLinkReturn
play_on_demand_pad_link (GstPad * pad, const GstCaps * caps)
{
  const gchar *mimetype;
  GstPlayOnDemand *filter;
  GstStructure *structure;

  g_return_val_if_fail (caps != NULL, GST_PAD_LINK_DELAYED);
  g_return_val_if_fail (pad != NULL, GST_PAD_LINK_DELAYED);

  filter = GST_PLAYONDEMAND (GST_PAD_PARENT (pad));

  structure = gst_caps_get_structure (caps, 0);

  mimetype = gst_structure_get_name (structure);
  gst_structure_get_int (structure, "rate", &filter->rate);
  gst_structure_get_int (structure, "channels", &filter->channels);

  if (strcmp (mimetype, "audio/x-raw-int") == 0) {
    filter->format = GST_PLAYONDEMAND_FORMAT_INT;
    gst_structure_get_int (structure, "width", &filter->width);
  } else if (strcmp (mimetype, "audio/x-raw-float") == 0) {
    filter->format = GST_PLAYONDEMAND_FORMAT_FLOAT;
  }

  play_on_demand_resize_buffer (filter);

  return gst_pad_try_set_caps (filter->srcpad, caps);
}

inline static void
play_on_demand_add_play_pointer (GstPlayOnDemand * filter, guint pos)
{
  register guint i;

  if (filter->rate && ((filter->buffer_time * filter->rate) > pos)) {
    for (i = 0; i < filter->max_plays; i++) {
      if (filter->plays[i] == G_MAXUINT) {
        filter->plays[i] = pos;
        /* emit a signal to indicate a sample being played */
        g_signal_emit (filter, gst_pod_filter_signals[PLAYED_SIGNAL], 0);
        break;
      }
    }
  }
}

static void
play_on_demand_loop (GstElement * elem)
{
  GstPlayOnDemand *filter = GST_PLAYONDEMAND (elem);
  guint num_in, num_out, num_filter;
  GstData *in = NULL;
  GstBuffer *out = NULL;
  static guint last_tick = 0;

  g_return_if_fail (filter != NULL);
  g_return_if_fail (GST_IS_PLAYONDEMAND (filter));

  in = (in == NULL && !filter->eos) ? gst_pad_pull (filter->sinkpad) : NULL;

  if (filter->format == GST_PLAYONDEMAND_FORMAT_INT) {
    if (filter->width == 16) {
      gint16 min = 0xffff;
      gint16 max = 0x7fff;
      gint16 zero = 0;

#define _TYPE_ gint16
#include "filter.func"
#undef _TYPE_
    } else if (filter->width == 8) {
      gint8 min = 0xff;
      gint8 max = 0x7f;
      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_set_clock (GstElement * elem, GstClock * clock)
{
  GstPlayOnDemand *filter;

  g_return_if_fail (elem != NULL);
  g_return_if_fail (GST_IS_PLAYONDEMAND (elem));
  filter = GST_PLAYONDEMAND (elem);

  filter->clock = clock;
}

static void
play_on_demand_play_handler (GstElement * elem)
{
  GstPlayOnDemand *filter;

  g_return_if_fail (elem != NULL);
  g_return_if_fail (GST_IS_PLAYONDEMAND (elem));
  filter = GST_PLAYONDEMAND (elem);

  play_on_demand_add_play_pointer (filter, 0);
}

static void
play_on_demand_clear_handler (GstElement * elem)
{
  GstPlayOnDemand *filter;
  register guint i;

  g_return_if_fail (elem != NULL);
  g_return_if_fail (GST_IS_PLAYONDEMAND (elem));
  filter = GST_PLAYONDEMAND (elem);

  filter->write = 0;
  filter->eos = FALSE;

  for (i = 0; i < filter->max_plays; i++)
    filter->plays[i] = G_MAXUINT;
  for (i = 0; i < filter->buffer_bytes; i++)
    filter->buffer[i] = (gchar) 0;
}

static void
play_on_demand_reset_handler (GstElement * elem)
{
  GstPlayOnDemand *filter;
  register guint i;

  play_on_demand_clear_handler (elem);

  g_return_if_fail (elem != NULL);
  g_return_if_fail (GST_IS_PLAYONDEMAND (elem));
  filter = GST_PLAYONDEMAND (elem);

  for (i = 0; i <= filter->total_ticks / 32; i++)
    filter->ticks[i] = 0;
}

static void
play_on_demand_resize_buffer (GstPlayOnDemand * filter)
{
  register guint i;
  guint new_size, min_size;
  gchar *new_buffer;

  /* use a default sample rate of 44100, 1 channel, 1 byte per sample if caps
     haven't been set yet */
  new_size = (guint) filter->buffer_time;
  new_size *= (filter->rate) ? filter->rate : 44100;
  new_size *= (filter->channels) ? filter->channels : 1;

  if (filter->format && filter->format == GST_PLAYONDEMAND_FORMAT_FLOAT)
    new_size *= sizeof (gfloat);
  else
    new_size *= (filter->width) ? filter->width / 8 : 1;

  min_size =
      (new_size < filter->buffer_bytes) ? new_size : filter->buffer_bytes;

  new_buffer = g_new (gchar, new_size);
  for (i = 0; i < min_size; i++)
    new_buffer[i] = filter->buffer[i];
  for (i = min_size; i < new_size; i++)
    new_buffer[i] = (gchar) 0;

  g_free (filter->buffer);
  filter->buffer = new_buffer;
  filter->buffer_bytes = new_size;
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  return gst_element_register (plugin, "playondemand",
      GST_RANK_NONE, GST_TYPE_PLAYONDEMAND);
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    "playondemand",
    "Plays a stream at specific times, or when it receives a signal",
    plugin_init, VERSION, "LGPL", GST_PACKAGE, GST_ORIGIN)