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.
 */


#include <string.h>
#include <gst/gst.h>
#include <gst/audio/audio.h>

#include "gstplayondemand.h"


/* 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_CLOCK_SPEED  1e-8  /* 0.1 sec/tick default */

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


/* element factory information */
static GstElementDetails play_on_demand_details = {
  "Play On Demand",
  "Filter/Audio/Effect",
  "LGPL",
  "Plays a stream at specific times, or when it receives a signal",
  VERSION,
  "Leif Morgan Johnson <leif@ambient.2y.net>",
  "(C) 2002",
};


static GstPadTemplate*
play_on_demand_sink_factory (void)
{
  static GstPadTemplate *template = NULL;

  if (!template) {
    template = gst_pad_template_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_pad_template_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;
}


/* GObject functionality */
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);

/* GStreamer functionality */
static GstBufferPool*   play_on_demand_get_bufferpool (GstPad *pad);
static GstPadLinkReturn play_on_demand_pad_link       (GstPad *pad, 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),
      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;
}


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

enum {
  PROP_0,
  PROP_MUTE,
  PROP_BUFFER_TIME,
  PROP_MAX_PLAYS,
  PROP_CLOCK_SPEED,
  PROP_TOTAL_TICKS,
  PROP_TICK_LIST,
};

static guint gst_pod_filter_signals[LAST_SIGNAL] = { 0 };

static GstElementClass *parent_class = NULL;

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[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;

  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_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_MAXUINT - 2, GST_POD_BUFFER_TIME, G_PARAM_READWRITE));

  g_object_class_install_property(G_OBJECT_CLASS(klass), PROP_MAX_PLAYS,
    g_param_spec_uint("plays", "Maximum simultaneous playback",
                      "Maximum allowed number of simultaneous plays from the buffer",
                      1, G_MAXUINT, GST_POD_MAX_PLAYS, G_PARAM_READWRITE));

  g_object_class_install_property(G_OBJECT_CLASS(klass), PROP_CLOCK_SPEED,
    g_param_spec_float("clock-speed", "Clock speed (ticks/second)",
                       "The relative speed of a musical tick",
                       0, G_MAXFLOAT, 1, G_PARAM_READWRITE));

  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 (only relevant for tick lists)",
                      1, G_MAXUINT, 1, G_PARAM_READWRITE));

  g_object_class_install_property(G_OBJECT_CLASS(klass), PROP_TICK_LIST,
    g_param_spec_pointer("tick-list", "List of ticks to play",
                         "A list of ticks (musical times) at which to play the sample",
			 G_PARAM_WRITABLE));
}

static void
play_on_demand_init (GstPlayOnDemand *filter)
{
  guint i;

  filter->srcpad = gst_pad_new_from_template(play_on_demand_src_factory(), "src");
  filter->sinkpad = gst_pad_new_from_template(play_on_demand_sink_factory(), "sink");

  gst_pad_set_bufferpool_function(filter->sinkpad, play_on_demand_get_bufferpool);
  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 properties */
  filter->mute        = FALSE;
  filter->buffer_time = GST_POD_BUFFER_TIME;
  filter->max_plays   = GST_POD_MAX_PLAYS;
  filter->clock_speed = GST_POD_CLOCK_SPEED;
  filter->total_ticks = 1;
  filter->tick_list   = NULL;

  /* internal buffer stuff */
  play_on_demand_resize_buffer(filter);
  filter->eos                 = FALSE;

  /* play pointers, stored as an array of buffer offsets */
  filter->write = 0;
  filter->plays  = g_new(guint, filter->max_plays);
  for (i = 0; i < filter->max_plays; i++)
    filter->plays[i] = G_MAXUINT;
}

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;

  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, if there are any. */
    for (i = 0; i < filter->max_plays; i++)
      if (filter->plays[i] > filter->buffer_bytes)
        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 < filter->max_plays; i++) new_plays[i] = G_MAXUINT;

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

    break;
  case PROP_CLOCK_SPEED:
    filter->clock_speed = g_value_get_float(value);
    break;
  case PROP_TOTAL_TICKS:
    filter->total_ticks = g_value_get_uint(value);
    break;
  case PROP_TICK_LIST:
    filter->tick_list = (GSList *) g_value_get_pointer(value);
    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_CLOCK_SPEED:
    g_value_set_float(value, filter->clock_speed);
    break;
  case PROP_TOTAL_TICKS:
    g_value_set_uint(value, filter->total_ticks);
    break;
  default:
    G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
    break;
  }
}

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 GstPadLinkReturn
play_on_demand_pad_link (GstPad *pad, GstCaps *caps)
{
  const gchar *format;
  GstPlayOnDemand *filter;

  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));

  gst_caps_get_string(caps, "format", &format);
  gst_caps_get_int(caps, "rate",     &filter->rate);
  gst_caps_get_int(caps, "channels", &filter->channels);

  if (strcmp(format, "int") == 0) {
    filter->format = GST_PLAYONDEMAND_FORMAT_INT;
    gst_caps_get_int (caps, "width", &filter->width);
  } else if (strcmp(format, "float") == 0) {
    filter->format = GST_PLAYONDEMAND_FORMAT_FLOAT;
  }

  play_on_demand_resize_buffer(filter);

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

/* clock check macros. in these macros,
   f  == filter
   t  == tick in question
   c  == current tick (from the clock)
   l  == last tick (last tick when clock was checked)
   dt == ticks between c and t */
#define GST_POD_SAMPLE_OFFSET(f, dt) \
  ((guint) (dt * (f)->rate / (f)->clock_speed))

/* play a sample if the tick in question came between the last time we checked
   the clock and the current clock time. only looks complicated because the last
   clock time could have been at the end of the total_ticks, so the clock might
   have wrapped around ... */
#define GST_POD_TICK_ELAPSED(t, c, l) \
  (((l < c) && (l < t) && (t < c)) || ((l > c) && ((l < t) || (t < c))))

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;

  /* variables for clock check. */
  static guint     last_tick = 0;
  GSList          *tick_list;
  guint            tick, current_tick;

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

  filter->bufpool = gst_pad_get_bufferpool(filter->srcpad);

  if (filter->bufpool == NULL) {
    filter->bufpool = gst_buffer_pool_get_default(GST_POD_BUFPOOL_SIZE,
                                                  GST_POD_BUFPOOL_NUM);
  }

  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_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;

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

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

static void
play_on_demand_reset_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);

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

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

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);
        return;
      }
}

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 < filter->buffer_bytes; i++) new_buffer[i] = 0;

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

static gboolean
plugin_init (GModule *module, GstPlugin *plugin)
{
  GstElementFactory *factory;

  factory = gst_element_factory_new("playondemand",
                                    GST_TYPE_PLAYONDEMAND,
                                    &play_on_demand_details);
  g_return_val_if_fail(factory != NULL, FALSE);

  gst_element_factory_add_pad_template(factory, play_on_demand_src_factory());
  gst_element_factory_add_pad_template(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
};