gstreamer/gst-libs/gst/sdp/gstsdpmessage.c

/* GStreamer
 * Copyright (C) <2005,2006> Wim Taymans <wim@fluendo.com>
 *
 * 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.
 */
/*
 * Unless otherwise indicated, Source Code is licensed under MIT license.
 * See further explanation attached in License Statement (distributed in the file
 * LICENSE).
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/**
 * SECTION:gstsdpmessage
 * @short_description: Helper methods for dealing with SDP messages
 *
 * <refsect2>
 * <para>
 * The GstSDPMessage helper functions makes it easy to parse and create SDP
 * messages. 
 * </para>
 * </refsect2>
 *
 * Last reviewed on 2007-07-24 (0.10.14)
 */


#include <stdlib.h>
#include <string.h>

#include "gstsdpmessage.h"

/* FIXME, is currently allocated on the stack */
#define MAX_LINE_LEN	1024 * 16

#define FREE_STRING(field)      g_free ((field)); (field) = NULL;
#define FREE_ARRAY(field)       \
G_STMT_START {                  \
  if (field)                    \
    g_array_free (field, TRUE); \
  field = NULL;                 \
} G_STMT_END
#define REPLACE_STRING(field,val)       FREE_STRING(field);field=g_strdup (val);

#define INIT_ARRAY(field,type,init_func)  		\
G_STMT_START {                   			\
  if (field) {                   			\
    guint i;			 			\
    for(i=0; i<field->len; i++)				\
      init_func (&g_array_index(field, type, i));	\
    g_array_set_size (field,0); 			\
  }				 			\
  else                          			\
    field = g_array_new (FALSE, TRUE, sizeof(type));    \
} G_STMT_END

#define DEFINE_STRING_SETTER(field)                                     \
GstSDPResult gst_sdp_message_set_##field (GstSDPMessage *msg, const gchar *val) {      \
  g_free (msg->field);                                                  \
  msg->field = g_strdup (val);                                          \
  return GST_SDP_OK;                                                       \
}
#define DEFINE_STRING_GETTER(field)                                     \
const gchar* gst_sdp_message_get_##field (GstSDPMessage *msg) {                       \
  return msg->field;                                                    \
}

#define DEFINE_ARRAY_LEN(field)                                         \
gint gst_sdp_message_##field##_len (GstSDPMessage *msg) {                      \
  return ((msg)->field->len);                                           \
}
#define DEFINE_ARRAY_GETTER(method,field,type)                          \
type gst_sdp_message_get_##method (GstSDPMessage *msg, guint idx) {            \
  return g_array_index ((msg)->field, type, idx);                       \
}
#define DEFINE_ARRAY_P_GETTER(method,field,type)                        \
type * gst_sdp_message_get_##method (GstSDPMessage *msg, guint idx) {          \
  return &g_array_index ((msg)->field, type, idx);                      \
}
#define DEFINE_ARRAY_ADDER(method,field,type,dup_method)                \
GstSDPResult gst_sdp_message_add_##method (GstSDPMessage *msg, type val) {       \
  type v = dup_method(val);                                             \
  g_array_append_val((msg)->field, v);                                  \
  return GST_SDP_OK;                                                       \
}

static void
gst_sdp_origin_init (GstSDPOrigin * origin)
{
  FREE_STRING (origin->username);
  FREE_STRING (origin->sess_id);
  FREE_STRING (origin->sess_version);
  FREE_STRING (origin->nettype);
  FREE_STRING (origin->addrtype);
  FREE_STRING (origin->addr);
}

static void
gst_sdp_connection_init (GstSDPConnection * connection)
{
  FREE_STRING (connection->nettype);
  FREE_STRING (connection->addrtype);
  FREE_STRING (connection->address);
  connection->ttl = 0;
  connection->addr_number = 0;
}

static void
gst_sdp_bandwidth_init (GstSDPBandwidth * bandwidth)
{
  FREE_STRING (bandwidth->bwtype);
  bandwidth->bandwidth = 0;
}

static void
gst_sdp_time_init (GstSDPTime * time)
{
  FREE_STRING (time->start);
  FREE_STRING (time->stop);
  time->n_repeat = 0;
}

static void
gst_sdp_zone_init (GstSDPZone * zone)
{
  FREE_STRING (zone->time);
  FREE_STRING (zone->typed_time);
}

static void
gst_sdp_key_init (GstSDPKey * key)
{
  FREE_STRING (key->type);
  FREE_STRING (key->data);
}

static void
gst_sdp_attribute_init (GstSDPAttribute * attr)
{
  FREE_STRING (attr->key);
  FREE_STRING (attr->value);
}

/**
 * gst_sdp_message_new:
 * @msg: pointer to new #GstSDPMessage
 *
 * Allocate a new GstSDPMessage and store the result in @msg.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_new (GstSDPMessage ** msg)
{
  GstSDPMessage *newmsg;

  g_return_val_if_fail (msg != NULL, GST_SDP_EINVAL);

  newmsg = g_new0 (GstSDPMessage, 1);

  *msg = newmsg;

  return gst_sdp_message_init (newmsg);
}

/**
 * gst_sdp_message_init:
 * @msg: a #GstSDPMessage
 *
 * Initialize @msg so that its contents are as if it was freshly allocated
 * with gst_sdp_message_new(). This function is mostly used to initialize a message
 * allocated on the stack. gst_sdp_message_uninit() undoes this operation.
 *
 * When this function is invoked on newly allocated data (with malloc or on the
 * stack), its contents should be set to 0 before calling this function.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_init (GstSDPMessage * msg)
{
  g_return_val_if_fail (msg != NULL, GST_SDP_EINVAL);

  FREE_STRING (msg->version);
  gst_sdp_origin_init (&msg->origin);
  FREE_STRING (msg->session_name);
  FREE_STRING (msg->information);
  FREE_STRING (msg->uri);
  INIT_ARRAY (msg->emails, gchar *, g_free);
  INIT_ARRAY (msg->phones, gchar *, g_free);
  gst_sdp_connection_init (&msg->connection);
  INIT_ARRAY (msg->bandwidths, GstSDPBandwidth, gst_sdp_bandwidth_init);
  INIT_ARRAY (msg->times, GstSDPTime, gst_sdp_time_init);
  INIT_ARRAY (msg->zones, GstSDPZone, gst_sdp_zone_init);
  gst_sdp_key_init (&msg->key);
  INIT_ARRAY (msg->attributes, GstSDPAttribute, gst_sdp_attribute_init);
  INIT_ARRAY (msg->medias, GstSDPMedia, gst_sdp_media_uninit);

  return GST_SDP_OK;
}

/**
 * gst_sdp_message_uninit:
 * @msg: a #GstSDPMessage
 *
 * Free all resources allocated in @msg. @msg should not be used anymore after
 * this function. This function should be used when @msg was allocated on the
 * stack and initialized with gst_sdp_message_init().
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_uninit (GstSDPMessage * msg)
{
  g_return_val_if_fail (msg != NULL, GST_SDP_EINVAL);

  gst_sdp_message_init (msg);

  FREE_ARRAY (msg->emails);
  FREE_ARRAY (msg->phones);
  FREE_ARRAY (msg->bandwidths);
  FREE_ARRAY (msg->times);
  FREE_ARRAY (msg->zones);
  FREE_ARRAY (msg->attributes);
  FREE_ARRAY (msg->medias);

  return GST_SDP_OK;
}

/**
 * gst_sdp_message_free:
 * @msg: a #GstSDPMessage
 *
 * Free all resources allocated by @msg. @msg should not be used anymore after
 * this function. This function should be used when @msg was dynamically
 * allocated with gst_sdp_message_new().
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_free (GstSDPMessage * msg)
{
  g_return_val_if_fail (msg != NULL, GST_SDP_EINVAL);

  gst_sdp_message_uninit (msg);
  g_free (msg);

  return GST_SDP_OK;
}

/**
 * gst_sdp_message_set_version:
 * @msg: a #GstSDPMessage
 * @version: the version
 *
 * Set the version in @msg.
 *
 * Returns: a #GstSDPResult.
 */
DEFINE_STRING_SETTER (version);
/**
 * gst_sdp_message_get_version:
 * @msg: a #GstSDPMessage
 *
 * Get the version in @msg.
 *
 * Returns: a #GstSDPResult.
 */
DEFINE_STRING_GETTER (version);

/**
 * gst_sdp_message_set_origin:
 * @msg: a #GstSDPMessage
 * @username: the user name
 * @sess_id: a session id
 * @sess_version: a session version
 * @nettype: a network type
 * @addrtype: an address type
 * @addr: an address
 *
 * Configure the SDP origin in @msg with the given parameters.
 *
 * Returns: #GST_SDP_OK.
 */
GstSDPResult
gst_sdp_message_set_origin (GstSDPMessage * msg, const gchar * username,
    const gchar * sess_id, const gchar * sess_version, const gchar * nettype,
    const gchar * addrtype, const gchar * addr)
{
  REPLACE_STRING (msg->origin.username, username);
  REPLACE_STRING (msg->origin.sess_id, sess_id);
  REPLACE_STRING (msg->origin.sess_version, sess_version);
  REPLACE_STRING (msg->origin.nettype, nettype);
  REPLACE_STRING (msg->origin.addrtype, addrtype);
  REPLACE_STRING (msg->origin.addr, addr);

  return GST_SDP_OK;
}

/**
 * gst_sdp_message_get_origin:
 * @msg: a #GstSDPMessage
 *
 * Get the origin of @msg.
 *
 * Returns: a #GstSDPOrigin. The result remains valid as long as @msg is valid.
 */
const GstSDPOrigin *
gst_sdp_message_get_origin (GstSDPMessage * msg)
{
  return &msg->origin;
}

/**
 * gst_sdp_message_set_session_name:
 * @msg: a #GstSDPMessage
 * @session_name: the session name
 *
 * Set the session name in @msg.
 *
 * Returns: a #GstSDPResult.
 */
DEFINE_STRING_SETTER (session_name);
/**
 * gst_sdp_message_get_session_name:
 * @msg: a #GstSDPMessage
 *
 * Get the session name in @msg.
 *
 * Returns: a #GstSDPResult.
 */
DEFINE_STRING_GETTER (session_name);
/**
 * gst_sdp_message_set_information:
 * @msg: a #GstSDPMessage
 * @information: the information
 *
 * Set the information in @msg.
 *
 * Returns: a #GstSDPResult.
 */
DEFINE_STRING_SETTER (information);
/**
 * gst_sdp_message_get_information:
 * @msg: a #GstSDPMessage
 *
 * Get the information in @msg.
 *
 * Returns: a #GstSDPResult.
 */
DEFINE_STRING_GETTER (information);
/**
 * gst_sdp_message_set_uri:
 * @msg: a #GstSDPMessage
 * @uri: the URI
 *
 * Set the URI in @msg.
 *
 * Returns: a #GstSDPResult.
 */
DEFINE_STRING_SETTER (uri);
/**
 * gst_sdp_message_get_uri:
 * @msg: a #GstSDPMessage
 *
 * Get the URI in @msg.
 *
 * Returns: a #GstSDPResult.
 */
DEFINE_STRING_GETTER (uri);

/**
 * gst_sdp_message_emails_len:
 * @msg: a #GstSDPMessage
 *
 * Get the number of emails in @msg.
 *
 * Returns: the number of emails in @msg.
 */
DEFINE_ARRAY_LEN (emails);
/**
 * gst_sdp_message_get_email:
 * @msg: a #GstSDPMessage
 * @idx: an email index
 *
 * Get the email with number @idx from @msg.
 *
 * Returns: the email at position @idx. 
 */
DEFINE_ARRAY_GETTER (email, emails, const gchar *);

/**
 * gst_sdp_message_add_email:
 * @msg: a #GstSDPMessage
 * @email: an email
 *
 * Add @email to the list of emails in @msg.
 *
 * Returns: a #GstSDPResult.
 */
DEFINE_ARRAY_ADDER (email, emails, const gchar *, g_strdup);

/**
 * gst_sdp_message_phones_len:
 * @msg: a #GstSDPMessage
 *
 * Get the number of phones in @msg.
 *
 * Returns: the number of phones in @msg.
 */
DEFINE_ARRAY_LEN (phones);
/**
 * gst_sdp_message_get_phone:
 * @msg: a #GstSDPMessage
 * @idx: a phone index
 *
 * Get the phone with number @idx from @msg.
 *
 * Returns: the phone at position @idx. 
 */
DEFINE_ARRAY_GETTER (phone, phones, const gchar *);

/**
 * gst_sdp_message_add_phone:
 * @msg: a #GstSDPMessage
 * @phone: a phone
 *
 * Add @phone to the list of phones in @msg.
 *
 * Returns: a #GstSDPResult.
 */
DEFINE_ARRAY_ADDER (phone, phones, const gchar *, g_strdup);

/**
 * gst_sdp_message_set_connection:
 * @msg: a #GstSDPMessage
 * @nettype: the type of network. "IN" is defined to have the meaning
 * "Internet".
 * @addrtype: the type of address.
 * @address: the address
 * @ttl: the time to live of the address
 * @addr_number: the number of layers
 *
 * Configure the SDP connection in @msg with the given parameters.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_set_connection (GstSDPMessage * msg, const gchar * nettype,
    const gchar * addrtype, const gchar * address, gint ttl, gint addr_number)
{
  REPLACE_STRING (msg->connection.nettype, nettype);
  REPLACE_STRING (msg->connection.addrtype, addrtype);
  REPLACE_STRING (msg->connection.address, address);
  msg->connection.ttl = ttl;
  msg->connection.addr_number = addr_number;

  return GST_SDP_OK;
}

/**
 * gst_sdp_message_get_connection:
 * @msg: a #GstSDPMessage
 *
 * Get the connection of @msg.
 *
 * Returns: a #GstSDPConnection. The result remains valid as long as @msg is valid.
 */
const GstSDPConnection *
gst_sdp_message_get_connection (GstSDPMessage * msg)
{
  return &msg->connection;
}

/**
 * gst_sdp_message_bandwidths_len:
 * @msg: a #GstSDPMessage
 *
 * Get the number of bandwidth information in @msg.
 *
 * Returns: the number of bandwidth information in @msg.
 */
DEFINE_ARRAY_LEN (bandwidths);
/**
 * gst_sdp_message_get_bandwidth:
 * @msg: a #GstSDPMessage
 * @idx: the bandwidth index
 *
 * Get the bandwidth at index @idx from @msg.
 *
 * Returns: a #GstSDPBandwidth.
 */
DEFINE_ARRAY_P_GETTER (bandwidth, bandwidths, const GstSDPBandwidth);

/**
 * gst_sdp_message_add_bandwidth:
 * @msg: a #GstSDPMessage
 * @bwtype: the bandwidth modifier type 
 * @bandwidth: the bandwidth in kilobits per second
 *
 * Add the specified bandwidth information to @msg.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_add_bandwidth (GstSDPMessage * msg, const gchar * bwtype,
    gint bandwidth)
{
  GstSDPBandwidth bw;

  bw.bwtype = g_strdup (bwtype);
  bw.bandwidth = bandwidth;

  g_array_append_val (msg->bandwidths, bw);

  return GST_SDP_OK;
}

/**
 * gst_sdp_message_times_len:
 * @msg: a #GstSDPMessage
 *
 * Get the number of time information entries in @msg.
 *
 * Returns: the number of time information entries in @msg.
 */
DEFINE_ARRAY_LEN (times);

/**
 * gst_sdp_message_get_time:
 * @msg: a #GstSDPMessage
 * @idx: the time index
 *
 * Get time information with index @idx from @msg.
 *
 * Returns: a #GstSDPTime.
 */
DEFINE_ARRAY_P_GETTER (time, times, const GstSDPTime);

/**
 * gst_sdp_message_add_time:
 * @msg: a #GstSDPMessage
 * @time: a time information
 *
 * Add time information @time to @msg.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_add_time (GstSDPMessage * msg, const gchar * time)
{
  return GST_SDP_OK;
}

/**
 * gst_sdp_message_zones_len:
 * @msg: a #GstSDPMessage
 *
 * Get the number of time zone information entries in @msg.
 *
 * Returns: the number of time zone information entries in @msg.
 */
DEFINE_ARRAY_LEN (zones);
/**
 * gst_sdp_message_get_zone:
 * @msg: a #GstSDPMessage
 * @idx: the zone index
 *
 * Get time zone information with index @idx from @msg.
 *
 * Returns: a #GstSDPZone.
 */
DEFINE_ARRAY_P_GETTER (zone, zones, const GstSDPZone);

/**
 * gst_sdp_message_add_zone:
 * @msg: a #GstSDPMessage
 * @time: the NTP time that a time zone adjustment happens
 * @typed_time: the offset from the time when the session was first scheduled 
 *
 * Add time zone information to @msg.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_add_zone (GstSDPMessage * msg, const gchar * time,
    const gchar * typed_time)
{
  GstSDPZone zone;

  zone.time = g_strdup (time);
  zone.typed_time = g_strdup (typed_time);

  g_array_append_val (msg->zones, zone);

  return GST_SDP_OK;
}

/**
 * gst_sdp_message_set_key:
 * @msg: a #GstSDPMessage
 * @type: the encryption type
 * @data: the encryption data
 *
 * Adds the encryption information to @msg.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_set_key (GstSDPMessage * msg, const gchar * type,
    const gchar * data)
{
  REPLACE_STRING (msg->key.type, type);
  REPLACE_STRING (msg->key.data, data);

  return GST_SDP_OK;
}

/**
 * gst_sdp_message_get_key:
 * @msg: a #GstSDPMessage
 *
 * Get the encryption information from @msg.
 *
 * Returns: a #GstSDPKey.
 */
const GstSDPKey *
gst_sdp_message_get_key (GstSDPMessage * msg)
{
  return &msg->key;
}

/**
 * gst_sdp_message_attributes_len:
 * @msg: a #GstSDPMessage
 *
 * Get the number of attributes in @msg.
 *
 * Returns: the number of attributes in @msg.
 */
DEFINE_ARRAY_LEN (attributes);
/**
 * gst_sdp_message_get_attribute:
 * @msg: a #GstSDPMessage
 * @idx: the index
 *
 * Get the attribute at position @idx in @msg.
 *
 * Returns: the #GstSDPAttribute at position @idx.
 */
DEFINE_ARRAY_P_GETTER (attribute, attributes, const GstSDPAttribute);
/**
 * gst_sdp_message_get_attribute_val_n:
 * @msg: a #GstSDPMessage
 * @key: the key
 * @nth: the index
 *
 * Get the @nth attribute with key @key in @msg.
 *
 * Returns: the attribute value of the @nth attribute with @key.
 */
const gchar *
gst_sdp_message_get_attribute_val_n (GstSDPMessage * msg, const gchar * key,
    guint nth)
{
  guint i;

  for (i = 0; i < msg->attributes->len; i++) {
    GstSDPAttribute *attr;

    attr = &g_array_index (msg->attributes, GstSDPAttribute, i);
    if (!strcmp (attr->key, key)) {
      if (nth == 0)
        return attr->value;
      else
        nth--;
    }
  }
  return NULL;
}

/**
 * gst_sdp_message_get_attribute_val:
 * @msg: a #GstSDPMessage
 * @key: the key
 *
 * Get the first attribute with key @key in @msg.
 *
 * Returns: the attribute value of the first attribute with @key.
 */
const gchar *
gst_sdp_message_get_attribute_val (GstSDPMessage * msg, const gchar * key)
{
  return gst_sdp_message_get_attribute_val_n (msg, key, 0);
}

/**
 * gst_sdp_message_add_attribute:
 * @msg: a #GstSDPMessage
 * @key: the key
 * @value: the value
 *
 * Add the attribute with @key and @value to @msg.
 *
 * Returns: @GST_SDP_OK.
 */
GstSDPResult
gst_sdp_message_add_attribute (GstSDPMessage * msg, const gchar * key,
    const gchar * value)
{
  GstSDPAttribute attr;

  attr.key = g_strdup (key);
  attr.value = g_strdup (value);

  g_array_append_val (msg->attributes, attr);

  return GST_SDP_OK;
}

/**
 * gst_sdp_message_medias_len:
 * @msg: a #GstSDPMessage
 *
 * Get the number of media descriptions in @msg.
 *
 * Returns: the number of media descriptions in @msg.
 */
DEFINE_ARRAY_LEN (medias);
/**
 * gst_sdp_message_get_media:
 * @msg: a #GstSDPMessage
 * @idx: the index
 *
 * Get the media description at index @idx in @msg.
 *
 * Returns: a #GstSDPMedia.
 */
DEFINE_ARRAY_P_GETTER (media, medias, const GstSDPMedia);

/**
 * gst_sdp_message_add_media:
 * @msg: a #GstSDPMessage
 * @media: a #GstSDPMedia to add
 *
 * Adds @media to the array of medias in @msg. This function takes ownership of
 * the contents of @media so that @media will have to be reinitialized with
 * gst_media_init() before it can be used again.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_add_media (GstSDPMessage * msg, GstSDPMedia * media)
{
  gint len;
  GstSDPMedia *nmedia;

  len = msg->medias->len;
  g_array_set_size (msg->medias, len + 1);
  nmedia = &g_array_index (msg->medias, GstSDPMedia, len);

  memcpy (nmedia, media, sizeof (GstSDPMedia));
  memset (media, 0, sizeof (GstSDPMedia));

  return GST_SDP_OK;
}

/* media access */

/**
 * gst_sdp_media_new:
 * @media: pointer to new #GstSDPMedia
 *
 * Allocate a new GstSDPMedia and store the result in @media.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_media_new (GstSDPMedia ** media)
{
  GstSDPMedia *newmedia;

  g_return_val_if_fail (media != NULL, GST_SDP_EINVAL);

  newmedia = g_new0 (GstSDPMedia, 1);

  *media = newmedia;

  return gst_sdp_media_init (newmedia);
}

/**
 * gst_sdp_media_init:
 * @media: a #GstSDPMedia
 *
 * Initialize @media so that its contents are as if it was freshly allocated
 * with gst_sdp_media_new(). This function is mostly used to initialize a media
 * allocated on the stack. gst_sdp_media_uninit() undoes this operation.
 *
 * When this function is invoked on newly allocated data (with malloc or on the
 * stack), its contents should be set to 0 before calling this function.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_media_init (GstSDPMedia * media)
{
  g_return_val_if_fail (media != NULL, GST_SDP_EINVAL);

  FREE_STRING (media->media);
  media->port = 0;
  media->num_ports = 0;
  FREE_STRING (media->proto);
  INIT_ARRAY (media->fmts, gchar *, g_free);
  FREE_STRING (media->information);
  INIT_ARRAY (media->connections, GstSDPConnection, gst_sdp_connection_init);
  INIT_ARRAY (media->bandwidths, GstSDPBandwidth, gst_sdp_bandwidth_init);
  gst_sdp_key_init (&media->key);
  INIT_ARRAY (media->attributes, GstSDPAttribute, gst_sdp_attribute_init);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_uninit:
 * @media: a #GstSDPMedia
 *
 * Free all resources allocated in @media. @media should not be used anymore after
 * this function. This function should be used when @media was allocated on the
 * stack and initialized with gst_sdp_media_init().
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_media_uninit (GstSDPMedia * media)
{
  g_return_val_if_fail (media != NULL, GST_SDP_EINVAL);

  gst_sdp_media_init (media);
  FREE_ARRAY (media->fmts);
  FREE_ARRAY (media->connections);
  FREE_ARRAY (media->bandwidths);
  FREE_ARRAY (media->attributes);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_free:
 * @media: a #GstSDPMedia
 *
 * Free all resources allocated by @media. @media should not be used anymore after
 * this function. This function should be used when @media was dynamically
 * allocated with gst_sdp_media_new().
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_media_free (GstSDPMedia * media)
{
  g_return_val_if_fail (media != NULL, GST_SDP_EINVAL);

  gst_sdp_media_uninit (media);
  g_free (media);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_get_media:
 * @media: a #GstSDPMedia
 *
 * Get the media description of @media.
 *
 * Returns: the media description.
 */
const gchar *
gst_sdp_media_get_media (const GstSDPMedia * media)
{
  return media->media;
}

/**
 * gst_sdp_media_set_media:
 * @media: a #GstSDPMedia
 * @med: the media description
 *
 * Set the media description of @media to @med.
 *
 * Returns: #GST_SDP_OK.
 */
GstSDPResult
gst_sdp_media_set_media (GstSDPMedia * media, const gchar * med)
{
  g_free (media->media);
  media->media = g_strdup (med);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_get_port:
 * @media: a #GstSDPMedia
 *
 * Get the port number for @media.
 *
 * Returns: the port number of @media.
 */
gint
gst_sdp_media_get_port (const GstSDPMedia * media)
{
  return media->port;
}

/**
 * gst_sdp_media_get_num_ports:
 * @media: a #GstSDPMedia
 *
 * Get the number of ports for @media.
 *
 * Returns: the number of ports for @media.
 */
gint
gst_sdp_media_get_num_ports (const GstSDPMedia * media)
{
  return media->num_ports;
}

/**
 * gst_sdp_media_set_port_info:
 * @media: a #GstSDPMedia
 * @port: the port number
 * @num_ports: the number of ports
 *
 * Set the port information in @media.
 *
 * Returns: #GST_SDP_OK.
 */
GstSDPResult
gst_sdp_media_set_port_info (GstSDPMedia * media, gint port, gint num_ports)
{
  media->port = port;
  media->num_ports = num_ports;

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_get_proto:
 * @media: a #GstSDPMedia
 *
 * Get the transport protocol of @media
 *
 * Returns: the transport protocol of @media.
 */
const gchar *
gst_sdp_media_get_proto (const GstSDPMedia * media)
{
  return media->proto;
}

/**
 * gst_sdp_media_set_proto:
 * @media: a #GstSDPMedia
 * @proto: the media transport protocol
 *
 * Set the media transport protocol of @media to @proto.
 *
 * Returns: #GST_SDP_OK.
 */
GstSDPResult
gst_sdp_media_set_proto (GstSDPMedia * media, const gchar * proto)
{
  g_free (media->proto);
  media->proto = g_strdup (proto);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_formats_len:
 * @media: a #GstSDPMedia
 *
 * Get the number of formats in @media.
 *
 * Returns: the number of formats in @media.
 */
gint
gst_sdp_media_formats_len (const GstSDPMedia * media)
{
  return media->fmts->len;
}

/**
 * gst_sdp_media_get_format:
 * @media: a #GstSDPMedia
 * @idx: an index
 *
 * Get the format information at position @idx in @media.
 *
 * Returns: the format at position @idx.
 */
const gchar *
gst_sdp_media_get_format (const GstSDPMedia * media, guint idx)
{
  if (idx >= media->fmts->len)
    return NULL;
  return g_array_index (media->fmts, gchar *, idx);
}

/**
 * gst_sdp_media_add_format:
 * @media: a #GstSDPMedia
 * @format: the format
 *
 * Add the format information to @media.
 *
 * Returns: #GST_SDP_OK.
 */
GstSDPResult
gst_sdp_media_add_format (GstSDPMedia * media, const gchar * format)
{
  gchar *fmt;

  fmt = g_strdup (format);

  g_array_append_val (media->fmts, fmt);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_get_information:
 * @media: a #GstSDPMedia
 *
 * Get the information of @media
 *
 * Returns: the information of @media.
 */
const gchar *
gst_sdp_media_get_information (const GstSDPMedia * media)
{
  return media->information;
}

/**
 * gst_sdp_media_set_information:
 * @media: a #GstSDPMedia
 * @information: the media information
 *
 * Set the media information of @media to @information.
 *
 * Returns: #GST_SDP_OK.
 */
GstSDPResult
gst_sdp_media_set_information (GstSDPMedia * media, const gchar * information)
{
  g_free (media->information);
  media->information = g_strdup (information);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_connections_len:
 * @media: a #GstSDPMedia
 *
 * Get the number of connection fields in @media.
 *
 * Returns: the number of connections in @media.
 */
gint
gst_sdp_media_connections_len (const GstSDPMedia * media)
{
  return (media->connections->len);
}

/**
 * gst_sdp_media_get_connection:
 * @media: a #GstSDPMedia
 * @idx: an index
 *
 * Get the connection at position @idx in @media.
 *
 * Returns: the #GstSDPConnection at position @idx.
 */
const GstSDPConnection *
gst_sdp_media_get_connection (const GstSDPMedia * media, guint idx)
{
  return &g_array_index (media->connections, GstSDPConnection, idx);
}

/**
 * gst_sdp_media_add_connection:
 * @media: a #GstSDPMedia
 * @nettype: the type of network. "IN" is defined to have the meaning
 * "Internet".
 * @addrtype: the type of address.
 * @address: the address
 * @ttl: the time to live of the address
 * @addr_number: the number of layers
 *
 * Add the given connection parameters to @media.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_media_add_connection (GstSDPMedia * media, const gchar * nettype,
    const gchar * addrtype, const gchar * address, gint ttl, gint addr_number)
{
  GstSDPConnection conn;

  conn.nettype = g_strdup (nettype);
  conn.addrtype = g_strdup (addrtype);
  conn.address = g_strdup (address);
  conn.ttl = ttl;
  conn.addr_number = addr_number;

  g_array_append_val (media->connections, conn);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_bandwidths_len:
 * @media: a #GstSDPMedia
 *
 * Get the number of bandwidth fields in @media.
 *
 * Returns: the number of bandwidths in @media.
 */
gint
gst_sdp_media_bandwidths_len (const GstSDPMedia * media)
{
  return (media->bandwidths->len);
}

/**
 * gst_sdp_media_get_bandwidth:
 * @media: a #GstSDPMedia
 * @idx: an index
 *
 * Get the bandwidth at position @idx in @media.
 *
 * Returns: the #GstSDPBandwidth at position @idx.
 */
const GstSDPBandwidth *
gst_sdp_media_get_badwidth (const GstSDPMedia * media, guint idx)
{
  return &g_array_index (media->bandwidths, GstSDPBandwidth, idx);
}

/**
 * gst_sdp_media_add_bandwidth:
 * @media: a #GstSDPMedia
 * @bwtype: the bandwidth modifier type
 * @bandwidth: the bandwidth in kilobits per second
 *
 * Add the bandwidth information with @bwtype and @bandwidth to @media.
 *
 * Returns: #GST_SDP_OK.
 */
GstSDPResult
gst_sdp_media_add_bandwidth (GstSDPMedia * media, const gchar * bwtype,
    gint bandwidth)
{
  GstSDPBandwidth bw;

  bw.bwtype = g_strdup (bwtype);
  bw.bandwidth = bandwidth;

  g_array_append_val (media->bandwidths, bw);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_set_key:
 * @media: a #GstSDPMedia
 * @type: the encryption type
 * @data: the encryption data
 *
 * Adds the encryption information to @media.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_media_set_key (GstSDPMedia * media, const gchar * type,
    const gchar * data)
{
  g_free (media->key.type);
  media->key.type = g_strdup (type);
  g_free (media->key.data);
  media->key.data = g_strdup (data);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_get_key:
 * @media: a #GstSDPMedia
 *
 * Get the encryption information from @media.
 *
 * Returns: a #GstSDPKey.
 */
const GstSDPKey *
gst_sdp_media_get_key (const GstSDPMedia * media)
{
  return &media->key;
}

/**
 * gst_sdp_media_attributes_len:
 * @media: a #GstSDPMedia
 *
 * Get the number of attribute fields in @media.
 *
 * Returns: the number of attributes in @media.
 */
gint
gst_sdp_media_attributes_len (const GstSDPMedia * media)
{
  return (media->attributes->len);
}

/**
 * gst_sdp_media_add_attribute:
 * @media: a #GstSDPMedia
 * @key: a key
 * @value: a value
 *
 * Add the attribute with @key and @value to @media.
 *
 * Returns: #GST_SDP_OK.
 */
GstSDPResult
gst_sdp_media_add_attribute (GstSDPMedia * media, const gchar * key,
    const gchar * value)
{
  GstSDPAttribute attr;

  attr.key = g_strdup (key);
  attr.value = g_strdup (value);

  g_array_append_val (media->attributes, attr);

  return GST_SDP_OK;
}

/**
 * gst_sdp_media_get_attribute:
 * @media: a #GstSDPMedia
 * @idx: an index
 *
 * Get the attribute at position @idx in @media.
 *
 * Returns: the #GstSDPAttribute at position @idx.
 */
const GstSDPAttribute *
gst_sdp_media_get_attribute (const GstSDPMedia * media, guint idx)
{
  return &g_array_index (media->attributes, GstSDPAttribute, idx);
}

/**
 * gst_sdp_media_get_attribute_val_n:
 * @media: a #GstSDPMedia
 * @key: a key
 * @nth: an index
 *
 * Get the @nth attribute value for @key in @media.
 *
 * Returns: the @nth attribute value.
 */
const gchar *
gst_sdp_media_get_attribute_val_n (const GstSDPMedia * media, const gchar * key,
    guint nth)
{
  guint i;

  for (i = 0; i < media->attributes->len; i++) {
    GstSDPAttribute *attr;

    attr = &g_array_index (media->attributes, GstSDPAttribute, i);
    if (!strcmp (attr->key, key)) {
      if (nth == 0)
        return attr->value;
      else
        nth--;
    }
  }
  return NULL;
}

/**
 * gst_sdp_media_get_attribute_val:
 * @media: a #GstSDPMedia
 * @key: a key
 *
 * Get the first attribute value for @key in @media.
 *
 * Returns: the first attribute value for @key.
 */
const gchar *
gst_sdp_media_get_attribute_val (const GstSDPMedia * media, const gchar * key)
{
  return gst_sdp_media_get_attribute_val_n (media, key, 0);
}

static void
read_string (gchar * dest, guint size, gchar ** src)
{
  guint idx;

  idx = 0;
  /* skip spaces */
  while (g_ascii_isspace (**src))
    (*src)++;

  while (!g_ascii_isspace (**src) && **src != '\0') {
    if (idx < size - 1)
      dest[idx++] = **src;
    (*src)++;
  }
  if (size > 0)
    dest[idx] = '\0';
}

static void
read_string_del (gchar * dest, guint size, gchar del, gchar ** src)
{
  guint idx;

  idx = 0;
  /* skip spaces */
  while (g_ascii_isspace (**src))
    (*src)++;

  while (**src != del && **src != '\0') {
    if (idx < size - 1)
      dest[idx++] = **src;
    (*src)++;
  }
  if (size > 0)
    dest[idx] = '\0';
}

enum
{
  SDP_SESSION,
  SDP_MEDIA,
};

typedef struct
{
  gint state;
  GstSDPMessage *msg;
  GstSDPMedia *media;
} SDPContext;

static gboolean
gst_sdp_parse_line (SDPContext * c, gchar type, gchar * buffer)
{
  gchar str[8192];
  gchar *p = buffer;

#define READ_STRING(field) read_string (str, sizeof(str), &p);REPLACE_STRING (field, str);
#define READ_INT(field) read_string (str, sizeof(str), &p);field = atoi(str);

  switch (type) {
    case 'v':
      if (buffer[0] != '0')
        g_warning ("wrong SDP version");
      gst_sdp_message_set_version (c->msg, buffer);
      break;
    case 'o':
      READ_STRING (c->msg->origin.username);
      READ_STRING (c->msg->origin.sess_id);
      READ_STRING (c->msg->origin.sess_version);
      READ_STRING (c->msg->origin.nettype);
      READ_STRING (c->msg->origin.addrtype);
      READ_STRING (c->msg->origin.addr);
      break;
    case 's':
      REPLACE_STRING (c->msg->session_name, buffer);
      break;
    case 'i':
      if (c->state == SDP_SESSION) {
        REPLACE_STRING (c->msg->information, buffer);
      } else {
        REPLACE_STRING (c->media->information, buffer);
      }
      break;
    case 'u':
      REPLACE_STRING (c->msg->uri, buffer);
      break;
    case 'e':
      gst_sdp_message_add_email (c->msg, buffer);
      break;
    case 'p':
      gst_sdp_message_add_phone (c->msg, buffer);
      break;
    case 'c':
      READ_STRING (c->msg->connection.nettype);
      READ_STRING (c->msg->connection.addrtype);
      READ_STRING (c->msg->connection.address);
      READ_INT (c->msg->connection.ttl);
      READ_INT (c->msg->connection.addr_number);
      break;
    case 'b':
    {
      gchar str2[MAX_LINE_LEN];

      read_string_del (str, sizeof (str), ':', &p);
      read_string (str2, sizeof (str2), &p);
      if (c->state == SDP_SESSION)
        gst_sdp_message_add_bandwidth (c->msg, str, atoi (str2));
      else
        gst_sdp_media_add_bandwidth (c->media, str, atoi (str2));
      break;
    }
    case 't':
      break;
    case 'k':

      break;
    case 'a':
      read_string_del (str, sizeof (str), ':', &p);
      if (*p != '\0')
        p++;
      if (c->state == SDP_SESSION)
        gst_sdp_message_add_attribute (c->msg, str, p);
      else
        gst_sdp_media_add_attribute (c->media, str, p);
      break;
    case 'm':
    {
      gchar *slash;
      GstSDPMedia nmedia;

      c->state = SDP_MEDIA;
      memset (&nmedia, 0, sizeof (nmedia));
      gst_sdp_media_init (&nmedia);

      READ_STRING (nmedia.media);
      read_string (str, sizeof (str), &p);
      slash = g_strrstr (str, "/");
      if (slash) {
        *slash = '\0';
        nmedia.port = atoi (str);
        nmedia.num_ports = atoi (slash + 1);
      } else {
        nmedia.port = atoi (str);
        nmedia.num_ports = -1;
      }
      READ_STRING (nmedia.proto);
      do {
        read_string (str, sizeof (str), &p);
        gst_sdp_media_add_format (&nmedia, str);
      } while (*p != '\0');

      gst_sdp_message_add_media (c->msg, &nmedia);
      c->media =
          &g_array_index (c->msg->medias, GstSDPMedia, c->msg->medias->len - 1);
      break;
    }
    default:
      break;
  }
  return TRUE;
}

/**
 * gst_sdp_message_parse_buffer:
 * @data: the start of the buffer
 * @size: the size of the buffer
 * @msg: the result #GstSDPMessage
 *
 * Parse the contents of @size bytes pointed to by @data and store the result in
 * @msg.
 *
 * Returns: #GST_SDP_OK on success.
 */
GstSDPResult
gst_sdp_message_parse_buffer (const guint8 * data, guint size,
    GstSDPMessage * msg)
{
  gchar *p;
  SDPContext c;
  gchar type;
  gchar buffer[MAX_LINE_LEN];
  guint idx = 0;

  g_return_val_if_fail (msg != NULL, GST_SDP_EINVAL);
  g_return_val_if_fail (data != NULL, GST_SDP_EINVAL);
  g_return_val_if_fail (size != 0, GST_SDP_EINVAL);

  c.state = SDP_SESSION;
  c.msg = msg;
  c.media = NULL;

  p = (gchar *) data;
  while (TRUE) {
    while (g_ascii_isspace (*p))
      p++;

    type = *p++;
    if (type == '\0')
      break;

    if (*p != '=')
      goto line_done;
    p++;

    idx = 0;
    while (*p != '\n' && *p != '\r' && *p != '\0') {
      if (idx < sizeof (buffer) - 1)
        buffer[idx++] = *p;
      p++;
    }
    buffer[idx] = '\0';
    gst_sdp_parse_line (&c, type, buffer);

  line_done:
    while (*p != '\n' && *p != '\0')
      p++;
    if (*p == '\n')
      p++;
  }

  return GST_SDP_OK;
}

static void
print_media (GstSDPMedia * media)
{
  g_print ("   media:       '%s'\n", media->media);
  g_print ("   port:        '%d'\n", media->port);
  g_print ("   num_ports:   '%d'\n", media->num_ports);
  g_print ("   proto:       '%s'\n", media->proto);
  if (media->fmts->len > 0) {
    guint i;

    g_print ("   formats:\n");
    for (i = 0; i < media->fmts->len; i++) {
      g_print ("    format  '%s'\n", g_array_index (media->fmts, gchar *, i));
    }
  }
  g_print ("   information: '%s'\n", media->information);
  g_print ("   key:\n");
  g_print ("    type:       '%s'\n", media->key.type);
  g_print ("    data:       '%s'\n", media->key.data);
  if (media->attributes->len > 0) {
    guint i;

    g_print ("   attributes:\n");
    for (i = 0; i < media->attributes->len; i++) {
      GstSDPAttribute *attr =
          &g_array_index (media->attributes, GstSDPAttribute, i);

      g_print ("    attribute '%s' : '%s'\n", attr->key, attr->value);
    }
  }
}

/**
 * gst_sdp_message_dump:
 * @msg: a #GstSDPMessage
 *
 * Dump the parsed contents of @msg to stdout.
 *
 * Returns: a #GstSDPResult.
 */
GstSDPResult
gst_sdp_message_dump (GstSDPMessage * msg)
{
  g_return_val_if_fail (msg != NULL, GST_SDP_EINVAL);

  g_print ("sdp packet %p:\n", msg);
  g_print (" version:       '%s'\n", msg->version);
  g_print (" origin:\n");
  g_print ("  username:     '%s'\n", msg->origin.username);
  g_print ("  sess_id:      '%s'\n", msg->origin.sess_id);
  g_print ("  sess_version: '%s'\n", msg->origin.sess_version);
  g_print ("  nettype:      '%s'\n", msg->origin.nettype);
  g_print ("  addrtype:     '%s'\n", msg->origin.addrtype);
  g_print ("  addr:         '%s'\n", msg->origin.addr);
  g_print (" session_name:  '%s'\n", msg->session_name);
  g_print (" information:   '%s'\n", msg->information);
  g_print (" uri:           '%s'\n", msg->uri);

  if (msg->emails->len > 0) {
    guint i;

    g_print (" emails:\n");
    for (i = 0; i < msg->emails->len; i++) {
      g_print ("  email '%s'\n", g_array_index (msg->emails, gchar *, i));
    }
  }
  if (msg->phones->len > 0) {
    guint i;

    g_print (" phones:\n");
    for (i = 0; i < msg->phones->len; i++) {
      g_print ("  phone '%s'\n", g_array_index (msg->phones, gchar *, i));
    }
  }
  g_print (" connection:\n");
  g_print ("  nettype:      '%s'\n", msg->connection.nettype);
  g_print ("  addrtype:     '%s'\n", msg->connection.addrtype);
  g_print ("  address:      '%s'\n", msg->connection.address);
  g_print ("  ttl:          '%d'\n", msg->connection.ttl);
  g_print ("  addr_number:  '%d'\n", msg->connection.addr_number);
  g_print (" key:\n");
  g_print ("  type:         '%s'\n", msg->key.type);
  g_print ("  data:         '%s'\n", msg->key.data);
  if (msg->attributes->len > 0) {
    guint i;

    g_print (" attributes:\n");
    for (i = 0; i < msg->attributes->len; i++) {
      GstSDPAttribute *attr =
          &g_array_index (msg->attributes, GstSDPAttribute, i);

      g_print ("  attribute '%s' : '%s'\n", attr->key, attr->value);
    }
  }
  if (msg->medias->len > 0) {
    guint i;

    g_print (" medias:\n");
    for (i = 0; i < msg->medias->len; i++) {
      g_print ("  media %d:\n", i);
      print_media (&g_array_index (msg->medias, GstSDPMedia, i));
    }
  }
  return GST_SDP_OK;
}