text: 
  /*
  linphone
  Copyright (C) 2014 Belledonne Communications SARL
  
  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version 2
  of the License, or (at your option) any later version.
  
  This program 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 General Public License for more details.
  
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
  
  #include "private.h"
  
  /**
   * Open a new source on this player.
   * @param obj the player
   * @param filename file to open.
   * @param cb a callback used to notify end of play.
   * @param user_data a user-data provided in the callback to help the application to retrieve its context.
   * @return 0 if successful, -1 otherwise
  **/
  int linphone_player_open(LinphonePlayer *obj, const char *filename, LinphonePlayerEofCallback cb, void *user_data){
  	obj->user_data=user_data;
  	obj->cb=cb;
  	return obj->open(obj,filename);
  }
  
  /**
   * Start a play operation. The player must have been open previously with linphone_player_open().
   * @param obj the player.
   * @return 0 if successful, -1 otherwise
  **/
  int linphone_player_start(LinphonePlayer *obj){
  	return obj->start(obj);
  }
  
  /**
   * Suspend a play operation. The player must have been started previously with linphone_player_start().
   * @param obj the player.
   * @return 0 if successful, -1 otherwise
  **/
  int linphone_player_pause(LinphonePlayer *obj){
  	return obj->pause(obj);
  }
  
  /**
   * Seek at a given position given in milliseconds. The player must be in the paused state.
   * @param obj the player.
   * @param time_ms the position to seek to.
   * @return 0 if successful, -1 otherwise
  **/
  int linphone_player_seek(LinphonePlayer *obj, int time_ms){
  	return obj->seek(obj,time_ms);
  }
  
  /**
   * Get the state of play operation.
   * @param obj the player.
   * @return the state of the player within MSPlayerClosed, MSPlayerStarted, MSPlayerPaused.
  **/
  MSPlayerState linphone_player_get_state(LinphonePlayer *obj){
  	return obj->get_state(obj);
  }
  
  /**
   * Get the duration of the media
   * @param obj the player
   * @return  The duration in milliseconds
   */
  int linphone_player_get_duration(LinphonePlayer *obj) {
  	return obj->get_duration(obj);
  }
  
  /**
   * Get the position of the playback
   * @param obj the player
   * @return Position of the playback in milliseconds
   */
  int linphone_player_get_current_position(LinphonePlayer *obj) {
  	return obj->get_position(obj);
  }
  
  /**
   * Close the player.
   * @param obj the player.
  **/
  void linphone_player_close(LinphonePlayer *obj){
  	obj->close(obj);
  }
  
  /**
   * @brief Destroy a player
   * @param obj The player
   */
  void linphone_player_destroy(LinphonePlayer *obj) {
  	if(obj->destroy) obj->destroy(obj);
  }
  
  void _linphone_player_destroy(LinphonePlayer *player) {
  	ms_free(player);
  }
  
  
  /*
   * Call player implementation below.
   */
  
  
  static bool_t call_player_check_state(LinphonePlayer *player, bool_t check_player){
  	LinphoneCall *call=(LinphoneCall*)player->impl;
  	if (call->state!=LinphoneCallStreamsRunning){
  		ms_warning("Call [%p]: in-call player not usable in state [%s]",call,linphone_call_state_to_string(call->state));
  		return FALSE;
  	}
  	if (call->audiostream==NULL) {
  		ms_error("call_player_check_state(): no audiostream.");
  		return FALSE;
  	}
  	if (check_player && call->audiostream->av_player.player==NULL){
  		ms_error("call_player_check_state(): no player.");
  		return FALSE;
  	}
  	return TRUE;
  }
  
  static void on_eof(void *user_data, MSFilter *f, unsigned int event_id, void *arg){
  	LinphonePlayer *player=(LinphonePlayer *)user_data;
  	if (player->cb) player->cb(player,player->user_data);
  }
  
  static int call_player_open(LinphonePlayer* player, const char *filename){
  	LinphoneCall *call=(LinphoneCall*)player->impl;
  	MSFilter *filter;
  	if (!call_player_check_state(player,FALSE)) return -1;
  	filter=audio_stream_open_remote_play(call->audiostream,filename);
  	if (!filter) return -1;
  	ms_filter_add_notify_callback(filter,&on_eof,player,FALSE);
  	return 0;
  }
  
  static int call_player_start(LinphonePlayer *player){
  	LinphoneCall *call=(LinphoneCall*)player->impl;
  	if (!call_player_check_state(player,TRUE)) return -1;
  	return ms_filter_call_method_noarg(call->audiostream->av_player.player,MS_PLAYER_START);
  }
  
  static int call_player_pause(LinphonePlayer *player){
  	LinphoneCall *call=(LinphoneCall*)player->impl;
  	if (!call_player_check_state(player,TRUE)) return -1;
  	return ms_filter_call_method_noarg(call->audiostream->av_player.player,MS_PLAYER_PAUSE);
  }
  
  static MSPlayerState call_player_get_state(LinphonePlayer *player){
  	LinphoneCall *call=(LinphoneCall*)player->impl;
  	MSPlayerState state=MSPlayerClosed;
  	if (!call_player_check_state(player,TRUE)) return MSPlayerClosed;
  	ms_filter_call_method(call->audiostream->av_player.player,MS_PLAYER_GET_STATE,&state);
  	return state;
  }
  
  static int call_player_seek(LinphonePlayer *player, int time_ms){
  	LinphoneCall *call=(LinphoneCall*)player->impl;
  	if (!call_player_check_state(player,TRUE)) return -1;
  	return ms_filter_call_method(call->audiostream->av_player.player,MS_PLAYER_SEEK_MS,&time_ms);
  }
  
  static void call_player_close(LinphonePlayer *player){
  	LinphoneCall *call=(LinphoneCall*)player->impl;
  	if (!call_player_check_state(player,TRUE)) return;
  	audio_stream_close_remote_play(call->audiostream);
  	
  }
  
  static void on_call_destroy(void *obj, belle_sip_object_t *call_being_destroyed){
  	_linphone_player_destroy(obj);
  }
  
  LinphonePlayer *linphone_call_build_player(LinphoneCall *call){
  	LinphonePlayer *obj=ms_new0(LinphonePlayer,1);
  	obj->open=call_player_open;
  	obj->close=call_player_close;
  	obj->start=call_player_start;
  	obj->seek=call_player_seek;
  	obj->pause=call_player_pause;
  	obj->get_state=call_player_get_state;
  	obj->impl=call;
  	belle_sip_object_weak_ref(call,on_call_destroy,obj);
  	return obj;
  }
  