jni/pjproject-android/.svn/pristine/12/124eae0e21f410ad267ad93da413567e98b3c972.svn-base - jami-client-android - Gitiles

 /* $Id$ */
 /*
  * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
  * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
  *
  * 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 <pjmedia/sound_port.h>
 #include <pjmedia/alaw_ulaw.h>
 #include <pjmedia/delaybuf.h>
 #include <pjmedia/echo.h>
 #include <pjmedia/errno.h>
 #include <pj/assert.h>
 #include <pj/log.h>
 #include <pj/rand.h>
 #include <pj/string.h>	    /* pj_memset() */

 #define AEC_TAIL	    128	    /* default AEC length in ms */
 #define AEC_SUSPEND_LIMIT   5	    /* seconds of no activity	*/

 #define THIS_FILE	    "sound_port.c"

 //#define TEST_OVERFLOW_UNDERFLOW

 struct pjmedia_snd_port
 {
     int			 rec_id;
     int			 play_id;
     pj_uint32_t		 aud_caps;
     pjmedia_aud_param	 aud_param;
     pjmedia_aud_stream	*aud_stream;
     pjmedia_dir		 dir;
     pjmedia_port	*port;

     pjmedia_clock_src    cap_clocksrc,
                          play_clocksrc;

     unsigned		 clock_rate;
     unsigned		 channel_count;
     unsigned		 samples_per_frame;
     unsigned		 bits_per_sample;
     unsigned		 options;
     unsigned		 prm_ec_options;

     /* software ec */
     pjmedia_echo_state	*ec_state;
     unsigned		 ec_options;
     unsigned		 ec_tail_len;
     pj_bool_t		 ec_suspended;
     unsigned		 ec_suspend_count;
     unsigned		 ec_suspend_limit;
 };

 /*
  * The callback called by sound player when it needs more samples to be
  * played.
  */
 static pj_status_t play_cb(void *user_data, pjmedia_frame *frame)
 {
     pjmedia_snd_port *snd_port = (pjmedia_snd_port*) user_data;
     pjmedia_port *port;
     const unsigned required_size = (unsigned)frame->size;
     pj_status_t status;

     pjmedia_clock_src_update(&snd_port->play_clocksrc, &frame->timestamp);

     port = snd_port->port;
     if (port == NULL)
 	goto no_frame;

     status = pjmedia_port_get_frame(port, frame);
     if (status != PJ_SUCCESS)
 	goto no_frame;

     if (frame->type != PJMEDIA_FRAME_TYPE_AUDIO)
 	goto no_frame;

     /* Must supply the required samples */
     pj_assert(frame->size == required_size);

     if (snd_port->ec_state) {
 	if (snd_port->ec_suspended) {
 	    snd_port->ec_suspended = PJ_FALSE;
 	    //pjmedia_echo_state_reset(snd_port->ec_state);
 	    PJ_LOG(4,(THIS_FILE, "EC activated"));
 	}
 	snd_port->ec_suspend_count = 0;
 	pjmedia_echo_playback(snd_port->ec_state, (pj_int16_t*)frame->buf);
     }


     return PJ_SUCCESS;

 no_frame:
     frame->type = PJMEDIA_FRAME_TYPE_AUDIO;
     frame->size = required_size;
     pj_bzero(frame->buf, frame->size);

     if (snd_port->ec_state && !snd_port->ec_suspended) {
 	++snd_port->ec_suspend_count;
 	if (snd_port->ec_suspend_count > snd_port->ec_suspend_limit) {
 	    snd_port->ec_suspended = PJ_TRUE;
 	    PJ_LOG(4,(THIS_FILE, "EC suspended because of inactivity"));
 	}
 	if (snd_port->ec_state) {
 	    /* To maintain correct delay in EC */
 	    pjmedia_echo_playback(snd_port->ec_state, (pj_int16_t*)frame->buf);
 	}
     }

     return PJ_SUCCESS;
 }


 /*
  * The callback called by sound recorder when it has finished capturing a
  * frame.
  */
 static pj_status_t rec_cb(void *user_data, pjmedia_frame *frame)
 {
     pjmedia_snd_port *snd_port = (pjmedia_snd_port*) user_data;
     pjmedia_port *port;

     pjmedia_clock_src_update(&snd_port->cap_clocksrc, &frame->timestamp);

     port = snd_port->port;
     if (port == NULL)
 	return PJ_SUCCESS;

     /* Cancel echo */
     if (snd_port->ec_state && !snd_port->ec_suspended) {
 	pjmedia_echo_capture(snd_port->ec_state, (pj_int16_t*) frame->buf, 0);
     }

     pjmedia_port_put_frame(port, frame);


     return PJ_SUCCESS;
 }

 /*
  * The callback called by sound player when it needs more samples to be
  * played. This version is for non-PCM data.
  */
 static pj_status_t play_cb_ext(void *user_data, pjmedia_frame *frame)
 {
     pjmedia_snd_port *snd_port = (pjmedia_snd_port*) user_data;
     pjmedia_port *port = snd_port->port;

     if (port == NULL) {
 	frame->type = PJMEDIA_FRAME_TYPE_NONE;
 	return PJ_SUCCESS;
     }

     pjmedia_port_get_frame(port, frame);

     return PJ_SUCCESS;
 }


 /*
  * The callback called by sound recorder when it has finished capturing a
  * frame. This version is for non-PCM data.
  */
 static pj_status_t rec_cb_ext(void *user_data, pjmedia_frame *frame)
 {
     pjmedia_snd_port *snd_port = (pjmedia_snd_port*) user_data;
     pjmedia_port *port;

     port = snd_port->port;
     if (port == NULL)
 	return PJ_SUCCESS;

     pjmedia_port_put_frame(port, frame);

     return PJ_SUCCESS;
 }

 /* Initialize with default values (zero) */
 PJ_DEF(void) pjmedia_snd_port_param_default(pjmedia_snd_port_param *prm)
 {
     pj_bzero(prm, sizeof(*prm));
 }

 /*
  * Start the sound stream.
  * This may be called even when the sound stream has already been started.
  */
 static pj_status_t start_sound_device( pj_pool_t *pool,
 				       pjmedia_snd_port *snd_port )
 {
     pjmedia_aud_rec_cb snd_rec_cb;
     pjmedia_aud_play_cb snd_play_cb;
     pjmedia_aud_param param_copy;
     pj_status_t status;

     /* Check if sound has been started. */
     if (snd_port->aud_stream != NULL)
 	return PJ_SUCCESS;

     PJ_ASSERT_RETURN(snd_port->dir == PJMEDIA_DIR_CAPTURE ||
 		     snd_port->dir == PJMEDIA_DIR_PLAYBACK ||
 		     snd_port->dir == PJMEDIA_DIR_CAPTURE_PLAYBACK,
 		     PJ_EBUG);

     /* Get device caps */
     if (snd_port->aud_param.dir & PJMEDIA_DIR_CAPTURE) {
 	pjmedia_aud_dev_info dev_info;

 	status = pjmedia_aud_dev_get_info(snd_port->aud_param.rec_id,
 					  &dev_info);
 	if (status != PJ_SUCCESS)
 	    return status;

 	snd_port->aud_caps = dev_info.caps;
     } else {
 	snd_port->aud_caps = 0;
     }

     /* Process EC settings */
     pj_memcpy(&param_copy, &snd_port->aud_param, sizeof(param_copy));
     if (param_copy.flags & PJMEDIA_AUD_DEV_CAP_EC) {
 	/* EC is wanted */
 	if ((snd_port->prm_ec_options & PJMEDIA_ECHO_USE_SW_ECHO) == 0 &&
             (snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC))
         {
 	    /* Device supports EC */
 	    /* Nothing to do */
 	} else {
 	    /* Application wants to use software EC or device
              * doesn't support EC, remove EC settings from
 	     * device parameters
 	     */
 	    param_copy.flags &= ~(PJMEDIA_AUD_DEV_CAP_EC |
 				  PJMEDIA_AUD_DEV_CAP_EC_TAIL);
 	}
     }

     /* Use different callback if format is not PCM */
     if (snd_port->aud_param.ext_fmt.id == PJMEDIA_FORMAT_L16) {
 	snd_rec_cb = &rec_cb;
 	snd_play_cb = &play_cb;
     } else {
 	snd_rec_cb = &rec_cb_ext;
 	snd_play_cb = &play_cb_ext;
     }

     /* Open the device */
     status = pjmedia_aud_stream_create(&param_copy,
 				       snd_rec_cb,
 				       snd_play_cb,
 				       snd_port,
 				       &snd_port->aud_stream);

     if (status != PJ_SUCCESS)
 	return status;

     /* Inactivity limit before EC is suspended. */
     snd_port->ec_suspend_limit = AEC_SUSPEND_LIMIT *
 				 (snd_port->clock_rate /
 				  snd_port->samples_per_frame);

     /* Create software EC if parameter specifies EC and
      * (app specifically requests software EC or device
      * doesn't support EC). Only do this if the format is PCM!
      */
     if ((snd_port->aud_param.flags & PJMEDIA_AUD_DEV_CAP_EC) &&
 	((snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC)==0 ||
          (snd_port->prm_ec_options & PJMEDIA_ECHO_USE_SW_ECHO) != 0) &&
 	param_copy.ext_fmt.id == PJMEDIA_FORMAT_PCM)
     {
 	if ((snd_port->aud_param.flags & PJMEDIA_AUD_DEV_CAP_EC_TAIL)==0) {
 	    snd_port->aud_param.flags |= PJMEDIA_AUD_DEV_CAP_EC_TAIL;
 	    snd_port->aud_param.ec_tail_ms = AEC_TAIL;
 	    PJ_LOG(4,(THIS_FILE, "AEC tail is set to default %u ms",
 				 snd_port->aud_param.ec_tail_ms));
 	}

 	status = pjmedia_snd_port_set_ec(snd_port, pool,
 					 snd_port->aud_param.ec_tail_ms,
 					 snd_port->prm_ec_options);
 	if (status != PJ_SUCCESS) {
 	    pjmedia_aud_stream_destroy(snd_port->aud_stream);
 	    snd_port->aud_stream = NULL;
 	    return status;
 	}
     }

     /* Start sound stream. */
     if (!(snd_port->options & PJMEDIA_SND_PORT_NO_AUTO_START)) {
 	status = pjmedia_aud_stream_start(snd_port->aud_stream);
     }
     if (status != PJ_SUCCESS) {
 	pjmedia_aud_stream_destroy(snd_port->aud_stream);
 	snd_port->aud_stream = NULL;
 	return status;
     }

     return PJ_SUCCESS;
 }


 /*
  * Stop the sound device.
  * This may be called even when there's no sound device in the port.
  */
 static pj_status_t stop_sound_device( pjmedia_snd_port *snd_port )
 {
     /* Check if we have sound stream device. */
     if (snd_port->aud_stream) {
 	pjmedia_aud_stream_stop(snd_port->aud_stream);
 	pjmedia_aud_stream_destroy(snd_port->aud_stream);
 	snd_port->aud_stream = NULL;
     }

     /* Destroy AEC */
     if (snd_port->ec_state) {
 	pjmedia_echo_destroy(snd_port->ec_state);
 	snd_port->ec_state = NULL;
     }

     return PJ_SUCCESS;
 }


 /*
  * Create bidirectional port.
  */
 PJ_DEF(pj_status_t) pjmedia_snd_port_create( pj_pool_t *pool,
 					     int rec_id,
 					     int play_id,
 					     unsigned clock_rate,
 					     unsigned channel_count,
 					     unsigned samples_per_frame,
 					     unsigned bits_per_sample,
 					     unsigned options,
 					     pjmedia_snd_port **p_port)
 {
     pjmedia_snd_port_param param;
     pj_status_t status;

     pjmedia_snd_port_param_default(&param);

     status = pjmedia_aud_dev_default_param(rec_id, &param.base);
     if (status != PJ_SUCCESS)
 	return status;

     param.base.dir = PJMEDIA_DIR_CAPTURE_PLAYBACK;
     param.base.rec_id = rec_id;
     param.base.play_id = play_id;
     param.base.clock_rate = clock_rate;
     param.base.channel_count = channel_count;
     param.base.samples_per_frame = samples_per_frame;
     param.base.bits_per_sample = bits_per_sample;
     param.options = options;
     param.ec_options = 0;

     return pjmedia_snd_port_create2(pool, &param, p_port);
 }

 /*
  * Create sound recorder AEC.
  */
 PJ_DEF(pj_status_t) pjmedia_snd_port_create_rec( pj_pool_t *pool,
 						 int dev_id,
 						 unsigned clock_rate,
 						 unsigned channel_count,
 						 unsigned samples_per_frame,
 						 unsigned bits_per_sample,
 						 unsigned options,
 						 pjmedia_snd_port **p_port)
 {
     pjmedia_snd_port_param param;
     pj_status_t status;

     pjmedia_snd_port_param_default(&param);

     status = pjmedia_aud_dev_default_param(dev_id, &param.base);
     if (status != PJ_SUCCESS)
 	return status;

     param.base.dir = PJMEDIA_DIR_CAPTURE;
     param.base.rec_id = dev_id;
     param.base.clock_rate = clock_rate;
     param.base.channel_count = channel_count;
     param.base.samples_per_frame = samples_per_frame;
     param.base.bits_per_sample = bits_per_sample;
     param.options = options;
     param.ec_options = 0;

     return pjmedia_snd_port_create2(pool, &param, p_port);
 }


 /*
  * Create sound player port.
  */
 PJ_DEF(pj_status_t) pjmedia_snd_port_create_player( pj_pool_t *pool,
 						    int dev_id,
 						    unsigned clock_rate,
 						    unsigned channel_count,
 						    unsigned samples_per_frame,
 						    unsigned bits_per_sample,
 						    unsigned options,
 						    pjmedia_snd_port **p_port)
 {
     pjmedia_snd_port_param param;
     pj_status_t status;

     pjmedia_snd_port_param_default(&param);

     status = pjmedia_aud_dev_default_param(dev_id, &param.base);
     if (status != PJ_SUCCESS)
 	return status;

     param.base.dir = PJMEDIA_DIR_PLAYBACK;
     param.base.play_id = dev_id;
     param.base.clock_rate = clock_rate;
     param.base.channel_count = channel_count;
     param.base.samples_per_frame = samples_per_frame;
     param.base.bits_per_sample = bits_per_sample;
     param.options = options;
     param.ec_options = 0;

     return pjmedia_snd_port_create2(pool, &param, p_port);
 }


 /*
  * Create sound port.
  */
 PJ_DEF(pj_status_t) pjmedia_snd_port_create2(pj_pool_t *pool,
 					     const pjmedia_snd_port_param *prm,
 					     pjmedia_snd_port **p_port)
 {
     pjmedia_snd_port *snd_port;
     pj_status_t status;
     unsigned ptime_usec;

     PJ_ASSERT_RETURN(pool && prm && p_port, PJ_EINVAL);

     snd_port = PJ_POOL_ZALLOC_T(pool, pjmedia_snd_port);
     PJ_ASSERT_RETURN(snd_port, PJ_ENOMEM);

     snd_port->dir = prm->base.dir;
     snd_port->rec_id = prm->base.rec_id;
     snd_port->play_id = prm->base.play_id;
     snd_port->clock_rate = prm->base.clock_rate;
     snd_port->channel_count = prm->base.channel_count;
     snd_port->samples_per_frame = prm->base.samples_per_frame;
     snd_port->bits_per_sample = prm->base.bits_per_sample;
     pj_memcpy(&snd_port->aud_param, &prm->base, sizeof(snd_port->aud_param));
     snd_port->options = prm->options;
     snd_port->prm_ec_options = prm->ec_options;

     ptime_usec = prm->base.samples_per_frame * 1000 / prm->base.channel_count /
                  prm->base.clock_rate * 1000;
     pjmedia_clock_src_init(&snd_port->cap_clocksrc, PJMEDIA_TYPE_AUDIO,
                            snd_port->clock_rate, ptime_usec);
     pjmedia_clock_src_init(&snd_port->play_clocksrc, PJMEDIA_TYPE_AUDIO,
                            snd_port->clock_rate, ptime_usec);

     /* Start sound device immediately.
      * If there's no port connected, the sound callback will return
      * empty signal.
      */
     status = start_sound_device( pool, snd_port );
     if (status != PJ_SUCCESS) {
 	pjmedia_snd_port_destroy(snd_port);
 	return status;
     }

     *p_port = snd_port;
     return PJ_SUCCESS;
 }


 /*
  * Destroy port (also destroys the sound device).
  */
 PJ_DEF(pj_status_t) pjmedia_snd_port_destroy(pjmedia_snd_port *snd_port)
 {
     PJ_ASSERT_RETURN(snd_port, PJ_EINVAL);

     return stop_sound_device(snd_port);
 }


 /*
  * Retrieve the sound stream associated by this sound device port.
  */
 PJ_DEF(pjmedia_aud_stream*) pjmedia_snd_port_get_snd_stream(
 						pjmedia_snd_port *snd_port)
 {
     PJ_ASSERT_RETURN(snd_port, NULL);
     return snd_port->aud_stream;
 }


 /*
  * Change EC settings.
  */
 PJ_DEF(pj_status_t) pjmedia_snd_port_set_ec( pjmedia_snd_port *snd_port,
 					     pj_pool_t *pool,
 					     unsigned tail_ms,
 					     unsigned options)
 {
     pjmedia_aud_param prm;
     pj_status_t status;

     /* Sound must be opened in full-duplex mode */
     PJ_ASSERT_RETURN(snd_port &&
 		     snd_port->dir == PJMEDIA_DIR_CAPTURE_PLAYBACK,
 		     PJ_EINVALIDOP);

     /* Determine whether we use device or software EC */
     if ((snd_port->prm_ec_options & PJMEDIA_ECHO_USE_SW_ECHO) == 0 &&
         (snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC))
     {
 	/* We use device EC */
 	pj_bool_t ec_enabled;

 	/* Query EC status */
 	status = pjmedia_aud_stream_get_cap(snd_port->aud_stream,
 					    PJMEDIA_AUD_DEV_CAP_EC,
 					    &ec_enabled);
 	if (status != PJ_SUCCESS)
 	    return status;

 	if (tail_ms != 0) {
 	    /* Change EC setting */

 	    if (!ec_enabled) {
 		/* Enable EC first */
 		pj_bool_t value = PJ_TRUE;
 		status = pjmedia_aud_stream_set_cap(snd_port->aud_stream,
 						    PJMEDIA_AUD_DEV_CAP_EC,
 						    &value);
 		if (status != PJ_SUCCESS)
 		    return status;
 	    }

 	    if ((snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC_TAIL)==0) {
 		/* Device does not support setting EC tail */
 		return PJMEDIA_EAUD_INVCAP;
 	    }

 	    return pjmedia_aud_stream_set_cap(snd_port->aud_stream,
 					      PJMEDIA_AUD_DEV_CAP_EC_TAIL,
 					      &tail_ms);

 	} else if (ec_enabled) {
 	    /* Disable EC */
 	    pj_bool_t value = PJ_FALSE;
 	    return pjmedia_aud_stream_set_cap(snd_port->aud_stream,
 					      PJMEDIA_AUD_DEV_CAP_EC,
 					      &value);
 	} else {
 	    /* Request to disable EC but EC has been disabled */
 	    /* Do nothing */
 	    return PJ_SUCCESS;
 	}

     } else {
 	/* We use software EC */

 	/* Check if there is change in parameters */
 	if (tail_ms==snd_port->ec_tail_len && options==snd_port->ec_options) {
 	    PJ_LOG(5,(THIS_FILE, "pjmedia_snd_port_set_ec() ignored, no "
 				 "change in settings"));
 	    return PJ_SUCCESS;
 	}

 	status = pjmedia_aud_stream_get_param(snd_port->aud_stream, &prm);
 	if (status != PJ_SUCCESS)
 	    return status;

 	/* Audio stream must be in PCM format */
 	PJ_ASSERT_RETURN(prm.ext_fmt.id == PJMEDIA_FORMAT_PCM,
 			 PJ_EINVALIDOP);

 	/* Destroy AEC */
 	if (snd_port->ec_state) {
 	    pjmedia_echo_destroy(snd_port->ec_state);
 	    snd_port->ec_state = NULL;
 	}

 	if (tail_ms != 0) {
 	    unsigned delay_ms;

 	    //No need to add input latency in the latency calculation,
 	    //since actual input latency should be zero.
 	    //delay_ms = (si.rec_latency + si.play_latency) * 1000 /
 	    //	   snd_port->clock_rate;
 	    /* Set EC latency to 3/4 of output latency to reduce the
 	     * possibility of missing/late reference frame.
 	     */
 	    delay_ms = prm.output_latency_ms * 3/4;
 	    status = pjmedia_echo_create2(pool, snd_port->clock_rate,
 					  snd_port->channel_count,
 					  snd_port->samples_per_frame,
 					  tail_ms, delay_ms,
 					  options, &snd_port->ec_state);
 	    if (status != PJ_SUCCESS)
 		snd_port->ec_state = NULL;
 	    else
 		snd_port->ec_suspended = PJ_FALSE;
 	} else {
 	    PJ_LOG(4,(THIS_FILE, "Echo canceller is now disabled in the "
 				 "sound port"));
 	    status = PJ_SUCCESS;
 	}

 	snd_port->ec_options = options;
 	snd_port->ec_tail_len = tail_ms;
     }

     return status;
 }


 /* Get AEC tail length */
 PJ_DEF(pj_status_t) pjmedia_snd_port_get_ec_tail( pjmedia_snd_port *snd_port,
 						  unsigned *p_length)
 {
     PJ_ASSERT_RETURN(snd_port && p_length, PJ_EINVAL);

     /* Determine whether we use device or software EC */
     if (snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC) {
 	/* We use device EC */
 	pj_bool_t ec_enabled;
 	pj_status_t status;

 	/* Query EC status */
 	status = pjmedia_aud_stream_get_cap(snd_port->aud_stream,
 					    PJMEDIA_AUD_DEV_CAP_EC,
 					    &ec_enabled);
 	if (status != PJ_SUCCESS)
 	    return status;

 	if (!ec_enabled) {
 	    *p_length = 0;
 	} else if (snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC_TAIL) {
 	    /* Get device EC tail */
 	    status = pjmedia_aud_stream_get_cap(snd_port->aud_stream,
 						PJMEDIA_AUD_DEV_CAP_EC_TAIL,
 						p_length);
 	    if (status != PJ_SUCCESS)
 		return status;
 	} else {
 	    /* Just use default */
 	    *p_length = AEC_TAIL;
 	}

     } else {
 	/* We use software EC */
 	*p_length =  snd_port->ec_state ? snd_port->ec_tail_len : 0;
     }
     return PJ_SUCCESS;
 }


 /*
  * Get clock source.
  */
 PJ_DEF(pjmedia_clock_src *)
 pjmedia_snd_port_get_clock_src( pjmedia_snd_port *snd_port,
                                 pjmedia_dir dir )
 {
     return (dir == PJMEDIA_DIR_CAPTURE? &snd_port->cap_clocksrc:
             &snd_port->play_clocksrc);
 }


 /*
  * Connect a port.
  */
 PJ_DEF(pj_status_t) pjmedia_snd_port_connect( pjmedia_snd_port *snd_port,
 					      pjmedia_port *port)
 {
     pjmedia_audio_format_detail *afd;

     PJ_ASSERT_RETURN(snd_port && port, PJ_EINVAL);

     afd = pjmedia_format_get_audio_format_detail(&port->info.fmt, PJ_TRUE);

     /* Check that port has the same configuration as the sound device
      * port.
      */
     if (afd->clock_rate != snd_port->clock_rate)
 	return PJMEDIA_ENCCLOCKRATE;

     if (PJMEDIA_AFD_SPF(afd) != snd_port->samples_per_frame)
 	return PJMEDIA_ENCSAMPLESPFRAME;

     if (afd->channel_count != snd_port->channel_count)
 	return PJMEDIA_ENCCHANNEL;

     if (afd->bits_per_sample != snd_port->bits_per_sample)
 	return PJMEDIA_ENCBITS;

     /* Port is okay. */
     snd_port->port = port;
     return PJ_SUCCESS;
 }


 /*
  * Get the connected port.
  */
 PJ_DEF(pjmedia_port*) pjmedia_snd_port_get_port(pjmedia_snd_port *snd_port)
 {
     PJ_ASSERT_RETURN(snd_port, NULL);
     return snd_port->port;
 }


 /*
  * Disconnect port.
  */
 PJ_DEF(pj_status_t) pjmedia_snd_port_disconnect(pjmedia_snd_port *snd_port)
 {
     PJ_ASSERT_RETURN(snd_port, PJ_EINVAL);

     snd_port->port = NULL;

     return PJ_SUCCESS;
 }
	/* $Id$ */
	/*
	* Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
	* Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
	*
	* 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 <pjmedia/sound_port.h>
	#include <pjmedia/alaw_ulaw.h>
	#include <pjmedia/delaybuf.h>
	#include <pjmedia/echo.h>
	#include <pjmedia/errno.h>
	#include <pj/assert.h>
	#include <pj/log.h>
	#include <pj/rand.h>
	#include <pj/string.h> /* pj_memset() */

	#define AEC_TAIL 128 /* default AEC length in ms */
	#define AEC_SUSPEND_LIMIT 5 /* seconds of no activity */

	#define THIS_FILE "sound_port.c"

	//#define TEST_OVERFLOW_UNDERFLOW

	struct pjmedia_snd_port
	{
	int rec_id;
	int play_id;
	pj_uint32_t aud_caps;
	pjmedia_aud_param aud_param;
	pjmedia_aud_stream *aud_stream;
	pjmedia_dir dir;
	pjmedia_port *port;

	pjmedia_clock_src cap_clocksrc,
	play_clocksrc;

	unsigned clock_rate;
	unsigned channel_count;
	unsigned samples_per_frame;
	unsigned bits_per_sample;
	unsigned options;
	unsigned prm_ec_options;

	/* software ec */
	pjmedia_echo_state *ec_state;
	unsigned ec_options;
	unsigned ec_tail_len;
	pj_bool_t ec_suspended;
	unsigned ec_suspend_count;
	unsigned ec_suspend_limit;
	};

	/*
	* The callback called by sound player when it needs more samples to be
	* played.
	*/
	static pj_status_t play_cb(void user_data, pjmedia_frame frame)
	{
	pjmedia_snd_port snd_port = (pjmedia_snd_port) user_data;
	pjmedia_port *port;
	const unsigned required_size = (unsigned)frame->size;
	pj_status_t status;

	pjmedia_clock_src_update(&snd_port->play_clocksrc, &frame->timestamp);

	port = snd_port->port;
	if (port == NULL)
	goto no_frame;

	status = pjmedia_port_get_frame(port, frame);
	if (status != PJ_SUCCESS)
	goto no_frame;

	if (frame->type != PJMEDIA_FRAME_TYPE_AUDIO)
	goto no_frame;

	/* Must supply the required samples */
	pj_assert(frame->size == required_size);

	if (snd_port->ec_state) {
	if (snd_port->ec_suspended) {
	snd_port->ec_suspended = PJ_FALSE;
	//pjmedia_echo_state_reset(snd_port->ec_state);
	PJ_LOG(4,(THIS_FILE, "EC activated"));
	}
	snd_port->ec_suspend_count = 0;
	pjmedia_echo_playback(snd_port->ec_state, (pj_int16_t*)frame->buf);
	}


	return PJ_SUCCESS;

	no_frame:
	frame->type = PJMEDIA_FRAME_TYPE_AUDIO;
	frame->size = required_size;
	pj_bzero(frame->buf, frame->size);

	if (snd_port->ec_state && !snd_port->ec_suspended) {
	++snd_port->ec_suspend_count;
	if (snd_port->ec_suspend_count > snd_port->ec_suspend_limit) {
	snd_port->ec_suspended = PJ_TRUE;
	PJ_LOG(4,(THIS_FILE, "EC suspended because of inactivity"));
	}
	if (snd_port->ec_state) {
	/* To maintain correct delay in EC */
	pjmedia_echo_playback(snd_port->ec_state, (pj_int16_t*)frame->buf);
	}
	}

	return PJ_SUCCESS;
	}


	/*
	* The callback called by sound recorder when it has finished capturing a
	* frame.
	*/
	static pj_status_t rec_cb(void user_data, pjmedia_frame frame)
	{
	pjmedia_snd_port snd_port = (pjmedia_snd_port) user_data;
	pjmedia_port *port;

	pjmedia_clock_src_update(&snd_port->cap_clocksrc, &frame->timestamp);

	port = snd_port->port;
	if (port == NULL)
	return PJ_SUCCESS;

	/* Cancel echo */
	if (snd_port->ec_state && !snd_port->ec_suspended) {
	pjmedia_echo_capture(snd_port->ec_state, (pj_int16_t*) frame->buf, 0);
	}

	pjmedia_port_put_frame(port, frame);


	return PJ_SUCCESS;
	}

	/*
	* The callback called by sound player when it needs more samples to be
	* played. This version is for non-PCM data.
	*/
	static pj_status_t play_cb_ext(void user_data, pjmedia_frame frame)
	{
	pjmedia_snd_port snd_port = (pjmedia_snd_port) user_data;
	pjmedia_port *port = snd_port->port;

	if (port == NULL) {
	frame->type = PJMEDIA_FRAME_TYPE_NONE;
	return PJ_SUCCESS;
	}

	pjmedia_port_get_frame(port, frame);

	return PJ_SUCCESS;
	}


	/*
	* The callback called by sound recorder when it has finished capturing a
	* frame. This version is for non-PCM data.
	*/
	static pj_status_t rec_cb_ext(void user_data, pjmedia_frame frame)
	{
	pjmedia_snd_port snd_port = (pjmedia_snd_port) user_data;
	pjmedia_port *port;

	port = snd_port->port;
	if (port == NULL)
	return PJ_SUCCESS;

	pjmedia_port_put_frame(port, frame);

	return PJ_SUCCESS;
	}

	/* Initialize with default values (zero) */
	PJ_DEF(void) pjmedia_snd_port_param_default(pjmedia_snd_port_param *prm)
	{
	pj_bzero(prm, sizeof(*prm));
	}

	/*
	* Start the sound stream.
	* This may be called even when the sound stream has already been started.
	*/
	static pj_status_t start_sound_device( pj_pool_t *pool,
	pjmedia_snd_port *snd_port )
	{
	pjmedia_aud_rec_cb snd_rec_cb;
	pjmedia_aud_play_cb snd_play_cb;
	pjmedia_aud_param param_copy;
	pj_status_t status;

	/* Check if sound has been started. */
	if (snd_port->aud_stream != NULL)
	return PJ_SUCCESS;

	PJ_ASSERT_RETURN(snd_port->dir == PJMEDIA_DIR_CAPTURE \|\|
	snd_port->dir == PJMEDIA_DIR_PLAYBACK \|\|
	snd_port->dir == PJMEDIA_DIR_CAPTURE_PLAYBACK,
	PJ_EBUG);

	/* Get device caps */
	if (snd_port->aud_param.dir & PJMEDIA_DIR_CAPTURE) {
	pjmedia_aud_dev_info dev_info;

	status = pjmedia_aud_dev_get_info(snd_port->aud_param.rec_id,
	&dev_info);
	if (status != PJ_SUCCESS)
	return status;

	snd_port->aud_caps = dev_info.caps;
	} else {
	snd_port->aud_caps = 0;
	}

	/* Process EC settings */
	pj_memcpy(&param_copy, &snd_port->aud_param, sizeof(param_copy));
	if (param_copy.flags & PJMEDIA_AUD_DEV_CAP_EC) {
	/* EC is wanted */
	if ((snd_port->prm_ec_options & PJMEDIA_ECHO_USE_SW_ECHO) == 0 &&
	(snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC))
	{
	/* Device supports EC */
	/* Nothing to do */
	} else {
	/* Application wants to use software EC or device
	* doesn't support EC, remove EC settings from
	* device parameters
	*/
	param_copy.flags &= ~(PJMEDIA_AUD_DEV_CAP_EC \|
	PJMEDIA_AUD_DEV_CAP_EC_TAIL);
	}
	}

	/* Use different callback if format is not PCM */
	if (snd_port->aud_param.ext_fmt.id == PJMEDIA_FORMAT_L16) {
	snd_rec_cb = &rec_cb;
	snd_play_cb = &play_cb;
	} else {
	snd_rec_cb = &rec_cb_ext;
	snd_play_cb = &play_cb_ext;
	}

	/* Open the device */
	status = pjmedia_aud_stream_create(&param_copy,
	snd_rec_cb,
	snd_play_cb,
	snd_port,
	&snd_port->aud_stream);

	if (status != PJ_SUCCESS)
	return status;

	/* Inactivity limit before EC is suspended. */
	snd_port->ec_suspend_limit = AEC_SUSPEND_LIMIT *
	(snd_port->clock_rate /
	snd_port->samples_per_frame);

	/* Create software EC if parameter specifies EC and
	* (app specifically requests software EC or device
	* doesn't support EC). Only do this if the format is PCM!
	*/
	if ((snd_port->aud_param.flags & PJMEDIA_AUD_DEV_CAP_EC) &&
	((snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC)==0 \|\|
	(snd_port->prm_ec_options & PJMEDIA_ECHO_USE_SW_ECHO) != 0) &&
	param_copy.ext_fmt.id == PJMEDIA_FORMAT_PCM)
	{
	if ((snd_port->aud_param.flags & PJMEDIA_AUD_DEV_CAP_EC_TAIL)==0) {
	snd_port->aud_param.flags \|= PJMEDIA_AUD_DEV_CAP_EC_TAIL;
	snd_port->aud_param.ec_tail_ms = AEC_TAIL;
	PJ_LOG(4,(THIS_FILE, "AEC tail is set to default %u ms",
	snd_port->aud_param.ec_tail_ms));
	}

	status = pjmedia_snd_port_set_ec(snd_port, pool,
	snd_port->aud_param.ec_tail_ms,
	snd_port->prm_ec_options);
	if (status != PJ_SUCCESS) {
	pjmedia_aud_stream_destroy(snd_port->aud_stream);
	snd_port->aud_stream = NULL;
	return status;
	}
	}

	/* Start sound stream. */
	if (!(snd_port->options & PJMEDIA_SND_PORT_NO_AUTO_START)) {
	status = pjmedia_aud_stream_start(snd_port->aud_stream);
	}
	if (status != PJ_SUCCESS) {
	pjmedia_aud_stream_destroy(snd_port->aud_stream);
	snd_port->aud_stream = NULL;
	return status;
	}

	return PJ_SUCCESS;
	}


	/*
	* Stop the sound device.
	* This may be called even when there's no sound device in the port.
	*/
	static pj_status_t stop_sound_device( pjmedia_snd_port *snd_port )
	{
	/* Check if we have sound stream device. */
	if (snd_port->aud_stream) {
	pjmedia_aud_stream_stop(snd_port->aud_stream);
	pjmedia_aud_stream_destroy(snd_port->aud_stream);
	snd_port->aud_stream = NULL;
	}

	/* Destroy AEC */
	if (snd_port->ec_state) {
	pjmedia_echo_destroy(snd_port->ec_state);
	snd_port->ec_state = NULL;
	}

	return PJ_SUCCESS;
	}


	/*
	* Create bidirectional port.
	*/
	PJ_DEF(pj_status_t) pjmedia_snd_port_create( pj_pool_t *pool,
	int rec_id,
	int play_id,
	unsigned clock_rate,
	unsigned channel_count,
	unsigned samples_per_frame,
	unsigned bits_per_sample,
	unsigned options,
	pjmedia_snd_port **p_port)
	{
	pjmedia_snd_port_param param;
	pj_status_t status;

	pjmedia_snd_port_param_default(&param);

	status = pjmedia_aud_dev_default_param(rec_id, &param.base);
	if (status != PJ_SUCCESS)
	return status;

	param.base.dir = PJMEDIA_DIR_CAPTURE_PLAYBACK;
	param.base.rec_id = rec_id;
	param.base.play_id = play_id;
	param.base.clock_rate = clock_rate;
	param.base.channel_count = channel_count;
	param.base.samples_per_frame = samples_per_frame;
	param.base.bits_per_sample = bits_per_sample;
	param.options = options;
	param.ec_options = 0;

	return pjmedia_snd_port_create2(pool, &param, p_port);
	}

	/*
	* Create sound recorder AEC.
	*/
	PJ_DEF(pj_status_t) pjmedia_snd_port_create_rec( pj_pool_t *pool,
	int dev_id,
	unsigned clock_rate,
	unsigned channel_count,
	unsigned samples_per_frame,
	unsigned bits_per_sample,
	unsigned options,
	pjmedia_snd_port **p_port)
	{
	pjmedia_snd_port_param param;
	pj_status_t status;

	pjmedia_snd_port_param_default(&param);

	status = pjmedia_aud_dev_default_param(dev_id, &param.base);
	if (status != PJ_SUCCESS)
	return status;

	param.base.dir = PJMEDIA_DIR_CAPTURE;
	param.base.rec_id = dev_id;
	param.base.clock_rate = clock_rate;
	param.base.channel_count = channel_count;
	param.base.samples_per_frame = samples_per_frame;
	param.base.bits_per_sample = bits_per_sample;
	param.options = options;
	param.ec_options = 0;

	return pjmedia_snd_port_create2(pool, &param, p_port);
	}


	/*
	* Create sound player port.
	*/
	PJ_DEF(pj_status_t) pjmedia_snd_port_create_player( pj_pool_t *pool,
	int dev_id,
	unsigned clock_rate,
	unsigned channel_count,
	unsigned samples_per_frame,
	unsigned bits_per_sample,
	unsigned options,
	pjmedia_snd_port **p_port)
	{
	pjmedia_snd_port_param param;
	pj_status_t status;

	pjmedia_snd_port_param_default(&param);

	status = pjmedia_aud_dev_default_param(dev_id, &param.base);
	if (status != PJ_SUCCESS)
	return status;

	param.base.dir = PJMEDIA_DIR_PLAYBACK;
	param.base.play_id = dev_id;
	param.base.clock_rate = clock_rate;
	param.base.channel_count = channel_count;
	param.base.samples_per_frame = samples_per_frame;
	param.base.bits_per_sample = bits_per_sample;
	param.options = options;
	param.ec_options = 0;

	return pjmedia_snd_port_create2(pool, &param, p_port);
	}


	/*
	* Create sound port.
	*/
	PJ_DEF(pj_status_t) pjmedia_snd_port_create2(pj_pool_t *pool,
	const pjmedia_snd_port_param *prm,
	pjmedia_snd_port **p_port)
	{
	pjmedia_snd_port *snd_port;
	pj_status_t status;
	unsigned ptime_usec;

	PJ_ASSERT_RETURN(pool && prm && p_port, PJ_EINVAL);

	snd_port = PJ_POOL_ZALLOC_T(pool, pjmedia_snd_port);
	PJ_ASSERT_RETURN(snd_port, PJ_ENOMEM);

	snd_port->dir = prm->base.dir;
	snd_port->rec_id = prm->base.rec_id;
	snd_port->play_id = prm->base.play_id;
	snd_port->clock_rate = prm->base.clock_rate;
	snd_port->channel_count = prm->base.channel_count;
	snd_port->samples_per_frame = prm->base.samples_per_frame;
	snd_port->bits_per_sample = prm->base.bits_per_sample;
	pj_memcpy(&snd_port->aud_param, &prm->base, sizeof(snd_port->aud_param));
	snd_port->options = prm->options;
	snd_port->prm_ec_options = prm->ec_options;

	ptime_usec = prm->base.samples_per_frame * 1000 / prm->base.channel_count /
	prm->base.clock_rate * 1000;
	pjmedia_clock_src_init(&snd_port->cap_clocksrc, PJMEDIA_TYPE_AUDIO,
	snd_port->clock_rate, ptime_usec);
	pjmedia_clock_src_init(&snd_port->play_clocksrc, PJMEDIA_TYPE_AUDIO,
	snd_port->clock_rate, ptime_usec);

	/* Start sound device immediately.
	* If there's no port connected, the sound callback will return
	* empty signal.
	*/
	status = start_sound_device( pool, snd_port );
	if (status != PJ_SUCCESS) {
	pjmedia_snd_port_destroy(snd_port);
	return status;
	}

	*p_port = snd_port;
	return PJ_SUCCESS;
	}


	/*
	* Destroy port (also destroys the sound device).
	*/
	PJ_DEF(pj_status_t) pjmedia_snd_port_destroy(pjmedia_snd_port *snd_port)
	{
	PJ_ASSERT_RETURN(snd_port, PJ_EINVAL);

	return stop_sound_device(snd_port);
	}


	/*
	* Retrieve the sound stream associated by this sound device port.
	*/
	PJ_DEF(pjmedia_aud_stream*) pjmedia_snd_port_get_snd_stream(
	pjmedia_snd_port *snd_port)
	{
	PJ_ASSERT_RETURN(snd_port, NULL);
	return snd_port->aud_stream;
	}


	/*
	* Change EC settings.
	*/
	PJ_DEF(pj_status_t) pjmedia_snd_port_set_ec( pjmedia_snd_port *snd_port,
	pj_pool_t *pool,
	unsigned tail_ms,
	unsigned options)
	{
	pjmedia_aud_param prm;
	pj_status_t status;

	/* Sound must be opened in full-duplex mode */
	PJ_ASSERT_RETURN(snd_port &&
	snd_port->dir == PJMEDIA_DIR_CAPTURE_PLAYBACK,
	PJ_EINVALIDOP);

	/* Determine whether we use device or software EC */
	if ((snd_port->prm_ec_options & PJMEDIA_ECHO_USE_SW_ECHO) == 0 &&
	(snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC))
	{
	/* We use device EC */
	pj_bool_t ec_enabled;

	/* Query EC status */
	status = pjmedia_aud_stream_get_cap(snd_port->aud_stream,
	PJMEDIA_AUD_DEV_CAP_EC,
	&ec_enabled);
	if (status != PJ_SUCCESS)
	return status;

	if (tail_ms != 0) {
	/* Change EC setting */

	if (!ec_enabled) {
	/* Enable EC first */
	pj_bool_t value = PJ_TRUE;
	status = pjmedia_aud_stream_set_cap(snd_port->aud_stream,
	PJMEDIA_AUD_DEV_CAP_EC,
	&value);
	if (status != PJ_SUCCESS)
	return status;
	}

	if ((snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC_TAIL)==0) {
	/* Device does not support setting EC tail */
	return PJMEDIA_EAUD_INVCAP;
	}

	return pjmedia_aud_stream_set_cap(snd_port->aud_stream,
	PJMEDIA_AUD_DEV_CAP_EC_TAIL,
	&tail_ms);

	} else if (ec_enabled) {
	/* Disable EC */
	pj_bool_t value = PJ_FALSE;
	return pjmedia_aud_stream_set_cap(snd_port->aud_stream,
	PJMEDIA_AUD_DEV_CAP_EC,
	&value);
	} else {
	/* Request to disable EC but EC has been disabled */
	/* Do nothing */
	return PJ_SUCCESS;
	}

	} else {
	/* We use software EC */

	/* Check if there is change in parameters */
	if (tail_ms==snd_port->ec_tail_len && options==snd_port->ec_options) {
	PJ_LOG(5,(THIS_FILE, "pjmedia_snd_port_set_ec() ignored, no "
	"change in settings"));
	return PJ_SUCCESS;
	}

	status = pjmedia_aud_stream_get_param(snd_port->aud_stream, &prm);
	if (status != PJ_SUCCESS)
	return status;

	/* Audio stream must be in PCM format */
	PJ_ASSERT_RETURN(prm.ext_fmt.id == PJMEDIA_FORMAT_PCM,
	PJ_EINVALIDOP);

	/* Destroy AEC */
	if (snd_port->ec_state) {
	pjmedia_echo_destroy(snd_port->ec_state);
	snd_port->ec_state = NULL;
	}

	if (tail_ms != 0) {
	unsigned delay_ms;

	//No need to add input latency in the latency calculation,
	//since actual input latency should be zero.
	//delay_ms = (si.rec_latency + si.play_latency) * 1000 /
	// snd_port->clock_rate;
	/* Set EC latency to 3/4 of output latency to reduce the
	* possibility of missing/late reference frame.
	*/
	delay_ms = prm.output_latency_ms * 3/4;
	status = pjmedia_echo_create2(pool, snd_port->clock_rate,
	snd_port->channel_count,
	snd_port->samples_per_frame,
	tail_ms, delay_ms,
	options, &snd_port->ec_state);
	if (status != PJ_SUCCESS)
	snd_port->ec_state = NULL;
	else
	snd_port->ec_suspended = PJ_FALSE;
	} else {
	PJ_LOG(4,(THIS_FILE, "Echo canceller is now disabled in the "
	"sound port"));
	status = PJ_SUCCESS;
	}

	snd_port->ec_options = options;
	snd_port->ec_tail_len = tail_ms;
	}

	return status;
	}


	/* Get AEC tail length */
	PJ_DEF(pj_status_t) pjmedia_snd_port_get_ec_tail( pjmedia_snd_port *snd_port,
	unsigned *p_length)
	{
	PJ_ASSERT_RETURN(snd_port && p_length, PJ_EINVAL);

	/* Determine whether we use device or software EC */
	if (snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC) {
	/* We use device EC */
	pj_bool_t ec_enabled;
	pj_status_t status;

	/* Query EC status */
	status = pjmedia_aud_stream_get_cap(snd_port->aud_stream,
	PJMEDIA_AUD_DEV_CAP_EC,
	&ec_enabled);
	if (status != PJ_SUCCESS)
	return status;

	if (!ec_enabled) {
	*p_length = 0;
	} else if (snd_port->aud_caps & PJMEDIA_AUD_DEV_CAP_EC_TAIL) {
	/* Get device EC tail */
	status = pjmedia_aud_stream_get_cap(snd_port->aud_stream,
	PJMEDIA_AUD_DEV_CAP_EC_TAIL,
	p_length);
	if (status != PJ_SUCCESS)
	return status;
	} else {
	/* Just use default */
	*p_length = AEC_TAIL;
	}

	} else {
	/* We use software EC */
	*p_length = snd_port->ec_state ? snd_port->ec_tail_len : 0;
	}
	return PJ_SUCCESS;
	}


	/*
	* Get clock source.
	*/
	PJ_DEF(pjmedia_clock_src *)
	pjmedia_snd_port_get_clock_src( pjmedia_snd_port *snd_port,
	pjmedia_dir dir )
	{
	return (dir == PJMEDIA_DIR_CAPTURE? &snd_port->cap_clocksrc:
	&snd_port->play_clocksrc);
	}


	/*
	* Connect a port.
	*/
	PJ_DEF(pj_status_t) pjmedia_snd_port_connect( pjmedia_snd_port *snd_port,
	pjmedia_port *port)
	{
	pjmedia_audio_format_detail *afd;

	PJ_ASSERT_RETURN(snd_port && port, PJ_EINVAL);

	afd = pjmedia_format_get_audio_format_detail(&port->info.fmt, PJ_TRUE);

	/* Check that port has the same configuration as the sound device
	* port.
	*/
	if (afd->clock_rate != snd_port->clock_rate)
	return PJMEDIA_ENCCLOCKRATE;

	if (PJMEDIA_AFD_SPF(afd) != snd_port->samples_per_frame)
	return PJMEDIA_ENCSAMPLESPFRAME;

	if (afd->channel_count != snd_port->channel_count)
	return PJMEDIA_ENCCHANNEL;

	if (afd->bits_per_sample != snd_port->bits_per_sample)
	return PJMEDIA_ENCBITS;

	/* Port is okay. */
	snd_port->port = port;
	return PJ_SUCCESS;
	}


	/*
	* Get the connected port.
	*/
	PJ_DEF(pjmedia_port) pjmedia_snd_port_get_port(pjmedia_snd_port snd_port)
	{
	PJ_ASSERT_RETURN(snd_port, NULL);
	return snd_port->port;
	}


	/*
	* Disconnect port.
	*/
	PJ_DEF(pj_status_t) pjmedia_snd_port_disconnect(pjmedia_snd_port *snd_port)
	{
	PJ_ASSERT_RETURN(snd_port, PJ_EINVAL);

	snd_port->port = NULL;

	return PJ_SUCCESS;
	}