/* 
 * 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-codec/speex.h>
#include <pjmedia/codec.h>
#include <pjmedia/errno.h>
#include <pjmedia/endpoint.h>
#include <pjmedia/port.h>
#include <pj/assert.h>
#include <pj/log.h>
#include <pj/pool.h>
#include <pj/string.h>
#include <pj/os.h>

/*
 * Only build this file if PJMEDIA_HAS_SPEEX_CODEC != 0
 */
#if defined(PJMEDIA_HAS_SPEEX_CODEC) && PJMEDIA_HAS_SPEEX_CODEC!=0

#include <speex/speex.h>

#define THIS_FILE   "speex_codec.c"

/* Prototypes for Speex factory */
static pj_status_t spx_test_alloc( pjmedia_codec_factory *factory, 
                                   const pjmedia_codec_info *id );
static pj_status_t spx_default_attr( pjmedia_codec_factory *factory, 
                                     const pjmedia_codec_info *id, 
                                     pjmedia_codec_param *attr );
static pj_status_t spx_enum_codecs( pjmedia_codec_factory *factory, 
                                    unsigned *count, 
                                    pjmedia_codec_info codecs[]);
static pj_status_t spx_alloc_codec( pjmedia_codec_factory *factory, 
                                    const pjmedia_codec_info *id, 
                                    pjmedia_codec **p_codec);
static pj_status_t spx_dealloc_codec( pjmedia_codec_factory *factory, 
                                      pjmedia_codec *codec );

/* Prototypes for Speex implementation. */
static pj_status_t  spx_codec_init( pjmedia_codec *codec, 
                                    pj_pool_t *pool );
static pj_status_t  spx_codec_open( pjmedia_codec *codec, 
                                    pjmedia_codec_param *attr );
static pj_status_t  spx_codec_close( pjmedia_codec *codec );
static pj_status_t  spx_codec_modify(pjmedia_codec *codec, 
                                     const pjmedia_codec_param *attr );
static pj_status_t  spx_codec_parse( pjmedia_codec *codec,
                                     void *pkt,
                                     pj_size_t pkt_size,
                                     const pj_timestamp *ts,
                                     unsigned *frame_cnt,
                                     pjmedia_frame frames[]);
static pj_status_t  spx_codec_encode( pjmedia_codec *codec, 
                                      const struct pjmedia_frame *input,
                                      unsigned output_buf_len, 
                                      struct pjmedia_frame *output);
static pj_status_t  spx_codec_decode( pjmedia_codec *codec, 
                                      const struct pjmedia_frame *input,
                                      unsigned output_buf_len, 
                                      struct pjmedia_frame *output);
static pj_status_t  spx_codec_recover(pjmedia_codec *codec, 
                                      unsigned output_buf_len, 
                                      struct pjmedia_frame *output);

/* Definition for Speex codec operations. */
static pjmedia_codec_op spx_op = 
{
    &spx_codec_init,
    &spx_codec_open,
    &spx_codec_close,
    &spx_codec_modify,
    &spx_codec_parse,
    &spx_codec_encode,
    &spx_codec_decode,
    &spx_codec_recover
};

/* Definition for Speex codec factory operations. */
static pjmedia_codec_factory_op spx_factory_op =
{
    &spx_test_alloc,
    &spx_default_attr,
    &spx_enum_codecs,
    &spx_alloc_codec,
    &spx_dealloc_codec,
    &pjmedia_codec_speex_deinit
};

/* Index to Speex parameter. */
enum
{
    PARAM_NB,   /* Index for narrowband parameter.      */
    PARAM_WB,   /* Index for wideband parameter.        */
    PARAM_UWB,  /* Index for ultra-wideband parameter   */
};

/* Speex default parameter */
struct speex_param
{
    int              enabled;           /* Is this mode enabled?            */
    const SpeexMode *mode;              /* Speex mode.                      */
    int              pt;                /* Payload type.                    */
    unsigned         clock_rate;        /* Default sampling rate to be used.*/
    int              quality;           /* Default encoder quality.         */
    int              complexity;        /* Default encoder complexity.      */
    int              samples_per_frame; /* Samples per frame.               */
    int              framesize;         /* Frame size for current mode.     */
    int              bitrate;           /* Bit rate for current mode.       */
    int              max_bitrate;       /* Max bit rate for current mode.   */
};

/* Speex factory */
static struct spx_factory
{
    pjmedia_codec_factory    base;
    pjmedia_endpt           *endpt;
    pj_pool_t               *pool;
    pj_mutex_t              *mutex;
    pjmedia_codec            codec_list;
    struct speex_param       speex_param[3];

} spx_factory;

/* Speex codec private data. */
struct spx_private
{
    int                  param_id;          /**< Index to speex param.  */

    void                *enc;               /**< Encoder state.         */
    SpeexBits            enc_bits;          /**< Encoder bits.          */
    void                *dec;               /**< Decoder state.         */
    SpeexBits            dec_bits;          /**< Decoder bits.          */
};


/*
 * Get codec bitrate and frame size.
 */
static pj_status_t get_speex_info( struct speex_param *p )
{
    void *state;
    int tmp;

    /* Create temporary encoder */
    state = speex_encoder_init(p->mode);
    if (!state)
        return PJMEDIA_CODEC_EFAILED;

    /* Set the quality */
    if (p->quality != -1)
        speex_encoder_ctl(state, SPEEX_SET_QUALITY, &p->quality);

    /* Sampling rate. */
    speex_encoder_ctl(state, SPEEX_SET_SAMPLING_RATE, &p->clock_rate);

    /* VAD off to have max bitrate */
    tmp = 0;
    speex_encoder_ctl(state, SPEEX_SET_VAD, &tmp);

    /* Complexity. */
    if (p->complexity != -1)
        speex_encoder_ctl(state, SPEEX_SET_COMPLEXITY, &p->complexity);

    /* Now get the frame size */
    speex_encoder_ctl(state, SPEEX_GET_FRAME_SIZE, &p->samples_per_frame);

    /* Now get the average bitrate */
    speex_encoder_ctl(state, SPEEX_GET_BITRATE, &p->bitrate);

    /* Calculate framesize. */
    p->framesize = p->bitrate * 20 / 1000;

    /* Now get the maximum bitrate by using maximum quality (=10) */
    tmp = 10;
    speex_encoder_ctl(state, SPEEX_SET_QUALITY, &tmp);
    speex_encoder_ctl(state, SPEEX_GET_BITRATE, &p->max_bitrate);

    /* Destroy encoder. */
    speex_encoder_destroy(state);

    return PJ_SUCCESS;
}

/*
 * Initialize and register Speex codec factory to pjmedia endpoint.
 */
PJ_DEF(pj_status_t) pjmedia_codec_speex_init( pjmedia_endpt *endpt,
                                              unsigned options,
                                              int quality,
                                              int complexity )
{
    pjmedia_codec_mgr *codec_mgr;
    unsigned i;
    pj_status_t status;

    if (spx_factory.pool != NULL) {
        /* Already initialized. */
        return PJ_SUCCESS;
    }

    /* Get defaults */
    if (quality < 0) quality = PJMEDIA_CODEC_SPEEX_DEFAULT_QUALITY;
    if (complexity < 0) complexity = PJMEDIA_CODEC_SPEEX_DEFAULT_COMPLEXITY;

    /* Validate quality & complexity */
    PJ_ASSERT_RETURN(quality >= 0 && quality <= 10, PJ_EINVAL);
    PJ_ASSERT_RETURN(complexity >= 1 && complexity <= 10, PJ_EINVAL);

    /* Create Speex codec factory. */
    spx_factory.base.op = &spx_factory_op;
    spx_factory.base.factory_data = NULL;
    spx_factory.endpt = endpt;

    spx_factory.pool = pjmedia_endpt_create_pool(endpt, "speex", 
                                                       1000, 4000);
    if (!spx_factory.pool)
        return PJ_ENOMEM;

    pj_list_init(&spx_factory.codec_list);

    /* Create mutex. */
    status = pj_mutex_create_simple(spx_factory.pool, "speex", 
                                    &spx_factory.mutex);
    if (status != PJ_SUCCESS)
        goto on_error;

    /* Initialize default Speex parameter. */
    spx_factory.speex_param[PARAM_NB].enabled = 
        ((options & PJMEDIA_SPEEX_NO_NB) == 0);
    spx_factory.speex_param[PARAM_NB].pt = PJMEDIA_RTP_PT_SPEEX_NB;
    spx_factory.speex_param[PARAM_NB].mode = speex_lib_get_mode(SPEEX_MODEID_NB);
    spx_factory.speex_param[PARAM_NB].clock_rate = 8000;
    spx_factory.speex_param[PARAM_NB].quality = quality;
    spx_factory.speex_param[PARAM_NB].complexity = complexity;

    spx_factory.speex_param[PARAM_WB].enabled = 
        ((options & PJMEDIA_SPEEX_NO_WB) == 0);
    spx_factory.speex_param[PARAM_WB].pt = PJMEDIA_RTP_PT_SPEEX_WB;
    spx_factory.speex_param[PARAM_WB].mode = speex_lib_get_mode(SPEEX_MODEID_WB);
    spx_factory.speex_param[PARAM_WB].clock_rate = 16000;
    spx_factory.speex_param[PARAM_WB].quality = quality;
    spx_factory.speex_param[PARAM_WB].complexity = complexity;

    spx_factory.speex_param[PARAM_UWB].enabled = 
        ((options & PJMEDIA_SPEEX_NO_UWB) == 0);
    spx_factory.speex_param[PARAM_UWB].pt = PJMEDIA_RTP_PT_SPEEX_UWB;
    spx_factory.speex_param[PARAM_UWB].mode = speex_lib_get_mode(SPEEX_MODEID_UWB);
    spx_factory.speex_param[PARAM_UWB].clock_rate = 32000;
    spx_factory.speex_param[PARAM_UWB].quality = quality;
    spx_factory.speex_param[PARAM_UWB].complexity = complexity;

    /* Somehow quality <=4 is broken in linux. */
    if (quality <= 4 && quality >= 0) {
        PJ_LOG(5,(THIS_FILE, "Adjusting quality to 5 for uwb"));
        spx_factory.speex_param[PARAM_UWB].quality = 5;
    }

    /* Get codec framesize and avg bitrate for each mode. */
    for (i=0; i<PJ_ARRAY_SIZE(spx_factory.speex_param); ++i) {
        status = get_speex_info(&spx_factory.speex_param[i]);
        PJ_ASSERT_ON_FAIL(status == PJ_SUCCESS, goto on_error);
    }

    /* Get the codec manager. */
    codec_mgr = pjmedia_endpt_get_codec_mgr(endpt);
    if (!codec_mgr) {
        status = PJ_EINVALIDOP;
        goto on_error;
    }

    /* Register codec factory to endpoint. */
    status = pjmedia_codec_mgr_register_factory(codec_mgr, 
                                                &spx_factory.base);
    if (status != PJ_SUCCESS)
        goto on_error;

    /* Done. */
    return PJ_SUCCESS;

on_error:
    pj_pool_release(spx_factory.pool);
    spx_factory.pool = NULL;
    return status;
}


/*
 * Initialize with default settings.
 */
PJ_DEF(pj_status_t) pjmedia_codec_speex_init_default(pjmedia_endpt *endpt)
{
    return pjmedia_codec_speex_init(endpt, 0, -1, -1);
}

/*
 * Change the settings of Speex codec.
 */
PJ_DEF(pj_status_t) pjmedia_codec_speex_set_param(unsigned clock_rate,
                                                  int quality,
                                                  int complexity)
{
    unsigned i;

    /* Get defaults */
    if (quality < 0) quality = PJMEDIA_CODEC_SPEEX_DEFAULT_QUALITY;
    if (complexity < 0) complexity = PJMEDIA_CODEC_SPEEX_DEFAULT_COMPLEXITY;

    /* Validate quality & complexity */
    PJ_ASSERT_RETURN(quality >= 0 && quality <= 10, PJ_EINVAL);
    PJ_ASSERT_RETURN(complexity >= 1 && complexity <= 10, PJ_EINVAL);

    /* Apply the settings */
    for (i=0; i<PJ_ARRAY_SIZE(spx_factory.speex_param); ++i) {
        if (spx_factory.speex_param[i].clock_rate == clock_rate) {
            pj_status_t status;

            spx_factory.speex_param[i].quality = quality;
            spx_factory.speex_param[i].complexity = complexity;

            /* Somehow quality<=4 is broken in linux. */
            if (i == PARAM_UWB && quality <= 4 && quality >= 0) {
                PJ_LOG(5,(THIS_FILE, "Adjusting quality to 5 for uwb"));
                spx_factory.speex_param[PARAM_UWB].quality = 5;
            }

            status = get_speex_info(&spx_factory.speex_param[i]);

            return status;
        }
    }

    return PJ_EINVAL;
}

/*
 * Unregister Speex codec factory from pjmedia endpoint and deinitialize
 * the Speex codec library.
 */
PJ_DEF(pj_status_t) pjmedia_codec_speex_deinit(void)
{
    pjmedia_codec_mgr *codec_mgr;
    pj_status_t status;

    if (spx_factory.pool == NULL) {
        /* Already deinitialized */
        return PJ_SUCCESS;
    }

    pj_mutex_lock(spx_factory.mutex);

    /* We don't want to deinit if there's outstanding codec. */
    /* This is silly, as we'll always have codec in the list if
       we ever allocate a codec! A better behavior maybe is to 
       deallocate all codecs in the list.
    if (!pj_list_empty(&spx_factory.codec_list)) {
        pj_mutex_unlock(spx_factory.mutex);
        return PJ_EBUSY;
    }
    */

    /* Get the codec manager. */
    codec_mgr = pjmedia_endpt_get_codec_mgr(spx_factory.endpt);
    if (!codec_mgr) {
        pj_pool_release(spx_factory.pool);
        spx_factory.pool = NULL;
        pj_mutex_unlock(spx_factory.mutex);
        return PJ_EINVALIDOP;
    }

    /* Release the factory mutex before calling unregister to avoid lock
     * order inversion with codec manager mutex.
     */
    pj_mutex_unlock(spx_factory.mutex);

    /* Unregister Speex codec factory. */
    status = pjmedia_codec_mgr_unregister_factory(codec_mgr,
                                                  &spx_factory.base);
    
    /* Destroy mutex. */
    pj_mutex_destroy(spx_factory.mutex);
    spx_factory.mutex = NULL;

    /* Destroy pool. */
    pj_pool_release(spx_factory.pool);
    spx_factory.pool = NULL;

    return status;
}

/* 
 * Check if factory can allocate the specified codec. 
 */
static pj_status_t spx_test_alloc( pjmedia_codec_factory *factory, 
                                   const pjmedia_codec_info *info )
{
    const pj_str_t speex_tag = { "speex", 5};
    unsigned i;

    PJ_UNUSED_ARG(factory);

    /* Type MUST be audio. */
    if (info->type != PJMEDIA_TYPE_AUDIO)
        return PJMEDIA_CODEC_EUNSUP;

    /* Check encoding name. */
    if (pj_stricmp(&info->encoding_name, &speex_tag) != 0)
        return PJMEDIA_CODEC_EUNSUP;

    /* Check clock-rate */
    for (i=0; i<PJ_ARRAY_SIZE(spx_factory.speex_param); ++i) {
        if (info->clock_rate == spx_factory.speex_param[i].clock_rate) {
            /* Okay, let's Speex! */
            return PJ_SUCCESS;
        }
    }

    
    /* Unsupported, or mode is disabled. */
    return PJMEDIA_CODEC_EUNSUP;
}

/*
 * Generate default attribute.
 */
static pj_status_t spx_default_attr (pjmedia_codec_factory *factory, 
                                      const pjmedia_codec_info *id, 
                                      pjmedia_codec_param *attr )
{

    PJ_ASSERT_RETURN(factory==&spx_factory.base, PJ_EINVAL);

    pj_bzero(attr, sizeof(pjmedia_codec_param));
    attr->info.pt = (pj_uint8_t)id->pt;
    attr->info.channel_cnt = 1;

    if (id->clock_rate <= 8000) {
        attr->info.clock_rate = spx_factory.speex_param[PARAM_NB].clock_rate;
        attr->info.avg_bps = spx_factory.speex_param[PARAM_NB].bitrate;
        attr->info.max_bps = spx_factory.speex_param[PARAM_NB].max_bitrate;

    } else if (id->clock_rate <= 16000) {
        attr->info.clock_rate = spx_factory.speex_param[PARAM_WB].clock_rate;
        attr->info.avg_bps = spx_factory.speex_param[PARAM_WB].bitrate;
        attr->info.max_bps = spx_factory.speex_param[PARAM_WB].max_bitrate;

    } else {
        /* Wow.. somebody is doing ultra-wideband. Cool...! */
        attr->info.clock_rate = spx_factory.speex_param[PARAM_UWB].clock_rate;
        attr->info.avg_bps = spx_factory.speex_param[PARAM_UWB].bitrate;
        attr->info.max_bps = spx_factory.speex_param[PARAM_UWB].max_bitrate;
    }

    attr->info.pcm_bits_per_sample = 16;
    attr->info.frm_ptime = 20;
    attr->info.pt = (pj_uint8_t)id->pt;

    attr->setting.frm_per_pkt = 1;

    /* Default flags. */
    attr->setting.cng = 1;
    attr->setting.plc = 1;
    attr->setting.penh =1 ;
    attr->setting.vad = 1;

    return PJ_SUCCESS;
}

/*
 * Enum codecs supported by this factory (i.e. only Speex!).
 */
static pj_status_t spx_enum_codecs(pjmedia_codec_factory *factory, 
                                    unsigned *count, 
                                    pjmedia_codec_info codecs[])
{
    unsigned max;
    int i;  /* Must be signed */

    PJ_UNUSED_ARG(factory);
    PJ_ASSERT_RETURN(codecs && *count > 0, PJ_EINVAL);

    max = *count;
    *count = 0;

    /*
     * We return three codecs here, and in this order:
     *  - ultra-wideband, wideband, and narrowband.
     */
    for (i=PJ_ARRAY_SIZE(spx_factory.speex_param)-1; i>=0 && *count<max; --i) {

        if (!spx_factory.speex_param[i].enabled)
            continue;

        pj_bzero(&codecs[*count], sizeof(pjmedia_codec_info));
        codecs[*count].encoding_name = pj_str("speex");
        codecs[*count].pt = spx_factory.speex_param[i].pt;
        codecs[*count].type = PJMEDIA_TYPE_AUDIO;
        codecs[*count].clock_rate = spx_factory.speex_param[i].clock_rate;
        codecs[*count].channel_cnt = 1;

        ++*count;
    }

    return PJ_SUCCESS;
}

/*
 * Allocate a new Speex codec instance.
 */
static pj_status_t spx_alloc_codec( pjmedia_codec_factory *factory, 
                                    const pjmedia_codec_info *id,
                                    pjmedia_codec **p_codec)
{
    pjmedia_codec *codec;
    struct spx_private *spx;

    PJ_ASSERT_RETURN(factory && id && p_codec, PJ_EINVAL);
    PJ_ASSERT_RETURN(factory == &spx_factory.base, PJ_EINVAL);


    pj_mutex_lock(spx_factory.mutex);

    /* Get free nodes, if any. */
    if (!pj_list_empty(&spx_factory.codec_list)) {
        codec = spx_factory.codec_list.next;
        pj_list_erase(codec);
    } else {
        codec = PJ_POOL_ZALLOC_T(spx_factory.pool, pjmedia_codec);
        PJ_ASSERT_RETURN(codec != NULL, PJ_ENOMEM);
        codec->op = &spx_op;
        codec->factory = factory;
        codec->codec_data = pj_pool_alloc(spx_factory.pool,
                                          sizeof(struct spx_private));
    }

    pj_mutex_unlock(spx_factory.mutex);

    spx = (struct spx_private*) codec->codec_data;
    spx->enc = NULL;
    spx->dec = NULL;

    if (id->clock_rate <= 8000)
        spx->param_id = PARAM_NB;
    else if (id->clock_rate <= 16000)
        spx->param_id = PARAM_WB;
    else
        spx->param_id = PARAM_UWB;

    *p_codec = codec;
    return PJ_SUCCESS;
}

/*
 * Free codec.
 */
static pj_status_t spx_dealloc_codec( pjmedia_codec_factory *factory, 
                                      pjmedia_codec *codec )
{
    struct spx_private *spx;

    PJ_ASSERT_RETURN(factory && codec, PJ_EINVAL);
    PJ_ASSERT_RETURN(factory == &spx_factory.base, PJ_EINVAL);

    /* Close codec, if it's not closed. */
    spx = (struct spx_private*) codec->codec_data;
    if (spx->enc != NULL || spx->dec != NULL) {
        spx_codec_close(codec);
    }

    /* Put in the free list. */
    pj_mutex_lock(spx_factory.mutex);
    pj_list_push_front(&spx_factory.codec_list, codec);
    pj_mutex_unlock(spx_factory.mutex);

    return PJ_SUCCESS;
}

/*
 * Init codec.
 */
static pj_status_t spx_codec_init( pjmedia_codec *codec, 
                                   pj_pool_t *pool )
{
    PJ_UNUSED_ARG(codec);
    PJ_UNUSED_ARG(pool);
    return PJ_SUCCESS;
}

/*
 * Open codec.
 */
static pj_status_t spx_codec_open( pjmedia_codec *codec, 
                                   pjmedia_codec_param *attr )
{
    struct spx_private *spx;
    int id, tmp;

    spx = (struct spx_private*) codec->codec_data;
    id = spx->param_id;

    /* 
     * Create and initialize encoder. 
     */
    spx->enc = speex_encoder_init(spx_factory.speex_param[id].mode);
    if (!spx->enc)
        return PJMEDIA_CODEC_EFAILED;
    speex_bits_init(&spx->enc_bits);

    /* Set the quality*/
    if (spx_factory.speex_param[id].quality != -1) {
        speex_encoder_ctl(spx->enc, SPEEX_SET_QUALITY, 
                          &spx_factory.speex_param[id].quality);
    }

    /* Sampling rate. */
    tmp = attr->info.clock_rate;
    speex_encoder_ctl(spx->enc, SPEEX_SET_SAMPLING_RATE, 
                      &spx_factory.speex_param[id].clock_rate);

    /* VAD */
    tmp = (attr->setting.vad != 0);
    speex_encoder_ctl(spx->enc, SPEEX_SET_VAD, &tmp);
    speex_encoder_ctl(spx->enc, SPEEX_SET_DTX, &tmp);

    /* Complexity */
    if (spx_factory.speex_param[id].complexity != -1) {
        speex_encoder_ctl(spx->enc, SPEEX_SET_COMPLEXITY, 
                          &spx_factory.speex_param[id].complexity);
    }

    /* 
     * Create and initialize decoder. 
     */
    spx->dec = speex_decoder_init(spx_factory.speex_param[id].mode);
    if (!spx->dec) {
        spx_codec_close(codec);
        return PJMEDIA_CODEC_EFAILED;
    }
    speex_bits_init(&spx->dec_bits);

    /* Sampling rate. */
    speex_decoder_ctl(spx->dec, SPEEX_SET_SAMPLING_RATE, 
                      &spx_factory.speex_param[id].clock_rate);

    /* PENH */
    tmp = attr->setting.penh;
    speex_decoder_ctl(spx->dec, SPEEX_SET_ENH, &tmp);

    return PJ_SUCCESS;
}

/*
 * Close codec.
 */
static pj_status_t spx_codec_close( pjmedia_codec *codec )
{
    struct spx_private *spx;

    spx = (struct spx_private*) codec->codec_data;

    /* Destroy encoder*/
    if (spx->enc) {
        speex_encoder_destroy( spx->enc );
        spx->enc = NULL;
        speex_bits_destroy( &spx->enc_bits );
    }

    /* Destroy decoder */
    if (spx->dec) {
        speex_decoder_destroy( spx->dec);
        spx->dec = NULL;
        speex_bits_destroy( &spx->dec_bits );
    }

    return PJ_SUCCESS;
}


/*
 * Modify codec settings.
 */
static pj_status_t  spx_codec_modify(pjmedia_codec *codec, 
                                     const pjmedia_codec_param *attr )
{
    struct spx_private *spx;
    int tmp;

    spx = (struct spx_private*) codec->codec_data;

    /* VAD */
    tmp = (attr->setting.vad != 0);
    speex_encoder_ctl(spx->enc, SPEEX_SET_VAD, &tmp);
    speex_encoder_ctl(spx->enc, SPEEX_SET_DTX, &tmp);

    /* PENH */
    tmp = attr->setting.penh;
    speex_decoder_ctl(spx->dec, SPEEX_SET_ENH, &tmp);

    return PJ_SUCCESS;
}

#if 0
#  define TRACE__(args)     PJ_LOG(5,args)
#else
#  define TRACE__(args)
#endif

#undef THIS_FUNC
#define THIS_FUNC "speex_get_next_frame"

#define NB_SUBMODES 16
#define NB_SUBMODE_BITS 4

#define SB_SUBMODES 8
#define SB_SUBMODE_BITS 3

/* This function will iterate frames & submodes in the Speex bits.
 * Returns 0 if a frame found, otherwise returns -1.
 */
static int speex_get_next_frame(SpeexBits *bits)
{
    static const int inband_skip_table[NB_SUBMODES] =
       {1, 1, 4, 4, 4, 4, 4, 4, 8, 8, 16, 16, 32, 32, 64, 64 };
    static const int wb_skip_table[SB_SUBMODES] =
       {SB_SUBMODE_BITS+1, 36, 112, 192, 352, -1, -1, -1};

    unsigned submode;
    unsigned nb_count = 0;

    while (speex_bits_remaining(bits) >= 5) {
        unsigned wb_count = 0;
        unsigned bit_ptr = bits->bitPtr;
        unsigned char_ptr = bits->charPtr;

        /* WB frame */
        while ((speex_bits_remaining(bits) >= 4)
            && speex_bits_unpack_unsigned(bits, 1))
        {
            int advance;

            submode = speex_bits_unpack_unsigned(bits, 3);
            advance = wb_skip_table[submode];
            if (advance < 0) {
                TRACE__((THIS_FUNC, "Invalid mode encountered. "
                         "The stream is corrupted."));
                return -1;
            } 
            TRACE__((THIS_FUNC, "WB layer skipped: %d bits", advance));
            advance -= (SB_SUBMODE_BITS+1);
            speex_bits_advance(bits, advance);

            bit_ptr = bits->bitPtr;
            char_ptr = bits->charPtr;

            /* Consecutive subband frames may not exceed 2 frames */
            if (++wb_count > 2)
                return -1;
        }

        /* End of bits, return the frame */
        if (speex_bits_remaining(bits) < 4) {
            TRACE__((THIS_FUNC, "End of stream"));
            return 0;
        }

        /* Stop iteration, return the frame */
        if (nb_count > 0) {
            bits->bitPtr = bit_ptr;
            bits->charPtr = char_ptr;
            return 0;
        }

        /* Get control bits */
        submode = speex_bits_unpack_unsigned(bits, 4);
        TRACE__((THIS_FUNC, "Control bits: %d at %d", 
                 submode, bits->charPtr*8+bits->bitPtr));

        if (submode == 15) {
            TRACE__((THIS_FUNC, "Found submode: terminator"));
            return -1;
        } else if (submode == 14) {
            /* in-band signal; next 4 bits contain signal id */
            submode = speex_bits_unpack_unsigned(bits, 4);
            TRACE__((THIS_FUNC, "Found submode: in-band %d bits", 
                     inband_skip_table[submode]));
            speex_bits_advance(bits, inband_skip_table[submode]);
        } else if (submode == 13) {
            /* user in-band; next 5 bits contain msg len */
            submode = speex_bits_unpack_unsigned(bits, 5);
            TRACE__((THIS_FUNC, "Found submode: user-band %d bytes", submode));
            speex_bits_advance(bits, submode * 8);
        } else if (submode > 8) {
            TRACE__((THIS_FUNC, "Unknown sub-mode %d", submode));
            return -1;
        } else {
            /* NB frame */
            int advance = submode;
            speex_mode_query(&speex_nb_mode, SPEEX_SUBMODE_BITS_PER_FRAME, &advance);
            if (advance < 0) {
                TRACE__((THIS_FUNC, "Invalid mode encountered. "
                         "The stream is corrupted."));
                return -1;
            }
            TRACE__((THIS_FUNC, "Submode %d: %d bits", submode, advance));
            advance -= (NB_SUBMODE_BITS+1);
            speex_bits_advance(bits, advance);

            ++nb_count;
        }
    }

    return 0;
}


/*
 * Get frames in the packet.
 */
static pj_status_t  spx_codec_parse( pjmedia_codec *codec,
                                     void *pkt,
                                     pj_size_t pkt_size,
                                     const pj_timestamp *ts,
                                     unsigned *frame_cnt,
                                     pjmedia_frame frames[])
{
    struct spx_private *spx = (struct spx_private*) codec->codec_data;
    unsigned samples_per_frame;
    unsigned count = 0;
    int char_ptr = 0;
    int bit_ptr = 0;

    PJ_ASSERT_RETURN(codec && ts && frames && frame_cnt, PJ_EINVAL);

    samples_per_frame=spx_factory.speex_param[spx->param_id].samples_per_frame;

    /* Copy the data into the speex bit-stream */
    speex_bits_read_from(&spx->dec_bits, (char*)pkt, (int)pkt_size);

    while (speex_get_next_frame(&spx->dec_bits) == 0 &&
           spx->dec_bits.charPtr != char_ptr &&
           count < *frame_cnt)
    {
        frames[count].buf = (char*)pkt + char_ptr;
        /* Bit info contains start bit offset of the frame */
        frames[count].bit_info = bit_ptr;
        frames[count].type = PJMEDIA_FRAME_TYPE_AUDIO;
        frames[count].timestamp.u64 = ts->u64 +
                                      (pj_uint64_t)count * samples_per_frame;
        frames[count].size = spx->dec_bits.charPtr - char_ptr;
        if (spx->dec_bits.bitPtr)
            ++frames[count].size;

        bit_ptr = spx->dec_bits.bitPtr;
        char_ptr = spx->dec_bits.charPtr;

        ++count;
    }

    *frame_cnt = count;

    return PJ_SUCCESS;
}

/*
 * Encode frames.
 */
static pj_status_t spx_codec_encode( pjmedia_codec *codec, 
                                     const struct pjmedia_frame *input,
                                     unsigned output_buf_len, 
                                     struct pjmedia_frame *output)
{
    struct spx_private *spx;
    unsigned samples_per_frame;
    int tx = 0;
    spx_int16_t *pcm_in = (spx_int16_t*)input->buf;
    pj_size_t nsamples;

    spx = (struct spx_private*) codec->codec_data;

    if (input->type != PJMEDIA_FRAME_TYPE_AUDIO) {
        output->size = 0;
        output->buf = NULL;
        output->timestamp = input->timestamp;
        output->type = input->type;
        return PJ_SUCCESS;
    }

    nsamples = input->size >> 1;
    samples_per_frame=spx_factory.speex_param[spx->param_id].samples_per_frame;

    PJ_ASSERT_RETURN(nsamples % samples_per_frame == 0, 
                     PJMEDIA_CODEC_EPCMFRMINLEN);

    /* Flush all the bits in the struct so we can encode a new frame */
    speex_bits_reset(&spx->enc_bits);

    /* Encode the frames */
    while (nsamples >= samples_per_frame) {
        tx += speex_encode_int(spx->enc, pcm_in, &spx->enc_bits);
        pcm_in += samples_per_frame;
        nsamples -= samples_per_frame;
    }

    /* Check if we need not to transmit the frame (DTX) */
    if (tx == 0) {
        output->buf = NULL;
        output->size = 0;
        output->timestamp.u64 = input->timestamp.u64;
        output->type = PJMEDIA_FRAME_TYPE_NONE;
        return PJ_SUCCESS;
    }

    /* Check size. */
    pj_assert(speex_bits_nbytes(&spx->enc_bits) <= (int)output_buf_len);

    /* Copy the bits to an array of char that can be written */
    output->size = speex_bits_write(&spx->enc_bits, 
                                    (char*)output->buf, output_buf_len);
    output->type = PJMEDIA_FRAME_TYPE_AUDIO;
    output->timestamp = input->timestamp;

    return PJ_SUCCESS;
}

/*
 * Decode frame.
 */
static pj_status_t spx_codec_decode( pjmedia_codec *codec, 
                                     const struct pjmedia_frame *input,
                                     unsigned output_buf_len, 
                                     struct pjmedia_frame *output)
{
    struct spx_private *spx;
    unsigned samples_per_frame;

    spx = (struct spx_private*) codec->codec_data;
    samples_per_frame=spx_factory.speex_param[spx->param_id].samples_per_frame;

    PJ_ASSERT_RETURN(output_buf_len >= samples_per_frame << 1,
                     PJMEDIA_CODEC_EPCMTOOSHORT);

    if (input->type != PJMEDIA_FRAME_TYPE_AUDIO) {
        pjmedia_zero_samples((pj_int16_t*)output->buf, samples_per_frame);
        output->size = samples_per_frame << 1;
        output->timestamp.u64 = input->timestamp.u64;
        output->type = PJMEDIA_FRAME_TYPE_AUDIO;
        return PJ_SUCCESS;
    }

    /* Copy the data into the bit-stream struct */
    speex_bits_read_from(&spx->dec_bits, (char*)input->buf, (int)input->size);
    
    /* Set Speex dec_bits pointer to the start bit of the frame */
    speex_bits_advance(&spx->dec_bits, input->bit_info);

    /* Decode the data */
    speex_decode_int(spx->dec, &spx->dec_bits, (spx_int16_t*)output->buf);

    output->type = PJMEDIA_FRAME_TYPE_AUDIO;
    output->size = samples_per_frame << 1;
    output->timestamp.u64 = input->timestamp.u64;

    return PJ_SUCCESS;
}

/* 
 * Recover lost frame.
 */
static pj_status_t  spx_codec_recover(pjmedia_codec *codec, 
                                      unsigned output_buf_len, 
                                      struct pjmedia_frame *output)
{
    struct spx_private *spx;
    unsigned count;

    /* output_buf_len is unreferenced when building in Release mode */
    PJ_UNUSED_ARG(output_buf_len);

    spx = (struct spx_private*) codec->codec_data;

    count = spx_factory.speex_param[spx->param_id].clock_rate * 20 / 1000;
    pj_assert(count <= output_buf_len/2);

    /* Recover packet loss */
    speex_decode_int(spx->dec, NULL, (spx_int16_t*) output->buf);

    output->size = count * 2;

    return PJ_SUCCESS;
}


#endif  /* PJMEDIA_HAS_SPEEX_CODEC */
