---

00:00:18.763 WEST_TOPDIR/ze  ..Assert failed: samples_per_frame > 0
00:00:18.769    pjsua_aud.c  ..Error creating conference bridge: Unknown pjlib error 70004 [status=70004]
error_exit(687) ERROR=Error in pjsua_init() status=70004
00:00:18.784            APP  Error in pjsua_init(): Unknown pjlib error 70004 [status=70004]

PJ_DEF(pj_status_t) pjmedia_conf_create( pj_pool_t *pool_,
                                         unsigned max_ports,
                                         unsigned clock_rate,
                                         unsigned channel_count,
                                         unsigned samples_per_frame,
                                         unsigned bits_per_sample,
                                         unsigned options,
                                         pjmedia_conf **p_conf )
{
    pj_pool_t *pool;
    pjmedia_conf *conf;
    const pj_str_t name = { "Conf", 4 };
    pj_status_t status;

    PJ_ASSERT_RETURN(samples_per_frame > 0, PJ_EINVAL);
    /* Can only accept 16bits per sample, for now.. */

думаю надо протянуть в систему snd_port.c установку sample_rate
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);

    /* Normalize rec_id & play_id */
    if (rec_id < 0)
        rec_id = PJMEDIA_AUD_DEFAULT_CAPTURE_DEV;
    if (play_id < 0)
        play_id = PJMEDIA_AUD_DEFAULT_PLAYBACK_DEV;

    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);
}

т.е. возможность динамически устанавливать sample_rate после согласования кодеков, либо полное отключение ресэмлинга, если стоит такая настройка, а железные аудио устройства настраивать как входной кодек