/* 
 * Copyright (C) 2011-2011 Teluu Inc. (http://www.teluu.com)
 *
 * 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 <pjsua-lib/pjsua.h>
#include <pjsua-lib/pjsua_internal.h>

#if defined(PJSUA_MEDIA_HAS_PJMEDIA) && PJSUA_MEDIA_HAS_PJMEDIA != 0

#define THIS_FILE       "pjsua_vid.c"

#if PJSUA_HAS_VIDEO

#define ENABLE_EVENT            1

#define PJSUA_SHOW_WINDOW       1
#define PJSUA_HIDE_WINDOW       0


static pjsua_vid_win_id vid_preview_get_win(pjmedia_vid_dev_index id,
                                            pj_bool_t running_only);
static void free_vid_win(pjsua_vid_win_id wid);
static pj_status_t media_event_unsubscribe(pjmedia_event_mgr* mgr,
                                           pjmedia_event_cb* cb,
                                           void* user_data,
                                           void* epub);

/*****************************************************************************
 * pjsua video subsystem.
 */
pj_status_t pjsua_vid_subsys_init(void)
{
    unsigned i;
    pj_status_t status;

    PJ_LOG(4,(THIS_FILE, "Initializing video subsystem.."));
    pj_log_push_indent();

    status = pjmedia_video_format_mgr_create(pjsua_var.pool, 64, 0, NULL);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Error creating PJMEDIA video format manager",
                     status);
        goto on_error;
    }

    status = pjmedia_converter_mgr_create(pjsua_var.pool, NULL);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Error creating PJMEDIA converter manager",
                     status);
        goto on_error;
    }

    status = pjmedia_vid_codec_mgr_create(pjsua_var.pool, NULL);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Error creating PJMEDIA video codec manager",
                     status);
        goto on_error;
    }

    status = pjmedia_vid_conf_create(pjsua_var.pool, NULL,
                                     &pjsua_var.vid_conf);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE,
                     "Error creating PJMEDIA video conference bridge",
                     status);
        goto on_error;
    }

#if PJMEDIA_HAS_VIDEO && PJMEDIA_HAS_VID_TOOLBOX_CODEC
    status = pjmedia_codec_vid_toolbox_init(NULL, &pjsua_var.cp.factory);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Error initializing Video Toolbox codec",
                     status);
        goto on_error;
    }
#endif

#if PJMEDIA_HAS_VIDEO && PJMEDIA_HAS_ANDROID_MEDIACODEC
    status = pjmedia_codec_and_media_vid_init(NULL, &pjsua_var.cp.factory);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Error initializing AMediaCodec library",
                     status);
        goto on_error;
    }
#endif

#if PJMEDIA_HAS_VIDEO && PJMEDIA_HAS_OPENH264_CODEC
    status = pjmedia_codec_openh264_vid_init(NULL, &pjsua_var.cp.factory);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Error initializing OpenH264 library",
                     status);
        goto on_error;
    }
#endif

#if PJMEDIA_HAS_VIDEO && PJMEDIA_HAS_FFMPEG_VID_CODEC
    status = pjmedia_codec_ffmpeg_vid_init(NULL, &pjsua_var.cp.factory);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Error initializing ffmpeg library", status);
        goto on_error;
    }
#endif

#if PJMEDIA_HAS_VIDEO && PJMEDIA_HAS_VPX_CODEC
    status = pjmedia_codec_vpx_vid_init(NULL, &pjsua_var.cp.factory);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Error initializing VPX library",
                     status);
        goto on_error;
    }
#endif

#if !defined(PJSUA_DONT_INIT_VID_DEV_SUBSYS) || \
             PJSUA_DONT_INIT_VID_DEV_SUBSYS==0
    status = pjmedia_vid_dev_subsys_init(&pjsua_var.cp.factory);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Error creating PJMEDIA video subsystem",
                     status);
        goto on_error;
    }
#endif

    for (i=0; i<PJSUA_MAX_VID_WINS; ++i) {
        if (pjsua_var.win[i].pool == NULL) {
            pjsua_var.win[i].pool = pjsua_pool_create("win%p", 512, 512);
            if (pjsua_var.win[i].pool == NULL) {
                status = PJ_ENOMEM;
                goto on_error;
            }
        }
    }

    pj_log_pop_indent();
    return PJ_SUCCESS;

on_error:
    pj_log_pop_indent();
    return status;
}

pj_status_t pjsua_vid_subsys_start(void)
{
    return PJ_SUCCESS;
}

pj_status_t pjsua_vid_subsys_destroy(void)
{
    unsigned i;

    PJ_LOG(4,(THIS_FILE, "Destroying video subsystem.."));
    pj_log_push_indent();

    for (i=0; i<PJSUA_MAX_VID_WINS; ++i) {
        if (pjsua_var.win[i].pool) {
            free_vid_win(i);
            pj_pool_release(pjsua_var.win[i].pool);
            pjsua_var.win[i].pool = NULL;
        }
    }

    if (pjsua_var.vid_conf) {
        pjmedia_vid_conf_destroy(pjsua_var.vid_conf);
        pjsua_var.vid_conf = NULL;
    }

    pjmedia_vid_dev_subsys_shutdown();

#if PJMEDIA_HAS_FFMPEG_VID_CODEC
    pjmedia_codec_ffmpeg_vid_deinit();
#endif

#if PJMEDIA_HAS_VIDEO && PJMEDIA_HAS_VID_TOOLBOX_CODEC
    pjmedia_codec_vid_toolbox_deinit();
#endif

#if defined(PJMEDIA_HAS_ANDROID_MEDIACODEC) && \
    PJMEDIA_HAS_ANDROID_MEDIACODEC != 0
    pjmedia_codec_and_media_vid_deinit();
#endif

#if defined(PJMEDIA_HAS_OPENH264_CODEC) && PJMEDIA_HAS_OPENH264_CODEC != 0
    pjmedia_codec_openh264_vid_deinit();
#endif

#if defined(PJMEDIA_HAS_VPX_CODEC) && PJMEDIA_HAS_VPX_CODEC != 0
    pjmedia_codec_vpx_vid_deinit();
#endif

    if (pjmedia_vid_codec_mgr_instance())
        pjmedia_vid_codec_mgr_destroy(NULL);

    if (pjmedia_converter_mgr_instance())
        pjmedia_converter_mgr_destroy(NULL);

    if (pjmedia_video_format_mgr_instance())
        pjmedia_video_format_mgr_destroy(NULL);

    pj_log_pop_indent();
    return PJ_SUCCESS;
}

PJ_DEF(const char*) pjsua_vid_win_type_name(pjsua_vid_win_type wt)
{
    const char *win_type_names[] = {
         "none",
         "preview",
         "stream"
    };

    return (wt < PJ_ARRAY_SIZE(win_type_names)) ? win_type_names[wt] : "??";
}

PJ_DEF(void)
pjsua_call_vid_strm_op_param_default(pjsua_call_vid_strm_op_param *param)
{
    pj_bzero(param, sizeof(*param));
    param->med_idx = -1;
    param->dir = PJMEDIA_DIR_ENCODING_DECODING;
    param->cap_dev = PJMEDIA_VID_DEFAULT_CAPTURE_DEV;
}

PJ_DEF(void) pjsua_vid_preview_param_default(pjsua_vid_preview_param *p)
{
    p->rend_id = PJMEDIA_VID_DEFAULT_RENDER_DEV;
    p->show = PJ_TRUE;
    p->wnd_flags = 0;
    pj_bzero(&p->format, sizeof(p->format));
    pj_bzero(&p->wnd, sizeof(p->wnd));
}

static pj_status_t media_event_unsubscribe(pjmedia_event_mgr* mgr,
                                           pjmedia_event_cb* cb,
                                           void* user_data,
                                           void* epub)
{
    unsigned num_locks = 0;
    pj_status_t status;

    /* Release locks before unsubscribing, to avoid deadlock. */
    num_locks = PJSUA_RELEASE_LOCK();

    status = pjmedia_event_unsubscribe(mgr, cb, user_data, epub);

    /* Re-acquire the locks. */
    PJSUA_RELOCK(num_locks);

    return status;
}

/*****************************************************************************
 * Devices.
 */

/*
 * Get the number of video devices installed in the system.
 */
PJ_DEF(unsigned) pjsua_vid_dev_count(void)
{
    return pjmedia_vid_dev_count();
}

/*
 * Retrieve the video device info for the specified device index.
 */
PJ_DEF(pj_status_t) pjsua_vid_dev_get_info(pjmedia_vid_dev_index id,
                                           pjmedia_vid_dev_info *vdi)
{
    return pjmedia_vid_dev_get_info(id, vdi);
}

/*
 * Check whether the video device is currently active.
 */
PJ_DEF(pj_bool_t) pjsua_vid_dev_is_active(pjmedia_vid_dev_index id)
{
    pjsua_vid_win_id wid = vid_preview_get_win(id, PJ_FALSE);
    
    return (wid != PJSUA_INVALID_ID? PJ_TRUE: PJ_FALSE);
}

/*
 * Set the capability of the video device.
 */
PJ_DEF(pj_status_t) pjsua_vid_dev_set_setting( pjmedia_vid_dev_index id,
                                               pjmedia_vid_dev_cap cap,
                                               const void *pval,
                                               pj_bool_t keep)
{
    pj_status_t status = PJ_SUCCESS;
    pjsua_vid_win_id wid;
    
    PJSUA_LOCK();
    wid = vid_preview_get_win(id, PJ_FALSE);
    if (wid != PJSUA_INVALID_ID) {
        pjsua_vid_win *w;
        pjmedia_vid_dev_stream *cap_dev;

        w = &pjsua_var.win[wid];
        cap_dev = pjmedia_vid_port_get_stream(w->vp_cap);

        status = pjmedia_vid_dev_stream_set_cap(cap_dev, cap, pval);
        if (status != PJ_SUCCESS) {
            PJSUA_UNLOCK();
            return status;
        }
    } else {
        status = PJ_ENOTFOUND;
    }
    PJSUA_UNLOCK();

    if (keep) {
        pjmedia_vid_dev_info info;
            
        status = pjmedia_vid_dev_get_info(id, &info);
        if (status != PJ_SUCCESS || (info.dir & PJMEDIA_DIR_CAPTURE) == 0)
            return status;
        
        /* Get real capture ID, if set to PJMEDIA_VID_DEFAULT_CAPTURE_DEV */
        id = info.id;
        status = pjmedia_vid_dev_param_set_cap(&pjsua_var.vid_param[id],
                                               cap, pval);
        if (status == PJ_SUCCESS) {
            pjsua_var.vid_caps[id] |= cap;
        }
    }
    
    return status;
}

/*
 * Get the value of the video device capability.
 */
PJ_DEF(pj_status_t) pjsua_vid_dev_get_setting( pjmedia_vid_dev_index id,
                                               pjmedia_vid_dev_cap cap,
                                               void *pval)
{
    pj_status_t status = PJ_SUCCESS;
    pjsua_vid_win_id wid;
    
    PJSUA_LOCK();
    wid = vid_preview_get_win(id, PJ_FALSE);    
    if (wid != PJSUA_INVALID_ID) {
        pjsua_vid_win *w;
        pjmedia_vid_dev_stream *cap_dev;

        w = &pjsua_var.win[wid];
        cap_dev = pjmedia_vid_port_get_stream(w->vp_cap);

        status = pjmedia_vid_dev_stream_get_cap(cap_dev, cap, pval);
        
        PJSUA_UNLOCK();
    } else {
        pjmedia_vid_dev_info info;
        
        PJSUA_UNLOCK();

        status = pjmedia_vid_dev_get_info(id, &info);
        if (status != PJ_SUCCESS)
            return status;
        
        /* Get real device ID, if set to default device */
        id = info.id;
    
        if ((pjsua_var.vid_caps[id] & cap) != 0) {
            status = pjmedia_vid_dev_param_get_cap(&pjsua_var.vid_param[id],
                                                   cap, pval);
        } else {
            status = PJ_ENOTFOUND;
        }
    }

    return status;
}

/*
 * Enum all video devices installed in the system.
 */
PJ_DEF(pj_status_t) pjsua_vid_enum_devs(pjmedia_vid_dev_info info[],
                                        unsigned *count)
{
    unsigned i, dev_count;

    dev_count = pjmedia_vid_dev_count();

    if (dev_count > *count) dev_count = *count;

    for (i=0; i<dev_count; ++i) {
        pj_status_t status;

        status = pjmedia_vid_dev_get_info(i, &info[i]);
        if (status != PJ_SUCCESS)
            return status;
    }

    *count = dev_count;

    return PJ_SUCCESS;
}


/*****************************************************************************
 * Codecs.
 */

static pj_status_t find_codecs_with_rtp_packing(
                                    const pj_str_t *codec_id,
                                    unsigned *count,
                                    const pjmedia_vid_codec_info *p_info[])
{
    const pjmedia_vid_codec_info *info[32];
    unsigned i, j, count_ = PJ_ARRAY_SIZE(info);
    pj_status_t status;
    
    status = pjmedia_vid_codec_mgr_find_codecs_by_id(NULL, codec_id,
                                                     &count_, info, NULL);
    if (status != PJ_SUCCESS)
        return status;

    for (i = 0, j = 0; i < count_ && j<*count; ++i) {
        if ((info[i]->packings & PJMEDIA_VID_PACKING_PACKETS) == 0)
            continue;
        p_info[j++] = info[i];
    }
    *count = j;
    return PJ_SUCCESS;
}

/*
 * Enum all supported video codecs in the system.
 */
PJ_DEF(pj_status_t) pjsua_vid_enum_codecs( pjsua_codec_info id[],
                                           unsigned *p_count )
{
    pjmedia_vid_codec_info info[32];
    unsigned i, j, count, prio[32];
    pj_status_t status;

    count = PJ_ARRAY_SIZE(info);
    status = pjmedia_vid_codec_mgr_enum_codecs(NULL, &count, info, prio);
    if (status != PJ_SUCCESS) {
        *p_count = 0;
        return status;
    }

    for (i=0, j=0; i<count && j<*p_count; ++i) {
        if (info[i].packings & PJMEDIA_VID_PACKING_PACKETS) {
            pj_bzero(&id[j], sizeof(pjsua_codec_info));

            pjmedia_vid_codec_info_to_id(&info[i], id[j].buf_, sizeof(id[j].buf_));
            id[j].codec_id = pj_str(id[j].buf_);
            id[j].priority = (pj_uint8_t) prio[i];

            if (id[j].codec_id.slen < sizeof(id[j].buf_)) {
                id[j].desc.ptr = id[j].codec_id.ptr + id[j].codec_id.slen + 1;
                pj_strncpy(&id[j].desc, &info[i].encoding_desc,
                           sizeof(id[j].buf_) - id[j].codec_id.slen - 1);
            }

            ++j;
        }
    }

    *p_count = j;

    return PJ_SUCCESS;
}


/*
 * Change video codec priority.
 */
PJ_DEF(pj_status_t) pjsua_vid_codec_set_priority( const pj_str_t *codec_id,
                                                  pj_uint8_t priority )
{
    const pj_str_t all = { NULL, 0 };

    if (codec_id->slen==1 && *codec_id->ptr=='*')
        codec_id = &all;

    return pjmedia_vid_codec_mgr_set_codec_priority(NULL, codec_id,
                                                    priority);
}


/*
 * Get video codec parameters.
 */
PJ_DEF(pj_status_t) pjsua_vid_codec_get_param(
                                        const pj_str_t *codec_id,
                                        pjmedia_vid_codec_param *param)
{
    const pjmedia_vid_codec_info *info[2];
    unsigned count = 2;
    pj_status_t status;

    status = find_codecs_with_rtp_packing(codec_id, &count, info);
    if (status != PJ_SUCCESS)
        return status;

    if (count != 1)
        return (count > 1? PJ_ETOOMANY : PJ_ENOTFOUND);

    status = pjmedia_vid_codec_mgr_get_default_param(NULL, info[0], param);
    return status;
}


/*
 * Set video codec parameters.
 */
PJ_DEF(pj_status_t) pjsua_vid_codec_set_param(
                                        const pj_str_t *codec_id,
                                        const pjmedia_vid_codec_param *param)
{
    const pjmedia_vid_codec_info *info[2];
    unsigned count = 2;
    pj_status_t status;

    status = find_codecs_with_rtp_packing(codec_id, &count, info);
    if (status != PJ_SUCCESS)
        return status;

    if (count != 1)
        return (count > 1? PJ_ETOOMANY : PJ_ENOTFOUND);

    status = pjmedia_vid_codec_mgr_set_default_param(NULL, info[0], param);
    return status;
}


/*****************************************************************************
 * Preview
 */

static pjsua_vid_win_id vid_preview_get_win(pjmedia_vid_dev_index id,
                                            pj_bool_t running_only)
{
    pjsua_vid_win_id wid = PJSUA_INVALID_ID;
    unsigned i;

    PJSUA_LOCK();

    /* Get real capture ID, if set to PJMEDIA_VID_DEFAULT_CAPTURE_DEV */
    if (id == PJMEDIA_VID_DEFAULT_CAPTURE_DEV) {
        pjmedia_vid_dev_info info;
        pjmedia_vid_dev_get_info(id, &info);
        id = info.id;
    }

    for (i=0; i<PJSUA_MAX_VID_WINS; ++i) {
        pjsua_vid_win *w = &pjsua_var.win[i];
        if (w->type == PJSUA_WND_TYPE_PREVIEW && w->preview_cap_id == id) {
            wid = i;
            break;
        }
    }

    if (wid != PJSUA_INVALID_ID && running_only) {
        pjsua_vid_win *w = &pjsua_var.win[wid];
        wid = w->preview_running ? wid : PJSUA_INVALID_ID;
    }

    PJSUA_UNLOCK();

    return wid;
}

/*
 * NOTE: internal function don't use this!!! Use vid_preview_get_win()
 *       instead. This is because this function will only return window ID
 *       if preview is currently running.
 */
PJ_DEF(pjsua_vid_win_id) pjsua_vid_preview_get_win(pjmedia_vid_dev_index id)
{
    return vid_preview_get_win(id, PJ_TRUE);
}

/*
 * Get video conference slot ID of the specified capture device.
 */
PJ_DEF(pjsua_conf_port_id) pjsua_vid_preview_get_vid_conf_port(
                                                    pjmedia_vid_dev_index id)
{
    pjsua_vid_win_id wid;
    pjsua_vid_win *w;
    pjsua_conf_port_id conf_id = PJSUA_INVALID_ID;

    PJSUA_LOCK();
    wid = vid_preview_get_win(id, PJ_TRUE);
    if (wid != PJSUA_INVALID_ID) {
        w = &pjsua_var.win[wid];
        conf_id = w->cap_slot;
    }
    PJSUA_UNLOCK();
    
    return conf_id;
}


void pjsua_vid_win_reset(pjsua_vid_win_id wid)
{
    pjsua_vid_win *w = &pjsua_var.win[wid];
    pj_pool_t *pool = w->pool;

    pj_bzero(w, sizeof(*w));
    if (pool) pj_pool_reset(pool);
    w->ref_cnt = 0;
    w->pool = pool;
    w->preview_cap_id = PJMEDIA_VID_INVALID_DEV;
}

/* Allocate and initialize pjsua video window:
 * - If the type is preview: capture port and render port
 *   will be instantiated, and connected via conf.
 * - If the type is stream: only render port will be created.
 */
static pj_status_t create_vid_win(pjsua_vid_win_type type,
                                  const pjmedia_format *fmt,
                                  pjmedia_vid_dev_index rend_id,
                                  pjmedia_vid_dev_index cap_id,
                                  pj_bool_t show,
                                  unsigned wnd_flags,
                                  const pjmedia_vid_dev_hwnd *wnd,
                                  pjsua_vid_win_id *id)
{
    pj_bool_t enable_native_preview;
    pjsua_vid_win_id wid = PJSUA_INVALID_ID;
    pjsua_vid_win *w = NULL;
    pjmedia_vid_port_param vp_param;
    pjmedia_format fmt_;
    pj_status_t status;
    unsigned i;

    enable_native_preview = pjsua_var.media_cfg.vid_preview_enable_native;

    PJ_LOG(4,(THIS_FILE,
              "Creating video window: type=%s, cap_id=%d, rend_id=%d",
              pjsua_vid_win_type_name(type), cap_id, rend_id));
    pj_log_push_indent();

    /* If type is preview, check if it exists already */
    if (type == PJSUA_WND_TYPE_PREVIEW) {
        wid = vid_preview_get_win(cap_id, PJ_FALSE);
        if (wid != PJSUA_INVALID_ID) {
            /* Yes, it exists */
            /* Show/hide window */
            pjmedia_vid_dev_stream *strm;
            pj_bool_t hide = !show;

            w = &pjsua_var.win[wid];

            PJ_LOG(4,(THIS_FILE,
                      "Window already exists for cap_dev=%d, returning wid=%d",
                      cap_id, wid));


            if (w->is_native) {
                strm = pjmedia_vid_port_get_stream(w->vp_cap);
            } else {
                strm = pjmedia_vid_port_get_stream(w->vp_rend);
            }
            pj_assert(strm);

            /* Try to apply show/hide, window flags, and output window */

            status = pjmedia_vid_dev_stream_set_cap(
                                strm, PJMEDIA_VID_DEV_CAP_OUTPUT_HIDE,
                                &hide);
            if (status != PJ_SUCCESS) {
                PJ_PERROR(4,(THIS_FILE, status,
                             "Ignored error on setting window visibility "
                             "on wid=%d", wid));
            }

            status = pjmedia_vid_dev_stream_set_cap(
                                strm, PJMEDIA_VID_DEV_CAP_OUTPUT_WINDOW_FLAGS,
                                &wnd_flags);
            if (status != PJ_SUCCESS) {
                PJ_PERROR(4,(THIS_FILE, status,
                             "Ignored error on setting window flags "
                             "on wid=%d", wid));
            }

            if (wnd) {
                status = pjmedia_vid_dev_stream_set_cap(
                                 strm, PJMEDIA_VID_DEV_CAP_OUTPUT_WINDOW, wnd);

                if (status != PJ_SUCCESS) {
                    PJ_PERROR(4, (THIS_FILE, status,
                                  "Ignored error on setting window handle "
                                  "on wid=%d", wid));
                }
            }

            status = pjsua_vid_conf_connect(w->cap_slot, w->rend_slot, NULL);
            if (status != PJ_SUCCESS) {
                PJ_PERROR(4, (THIS_FILE, status,
                              "Ignored error on connecting video ports "
                              "on wid=%d", wid));
            }

            /* Done */
            *id = wid;
            pj_log_pop_indent();

            return PJ_SUCCESS;
        }
    }

    /* Allocate window */
    for (i=0; i<PJSUA_MAX_VID_WINS; ++i) {
        w = &pjsua_var.win[i];
        if (w->type == PJSUA_WND_TYPE_NONE) {
            wid = i;
            w->type = type;
            break;
        }
    }
    if (i == PJSUA_MAX_VID_WINS) {
        pj_log_pop_indent();
        return PJ_ETOOMANY;
    }

    /* Initialize window */
    pjmedia_vid_port_param_default(&vp_param);

    if (w->type == PJSUA_WND_TYPE_PREVIEW) {
        pjmedia_vid_dev_info vdi;

        /*
         * Determine if the device supports native preview.
         */
        status = pjmedia_vid_dev_get_info(cap_id, &vdi);
        if (status != PJ_SUCCESS)
            goto on_error;

        if (enable_native_preview &&
             (vdi.caps & PJMEDIA_VID_DEV_CAP_INPUT_PREVIEW))
        {
            /* Device supports native preview! */
            w->is_native = PJ_TRUE;
        }

        status = pjmedia_vid_dev_default_param(w->pool, cap_id,
                                               &vp_param.vidparam);
        if (status != PJ_SUCCESS)
            goto on_error;

        if (w->is_native) {
            vp_param.vidparam.flags |= PJMEDIA_VID_DEV_CAP_OUTPUT_HIDE;
            vp_param.vidparam.window_hide = !show;
            vp_param.vidparam.flags |= PJMEDIA_VID_DEV_CAP_OUTPUT_WINDOW_FLAGS;
            vp_param.vidparam.window_flags = wnd_flags;
        }

        /* Normalize capture ID, in case it was set to
         * PJMEDIA_VID_DEFAULT_CAPTURE_DEV
         */
        cap_id = vp_param.vidparam.cap_id;

        /* Assign preview capture device ID */
        w->preview_cap_id = cap_id;

        /* Create capture video port */
        vp_param.active = PJ_FALSE;
        vp_param.vidparam.dir = PJMEDIA_DIR_CAPTURE;

        /* Update the video setting with user preference */
#define update_param(cap, field)    \
            if ((pjsua_var.vid_caps[cap_id] & cap) && (vdi.caps & cap)) { \
                vp_param.vidparam.flags |= cap; \
                pj_memcpy(&vp_param.vidparam.field, \
                          &pjsua_var.vid_param[cap_id].field, \
                          sizeof(vp_param.vidparam.field)); \
            }

        if (fmt) {
            vp_param.vidparam.fmt = *fmt;
        } else {
            update_param(PJMEDIA_VID_DEV_CAP_FORMAT, fmt);
        }
        
        update_param(PJMEDIA_VID_DEV_CAP_ORIENTATION, orient);

#undef update_param

        status = pjmedia_vid_port_create(w->pool, &vp_param, &w->vp_cap);
        if (status != PJ_SUCCESS)
            goto on_error;

        /* Update format info */
        fmt_ = vp_param.vidparam.fmt;
        fmt = &fmt_;

        /* Register capturer to the video conf */
        status = pjsua_vid_conf_add_port(
                                w->pool,
                                pjmedia_vid_port_get_passive_port(w->vp_cap),
                                NULL, &w->cap_slot);
        if (status != PJ_SUCCESS)
            goto on_error;

        /* If device supports native preview, enable it */
        if (w->is_native) {
            pjmedia_vid_dev_stream *cap_dev;
            pj_bool_t enabled = PJ_TRUE;

            cap_dev = pjmedia_vid_port_get_stream(w->vp_cap);
            status = pjmedia_vid_dev_stream_set_cap(
                            cap_dev, PJMEDIA_VID_DEV_CAP_INPUT_PREVIEW,
                            &enabled);
            if (status != PJ_SUCCESS) {
                pjsua_perror(THIS_FILE,
                             "Error activating native preview, falling back "
                             "to software preview..",
                             status);
                w->is_native = PJ_FALSE;
            }
        }
    }

    /* Create renderer video port, only if it's not a native preview */
    if (!w->is_native) {
        status = pjmedia_vid_dev_default_param(w->pool, rend_id,
                                               &vp_param.vidparam);
        if (status != PJ_SUCCESS)
            goto on_error;

        vp_param.active = PJ_FALSE;
        vp_param.vidparam.dir = PJMEDIA_DIR_RENDER;
        vp_param.vidparam.fmt = *fmt;
        vp_param.vidparam.disp_size = fmt->det.vid.size;
        vp_param.vidparam.flags |= PJMEDIA_VID_DEV_CAP_OUTPUT_HIDE;
        vp_param.vidparam.window_hide = !show;
        vp_param.vidparam.flags |= PJMEDIA_VID_DEV_CAP_OUTPUT_WINDOW_FLAGS;
        vp_param.vidparam.window_flags = wnd_flags;
        if (wnd) {
            vp_param.vidparam.flags |= PJMEDIA_VID_DEV_CAP_OUTPUT_WINDOW;
            vp_param.vidparam.window = *wnd;
        }

        status = pjmedia_vid_port_create(w->pool, &vp_param, &w->vp_rend);
        if (status != PJ_SUCCESS)
            goto on_error;

        /* Register renderer to the video conf */
        status = pjsua_vid_conf_add_port(
                                w->pool,
                                pjmedia_vid_port_get_passive_port(w->vp_rend),
                                NULL, &w->rend_slot);
        if (status != PJ_SUCCESS)
            goto on_error;

        /* For preview window, connect capturer & renderer (via conf) */
        if (w->type == PJSUA_WND_TYPE_PREVIEW && show) {
            status = pjsua_vid_conf_connect(w->cap_slot, w->rend_slot, NULL);
            if (status != PJ_SUCCESS)
                goto on_error;
        }

        PJ_LOG(4,(THIS_FILE,
                  "%s window id %d created for cap_dev=%d rend_dev=%d",
                  pjsua_vid_win_type_name(type), wid, cap_id, rend_id));
    } else {
        PJ_LOG(4,(THIS_FILE,
                  "Preview window id %d created for cap_dev %d, "
                  "using built-in preview!",
                  wid, cap_id));
    }


    /* Done */
    *id = wid;

    PJ_LOG(4,(THIS_FILE, "Window %d created", wid));
    pj_log_pop_indent();
    return PJ_SUCCESS;

on_error:
    free_vid_win(wid);
    pj_log_pop_indent();
    return status;
}


static void free_vid_win(pjsua_vid_win_id wid)
{
    pjsua_vid_win *w = &pjsua_var.win[wid];
    unsigned num_locks = 0;
    
    PJ_LOG(4,(THIS_FILE, "Window %d: destroying..", wid));
    pj_log_push_indent();

    /* Release locks before unsubscribing/destroying, to avoid deadlock. */
    num_locks = PJSUA_RELEASE_LOCK();

    if (w->vp_cap) {
        pjsua_vid_conf_remove_port(w->cap_slot);
        pjmedia_event_unsubscribe(NULL, &call_media_on_event, NULL,
                                  w->vp_cap);
        pjmedia_vid_port_stop(w->vp_cap);
        pjmedia_vid_port_destroy(w->vp_cap);
    }
    if (w->vp_rend) {
        pjsua_vid_conf_remove_port(w->rend_slot);
        pjmedia_event_unsubscribe(NULL, &call_media_on_event, NULL,
                                  w->vp_rend);
        pjmedia_vid_port_stop(w->vp_rend);
        pjmedia_vid_port_destroy(w->vp_rend);
    }
    /* Re-acquire the locks. */
    PJSUA_RELOCK(num_locks);

    pjsua_vid_win_reset(wid);

    pj_log_pop_indent();
}


static void inc_vid_win(pjsua_vid_win_id wid)
{
    pjsua_vid_win *w;
    
    pj_assert(wid >= 0 && wid < PJSUA_MAX_VID_WINS);

    w = &pjsua_var.win[wid];
    pj_assert(w->type != PJSUA_WND_TYPE_NONE);
    ++w->ref_cnt;
}

static void dec_vid_win(pjsua_vid_win_id wid)
{
    pjsua_vid_win *w;
    
    pj_assert(wid >= 0 && wid < PJSUA_MAX_VID_WINS);

    w = &pjsua_var.win[wid];
    pj_assert(w->type != PJSUA_WND_TYPE_NONE);
    if (--w->ref_cnt == 0)
        free_vid_win(wid);
}

/* Initialize video call media */
pj_status_t pjsua_vid_channel_init(pjsua_call_media *call_med)
{
    pjsua_acc *acc = &pjsua_var.acc[call_med->call->acc_id];

    call_med->strm.v.rdr_dev = acc->cfg.vid_rend_dev;
    call_med->strm.v.cap_dev = acc->cfg.vid_cap_dev;
    call_med->strm.v.strm_dec_slot = PJSUA_INVALID_ID;
    call_med->strm.v.strm_enc_slot = PJSUA_INVALID_ID;
    /*
     * pjmedia_vid_dev_get_info() will raise assertion when video device
     * subsys initialization is delayed (see PJSUA_DONT_INIT_VID_DEV_SUBSYS
     * or #2777). While normalizing default device IDs is not urgent
     * at this point.

    if (call_med->strm.v.rdr_dev == PJMEDIA_VID_DEFAULT_RENDER_DEV) {
        pjmedia_vid_dev_info info;
        pjmedia_vid_dev_get_info(call_med->strm.v.rdr_dev, &info);
        call_med->strm.v.rdr_dev = info.id;
    }
    if (call_med->strm.v.cap_dev == PJMEDIA_VID_DEFAULT_CAPTURE_DEV) {
        pjmedia_vid_dev_info info;
        pjmedia_vid_dev_get_info(call_med->strm.v.cap_dev, &info);
        call_med->strm.v.cap_dev = info.id;
    }
    */

    return PJ_SUCCESS;
}

static pj_status_t setup_vid_capture(pjsua_call_media *call_med)
{
    pjsua_acc *acc_enc = &pjsua_var.acc[call_med->call->acc_id];
    pjmedia_port *media_port;
    pjsua_vid_win *w;
    pjsua_vid_win_id wid;
    pj_bool_t just_created = PJ_FALSE;
    pj_status_t status;

    /* Retrieve stream encoding port */
    status = pjmedia_vid_stream_get_port(call_med->strm.v.stream,
                                         PJMEDIA_DIR_ENCODING,
                                         &media_port);
    if (status != PJ_SUCCESS)
        return status;

    PJSUA_LOCK();

    /* Note: calling pjsua_vid_preview_get_win() even though
     * create_vid_win() will automatically create the window
     * if it doesn't exist, because create_vid_win() will modify
     * existing window SHOW/HIDE value.
     */
    wid = vid_preview_get_win(call_med->strm.v.cap_dev, PJ_FALSE);
    if (wid == PJSUA_INVALID_ID) {
        /* Create preview video window */
        status = create_vid_win(PJSUA_WND_TYPE_PREVIEW,
                                &media_port->info.fmt,
                                call_med->strm.v.rdr_dev,
                                call_med->strm.v.cap_dev,
                                PJSUA_HIDE_WINDOW,
                                acc_enc->cfg.vid_wnd_flags,
                                NULL,
                                &wid);
        if (status != PJ_SUCCESS)
            goto on_error;

        just_created = PJ_TRUE;
    }

    w = &pjsua_var.win[wid];
#if ENABLE_EVENT
    pjmedia_event_subscribe(NULL, &call_media_on_event,
                            call_med, w->vp_cap);
#endif

    /* Connect capturer to stream encoding (via conf) */
    status = pjsua_vid_conf_connect(w->cap_slot,
                                    call_med->strm.v.strm_enc_slot,
                                    NULL);
    if (status != PJ_SUCCESS)
        goto on_error;

    /* Start capturer */
    if (just_created) {
        status = pjmedia_vid_port_start(w->vp_cap);
        if (status != PJ_SUCCESS)
            goto on_error;
    }

    /* Done */
    inc_vid_win(wid);
    call_med->strm.v.cap_win_id = wid;
    PJ_LOG(4,(THIS_FILE, "Call %d media %d: video capture set up with "
                         "dev %d, wid=%d", call_med->call->index,
                         call_med->idx, call_med->strm.v.cap_dev, wid));

    PJSUA_UNLOCK();

    return PJ_SUCCESS;

on_error:
    PJSUA_UNLOCK();
    return status;
}

/* Internal function: update video channel after SDP negotiation.
 * Warning: do not use temporary/flip-flop pool, e.g: inv->pool_prov,
 *          for creating stream, etc, as after SDP negotiation and when
 *          the SDP media is not changed, the stream should remain running
 *          while the temporary/flip-flop pool may be released.
 */
pj_status_t pjsua_vid_channel_update(pjsua_call_media *call_med,
                                     pj_pool_t *tmp_pool,
                                     pjmedia_vid_stream_info *si,
                                     const pjmedia_sdp_session *local_sdp,
                                     const pjmedia_sdp_session *remote_sdp)
{
    pjsua_call *call = call_med->call;
    unsigned strm_idx = call_med->idx;
    pjsua_acc  *acc  = &pjsua_var.acc[call->acc_id];    
    pjmedia_port *media_port;
    pj_status_t status;
 
    PJ_UNUSED_ARG(tmp_pool);
    PJ_UNUSED_ARG(local_sdp);
    PJ_UNUSED_ARG(remote_sdp);

    PJ_LOG(4,(THIS_FILE, "Video channel update.."));
    pj_log_push_indent();

    si->rtcp_sdes_bye_disabled = pjsua_var.media_cfg.no_rtcp_sdes_bye;;

    /* Check if no media is active */
    if (local_sdp->media[strm_idx]->desc.port != 0) {
        /* Optionally, application may modify other stream settings here
         * (such as jitter buffer parameters, codec ptime, etc.)
         */
        si->jb_init = pjsua_var.media_cfg.jb_init;
        si->jb_min_pre = pjsua_var.media_cfg.jb_min_pre;
        si->jb_max_pre = pjsua_var.media_cfg.jb_max_pre;
        si->jb_max = pjsua_var.media_cfg.jb_max;

        /* Set SSRC and CNAME */
        si->ssrc = call_med->ssrc;
        si->cname = call->cname;

        /* Set RTP timestamp & sequence, normally these value are intialized
         * automatically when stream session created, but for some cases (e.g:
         * call reinvite, call update) timestamp and sequence need to be kept
         * contigue.
         */
        si->rtp_ts = call_med->rtp_tx_ts;
        si->rtp_seq = call_med->rtp_tx_seq;
        si->rtp_seq_ts_set = call_med->rtp_tx_seq_ts_set;

        /* Set rate control config from account setting */
        si->rc_cfg = acc->cfg.vid_stream_rc_cfg;

        /* Set send keyframe config from account setting */
        si->sk_cfg = acc->cfg.vid_stream_sk_cfg;

#if defined(PJMEDIA_STREAM_ENABLE_KA) && PJMEDIA_STREAM_ENABLE_KA!=0
        /* Enable/disable stream keep-alive and NAT hole punch. */
        si->use_ka = acc->cfg.use_stream_ka;

        si->ka_cfg = acc->cfg.stream_ka_cfg;
#endif

        /* Try to get shared format ID between the capture device and 
         * the encoder to avoid format conversion in the capture device.
         */
        if (si->dir & PJMEDIA_DIR_ENCODING) {
            pjmedia_vid_dev_info dev_info;
            pjmedia_vid_codec_info *codec_info = &si->codec_info;
            unsigned i, j;

            status = pjmedia_vid_dev_get_info(call_med->strm.v.cap_dev,
                                              &dev_info);
            if (status != PJ_SUCCESS)
                goto on_error;

            /* Find matched format ID */
            for (i = 0; i < codec_info->dec_fmt_id_cnt; ++i) {
                for (j = 0; j < dev_info.fmt_cnt; ++j) {
                    if (codec_info->dec_fmt_id[i] == 
                        (pjmedia_format_id)dev_info.fmt[j].id)
                    {
                        /* Apply the matched format ID to the codec */
                        si->codec_param->dec_fmt.id = 
                                                codec_info->dec_fmt_id[i];

                        /* Force outer loop to break */
                        i = codec_info->dec_fmt_id_cnt;
                        break;
                    }
                }
            }
        }

        if (!call->hanging_up && pjsua_var.ua_cfg.cb.on_stream_precreate) {
            pjsua_on_stream_precreate_param prm;
            prm.stream_idx = strm_idx;
            prm.stream_info.type = PJMEDIA_TYPE_VIDEO;
            prm.stream_info.info.vid = *si;
            (*pjsua_var.ua_cfg.cb.on_stream_precreate)(call->index, &prm);

            /* Copy back only the fields which are allowed to be changed. */
            si->jb_init = prm.stream_info.info.vid.jb_init;
            si->jb_min_pre = prm.stream_info.info.vid.jb_min_pre;
            si->jb_max_pre = prm.stream_info.info.vid.jb_max_pre;
            si->jb_max = prm.stream_info.info.vid.jb_max;
#if defined(PJMEDIA_STREAM_ENABLE_KA) && (PJMEDIA_STREAM_ENABLE_KA != 0)
            si->use_ka = prm.stream_info.info.vid.use_ka;
#endif
            si->rtcp_sdes_bye_disabled = prm.stream_info.info.vid.rtcp_sdes_bye_disabled;
            si->codec_param->enc_fmt = prm.stream_info.info.vid.codec_param->enc_fmt;
        }

        /* Create session based on session info. */
        status = pjmedia_vid_stream_create(pjsua_var.med_endpt, NULL, si,
                                           call_med->tp, NULL,
                                           &call_med->strm.v.stream);
        if (status != PJ_SUCCESS)
            goto on_error;

        /* Subscribe to video stream events */
        pjmedia_event_subscribe(NULL, &call_media_on_event,
                                call_med, call_med->strm.v.stream);

        /* Start stream */
        status = pjmedia_vid_stream_start(call_med->strm.v.stream);
        if (status != PJ_SUCCESS)
            goto on_error;

        if (call_med->prev_state == PJSUA_CALL_MEDIA_NONE)
            pjmedia_vid_stream_send_rtcp_sdes(call_med->strm.v.stream);

        /* Setup decoding direction */
        if (si->dir & PJMEDIA_DIR_DECODING)
        {
            pjsua_vid_win_id wid;
            pjsua_vid_win *w;

            PJ_LOG(4,(THIS_FILE, "Setting up RX.."));
            pj_log_push_indent();

            /* Retrieve stream decoding port */
            status = pjmedia_vid_stream_get_port(call_med->strm.v.stream,
                                                 PJMEDIA_DIR_DECODING,
                                                 &media_port);
            if (status != PJ_SUCCESS) {
                pj_log_pop_indent();
                goto on_error;
            }

            /* Create stream video window */
            PJSUA_LOCK();
            status = create_vid_win(PJSUA_WND_TYPE_STREAM,
                                    &media_port->info.fmt,
                                    call_med->strm.v.rdr_dev,
                                    //acc->cfg.vid_rend_dev,
                                    PJSUA_INVALID_ID,
                                    acc->cfg.vid_in_auto_show,
                                    acc->cfg.vid_wnd_flags,
                                    NULL,
                                    &wid);
            if (status != PJ_SUCCESS) {
                PJSUA_UNLOCK();
                pj_log_pop_indent();
                goto on_error;
            }

            w = &pjsua_var.win[wid];

#if ENABLE_EVENT
            /* Register to video events */
            pjmedia_event_subscribe(NULL, &call_media_on_event,
                                    call_med, w->vp_rend);
            pjmedia_event_subscribe(NULL, &call_media_on_event,
                                    call_med, media_port);
#endif
            
            /* Register renderer to stream events */
            pjmedia_vid_port_subscribe_event(w->vp_rend, media_port);

            /* Register stream decoding to conf, using tmp_pool should be fine
             * as bridge will create its own pool (using tmp_pool factory).
             */
            status = pjsua_vid_conf_add_port(tmp_pool, media_port, NULL,
                                             &call_med->strm.v.strm_dec_slot);
            if (status != PJ_SUCCESS) {
                PJSUA_UNLOCK();
                pj_log_pop_indent();
                goto on_error;
            }

            /* Connect stream to renderer (via conf) */
            status = pjsua_vid_conf_connect(call_med->strm.v.strm_dec_slot,
                                            w->rend_slot, NULL);
            if (status != PJ_SUCCESS) {
                PJSUA_UNLOCK();
                pj_log_pop_indent();
                goto on_error;
            }

            /* Start renderer */
            status = pjmedia_vid_port_start(w->vp_rend);
            if (status != PJ_SUCCESS) {
                PJSUA_UNLOCK();
                pj_log_pop_indent();
                goto on_error;
            }

            /* Done */
            inc_vid_win(wid);
            call_med->strm.v.rdr_win_id = wid;
            PJSUA_UNLOCK();
            pj_log_pop_indent();
        }

        /* Retrieve stream encoding port */
        status = pjmedia_vid_stream_get_port(call_med->strm.v.stream,
                                             PJMEDIA_DIR_ENCODING,
                                             &media_port);
        if (status != PJ_SUCCESS)
            goto on_error;

        /* Register stream encoding to conf, using tmp_pool should be fine
         * as bridge will create its own pool (using tmp_pool factory).
         */
        status = pjsua_vid_conf_add_port(tmp_pool, media_port, NULL,
                                         &call_med->strm.v.strm_enc_slot);
        if (status != PJ_SUCCESS)
            goto on_error;

        /* Setup encoding direction */
        if (si->dir & PJMEDIA_DIR_ENCODING) {
            PJ_LOG(4,(THIS_FILE, "Setting up TX.."));
            pj_log_push_indent();

            if (!call->local_hold && acc->cfg.vid_out_auto_transmit) {
                status = setup_vid_capture(call_med);
                if (status != PJ_SUCCESS)
                    goto on_error;
            }

            pj_log_pop_indent();
        }
    }

    if (!acc->cfg.vid_out_auto_transmit && call_med->strm.v.stream) {
        status = pjmedia_vid_stream_pause(call_med->strm.v.stream,
                                          PJMEDIA_DIR_ENCODING);
        if (status != PJ_SUCCESS)
            goto on_error;
    }

    pj_log_pop_indent();
    return PJ_SUCCESS;

on_error:
    pj_log_pop_indent();
    return status;
}


/* Internal function to stop video stream */
void pjsua_vid_stop_stream(pjsua_call_media *call_med)
{
    pjmedia_vid_stream *strm = call_med->strm.v.stream;
    pjmedia_rtcp_stat stat;
    unsigned num_locks = 0;

    pj_assert(call_med->type == PJMEDIA_TYPE_VIDEO);

    if (!strm)
        return;

    PJ_LOG(4,(THIS_FILE, "Stopping video stream.."));
    pj_log_push_indent();
    
    pjmedia_vid_stream_get_info(strm, &call_med->prev_vid_si);

    pjmedia_vid_stream_send_rtcp_bye(strm);

    /* Release locks before unsubscribing, to avoid deadlock. */
    while (PJSUA_LOCK_IS_LOCKED()) {
        num_locks++;
        PJSUA_UNLOCK();
    }

    /* Unsubscribe events first, otherwise the event callbacks
     * can be called and access already destroyed objects.
     */
    if (call_med->strm.v.cap_win_id != PJSUA_INVALID_ID) {
        pjsua_vid_win *w = &pjsua_var.win[call_med->strm.v.cap_win_id];

        /* Unsubscribe event */
        pjmedia_event_unsubscribe(NULL, &call_media_on_event, call_med,
                                  w->vp_cap);
    }
    if (call_med->strm.v.rdr_win_id != PJSUA_INVALID_ID) {
        pj_status_t status;
        pjmedia_port *media_port;
        pjsua_vid_win *w = &pjsua_var.win[call_med->strm.v.rdr_win_id];

        /* Unsubscribe event, but stop the render first */
        pjmedia_vid_port_stop(w->vp_rend);
        pjmedia_event_unsubscribe(NULL, &call_media_on_event, call_med,
                                  w->vp_rend);

        /* Retrieve stream decoding port */
        status = pjmedia_vid_stream_get_port(strm, PJMEDIA_DIR_DECODING,
                                             &media_port);
        if (status == PJ_SUCCESS) {
            pjmedia_event_unsubscribe(NULL, &call_media_on_event,
                                    call_med, media_port);

            pjmedia_vid_port_unsubscribe_event(w->vp_rend, media_port);
        }
    }
    /* Unsubscribe from video stream events */
    pjmedia_event_unsubscribe(NULL, &call_media_on_event, call_med, strm);

    /* Re-acquire the locks. */
    for (; num_locks > 0; num_locks--)
        PJSUA_LOCK();

    PJSUA_LOCK();

    /* Now that we have unsubscribed from all events, we no longer
     * receive future events. But we may have scheduled some timers
     * to call media event callbacks, so we need to wait until those
     * complete. Note that we can't cancel those timers since timer
     * implementation doesn't guarantee there's no race between
     * entry cancellation and the callback being called from poll.
     */
    while (1) {
        pjsua_timer_list *act_timer;

        act_timer = pjsua_var.active_timer_list.next;
        while (act_timer != &pjsua_var.active_timer_list) {
            if (act_timer->cb == &call_med_event_cb) {
                pjsua_event_list *eve;
                
                eve = (pjsua_event_list *)act_timer->user_data;

                if (eve->call_id == (int)call_med->call->index &&
                    eve->med_idx == call_med->idx)
                {
                    pjsip_dialog *dlg = call_med->call->inv ?
                                            call_med->call->inv->dlg : NULL;

                    /* The function may be called from worker thread, we have
                     * to handle the events instead of simple sleep here
                     * and must not hold any lock while handling the events:
                     * https://github.com/pjsip/pjproject/issues/1737
                     */
                    num_locks = PJSUA_RELEASE_LOCK();

                    if (dlg) {
                        pjsip_dlg_inc_session(dlg, &pjsua_var.mod);
                        pjsip_dlg_dec_lock(dlg);
                    }

                    pjsua_handle_events(10);

                    if (dlg) {
                        pjsip_dlg_inc_lock(dlg);
                        pjsip_dlg_dec_session(dlg, &pjsua_var.mod);
                    }

                    PJSUA_RELOCK(num_locks);
                    break;
                }
            }
            act_timer = act_timer->next;            
        }
        if (act_timer == &pjsua_var.active_timer_list)
            break;
    }

    if (call_med->strm.v.cap_win_id != PJSUA_INVALID_ID) {
        /* Decrement ref count of preview video window */
        dec_vid_win(call_med->strm.v.cap_win_id);
        call_med->strm.v.cap_win_id = PJSUA_INVALID_ID;
        
        PJ_LOG(4,(THIS_FILE, "Call %d media %d: Preview video window "
                             "released", call_med->call->index,
                             call_med->idx));
    }

    if (call_med->strm.v.rdr_win_id != PJSUA_INVALID_ID) {
        /* Decrement ref count of stream video window */
        dec_vid_win(call_med->strm.v.rdr_win_id);
        call_med->strm.v.rdr_win_id = PJSUA_INVALID_ID;

        PJ_LOG(4,(THIS_FILE, "Call %d media %d: Stream video window "
                             "released", call_med->call->index,
                             call_med->idx));
    }
    PJSUA_UNLOCK();

    /* Unregister video stream ports (encode+decode) from conference */
    if (call_med->strm.v.strm_enc_slot != PJSUA_INVALID_ID) {
        pjsua_vid_conf_remove_port(call_med->strm.v.strm_enc_slot);
        call_med->strm.v.strm_enc_slot = PJSUA_INVALID_ID;
    }
    if (call_med->strm.v.strm_dec_slot != PJSUA_INVALID_ID) {
        pjsua_vid_conf_remove_port(call_med->strm.v.strm_dec_slot);
        call_med->strm.v.strm_dec_slot = PJSUA_INVALID_ID;
    }

    /* Don't check for direction and transmitted packets count as we
     * assume that RTP timestamp remains increasing when outgoing
     * direction is disabled/paused.
     */
     //if ((call_med->dir & PJMEDIA_DIR_ENCODING) &&
     //    (pjmedia_vid_stream_get_stat(strm, &stat) == PJ_SUCCESS) &&
     //    stat.tx.pkt)
    if (pjmedia_vid_stream_get_stat(strm, &stat) == PJ_SUCCESS)
    {
        /* Save RTP timestamp & sequence, so when media session is
         * restarted, those values will be restored as the initial
         * RTP timestamp & sequence of the new media session. So in
         * the same call session, RTP timestamp and sequence are
         * guaranteed to be contigue.
         */
        call_med->rtp_tx_seq_ts_set = 1 | (1 << 1);
        call_med->rtp_tx_seq = stat.rtp_tx_last_seq;
        call_med->rtp_tx_ts = stat.rtp_tx_last_ts;
    }

    pjmedia_vid_stream_destroy(strm);
    call_med->strm.v.stream = NULL;

    pj_log_pop_indent();
}

/*
 * Does it have built-in preview support.
 */
PJ_DEF(pj_bool_t) pjsua_vid_preview_has_native(pjmedia_vid_dev_index id)
{
    pjmedia_vid_dev_info vdi;

    return (pjmedia_vid_dev_get_info(id, &vdi)==PJ_SUCCESS) ?
            ((vdi.caps & PJMEDIA_VID_DEV_CAP_INPUT_PREVIEW)!=0) : PJ_FALSE;
}

/*
 * Start video preview window for the specified capture device.
 */
PJ_DEF(pj_status_t) pjsua_vid_preview_start(pjmedia_vid_dev_index id,
                                            const pjsua_vid_preview_param *prm)
{
    pjsua_vid_win_id wid;
    pjsua_vid_win *w;
    pjmedia_vid_dev_index rend_id;
    pjsua_vid_preview_param default_param;
    const pjmedia_format *fmt = NULL;
    pj_status_t status;

    if (!prm) {
        pjsua_vid_preview_param_default(&default_param);
        prm = &default_param;
    }

    PJ_LOG(4,(THIS_FILE, "Starting preview for cap_dev=%d, show=%d",
              id, prm->show));
    pj_log_push_indent();

    PJSUA_LOCK();

    rend_id = prm->rend_id;

    if (prm->format.detail_type == PJMEDIA_FORMAT_DETAIL_VIDEO)
        fmt = &prm->format;
    status = create_vid_win(PJSUA_WND_TYPE_PREVIEW, fmt, rend_id, id,
                            prm->show, prm->wnd_flags,
                            (prm->wnd.info.window? &prm->wnd: NULL), &wid);
    if (status != PJ_SUCCESS) {
        PJSUA_UNLOCK();
        pj_log_pop_indent();
        return status;
    }

    w = &pjsua_var.win[wid];
    if (w->preview_running) {
        PJSUA_UNLOCK();
        pj_log_pop_indent();
        return PJ_SUCCESS;
    }

    /* Start renderer, unless it's native preview */
    if (w->is_native && !pjmedia_vid_port_is_running(w->vp_cap)) {
        pjmedia_vid_dev_stream *cap_dev;
        pj_bool_t enabled = PJ_TRUE;

        cap_dev = pjmedia_vid_port_get_stream(w->vp_cap);
        status = pjmedia_vid_dev_stream_set_cap(
                        cap_dev, PJMEDIA_VID_DEV_CAP_INPUT_PREVIEW,
                        &enabled);
        if (status != PJ_SUCCESS) {
            pjsua_perror(THIS_FILE,
                         "Error activating native preview, falling back "
                         "to software preview..",
                         status);
            w->is_native = PJ_FALSE;
        }
    }

    if (!w->is_native && !pjmedia_vid_port_is_running(w->vp_rend)) {
        status = pjmedia_vid_port_start(w->vp_rend);
        if (status != PJ_SUCCESS) {
            PJSUA_UNLOCK();
            pj_log_pop_indent();
            return status;
        }
    }

    /* Start capturer */
    if (!pjmedia_vid_port_is_running(w->vp_cap)) {
        status = pjmedia_vid_port_start(w->vp_cap);
        if (status != PJ_SUCCESS) {
            PJSUA_UNLOCK();
            pj_log_pop_indent();
            return status;
        }
    }

    inc_vid_win(wid);
    w->preview_running = PJ_TRUE;

    PJSUA_UNLOCK();
    pj_log_pop_indent();
    return PJ_SUCCESS;
}

/*
 * Stop video preview.
 */
PJ_DEF(pj_status_t) pjsua_vid_preview_stop(pjmedia_vid_dev_index id)
{
    pjsua_vid_win_id wid = PJSUA_INVALID_ID;
    pjsua_vid_win *w;
    pj_status_t status;

    PJSUA_LOCK();
    wid = pjsua_vid_preview_get_win(id);
    if (wid == PJSUA_INVALID_ID) {
        PJSUA_UNLOCK();
        return PJ_ENOTFOUND;
    }

    PJ_LOG(4,(THIS_FILE, "Stopping preview for cap_dev=%d", id));
    pj_log_push_indent();

    w = &pjsua_var.win[wid];
    if (w->preview_running) {
        if (w->is_native) {
            pjmedia_vid_dev_stream *cap_dev;
            pj_bool_t enabled = PJ_FALSE;

            cap_dev = pjmedia_vid_port_get_stream(w->vp_cap);
            status = pjmedia_vid_dev_stream_set_cap(
                            cap_dev, PJMEDIA_VID_DEV_CAP_INPUT_PREVIEW,
                            &enabled);
        } else {
            status = pjsua_vid_conf_disconnect(w->cap_slot, w->rend_slot);
            if (status != PJ_SUCCESS) {
                PJ_PERROR(4, (THIS_FILE, status,
                              "Ignored error on disconnecting video ports "
                              "on stopping preview wid=%d", wid));
            }
            status = pjmedia_vid_port_stop(w->vp_rend);
        }

        if (status != PJ_SUCCESS) {
            PJ_PERROR(1,(THIS_FILE, status, "Error stopping %spreview",
                         (w->is_native ? "native " : "")));
            PJSUA_UNLOCK();
            pj_log_pop_indent();
            return status;
        }

        dec_vid_win(wid);
        w->preview_running = PJ_FALSE;
    }

    PJSUA_UNLOCK();
    pj_log_pop_indent();

    return PJ_SUCCESS;
}


/*****************************************************************************
 * Window
 */


/*
 * Enumerates all video windows.
 */
PJ_DEF(pj_status_t) pjsua_vid_enum_wins( pjsua_vid_win_id wids[],
                                         unsigned *count)
{
    unsigned i, cnt;

    cnt = 0;

    for (i=0; i<PJSUA_MAX_VID_WINS && cnt <*count; ++i) {
        pjsua_vid_win *w = &pjsua_var.win[i];
        if (w->type != PJSUA_WND_TYPE_NONE)
            wids[cnt++] = i;
    }

    *count = cnt;

    return PJ_SUCCESS;
}


/*
 * Get window info.
 */
PJ_DEF(pj_status_t) pjsua_vid_win_get_info( pjsua_vid_win_id wid,
                                            pjsua_vid_win_info *wi)
{
    pjsua_vid_win *w;
    pjmedia_vid_dev_stream *s;
    pjmedia_vid_dev_param vparam;
    pj_status_t status;

    PJ_ASSERT_RETURN(wid >= 0 && wid < PJSUA_MAX_VID_WINS && wi, PJ_EINVAL);

    pj_bzero(wi, sizeof(*wi));

    PJSUA_LOCK();
    w = &pjsua_var.win[wid];
    
    wi->is_native = w->is_native;

    if (w->is_native) {
        pjmedia_vid_dev_stream *cap_strm;
        pjmedia_vid_dev_cap cap = PJMEDIA_VID_DEV_CAP_OUTPUT_WINDOW;

        if (!w->vp_cap) {
            status = PJ_EINVAL;
        } else {
            cap_strm = pjmedia_vid_port_get_stream(w->vp_cap);
            if (!cap_strm) {
                status = PJ_EINVAL;
            } else {
                status = pjmedia_vid_dev_stream_get_cap(cap_strm, cap, 
                                                        &wi->hwnd);
            }
        }
        PJSUA_UNLOCK();
        return status;
    }

    if (w->vp_rend == NULL) {
        PJSUA_UNLOCK();
        return PJ_EINVAL;
    }

    s = pjmedia_vid_port_get_stream(w->vp_rend);
    if (s == NULL) {
        PJSUA_UNLOCK();
        return PJ_EINVAL;
    }

    status = pjmedia_vid_dev_stream_get_param(s, &vparam);
    if (status != PJ_SUCCESS) {
        PJSUA_UNLOCK();
        return status;
    }

    wi->rdr_dev = vparam.rend_id;
    wi->slot_id = w->rend_slot;
    wi->hwnd = vparam.window;
    wi->show = !vparam.window_hide;
    wi->pos  = vparam.window_pos;
    wi->size = vparam.disp_size;

    PJSUA_UNLOCK();

    return PJ_SUCCESS;
}

/*
 * Show or hide window.
 */
PJ_DEF(pj_status_t) pjsua_vid_win_set_show( pjsua_vid_win_id wid,
                                            pj_bool_t show)
{
    pjsua_vid_win *w;
    pjmedia_vid_dev_stream *s;
    pj_bool_t hide;
    pj_status_t status;

    PJ_ASSERT_RETURN(wid >= 0 && wid < PJSUA_MAX_VID_WINS, PJ_EINVAL);

    PJSUA_LOCK();

    w = &pjsua_var.win[wid];
    s = pjmedia_vid_port_get_stream(w->vp_rend? w->vp_rend: w->vp_cap);
    if (s == NULL) {
        PJSUA_UNLOCK();
        return PJ_EINVAL;
    }

    /* Make sure that renderer gets started before shown up */
    if (show && !pjmedia_vid_port_is_running(w->vp_rend))
        status = pjmedia_vid_port_start(w->vp_rend);

    hide = !show;
    status = pjmedia_vid_dev_stream_set_cap(s,
                            PJMEDIA_VID_DEV_CAP_OUTPUT_HIDE, &hide);

    PJSUA_UNLOCK();

    return status;
}

/*
 * Set video window position.
 */
PJ_DEF(pj_status_t) pjsua_vid_win_set_pos( pjsua_vid_win_id wid,
                                           const pjmedia_coord *pos)
{
    pjsua_vid_win *w;
    pjmedia_vid_dev_stream *s;
    pj_status_t status;

    PJ_ASSERT_RETURN(wid >= 0 && wid < PJSUA_MAX_VID_WINS && pos, PJ_EINVAL);

    PJSUA_LOCK();

    w = &pjsua_var.win[wid];
    s = pjmedia_vid_port_get_stream(w->vp_rend? w->vp_rend: w->vp_cap);
    if (s == NULL) {
        PJSUA_UNLOCK();
        return PJ_EINVAL;
    }

    status = pjmedia_vid_dev_stream_set_cap(s,
                            PJMEDIA_VID_DEV_CAP_OUTPUT_POSITION, pos);

    PJSUA_UNLOCK();

    return status;
}

/*
 * Resize window.
 */
PJ_DEF(pj_status_t) pjsua_vid_win_set_size( pjsua_vid_win_id wid,
                                            const pjmedia_rect_size *size)
{
    pjsua_vid_win *w;
    pjmedia_vid_dev_stream *s;
    pj_status_t status;

    PJ_ASSERT_RETURN(wid >= 0 && wid < PJSUA_MAX_VID_WINS && size, PJ_EINVAL);

    PJSUA_LOCK();

    w = &pjsua_var.win[wid];
    s = pjmedia_vid_port_get_stream(w->vp_rend? w->vp_rend: w->vp_cap);
    if (s == NULL) {
        PJSUA_UNLOCK();
        return PJ_EINVAL;
    }

    status = pjmedia_vid_dev_stream_set_cap(s,
                            PJMEDIA_VID_DEV_CAP_OUTPUT_RESIZE, size);

    PJSUA_UNLOCK();

    return status;
}

/*
 * Set output window.
 */
PJ_DEF(pj_status_t) pjsua_vid_win_set_win( pjsua_vid_win_id wid,
                                           const pjmedia_vid_dev_hwnd *win)
{
    pjsua_vid_win *w;
    pjmedia_vid_dev_stream *s;
    pj_status_t status;

    PJ_ASSERT_RETURN(wid >= 0 && wid < PJSUA_MAX_VID_WINS && win, PJ_EINVAL);

    PJSUA_LOCK();

    w = &pjsua_var.win[wid];
    s = pjmedia_vid_port_get_stream(w->vp_rend? w->vp_rend: w->vp_cap);
    if (s == NULL) {
        PJSUA_UNLOCK();
        return PJ_EINVAL;
    }

    status = pjmedia_vid_dev_stream_set_cap(s, 
                            PJMEDIA_VID_DEV_CAP_OUTPUT_WINDOW, win);

    PJSUA_UNLOCK();

    return status;
}

/*
 * Set video orientation.
 */
PJ_DEF(pj_status_t) pjsua_vid_win_rotate( pjsua_vid_win_id wid,
                                          int angle)
{
    pjsua_vid_win *w;
    pjmedia_vid_dev_stream *s;
    pjmedia_orient orient;
    pj_status_t status;

    PJ_ASSERT_RETURN(wid >= 0 && wid < PJSUA_MAX_VID_WINS, PJ_EINVAL);
    PJ_ASSERT_RETURN((angle % 90) == 0, PJ_EINVAL);

    /* Normalize angle, so it must be 0, 90, 180, or 270. */
    angle %= 360;
    if (angle < 0)
        angle += 360;

    /* Convert angle to pjmedia_orient */
    switch(angle) {
        case 0:
            /* No rotation */
            return PJ_SUCCESS;
        case 90:
            orient = PJMEDIA_ORIENT_ROTATE_90DEG;
            break;
        case 180:
            orient = PJMEDIA_ORIENT_ROTATE_180DEG;
            break;
        case 270:
            orient = PJMEDIA_ORIENT_ROTATE_270DEG;
            break;
        default:
            pj_assert(!"Angle must have been validated");
            return PJ_EBUG;
    }

    PJSUA_LOCK();

    w = &pjsua_var.win[wid];
    s = pjmedia_vid_port_get_stream(w->vp_rend? w->vp_rend: w->vp_cap);
    if (s == NULL) {
        PJSUA_UNLOCK();
        return PJ_EINVAL;
    }

    status = pjmedia_vid_dev_stream_set_cap(s,
                            PJMEDIA_VID_DEV_CAP_ORIENTATION, &orient);

    PJSUA_UNLOCK();

    return status;
}


/*
 * Set video window fullscreen.
 */
PJ_DEF(pj_status_t) pjsua_vid_win_set_fullscreen(
                                        pjsua_vid_win_id wid,
                                        pjmedia_vid_dev_fullscreen_flag mode)
{
    pjsua_vid_win *w;
    pjmedia_vid_dev_stream *s;
    pj_status_t status;

    PJ_ASSERT_RETURN(wid >= 0 && wid < PJSUA_MAX_VID_WINS, PJ_EINVAL);

    PJSUA_LOCK();

    w = &pjsua_var.win[wid];
    s = pjmedia_vid_port_get_stream(w->vp_rend? w->vp_rend: w->vp_cap);
    if (s == NULL) {
        PJSUA_UNLOCK();
        return PJ_EINVAL;
    }

    status = pjmedia_vid_dev_stream_set_cap(s,
                            PJMEDIA_VID_DEV_CAP_OUTPUT_FULLSCREEN, &mode);

    PJSUA_UNLOCK();

    return status;
}

static void call_get_vid_strm_info(pjsua_call *call,
                                   int *first_active,
                                   int *first_inactive,
                                   unsigned *active_cnt,
                                   unsigned *cnt)
{
    unsigned i, var_cnt = 0;

    if (first_active && ++var_cnt)
        *first_active = -1;
    if (first_inactive && ++var_cnt)
        *first_inactive = -1;
    if (active_cnt && ++var_cnt)
        *active_cnt = 0;
    if (cnt && ++var_cnt)
        *cnt = 0;

    for (i = 0; i < call->med_cnt && var_cnt; ++i) {
        if (call->media[i].type == PJMEDIA_TYPE_VIDEO) {
            if (call->media[i].dir != PJMEDIA_DIR_NONE)
            {
                if (first_active && *first_active == -1) {
                    *first_active = i;
                    --var_cnt;
                }
                if (active_cnt)
                    ++(*active_cnt);
            } else if (first_inactive && *first_inactive == -1) {
                *first_inactive = i;
                --var_cnt;
            }
            if (cnt)
                ++(*cnt);
        }
    }
}


/* Send SDP reoffer. */
static pj_status_t call_reoffer_sdp(pjsua_call_id call_id,
                                    pjmedia_sdp_session *sdp)
{
    pjsua_call *call;
    pjsip_tx_data *tdata;
    pjsip_dialog *dlg;
    pj_status_t status;

    status = acquire_call("call_reoffer_sdp()", call_id, &call, &dlg);
    if (status != PJ_SUCCESS)
        return status;

    if (call->inv->state != PJSIP_INV_STATE_CONFIRMED) {
        PJ_LOG(3,(THIS_FILE, "Can not re-INVITE call that is not confirmed"));
        pjsip_dlg_dec_lock(dlg);
        return PJSIP_ESESSIONSTATE;
    }

    /* Notify application */
    if (!call->hanging_up && pjsua_var.ua_cfg.cb.on_call_sdp_created) {
        (*pjsua_var.ua_cfg.cb.on_call_sdp_created)(call_id, sdp,
                                                   call->inv->pool_prov,
                                                   NULL);
    }

    /* Create re-INVITE with new offer */
    status = pjsip_inv_reinvite( call->inv, NULL, sdp, &tdata);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Unable to create re-INVITE", status);
        pjsip_dlg_dec_lock(dlg);
        return status;
    }

    /* Send the request */
    status = pjsip_inv_send_msg( call->inv, tdata);
    if (status != PJ_SUCCESS) {
        pjsua_perror(THIS_FILE, "Unable to send re-INVITE", status);
        pjsip_dlg_dec_lock(dlg);
        return status;
    }

    pjsip_dlg_dec_lock(dlg);

    return PJ_SUCCESS;
}

/* Add a new video stream into a call */
static pj_status_t call_add_video(pjsua_call *call,
                                  pjmedia_vid_dev_index cap_dev,
                                  pjmedia_dir dir)
{
    pj_pool_t *pool = call->inv->pool_prov;
    pjsua_acc_config *acc_cfg = &pjsua_var.acc[call->acc_id].cfg;
    pjsua_call_media *call_med;
    const pjmedia_sdp_session *current_sdp;
    pjmedia_sdp_session *sdp;
    pjmedia_sdp_media *sdp_m;
    pjmedia_transport_info tpinfo;
    unsigned options;
    pj_status_t status;

    /* Verify media slot availability */
    if (call->med_cnt == PJSUA_MAX_CALL_MEDIA)
        return PJ_ETOOMANY;

    if (pjsua_call_media_is_changing(call)) {
        PJ_LOG(1,(THIS_FILE, "Unable to add video" ERR_MEDIA_CHANGING));
        return PJ_EINVALIDOP;
    }

    /* Get active local SDP and clone it */
    status = pjmedia_sdp_neg_get_active_local(call->inv->neg, &current_sdp);
    if (status != PJ_SUCCESS)
        return status;

    sdp = pjmedia_sdp_session_clone(call->inv->pool_prov, current_sdp);

    /* Clean up & sync provisional media before using it */
    pjsua_media_prov_revert(call->index);

    /* Initialize call media */
    call_med = &call->media_prov[call->med_prov_cnt++];
    status = pjsua_call_media_init(call_med, PJMEDIA_TYPE_VIDEO,
                                   &acc_cfg->rtp_cfg, call->secure_level,
                                   NULL, PJ_FALSE, NULL);
    if (status != PJ_SUCCESS)
        goto on_error;

    /* Override default capture device setting */
    call_med->strm.v.cap_dev = cap_dev;

    /* Init transport media */
    options = (call_med->enable_rtcp_mux? PJMEDIA_TPMED_RTCP_MUX: 0);
    status = pjmedia_transport_media_create(call_med->tp, pool, options,
                                            NULL, call_med->idx);
    if (status != PJ_SUCCESS)
        goto on_error;

    pjsua_set_media_tp_state(call_med, PJSUA_MED_TP_INIT);

    /* Get transport address info */
    pjmedia_transport_info_init(&tpinfo);
    pjmedia_transport_get_info(call_med->tp, &tpinfo);

    /* Create SDP media line */
    status = pjmedia_endpt_create_video_sdp(pjsua_var.med_endpt, pool,
                                            &tpinfo.sock_info, 0, &sdp_m);
    if (status != PJ_SUCCESS)
        goto on_error;

    sdp->media[sdp->media_count++] = sdp_m;

    /* Update media direction, if it is not 'sendrecv' */
    if (dir != PJMEDIA_DIR_ENCODING_DECODING) {
        pjmedia_sdp_attr *a;

        /* Remove sendrecv direction attribute, if any */
        pjmedia_sdp_media_remove_all_attr(sdp_m, "sendrecv");

        if (dir == PJMEDIA_DIR_ENCODING)
            a = pjmedia_sdp_attr_create(pool, "sendonly", NULL);
        else if (dir == PJMEDIA_DIR_DECODING)
            a = pjmedia_sdp_attr_create(pool, "recvonly", NULL);
        else
            a = pjmedia_sdp_attr_create(pool, "inactive", NULL);

        pjmedia_sdp_media_add_attr(sdp_m, a);
    }

    /* Update SDP media line by media transport */
    status = pjmedia_transport_encode_sdp(call_med->tp, pool,
                                          sdp, NULL, call_med->idx);
    if (status != PJ_SUCCESS)
        goto on_error;

    status = call_reoffer_sdp(call->index, sdp);
    if (status != PJ_SUCCESS)
        goto on_error;

    call->opt.vid_cnt++;

    return PJ_SUCCESS;

on_error:
    if (call_med->tp) {
        pjsua_set_media_tp_state(call_med, PJSUA_MED_TP_NULL);
        pjmedia_transport_close(call_med->tp);
        call_med->tp = call_med->tp_orig = NULL;
    }
    call->med_prov_cnt = 0;

    return status;
}


/* Modify a video stream from a call, i.e: update direction,
 * remove/disable.
 */
static pj_status_t call_modify_video(pjsua_call *call,
                                     int med_idx,
                                     pjmedia_dir dir,
                                     pj_bool_t remove)
{
    pjsua_call_media *call_med;
    const pjmedia_sdp_session *current_sdp;
    pjmedia_sdp_session *sdp;
    pj_status_t status;

    if (pjsua_call_media_is_changing(call)) {
        PJ_LOG(1,(THIS_FILE, "Unable to modify video" ERR_MEDIA_CHANGING));
        return PJ_EINVALIDOP;
    }

    /* Verify and normalize media index */
    if (med_idx == -1) {
        int first_active;
        
        call_get_vid_strm_info(call, &first_active, NULL, NULL, NULL);
        if (first_active == -1)
            return PJ_ENOTFOUND;

        med_idx = first_active;
    }

    /* Clean up & sync provisional media before using it */
    pjsua_media_prov_revert(call->index);

    call_med = &call->media_prov[med_idx];

    /* Verify if the stream media type is video */
    if (call_med->type != PJMEDIA_TYPE_VIDEO)
        return PJ_EINVAL;

    /* Verify if the stream dir is not changed */
    if ((!remove && call_med->dir == dir) ||
        ( remove && (call_med->tp_st == PJSUA_MED_TP_DISABLED ||
                     call_med->tp == NULL)))
    {
        return PJ_SUCCESS;
    }

    /* Get active local SDP and clone it */
    status = pjmedia_sdp_neg_get_active_local(call->inv->neg, &current_sdp);
    if (status != PJ_SUCCESS)
        return status;

    sdp = pjmedia_sdp_session_clone(call->inv->pool_prov, current_sdp);

    pj_assert(med_idx < (int)sdp->media_count);

    if (!remove) {
        pjsua_acc_config *acc_cfg = &pjsua_var.acc[call->acc_id].cfg;
        pj_pool_t *pool = call->inv->pool_prov;
        pjmedia_sdp_media *sdp_m;

        /* Enabling video */
        if (call_med->dir == PJMEDIA_DIR_NONE) {
            unsigned i, vid_cnt = 0;

            /* Check if vid_cnt in call option needs to be increased */
            for (i = 0; i < call->med_cnt; ++i) {
                if (call->media[i].type == PJMEDIA_TYPE_VIDEO &&
                    call->media[i].dir != PJMEDIA_DIR_NONE)
                {
                    ++vid_cnt;
                }
            }
            if (call->opt.vid_cnt <= vid_cnt)
                call->opt.vid_cnt++;
        }

        status = pjsua_call_media_init(call_med, PJMEDIA_TYPE_VIDEO,
                                       &acc_cfg->rtp_cfg, call->secure_level,
                                       NULL, PJ_FALSE, NULL);
        if (status != PJ_SUCCESS)
            goto on_error;

        /* Init transport media */
        if (call_med->tp && call_med->tp_st == PJSUA_MED_TP_IDLE) {
            unsigned options = (call_med->enable_rtcp_mux?
                                PJMEDIA_TPMED_RTCP_MUX: 0);
            status = pjmedia_transport_media_create(call_med->tp, pool,
                                                    options, NULL,
                                                    call_med->idx);
            if (status != PJ_SUCCESS)
                goto on_error;
        }

        sdp_m = sdp->media[med_idx];

        /* Create new SDP media line if the stream is disabled */
        if (sdp->media[med_idx]->desc.port == 0) {
            pjmedia_transport_info tpinfo;

            /* Get transport address info */
            pjmedia_transport_info_init(&tpinfo);
            pjmedia_transport_get_info(call_med->tp, &tpinfo);

            status = pjmedia_endpt_create_video_sdp(pjsua_var.med_endpt, pool,
                                                    &tpinfo.sock_info, 0, &sdp_m);
            if (status != PJ_SUCCESS)
                goto on_error;
        }

        {
            pjmedia_sdp_attr *a;

            /* Remove any direction attributes */
            pjmedia_sdp_media_remove_all_attr(sdp_m, "sendrecv");
            pjmedia_sdp_media_remove_all_attr(sdp_m, "sendonly");
            pjmedia_sdp_media_remove_all_attr(sdp_m, "recvonly");
            pjmedia_sdp_media_remove_all_attr(sdp_m, "inactive");

            /* Update media direction */
            if (dir == PJMEDIA_DIR_ENCODING_DECODING)
                a = pjmedia_sdp_attr_create(pool, "sendrecv", NULL);
            else if (dir == PJMEDIA_DIR_ENCODING)
                a = pjmedia_sdp_attr_create(pool, "sendonly", NULL);
            else if (dir == PJMEDIA_DIR_DECODING)
                a = pjmedia_sdp_attr_create(pool, "recvonly", NULL);
            else
                a = pjmedia_sdp_attr_create(pool, "inactive", NULL);

            pjmedia_sdp_media_add_attr(sdp_m, a);
        }

        sdp->media[med_idx] = sdp_m;

        if (call_med->dir == PJMEDIA_DIR_NONE) {
            /* Update SDP media line by media transport */
            status = pjmedia_transport_encode_sdp(call_med->tp, pool,
                                                  sdp, NULL, call_med->idx);
            if (status != PJ_SUCCESS)
                goto on_error;
        }

on_error:
        if (status != PJ_SUCCESS) {
            /* Revert back provisional media. */
            pjsua_media_prov_revert(call->index);

            return status;
        }
    
    } else {

        pj_pool_t *pool = call->inv->pool_prov;

        /* Mark media transport to disabled */
        // Don't close this here, as SDP negotiation has not been
        // done and stream may be still active.
        pjsua_set_media_tp_state(call_med, PJSUA_MED_TP_DISABLED);

        /* Deactivate the stream */
        pjmedia_sdp_media_deactivate(pool, sdp->media[med_idx]);

        call->opt.vid_cnt--;
    }

    status = call_reoffer_sdp(call->index, sdp);
    if (status != PJ_SUCCESS)
        return status;

    return PJ_SUCCESS;
}


/* Change capture device of a video stream in a call */
static pj_status_t call_change_cap_dev(pjsua_call *call,
                                       int med_idx,
                                       pjmedia_vid_dev_index cap_dev)
{
    pjsua_call_media *call_med;
    pjmedia_vid_dev_stream *old_dev;
    pjmedia_vid_dev_switch_param switch_prm;
    pjmedia_vid_dev_info info;
    pjsua_vid_win *w, *new_w = NULL;
    pjsua_vid_win_id wid, new_wid;
    pjmedia_port *media_port;
    pj_status_t status;

    /* Verify and normalize media index */
    if (med_idx == -1) {
        int first_active;
        
        call_get_vid_strm_info(call, &first_active, NULL, NULL, NULL);
        if (first_active == -1)
            return PJ_ENOTFOUND;

        med_idx = first_active;
    }

    call_med = &call->media[med_idx];

    /* Verify if the stream media type is video */
    if (call_med->type != PJMEDIA_TYPE_VIDEO)
        return PJ_EINVAL;

    /* Verify the capture device */
    status = pjmedia_vid_dev_get_info(cap_dev, &info);
    if (status != PJ_SUCCESS || (info.dir & PJMEDIA_DIR_CAPTURE) == 0)
        return PJ_EINVAL;

    /* The specified capture device is being used already */
    if (call_med->strm.v.cap_dev == cap_dev)
        return PJ_SUCCESS;

    /* == Apply the new capture device == */
    PJSUA_LOCK();

    /* If media does not have active preview, simply set capture device ID */
    if (call_med->strm.v.cap_win_id == PJSUA_INVALID_ID) {
        call_med->strm.v.cap_dev = cap_dev;

        /* That's it */
        goto on_sync_and_return;
    }

    wid = call_med->strm.v.cap_win_id;
    w = &pjsua_var.win[wid];
    pj_assert(w->type == PJSUA_WND_TYPE_PREVIEW && w->vp_cap);

    /* If the old device supports fast switching, then that's excellent! */
    old_dev = pjmedia_vid_port_get_stream(w->vp_cap);
    pjmedia_vid_dev_switch_param_default(&switch_prm);
    switch_prm.target_id = cap_dev;
    status = pjmedia_vid_dev_stream_set_cap(old_dev,
                                            PJMEDIA_VID_DEV_CAP_SWITCH,
                                            &switch_prm);
    if (status == PJ_SUCCESS) {
        w->preview_cap_id = cap_dev;
        call_med->strm.v.cap_dev = cap_dev;

        /* Yay, change capturer done! Now return */
        goto on_sync_and_return;
    }

    /* Oh no, it doesn't support fast switching. Do normal change then,
     * i.e: remove the old and create a new capture.
     */
    status = pjmedia_vid_stream_get_port(call_med->strm.v.stream,
                                         PJMEDIA_DIR_ENCODING, &media_port);
    if (status != PJ_SUCCESS) {
        PJSUA_UNLOCK();
        return status;
    }

    media_event_unsubscribe(NULL, &call_media_on_event, call_med, w->vp_cap);
    
    /* Disconnect the old capture device to stream encoding port */
    status = pjsua_vid_conf_disconnect(w->cap_slot,
                                       call_med->strm.v.strm_enc_slot);
    if (status != PJ_SUCCESS) {
        PJSUA_UNLOCK();
        return status;
    }


    /* = Attach stream port to the new capture device = */

    /* Note: calling pjsua_vid_preview_get_win() even though
     * create_vid_win() will automatically create the window
     * if it doesn't exist, because create_vid_win() will modify
     * existing window SHOW/HIDE value.
     */
    new_wid = vid_preview_get_win(cap_dev, PJ_FALSE);
    if (new_wid == PJSUA_INVALID_ID) {
        pjsua_acc *acc = &pjsua_var.acc[call_med->call->acc_id];

        /* Create preview video window */
        status = create_vid_win(PJSUA_WND_TYPE_PREVIEW,
                                &media_port->info.fmt,
                                call_med->strm.v.rdr_dev,
                                cap_dev,
                                PJSUA_HIDE_WINDOW,
                                acc->cfg.vid_wnd_flags,
                                NULL,
                                &new_wid);
        if (status != PJ_SUCCESS)
            goto on_error;
    }

    inc_vid_win(new_wid);
    new_w = &pjsua_var.win[new_wid];

    if (new_w->vp_rend) {
        /* Start renderer */
        status = pjmedia_vid_port_start(new_w->vp_rend);
        if (status != PJ_SUCCESS)
            goto on_error;
    }

#if ENABLE_EVENT
    pjmedia_event_subscribe(NULL, &call_media_on_event,
                            call_med, new_w->vp_cap);
#endif

    /* Start capturer */
    if (!pjmedia_vid_port_is_running(new_w->vp_cap)) {
        status = pjmedia_vid_port_start(new_w->vp_cap);
        if (status != PJ_SUCCESS)
            goto on_error;
    }

    /* Connect capturer to stream encoding port (via conf) */
    status = pjsua_vid_conf_connect(new_w->cap_slot,
                                    call_med->strm.v.strm_enc_slot,
                                    NULL);
    if (status != PJ_SUCCESS)
        goto on_error;

    /* Finally */
    call_med->strm.v.cap_dev = cap_dev;
    call_med->strm.v.cap_win_id = new_wid;
    dec_vid_win(wid);

on_sync_and_return:

    /* Sync provisional media from call media */
    pj_memcpy(&call->media_prov[med_idx], call_med, sizeof(call->media[0]));

    PJSUA_UNLOCK();

    return PJ_SUCCESS;

on_error:
    PJ_PERROR(4,(THIS_FILE, status,
                 "Call %d: error changing capture device to %d",
                 call->index, cap_dev));

    if (new_w) {
        /* Unsubscribe, just in case */
        media_event_unsubscribe(NULL, &call_media_on_event, call_med,
                                new_w->vp_cap);

        /* Release the new capturer */
        dec_vid_win(new_wid);
    }

    /* Revert back to the old capturer */
    status = pjsua_vid_conf_connect(w->cap_slot,
                                    call_med->strm.v.strm_enc_slot, NULL);
    if (status != PJ_SUCCESS) {
        PJSUA_UNLOCK();
        return status;
    }

#if ENABLE_EVENT
    /* Resubscribe */
    pjmedia_event_subscribe(NULL, &call_media_on_event,
                            call_med, w->vp_cap);
#endif

    PJSUA_UNLOCK();

    return status;
}


/* Start/stop transmitting video stream in a call */
static pj_status_t call_set_tx_video(pjsua_call *call,
                                     int med_idx,
                                     pj_bool_t enable)
{
    pjsua_call_media *call_med;
    pj_status_t status;

    /* Verify and normalize media index */
    if (med_idx == -1) {
        int first_active;
        
        call_get_vid_strm_info(call, &first_active, NULL, NULL, NULL);
        if (first_active == -1)
            return PJ_ENOTFOUND;

        med_idx = first_active;
    }

    call_med = &call->media[med_idx];

    /* Verify if the stream is transmitting video */
    if (call_med->type != PJMEDIA_TYPE_VIDEO || 
        (enable && (call_med->dir & PJMEDIA_DIR_ENCODING) == 0))
    {
        return PJ_EINVAL;
    }

    if (enable) {
        if (call_med->strm.v.cap_win_id == PJSUA_INVALID_ID) {
            /* Setup the video capture first */
            status = setup_vid_capture(call_med);
            if (status != PJ_SUCCESS)
                return status;
        }
        
        /* Resume stream in encoding direction */
        status = pjmedia_vid_stream_resume(call_med->strm.v.stream,
                                           PJMEDIA_DIR_ENCODING);
    } else {
        pjsua_vid_win_id wid;
        pjsua_vid_win *w;

        /* Pause stream in encoding direction */
        status = pjmedia_vid_stream_pause( call_med->strm.v.stream,
                                           PJMEDIA_DIR_ENCODING);
        
        PJSUA_LOCK();
        
        wid = vid_preview_get_win(call_med->strm.v.cap_dev, PJ_FALSE);
        if (wid != PJSUA_INVALID_ID) {
            w = &pjsua_var.win[wid];

            /* Unsubscribe event */
            media_event_unsubscribe(NULL, &call_media_on_event, call_med,
                                    w->vp_cap);

            /* Disconnect from video conference */
            pjsua_vid_conf_disconnect(w->cap_slot,
                                      call_med->strm.v.strm_enc_slot);

            /* Decrement ref count of the video window */
            dec_vid_win(call_med->strm.v.cap_win_id);
            call_med->strm.v.cap_win_id = PJSUA_INVALID_ID;
        }
        
        PJSUA_UNLOCK();
    }

    /* Sync provisional media from call media */
    pj_memcpy(&call->media_prov[med_idx], call_med, sizeof(call->media[0]));

    return status;
}


static pj_status_t call_send_vid_keyframe(pjsua_call *call,
                                          int med_idx)
{
    pjsua_call_media *call_med;

    /* Verify and normalize media index */
    if (med_idx == -1) {
        int first_active;
        
        call_get_vid_strm_info(call, &first_active, NULL, NULL, NULL);
        if (first_active == -1)
            return PJ_ENOTFOUND;

        med_idx = first_active;
    }

    call_med = &call->media[med_idx];

    /* Verify media type and stream instance. */
    if (call_med->type != PJMEDIA_TYPE_VIDEO || !call_med->strm.v.stream)
        return PJ_EINVAL;

    return pjmedia_vid_stream_send_keyframe(call_med->strm.v.stream);
}


/*
 * Start, stop, and/or manipulate video transmission for the specified call.
 */
PJ_DEF(pj_status_t) pjsua_call_set_vid_strm (
                                pjsua_call_id call_id,
                                pjsua_call_vid_strm_op op,
                                const pjsua_call_vid_strm_op_param *param)
{
    pjsua_call *call;
    pjsip_dialog *dlg = NULL;
    pjsua_call_vid_strm_op_param param_;
    pj_status_t status;

    PJ_ASSERT_RETURN(call_id>=0 && call_id<(int)pjsua_var.ua_cfg.max_calls,
                     PJ_EINVAL);
    PJ_ASSERT_RETURN(op != PJSUA_CALL_VID_STRM_NO_OP, PJ_EINVAL);

    PJ_LOG(4,(THIS_FILE, "Call %d: set video stream, op=%d",
              call_id, op));
    pj_log_push_indent();

    status = acquire_call("pjsua_call_set_vid_strm()", call_id, &call, &dlg);
    if (status != PJ_SUCCESS)
        goto on_return;

    if (param) {
        param_ = *param;
    } else {
        pjsua_call_vid_strm_op_param_default(&param_);
    }

    /* If set to PJMEDIA_VID_DEFAULT_CAPTURE_DEV, replace it with
     * account default video capture device.
     */
    if (param_.cap_dev == PJMEDIA_VID_DEFAULT_CAPTURE_DEV) {
        pjsua_acc_config *acc_cfg = &pjsua_var.acc[call->acc_id].cfg;
        param_.cap_dev = acc_cfg->vid_cap_dev;
        
        /* If the account default video capture device is
         * PJMEDIA_VID_DEFAULT_CAPTURE_DEV, replace it with
         * global default video capture device.
         */
        if (param_.cap_dev == PJMEDIA_VID_DEFAULT_CAPTURE_DEV) {
            pjmedia_vid_dev_info info;
            pjmedia_vid_dev_get_info(param_.cap_dev, &info);
            pj_assert(info.dir == PJMEDIA_DIR_CAPTURE);
            param_.cap_dev = info.id;
        }
    }

    switch (op) {
    case PJSUA_CALL_VID_STRM_ADD:
        status = call_add_video(call, param_.cap_dev, param_.dir);
        break;
    case PJSUA_CALL_VID_STRM_REMOVE:
        status = call_modify_video(call, param_.med_idx, PJMEDIA_DIR_NONE,
                                   PJ_TRUE);
        break;
    case PJSUA_CALL_VID_STRM_CHANGE_DIR:
        status = call_modify_video(call, param_.med_idx, param_.dir, PJ_FALSE);
        break;
    case PJSUA_CALL_VID_STRM_CHANGE_CAP_DEV:
        status = call_change_cap_dev(call, param_.med_idx, param_.cap_dev);
        break;
    case PJSUA_CALL_VID_STRM_START_TRANSMIT:
        status = call_set_tx_video(call, param_.med_idx, PJ_TRUE);
        break;
    case PJSUA_CALL_VID_STRM_STOP_TRANSMIT:
        status = call_set_tx_video(call, param_.med_idx, PJ_FALSE);
        break;
    case PJSUA_CALL_VID_STRM_SEND_KEYFRAME:
        status = call_send_vid_keyframe(call, param_.med_idx);
        break;
    default:
        status = PJ_EINVALIDOP;
        break;
    }

on_return:
    if (dlg) pjsip_dlg_dec_lock(dlg);
    pj_log_pop_indent();
    return status;
}


/*
 * Get the media stream index of the default video stream in the call.
 */
PJ_DEF(int) pjsua_call_get_vid_stream_idx(pjsua_call_id call_id)
{
    pjsua_call *call;
    int first_active, first_inactive;

    PJ_ASSERT_RETURN(call_id>=0 && call_id<(int)pjsua_var.ua_cfg.max_calls,
                     PJ_EINVAL);

    PJSUA_LOCK();
    call = &pjsua_var.calls[call_id];
    call_get_vid_strm_info(call, &first_active, &first_inactive, NULL, NULL);
    PJSUA_UNLOCK();

    if (first_active == -1)
        return first_inactive;

    return first_active;
}


/*
 * Determine if video stream for the specified call is currently running
 * for the specified direction.
 */
PJ_DEF(pj_bool_t) pjsua_call_vid_stream_is_running( pjsua_call_id call_id,
                                                    int med_idx,
                                                    pjmedia_dir dir)
{
    pjsua_call *call;
    pjsua_call_media *call_med;

    PJ_ASSERT_RETURN(call_id>=0 && call_id<(int)pjsua_var.ua_cfg.max_calls,
                     PJ_EINVAL);

    /* Verify and normalize media index */
    if (med_idx == -1) {
        med_idx = pjsua_call_get_vid_stream_idx(call_id);
    }

    call = &pjsua_var.calls[call_id];
    PJ_ASSERT_RETURN(med_idx >= 0 && med_idx < (int)call->med_cnt, PJ_EINVAL);

    call_med = &call->media[med_idx];

    /* Verify if the stream is transmitting video */
    if (call_med->type != PJMEDIA_TYPE_VIDEO || (call_med->dir & dir) == 0 ||
        !call_med->strm.v.stream)
    {
        return PJ_FALSE;
    }

    return pjmedia_vid_stream_is_running(call_med->strm.v.stream, dir);
}


/*****************************************************************************
 * Video conference
 */

/*
 * Get current number of active ports in the bridge.
 */
PJ_DEF(unsigned) pjsua_vid_conf_get_active_ports(void)
{
    return pjmedia_vid_conf_get_port_count(pjsua_var.vid_conf);
}


/*
 * Enumerate all video conference ports.
 */
PJ_DEF(pj_status_t) pjsua_vid_conf_enum_ports( pjsua_conf_port_id id[],
                                               unsigned *count)
{
    return pjmedia_vid_conf_enum_ports(pjsua_var.vid_conf,
                                       (unsigned*)id, count);
}


/*
 * Get information about the specified video conference port
 */
PJ_DEF(pj_status_t) pjsua_vid_conf_get_port_info(
                                            pjsua_conf_port_id port_id,
                                            pjsua_vid_conf_port_info *info)
{
    pjmedia_vid_conf_port_info cinfo;
    unsigned i;
    pj_status_t status;

    PJ_ASSERT_RETURN(port_id >= 0, PJ_EINVAL);

    status = pjmedia_vid_conf_get_port_info(pjsua_var.vid_conf,
                                            (unsigned)port_id, &cinfo);
    if (status != PJ_SUCCESS)
        return status;

    pj_bzero(info, sizeof(*info));
    info->slot_id = port_id;
    info->name = cinfo.name;
    pjmedia_format_copy(&info->format, &cinfo.format);

    /* Build array of listeners */
    info->listener_cnt = cinfo.listener_cnt;
    for (i=0; i<cinfo.listener_cnt; ++i) {
        info->listeners[i] = cinfo.listener_slots[i];
    }

    /* Build array of transmitters */
    info->transmitter_cnt = cinfo.transmitter_cnt;
    for (i=0; i<cinfo.transmitter_cnt; ++i) {
        info->transmitters[i] = cinfo.transmitter_slots[i];
    }

    return PJ_SUCCESS;

}


/*
 * Add arbitrary video media port to PJSUA's video conference bridge.
 */
PJ_DEF(pj_status_t) pjsua_vid_conf_add_port( pj_pool_t *pool,
                                             pjmedia_port *port,
                                             const void *param,
                                             pjsua_conf_port_id *p_id)
{
    pj_status_t status;

    PJ_UNUSED_ARG(param);

    status = pjmedia_vid_conf_add_port(pjsua_var.vid_conf, pool,
                                       port, NULL, NULL, (unsigned*)p_id);
    if (status != PJ_SUCCESS) {
        if (p_id)
            *p_id = PJSUA_INVALID_ID;
    }

    return status;
}


/*
 * Remove arbitrary slot from the video conference bridge.
 */
PJ_DEF(pj_status_t) pjsua_vid_conf_remove_port(pjsua_conf_port_id id)
{
    PJ_ASSERT_RETURN(id >= 0, PJ_EINVAL);

    return pjmedia_vid_conf_remove_port(pjsua_var.vid_conf, (unsigned)id);
}


/*
 * Establish unidirectional video flow from souce to sink.
 */
PJ_DEF(pj_status_t) pjsua_vid_conf_connect( pjsua_conf_port_id source,
                                            pjsua_conf_port_id sink,
                                            const void *param)
{
    PJ_UNUSED_ARG(param);

    PJ_ASSERT_RETURN(source >= 0 && sink >= 0, PJ_EINVAL);

    return pjmedia_vid_conf_connect_port(pjsua_var.vid_conf, source, sink,
                                         NULL);
}


/*
 * Disconnect video flow from the source to destination port.
 */
PJ_DEF(pj_status_t) pjsua_vid_conf_disconnect(pjsua_conf_port_id source,
                                              pjsua_conf_port_id sink)
{
    PJ_ASSERT_RETURN(source >= 0 && sink >= 0, PJ_EINVAL);

    return pjmedia_vid_conf_disconnect_port(pjsua_var.vid_conf, source, sink);
}


/*
 * Update or refresh port states from video port info.
 */
PJ_DEF(pj_status_t) pjsua_vid_conf_update_port(pjsua_conf_port_id id)
{
    return pjmedia_vid_conf_update_port(pjsua_var.vid_conf, id);
}


/*
 * Get the video window associated with the call.
 */
PJ_DEF(pjsua_vid_win_id) pjsua_call_get_vid_win(pjsua_call_id call_id)
{
    pjsua_call *call;
    pjsua_vid_win_id wid = PJSUA_INVALID_ID;
    unsigned i;

    PJ_ASSERT_RETURN(call_id>=0 && call_id<(int)pjsua_var.ua_cfg.max_calls,
                     PJ_EINVAL);

    /* Use PJSUA_LOCK() instead of acquire_call():
     *  https://github.com/pjsip/pjproject/issues/1371
     */
    PJSUA_LOCK();

    if (!pjsua_call_is_active(call_id))
        goto on_return;

    call = &pjsua_var.calls[call_id];
    for (i = 0; i < call->med_cnt; ++i) {
        if (call->media[i].type == PJMEDIA_TYPE_VIDEO &&
            (call->media[i].dir & PJMEDIA_DIR_DECODING))
        {
            wid = call->media[i].strm.v.rdr_win_id;
            break;
        }
    }

on_return:
    PJSUA_UNLOCK();

    return wid;
}


/*
 * Get the video conference port identification associated with the call.
 */
PJ_DEF(pjsua_conf_port_id) pjsua_call_get_vid_conf_port(
                                                    pjsua_call_id call_id,
                                                    pjmedia_dir dir)
{
    pjsua_call *call;
    pjsua_conf_port_id port_id = PJSUA_INVALID_ID;
    unsigned i;

    PJ_ASSERT_RETURN(call_id>=0 && call_id<(int)pjsua_var.ua_cfg.max_calls,
                     PJ_EINVAL);
    PJ_ASSERT_RETURN(dir==PJMEDIA_DIR_ENCODING || dir==PJMEDIA_DIR_DECODING,
                     PJ_EINVAL);

    /* Use PJSUA_LOCK() instead of acquire_call():
     *  https://github.com/pjsip/pjproject/issues/1371
     */
    PJSUA_LOCK();

    if (!pjsua_call_is_active(call_id))
        goto on_return;

    call = &pjsua_var.calls[call_id];
    for (i = 0; i < call->med_cnt; ++i) {
        if (call->media[i].type == PJMEDIA_TYPE_VIDEO &&
            (call->media[i].dir & dir))
        {
            port_id = (dir==PJMEDIA_DIR_ENCODING)?
                                    call->media[i].strm.v.strm_enc_slot :
                                    call->media[i].strm.v.strm_dec_slot;
            break;
        }
    }

on_return:
    PJSUA_UNLOCK();

    return port_id;
}


#endif /* PJSUA_HAS_VIDEO */

#endif /* PJSUA_MEDIA_HAS_PJMEDIA */
