订阅与收流

int rtc_subscribe_audio(void* handle, const char* uid, const char* track_id);

int rtc_subscribe_video(void* handle, const char* uid, const char* track_id);

int rtc_unsubscribe(void* handle, const char* uid, const char* track_id);

static void* g_rtc = NULL;

// 在轨道事件里挑要订阅的轨道
static void on_track_event(void* ctx, const char* uid,
                           rtc_track_info_t* track, int event_type) {
    if (event_type != 0) return;   // 只处理"新增"

    // 只订阅目标用户的视频
    if (strcmp(uid, "target_user_id") == 0 && track->kind == 1) {
        rtc_subscribe_video(g_rtc, uid, track->track_id);
    }
    // 所有人的音频都订上
    if (track->kind == 0) {
        rtc_subscribe_audio(g_rtc, uid, track->track_id);
    }
}

int main() {
    g_rtc = rtc_create();
    rtc_set_track_event_callback(g_rtc, on_track_event, NULL);
    rtc_set_track_sample_callback(g_rtc, on_track_sample, NULL);
    // 不开自动订阅
    rtc_join_channel_sync(g_rtc, token, 10000);
    // ...
}

int rtc_request_key_frame(void* handle, const char* uid, const char* track_id);