namespace Vinno.vCloud.FIS.CrossPlatform.Windows.LiveVideo
{
    public class VideoHelper
    {
        /// <summary>
        /// 计算码率
        /// </summary>
        /// <param name="frameRate">帧率</param>
        /// <param name="width">宽度</param>
        /// <param name="height">高度</param>
        /// <returns></returns>
        public static int CalBitRate(int frameRate, int width, int height)
        {
            int kbit_rate = 2000;

            int area = width * height;

            if (area <= (320 * 300))
            {
                kbit_rate = 280;
            }
            else if (area <= (360 * 320))
            {
                kbit_rate = 360;
            }
            else if (area <= (640 * 480))
            {
                kbit_rate = 580;
            }
            else if (area <= (800 * 600))
            {
                kbit_rate = 620;
            }
            else if (area <= (900 * 700))
            {
                kbit_rate = 820;
            }
            else if (area <= (1280 * 720))
            {
                kbit_rate = 1600;
            }
            else if (area <= (1366 * 768))
            {
                kbit_rate = 2000;
            }
            else if (area <= (1600 * 900))
            {
                kbit_rate = 2300;
            }
            else if (area <= (1600 * 1050))
            {
                kbit_rate = 2500;
            }
            else
            {
                kbit_rate = 2800;
            }

            kbit_rate = kbit_rate * frameRate / 20;

            if (kbit_rate < 80)
                kbit_rate = 80;

            return kbit_rate;
        }

        /// <summary>
        /// 计算最大码率
        /// </summary>
        /// <param name="frameRate">帧率</param>
        /// <param name="width">宽度</param>
        /// <param name="height">高度</param>
        /// <param name="isVarBitrate">是否使用平均码率</param>
        /// <returns></returns>
        public static int CalMaxKBitRate(int frameRate, int width, int height, bool isVarBitrate)
        {
            int max_kbit_rate = 2000;

            int area = width * height;

            if (area <= (320 * 300))
            {
                max_kbit_rate = isVarBitrate ? 320 : 600;
            }
            else if (area <= (360 * 320))
            {
                max_kbit_rate = isVarBitrate ? 400 : 800;
            }
            else if (area <= (640 * 360))
            {
                max_kbit_rate = isVarBitrate ? 600 : 1000;
            }
            else if (area <= (640 * 480))
            {
                max_kbit_rate = isVarBitrate ? 680 : 1300;
            }
            else if (area <= (800 * 600))
            {
                max_kbit_rate = isVarBitrate ? 700 : 1500;
            }
            else if (area <= (900 * 700))
            {
                max_kbit_rate = isVarBitrate ? 920 : 2200;
            }
            else if (area <= (1280 * 720))
            {
                max_kbit_rate = isVarBitrate ? 1600 : 3000;
            }
            else if (area <= (1366 * 768))
            {
                max_kbit_rate = isVarBitrate ? 1700 : 3300;
            }
            else if (area <= (1600 * 900))
            {
                max_kbit_rate = isVarBitrate ? 2400 : 3400;
            }
            else if (area <= (1600 * 1050))
            {
                max_kbit_rate = isVarBitrate ? 2600 : 3600;
            }
            else if (area <= (1920 * 1080))
            {
                max_kbit_rate = isVarBitrate ? 2900 : 3800;
            }
            else
            {
                max_kbit_rate = isVarBitrate ? 3500 : 5500;
            }

            max_kbit_rate = max_kbit_rate * frameRate / 25;

            if (area <= (320 * 240))
            {
                if (max_kbit_rate < 150)
                    max_kbit_rate = 150;
            }
            else if (area <= (640 * 480))
            {
                if (max_kbit_rate < 300)
                    max_kbit_rate = 300;
            }
            else if (area <= (1280 * 720))
            {
                if (max_kbit_rate < 600)
                    max_kbit_rate = 600;
            }
            else if (area <= (1920 * 1080))
            {
                if (max_kbit_rate < 960)
                    max_kbit_rate = 960;
            }
            else
            {
                if (max_kbit_rate < 1500)
                    max_kbit_rate = 1500;
            }

            return max_kbit_rate;
        }

        /// <summary>
        /// 计算视频质量
        /// </summary>
        /// <param name="width">宽度</param>
        /// <param name="height">高度</param>
        /// <param name="ish264">是否使用h264</param>
        /// <returns></returns>
        public static int CalVideoQuality(int width, int height, bool ish264)
        {
            int area = width * height;

            int quality = ish264 ? 23 : 28;

            if (area <= (320 * 240))
            {
                quality = ish264 ? 23 : 27;
            }
            else if (area <= (640 * 360))
            {
                quality = ish264 ? 25 : 28;
            }
            else if (area <= (640 * 480))
            {
                quality = ish264 ? 25 : 28;
            }
            else if (area <= (960 * 600))
            {
                quality = ish264 ? 26 : 28;
            }
            else if (area <= (1280 * 720))
            {
                quality = ish264 ? 27 : 29;
            }
            else if (area <= (1600 * 900))
            {
                quality = ish264 ? 28 : 30;
            }
            else if (area <= (1920 * 1080))
            {
                quality = ish264 ? 29 : 31;
            }
            else
            {
                quality = ish264 ? 30 : 32;
            }

            return quality;
        }

        /// <summary>
        /// 计算视频编码速度
        /// </summary>
        /// <param name="width">宽度</param>
        /// <param name="height">高度</param>
        /// <param name="ish264">是否使用h264</param>
        /// <returns></returns>
        public static int CalVideoEncoderSpeed(int width, int height, bool ish264)
        {
            if (ish264)
                return 3;

            int area = width * height;

            if (area <= (960 * 600))
            {
                return 3;
            }
            else if (area <= (1280 * 720))
            {
                return 2;
            }
            else
            {
                return 1;
            }
        }
    }
}