对最近的RTP和H264学习进行总结整理-04.20_.NET_编程开发_程序员俱乐部

　　虽然还是没有搞出来，但总感觉快了哈哈（哪来的自信）

　　1、RTP协议接受数据

#region 1-RTP协议变量声明
        RTPSession session;
        RTPReceiver receiver;
        RTPParticipant participant;
        private Dictionary<uint, List<RTPPacket>> Clients;
#endregion  


#region 对RTP进行初始化,并接收数据,调用之后就可以接收数据了
            session = new RTPSession();
            receiver = new RTPReceiver();
            IPEndPoint rtpEp = new IPEndPoint(IPAddress.Parse("192.168.1.109"), 5000);
            participant = new RTPParticipant(rtpEp);
            receiver.AddParticipant(participant);
            session.NewRTPPacket = new RTPSession.NewRTPPacket_Callback(NewRTPPacket);
            session.AddReceiver(receiver);
            Clients = new Dictionary<uint, List<RTPPacket>>();
#endregion

 

　　其中NewRTPPackt是

public delegate bool NewRTPPacket_Callback(
    RTPPacket packet
)

类型的委托。packet为接收到的RTP包，我们就对这些包进行处理得到想要的帧，然后再把帧进行解码，得到想要的图像（我是这样理解的）

　　2、H.264进行解码

　　我从网络上搜索到了一个海思的DLL,可以对H.264进行解码

　　

#region 解码器相关变量声明
        /// <summary>
        /// 数据的句柄
        /// </summary>
        IntPtr pData;
        /// <summary>
        /// 这是解码器属性信息
        /// </summary>
        public H264Dec.hiH264_DEC_ATTR_S decAttr;
        /// <summary>
        /// 这是解码器输出图像信息
        /// </summary>
        public H264Dec.hiH264_DEC_FRAME_S _decodeFrame = new H264Dec.hiH264_DEC_FRAME_S();
        /// <summary>
        /// 解码器句柄
        /// </summary>
        public IntPtr _decHandle; 
#endregion


 #region 解码器相关初始化，一般在窗口load中进行初始化
            decAttr = new H264Dec.hiH264_DEC_ATTR_S();
            decAttr.uPictureFormat = 0;
            decAttr.uStreamInType = 0;
            decAttr.uPicWidthInMB = 480 >> 4;
            decAttr.uPicHeightInMB = 640 >> 4;
            decAttr.uBufNum = 8;
            decAttr.uWorkMode = 16;
            //创建、初始化解码器句柄
            _decHandle = H264Dec.Hi264DecCreate(ref decAttr);
            //_decodeFrame = new H264Dec.hiH264_DEC_FRAME_S();
#endregion


//这一写代码就是h264解码的代码，其中未声明的函数和变量会在下面进行声明给出，主要是讲YUV转为RGB，在保存为Bitmap文件
if (H264Dec.Hi264DecAU(_decHandle, pData, (uint)newData.Length, 0, ref _decodeFrame, 0) == 0)
                {
                    if (_decodeFrame.bError == 0)
                    {
                        //策画 y u v 的长度
                        var yLength = _decodeFrame.uHeight * _decodeFrame.uYStride;
                        var uLength = _decodeFrame.uHeight * _decodeFrame.uUVStride / 2;
                        var vLength = uLength;
                        var yBytes = new byte[yLength];
                        var uBytes = new byte[uLength];
                        var vBytes = new byte[vLength];
                        var decodedBytes = new byte[yLength + uLength + vLength];

                        //_decodeFrame 是解码后的数据对象,里面包含 YUV 数据、宽度、高度等信息

                        Marshal.Copy(_decodeFrame.pY, yBytes, 0, (int)yLength);
                        Marshal.Copy(_decodeFrame.pU, uBytes, 0, (int)uLength);
                        Marshal.Copy(_decodeFrame.pV, vBytes, 0, (int)vLength);

                        //将从 _decodeFrame 中取出的 YUV 数据放入 decodedBytes 中
                        Array.Copy(yBytes, decodedBytes, yLength);
                        Array.Copy(uBytes, 0, decodedBytes, yLength, uLength);
                        Array.Copy(vBytes, 0, decodedBytes, yLength + uLength, vLength);

                        ConvertYUV2RGB(yuv, rgb, width, height);
                        ConvertYUV2RGB(decodedBytes, rgb, width, height);
                        // 写 BMP 文件。
                        WriteBMP(rgb, width, height, string.Format("E:\\test\\yuv2bmp_{0}.bmp", index++));
                    }
                }

　　其中pData为需要的一帧数据，因为pData为Intptr类型，而一帧数据是byte[]类型，所以我从网上查了查怎么转换，下面是代码，newData是byte【】，pData是intptr类型。

 GCHandle hObject = GCHandle.Alloc(newData, GCHandleType.Pinned);
 pData = hObject.AddrOfPinnedObject();

　　H264解码类

class="code_img_closed" src="/Upload/Images/2015042110/0015B68B3C38AA5B.gif" alt="" />logs_code_hide('31ff1815-52c8-4eb6-98f9-e63c96beb5a8',event)" src="/Upload/Images/2015042110/2B1B950FA3DF188F.gif" alt="" />

public class H264Dec
    {
        public const int HI_SUCCESS = 0;

        public const int HI_FAILURE = -1;

        public const int HI_LITTLE_ENDIAN = 1234;

        public const int HI_BIG_ENDIAN = 4321;

        public const int HI_DECODER_SLEEP_TIME = 60000;

        public const int HI_H264DEC_OK = 0;

        public const int HI_H264DEC_NEED_MORE_BITS = -1;

        public const int HI_H264DEC_NO_PICTURE = -2;

        public const int HI_H264DEC_ERR_HANDLE = -3;



        [DllImport("hi_h264dec_w.dll", EntryPoint = "Hi264DecImageEnhance", CallingConvention = CallingConvention.Cdecl)]
        public static extern int Hi264DecImageEnhance(IntPtr hDec, ref hiH264_DEC_FRAME_S pDecFrame, uint uEnhanceCoeff);

        [DllImport("hi_h264dec_w.dll", EntryPoint = "Hi264DecCreate", CallingConvention = CallingConvention.Cdecl)]
        public static extern IntPtr Hi264DecCreate(ref hiH264_DEC_ATTR_S pDecAttr);

        [DllImport("hi_h264dec_w.dll", EntryPoint = "Hi264DecDestroy", CallingConvention = CallingConvention.Cdecl)]
        public static extern void Hi264DecDestroy(IntPtr hDec);


        [DllImport("hi_h264dec_w.dll", EntryPoint = "Hi264DecGetInfo", CallingConvention = CallingConvention.Cdecl)]
        public static extern int Hi264DecGetInfo(ref hiH264_LIBINFO_S pLibInfo);

        /// <summary>
        /// 对输入的一段码流进行解码并按帧输出图像
        /// </summary>
        /// <param name="hDec">解码器句柄</param>
        /// <param name="pStream">码流起始地址</param>
        /// <param name="iStreamLen">码流长度</param>
        /// <param name="ullPTS">时间戳信息</param>
        /// <param name="pDecFrame">图像信息</param>
        /// <param name="uFlags">解码模式 0：正常解码；1、解码完毕并要求解码器输出残留图像</param>
        /// <returns></returns>
        [DllImport("hi_h264dec_w.dll", EntryPoint = "Hi264DecFrame", CallingConvention = CallingConvention.Cdecl)]
        public static extern int Hi264DecFrame(IntPtr hDec, IntPtr pStream, uint iStreamLen, ulong ullPTS, ref hiH264_DEC_FRAME_S pDecFrame, uint uFlags);

        [DllImport("hi_h264dec_w.dll", EntryPoint = "Hi264DecAU", CallingConvention = CallingConvention.Cdecl)]
        public static extern int Hi264DecAU(IntPtr hDec, IntPtr pStream, uint iStreamLen, ulong ullPTS, ref hiH264_DEC_FRAME_S pDecFrame, uint uFlags);
        /// <summary>
        /// 解码器属性信息。
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct hiH264_DEC_ATTR_S
        {
            /// <summary>
            /// 解码器输出图像格式，目前解码库只支持YUV420图像格式
            /// </summary>
            public uint uPictureFormat;
            /// <summary>
            /// 输入码流格式 0x00: 目前解码库只支持以“00 00 01”为nalu分割符的流式H.264码流 
            /// </summary>
            public uint uStreamInType;
            /// <summary>
            /// 图像宽度
            /// </summary>
            public uint uPicWidthInMB;
            /// <summary>
            /// 图像高度
            /// </summary>
            public uint uPicHeightInMB;
            /// <summary>
            /// 参考帧数目
            /// </summary>
            public uint uBufNum;
            /// <summary>
            /// 解码器工作模式
            /// </summary>
            public uint uWorkMode;
            /// <summary>
            /// 用户私有数据
            /// </summary>
            public IntPtr pUserData;
            /// <summary>
            /// 保留字
            /// </summary>
            public uint uReserved;

        }

        /// <summary>
        /// 解码器输出图像信息数据结构
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct hiH264_DEC_FRAME_S
        {
            /// <summary>
            /// Y分量地址
            /// </summary>
            public IntPtr pY;
            /// <summary>
            /// U分量地址
            /// </summary>
            public IntPtr pU;
            /// <summary>
            /// V分量地址
            /// </summary>
            public IntPtr pV;
            /// <summary>
            /// 图像宽度(以像素为单位)
            /// </summary>
            public uint uWidth;
            /// <summary>
            /// 图像高度(以像素为单位)
            /// </summary>
            public uint uHeight;
            /// <summary>
            /// 输出Y分量的stride (以像素为单位)
            /// </summary>
            public uint uYStride;
            /// <summary>
            /// 输出UV分量的stride (以像素为单位)
            /// </summary>
            public uint uUVStride;
            /// <summary>
            /// 图像裁减信息:左边界裁减像素数
            /// </summary>
            public uint uCroppingLeftOffset;
            /// <summary>
            /// 图像裁减信息:右边界裁减像素数
            /// </summary>
            public uint uCroppingRightOffset;
            /// <summary>
            /// 图像裁减信息:上边界裁减像素数
            /// </summary>
            public uint uCroppingTopOffset;
            /// <summary>
            /// 图像裁减信息:下边界裁减像素数
            /// </summary>
            public uint uCroppingBottomOffset;
            /// <summary>
            /// 输出图像在dpb中的序号
            /// </summary>
            public uint uDpbIdx;
            /// <summary>
            /// 图像类型：0:帧; 1:顶场; 2:底场 */
            /// </summary>
            public uint uPicFlag;
            /// <summary>
            /// 图像类型：0:帧; 1:顶场; 2:底场 */
            /// </summary>
            public uint bError;
            /// <summary>
            /// 图像是否为IDR帧：0:非IDR帧;1:IDR帧
            /// </summary>
            public uint bIntra;
            /// <summary>
            /// 时间戳
            /// </summary>
            public ulong ullPTS;
            /// <summary>
            /// 图像信号
            /// </summary>
            public uint uPictureID;
            /// <summary>
            /// 保留字
            /// </summary>
            public uint uReserved;
            /// <summary>
            /// 指向用户私有数据
            /// </summary>
            public IntPtr pUserData;

        }


        /// <summary>
        /// 解码库版本、版权和能力集信息。
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct hiH264_LIBINFO_S
        {
            /// <summary>
            /// 主编号
            /// </summary>
            public uint uMajor;
            /// <summary>
            /// 次编号
            /// </summary>
            public uint uMinor;
            /// <summary>
            /// 发布编号
            /// </summary>
            public uint uRelease;
            /// <summary>
            /// 建构编号
            /// </summary>
            public uint uBuild;
            /// <summary>
            /// 版本信息
            /// </summary>
            [MarshalAs(UnmanagedType.LPStr)]
            public string sVersion;
            /// <summary>
            /// 版权信息
            /// </summary>
            [MarshalAs(UnmanagedType.LPStr)]
            public string sCopyRight;
            /// <summary>
            /// 解码库能力集
            /// </summary>
            public uint uFunctionSet;
            /// <summary>
            /// 支持的输出图像格式
            /// </summary>
            public uint uPictureFormat;
            /// <summary>
            /// 输入码流格式
            /// </summary>
            public uint uStreamInType;
            /// <summary>
            /// 最大图像宽度(以像素为单位)
            /// </summary>
            public uint uPicWidth;
            /// <summary>
            /// 最大图像高度(以像素为单位)
            /// </summary>
            public uint uPicHeight;
            /// <summary>
            /// 最大参考帧数目
            /// </summary>
            public uint uBufNum;
            /// <summary>
            /// 保留字
            /// </summary>
            public uint uReserved;

        }

        /// <summary>
        /// 用户私有数据信息。
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct hiH264_USERDATA_S
        {
            /// <summary>
            /// 用户数据类型
            /// </summary>
            public uint uUserDataType;
            /// <summary>
            /// 用户数据长度
            /// </summary>
            public uint uUserDataSize;
            /// <summary>
            /// 用户数据缓冲区
            /// </summary>
            public IntPtr pData;
            /// <summary>
            /// 指向下一段用户数据
            /// </summary>
            public IntPtr pNext;
        }
    }

View Code

　　这是YUV转RGB图像。

        /// <summary>
        /// 将转换后的 RGB 图像数据按照 BMP 格式写入文件。
        /// </summary>
        /// <param name="rgbFrame">RGB 格式图像数据。</param>
        /// <param name="width">图像宽（单位：像素）。</param>
        /// <param name="height">图像高（单位：像素）。</param>
        /// <param name="bmpFile"> BMP 文件名。</param>
        static void WriteBMP(byte[] rgbFrame, int width, int height, string bmpFile)
        {
            // 写 BMP 图像文件。
            int yu = width * 3 % 4;
            int bytePerLine = 0;
            yu = yu != 0 ? 4 - yu : yu;
            bytePerLine = width * 3 + yu;

            using (FileStream fs = File.Open(bmpFile, FileMode.Create))
            {
                using (BinaryWriter bw = new BinaryWriter(fs))
                {
                    bw.Write('B');
                    bw.Write('M');
                    bw.Write(bytePerLine * height + 54);
                    bw.Write(0);
                    bw.Write(54);
                    bw.Write(40);
                    bw.Write(width);
                    bw.Write(height);
                    bw.Write((ushort)1);
                    bw.Write((ushort)24);
                    bw.Write(0);
                    bw.Write(bytePerLine * height);
                    bw.Write(0);
                    bw.Write(0);
                    bw.Write(0);
                    bw.Write(0);

                    byte[] data = new byte[bytePerLine * height];
                    int gIndex = width * height;
                    int bIndex = gIndex * 2;

                    for (int y = height - 1, j = 0; y >= 0; y--, j++)
                    {
                        for (int x = 0, i = 0; x < width; x++)
                        {
                            data[y * bytePerLine + i++] = rgbFrame[bIndex + j * width + x];    // B
                            data[y * bytePerLine + i++] = rgbFrame[gIndex + j * width + x];    // G
                            data[y * bytePerLine + i++] = rgbFrame[j * width + x];  // R
                        }
                    }

                    bw.Write(data, 0, data.Length);
                    bw.Flush();
                }
            }
        }

        /// <summary>
        /// 将一桢 YUV 格式的图像转换为一桢 RGB 格式图像。
        /// </summary>
        /// <param name="yuvFrame">YUV 格式图像数据。</param>
        /// <param name="rgbFrame">RGB 格式图像数据。</param>
        /// <param name="width">图像宽（单位：像素）。</param>
        /// <param name="height">图像高（单位：像素）。</param>
        static void ConvertYUV2RGB(byte[] yuvFrame, byte[] rgbFrame, int width, int height)
        {
            int uIndex = width * height;
            int vIndex = uIndex + ((width * height) >> 2);
            int gIndex = width * height;
            int bIndex = gIndex * 2;

            int temp = 0;

            for (int y = 0; y < height; y++)
            {
                for (int x = 0; x < width; x++)
                {
                    // R分量
                    temp = (int)(yuvFrame[y * width + x] + (yuvFrame[vIndex + (y / 2) * (width / 2) + x / 2] - 128) * YUV2RGB_CONVERT_MATRIX[0, 2]);
                    rgbFrame[y * width + x] = (byte)(temp < 0 ? 0 : (temp > 255 ? 255 : temp));

                    // G分量
                    temp = (int)(yuvFrame[y * width + x] + (yuvFrame[uIndex + (y / 2) * (width / 2) + x / 2] - 128) * YUV2RGB_CONVERT_MATRIX[1, 1] + (yuvFrame[vIndex + (y / 2) * (width / 2) + x / 2] - 128) * YUV2RGB_CONVERT_MATRIX[1, 2]);
                    rgbFrame[gIndex + y * width + x] = (byte)(temp < 0 ? 0 : (temp > 255 ? 255 : temp));

                    // B分量
                    temp = (int)(yuvFrame[y * width + x] + (yuvFrame[uIndex + (y / 2) * (width / 2) + x / 2] - 128) * YUV2RGB_CONVERT_MATRIX[2, 1]);
                    rgbFrame[bIndex + y * width + x] = (byte)(temp < 0 ? 0 : (temp > 255 ? 255 : temp));
                }
            }
        }

View Code

　　

3、这可能就是我遇到问题的地方了，怎么把RTPPack中的包数据转换为一帧图像信息，我找到的资料是;

　　

#region 对收到的数据进行处理
            if (!Clients.ContainsKey(packet.SSRC))//如果接受端第一次接受到某源的数据，则加入到
            {
                if (Clients.Count < 4)//如果发送端为4，则丢弃包
                {
                    Clients.Add(packet.SSRC, new List<RTPPacket> { packet });
                    //ImagesBoxMapping[ImagesBoxMapping.First(pair => pair.Value == null).Key] = packet.SSRC;
                }
            }
            else
            {
                Clients[packet.SSRC].Add(packet);
            }

            if (packet.Marker)//如果已经发送完毕
            {
                //丢包检测
                var orderPackets = Clients[packet.SSRC].OrderBy(rtpPacket => rtpPacket.SequenceNumber);
                if (Clients[packet.SSRC].Count != (orderPackets.Last().SequenceNumber - orderPackets.First().SequenceNumber + 1))
                {
                    Clients[packet.SSRC].Clear();//清空缓存区
                    return true;
                }

                //1.包重组
                var count = Clients[packet.SSRC].Sum(rtpPacket => rtpPacket.DataSize);//数据总数

                var newData = new byte[count];

                long offSet = 0;
                foreach (var rtpPacket in Clients[packet.SSRC])
                {
                    Array.Copy(rtpPacket.DataPointer, 0, newData, offSet, rtpPacket.DataSize);
                    offSet += rtpPacket.DataSize;
                }
                Clients[packet.SSRC].Clear();//清空缓存区

　　这里我理解的是newData里面就是一帧数据，但我测试了一下不对（晕）。

　　4、总结

　　这几天一直想要尽快做出来，却总没有办法深入去研究视频方面的东西。比如得到的包怎么变为一帧，怎么从一帧里面提取需要的数据，什么PPS、SPS、IDR都是什么，虽然知道名词，但总没法很明确的说出来。

　　我的解码思路是：RTP协议收到包后（这一步没有问题），将包的数据转为帧（这个地方可能出问题了，也可能是传过来的帧数据不符合解码的要求），再把一帧的数据传给H264解码类解码，解码后输出的是YUV，YUV->RGB->图片进行显示就可以了。这是我的思路，但没有成功。如果读者您懂这一方面，还希望给我指导。谢谢

　　每天写一点点，就能进步一点点.